AIM To find out the difference of humanprimary liver carcinogenesis between Han andminority ethnic patients in Xinjiang.METHODS Expression of p53,c-erbB-2,H-rasp21 protein and proliferating cell nuclearantigen(PCNA)in...AIM To find out the difference of humanprimary liver carcinogenesis between Han andminority ethnic patients in Xinjiang.METHODS Expression of p53,c-erbB-2,H-rasp21 protein and proliferating cell nuclearantigen(PCNA)in tumor tissues of 50 patients(Han 38,minority 12)with primary hepaticcarcinoma was detected byimmunohistochemistry(LSAB).RESULTS The positive frequency of p53,c-erbB-2,H-rasp21 and PCNA expression was46.0%(23/50),70.0%(35/50),68.0%(34/50)and 82.0%(41/50)in tumor tissues;4.0%(2/50),22.0%(11/50),64.0%(32/50)and 52.0%(26/ 50)in peritumors respectively and asignificant difference,except for H-rasp21,ofoncogene alteration was found(P【0.05)between tumor and non-tumorous tissues.Combined the three oncogenes alteration,26%(13/50)tumor tissues had positiveimmunoreactivity,but in peritumor and normallivers it was negative.The positive rate of p53,c-erbB-2 and H-rasp21 protein expression was39.5%(15/38),60.5%(23/38)and 39.5%(15/38)in tumors of Han patients;66.7%(8/12),100%(12/12)and 75.0%(9/12)in minoritiesrespectively,with statistical difference (P【0.05).CONCLUSION Overexpression of p53,c-erbB-2and H-rasp21 in human primary liver carcinoma isan important biomarker of genetic alteration.The different frequency of these oncogeneticchanges may reflect some environmental or/andethnic hereditary factors affecting the livercarcinogenesis.The special life style of Han,Uygur,Kazak and Mongolia nationalities inXinjiang may also be related to theetiopathogenesis of this disease.展开更多
AIM: To investigate both whether the risk of gastric cancer is associated with the Ile/Val single nucleotide polymorphism (SNP) of human epidermal growth factor receptor-2 (HER-2) transmembrane domain-coding regi...AIM: To investigate both whether the risk of gastric cancer is associated with the Ile/Val single nucleotide polymorphism (SNP) of human epidermal growth factor receptor-2 (HER-2) transmembrane domain-coding region at codon 655 and the suggested existence of HER-2 expression in gastric cancer cases in a Turkish patient group. METHODS: Polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) strategy was used to analyze the presence of HER-2 SNP at codon 655. c-erbB-2 expression pattern was analyzed by immunohistochemistry. The results were compared between gastric carcinoma group and chronic gastritis group, as well as between clinicopathological parameters and carcinoma. RESULTS: Results showed that Ile/Val genotype accounted for 20% within the Turkish gastric carcinoma group, and none in chronic gastritis group, and this genotyping was associated with stage Ⅳ gastric cancers (P = 0.04). Positive membranous HER-2 immunoreactivity, on the other hand, accounted for 24% within the Turkish gastric carcinoma group and none from chronic gastritis cases; further, it was correlated with intestinal type carcinomas (P = 0.007), and stage Ⅲ-Ⅳ carcinomas (P = 0.004). CONCLUSION: These observations imply that the tested HER-2 SNP may participate in the development and progression of gastric cancer. Thus, after confirming these results with large sample groups, HER-2 codon 655 SNP and/or c-erbB-2 overexpression may also be used as a poor prognostic indicator for gastric carcinomas.展开更多
In this editorial,the roles of protein tyrosine phosphatase nonreceptor 2(PTPN2)in oncogenic transformation and tumor behavior and its potential as a therapeutic target in the context of gastrointestinal(GI)cancers ar...In this editorial,the roles of protein tyrosine phosphatase nonreceptor 2(PTPN2)in oncogenic transformation and tumor behavior and its potential as a therapeutic target in the context of gastrointestinal(GI)cancers are presented with respect to the article by Li et al published in ninth issue of the World Journal of Gastrointestinal Oncology.PTPN2 is a member of the protein tyrosine phosphatase family of signaling proteins that play crucial roles in the regulation of inflammation and immunity.Accordingly,early findings highlighted the contribution of PTPN2 to the pathogenesis of inflammatory and autoimmune disorders related to its dysfunction.On the other hand,recent studies have indicated that PTPN2 has many different roles in different cancer types,which is associated with the complexity of its regulatory network.PTPN2 dephosphorylates and inactivates EGFR,SRC family kinases,JAK1 and JAK3,and STAT1,STAT3,and STAT5 in cell type-and context-dependent manners,which indicates that PTPN2 can perform either prooncogenic or anti-oncogenic functions depending on the tumor subtype.While PTPN2 has been suggested as a potential therapeutic target in cancer treatment,to the best of ourknowledge,no clear treatment protocol has referred to PTPN2.Although there are only few studies that investigated PTPN2 expression in the GI system cancers,which is a potential limitation,the association of this protein with tumor behavior and the influence of PTPN2 on many therapy-related signaling pathways emphasize that PTPN2 could serve as a new molecular biomarker to predict tumor behavior and as a target for therapeutic intervention against GI cancers.In conclusion,more studies should be performed to better understand the prognostic and therapeutic potential of PTPN2 in GI tumors,especially in tumors resistant to therapy.展开更多
BACKGROUND Serum retinol-binding protein(RBP)is the primary transport protein of circulating vitamin A.RBP has a crucial role in maintaining nutrient metabolism and physiologic homeostasis.Several studies have indicat...BACKGROUND Serum retinol-binding protein(RBP)is the primary transport protein of circulating vitamin A.RBP has a crucial role in maintaining nutrient metabolism and physiologic homeostasis.Several studies have indicated that serum RBP participates in the progression of diabetes and diabetes-related complications.However,the impact of serum RBP on lower limb atherosclerosis has not been determined in individuals with type 2 diabetes mellitus(T2DM).AIM To determine the association between serum RBP and lower limb atherosclerosis in individuals with T2DM.METHODS This retrospective study enrolled 4428 eligible T2DM patients and divided the patients into non-lower limb atherosclerosis(n=1913)and lower limb atherosclerosis groups(n=2515)based on lower limb arterial ultrasonography results.At hospital admission,baseline serum RBP levels were assessed,and all subjects were categorized into three groups(Q1-Q3)based on RBP tertiles.Logistic regression,restricted cubic spline regression,subgroup analysis,and machine learning were used to assess the association between RBP levels and lower limb atherosclerosis risk.RESULTS Among 4428 individuals with T2DM,2515(56.80%)had lower limb atherosclerosis.Logistic analysis showed that lower limb atherosclerosis risk increased by 1%for every 1 unit rise in serum RBP level(odds ratio=1.01,95%confidence interval:1.00-1.02,P=0.004).Patients in the highest tertile group(Q3)had a higher lower limb atherosclerosis risk compared to the lowest tertile group(Q1)(odds ratio=1.36,95%confidence interval:1.12-1.67,P=0.002).The lower limb atherosclerosis risk gradually increased with an increase in RBP tertile(P for trend=0.005).Restricted cubic spline analysis indicated a linear correlation between serum RBP levels and lower limb atherosclerosis risk(non-linear P<0.05).Machine learning demonstrated the significance and diagnostic value of serum RBP in predicting lower limb atherosclerosis risk.CONCLUSION Elevated serum RBP levels correlate with an increased lower limb atherosclerosis risk in individuals with T2DM.展开更多
BACKGROUND Unraveling the pathogenesis of colorectal cancer(CRC)can aid in developing prevention and treatment strategies.Aurora kinase A(AURKA)is a key participant in mitotic control and interacts with its co-activat...BACKGROUND Unraveling the pathogenesis of colorectal cancer(CRC)can aid in developing prevention and treatment strategies.Aurora kinase A(AURKA)is a key participant in mitotic control and interacts with its co-activator,the targeting protein for Xklp2(TPX2)microtubule nucleation factor.AURKA is associated with poor clinical outcomes and high risks of CRC recurrence.AURKA/TPX2 co-overexpression in cancer may contribute to tumorigenesis.Despite its pivotal role in CRC development and progression,the action mechanism of AURKA remains unclear.Further research is needed to explore the complex interplay between AURKA and TPX2 and to develop effective targeted treatments for patients with CRC.AIM To compare effects of AURKA and TPX2 and their combined knockdown on CRC cells.METHODS We evaluated three CRC gene datasets about CRC(GSE32323,GSE25071,and GSE21510).Potential hub genes associated with CRC onset were identified using the Venn,search tool for the retrieval of interacting genes,and KOBAS platforms,with AURKA and TPX2 emerging as significant factors.Subsequently,cell models with knockdown of AURKA,TPX2,or both were constructed using SW480 and LOVO cells.Quantitative real-time polymerase chain reaction,western blotting,cell counting kit-8,cell cloning assays,flow cytometry,and Transwell assays were used.RESULTS Forty-three highly expressed genes and 39 poorly expressed genes overlapped in cancer tissues compared to controls from three datasets.In the protein-protein interaction network of highly expressed genes,AURKA was one of key genes.Its combined score with TPX2 was 0.999,and their co-expression score was 0.846.In CRC cells,knockdown of AURKA,TPX2,or both reduced cell viability and colony number,while blocking G0/G1 phase and enhancing cell apoptosis.Additionally,they were weakened cell proliferation and migration abilities.Furthermore,the expression levels of B-cell lymphoma-2-Associated X,caspase 3,and tumor protein P53,and E-cadherin increased with a decrease in B-cell lymphoma-2,N-cadherin,and vimentin proteins.These effects were amplified when both AURKA and TPX2 were concurrently downregulated.CONCLUSION Combined knockdown of AURKA and TPX2 was effective in suppressing the malignant phenotype in CRC.Coinhibition of gene expression is a potential developmental direction for CRC treatment.展开更多
Objective: To investigate the correlation between c-erbB-2 and multidrug resistance (MDR) and its clinical significance, Methods: Immunohistochemistry stain was used to examine the expression of c-erbB-2 and flow ...Objective: To investigate the correlation between c-erbB-2 and multidrug resistance (MDR) and its clinical significance, Methods: Immunohistochemistry stain was used to examine the expression of c-erbB-2 and flow cytometry was used to detect the expression of P-glycoprotein (P-gp) in samples from 46 patients with esophageal carcinoma. Results: The positive expression rate of c-erbB-2 was 26.1% (12/46) in the 46 cases of esophageal carcinoma, of which 4 cases being low expression and 8 cases mediumhigh expression. The positive expression rate of P-gp was 60.9% (28/46) in the 46 cases of esophageal carcinoma, of which 6 cases being low expression, 13 cases medium expression and 9 cases high expression. Comparing c-erbB-2 with P-gp expression in different lymph node metastasis statuses showed that there was significant difference (P〈0.01) between P-gp expressions with lymph node metastasis (31.09%±5.33%) and without lymph node metastasis (8.04%±3.03%) when c-erbB-2 expression was positive. Comparing c-erbB-2 with P-gp expression in different TNM stages of esophageal carcinoma showed that there was significant difference (P〈0.01) between P-gp expressions in HI Ⅳ stage (33.68%±5.51%)and in Ⅱ stage patients (9.30%±2.78%) when c-erbB-2 expression was positive. The tumor's size and differentiation degree were not related to c-erbB-2 and P-gp expression. Conclusion: The high level of P-gp expression was related to the positive expression of c-erbB-2 with the lymph node metastasis in clinical Ⅲ-Ⅳ stage patients of esophageal carcinoma, suggesting that the double positive might lead to a poor prognosis. However, when the c-erbB-2 expression was negative, the lymph node metastasis and clinical staging were not related to the P-gp expression in esophageal carcinoma patients.展开更多
Low-density lipoprotein receptor-related protein 2(LRP2)is a multifunctional endocytic receptor expressed in epithelial cells.In mammals,it acts as an endocytic receptor that mediates the cellular uptake of cholestero...Low-density lipoprotein receptor-related protein 2(LRP2)is a multifunctional endocytic receptor expressed in epithelial cells.In mammals,it acts as an endocytic receptor that mediates the cellular uptake of cholesterol-containing apolipoproteins to maintain lipid homeostasis.However,little is known about the role of LRP2 in lipid homeostasis in insects.In the present study,we investigated the function of LRP2 in the migratory locust Locusta migratoria(LmLRP2).The mRNA of LmLRP2 is widely distributed in various tissues,including integument,wing pads,foregut,midgut,hindgut,Malpighian tubules and fat body,and the amounts of LmLRP2 transcripts decreased gradually in the early stages and then increased in the late stages before ecdysis during the nymphal developmental stage.Fluorescence immunohistochemistry revealed that the LmLRP2 protein is mainly located in cellular membranes of the midgut and hindgut.Using RNAi to silence LmLRP2 caused molting defects in nymphs(more than 60%),and the neutral lipid was found to accumulate in the midgut and surface of the integument,but not in the fat body,of dsLmLRP2-treated nymphs.The results of a lipidomics analysis showed that the main components of lipids(diglyceride and triglyceride)were significantly increased in the midgut,but decreased in the fat body and hemolymph.Furthermore,the content of total triglyceride was significantly increased in the midgut,but markedly decreased in the fat body and hemolymph in dsLmLRP2-injected nymphs.Our results indicate that LmLRP2 is located in the cellular membranes of midgut cells,and is required for lipid export from the midgut to the hemolymphand fat body in locusts.展开更多
BACKGROUND Recently,type 2 diabetic osteoporosis(T2DOP)has become a research hotspot for the complications of diabetes,but the specific mechanism of its occurrence and development remains unknown.Ferroptosis caused by...BACKGROUND Recently,type 2 diabetic osteoporosis(T2DOP)has become a research hotspot for the complications of diabetes,but the specific mechanism of its occurrence and development remains unknown.Ferroptosis caused by iron overload is con-sidered an important cause of T2DOP.Polycytosine RNA-binding protein 1(PCBP1),an iron ion chaperone,is considered a protector of ferroptosis.AIM To investigate the existence of ferroptosis and specific role of PCBP1 in the development of type 2 diabetes.METHODS A cell counting kit-8 assay was used to detect changes in osteoblast viability under high glucose(HG)and/or ferroptosis inhibitors at different concentrations and times.Transmission electron microscopy was used to examine the morpho-logical changes in the mitochondria of osteoblasts under HG,and western blotting was used to detect the expression levels of PCBP1,ferritin,and the ferroptosis-related protein glutathione peroxidase 4(GPX4).A lentivirus silenced and overex-pressed PCBP1.Western blotting was used to detect the expression levels of the osteoblast functional proteins osteoprotegerin(OPG)and osteocalcin(OCN),whereas flow cytometry was used to detect changes in reactive oxygen species(ROS)levels in each group.RESULTS Under HG,the viability of osteoblasts was considerably decreased,the number of mitochondria undergoing atrophy was considerably increased,PCBP1 and ferritin expression levels were increased,and GPX4 expression was decreased.Western blotting results demonstrated that infection with lentivirus overexpressing PCBP1,increased the expression levels of ferritin,GPX4,OPG,and OCN,compared with the HG group.Flow cytometry results showed a reduction in ROS,and an opposite result was obtained after silencing PCBP1.CONCLUSION PCBP1 may protect osteoblasts and reduce the harm caused by ferroptosis by promoting ferritin expression under a HG environment.Moreover,PCBP1 may be a potential therapeutic target for T2DOP.展开更多
Objective: To detect the relations of c-erbB-2 onco-gene protein, epidermal growth factor receptor (EG-FR) and transforming growth factor-β1 (TGF-β1)to the progression or metastasis of pancreatic carci-noma.Methods:...Objective: To detect the relations of c-erbB-2 onco-gene protein, epidermal growth factor receptor (EG-FR) and transforming growth factor-β1 (TGF-β1)to the progression or metastasis of pancreatic carci-noma.Methods: Using streptavidinbiotin complex (SABC)method, c-erbB-2 oncongene protein, we examinedimmunohistochemically EGFR and TGF-β1 expres-sions in wax-tissue sections from 10 individuals withnormal pancreas (NP), 13 patients with chronic pan-creatitis (CP) and 36 patients with pancreatic ductaladenocarcinoma (PC).Results: The positive expression rates of c-cerbB-2oncogene protein, EGFR and TGF-β1 in the NP, CPand PC groups were 0, 0, 10%; 7.7%, 7.7%,7.7%; and 41.7%, 50.0%, 44.4%, respectively.The positive expression rates of the three specific pro-teins increased more significantly in the PC groupthan in the NP and CP groups (P【0.05). The indi-vidual expression of c-erbB-2, EGFR and TGF-β1was not related to the age and sex of the patients aswell as the site, size and histopathological grade oftumors (P】0.05), but to the clinical stage of tumors(P【0.01). The coexpression rate of the three pro-teins was 27.8 % (10/36). This coexpression in thePC group was correlated with the histopathologicalgrades and clinical stages of tumors (P【0.01).Conclusion: Detection of c-erbB-2 oncogene protein,EGFR, and TGF-β1 expressions in pancreatic tissueis helpful to judge the malignancy, progression, andmetastasis of PC.展开更多
As the global demographic shifts toward an aging population,understanding the efficiency of protein uti-lization in older adults becomes crucial.Our study explores the intricate relationship between protein intake and...As the global demographic shifts toward an aging population,understanding the efficiency of protein uti-lization in older adults becomes crucial.Our study explores the intricate relationship between protein intake and aging,with a focus on precision nutrition for older people.Through a meta-analysis,we con-firm a decline in protein-utilization capacity in older individuals and examine the different contributions of plant and animal protein.In experiments involving mice of different ages,older mice exhibited decreases in the biological utilization of four proteins(casein,beef protein,soy protein,and gluten),par-ticularly casein.In subsequent research,casein was studied as a key protein.A decline in gastric digestion function was observed through peptidomics and the examination of pepsin levels using casein.Nevertheless,this decline did not significantly affect the overall protein digestion during the aging pro-cess.The combined application of targeted amino acid metabolomics identified abnormal absorption of amino acids as the underlying cause of decreased protein utilization during aging,particularly emphasiz-ing a reduction in branched-chain amino acids(BCAAs)in older mice.Delving deeper into the proteomics of the intestinal protein digestion and absorption pathway,a reduction of over 60%in large neutral amino acid transporter 2(LAT2)protein expression was observed in both older humans and aged mice.The reduction in LAT2 protein was found to be a key factor influencing the diminished BCAA availability.Overall,our study establishes the significance of amino acid absorption through LAT2 in protein utiliza-tion during aging and offers a new theoretical foundation for improving protein utilization in the older adults.展开更多
Walnut dreg protein hydrolysates(WDPHs)exhibit a variety of biological activities,however,the cyclooxygenase-2(COX-2)inhibitory peptide of WDPHs remain unclear.The aim of this study was to rapidly screen for such pept...Walnut dreg protein hydrolysates(WDPHs)exhibit a variety of biological activities,however,the cyclooxygenase-2(COX-2)inhibitory peptide of WDPHs remain unclear.The aim of this study was to rapidly screen for such peptides in WDPHs through a combination of in silico and in vitro analysis.In total,1262 peptide sequences were observed by nano liquid chromatography/tandem mass spectrometry(nano LC-MS/MS)and 4 novel COX-2 inhibitory peptides(AGFP,FPGA,LFPD,and VGFP)were identified.Enzyme kinetic data indicated that AGFP,FPGA,and LFPD displayed mixed-type COX-2 inhibition,whereas VGFP was a non-competitive inhibitor.This is mainly because the peptides form hydrogen bonds and hydrophobic interactions with residues in the COX-2 active site.These results demonstrate that computer analysis combined with in vitro evaluation allows for rapid screening of COX-2 inhibitory peptides in walnut protein dregs.展开更多
BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untran...BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untranslated region(UTR)point mutations in ankyrin repeat domain containing 26(ANKRD26).Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1)have been identified as negative regulators of ANKRD26.However,the positive regulators of ANKRD26 are still unknown.AIM To prove the positive regulatory effect of GATA binding protein 2(GATA2)on ANKRD26 transcription.METHODS Human induced pluripotent stem cells derived from bone marrow(hiPSC-BM)INTRODUCTION Ankyrin repeat domain containing protein 26(ANKRD26)acts as a regulator of adipogenesis and is involved in the regulation of feeding behavior[1-3].The ANKRD26 gene is located on chromosome 10 and shares regions of homology with the primate-specific gene family POTE.According to the Human Protein Atlas database,the ANKRD26 protein is localized to the Golgi apparatus and vesicles,and its expression can be detected in nearly all human tissues[4].Moreover,UniProt annotation revealed that ANKRD26 is localized in the centrosome and contains coiled-coil domains formed by spectrin helices and ankyrin repeats[5,6].The most common disease related to ANKRD26 is thrombocytopenia 2(THC2),which is a rare autosomal dominant inherited disease characterized by lifelong mild-to-moderate thrombocytopenia and mild bleeding[7-9].Caused by the variants in the 5’-untranslated region(UTR)of ANKRD26,THC2 is defined by a decrease in the number of platelets in circulating blood and results in increased bleeding and decreased clotting ability[8,10].Due to the point mutations that occur in the 5’-UTR of ANKRD26,its negative transcription factors(TFs),Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1),lose their repression effect[11].The persistent expression of ANKRD26 increases the activity of the mitogen activated protein kinase and extracellular signal regulated kinase 1/2 signaling pathways,which are potentially involved in the regulation of thrombopoietin-dependent signaling and further impair proplatelet formation by megakaryocytes(MKs)[11].However,the positive regulators of ANKRD26,which might be associated with THC2 pathology,are still unknown.展开更多
Objective: To understand the relationship between C-erbB-2 and multidrug resistance (MDR) as well as its clinical significance. Methods: P-gp level was detected by flow cytometry and simultaneously to examine the ...Objective: To understand the relationship between C-erbB-2 and multidrug resistance (MDR) as well as its clinical significance. Methods: P-gp level was detected by flow cytometry and simultaneously to examine the C-erbB-2 expression level by immunohistochemistry assay in the operating samples. Their relationship was analyzed from 59 cases with gastric carcinoma. Results: The P-gp positive expression was 38/59 (64.4%) cases with gastric carcinoma. The C-erbB-2 positive expression was 21/59 (35.6%) cases with gastric carcinoma. From the analysis of the P-gp and C-erbB-2 relationship, which was involving, range in the gastric carcinoma, that involving two or three sites were more than the site one, in the cases with C-erbB-2 negative. Compared this two groups, there was a significant difference (P = 0.026). When the C-erbB-2 was positive, the P-gp expression had a significant difference (P = 0.04) in comparing the Ⅲ-Ⅳ stage (lymph node metastasis) with Ⅰ-Ⅱ stage (without lymph node metastasis). The tumor's size, differentiation degree, ages and sex were not related to the C-erbB- 2 and P-gp expression. Conclusion: High level of P-gp expression was related to the C-erbB-2 positive expression in clinical Ⅲ-Ⅳ stage patient with gastric carcinoma (lymph node metastasis). It suggested that the double positive patient might be a poor prognosis. However, when the C-erbB-2 was negative expression, the clinical staging (with lymph node metastasis) was not related to the P-gp expression in gastric carcinoma patients.展开更多
Pancreatic ductal adenocarcinoma(PDAC)is one of the most aggressive solid malignancies.A specific mechanism of its metastasis has not been established.In this study,we investigated whether Neural Wiskott-Aldrich syndr...Pancreatic ductal adenocarcinoma(PDAC)is one of the most aggressive solid malignancies.A specific mechanism of its metastasis has not been established.In this study,we investigated whether Neural Wiskott-Aldrich syndrome protein(N-WASP)plays a role in distant metastasis of PDAC.We found that N-WASP is markedly expressed in clinical patients with PDAC.Clinical analysis showed a notably more distant metastatic pattern in the N-WASP-high group compared to the N-WASP-low group.N-WASP was noted to be a novel mediator of epithelialmesenchymal transition(EMT)via gene expression profile studies.Knockdown of N-WASP in pancreatic cancer cells significantly inhibited cell invasion,migration,and EMT.We also observed positive association of lysyl oxidase-like 2(LOXL2)and focal adhesion kinase(FAK)with the N-WASP-mediated response,wherein EMT and invadopodia function were modulated.Both N-WASP and LOXL2 depletion significantly reduced the incidence of liver and lung metastatic lesions in orthotopic mouse models of pancreatic cancer.These results elucidate a novel role for N-WASP signaling associated with LOXL2 in EMT and invadopodia function,with respect to regulation of intercellular communication in tumor cells for promoting pancreatic cancer metastasis.These findings may aid in the development of therapeutic strategies against pancreatic cancer.展开更多
文摘AIM To find out the difference of humanprimary liver carcinogenesis between Han andminority ethnic patients in Xinjiang.METHODS Expression of p53,c-erbB-2,H-rasp21 protein and proliferating cell nuclearantigen(PCNA)in tumor tissues of 50 patients(Han 38,minority 12)with primary hepaticcarcinoma was detected byimmunohistochemistry(LSAB).RESULTS The positive frequency of p53,c-erbB-2,H-rasp21 and PCNA expression was46.0%(23/50),70.0%(35/50),68.0%(34/50)and 82.0%(41/50)in tumor tissues;4.0%(2/50),22.0%(11/50),64.0%(32/50)and 52.0%(26/ 50)in peritumors respectively and asignificant difference,except for H-rasp21,ofoncogene alteration was found(P【0.05)between tumor and non-tumorous tissues.Combined the three oncogenes alteration,26%(13/50)tumor tissues had positiveimmunoreactivity,but in peritumor and normallivers it was negative.The positive rate of p53,c-erbB-2 and H-rasp21 protein expression was39.5%(15/38),60.5%(23/38)and 39.5%(15/38)in tumors of Han patients;66.7%(8/12),100%(12/12)and 75.0%(9/12)in minoritiesrespectively,with statistical difference (P【0.05).CONCLUSION Overexpression of p53,c-erbB-2and H-rasp21 in human primary liver carcinoma isan important biomarker of genetic alteration.The different frequency of these oncogeneticchanges may reflect some environmental or/andethnic hereditary factors affecting the livercarcinogenesis.The special life style of Han,Uygur,Kazak and Mongolia nationalities inXinjiang may also be related to theetiopathogenesis of this disease.
文摘AIM: To investigate both whether the risk of gastric cancer is associated with the Ile/Val single nucleotide polymorphism (SNP) of human epidermal growth factor receptor-2 (HER-2) transmembrane domain-coding region at codon 655 and the suggested existence of HER-2 expression in gastric cancer cases in a Turkish patient group. METHODS: Polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) strategy was used to analyze the presence of HER-2 SNP at codon 655. c-erbB-2 expression pattern was analyzed by immunohistochemistry. The results were compared between gastric carcinoma group and chronic gastritis group, as well as between clinicopathological parameters and carcinoma. RESULTS: Results showed that Ile/Val genotype accounted for 20% within the Turkish gastric carcinoma group, and none in chronic gastritis group, and this genotyping was associated with stage Ⅳ gastric cancers (P = 0.04). Positive membranous HER-2 immunoreactivity, on the other hand, accounted for 24% within the Turkish gastric carcinoma group and none from chronic gastritis cases; further, it was correlated with intestinal type carcinomas (P = 0.007), and stage Ⅲ-Ⅳ carcinomas (P = 0.004). CONCLUSION: These observations imply that the tested HER-2 SNP may participate in the development and progression of gastric cancer. Thus, after confirming these results with large sample groups, HER-2 codon 655 SNP and/or c-erbB-2 overexpression may also be used as a poor prognostic indicator for gastric carcinomas.
文摘In this editorial,the roles of protein tyrosine phosphatase nonreceptor 2(PTPN2)in oncogenic transformation and tumor behavior and its potential as a therapeutic target in the context of gastrointestinal(GI)cancers are presented with respect to the article by Li et al published in ninth issue of the World Journal of Gastrointestinal Oncology.PTPN2 is a member of the protein tyrosine phosphatase family of signaling proteins that play crucial roles in the regulation of inflammation and immunity.Accordingly,early findings highlighted the contribution of PTPN2 to the pathogenesis of inflammatory and autoimmune disorders related to its dysfunction.On the other hand,recent studies have indicated that PTPN2 has many different roles in different cancer types,which is associated with the complexity of its regulatory network.PTPN2 dephosphorylates and inactivates EGFR,SRC family kinases,JAK1 and JAK3,and STAT1,STAT3,and STAT5 in cell type-and context-dependent manners,which indicates that PTPN2 can perform either prooncogenic or anti-oncogenic functions depending on the tumor subtype.While PTPN2 has been suggested as a potential therapeutic target in cancer treatment,to the best of ourknowledge,no clear treatment protocol has referred to PTPN2.Although there are only few studies that investigated PTPN2 expression in the GI system cancers,which is a potential limitation,the association of this protein with tumor behavior and the influence of PTPN2 on many therapy-related signaling pathways emphasize that PTPN2 could serve as a new molecular biomarker to predict tumor behavior and as a target for therapeutic intervention against GI cancers.In conclusion,more studies should be performed to better understand the prognostic and therapeutic potential of PTPN2 in GI tumors,especially in tumors resistant to therapy.
基金The study was approved by the ethics committee of Southwest Hospital,the First Affiliated Hospital of Army Medical University of Chinese People's Liberation Army(No.KY2024007).
文摘BACKGROUND Serum retinol-binding protein(RBP)is the primary transport protein of circulating vitamin A.RBP has a crucial role in maintaining nutrient metabolism and physiologic homeostasis.Several studies have indicated that serum RBP participates in the progression of diabetes and diabetes-related complications.However,the impact of serum RBP on lower limb atherosclerosis has not been determined in individuals with type 2 diabetes mellitus(T2DM).AIM To determine the association between serum RBP and lower limb atherosclerosis in individuals with T2DM.METHODS This retrospective study enrolled 4428 eligible T2DM patients and divided the patients into non-lower limb atherosclerosis(n=1913)and lower limb atherosclerosis groups(n=2515)based on lower limb arterial ultrasonography results.At hospital admission,baseline serum RBP levels were assessed,and all subjects were categorized into three groups(Q1-Q3)based on RBP tertiles.Logistic regression,restricted cubic spline regression,subgroup analysis,and machine learning were used to assess the association between RBP levels and lower limb atherosclerosis risk.RESULTS Among 4428 individuals with T2DM,2515(56.80%)had lower limb atherosclerosis.Logistic analysis showed that lower limb atherosclerosis risk increased by 1%for every 1 unit rise in serum RBP level(odds ratio=1.01,95%confidence interval:1.00-1.02,P=0.004).Patients in the highest tertile group(Q3)had a higher lower limb atherosclerosis risk compared to the lowest tertile group(Q1)(odds ratio=1.36,95%confidence interval:1.12-1.67,P=0.002).The lower limb atherosclerosis risk gradually increased with an increase in RBP tertile(P for trend=0.005).Restricted cubic spline analysis indicated a linear correlation between serum RBP levels and lower limb atherosclerosis risk(non-linear P<0.05).Machine learning demonstrated the significance and diagnostic value of serum RBP in predicting lower limb atherosclerosis risk.CONCLUSION Elevated serum RBP levels correlate with an increased lower limb atherosclerosis risk in individuals with T2DM.
文摘BACKGROUND Unraveling the pathogenesis of colorectal cancer(CRC)can aid in developing prevention and treatment strategies.Aurora kinase A(AURKA)is a key participant in mitotic control and interacts with its co-activator,the targeting protein for Xklp2(TPX2)microtubule nucleation factor.AURKA is associated with poor clinical outcomes and high risks of CRC recurrence.AURKA/TPX2 co-overexpression in cancer may contribute to tumorigenesis.Despite its pivotal role in CRC development and progression,the action mechanism of AURKA remains unclear.Further research is needed to explore the complex interplay between AURKA and TPX2 and to develop effective targeted treatments for patients with CRC.AIM To compare effects of AURKA and TPX2 and their combined knockdown on CRC cells.METHODS We evaluated three CRC gene datasets about CRC(GSE32323,GSE25071,and GSE21510).Potential hub genes associated with CRC onset were identified using the Venn,search tool for the retrieval of interacting genes,and KOBAS platforms,with AURKA and TPX2 emerging as significant factors.Subsequently,cell models with knockdown of AURKA,TPX2,or both were constructed using SW480 and LOVO cells.Quantitative real-time polymerase chain reaction,western blotting,cell counting kit-8,cell cloning assays,flow cytometry,and Transwell assays were used.RESULTS Forty-three highly expressed genes and 39 poorly expressed genes overlapped in cancer tissues compared to controls from three datasets.In the protein-protein interaction network of highly expressed genes,AURKA was one of key genes.Its combined score with TPX2 was 0.999,and their co-expression score was 0.846.In CRC cells,knockdown of AURKA,TPX2,or both reduced cell viability and colony number,while blocking G0/G1 phase and enhancing cell apoptosis.Additionally,they were weakened cell proliferation and migration abilities.Furthermore,the expression levels of B-cell lymphoma-2-Associated X,caspase 3,and tumor protein P53,and E-cadherin increased with a decrease in B-cell lymphoma-2,N-cadherin,and vimentin proteins.These effects were amplified when both AURKA and TPX2 were concurrently downregulated.CONCLUSION Combined knockdown of AURKA and TPX2 was effective in suppressing the malignant phenotype in CRC.Coinhibition of gene expression is a potential developmental direction for CRC treatment.
基金This work was supported by a grant from Zhejiang Medical and Health Research Foundation (No. 2000A017).
文摘Objective: To investigate the correlation between c-erbB-2 and multidrug resistance (MDR) and its clinical significance, Methods: Immunohistochemistry stain was used to examine the expression of c-erbB-2 and flow cytometry was used to detect the expression of P-glycoprotein (P-gp) in samples from 46 patients with esophageal carcinoma. Results: The positive expression rate of c-erbB-2 was 26.1% (12/46) in the 46 cases of esophageal carcinoma, of which 4 cases being low expression and 8 cases mediumhigh expression. The positive expression rate of P-gp was 60.9% (28/46) in the 46 cases of esophageal carcinoma, of which 6 cases being low expression, 13 cases medium expression and 9 cases high expression. Comparing c-erbB-2 with P-gp expression in different lymph node metastasis statuses showed that there was significant difference (P〈0.01) between P-gp expressions with lymph node metastasis (31.09%±5.33%) and without lymph node metastasis (8.04%±3.03%) when c-erbB-2 expression was positive. Comparing c-erbB-2 with P-gp expression in different TNM stages of esophageal carcinoma showed that there was significant difference (P〈0.01) between P-gp expressions in HI Ⅳ stage (33.68%±5.51%)and in Ⅱ stage patients (9.30%±2.78%) when c-erbB-2 expression was positive. The tumor's size and differentiation degree were not related to c-erbB-2 and P-gp expression. Conclusion: The high level of P-gp expression was related to the positive expression of c-erbB-2 with the lymph node metastasis in clinical Ⅲ-Ⅳ stage patients of esophageal carcinoma, suggesting that the double positive might lead to a poor prognosis. However, when the c-erbB-2 expression was negative, the lymph node metastasis and clinical staging were not related to the P-gp expression in esophageal carcinoma patients.
基金supported by the National Key R&D Program of China (2022YFE0196200)the National Natural Science Foundation of China–Deutsche Forschungsgemeinschaft of Germany (31761133021)+3 种基金the National Natural Science Foundation of China (31970469 and 31701794)the earmarked fund for Modern Agro-industry Technology Research System, China (2023CYJSTX01-20)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi, China (2017104)the Fund for Shanxi “1331 Project”, China
文摘Low-density lipoprotein receptor-related protein 2(LRP2)is a multifunctional endocytic receptor expressed in epithelial cells.In mammals,it acts as an endocytic receptor that mediates the cellular uptake of cholesterol-containing apolipoproteins to maintain lipid homeostasis.However,little is known about the role of LRP2 in lipid homeostasis in insects.In the present study,we investigated the function of LRP2 in the migratory locust Locusta migratoria(LmLRP2).The mRNA of LmLRP2 is widely distributed in various tissues,including integument,wing pads,foregut,midgut,hindgut,Malpighian tubules and fat body,and the amounts of LmLRP2 transcripts decreased gradually in the early stages and then increased in the late stages before ecdysis during the nymphal developmental stage.Fluorescence immunohistochemistry revealed that the LmLRP2 protein is mainly located in cellular membranes of the midgut and hindgut.Using RNAi to silence LmLRP2 caused molting defects in nymphs(more than 60%),and the neutral lipid was found to accumulate in the midgut and surface of the integument,but not in the fat body,of dsLmLRP2-treated nymphs.The results of a lipidomics analysis showed that the main components of lipids(diglyceride and triglyceride)were significantly increased in the midgut,but decreased in the fat body and hemolymph.Furthermore,the content of total triglyceride was significantly increased in the midgut,but markedly decreased in the fat body and hemolymph in dsLmLRP2-injected nymphs.Our results indicate that LmLRP2 is located in the cellular membranes of midgut cells,and is required for lipid export from the midgut to the hemolymphand fat body in locusts.
基金Supported by the National Natural Science Foundation of China,No.81471094 and No.82202743.
文摘BACKGROUND Recently,type 2 diabetic osteoporosis(T2DOP)has become a research hotspot for the complications of diabetes,but the specific mechanism of its occurrence and development remains unknown.Ferroptosis caused by iron overload is con-sidered an important cause of T2DOP.Polycytosine RNA-binding protein 1(PCBP1),an iron ion chaperone,is considered a protector of ferroptosis.AIM To investigate the existence of ferroptosis and specific role of PCBP1 in the development of type 2 diabetes.METHODS A cell counting kit-8 assay was used to detect changes in osteoblast viability under high glucose(HG)and/or ferroptosis inhibitors at different concentrations and times.Transmission electron microscopy was used to examine the morpho-logical changes in the mitochondria of osteoblasts under HG,and western blotting was used to detect the expression levels of PCBP1,ferritin,and the ferroptosis-related protein glutathione peroxidase 4(GPX4).A lentivirus silenced and overex-pressed PCBP1.Western blotting was used to detect the expression levels of the osteoblast functional proteins osteoprotegerin(OPG)and osteocalcin(OCN),whereas flow cytometry was used to detect changes in reactive oxygen species(ROS)levels in each group.RESULTS Under HG,the viability of osteoblasts was considerably decreased,the number of mitochondria undergoing atrophy was considerably increased,PCBP1 and ferritin expression levels were increased,and GPX4 expression was decreased.Western blotting results demonstrated that infection with lentivirus overexpressing PCBP1,increased the expression levels of ferritin,GPX4,OPG,and OCN,compared with the HG group.Flow cytometry results showed a reduction in ROS,and an opposite result was obtained after silencing PCBP1.CONCLUSION PCBP1 may protect osteoblasts and reduce the harm caused by ferroptosis by promoting ferritin expression under a HG environment.Moreover,PCBP1 may be a potential therapeutic target for T2DOP.
文摘Objective: To detect the relations of c-erbB-2 onco-gene protein, epidermal growth factor receptor (EG-FR) and transforming growth factor-β1 (TGF-β1)to the progression or metastasis of pancreatic carci-noma.Methods: Using streptavidinbiotin complex (SABC)method, c-erbB-2 oncongene protein, we examinedimmunohistochemically EGFR and TGF-β1 expres-sions in wax-tissue sections from 10 individuals withnormal pancreas (NP), 13 patients with chronic pan-creatitis (CP) and 36 patients with pancreatic ductaladenocarcinoma (PC).Results: The positive expression rates of c-cerbB-2oncogene protein, EGFR and TGF-β1 in the NP, CPand PC groups were 0, 0, 10%; 7.7%, 7.7%,7.7%; and 41.7%, 50.0%, 44.4%, respectively.The positive expression rates of the three specific pro-teins increased more significantly in the PC groupthan in the NP and CP groups (P【0.05). The indi-vidual expression of c-erbB-2, EGFR and TGF-β1was not related to the age and sex of the patients aswell as the site, size and histopathological grade oftumors (P】0.05), but to the clinical stage of tumors(P【0.01). The coexpression rate of the three pro-teins was 27.8 % (10/36). This coexpression in thePC group was correlated with the histopathologicalgrades and clinical stages of tumors (P【0.01).Conclusion: Detection of c-erbB-2 oncogene protein,EGFR, and TGF-β1 expressions in pancreatic tissueis helpful to judge the malignancy, progression, andmetastasis of PC.
基金funded by the National Key Research and Development Program of China(2023YFF1104502)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2022QNRC001).
文摘As the global demographic shifts toward an aging population,understanding the efficiency of protein uti-lization in older adults becomes crucial.Our study explores the intricate relationship between protein intake and aging,with a focus on precision nutrition for older people.Through a meta-analysis,we con-firm a decline in protein-utilization capacity in older individuals and examine the different contributions of plant and animal protein.In experiments involving mice of different ages,older mice exhibited decreases in the biological utilization of four proteins(casein,beef protein,soy protein,and gluten),par-ticularly casein.In subsequent research,casein was studied as a key protein.A decline in gastric digestion function was observed through peptidomics and the examination of pepsin levels using casein.Nevertheless,this decline did not significantly affect the overall protein digestion during the aging pro-cess.The combined application of targeted amino acid metabolomics identified abnormal absorption of amino acids as the underlying cause of decreased protein utilization during aging,particularly emphasiz-ing a reduction in branched-chain amino acids(BCAAs)in older mice.Delving deeper into the proteomics of the intestinal protein digestion and absorption pathway,a reduction of over 60%in large neutral amino acid transporter 2(LAT2)protein expression was observed in both older humans and aged mice.The reduction in LAT2 protein was found to be a key factor influencing the diminished BCAA availability.Overall,our study establishes the significance of amino acid absorption through LAT2 in protein utiliza-tion during aging and offers a new theoretical foundation for improving protein utilization in the older adults.
基金supported by the Major Project of Science and Technology Department of Yunnan Province (202002AA100005 and 202102AE090027-2)the Project of Yunnan Province Food and Drug Homologous Resources Functional Food Innovation Team (A3032023057)+2 种基金the YEFICRC project of Yunnan provincial key programs (2019ZG009)Yunnan Province Ten Thousand Plan Industrial Technology Talents project (YNWR-CYJS-2020-010)the Yunnan Provincial Department of Science and Technology Agricultural Joint Special Project (202101BD070001-120)。
文摘Walnut dreg protein hydrolysates(WDPHs)exhibit a variety of biological activities,however,the cyclooxygenase-2(COX-2)inhibitory peptide of WDPHs remain unclear.The aim of this study was to rapidly screen for such peptides in WDPHs through a combination of in silico and in vitro analysis.In total,1262 peptide sequences were observed by nano liquid chromatography/tandem mass spectrometry(nano LC-MS/MS)and 4 novel COX-2 inhibitory peptides(AGFP,FPGA,LFPD,and VGFP)were identified.Enzyme kinetic data indicated that AGFP,FPGA,and LFPD displayed mixed-type COX-2 inhibition,whereas VGFP was a non-competitive inhibitor.This is mainly because the peptides form hydrogen bonds and hydrophobic interactions with residues in the COX-2 active site.These results demonstrate that computer analysis combined with in vitro evaluation allows for rapid screening of COX-2 inhibitory peptides in walnut protein dregs.
基金Supported by General Program of National Natural Science Foundation of China,No.81770197Scientific and Technological Research Major Program of Chongqing Municipal Education Commission,No.KJZD-M202312802+1 种基金Chongqing Natural Science Foundation of China,No.CSTB2022NSCQ-MSX0190,No.CSTB2022NSCQ-MSX0176,and No.cstc2020jcyj-msxmX0051Xinqiao Young Postdoc Talent Incubation Program,No.2022YQB098.
文摘BACKGROUND Thrombocytopenia 2,an autosomal dominant inherited disease characterized by moderate thrombocytopenia,predisposition to myeloid malignancies and normal platelet size and function,can be caused by 5’-untranslated region(UTR)point mutations in ankyrin repeat domain containing 26(ANKRD26).Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1)have been identified as negative regulators of ANKRD26.However,the positive regulators of ANKRD26 are still unknown.AIM To prove the positive regulatory effect of GATA binding protein 2(GATA2)on ANKRD26 transcription.METHODS Human induced pluripotent stem cells derived from bone marrow(hiPSC-BM)INTRODUCTION Ankyrin repeat domain containing protein 26(ANKRD26)acts as a regulator of adipogenesis and is involved in the regulation of feeding behavior[1-3].The ANKRD26 gene is located on chromosome 10 and shares regions of homology with the primate-specific gene family POTE.According to the Human Protein Atlas database,the ANKRD26 protein is localized to the Golgi apparatus and vesicles,and its expression can be detected in nearly all human tissues[4].Moreover,UniProt annotation revealed that ANKRD26 is localized in the centrosome and contains coiled-coil domains formed by spectrin helices and ankyrin repeats[5,6].The most common disease related to ANKRD26 is thrombocytopenia 2(THC2),which is a rare autosomal dominant inherited disease characterized by lifelong mild-to-moderate thrombocytopenia and mild bleeding[7-9].Caused by the variants in the 5’-untranslated region(UTR)of ANKRD26,THC2 is defined by a decrease in the number of platelets in circulating blood and results in increased bleeding and decreased clotting ability[8,10].Due to the point mutations that occur in the 5’-UTR of ANKRD26,its negative transcription factors(TFs),Runt related transcription factor 1(RUNX1)and friend leukemia integration 1(FLI1),lose their repression effect[11].The persistent expression of ANKRD26 increases the activity of the mitogen activated protein kinase and extracellular signal regulated kinase 1/2 signaling pathways,which are potentially involved in the regulation of thrombopoietin-dependent signaling and further impair proplatelet formation by megakaryocytes(MKs)[11].However,the positive regulators of ANKRD26,which might be associated with THC2 pathology,are still unknown.
基金the Zhejiang Medical and Health Science Foundation (No. 2005A09)
文摘Objective: To understand the relationship between C-erbB-2 and multidrug resistance (MDR) as well as its clinical significance. Methods: P-gp level was detected by flow cytometry and simultaneously to examine the C-erbB-2 expression level by immunohistochemistry assay in the operating samples. Their relationship was analyzed from 59 cases with gastric carcinoma. Results: The P-gp positive expression was 38/59 (64.4%) cases with gastric carcinoma. The C-erbB-2 positive expression was 21/59 (35.6%) cases with gastric carcinoma. From the analysis of the P-gp and C-erbB-2 relationship, which was involving, range in the gastric carcinoma, that involving two or three sites were more than the site one, in the cases with C-erbB-2 negative. Compared this two groups, there was a significant difference (P = 0.026). When the C-erbB-2 was positive, the P-gp expression had a significant difference (P = 0.04) in comparing the Ⅲ-Ⅳ stage (lymph node metastasis) with Ⅰ-Ⅱ stage (without lymph node metastasis). The tumor's size, differentiation degree, ages and sex were not related to the C-erbB- 2 and P-gp expression. Conclusion: High level of P-gp expression was related to the C-erbB-2 positive expression in clinical Ⅲ-Ⅳ stage patient with gastric carcinoma (lymph node metastasis). It suggested that the double positive patient might be a poor prognosis. However, when the C-erbB-2 was negative expression, the clinical staging (with lymph node metastasis) was not related to the P-gp expression in gastric carcinoma patients.
基金supported by a National Research Foundation of Korea(NRF)grant funded by the Korean Government,Ministry of Science and ICT(MSIT)(2016R1C1B102207,2022R1A2C1004141 and 2022R1A2C-1091712)the National R&D Program for Cancer Control through the National Cancer Center(NCC)funded by the Ministry of Health&Welfare,Republic of Korea(HA22C0053000022).
文摘Pancreatic ductal adenocarcinoma(PDAC)is one of the most aggressive solid malignancies.A specific mechanism of its metastasis has not been established.In this study,we investigated whether Neural Wiskott-Aldrich syndrome protein(N-WASP)plays a role in distant metastasis of PDAC.We found that N-WASP is markedly expressed in clinical patients with PDAC.Clinical analysis showed a notably more distant metastatic pattern in the N-WASP-high group compared to the N-WASP-low group.N-WASP was noted to be a novel mediator of epithelialmesenchymal transition(EMT)via gene expression profile studies.Knockdown of N-WASP in pancreatic cancer cells significantly inhibited cell invasion,migration,and EMT.We also observed positive association of lysyl oxidase-like 2(LOXL2)and focal adhesion kinase(FAK)with the N-WASP-mediated response,wherein EMT and invadopodia function were modulated.Both N-WASP and LOXL2 depletion significantly reduced the incidence of liver and lung metastatic lesions in orthotopic mouse models of pancreatic cancer.These results elucidate a novel role for N-WASP signaling associated with LOXL2 in EMT and invadopodia function,with respect to regulation of intercellular communication in tumor cells for promoting pancreatic cancer metastasis.These findings may aid in the development of therapeutic strategies against pancreatic cancer.