Blocking NF-kB nuclear translocation leads to p53-related autophagy activation and cell apoptosis

AIM: To investigate the anti-tumor effects of nuclear factor-κB (NF-κB) inhibitor SN50 and related mechanisms of SGC7901 human gastric carcinoma cells. METHODS: MTT assay was used to determine the cytotoxic effects of SN50 in gastric cancer cell line SGC7901. Hoechst 33258 staining was used to detect apoptosis morphological changes after SN50 treatment. Activation of autophagy was monitored with monodansylcadaverine (MDC) staining after SN50 treatment.Immunofluorescence staining was used to detect the expression of light chain 3 (LC3). Mitochondrial membrane potential was measured using the fluorescent probe JC-1. Western blotting analysis were used to determine the expression of proteins involved in apoptosis and autophagy including p53, p53 upregulated modulator of apoptosis (PUMA), damage-regulated autophagy modulator (DRAM), LC3 and Beclin 1. We detected the effects of p53-mediated autophagy activation on the apoptosis of SGC7901 cells with the p53 inhibitor pifithrin-α. RESULTS: The viability of SGC7901 cells was inhibited after SN50 treatment. Inductions in the expression of apoptotic protein p53 and PUMA as well as autophagic protein DRAM, LC3 and Beclin 1 were detected with Western blotting analysis. SN50-treated cells exhibited punctuate microtubule-associated protein 1 LC3 in immunoreactivity and MDC-labeled vesicles increased after treatment of SN50 by MDC staining. Collapse of mitochondrial membrane potential Δψ were detected for 6 to 24 h after SN50 treatment. SN50-induced increases in PUMA, DRAM, LC3 and Beclin 1 and cell death were blocked by the p53 specific inhibitor pifithrin-α. CONCLUSION: The anti-tumor activity of NF-κB inhibitors is associated with p53-mediated activation of autophagy.

Dual protective role of HO-1 in transplanted liver grafts:A review of experimental and clinical studies

Liver transplantation is considered as the most effective treatment for end-stage liver disease.However,serious complications still exist,particularly in two aspects:ischemia and subsequent reperfusion of the liver,causing postoperative hepatic dysfunction and even failure;and acute and chronic graft rejections,affecting the allograft survival.Heme oxygenase(HO),a stressresponse protein,is believed to exert a protective function on both the development of ischemia-reperfusion injury(IRI) and graft rejection.In this review of current researches on allograft protection,we focused on the HO-1.We conjecture that HO-1 may link these two main factors affecting the prognosis of liver transplantations.In this review,the following aspects were emphasized:the basic biological functions of HO-1,itsroles in IRI and allograft rejection,as well as methods to induce HO-1 and the prospects of a therapeutic application of HO-1 in liver transplantation.

Proteasome inhibitor ameliorates severe acute pancreatitis and associated lung injury of rats

AIM: To observe the effect of proteasome inhibitor MG-132 on severe acute pancreatitis (SAP) and associated lung injury of rats. METHODS: Male adult SD rats were randomly divided into SAP group, sham-operation group, and MG-132 treatment group. A model of SAP was established by injection of 5% sodium taurocholate into the biliary- pancreatic duct of rats. The MG-132 group was pretreated with 10 mg/kg MG-132 intraperitoneally (ip) 30 min before the induction of pancreatitis. The changes in serum amylase, myeloperoxidase (MPO) activity of pancreatic and pulmonary tissue were measured. The TNF-α level in pancreatic cytosolic fractions was assayed with an enzyme-linked immunosorbent assay (ELISA) kit. Meanwhile, the pathological changes in both pancreatic and pulmonary tissues were also observed. RESULTS: MG-132 significantly decreased serum amylase, pancreatic weight/body ratio, pancreatic TNF-α level, pancreatic and pulmonary MPO activity (P < 0.05). Histopathological examinations revealed that pancreatic and pulmonary samples from rats pretreated with MG-132 demonstrated milder edema, cellular damage, and inflammatory activity (P < 0.05). CONCLUSION: The proteasome inhibitor MG-132 shows a protective effect on severe acute pancreatitis and associated lung injury of rats.

Inhibition of pancreatic carcinoma cell growth in vitro by DPC4 gene transfection

AIM: To detect the expression of DPC4 in malignant and non-malignant specimens of human pancreas,and observe the inhibition of retroviral pLXSN containing DPC4 on pancreatic carcinoma cells in vitro.METHODS: The expression of DPC4 was determined in 40 pancreatic adenocarcinoma and 36 non-malignant pancreatic specimens by reverse-transcriptase polymerase chain reaction (RT-PCR) and immunohisto-chemistry.Furthermore,we constructed retroviral vectors containing DPC4,which then infected the pancreatic carcinoma cell line BxPC-3.Cell growth in vitro after being infected was observed,and the vascular endothelial growth factor (VEGF) mRNA level in the daughter cells was determined by semi-quantitative PCR assay.RESULTS: The RT-PCR assay showed a positive rate of DPC4 mRNA in 100% (36/36) of normal specimens,compared to 40% (16/40) in adenocarcinoma specimens.The regional and intense positive cases of DPC4 expression in adenocarcinoma detected by immunohistochemistry were 10 and four,whereas it was all positive expression in normal tissues.There was a significant difference of DPC4 expression between them.The stable expression of DPC4 in the pancreatic carcinoma cells BxPC-3 could be resumed by retroviral vector pLXSN transfection,and could inhibit cell growth in vitro.Rather,DPC4 could decrease VEGF mRNA transcription levels.CONCLUSION: The deletion of DPC4 expression in pancreatic carcinoma suggests that loss of DPC4 may be involved in the development of pancreatic carcinoma.The retroviral vector pLXSN containing DPC4 can inhibit the proliferation of pancreatic carcinoma cells,and down-regulate the level of VEGF.

Spontaneous perforation of an intramural rectal hematoma:Report of a case

Spontaneous hematomas are rare and most occur secondary to hematologic disorders or during anticoagulant therapy.Most spontaneous hematomas occur above the sigmoid colon,and rarely in the rectum.Herein we present the case of a patient with a spontaneous perforating hematoma of the rectum who presented with severe abdominal pain after a bloody stool.The hemoglobin level decreased by 33 g/L within 20 h.An abdominal sonogram showed a hydrops in the lower abdomen with a maximum depth of 7.0 cm.A hematoma,8 cm × 6 cm × 5 cm in size,was noted intra-operatively in the rectosigmoid junction,with a 1.5-cm perforation in the hematoma and active hemorrhage.Thus,a partial rectectomy and sigmoidostomy were performed.Three months later,a second operative procedure to re-establish intestinal continuity was performed.The patient is in good condition 12 mo after the last surgery.In addition to this case,the causes of spontaneous perforating hematomas and the treatment are discussed.

Galactosylated chitosan/5-fluorouracil nanoparticles inhibit mouse hepatic cancer growth and its side effects

AIM:To observe the curative effect of galactosylated chitosan(GC)/5-fluorouracil(5-FU) nanoparticles in liver caner mice and its side effects.METHODS:The GC/5-FU nanoparticle is a nanomaterial made by coupling GC and 5-FU.The release experiment was performed in vitro.The orthotropic liver cancer mouse models were established and divided into control,GC,5-FU and GC/5-FU groups.Mice in the control and GC group received an intravenous injection of 200 L saline and GC,respectively.Mice in the 5-FU and GC/5-FU groups received 200 L(containing 0.371 mg 5-FU) 5-FU and GC/5-FU,respectively.The tumor weight and survival time were observed.The cell cycle and apoptosis in tumor tissues were monitored by flow cytometry.The expression of p53,Bax,Bcl-2,caspase-3 and poly adenosine 50-diphosphate-ribose polymerase 1(PARP-1) was detected by immunohistochemistry,reverse transcription-polymerase chain reaction and Western blot.The serum blood biochemical parameters and cytotoxic activity of natural killer(NK) cell and cytotoxicity T lymphocyte(CTL) were measured.RESULTS:The GC/5-FU nanoparticle is a sustained release system.The drug loading was 6.12% ± 1.36%,the encapsulation efficiency was 81.82% ± 5.32%,and the Zeta potential was 10.34 ± 1.43 mV.The tumor weight in the GC/5-FU group(0.4361 ± 0.1153 g vs 1.5801 ± 0.2821 g,P < 0.001) and the 5-FU(0.7932 ± 0.1283 g vs 1.5801 ± 0.2821 g,P < 0.001) was significantly lower than that in the control group;GC/5FU treatment can significantly lower the tumor weight(0.4361 ± 0.1153 g vs 0.7932 ± 0.1283 g,P < 0.001),and the longest median survival time was seen in the GC/5-FU group,compared with the control(12 d vs 30 d,P < 0.001),GC(13 d vs 30 d,P < 0.001) and 5-FU groups(17 d vs 30 d,P < 0.001).Flow cytometry revealed that compared with the control,GC/5FU caused a higher rate of G0-G1 arrest(52.79% ± 13.42% vs 23.92% ± 9.09%,P = 0.014) and apoptosis(2.55% ± 1.10% vs 11.13% ± 11.73%,P < 0.001) in hepatic cancer cells.Analysis of the apoptosis pathways showed that GC/5-FU upregulated the expression of p53 at both the protein and the mRNA levels,which in turn lowered the ratio of Bcl-2/Bax expression;this led to the release of cytochrome C into the cytosol from the mitochondria and the subsequent activation of caspase-3.Upregulation of caspase-3 expression decreased the PARP-1 at both the mRNA and the protein levels,which contributed to apoptosis.5-FU increased the levels of aspartate aminotransferase and alanine aminotransferase,and decreased the numbers of platelet,white blood cell and lymphocyte and cytotoxic activities of CTL and NK cells,however,there were no such side effects in the GC/5-FU group.CONCLUSION:GC/5-FU nanoparticles can significantly inhibit the growth of liver cancer in mice via the p53 apoptosis pathway,and relieve the side effects and immunosuppression of 5-FU.

Prognostic factors of primary gastrointestinal stromal tumors： a cohort study based on high-volume centers

Objective： We aimed to evaluate the clinicopathologic characteristics, immunohistochemical expression and prognostic factors of patients with primary gastrointestinal stromal tumors（GISTs）.Methods： Data from 2,570 consecutive GIST patients from four medical centers in China（January2001–December 2015） were reviewed. Survival curves were constructed by the Kaplan-Meier method, and Cox regression models were used to identify independent prognostic factors.Results： Of the included patients, 1,375（53.5%） were male, and the patient age range was 18 to 95（median, 58）years. The tumors were mostly found in the stomach（64.5%）, small intestine（25.1%） and colorectal region（5.1%）.At the time of diagnosis, the median tumor size was 4.0（range： 0.1–55.0） cm, and the median mitotic index per 50 high power fields（HPFs） was 3（range： 0–254）. Of the 2,168 resected patients, 2,009（92.7%） received curative resection. According to the modified National Institutes of Health（NIH） classification, 21.9%, 28.9%, 14.1% and35.1% were very low-, low-, intermediate-and high-risk tumors, respectively. The rate of positivity was 96.4% for c-Kit, 87.1% for CD34, 96.9% for delay of germination 1（DOG-1）, 8.0% for S-100, 31.0% for smooth muscle actin（SMA） and 5.1% for desmin. However, the prognostic value of each was limited. Multivariate analysis showed that age, tumor size, mitotic index, tumor site, occurrence of curative resection and postoperative imatinib were independent prognostic factors. Furthermore, we found that high-risk patients benefited significantly from postoperative imatinib（P〈0.001）, whereas intermediate-risk patients did not（P=0.954）.Conclusions： Age, tumor size, mitotic index, tumor site, occurrence of curative resection and postoperative imatinib were independent prognostic factors in patients with GISTs. Moreover, determining whether intermediate-risk patients can benefit from adjuvant imatinib would be of considerable interest in future studies.

Construction of humanized carcinoembryonic antigen specific single chain variable fragment and mitomycin conjugate

AIM: To construct a new target-oriented conjugate of humanized carcinoembryonic antigen (CEA) specific single chain variable fragment (scFv) and mitomycin (MMC) against colorectal cancer, and to investigate its influence on the growth and apoptosis of colorectal cancer cells. METHODS: The primer was designed according to the gene sequence described in reference 16, which respectively contains restriction enzyme cleavage sites BamHⅠ and EcoRⅠ in its upstream and downstream. PCR was performed with the plasmid as template containing genes of humanized anti-CEA scFv. The product was digested by Bam HⅠ and Eco RⅠ, and connected to an expression vector which also has the restriction enzyme cleavage sites Bam HⅠ and Eco R. Expression of the reaction was induced by isopropy-β -D-thiogalactoside (IPTG). Then the expression product was covalently coupled with MMC by dextran T-40. The immunoreactivity of the conjugate against colorectal cancer cells as well as CEA was measured by enzyme linked immunosorbent assay (ELISA). The inhibiting ratio of conjugate on the growth of colorectal cancer cells was also measured by ELISA. The effect of conjugate on the apoptosis of colorectal cancer cells was determined by flow cytometry (FCM). RESULTS: Restriction endonuclease cleavage and gene sequencing confirmed that the expression vector was successfully constructed. Sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-PAGE) confirmed that this vector correctly expressed the fusion protein. ELISA confirmed that the conjugate had quite a strong immunoreactivity against colorectal cancer cells and CEA. The conjugate had inhibitory effects on colorectal cancer cells in a concentration-dependent manner and could induce apoptosis of colorectal cancer cells in a concentration-dependent manner.CONCLUSION: The CEA-scFv-MMC conjugate can be successfully constructed and is able to inhibit the growth and induce apoptosis of colorectal cancer cells.

Tumor suppress genes screening analysis on 4q in sporadic colorectal carcinoma

AIM: To search candidate tumor suppressor genes (TSGs) on chromosome 4q through detecting high loss of heterozygosity (LOH) regions in sporadic colorectal carcinoma in Chinese patients. METHODS: Thirteen fluorescent labeled polymorphic microsatellite markers were analyzed in 83 cases of colorectal carcinoma and matched normal tissue DNA by polymerase chain reaction (PCR). PCR products were eletrophoresed on an ABI 377 DNA sequencer. Genescan 3.7 and Genotype 3.7 software were used for LOH scanning and analysis. Comparison between LOH frequency and clinicopathological factors were performed by χ2 test. RESULTS: Data were collected on all informative loci. The average LOH frequency on 4q was 28.56%. The D4S2915 locus showed highest LOH frequency (36.17%). Two obvious deletion regions were detected: one between D4S3000 and D4S2915 locus (4q12-21.1), another flanked by D4S407 and D4S2939 locus (4q25-31.1). None case showed complete deletion of 4q, most cases displayed interstitial deletion pattern solely. Furthermore, compared with clinicopathological features, a significant relationship was observed between LOH frequencies on D4S3018locus. In tumors larger than 5 cm in diameter, LOH frequency was significantly higher than tumors that were less than 5 cm (56% vs 13.79%, P = 0.01). On D4S1534 locus, LOH was significantly associated with liver metastasis (80% vs 17.25%, P = 0.012). No relationship was detected on other locus compared with clinicopathologial features. CONCLUSION: By high resolution deletion mapping, two high frequency regions of LOH (4q12-21.1 and 4q25-31.1) were detected, which may contribute to locate TSGs on chromosome 4q involved in carcinogenesis and progression of sporadic colorectal carcinoma.

Are there tumor suppressor genes on chromosome 4p in sporadic colorectal carcinoma?

AIM: To study the candidate tumor suppressor genes (TSG) on chromosome 4p by detecting the high frequency of loss of heterozygosity (LOH) in sporadic colorectal carcinoma in Chinese patients.METHODS: Seven fluorescent labeled polymorphic microsatellite markers were analyzed in 83 cases of colorectal carcinoma and matched normal tissue DNA by PCR. PCR products were eletrophoresed on an ABI 377 DNA sequencer. Genescan 3.7 and Genotype 3.7 software were used for LOH scanning and analysis. The same procedure was performed by the other six microsatellite markers spanning D4S3013 locus to make further detailed deletion mapping. Comparison between LOH frequency and clinicopathological factors was performed by χ2 test.RESULTS: Data were collected from all informative loci. The average LOH frequency on 4p was 24.25%, and 42.3% and 35.62% on D4S405 and D4S3013 locus, respectively. Adjacent markers of D4S3013 displayed a low LOH frequency (< 30%) by detailed deletion mapping. Significant opposite difference was observed between LOH frequency and tumor diameter on D4S412 and D4S1546 locus (0% vs 16.67%, P = 0.041; 54.55% vs 11.11%, P = 0.034, respectively). On D4S403 locus, LOH was significantly associated with tumor gross pattern (11.11%, 0, 33.33%, P = 0.030). No relationship was detected on other loci compared with clinicopathologial features.CONCLUSION: By deletion mapping, two obvious high frequency LOH regions spanning D4S3013 (4p15.2) and D4S405 (4p14) locus are detected. Candidate TSG, which is involved in carcinogenesis and progression of sporadic colorectal carcinoma on chromosome 4p, may be located between D4S3017 and D4S2933 (about 1.7 cm).

Total body irradiation of donors can alter the course of tolerance and induce acute rejection in a spontaneous tolerance rat liver transplantation model

Liver transplantation is an established therapy for end-stage liver diseases. Graft rejection occurs unless the recipient receives immunosuppression after transplantation. This study aimed to explore the mechanism of acute rejection of liver allografts in rats pre-treated with total body irradiation to eliminate passenger lymphocytes and to define the role of CD4 + CD25 + regulatory T cells in the induction of immunotolerance in the recipient. Male Lewis rats were used as donors and male DA rats were recipients. Rats were randomly assigned to the following four groups: control group, homogeneity liver transplantation group, idio-immunotolerance group and acute rejection group. After transplantation, the survival time of each group, serum alanine aminotransferase, total bilirubin levels, number of Foxp3 + CD4 + CD25 + regulatory T cells, expression of glucocorticoid-induced tumor necrosis factor receptor on T cell subgroups, histopathology of the hepatic graft and spleen cytotoxic T lymphocyte lytic activity were measured. In the acute rejection group, where donors were preconditioned with total body irradiation before liver transplantation, all recipients died between day 17 and day 21. On day 14, serum alanine aminotransferase increased signifi- cantly to (459.2±76.9) U L -1 , total bilirubin increased to (124.1±33.7) μmol L -1 (P<0.05) and the ratio of Foxp3 + CD4 + CD25 + regulatory T cells decreased significantly to 1.50%±0.50% (P<0.05) compared with the other groups. Analysis of the T cell subpopulations in the acute rejection group varied from the other groups. Histological analysis showed typical changes of acute rejection in the acute rejection group only. Preconditioning of the donors with total body irradiation eliminated passenger lymphocytes of the liver graft, and thus affected the course of tolerance and induced acute rejection after liver transplantation.

The current surgical treatment of pancreatic cancer in China: a national wide cross-sectional study

Objective: The aim of this study is to investigate the current status of pancreatic cancer patients undoing surgical treatment in China and to find ways to improve the survival of these patients in the future. Methods: This study is a national, multicenter, cross-sectional study in China. Information regarding pancreatic cancer patients undergoing surgical treatment from 34 high-volume tertiary IIIA level hospitals was collected and analyzed from the March 1, 2016 to the February 28, 2017. Results: In total, 2200 pancreatic cancer patients were enrolled from 34 tertiary IIIA level hospitals in 16 provinces across China. The male-to-female ratio was 1.5. More than 80% of the patients were between 50 and 70 years old. The top 4 symptoms were epigastric discomfort, abdominal pain, jaundice, and weight loss. Carbohydrate antigen 19-9 and carcinoembryonic antigen were elevated in 70.9% and 27.1% of patients, respectively. A multidisciplinary team (MDT) discussion was carried out for 35.0% of patients before surgery. The proportion of minimally invasive pancreatic surgeries was approximately 20%. A total of 83.4% of the operations achieved R0 resection, and the incidence of grade 3/4 postoperative complications was 7.7%. Only 13.4% of the patients received postoperative adjuvant chemotherapy. The percentage of pathological stage I tumors was only 24.5%. Conclusion: The majority of pancreatic cancer patients undergoing surgical resection in China are in an advanced stage. The MDT consultations for pancreatic cancer have not been widely carried out. R0 resection has been achieved in most cases, with relatively low incidence of serious complications, but minimally invasive pancreatic surgery should be further promoted. The application of postoperative chemotherapy remains low. This national, multicentre, cross-sectional study comprehensively presents the current status of pancreatic cancer patients undergoing surgical treatment and shows the road to improve survival of these patients in the future.