Silencing Bmi-1 enhances the senescence and decreases the metastasis of human gastric cancer cells

AIM:To evaluate the impact of Bmi-1 on cell senescence and metastasis of human gastric cancer cell line BGC823.METHODS:Two pairs of complementary small hairpin RNA(shRNA)oligonucleotides targeting the Bmi-1gene were designed,synthesized,annealed and cloned into the pRNAT-U6.2 vector.After DNA sequencing to verify the correct insertion of the shRNA sequences,the recombinant plasmids were transfected into BGC823 cells.The expression of Bmi-1 mRNA and protein was examined by reverse transcription-polymerase chain reaction(RT-PCR)and Western blotting.The effects of Bmi-1 knockdown on cell senescence and metastasis were determined by theβ-Gal activity assay and Boyden chamber assay,respectively.RESULTS:The double-stranded oligonucleotide fragments of Bmi-1 short interfering RNA(siRNA)cloned into pRNAT-U6.2 vector conformed to the inserted sequence.RT-PCR and Western blotting indicated that the expression levels of Bmi-1 gene mRNA and protein were markedly decreased in transfected BGC823 cells with pRNAT-U6.2-si1104 and pRNATU6.2-si1356,especially in transfected BGC823 cells with pRNAT-U6.2-si1104,compared with two control groups(empty vector and blank group).In particular,Bmi-1 protein expression was almost completely abolished in cells transfected with the recombinant vector harboring shRNA targeting the sequence GGAGGAGGTGAATGATAAA(nt1104-1122).Compared with untransfected cells and cells transfected with the empty vector,the mean percentage of senescent cells increased and the number of cells passing through the Matrigel decreased in cells transfected with the recombinant vectors.CONCLUSION:Silencing Bmi-1 by RNA interference can increase the senescent cell rate and effectively reduce the metastasis of gastric cancer cells.

Immune-related long noncoding RNA zinc finger protein 710-AS1-201 promotes the metastasis and invasion of gastric cancer cells

BACKGROUND Gastric cancer(GC)is a prevalent malignant tumor of the gastrointestinal system.ZNF710 is a transcription factor(TF),and zinc finger protein 710(ZNF710)-AS1-201 is an immune-related long noncoding RNA(lncRNA)that is upregulated in GC cells.AIM To assess the correlation between ZNF710-AS1-201 and immune microenvir-onment features and to investigate the roles of ZNF710-AS1-201 in the invasion and metastasis processes of GC cells.METHODS We obtained data from The Cancer Genome Atlas and Wujin Hospital.We assessed cell growth,migration,invasion,and programmed cell death using cell counting kit-8,EdU,scratch,Transwell,and flow cytometry assays.Quantitative real-time polymerase chain reaction(qRT-PCR)was used to identify the potential downstream targets of ZNF710-AS1-201.RESULTS In GC tissues with low ZNF710-AS1-201 expression,immunoassays detected significant infiltration of various antitumor immune cells,such as memory CD8 T cells and activated CD4 T cells.In the low-expression group,the half-maximal inhibitory concentrations(IC_(50)s)of 5-fluorouracil,cisplatin,gemcitabine,and trametinib were lower,whereas the IC_(50)s of dasatinib and vorinostat were higher.The malignant degree of GC was higher and the stage was later in the high-expression group.Additionally,patients with high expression of ZNF710-AS1-201 had lower overall survival and disease-free survival rates.In vitro,the overexpression of ZNF710-AS1-201 greatly enhanced growth,metastasis,and infiltration while suppressing cell death in HGC-27 cells.In contrast,the reduced expression of ZNF710-AS1-201 greatly hindered cell growth,enhanced apoptosis,and suppressed the metastasis and invasion of MKN-45 cells.The expression changes in ZNF710 were significant,but the corresponding changes in isocitrate dehydrogenase-2,Semaphorin 4B,ARHGAP10,RGMB,hsa-miR-93-5p,and ZNF710-AS1-202 were not consistent or statistically significant after overexpression or knockdown of ZNF710-AS1-201,as determined by qRT-PCR.CONCLUSION Immune-related lncRNA ZNF710-AS1-201 facilitates the metastasis and invasion of GC cells.It appears that ZNF710-AS1-201 and ZNF710 have potential as effective targets for therapeutic intervention in GC.Nevertheless,it is still necessary to determine the specific targets of the ZNF710 TF.

THE MIB-1 PROLIFERATION INDEX AND MICROVESSEL COUNT IN EARLY GASTRIC CANCER:ASSOCIATION WITH LYMPH NODE METASTASIS

Objective Tumors with accelerated growth or high malignancy are thought to undergo active angio- genesis. Whereas by far, there is few study concerning the combination of MIB-1 proliferation index (MIB-1 PI) and tumor angiogenesis in carcinomas to show their significance in relate to clinicopathological parameters. In the present study, we evaluated the significance or MIB-1 PI and angiogenesis in early stage of gastric cancer. Our focus was es- pecially on the combination of MIB-1 PI and angiogenesis in relate to lymph node metastasis. Method Specimens from 95 patients with early gastric cancer were studied by means or immunohistochemistry using monoclonal MIB-1 and factor Ⅷ related antigen antibodies. Results The mean MIB-1 PI and microvessel count were 22.9% and 34.7, respectively. The MIB-1 PI did not correlate with microvessel count. Both correlated with depth of tumor invasion, lymphatic vessel invasion and lymph node metastasis. Multivarlate analysis showed that combined high MIB-1 PI/hy- pervascularity, as well as lymphatic vessel invasion and tumor size were independent factors that impact on lymph node metastasis. Conclusion A combination of the high MIB-1 PI/hypervascularity is a factor that related to lymph node metastasis in early gastric cancer.

Relationship between LYVE-1, VEGFR-3 and CD44 gene expressions and lymphatic metastasis in gastric cancer

AIM: To investigate the expression levels of lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), vascular endothelial growth factor receptor-3 (VEGFR-3) and CD44 genes and the relationship between their lev- els and clinicopathological parameters in gastric cancer.METHODS: Tissue samples were obtained from 33 patients (8 females) with gastric cancer. mRNA levels of LYVE-1, VEGFR-3 and CD44 in normal and tumor tissues were quantitatively measured using real time polymerase chain reaction. The results were correlated with lymph node metastasis, histological type and differentiation of the tumor, T-stage, and presence of vascular, perineural and lymphatic invasions. The distribution of molecules in the tissue was evaluated using immunohistochemistry. RESULTS: LYVE-1, CD44 and VEGFR-3 gene expression levels were significantly higher in gastric cancer than in normal tissue. While there was no correlation between gene expressions and clinicopathologic fea- tures such as histologic type, differentiation and stage, gene expression levels were found to be increased in conjunction with positive lymph node/total lymph node ratio and the presence of perineural invasion. A significant correlation was also found between LYVE-1 and CD44 over-expressions and perineural invasion and lymph node positivity in gastric cancers. When the dis- tribution of LYVE-1 antibody-stained lymphatic vessels in tissue was evaluated, lymphatic vessels were located intra-tumorally in 13% and peri-tumorally in 27% of the patients. Moreover, lymph node metastases were also positive in all patients with LYVE-1-staining. CONCLUSION: LYVE-1, VEGFR-3 and CD44 all play an important role in lymphangiogenesis, invasion and metastasis. LYVE-1 is a perfectly reliable lymphatic vessel marker and useful for immunohistochemistry.

Effects of angiopoietin-1 on attachment and metastasis of human gastric cancer cell line BGC-823

AIM： To evaluate the effects of angiopoietin-1 （Ang-1） on adhesion of gastric cancer cell line BGC-823 and expression of integrin β1, CD44V6, urokinase-type plasminogen activator （uPA） and matrix metalloproteinase-2 （MMP-2）. METHODS： BGC-823 cells were transfected transiently with adenovirus-Ang-1 （Ad-Ang-1）. Cells transfected transiently with adenovirus-green fluorescent protein （Ad-GFP） and untransfected cells were used as a negative and blank control group, respectively. The cell adhesion rate between cell and extracellular matrix （ECM） was determined by cell adhesion assay. To investigate whether Ang-1 could reinforce gastric carcinoma metastasis, we performed migration and invasion assays in BGC-823 cells. The mRNA and protein expression of integrin β1, CD44V6, uPA and MMP-2 were detected by reverse transcription polymerase chain reaction and Western blotting, respectively. The expression of integrin β1 and CD44V6 was measured by immunohistochemistry. RESULTS： BGC-823 cells were transfected successfully. The adhesion rate increased significantly in the Ad-Ang-1 group （P 〈 0.05）. The Ad-Ang-1-transfected group had a significant increase in migration and invasion compared with that of the mock-transfected and Ad-GFP groups. The mRNA and protein expression of integrin β1, CD44V6, uPA and MMP-2 in the Ad- Ang-1 group was higher than that in the Ad-GFP and blank control groups （P 〈 0.05）. Compared with mocktransfected and Ad-GFP groups, integrin 131 and CD44V6 expression intensity greatly increased （P 〈 0.05）. CONCLUSION： Transfection of Ang-1 into human gastric cancer cell line BGC-823 can significantly increase expression of integrin β1 and CD44V6, by which cell adhesion and metastasis to the ECM are promoted.

Down-regulation of miR-622 in gastric cancer promotes cellular invasion and tumor metastasis by targeting ING1 gene

AIM:To evaluate the biological and clinical characteristics of miR-622 in gastric cancer. METHODS:We analyzed the expression of miR-622 in 57 pair matched gastric neoplastic and adjacent non-neoplastic tissues by quantitative real-time polymerase chain reaction. Functional analysis of miR-622 expression was assessed in vitro in gastric cancer cell lines with miR-622 precursor and inhibitor. The roles of miR-622 in tumorigenesis and tumor metastasis were analyzed using a stable miR-622 expression plasmid in nude mice. A luciferase reporter assay was used to assess the effect of miR-622 on inhibitor of growth family,member 1 (ING1) expression. RESULTS:Expression of miR-622 was down-regulated in gastric cancer. MiR-622 was found involved in differentia-tion and lymphatic metastasis in human gastric cancer. Ectopic expression of miR-622 promoted invasion,tumorigenesis and metastasis of gastric cancer cells both in vitro and in vivo. ING1 is a direct target of miR-622. CONCLUSION:These findings help clarify the molecular mechanisms involved in gastric cancer metastasis and indicate that miR-622 modulation may be a bona fide treatment of gastric cancer.

Metastasis-associated in colon cancer-1 in gastric cancer: Beyond metastasis

Metastasis-associated in colon cancer-1(MACC1) is an oncogene that was first identified in colon cancer. The upstream and downstream of MACC1 form a delicate regulatory network that supports its tumorigenic role in cancers. Multiple functions of MACC1 have been discovered in many cancers. In gastric cancer(GC), MACC1 has been shown to be involved in oncogenesis and t umor progression. MACC1 overexpression adversely affects the clinical outcomes of GC patients. Regarding the mechanism of action of MACC1 in GC, studies have shown that it promotes the epithelialto-mesenchymal transition and accelerates cancer metastasis. MACC1 is involved in many hallmarks of GC in addition to metastasis. MACC1 promotes vasculogenic mimicry(VM) via TWIST1/2, and VM increases the tumor blood supply, which is necessary for tumor progression. MACC1 also facilitates GC lymphangiogenesis by upregulating extracellular secretion of VEGF-C/D, indicating that MACC1 may be an important player in GC lymphatic dissemination. Additionally, MACC1 supports GC growth under metabolic stress by enhancing the Warburg effect. In conclusion, MACC1 participates in multiple biological processes inside and outside of GC cells, making it an important mediator of the tumor microenvironment.

CXCR7/CXCL12 axis is involved in lymph node and liver metastasis of gastric carcinoma

AIM To investigate the role of CXC chemokine receptor (CXCR)-7 and CXCL12 in lymph node and liver metastasis of gastric carcinoma. METHODS In 160 cases of gastric cancer, the expression of CXCR7 and CXCL12 in tumor and matched tumoradjacent non-cancer tissues, in the lymph nodes around the stomach and in the liver was detected using immunohistochemistry to analyze the relationship between CXCR7/CXCL12 expression and clinicopathological features and to determine whether CXCR7 and CXCL12 constitute a biological axis to promote lymph node and liver metastasis of gastric cancer. Furthermore, the CXCR7 gene was silenced and overexpressed in human gastric cancer SGC-7901 cells, and cell proliferation, migration and invasiveness were measured by the MTT, wound healing and Transwell assays, respectively. RESULTS CXCR7 expression was up-regulated in gastric cancer tissues (P = 0.011). CXCR7/CXCL12 expression was significantly related to high tumor stage and lymph node (r = 0.338, P = 0.000) and liver metastasis (r = 0.629, P = 0.000). The expression of CXCL12 in lymph node and liver metastasis was higher than that in primary gastric cancer tissues (chi(2) = 6.669, P = 0.010; chi(2) = 25379, P = 0.000), and the expression of CXCL12 in lymph node and liver metastasis of gastric cancer was consistent with the positive expression of CXCR7 in primary gastric cancer (r = 0.338, P = 0.000; r = 0.629, P = 0.000). Overexpression of the CXCR7 gene promoted cell proliferation, migration and invasion. Silencing of the CXCR7 gene suppressed SGC-7901 cell proliferation, migration and invasion. Human gastric cancer cell lines expressed CXCR7 and showed vigorous proliferation and migratory responses to CXCL12. CONCLUSION The CXCR7/CXCL12 axis is involved in lymph node and liver metastasis of gastric cancer. CXCR7 is considered a potential therapeutic target for the treatment of gastric cancer.

Targeting BMI-1-mediated epitheliale-mesenchymal transition to inhibit colorectal cancer liver metastasis

Liver is the most common metastatic site for colorectal cancer(CRC),there is no satisfied approach to treat CRC liver metastasis(CRCLM).Here,we investigated the role of a polycomb protein BMI-1 in CRCLM.Immunohistochemical analysis showed that BMI-1 expression in liver metastases was upregulated and associated with T4 stage,invasion depth and right-sided primary tumor.Knockdown BMI-1 in high metastatic HCT116 and LOVO cells repressed the migratory/invasive phenotype and reversed epithelialemesenchymal transition(EMT),while BMI-1 overexpression in low metastatic Ls174 T and DLD1 cells enhanced invasiveness and EMT.The effects of BMI-1 in CRC cells were related to upregulating snail via AKT/GSK-3βpathway.Furthermore,knockdown BMI-1 in HCT116 and LOVO cells reduced CRCLM using experimental liver metastasis mice model.Meanwhile,BMI-1 overexpression in Ls174 T and DLD1 significantly increased CRCLM.Moreover,sodium butyrate,a histone deacetylase and BMI-1 inhibitor,reduced HCT116 and LOVO liver metastasis in immunodeficient mice.Our results suggest that BMI-1 is a major regulator of CRCLM and provide a potent molecular target for CRCLM treatment.

BMI-1 activates hepatic stellate cells to promote the epithelialmesenchymal transition of colorectal cancer cells

BACKGROUND Activated hepatic stellate cells(aHSCs)are the major source of cancer-associated fibroblasts in the liver.Although the crosstalk between aHSCs and colorectal cancer(CRC)cells supports liver metastasis(LM),the mechanisms are largely unknown.AIM To explore the role of BMI-1,a polycomb group protein family member,which is highly expressed in LM,and the interaction between aHSCs and CRC cells in promoting CRC liver metastasis(CRLM).METHODS Immunohistochemistry was carried out to examine BMI-1 expression in LM and matched liver specimens of CRC.The expression levels of BMI-1 in mouse liver during CRLM(0,7,14,21,and 28 d)were detected by Western blotting(WB)and the quantitative polymerase chain reaction(qPCR)assay.We overexpressed BMI-1 in HSCs(LX2)by lentivirus infection and tested the molecular markers of aHSCs by WB,qPCR,and the immunofluorescence assay.CRC cells(HCT116 and DLD1)were cultured in HSC-conditioned medium(LX2 NC CM or LX2 BMI-1 CM).CM-induced CRC cell proliferation,migration,epithelial-mesenchymal transition(EMT)phenotype,and transforming growth factor beta(TGF-β)/SMAD pathway changes were investigated in vitro.A mouse subcutaneous xenotransplantation tumor model was established by co-implantation of HSCs(LX2 NC or LX2 BMI-1)and CRC cells to investigate the effects of HSCs on tumor growth and the EMT phenotype in vivo.RESULTS Positive of BMI-1 expression in the liver of CRLM patients was 77.8%.The expression level of BMI-1 continued to increase during CRLM in mouse liver cells.LX2 overexpressed BMI-1 was activated,accompanied by increased expression level of alpha smooth muscle actin,fibronectin,TGF-β1,matrix metalloproteinases,and interleukin 6.CRC cells cultured in BMI-1 CM exhibited enhanced proliferation and migration ability,EMT phenotype and activation of the TGF-β/SMAD pathway.In addition,the TGF-βR inhibitor SB-505124 diminished the effect of BMI-1 CM on SMAD2/3 phosphorylation in CRC cells.Furthermore,BMI-1 overexpressed LX2 HSCs promoted tumor growth and the EMT phenotype in vivo.CONCLUSION High expression of BMI-1 in liver cells is associated with CRLM progression.BMI-1 activates HSCs to secrete factors to form a prometastatic environment in the liver,and aHSCs promote proliferation,migration,and the EMT in CRC cells partially through the TGF-β/SMAD pathway.

Up-regulation of T-lymphoma and metastasis gene 1 in gastric cancer and its involvement in cell invasion and migration

Background T-lymphoma and metastasis gene 1 （Tiaml） produces a guanine nucleotide exchange factor （GNEF） that regulates guanosine triphosphatase, which transforms guanosine diphosphate to guanosine triphosphate. Recently published data indicate that Tiaml was associated with gastric cancer. The aim of this study was to investigate biological effects and potential mechanisms of Tiara1 in gastric carcinoma. Methods We analyzed the expression of Tiaml in 114 pair-matched gastric neoplastic and adjacent non-neoplastic tissues by quantitative real-time PCR. We investigated Tiaml expression and its prognostic value for gastric cancer. Furthermore, the functions of Tiaml over-expression were analyzed with stable-expression Tiara1 plasmid in human gastric cancer cell lines. Results Tiaml expression was significantly associated with cell differentiation and lymphatic metastasis; expression of Tiaml mRNA was up-regulated in gastric cancer compared to pair-matched adjacent non-tumor tissues. Analyses of surgical tissue samples and 5-year survival of gastric cancer patients showed that those with strong Tiaml expression had significantly shorter overall survival time than those with negative Tiaml expression. Ectopic expression of Tiaml promoted cell growth, migration and invasion of gastric cancer cells in vitro. Conclusions In gastric cancer cells, Tiaml affects multiple properties associated with acquisition of the metastatic phenotype, and may be a marker of gastric cancer progression and metastasis in a subset of cancer.

Depression accelerates gastric cancer invasion and metastasis by inducing a neuroendocrine phenotype via the catecholamine/β_(2)-AR/MACC1 axis

Background:Depression is a common,easily ignored,accompanied disease of gastric cancer(GC)patients and is often observed with elevated plasma catecholamine levels.Depression frequently promotes GC progression and leads to poor clinical outcomes;however,the molecular mechanisms underlying depression-induced GC progression remain poorly understood.We aimed to study the effects of depression on GC progression and explore possible mechanisms mediating the action of depression-associated catecholamines on GC.Methods:Depression states of GC patients were graded using the Patient Health Questionnaire-9,and plasma catecholamine levels were examined by high performance liquid chromatography coupled with tandem mass spectrometry.Migrative and invasive GC cells were examined using transwell assays,and metastatic GC niches were imaged using bioluminescence technology in a depression mouse model established with chronic unpredictable mild stress.Mouse depression-like behaviors were assessed through sucrose preference,forced swimming,and tail suspension tests.Characteristics of the neuroendocrine phenotype were observed via RT-PCR,Western blotting,flow cytometry,and transmission electron microscopy.Results:Fifty-one GC patients(age:53.61±1.79 years;cancer duration:3.71±0.33 months;depression duration:2.37±0.38 months;male-to-female ratio:1.55:1)were enrolled in the study.Depression grade was significantly higher in GC patients showing higher plasma levels of catecholamines(epinephrine:P=0.018;noradrenaline:P=0.009),higher oncogene metastasis-associated in colon cancer-1(MACC1)level(P=0.018),and metastasis(P<0.001).Further,depression-associated catecholamine specifically bound to the beta-2 adrenergic receptor(β_(2)-AR)and upregulated MACC1 expression,and thus promoting neuroendocrine phenotypic transformation through direct binding betweenMACC1 and synaptophysin.Eventually,the neuroendocrine phenotypic transformation accelerated GC invasion in vitro and metastasis in vivo.However,β_(2)-AR antagonist ICI-118,551 or MACC1 silencing effectively blocked the catecholamineinduced neuroendocrine phenotypic transformation and eliminated depressionenhanced GC migration and invasion.Moreover,β_(2)-AR blocking or MACC1 silencing prevented GC metastasis attributed to a neuroendocrine phenotype in a depression mouse model.Conclusions:Catecholamine-induced neuroendocrine phenotypes of GC cells led to depression-accelerated GC invasion and metastasis via the β_(2)-AR/MACC1 axis,while β_(2)-AR antagonist or MACC1 silencing could reverse it,showing promising potential therapeutic strategies for improving the outcome of GC patients with comorbid depression.

Eight-year survival after advanced gastric cancer treated with S-1 followed by surgery

We report a case of advanced gastric cancer, with cervical, axillary, and abdominal paraaortic lymph node metastases, that was successfully treated with chemotherapy and surgery. The disease was initially considered unresectable, and the patient was treated with orally administered S-1. Chemotherapy was effective, and all lymph node metastases disappeared after 6 courses. After 27 mo of chemotherapy, the patient underwent curative surgery, with subtotal gastrectomy and lymph node dissection. Histopathological examination revealed many viable poorly differentiated adenocarcinoma cells in the stomach, but no cancer cells in the lymph nodes. The patient is alive, without recurrence, 8 years later. This, therefore, is a case report of an 8-year survivor of advanced gastric cancer with distant lymph node metastasis.

MACC1 upregulation promotes gastric cancer tumor cell metastasis and predicts a poor prognosis

In various studies, metastasis associated with colon cancer 1 （MACC1） has been frequently reported to be abnormally highly expressed in human lung cancer, colon cancer, and hepatocellular carcinoma. Our study focuses on the association of MACC1 expression with gastric cancer （GC）. During our experiment, the MACC1 expression was tested in 105 GC samples using an immunohistochemical （IHC） method. The clinical characteristics and prognosis of these patients were summarized. During analysis, MACC1 distribution in GC samples with distant metastasis was higher than that in normal samples and in tumors with no dissemination. Subsequently, a lower 5-year survival rate had a strong correlation with high MACC1 expression. As a consequence, the present results suggest that MACC1 is more frequently expressed in a poor prognosis phenotype of GC and acts as a promising prognostic prediction parameter for GC.

m^(6)A-mediated regulation of PBX1-GCH1 axis promotes gastric cancer proliferation and metastasis by elevating tetrahydrobiopterin levels

Background:Methyltransferase 3(METTL3)-mediated N6-methyladenosine(m^(6)A)RNA modification has been demonstrated to be a potential factor in promoting gastric cancer(GC).METTL3 regulates a series of signaling pathways by modifying various mRNAs.This study aimed to identify novel METTL3-mediated signaling pathways and explored possible targets for use in the clinical setting of gastric cancer.Methods:To investigate the proliferation and metastatic capacity ofGCcell lines with METTL3 knockdown,a xenograft,lung metastasis,and popliteal lymph node metastasis model was used.Them^(6)A-modified RNA immunoprecipitation(Me-RIP)sequence was utilized to explore the target mRNAs of METTL3.Cell counting kit 8 and transwell assays were performed to investigate the promoting function of pre-B cell leukemia homeobox 1(PBX1)and GTP cyclohydrolase 1(GCH1).Western blotting and chromatin immunoprecipitation were employed to confirm the involvement of the METTL3-PBX1-GCH1 axis.ELISA and liquid chromatography-mass spectrometry were used to explore the biological function of tetrahydrobiopterin(BH_(4)).Results:Knockdown of METTL3 suppressed xenograft tumor growth and lung/lymph node metastasis in vivo.Mechanistically,we found that METTL3 combined with and stabilized PBX1 mRNAs.Chromatin immunoprecipitation(ChIP)and further experiments suggested that PBX1 acted as a transcription factor inducing GCH1 expression.Moreover,the METTL3-PBX1-GCH1 axis increased BH_(4)levels in GC cells,thereby promoting tumor progression.Conclusions:This study suggested that METTL3 enzymes promote tumor growth and lung/lymph node metastasis via METTL3-PBX1-GCH1 axis increasing BH_(4)levels in GC.

Feedback regulation between phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1 and transforming growth factor β1 and prognostic value in gastric cancer

BACKGROUND Phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1(PREX1)was reported to be overexpressed in some cancers and involved in cancer development,but its expression and significance in gastric cancer remain unclear.AIM To evaluate the expression of PREX1 in gastric cancer and its significance in the development of gastric cancer,especially to evaluate the potential mechanism of PREX1 in gastric cancer.METHODS Bioinformatic analysis was performed in order to examine the expression of PREX1 in gastric cancer.The relationship between the survival rate of gastric cancer patients and PREX1 expression was assessed by Kaplan Meier portal.The Gene Set Enrichment Analysis and the correlation between PREX1 and transforming growth factor(TGF)β1 pathway-related mediators were evaluated by cBioPortal for Cancer Genomics.Western blotting and reverse transcriptase polymerase chain reaction assay were used to test the role of TGFβ1 on the expression of PREX1.Western blotting and dual-luciferase reporter system was used to evaluate the effect of PREX1 on the activation of TGFβ1 pathway.Wound healing and Transwell assay were used to assess the effect of PREX1 on the metastasis activity of gastric cancer cells.RESULTS PREX1 was overexpressed in the gastric tumors,and the expression levels were positively associated with the development of gastric cancer.Also,the high expression of PREX1 revealed poor prognosis,especially for those advanced and specific intestinal gastric cancer patients.PREX1 was closely involved in the positive regulation of cell adhesion and positively correlated with TGFβ1-related mediators.Furthermore,TGFβ1 could induce the expression of PREX1 at both the protein and mRNA level.Also,PREX1 could activate the TGFβ1 pathway.The induced PREX1 could increase the migration and invasion activity of gastric cancer cells.CONCLUSION PREX1 is overexpressed in gastric cancer,and the high level of PREX1 predicts poor prognosis.PREX1 is closely associated with TGFβsignaling and promotes the metastasis of gastric cancer cells.

Micro RNA-331 inhibits development of gastric cancer through targeting musashi1

BACKGROUND The molecular mechanisms involved in micro RNAs(mi RNAs)have been extensively investigated in gastric cancer(GC).However,how mi R-331 regulates GC pathogenesis remains unknown.AIM To illuminate the effect of mi R-331 on cell metastasis and tumor growth in GC.METHODS The q RT-PCR,CCK8,Transwell,cell adhesion,Western blot,luciferase reporter and xenograft tumor formation assays were applied to explore the regulatory mechanism of mi R-331 in GC.RESULTS Downregulation of mi R-331 associated with poor prognosis was detected in GC.Functionally,mi R-331 suppressed cell proliferation,metastasis and tumor growth in GC.Further,mi R-331 was verified to directly target musashi1(MSI1).In addition,mi R-331 inversely regulated MSI1 expression in GC tissues.Furthermore,upregulation of MSI1 weakened the inhibitory effect of mi R-331 in GC.CONCLUSION mi R-331 inhibited development of GC through targeting MSI1,which may be used as an indicator for the prediction and prognosis of GC.

Impact of duration of adjuvant chemotherapy in radically resected patients with T4bN1-3M0/TxN3bM0 gastric cancer

AIM To provide evidence regarding the postoperative treatment of patients with T4 b N1-3 M0/Tx N3 b M0 gastric cancer, for which guidelines have not been established. METHODS Patients who had undergone curative resection between 1996 and 2014 with a pathological stage of T4 b N1-3 M0/Tx N3 b M0 for gastric cancer were retrospectively analyzed; staging was based on the 7 th edition of the American Joint Committee on Cancer staging system. The clinicopathological characteristics, administration of adjuvant chemotherapy, and patterns of recurrence were studied. Univariate and multivariate analyses of prognostic factors were conducted. The chemotherapeutic agents mainly included fluorouropyrimidine, platinum and taxanes, used as monotherapy, doublet, or triplet regimens. Patterns of first recurrence were categorized as locoregional recurrence, peritoneal dissemination, or distant metastasis.RESULTS The 5-year overall survival(OS) of the whole group(n = 176) was 16.8%, and the median OS was 25.7 mo(95%CI: 20.9-30.5). Lymphovascular invasion and a node positive rate(NPR) ≥ 0.8 were associated with a poor prognosis(P = 0.01 and P = 0.048, respectively). One hundred forty-seven(83.5%) of the 176 patients eventually experienced recurrence; the most common pattern of the first recurrence was distant metastasis. The prognosis was best for patients with locoregional recurrence and worst for those with peritoneal dissemination. Twelve(6.8%) of the 176 patients did not receive adjuvant chemotherapy, while 164(93.2%) patients received adjuvant chemotherapy. Combined chemotherapy, including doublet and triplet regimens, was associated with a better prognosis than monotherapy, with no significant difference in 5-year OS(17.5% vs 0%, P = 0.613). The triplet regimen showed no significant survival benefit compared with the doublet regimen for 5-year OS(18.5% vs 17.4%, P = 0.661). Thirty-nine(22.1%) patients received adjuvant chemotherapy for longer than six months; the median OS in patients who received adjuvant chemotherapy for longer than six months was 40.2 mo(95%CI: 30.6-48.2), significantly longer than the 21.6 mo(95%CI: 19.1-24.0) in patients who received adjuvant chemotherapy for less than six months(P = 0.001).CONCLUSION Patients with T4 b N1-3 M0/Tx N3 b M0 gastric cancer showed a poor prognosis and a high risk of distant metastasis. Adjuvant chemotherapy for longer than six months improved outcomes for them.

Overexpression of MiR-633 Suppresses the Tumorigenicity of Gastric Cancer Cells and Induces Apoptosis by Targeting MAPK1

Objective MicroRNA(miRNA/miR)-633 is dysregulated in several types of cancers and is involved in tumorigenesis.However,the function and role of this miRNA in gastric cancer(GC)are not fully understood.The aim of the present study was to evaluate miR-633 expression in GC cell lines and in GC tissue vs.adjacent normal tissue,and to determine its association with clinicopathological data.This work was extended to investigate the effects of miR-633 overexpression on tumor cells in vitro.Methods Reverse transcription-quantitative PCR(RT-qPCR)was used to detect and compare the expression level of miR-633 in GC cells,as well as in GC and normal adjacent tissue samples.The clinical significance of miR-633 was also analyzed.MiR-633 lentivirus(LV-miR-633)and negative control lentivirus(LV-NC)were generated and used to transduce SGC-7901 and HGC-27 GC cells in order to analyze the effect of miR-633 on their phenotype.The effects of miR-633 overexpression on GC cell proliferation,apoptosis,migration and invasion were investigated.The target gene of miR-633 was predicted,then confirmed using a dual luciferase reporter gene assay,RT-qPCR and Western blotting.Results MiR-633 was significantly downregulated in GC cell lines,as well as in GC tissue compared with adjacent normal tissue.Moreover,miR-633 expression was associated with the tumor/node/metastasis(TNM)stage,invasion depth,Borrmann classification and lymph node metastasis(P<0.05).Compared with the LV-NC group,transduction with LV-miR-633 reduced the proliferation,the number of clones,the wound healing rate,the number of invading cells and the number of cells in the G1 phase of the cell cycle(P<0.01).LV-miR-633 also increased the apoptosis rate(P<0.01).The expression level of mitogen-activated protein kinase(MAPK)1,high-mobility group box 3(HMGB3),claudin 1(CLDN1)and MAPK13 were downregulated in LV-miR-633-transduced cells(P<0.01).The dual luciferase reporter assay confirmed that the 3′-untranslated region of MAPK1 was the target site of miR-633(P<0.01).Conclusion MiR-633 acts as a tumor suppressor in GC,and its expression level is associated with TNM stage,invasion depth,Borrmann type and lymph node metastasis.Overexpression of miR-633 inhibits the proliferation and migration of GC cells and induces apoptosis and cell cycle arrest at the in G1 phase.In addition,miR-633 negatively regulates the expression of MAPK1,HMGB3,CLDN1 and MAPK13 and directly targets MAPK1.

Bmi-1基因过度表达与胃癌分化、转移及预后的关系

目的探讨胃癌组织中Bmi-1基因mRNA表达与胃癌分化、转移及临床预后的关系。方法收集我院2006年5月～2006年11月共42例行胃癌手术切除标本,提取肿瘤及癌旁组织配对标本的总RNA,用RT-PCR方法测定Bmi-1基因表达,并结合临床资料,对Bmi-1基因差异表达与胃癌病人临床表现的相关性进行分析研究。结果42例配对标本分别进行Bmi-1mRNA荧光检测比较,29例标本的肿瘤组织中Bmi-1基因mRNA表达明显高于癌旁正常胃组织。Bmi-1mRNA的表达与胃癌大小、淋巴结转移和浸润深度密切相关(P<0.05),而与患者的性别、年龄、肿瘤分化程度等无关(P>0.05)。并且Bmi-1mRNA阳性表达者生存率明显低于阴性者。结论Bmi-1基因在胃癌组织中表达状态与胃癌的生长和浸润转移关系密切,Bmi-1基因mRNA可望作为胃癌病情发展及指导临床治疗的标记物之一,Bmi-1mRNA的测定有助于判断肿瘤预后。