| Objective:Gastric cancer is one of the common malignant tumors in China,and its high morbidity and high mortality seriously threaten human health.According to the latest cancer statistics in 2018,gastric cancer(GC)has the second-highest morbidity and mortality rate in China.Research data shows that liver metastasis is one of the main causes of gastric cancer treatment failure.After liver metastasis occurs,the survival period of the patients is very short,and the survival of untreated cases is only 3months to 5 months,which brings greater difficulties to clinical diagnosis and treatment.Therefore,early detection of liver metastases from cancer cells at the molecular level and discussion of their molecular mechanisms may provide new molecular markers or targets for early warning and intervention of gastric cancer liver metastases,thereby improving the comprehensive diagnosis and treatment of gastric cancer.Research suggests that autophagy,as an important influencing factor in tumorigenesis and development,can enhance the tumor’s ability to resist nest loss and apoptosis,and autophagy is regulated by related molecules.The study found that anti-nesting apoptosis is the primary factor for the ability of tumor cells to acquire invasion and metastasis.The research team used Human LncRNA Microarray to establish the expression profile of LncRNAs related to liver metastasis of gastric cancer in the early stage and found that LncRNA LINC01207 in gastric cancer patients showed a high expression state,but the research on related mechanisms has not made breakthrough progress.Methods:1.Three cases of gastric cancer with simultaneous and heterochronous liver metastasis were selected,and the expression of LncRNAs in cancer and its matched adjacent tissues was detected by high-throughput LncRNA chip.The high expression LncRNA LINC01207 was selected for the study.2.Candidate molecule LINC01207 clinical significance study: 150 pairs ofgastric cancer and adjacent normal tissues were detected,using fluorescence real-time quantitative PCR method to detect LINC01207,autophagy-related molecules LC3 B,ATG7 gene mRNA levels,analysis of LINC01207 and gender,age,tumor site,tumor diameter,Lauren classification,tissue differentiation degree,depth of invasion,lymph node metastasis,number of liver metastases,time of liver metastasis,TNM stage,Helicobacter pylori(HP)infection,CEA level,and autophagy-related molecule LC3 B,ATG7 gene correlation.3.Research on LINC01207 cell level:(1)Detect normal gastric cell line GFS-1and common gastric cancer cell lines,use quantitative PCR to determine the expression of LINC01207,and select AGS and BGC7901 for follow-up research.(2)We constructed LINC01207 small interfering RNA and overexpression vector,treated AGS and BGC7901 cell lines with liposome transfection,observed the effect of down-regulation and up-regulation on proliferation,clone,migration,and invasion,and observed the effect on liver metastasis with a nude mouse model.4.LINC0120 molecular mechanism research: From the perspective of autophagy and anoikis resistance,the molecular mechanism of LINC01207 overexpression to promote liver metastasis of gastric cancer was discussed.Results:1.LncRNA chip detection found that compared with normal tissues,LINC01207 was highly expressed in gastric cancer,which was 36.1108±0.0005(P = 0.0128).2.The detection results of 150 cases of gastric cancer and their matched normal tissues were divided into two groups according to the expression of LINC01207.It was found that LINC01207 and the depth of tumor invasion(P= 0.009),lymph node metastasis(P=0.001),TNM stage(P=0.000),number of liver metastases(P= 0.022),and the time of liver metastasis after gastric cancer surgery(P=0.001)0.003)Obviously related.It was also found that high expression of LINC01207 was closely related to the expression level of autophagy-related molecules ATG7(P = 0.000)and LC3(P= 0.002),but was related to gender(P= 0.403),age(P = 0.239),and tumor site(P=0.134),tumor diameter(P=0.102),Lauren classification(P=0.934),degree of differentiation(P=0.106),carcinoembryonic antigen(CEA)(P=0.361)were not significantly correlated.3.Gastric cancer cells are different from GES-1,although LINC01207 hasincreased,the degree is different in different cell lines.Subsequent application of AGS and SGC7901 as a cell research model.4.Molecular phenotype study showed that after gastric cancer AGS and SGC7901 cells were transfected with siRNA,compared with the blank control group and the empty control group,the proliferation of cancer cells in the siRNA group was significantly weakened,the number of gram drops was greatly reduced,and cell migration was inhibited.The ability to invade significantly decreased.The molecular overexpression group showed the opposite phenomenon.Compared with the blank control group and the empty control group,the cancer cell proliferation in the LINC01207 group was obvious,the number of clones increased significantly,the cell migration was enhanced,and the invasion ability was significantly improved.The same phenomenon exists in animal experiments.The liver metastases of naked mice in the LINC01207 siRNA group decreased,while the liver metastases in the overexpression group increased.It was also found that compared with the control group,the overexpression of LINC01207 had a promoting effect on the apoptosis resistance of gastric cancer estrus cells;the autophagosomes of the LINC01207 overexpression group increased significantly,and the autophagy-related molecules LC3 B and ATG7 increased significantly.5.The molecular mechanism study found that the number of cells lost to nesting in cells transfected with LINC01207 alone was significantly reduced,while the number of cells lost to nesting in cells co-transfected with LINC01207 and ATG7 siRNA increased.WB detection found that the LC3 B and survivin proteins in the LINC01207 overexpression group were significantly increased,while the LC3 B and survivin proteins in the cotransfection group were significantly decreased.Conclusion:1.The results in vivo and in vitro suggest that LINC01207 may be one of the important molecular markers for gastric cancer liver metastasis.2.LINC01207 may activate autophagy,which promotes resistance to anoikis apoptosis,thereby promoting liver metastasis of gastric cancer. |
PDF Full Text Request