Study On The Expression And Role Of MFN2 In Gastric Cancer

Objective: To detect the expression level of Mitofusin 2(MFN2)in gastric cancer and matched normal gastric tissues by immunohistochemistry,and analyze the correlation between the expression level of MFN2 in gastric cancer and clinicopathological characteristics.The expression level of MFN2 in human gastric cancer cell line SGC-7901 was changed by plasmid transfection to explore the effect of MFN2 expression level on the proliferation,invasion and migration of human gastric cancer cell line SGC-7901.Methods: 1.Select 32 patients with gastric cancer confirmed by pathology for the first time after surgery,collect the clinicopathological information of the patients,take the gastric cancer tissue and matched normal gastric tissue wax blocks of the above patients,make paraffin sections,and use immunohistochemistry to detect the expression level of MFN2 in gastric cancer tissue and matched normal gastric tissue,and score,and statistically analyze the correlation between the expression level of MFN2 in gastric cancer tissue and clinicopathological characteristics.2.Human gastric cancer cell line SGC-7901 was cultured,and the expression level of MFN2 in human gastric cancer cell line SGC-7901 was changed by plasmid transfection,and was divided into: MFN2 knockdown negative control group(NC);MFN2 knockdown group(si-MFN2);MFN2overexpression negative control group(Vector);MFN2 overexpression group(MFN2-OE).Western blot and RT-q PCR were used to detect the expression level of MFN2 protein and m RNA in human gastric cancer cell line SGC-7901 in each group to verify the transfection efficiency.The effect of MFN2 expression on the proliferation of human gastric cancer cell line SGC-7901 was detected by CCK-8 method;Transwell cell invasion and migration test and cell scratch test were used to detect the effect of MFN2 expression level on the invasion and migration ability of human gastric cancer cell line SGC-7901;Western blot was used to detect the expression level of epithelial-mesenchymal transition(EMT)related factors in human gastric cancer cell line SGC-7901.Results: 1.The results of immunohistochemistry showed that the score of MFN2 expression level in gastric cancer tissue was lower than that in matched normal gastric tissue(P<0.001).The expression level score of MFN2 in gastric cancer tissue of patients with normal CEA and CA19-9 before operation was higher than that of patients with elevated CEA and CA19-9 before operation(P<0.05);There was no significant correlation between the expression level of MFN2 in gastric cancer tissue and the patient’s sex,age,preoperative hemoglobin and albumin levels(P>0.05).The expression level score of MFN2 in gastric cancer tissue of patients with the maximum diameter of 5 cm and above was lower than that of patients with the maximum diameter of less than 5 cm(P<0.05);The expression level score in poorly differentiated patients with gastric cancer was lower than that in moderately well differentiated patients(P;The score of expression level in gastric cancer tissue of patients with positive vascular and nerve invasion was lower than that of patients with negative vascular and nerve invasion(P<0.05);The expression level score of gastric cancer in patients without lymph node metastasis was higher than that in patients with lymph node metastasis(P;In terms of the depth of tumor invasion,the expression level of MFN2 in gastric cancer tissue of T1+T2 patients was higher than that of T3+T4 patients(P<0.05);In the clinicopathological stage,the expression level of MFN2 in gastric cancer tissues of patients with stage I+II was higher than that of patients with stage III+IV(P<0.05).2.(1)Western blot and RT-q PCR were used to detect the expression level of MFN2 protein and m RNA in each group.The results showed that the expression level of MFN2 protein and m RNA in the MFN2 knockdown group was relatively lower than that in the MFN2 knockdown negative control group(P<0.05);Compared with the negative control group of MFN2 overexpression,the expression level of MFN2 protein and m RNA in the MFN2 overexpression group was relatively higher(P<0.05).(2)The results of CCK-8 method showed that there was no significant difference in the proliferation of human gastric cancer cells at 24 h,48h,72 h and 96 h after transfection of knockdown MFN2(P>0.05);The results of cell scratch test showed that the migration rate of MFN2 knockdown group at 24 h,48h and 72 h was significantly higher than that of MFN2 knockdown negative control group(P<0.05);The results of Transwell cell invasion and migration experiment showed that the number of invasion and migration cells in the MFN2 knockdown group at 48 hours was significantly higher than that in the MFN2 knockdown negative control group(P<0.05),and the number of invasion and migration cells in the MFN2 overexpression group at 48 hours was significantly lower than that in the MFN2 overexpression negative control group(P<0.05).(3)Western blot was used to detect the protein expression level of EMT-related factors E-cadherin and Vimentin in the cells of each group.The results showed that there was no significant change in the protein expression water of E-cadherin and Vimentin in the MFN2 knockdown group compared with the MFN2 knockdown negative control group and the MFN2 overexpression group compared with the MFN2 overexpression negative control group(P>0.05).Conclusion: 1.The expression level of MFN2 in human gastric cancer tissue was significantly lower than that of its paired normal gastric tissue;2.The expression level of MFN2 was negatively correlated with CEA,CA19-9,tumor size,depth of invasion,lymph node metastasis,clinicopathological stage,histological grade,and neurovasculature invasion.3.The decrease in the expression level of MFN2 had no significant effect on the proliferation capacity of the human gastric cancer cell line SGC-7901;4.Decreased MFN2 expression level can promote the invasion and migration ability of human gastric cancer cell line SGC-7901,and elevated MFN2 expression level can inhibit the invasion and migration ability of human gastric cancer cell line SGC-7901,but its regulatory pathway may not be subject to EMT process.