Preliminary Study Of Ring Finger Protein 180 Inhibiting The Progression Of Gastric Cancer Via The Signal Transducer And Activator Of Transcription 3

BackgroundRing finger protein 180(RNF180),a novel binding type E3 ubiquitin ligase,regulates the degradation of many intracellular proteins,such as the damaged proteins and some transcription factors,participates in the occurrence and development of various malignant tumors including gastric cancer.Signal transducers and activators of transcription 3(STAT3),a highly concerned oncogene,can promote lymph node metastasis and further affect the prognosis of gastric cancer by promoting lymphangiogenesis and other processes.This study aimed to investigate the expression levels correlations of RNF180 and STAT3 in gastric cancer tissues.And the regulation of RNF180 on STAT3 was investigated by molecular biology experiments.MethodsThe tumor tissues and matched adjacent non-tumor tissues of gastric cancer patient from January 2004 to September 2007 were collected and cent to Shanghai Outdo Biotech Company(Shanghai China)for microarrays(TMAs).The expression of RNF180 and STAT3 were observed in 112 gastric cancer tissues and 112 matched adjacent non-tumor tissues by immunohistochemical staining.The relationship between the expression levels of RNF180 and STAT3 were evaluated.The expression levels of RNF180 and STAT3 in the different GC cell lines and in the normal gastric mucosa cell line were detected by Semi-quantitative reverse transcription and polymerase chain react(Sq RT-PCR)and Western blot(WB).RNF180 expression vector was transfected to explore the effect of RNF180 on the maglinant biology characteristics.The differential proteins in the RNF180 overexpression group and the control group were detected by the Isobaric Tags for Relatives and Absolute(i TRAQ)experiments to find potential downstream molecules of RNF180.The transcriptome sequencing was used to detect the difference in m RNA expression between the RNF180 overexpression group and the control group,in order to obtain the regulatory genes and related signaling pathways related to RNF180.Results1.The positive expression rate of RNF180 in gastric cancer tissues was 5.4%(6/112),which was significantly lower than that in adjacent non-tumor tissues(8.9%,10/112).The difference was statistically significant(P=0.009).The positive expression rate of STAT3 in gastric cancer tissues was 89.3%(100/112),which was significantly higher than that in adjacent non-tumor tissues(25.0%,28/112).There was a correlation between RNF180 and STAT3 expression levels(r=-0.174,P=0.033).2.Compared with the control group,upregulated RNF180 expression in gastric cancer cells reduced colony formation,viability,proliferation and migration.3.Compared with the control group,the expression level of STAT3 was decreased in the RNF180 overexpression group.4.The results of i TRAQ showed that the expression level of STATs protein in RNF180 overexpression group was significantly down-regulated compared with the control group.5.Transcriptome sequencing: There was no significant change in the transcriptional level of STAT3 in the RNF180 overexpressing group compared to the control group.6.Animal experiments: Compared with the control group,the RNF180 overexpression group has a small tumor volume.Conclusions1.The expression level of RNF180 in gastric cancer tissues was low,and its expression level was negatively correlated with the expression level of STAT3.2.RNF180 can inhibit the proliferation and migration of gastric cancer cells and downregulated the expression of STAT3.3.RNF180 can inhibit tumor growth in nude mice.4.RNF180 may affect the lymph node metastasis of gastric cancer by regulating the expression of STAT3 or its upstream signaling molecules,thus affecting the prognosis of gastric cancer patients.