Investigation Of Biological Characteristics Of KLHL6 Gene In Gastric Cancer

BackgroundThis study was to investigate KLHL6 expression in gastric cancer and matched adjacent nontumour tissues to explore the clinicopathological features of patients with gastric cancer and KLHL6 expression in gastric cancer tissues.The detection of KLHL6 protein and mRNA expression levels in GC cell lines HGC-27,MGC-803,SGC-7901,BGC-823,SUN-1,KATO-III and AGS and in normal gastric cell line GES-1 was also studied.In addition,KLHL6 expression in gastric cancer cells was downregulated.Using proliferation,migration and invasion assays,tumour growth in an in vivo experimental model was analysed to investigate the effect of KLHL6 on the biological behaviour of gastric cancer cells.MethodsThe surgical paraffin sections of 84 gastric adenocarcinoma,including cancer tissues and corresponding adjacent nontumour tissue,and the corresponding complete clinical follow-up information were collected from the Department of Gastroenterology of the Tianjin Medical University Cancer Hospital between November 2003 and September 2007.The investigation included a total of 15 cases of atrophic gastritis and 15 cases of gastric dysplasia in Tianjin Xiqing Hospital,where the included patients with benign gastric diseases were admitted from March 2000 to June 2010.Immunohistochemistry(IHC)was used to detect KLHL6 protein expression in 84 cases of gastric cancer and its corresponding adjacent nontumour tissue.The relationship among KLHL6 protein expression,clinicopathological characteristics and prognosis of patients with gastric cancer was evaluated.IHC method was used to detect KLHL6 protein expression in 15 cases of atrophic gastritis and 15 cases of gastric atypical hyperplasia.KLHL6 mRNA expression in different human gastric cancer cell lines and human normal gastric mucosa cells was detected by semiquantitative reverse transcription and polymerase chain reaction.Western blot was used to detect KLHL6 protein expression in different human gastric cancer and human normal gastric mucosa cell lines.Downregulated KLHL6 expression in human gastric cancer cell line MGC-803 was observed by colony formation,dimethylthiazolyl-2-5-diphenyltetrazolium bromide,cell-based scratch and Transwell tumour cell invasion assays.The effect of KLHL6 gene on the biological behaviour of gastric cancer cells was evaluated.Results1.The positive expression rate of KLHL6 in gastric cancer tissues was significantly higher than in adjacent nontumour tissues(42.86% vs 4.76%,P<0.001).2.The protein expression rate of KLHL6 in 15 cases of atrophic gastritis was 6.67%,whereas the protein rate of KLHL6 in 15 cases of gastric dysplasia was 13.33%.3.The mRNA and protein expression levels of KLHL6 in gastric cancer cell lines was significantly higher than in GES-1 cell line(P<0.05).4.Univariate survival analysis showed that age,tumour size,N stage and KLHL6 expression were associated with the prognosis of patients with gastric cancer(P<0.05).Multivariate analysis revealed that tumour size,N stage and KLHL6 expression were independent outcome predictors(P<0.05).5.Downregulated KLHL6 expression in MGC-803 gastric cancer cells reduced colony formation,viability,proliferation,migration and invasion.Conclusions1.KLHL6 expression related to the occurrence and development of gastric cancer suggested that KLHL6 plays a role in gastric cancer development.2.KLHL6 protein expression is an independent prognostic factor in patients with gastric cancer after radical operation.Patients with high KLHL6 protein expression have poor prognosis.KLHL6 protein expression was used as a prognostic indicator in patients with gastric cancer.3.KLHL6 plays a significant promoting role in gastric cancer occurrence and progression,and its mechanism involves many aspects,such as proliferation,migration and invasion.