| Research background:The DEAD-boxRNA helicases family is present in almost all known organisms and is involved in almost all processes ofRNA metabolism in organism dependent on energy generated by ATP hydrolysis,including important roles in transcription,translation,ribosome biogenesis,splicing of mRNA precursors,and nuclearRNA translocation.In recent years,an increasing number of studies have shown that the DEAD-box protein family(DDX)plays an important role in the development and progression of a variety of tumors,in addition to its currently known functions.DDX27 is a member of the DEAD-boxRNA helicases family,and its protein is localized in the nucleus.DDX27 is involved in ribosomalRNA(rRNA)processing in addition to its ATP-dependentRNA unwinding enzyme function,and also regulates the 3′ terminal formation of ribosomal 47 SRNA.The specific physiological mechanisms of DDX27 protein are still not fully understood.DDX27 has been found to be overexpressed in gastric cancer tissues and is associated with poor prognosis.Another study showed that in colorectal cancer,high expression of DDX27 promoted the proliferation,migration and invasion of colorectal cancer cells.However,there are still few studies on the role of DDX27 in malignant tumors,and there are no studies on its mechanism of action in renal clear cell carcinoma.Research objective:We investigated the correlation between DDX27 expression and the clinical prognosis of patients with clear cell renal cell carcinoma(ccRCC)and the independent risk factors affecting the survival prognosis of ccRCC patients,and investigated what biological functions DDX27 plays in renal clear cell carcinoma cells through in vitro cell experiments.Through our study,we hope to lay a preliminary foundation for exploring the role of DDX family in the development of renal carcinoma,to provide some research basis for seeking the pathogenesis of ccRCC and finding new therapeutic targets for ccRCC,and to explore a possible novel molecular marker to predict the outcome and prognosis of ccRCC patients.Research methods:1)First,the clinical and pathological data of patients with renal clear cell carcinoma from The Cancer Genome Atlas(TCGA)and the expression equivalents of DDX27 gene in the corresponding patients were downloaded using cBioPortal.The relationship between DDX27 and clinicopathological features in ccRCC-TCGA was analyzed by the median method into DDX27 high and low expression groups,and the effect of DDX27 on the prognosis of ccRCC patients was investigated.2)The expression of DDX27 in renal clear cell carcinoma cell lines was interfered by transient transfection of siRNA.QPCR and Western-blot were used to verify the transfection efficiency,and scratch,Transwell migration,and invasion assays were used to investigate the effect of DDX27 on the biological behavior of renal clear cell carcinoma cell lines in vitro.Research results:1)Analysis of ccRCC patient data and DDX27 mRNA expression downloaded from TCGA public database,Kaplan-Meier survival curve showed that patients in the low expression DDX27 mRNA group had better OS,DFS,and the difference was statistically significant(P < 0.05).Pearson chi-square test showed that the expression of DDX27 was not related to gender,race,and tumor side(P > 0.05),but to age,tumor pathological grade,pathological T stage,and tumor pathological TNM stage(P< 0.05).2)Univariate and multifactorial analysis of the prognostic relationship between DDX27 expression and overall survival of renal cancer patients,DDX27 could be used as an independent risk factor affecting the prognosis of renal clear cell carcinoma.3)DDX27 could be effectively knocked down in 786-O kidney cancer cell line by siRNA interference technology.in vitro cell function assay results showed that cell migration and invasion ability were inhibited after the kidney cancer cell line was knocked down by DDX27.Conclusion:1)The expression of DDX27 correlated with age,tumor pathological grade,pathological T-stage,and tumor pathological TNM stage,while the OS、DFS of patients with high DDX27 expression was shorter than that of the low expression group,and DDX27 was an independent risk factor affecting the prognosis of renal clear cell carcinoma,all of which suggested that DDX27 could be used as a marker for prognosis judgment of ccRCC.2)In vitro cellular assays transiently transfected with knockdown DDX27 resulted in a significant decrease in the migration and invasive ability of kidney cancer cells,suggesting that DDX27 plays a pro-oncogene role in the development of ccRCC.3)DDX27 is expected to be a potential prognostic molecular marker and therapeutic target for ccRCC. |
