| Objective: Renal cell carcinoma(Renal cell carcinoma,RCC)is a common urological tumor,accounting for 2%-3% of adult malignancies.In recent years,the incidence of RCC increased year by year,it become a serious threat to human health.In developed countries,the incidence rate of RCC become higher,and most of the RCC is sporadic.The pathogenesis of RCC is complex,the epidemiological data shows that all forms of tobacco exposure is the recognized risk factors,and with the tobacco cumulative dose and duration of its dangerous degree increased,and obesity,high protein,high fat,low vegetable diet is also a risk factor.With the development of molecular biological study.In addition to these risk factors,the incidence of RCC is associated with gene mutation inactivation and epigenetics.Especially the DNA methylation changes,has become an important method in the research of tumor.RASSF family(RASSF1-RASSF10)is a negative regulator gene family of Ras signaling pathway,and most of its members are due to the methylation of gene promoter,which leads to the loss of expression,and in many kinds of tumor progression.A research have been reported in the magzaine that the hypermethylation of RASSF10 promoter in thyroid cancer,melanin tumor,prostate cancer,Acute Leukemia in Children.RASSF10 is a potential tumor suppressor gene,which has not been reported in RCC.And we don’t know its expression level and methylation status.This article aims to analyze the expression and methylation of RASSF10 gene and know their differences in human RCC tissues and corresponding normaltissues.To know the difference between methylation status and the expression of mRNA.According to statistical analysis on the data of methylation results,clinical data,expression level,we can explore the function of RASSF10 in the process of RCC occurrence.The purpose of this article is to provide new ideas,treatment,and target for diagnosis of RCC.Methods:1 To detect the relative expression quantity of RASSF10 gene,52 cases of RCC,paracancerous tissue and normal tissue was analysed by reverse transcription polymerase chain reaction(RT-PCR).And the relationship between RASSF10 mRNA relative expression in RCC and clicinal data was detected in the research.2 To detect the methylation state of RASSF10 gene,52 cases of RCC,paracancerous tissue and normal tissue was analysed by methylmion specific polymerase chain reaction(MSP).Meanwhile,this research aims to investigate the function of the RASSF10 gene methylation in development of RCC,and analyse the relationship between RASSF10 promoter methylation and clinical data.Results:1 To detect the methylation state of RASSF10 gene,52 cases of RCC,paracancerous tissue and normal tissue was analysed by methylmion specific polymerase chain reaction(MSP).And we found that there are three different methylation state:completely methylated,hemimethylated state and unmethylated state.2 To detect the relative expression quantity of RASSF10 gene,52 cases of RCC,paracancerous tissue and normal tissue was analysed by reverse transcription polymerase chain reaction(RT-PCR).The relative expression quantity of RASSF10 mRNA are 0.62±0.04,0.74±0.03,0.75±0.05.After statistical analysis,there is significant difference between the RCC group and normal tissue group(P<0.01),and the same as the RCC group and paracancerous tissue group.Although normal renal tissues group has a higher relative expression than that of paracancerous tissue,the difference between the two has no statistical significance(P > 0.05).3 In the 52 cases of RCC tissues,there was no significant difference between relative expression quantity of mRNA and gender(t=1.29,P=0.202),age(t=-1.94,0.060),pathological type(t=-1.54,P=0.131),tumor size(t=1.99,P = 0.052).(P > 0.05).4 The rate of RASSF10 gene methylation was 69.2%(36/52)in 52 cases of renal cell carcinoma.The rate of RASSF10 gene methylation was 36.5%(19/52)in 52 cases of paracancerous tissue.The rate of RASSF10 gene methylation was 25.0%(13/52)in 52 cases of normal tissue.Methylation rate of RCC tissue was higher than that in paracancerous tissue(?2=11.15,P = 0.001),and the methylation rate of RCC group was significantly higher than that in normal tissues(?2=20.41,P = 0.000),the difference was not statistically significant(P>0.05).The methylation rate of RASSF10 gene in male group was 69.7%(23/33),and the methylation rate of RASSF10 gene was 68.4%(13/19)in female group,the difference was not statistically significant(P>0.05).The rate of methylation of RASSF10 gene was 73.9%(17/23)in the 60 year old group,and the methylation rate of RASSF10 gene was 65.5%(19/29)in the age group over 60 years,the difference was not statistically significant(P>0.05).RASSF10 gene methylation rate was 68.3%(28/41)in the group of RCC,and the methylation rate of RASSF10 was 72.7%(8/11)in the group of non-clear cell carcinoma,the difference was not statistically significant(P>0.05).RASSF10 gene methylation rate was 68.6%(24/35)in the group of tumor size 7 cm or more,and the methylation rate was 70.6%(12/17)in the group of tumor size < 7 cm,the difference was not statistically significant(P>0.05).In Fuhrman stage,the methylation rate of RASSF10 was 62.5%(5/8)in well-differentiated group,the methylation rate of RASSF10 was 66.7%(16/24)in moderately differentiated group,the methylation rate of RASSF10 was 75.0%(15/20)in poorly differentiated group,the difference was not statistically significant(P>0.05).5 There was no significant difference between RASSF10 promoter methylation status and gender(?2= 0.01,P = 0.923),age(?2= 0.42,P = 0.514),pathological type(?2=0.08,P=0.78),and tumor size(?2 = 0.02,P = 0.882),Fuhrman stage(?2=0.56,P=0.757)(P > 0.05).And TNM stages of the tumor has a certain correlation(P < 0.05),while the tumor TNM staging Ⅲ-Ⅳ patients has a higher methylation rate than that ofⅠ-Ⅱ period(P = 0.043).6 In RCC tisues,the relative expression of RASSF10 in methylation group is lower than that in unmethylation group,and the difference was statistically significant between them(P<0.05).Conclusions:1 RASSF10 gene mRNA expression level in RCC tissue was reduced or missing,significantly lower than that of the corresponding expression in carcinoma and normal tissues.2 In RCC tissues,RASSF10 gene promoter methylation positive rate was significantly higher than that in paracancerous tissue and normal tissue.Moreover,TNM stage of tumor showed a significant correlation.3 The expression of RASSF10 gene mRNA in RCC tissues was reduced or absent,which was negative correlated with the promoter methylation status.RASSF10 gene promoter methylation may be involved in the occurrence of renal cell carcinoma. |
