Study On The Mechanism Of Estrogen And Estrogen Receptor In RCC Cells

Objective: Renal cell carcinoma(RCC)is a common tumor in urinary system,Because its early symptoms were not obvious,many patients have already had metastases in the diagnosis and cannot undergo surgical treatment.At the same time,RCC has a strong resistance to chemoradiotherapy,thus the effect of chemoradiotherapy was unsatisfied,and the targeted drug therapy can produce drug resistance,so an effective treatment method is urgently needed.And many studies had been carried out on its pathogenesis,gender and obesity are two important etiological factors.But the effect of estrogen(E2)on RCC has not been concluded.There was a significant difference in the incidence of RCC between different genders,and the prognosis of RCC patients was different in premenopausal and postmenopausal women,so we chose estrogen as the research object.In this study the role of estrogen and estrogen receptors(estrogen receptor,ER)played in the occurrence and development of RCC had been explored,and the correlation between estrogen-ER signaling pathways and insulin-like growth factor(insulin-like growth factor,IGF)family also had been studied,the effect of estrogen and estrogen receptors might occur in the development of RCC had been studied.Methods: Four types of human renal cancer cell lines(786-O,A498,ACHN,Caki-1)were cultured,and the ER expression was detected.The cell which had a high expression of ER was chosen as the research object.Cells were cultured by the culture medium adding estrogen and MTT assay was used to determine the effect of estrogen on the proliferation of RCC cells.In addition,different siRNAs were used for transfection of RCC cells,and the siRNA which had the best effect in the interfere of ER expression was chosen.Meanwhile,the expression of ER-? was downregulated by transfection of small interfering RNA.The transfected RCC cells were cultured with medium added estrogen.MTT assay was used to detect the cell proliferation after interference,to verify the effect of estrogen and ER-?on RCC cells.In addition,this study also determined the expression of IGF-1r in RCC cells under the influence of estrogen,to further clarified the mechanism of the effect of estrogen on RCC cells.Results :(1)Western blot was used to analyze the four RCC cell lines,the results showed that the expression of RE-? in 786-O cell line was the highest,and in the A498 was the lowest,ER-? expressed rarely in every cell lines.(2)The cells werecultured in a medium containing estrogen for 48 h,the growth of 786-O was significantly inhibited compared with the normal culture medium(p<0.05),while the growth of A498 was not significantly different from the normal culture medium.(3)After the application of siRNA to transfect 786-O to downregulate the expression of ER-?,cultured respectively with estrogen,fulvestrant(estrogen inhibitors),estrogen plus fulvestrant medium,results showed not transfection cell transfection cell proliferation was significantly inhibited(p < 0.05),and fulvestrant and fulvestrant +estrogen groups had no significant difference in the proliferation(p > 0.05).(4)Western blot was used to detect the above 3 groups cell,downregulation of ER-?,as well as fulvestrant,attenuated the stimulatory effect of estrogen on IGF-1R expression,suggesting a crosstalk between estrogen/ER-? and IGF axis.Conclusion: 1.In vitro cell experiments,estrogen played a role in inhibiting the growth of RCC cell line 786-O through ER-?.2.Estrogen may increase the expression of IGF-1r in RCC,indicating that estrogen and estrogen receptor are associated with IGF axis.