Carbonic anhydrase 10 functions as a tumor suppressor in renal cell carcinoma and its methylation is a risk factor for survival outcome

Carbonic anhydrase 10 (CA10), one of the carbonic anhydrase isozymes, is explored to be downregulated in several tumor types, which indicates its critical role in tumorigenesis. However, its biologic and pathological function remains elusive in the pathogenesis of renal cell carcinoma (RCC). We examined expressions and functions of CA10 in RCC primary tumors and cell lines, assessed its tumor suppressive functions and further explored its impact on survival outcome of RCC patients. We found that CA10 was down-expressed in RCC primary tumors compared with adjacent non-malignant renal tissues. Promoter CpG methylation seemed to directly suppress the transcription of CA10 in RCC cells, which could be reversed by demethylation treatment. Restoration of CA10 in 786-O and Caki-2 cell lines inhibited their cell proliferation and promoted their apoptosis by regulating relevant apoptosis factors. Kaplan-Meier curve identified that CA10 methylation status was associated with progression-free survival in RCC (P = 0.021). Multivariate Cox regression analyses indicated the CA10 methylation status [HR, 4.724; 95% CI, 1.056–21.136; P = 0.042] was an independent predictor of disease progression. Collectively, our study demonstrates that CA10 as a tumor suppressor is frequently inactivated by promoter CpG methylation in RCC and its methylation is a risk factor for the prognosis of RCC.