Expression and prognostic significance of MT1 isoforms in clear cell renal cell carcinoma

Metallothioneins (MTs), a family of low-weight cysteine-rich proteins, play key roles in tumor biology, such as proliferation, differentiation, apoptosis, and drug resistance. Clinical studies have demonstrated that deregulation of MTs in various types of solid cancers. However, a comprehensive overview of MT1 isoforms expression and clinical relevance in clear cell renal cell cancer (ccRCC) is lacking. The present study explored mRNA expression levels and prognostic values of MT1 isoforms in ccRCC tissues using The Cancer Genome Atlas (TCGA), Gene Expression Profiling and Interactive Analysis (GEPIA) and Oncomine database. The study observed that mRNA expression levels of six members of MT1 isoforms decreased in renal cancer tumor tissues compared with normal tissues. We further found that high-expression of MT1G, MT1H, MT1F and MT1X was related with poor overall survival time in ccRCC patients and high-expression of MT1G, MT1F and MT1X were inversely associated with disease-free survival time in ccRCC patients. Based on the correlation analysis, MT1G was identified to be co-expressed with MT1H and MT1F in ccRCC tissues. These findings suggested that MT1 isoforms mRNA may serve as diagnostic and prognostic markers for ccRCC.