Low levels of TSC22 enhance tumorigenesis by inducing cell proliferation in colorectal cancer

Transforming growth factor β-stimulated clone 22 domain 1 (TSC22) has been identified as a cancer suppressor gene in various kinds of cancers. The purpose of this study was to explore the expression of TSC22 in colorectal cancer (CRC) tissues and cell lines. 24 matched CRC and normal tissue samples by qPCR along with 18 pairs of them by Western blot demonstrated TSC22 level was decreased in CRC compared with normal tissue. The protein expression of TSC22 was examined in 310 CRC specimens. Results showed low expression of TSC22 was significantly correlated with tumor size (P = 0.048) and tumor infiltration (P = 0.016). Kaplan-Meier method suggested low expression of TSC22 was inversely associated with OS for 276 samples (P < 0.01). Multivariate Cox regression analysis confirmed TSC22 expression as independent predictors of the OS in CRC patients. Furthermore, we found TSC22 could suppress tumor by inhibiting cell proliferation in CRC cell lines.