TSPAN8 promotes colorectal cancer cell growth and migration in LSD1-dependent manner.

Aims: Colorectal cancer (CRC) is the fourth leading cause of cancer-related mortality worldwide. Over-expression of tetraspanin 8 (TSPAN8) is related to the development and progression of CRC. Whether TSPAN8 plays a role in the growth of colorectal cancer and its epigenetic mechanisms regulated by Lysine Specific Demethylase 1 (LSD1) are still unknown.

Main Methods: In this study, RT-PCR and western blotting were used to analyze the mRNA and protein expression, respectively; cell viability was assayed with MTS analysis; cell migration was measured with Trans-well analysis.

Key Findings: In the present study, the results indicated that the mRNA levels of LSD1 and TSPAN8 in CRC were significantly higher than that in corresponding adjacent non-tumor tissue. Down-regulation of LSD1 or TSPAN8 as well as LSD1 inhibitor Tranylcypromine hemisulfate inhibited the proliferation and migration of CRC cells, while over-expression of LSD1 exhibited opposite effects. LSD1 up-regulated TSPAN8 expression and reduced H3K9me2 occupancy on the TSPAN8 promoter in CRC cells. TSPAN8 promoted epithelial-mesenchymal transition (EMT) in CRC cells in LSD1-dependent manner.

Significance: TSPAN8 may be considered as a promising biomarker for the diagnosis and prognosis in patients with CRC. Furthermore, TSPAN8 could be a novel therapeutic target and potent LSD1 inhibitors could be designed and developed in the treatment of CRC.