The bladder cancer (BCa) microenvironment comprises heterogeneous tumor cell populations, the surrounding stroma and the extracellular matrix (ECM). Collagen, the scaffold of the tumor microenvironment, regulates ECM remodeling to promote tumor infiltration, angiogenesis, invasion and migration. The present study examined how collagen type VI‑α (COL6A) 1 and 2 function during BCa pathogenesis and progression, with the aim of facilitating the development of precision therapeutics, risk stratification and molecular diagnosis. COL6A1 and COL6A2 mRNA expression in non‑muscle invasive BCa (NMIBC) and MIBC tissue samples was measured using reverse transcription‑quantitative PCR. In addition, the tumor‑suppressive effects of COL6A1 and COL6A2 in human BCa EJ cells (MGH‑U1) were assessed. Compared with normal controls, COL6A1 and COL6A2 mRNA expression was downregulated in both NMIBC and MIBC tissue samples (P<0.05, respectively). COL6A1 and COL6A2 effectively inhibited the proliferation of human BCa EJ cells (MGH‑U1) and induced cell cycle arrest at the G1 phase. Additionally, COL6A1 and COL6A2 served roles in MAPK and AKT signaling by increasing p38 MAPK phosphorylation and decreasing AKT phosphorylation. Finally, COL6A1 and COL6A2 inhibited wound healing and invasion by suppressing the activity of matrix metalloproteinase (MMP)‑2 and MMP‑9. In conclusion, COL6A1 and COL6A2 may act as classical collagens by forming a physical barrier to inhibit BCa tumor growth and invasion.
Keywords: BCa; COL6A; pathogenesis; progression; tumor suppressor.