Overexpressed COL5A1 is correlated with tumor progression, paclitaxel resistance, and tumor‐infiltrating immune cells in ovarian cancer

Ovarian cancer (OC) remains the leading cause of cancer‐related death among gynecological cancers. The present study examined the role of collagen type V alpha 1 (COL5A1) and the characteristics of COL5A1 as an oncogenic protein in OC. The association of COL5A1 with paclitaxel (PTX)‐resistance and stemness in OC was also studied and the multidatabase and big data analyses of the prognostic value, coexpression network, genetic alterations, and tumor‐infiltrating immune cells of COL5A1 were elucidated. We found that COL5A1 expression was high in OC cells and tissues. Knockdown of COL5A1 inhibited the proliferation and migration of OC cells. Further study also showed that COL5A1 was overexpressed in PTX‐resistant OC cells compared to respective PTX‐sensitive cells. Additionally, COL5A1 was more enriched in OC stem cell‐like cells. Silencing COL5A1 expression decreased the OC cell resistance to PTX and inhibited the ability of OC‐spheroid formation. Survival analysis predicted that the elevated COL5A1 expression was associated with a worse survival outcome and correlated to the tumor stage of OC patients. The estimating relative subsets of RNA transcripts (CIBERSORT) algorithm analysis also unveiled the correlation of several tumor‐infiltrating immune cells with the expression of COL5A1. Taken together, our data demonstrate that COL5A1 is a biomarker to predict OC progression and PTX‐resistance and represents a promising target for OC treatment. 1) Collagen type V alpha 1 (COL5A1) is overexpressed in ovarian cancer (OC) and plays an oncogenic role in cancer cell proliferation, migration, and invasion. 2) COL5A1 acts as a paclitaxel resistance gene that participates in the regulation of the properties of OC stem cell‐like cells. 3) The association of COL5A1 with the genetic alteration, immune cell infiltration, and prognostic value indicates that COL5A1 may be a reliable biomarker and therapeutic target for OC patients.