Abstract
Colorectal cancer (CRC) treatment primarily relies on chemotherapy along with surgery, radiotherapy and, more recently, targeted therapy at the late stages. However, chemotherapeutic drugs have high cytotoxicity, and the similarity between the effects of these drugs on cancerous and healthy cells limits their wider use in clinical settings. Targeted monoclonal antibody treatment may compensate for this deficiency. Epidermal growth factor receptor (EGFR)‑targeted drugs have a positive effect on CRC with intact KRAS proto-oncogene GTPase (KRAS or KRASWT), but may be ineffective or harmful in patients with KRAS mutations (KRASMUT). Therefore, it is important to identify drug target genes that are uniformly effective with regards to KRASWT and KRASMUT CRC. The present study performed gene expression analysis, and identified 294 genes upregulated in KRASWT and KRASMUT CRC samples. Collagen type I α 1 (COL1A1) was identified as the hub gene through STRING and Cytoscape analyses. Consistent with results obtained from Oncomine, a cancer microarray database and web-based data-mining platform, it was demonstrated that the expression of COL1A1 was significantly upregulated in CRC tissues and cell lines regardless of KRAS status. Inhibition of COL1A1 in KRASWT and KRASMUT CRC cell lines significantly decreased cell proliferation and invasion. In addition, increased COL1A1 expression in CRC was significantly associated with serosal invasion, lymph metastases and hematogenous metastases. Taken together, the findings of the present study indicated that COL1A1 may serve as a candidate diagnostic biomarker and a promising therapeutic target for CRC.