A Novel Potential Prognostic Biomarker for Colorectal Cancer: TRPM7

Backgraund/Objectives: Transient receptor potential melastatin 7 (TRPM7), a unıque ion channel protein, has important effects for the proliferation of many cancer cell lines and tumor progression in various cancers. This study aimed to investigate whether TRPM7 expression has an effect on the prognosis of patients with colorectal cancer (CRC). Methods: TRPM7 expression was evaluated in paraffin-embedded tu-mor tissues of 259 CRC patients, immunohistochemically. In addition, the ratio of CD4+/CD8+ lymphocytes in the tumor microenvironment was determined semi-quantitatively. Results: According to our data, tumor size was clearly higher in cases with high TRPM7 expression than those with low expression. TRPM7 overex-pression was closely related to high depth of tumor invasion, increased lymph node metastasis and high distant metastasis rate. These findings exposed that high TRPM7 expression is effective in the progression and aggressiveness of CRC. While there was a negative correlation between TRPM7 overexpression and the density of CD8+ TILs, a positive correlation was revealed between TRPM7 expression and the CD4+/CD8+ TILs ratio. This result aroused curiosity for further studies on what kind of connection is between the TRPM7 channel protein and TILs. Also, high TRPM7 expression was closely associated with low overall (OS) and disease-free survival (DFS) times. Fur-thermore, multivariate analyses revealed TRPM7 overexpression was independently related with short OS and DFS. Conclusions: In conclusion, the high TRPM7 expres-sion and CD4+/CD8+ TILs ratio are independent poor prognostic indicators in CRC. In the future, TRPM7 may be a promising biomolecule for new targeted treatment options for CRC.