Researchers found that a gene called KiSS-1, which normally helps stop cancer spread, is often turned off in colon cancer because its DNA gets extra chemical tags (methylation). This silencing shows up in tissue samples and is linked to worse tumor grades, higher chances of recurrence, and lower survival rates. While the findings improve how doctors might diagnose or predict colon cancer outcomes, they don’t give direct advice on using kisspeptin‑10 for health or performance purposes.

KISS1 is a metastasis suppressor lost in several solid malignancies. We evaluated the clinical relevance of KiSS-1 methylation and its protein expression in colorectal cancer. The epigenetic silencing of KiSS-1 by hypermethylation was tested in colon cancer cells (n = 5) before and after azacytidine treatment. KiSS-1 methylation was evaluated by methylation-specific PCR in colorectal cancer cells, and normal, benign, and tumor tissues (n = 352) were grouped in a training set (n = 62) and two independent validation cohorts (n = 100 and n = 190). KiSS-1 protein expression was analyzed by immunohistochemistry on tissue arrays. KiSS-1 hypermethylation correlated with transcript and protein expression loss, being increased in vitro by azacytidine. Methylation rates were 53.1, 70.0, and 80.0 % in the training and validation sets, respectively. In the training set, KiSS-1 methylation rendered a diagnostic accuracy of 72.7 % (p = 0.002). Combination of KiSS-1 methylation and serum CEA (p = 0.001) increased the prognostic utility of CEA alone (p = 0.022). In the first validation set, KiSS-1 methylation correlated with tumor grade (p = 0.011), predicted recurrence (p = 0.009), metastasis (p = 0.004), disease-free (p = 0.034), and overall survival (p = 0.015). In the second validation cohort, KiSS-1 methylation predicted disease-specific survival (p = 0.030). In the training set, cytoplasmic KiSS-1 expression was significantly higher in nonneoplastic biopsies as compared to colorectal tumors (p < 0.0005). In the validation set, loss of cytoplasmic expression correlated with tumor stage (p = 0.007), grade (p = 0.035), recurrence (p = 0.017), and disease-specific survival (p = 0.022). KiSS-1 was revealed epigenetically modified in colorectal cancer. The diagnostic and prognostic utility of KiSS-1 methylation and expression patterns suggests their assessment for the clinical management of colorectal cancer patients.