HM13 is a predictive biomarker of metastasis and neutrophil infiltration in colorectal cancer.

Background: High levels of histocompatibility minor 13 (HM13) have been related to the progression of several cancers. Here, we investigated the function of HM13 in colorectal cancer (CRC).

Methods: HM13 expression, clinicopathology analysis, and its influence on survival were analyzed in multiple public databases (TCGA, TIMER2.0, and GEPIA). HM13 mRNA and protein levels in CRC cells were examined by qRT-PCR and western blot, respectively. CCK-8, Transwell, wound-healing, and adhesion assays were used to measure cell proliferation, migration, invasion, and adhesion in HM13-overexpressed and -silenced cells. The relationship between HM13 expression and neutrophil infiltration was also analyzed. CRC xenograft mouse models were used for in vivo verification of HM13 function.

Results: In this study, TCGA dataset analysis revealed that elevated HM13 levels correlated with malignant progression and worse survival outcomes in CRC. Cell migration, proliferation, invasion, and adhesion were suppressed through the knockdown of sh-HM13 and enhanced through HM13 overexpression. Additionally, HM13 expression significantly correlated with the infiltration level of neutrophils in CRC in TCGA and TIMER analyses. HM13 levels were also positively correlated with myeloperoxidase (MPO) levels. In addition, in vivo studies further confirmed that MPO overexpression partially abolished the inhibition of tumor growth by sh-HM13 in CRC.

Conclusion: The results suggested that high HM13 expression in CRC could promote tumor growth and metastasis by reducing neutrophil infiltration and may serve as a useful target in the treatment of metastatic CRC.