Creatine kinase mitochondrial 2 promotes the growth and progression of colorectal cancer via enhancing Warburg effect through lactate dehydrogenase B

Mitochondrial creatine kinase (MtCK) plays a pivotal role in cellular energy metabolism, exhibiting enhanced expression in various tumors, including colorectal cancer (CRC). Creatine kinase mitochondrial 2 (CKMT2) is a subtype of MtCK; however, its clinical significance, biological functions, and underlying molecular mechanisms in CRC remain elusive.

In this study, we found the elevated expression of CKMT2 in CRC, and it was a robust prognostic indicator in CRC patients. CKMT2 regulates glucose metabolism via amplifying the Warburg effect through interaction with LDHB, which promotes the growth and progression of CRC. These insights unveil a novel regulatory mechanism by which CKMT2 influences CRC and provide promising targets for future CRC therapeutic interventions.

We employed immunohistochemical staining to discern the expression of CKMT2 in CRC and adjacent nontumor tissues of patients. The correlation between CKMT2 levels and clinical pathological factors was assessed. Additionally, we evaluated the association between CKMT2 and the prognosis of CRC patients using Kaplan-Meier survival curves and Cox regression analysis. Meanwhile, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression levels of CKMT2 in different CRC cell lines. Finally, we explored the biological functions and potential molecular mechanisms of CKMT2 in CRC cells through various techniques, including qRT-PCR, cell culture, cell transfection, western blot, Transwell chamber assays, flow cytometry, and co-immunoprecipitation.

We found that CKMT2 was significantly overexpressed in CRC tissues compared with adjacent nontumor tissues. The expression of CKMT2 is correlated with pathological types, tumor size, distant metastasis, and survival in CRC patients. Importantly, CKMT2 emerged as an independent prognostic factor through Cox regression analysis. Experimental downregulation of CKMT2 expression in CRC cell lines inhibited the migration and promoted apoptosis of these cells. Furthermore, we identified a novel role for CKMT2 in promoting aerobic glycolysis in CRC cells through interaction with lactate dehydrogenase B (LDHB).