APOC2 accelerates colorectal cancer progression via modulating lipid metabolism and transcriptional activity of PHF8

The apolipoproteins (APOs) are the major proteins in blood lipid transportation. Emerging evidence has demonstrated that APOs might exert important function in tumor cells, but the underlying mechanism remains inclusive. In this study, we aim to explore the relationship between APOC2 dysfunction and colorectal cancer (CRC) malignancy. By analyzing the expression of APOC2 in 507 patients with CRC, we demonstrated that the APOC2 was overexpressed and associated with poor prognosis in CRC. We then found that high levels of APOC2 resulted in proliferation, invasion and metastasis of CRC cells in vitro and in vivo. Mechanistically, we revealed that APOC2 directly interacted with FASN which resulted in decreased levels of omega-3 fatty acids and increased levels of alpha-ketoglutarate (α-KG). Both RNA-seq and ChIP-seq analysis revealed that APOC2 overexpression resulted accumulation of α-KG leads to activation on the transcriptional program of PHF8 and thereby contributed to activation on genes involved in cell proliferation, invasion and metastasis. Together, our study unveiled the oncogenic role of APOC2 in tumor cells, which sheds new light on the potential of APOC2 as a biomarker in the prognosis of CRC.