APOC1

APOC1 Full Name

apolipoprotein C-I

APOC1 Introduction

Apolipoprotein C-I (APOC1) is a small, exchangeable apolipoprotein primarily synthesized in the liver and a major component of plasma lipoproteins, enriched particularly in very-low-density lipoprotein (VLDL) and high-density lipoprotein (HDL). One of its core physiological functions is serving as a key regulator of lipid metabolism. Multiple studies have clearly established that APOC1 effectively inhibits the activity of lipoprotein lipase (LPL). By displacing LPL from the lipid/water interface of lipid droplets or lipoprotein particles, APOC1 prevents LPL from effectively binding to and hydrolyzing its substrate—triglycerides. This inhibition relies on the high affinity of APOC1 for lipid surfaces, sterically hindering LPL function. This mechanism is critical for regulating the catabolism of triglyceride-rich lipoproteins such as chylomicrons and VLDL, thereby influencing plasma triglyceride levels.

Figure 1. Schematic representation of the principal structural domains of apoC1. (Source: Fuior EV, et al. 2019)

Beyond its direct role in lipid metabolism, genetic variations in APOC1 are closely associated with cardiovascular disease risk. Genetic studies have shown that the single nucleotide polymorphism rs4420638 near the APOC1 gene locus is significantly linked to an increased risk of coronary artery disease (CAD).

More recently, research in oncology has uncovered novel pathophysiological roles for APOC1, with notable relevance in pancreatic cancer. Several studies report significant overexpression of APOC1 in aggressive pancreatic tumor tissues. Elevated APOC1 levels are observed not only in tumor tissue but also preoperatively in patient serum. Importantly, high APOC1 expression is strongly correlated with poor prognosis in pancreatic cancer patients, suggesting its potential as a prognostic biomarker. It is hypothesized that APOC1 may promote tumor progression by enhancing the invasive capacity of pancreatic cancer cells. Additionally, APOC1 has been found to be upregulated in other malignancies—including colorectal, renal, lung, and gastric cancers—where it similarly correlates with unfavorable clinical outcomes.

Alternate Names for APOC1

APOC1; apolipoprotein C-I; apo-CIB; apoC-IB; apolipoprotein C1;

• 1. Guo HH, et al. The roles, signalling pathways and therapeutic implications of Apoc1 in cancer. Discov Oncol. 2025 May 11;16(1):722.
  2. Fuior EV, et al. Apolipoprotein C1: Its Pleiotropic Effects in Lipid Metabolism and Beyond. Int J Mol Sci. 2019 Nov 26;20(23):5939.