MicroRNA-377-3p inhibits hepatocellular carcinoma growth and metastasis through negative regulation of CPT1C-mediated fatty acid oxidation

Abstract

Background Altered lipid metabolism is closely related to the occurrence and development of hepatocellular carcinoma (HCC). Carnitine palmitoyltransferase 1C (CPT1C) is a member of CPT1 family and plays a key role in cancer development and progression. However, how microRNAs (miRNAs) regulate CPT1C-mediated fatty acid transport and oxidation remains to be elucidated. Methods Oil Red O staining, mitochondrial, and lipid droplets immunofluorescence staining were used to detect the functions of miR-377-3p and CPT1C in fatty acid oxidation. Colocalization of palmitate and mitochondria was performed to investigate the function of miR-377-3p and CPT1C in fatty acid transport into mitochondria. Fatty acid oxidation (FAO) assay was used to detect the function of miR-377-3p and CPT1C in FAO. Cell proliferation, migration and invasion assays and animal experiments were used to evaluate the role of miR-377-3p/CPT1C axis in HCC progression in vitro and in vivo. Immunofluorescence staining was used to identify the clinical significance of miR-377-3p and CPT1C in HCC patients. Results MiR-377-3p inhibits CPT1C expression by targeting its 3’-untranslated region. Through repression of CPT1C, miR-377-3p suppresses fatty acid oxidation by preventing fatty acid from entering into mitochondria and decreasing ATP production in HCC cells. Inhibiting fatty acid oxidation abolishes the ability of miR-377-3p/CPT1C axis to regulate HCC proliferation, migration, invasion and metastasis in vitro and in vivo. In HCC patients, CPT1C is significantly upregulated, and miR-377-3p expression and lipid droplets are negatively correlated with CPT1C expression. High expression of miR-377-3p and CPT1C predict better and worse clinical outcomes, respectively. Conclusions We uncover the key function and the relevant mechanisms of the miR-377-3p/CPT1C axis in HCC, which might provide a potential target for the treatment of HCC.

Bioinformatics analysis and experimental verification of the prognostic and biological significance mediated by fatty acid metabolism related genes for hepatocellular carcinoma

“…FA metabolism has been shown to play a key role in the onset and progression of HCC ( 39 ). Most research focused only on a single regulatory factor of FA metabolism in HCC ( 10 , 29 , 45 ), however, integrated models of multiple important genes involved in FA metabolism are needed. He et al.…”

“…FA metabolism has been shown to play a key role in the onset and progression of HCC (39). Most research focused only on a single regulatory factor of FA metabolism in HCC (10,29,45), however, integrated models of multiple important genes involved in FA metabolism are needed. He et al had explored FA metabolism-related risk genes in HCC by constructing a prognostic model but failed to further explore the role of these genes in the onset and progression of HCC (46).…”

“…A flow chart of the overall research is shown in Figure S1. 30 genes were chosen based on their roles in previous studies (27)(28)(29)(30)(31)(32)(33). The majority of FA metabolism-related genes were identified as DEGs (p < 0.05) using Heatmap analysis (Figure 1A).…”

Mitochondrial Dysfunction and Chronic Liver Disease

“…The above studies indicate that mitochondrial dysfunction is involved in the occurrence and development of HCC, and mitochondria might be a therapeutic target for HCC. This was demonstrated by Zhang [ 56 ] and Tussy [ 57 ] et al, in studies on microRNA (miRNA) targeting mitochondria involved in HCC progression. In the course of treatment for HCC, drugs induced apoptosis and exerted an anti-cancer effect by inhibiting ATP synthesis, promoting increases in the ROS levels, and decreasing the MMP.…”

“…[ [54][55][56] ROS During the development of HCC, ROS is increased. [50,51] mtDNA mtDNA is damaged by ROS, resulting in mitochondrial gene mutation.…”