Evaluation of the gene encoding carnitine transporter (OCTN2/SLC22A5) expression in human breast cancer and its association with clinicopathological characteristics.

Abstract

Fatty acid oxidation (FAO) is a major energy-generating process in the mitochondria and supports proliferation, growth, and survival of cancer cells. L-Carnitine is an essential co-factor for carrying long-chain fatty acids into the mitochondria. The entry of l-carnitine across cell membrane is regulated by OCTN2 (SLC22A5). Thus, it can plays a significant role in the mitochondrial fatty acid oxidation. This study aimed to evaluate the OCTN2 expression and its association with clinicopathological characteristics in breast cancer. In this work, OCTN2 was examined in 54 pairs of fresh samples of breast cancer (BC) and adjacent noncancerous tissue using quantitative real-time polymerase chain reaction and immunohistochemistry (IHC). The IHC approach was also used to investigate the expression of additional clinicopathological features. The present researchfindings revealed that the relative expression of OCTN2 in BC tissues was substantially higher than the adjacent normal tissues. This up-regulation was correlated positively with tumor size and Ki-67 and negatively with the progesterone receptor (PR) status, providing evidence of the opposite effects of OCTN2 and PR on tumor development. The studyshows that the OCTN2 expression in BC patients may be used as a prognostic biomarker and a tumor oncogene. As a result, it could be considered a possible therapeutic target. Nevertheless, the significance of the findings needs to be confirmed by further studies.