Fatty acid induced glioma cell growth is mediated by the acyl-CoA synthetase 5 gene located on chromosome 10q25.1-q25.2, a region frequently deleted in malignant gliomas.
Acyl-CoA synthetase (ACS) ligates fatty acid and CoA to produce acyl-CoA, an essential molecule in fatty acid metabolism and cell proliferation. ACS5 is a recently characterized ACS isozyme highly expressed in proliferating 3T3-L1 cells. Molecular characterization of the human ACS5 gene revealed that the gene is located on chromosome 10q25.1-q25.2, spans approximately 46 kb, comprises 21 exons and 22 introns, and encodes a 683 amino acid protein. Two major ACS5 transcripts of 2.5- and 3.7-kb are distributed in a wide range of tissues with the highest expression in uterus and spleen. Markedly increased levels of ACS5 transcripts were detected in a glioma line, A172 cells, and primary gliomas of grade IV malignancy, while ACS5 expression was found to be low in normal brain. Immunohistochemical analysis also revealed strong immunostaining with an anti-ACS5 antibody in glioblastomas. U87MG glioma cells infected with an adenovirus encoding ACS5 displayed induced cell growth on exposure to palmitate. Consistent with the induction of cell growth, the virus infected cells displayed induced uptake of palmitate. These results demonstrate a novel fatty acid-induced glioma cell growth mediated by ACS5.