Expression of lysophosphatidic acid acyltransferase beta (LPAAT-beta) in ovarian carcinoma: correlation with tumour grading and prognosis.

Lysophosphatidic acid acyltransferase beta (LPAAT-beta) is an enzyme involved in lipid biosynthesis whose role in tumour progression has been of emerging interest in the last few years. We investigated the expression of LPAAT-beta by reverse transcriptase-polymerase chain reaction and immunohistochemistry in 10 ovarian cell lines as well as in a cohort of 106 ovarian tumours and normal ovaries. Lysophosphatidic acid acyltransferase beta mRNA was found in all cell lines and ovarian tumours examined. Expression of LPAAT-beta protein was significantly increased in ovarian carcinomas compared to benign ovarian tissue (chi2 test P-value=0.001, Kruskal-Wallis test P-value <0.0001). Furthermore, LPAAT-beta expression was positively associated with higher tumour grade (P=0.044), higher mitotic index (P<0.0001) and tumour stage (P=0.032). Expression of LPAAT-beta was significantly linked to reduced overall survival time (P=0.024) as well as to shorter progression-free survival time (P=0.012) in patients younger than 60 years. Our study shows that LPAAT-beta is upregulated in ovarian cancer and is more prevalent in poorly differentiated tumours. In addition, LPAAT-beta expression is a predictor of a worse prognosis in patients younger than 60 years. Further studies are needed to investigate if LPAAT-beta may serve as a therapeutic target for certain subgroups of patients.