The importance of lysophosphatidic acid in breast cancer

Breast cancer is the most common cancer in women and the second most common cause of cancer deaths after lung cancer. Autotaxin is identical to lysophospholipase D which catalyzes the lysophosphatidic acid production from lysophosphatidyl choline. Autotaxin has been shown to stimulate tumor progression, tumor cell motility and angiogenesis through the production of lysophosphatidic acid (LPA). Lysophosphatidic acid is a multifunctional phospholipid mediator. Lysophosphatidic acid acts through G protein coupled LPA receptors with a wide tissue distribution. The aim of this study was to investigate the importance of LPA in breast cancer by considering the relationship between serum autotaxin and lysophosphatidic acid levels, and the expression of LPA1 and LPA2 receptors in normal and breast cancer tissues. In this study, two groups formed: patients and control. Patients were divided into two groups according to lymph node status: patients with no lymph node involvement and patients with lymph node involvement. Autotaxin and LPA levels were measured in serum samples of control and patient groups individuals before the treatment. Lysophosphatidic acid receptors (LPA1 and LPA2) expression in breast cancer and normal tissues was shown by immunohistochemistry. Gamma glutamyl transferase (GGT) levels in node positive early stage patient group were significantly higher than the control and node negative early stage patient groups. Autotaxin level in both patient groups were significantly lower than the control group. Levels of LPA, glucose and calcium in node negative and node positive early stage patient groups were significantly higher than the control group. Levels of LPA in node positive early stage patient group were significantly higher than in node negative early stage patient group. As a result of logistic regression analysis, to distinguish the patient groups (both node negative and node positive early stage patient groups) from the control group, LPA was found to be an independent risk factor. LPA level was found to be correlated with stage of disease. LPA acts through LPA1 and LPA2 receptors in normal and breast cancer tissues. In conclusion, results of the present study suggest that LPA can be used as a marker for breast cancer diagnosis and follow-up