Receptor gene messenger RNA expression in metastatic lesions of prostate cancer

There are hardly any options for treating hormone refractory prostate cancer. Some groups have already suggested antitumor therapy of prostate cancer using agonists, antagonists or other concepts acting on luteinizing hormone-releasing hormone (LH-RH) receptor. Few studies have been published to date on the detection of LH-RH receptors in human prostate cancer tissue. However, at this point it is completely unclear in this context whether metastasizing prostate cancer lesions, which may be major potential targets of a type of therapy, have any LH-RH receptors. In this study we examined tumor samples of lymph nodes from patients with prostate cancer obtained during radical prostatectomy and laparoscopic lymphadenectomy for the expression of LH-RH receptor messenger (m)RNA.

Multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) was done to detect the expression of the mRNA of LH-RH receptor, prostate specific antigen and beta-actin in pelvic lymph nodes from 100 patients with prostate cancer.

In 27 patients at least 1 histopathological metastasis (19) and/or positive RT-PCR for prostate specific antigen (22) was identified. In 7 of these patients (25.9%) RT-PCR revealed LH-RH mRNA expression.

To our knowledge our study shows for the first time a rather low incidence of LH-RH receptor mRNA in primary pelvic lymph node metastases. However, since other studies show that an increased incidence of LH-RH receptors is typical of the hormone refractory stage of the disease, further studies in this specific patient population may help explain the clinical importance of LH-RH receptors in the development of new therapeutic approaches to advanced prostate cancer.