Possible involvement of the accessory sex glands in the regulation of pituitary hormones

Differential action of glycoprotein hormones: significance in cancer progression

Growth of multicellular organisms depends on maintenance of proper balance between proliferation and differentiation. Any disturbance in this balance in animal cells can lead to cancer. Experimental evidence is provided to conclude with special reference to the action of follicle-stimulating hormone (FSH) on Sertoli cells, and luteinizing hormone (LH) on Leydig cells that these hormones exert a differential action on their target cells, i.e., stimulate proliferation when the cells are in an undifferentiated state which is the situation with cancer cells and promote only functional parameters when the cell are fully differentiated. Hormones and growth factors play a key role in cell proliferation, differentiation, and apoptosis. There is a growing body of evidence that various tumors express some hormones at high levels as well as their cognate receptors indicating the possibility of a role in progression of cancer. Hormones such as LH, FSH, and thyroid-stimulating hormone have been reported to stimulate cell proliferation and act as tumor promoter in a variety of hormone-dependent cancers including gonads, lung, thyroid, uterus, breast, prostate, etc. This review summarizes evidence to conclude that these hormones are produced by some cancer tissues to promote their own growth. Also an attempt is made to explain the significance of the differential action of hormones in progression of cancer with special reference to prostate cancer.

A preliminary study on the possible role for luteinizing hormone in androgen independent growth of prostate

The recent observation that LH receptors are found in the prostate and that LH can execute a mitogenic role in addition to its well documented role in stimulation of steroidogenesis prompted the evaluation of the role of LH in regulation of prostate growth. The results obtained in the present study reveal the presence of LH receptor transcript as well as receptor protein in the rat prostate. The LH receptor appears to be localized in the non-secretory epithelial cells of the prostate as assessed by I(125) LH binding and immunofluorescence. Addition of HCG to purified prostate cells resulted in an increase in bromodeoxyuridine incorporation only in the non-secretory epithelial cells. Using a castrated adult rat model system, it has also been observed that LH receptor is regulated by LH itself, and that LH also regulates protein synthesis in the prostate. In addition, it has been possible to demonstrate the presence of LH receptor in the prostate from cases of human benign prostate hyperplasia. These results suggest a possible role for LH in the regulation of prostate growth.