Differential action of glycoprotein hormones: significance in cancer progression

Abstract

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.

Fig. 1

Regulation of rat Leydig cell proliferation by LH

Fig. 2

Differential in vitro response to LH on testosterone production in rat Leydig cells. Purified Leydig cells were isolated from immature and adult rats and cells from each group were incubated under in vitro condition in the presence or absence of LH/hCG for 4 h at 34 °C as described earlier [26]. Testosterone was estimated by specific Radioimmuno assay (RIA)

Fig. 3

Regulation of rat Sertoli cell proliferation by FSH

Fig. 4

Thyroid stimulating hormone receptor (TSHR) in human breast cancer tissue