The role of prolactin and its receptor in cancer development

Abstract

Prolactin (PRL) is a peptide hormone which regulates various processes in the body. It takes part in mammary gland development, regulation of lipid, and carbohydrate metabolism. Expression of a gene encoding PRL was observed in the pituitary gland, in the mammary gland, immune system cells, and adipose tissue. A serum level of PRL depends on many factors, for instance the time of day, sex, levels of various hormones, and stress. Posttranslational modifications result in the appearance of vasoinhibins, characterized by different biological features than in the primary hormone molecule. Elevated levels of prolactin in plasma are associated with hyperprolactinemia. Prolactin receptor (PRLR) is found on the surface of many cells of normal tissues. Its presence can also be detected in various types of cancer cells. The issue of the roles of PRL and prolactin receptor (PRLR) is worthy of attention, because of their contribution to the regulation of normal metabolic processes and their part in cancer development. Among diseases in which PRL or PRLR have an influence on their progression, breast cancer, prostate cancer or colorectal cancer can be found. As prolactin and its receptor take part in cancer initiation and progression, these molecules have a potential to become a good therapeutic target. The aim of this review is to summarize and systemize the knowledge on the subject of the roles of PRL and PRLR in cancerogenesis.