Prolactin (PRL) is a peptide hormone secreted by the anterior pituitary lobe. In addition to the pituitary, organs that secrete PRL include the mammary glands, prostate, brain, immune cells, and skin, regulating the metabolism of corresponding tissues through paracrine/autocrine mechanisms. Research has shown that besides regulating lactation and reproductive functions, PRL is also involved in the development of various tumors. Studies have confirmed high expression of PRL and prolactin receptor (PRLR) in breast cancer and prostate cancer, promoting tumor cell proliferation, angiogenesis, and chemotherapy resistance. PRL and PRLR expression have also been found in glioblastoma (GBM); in vitro experiments have shown that PRL can enhance migration and activation of GBM cells, and PRL overexpression promotes GBM cell proliferation.
