The role of the prolactin receptor pathway in the pathogenesis of glioblastoma: What do we know so far?

Introduction: Prolactin (PRL) and its receptor (PRLR) have been associated with the development of hormone-dependent tumours and have been detected in glioblastoma (GBM) biopsies. GBM is the most common and aggressive primary brain tumour in adults and the prognosis for patients is dismal; hence researchers are exploring the PRLR pathway as a therapeutic target in this disease. Areas covered: This paper explores the effects of PRLR activation on the biology of GBM, the correlation between PRL and PRLR expression and GBM progression and survival in male and female patients. Finally, we discuss how an enhanced understanding of the PRLR pathway may allow the development of novel treatments for GBM. Expert opinion: We propose PRL and PRLR as potential prognosis biomarkers and therapeutic targets in GBM. Local administration of PRLR inhibitors using gene therapy may offer a beneficial strategy for targeting GBM cells disseminated in the non-neoplastic brain; however, efficacy and safety require careful and extensive evaluation. The data depicted herein underline the need to (i) improve our understanding of sexual dimorphism in GBM, and (ii) develop accurate preclinical models that take into consideration different hormonal contexts, specific genetic alterations and tumour grades.