Effects of 60 kDa prolactin and estradiol on metabolism and cell survival in cervical cancer: Co‑expression of their hormonal receptors during cancer progression

HPV and Cervical Cancer: Molecular and Immunological Aspects, Epidemiology and Effect of Vaccination in Latin American Women

Cervical cancer is primarily caused by Human Papillomavirus (HPV) infection and remains a significant public health concern, particularly in Latin American regions. This comprehensive narrative review addresses the relationship between Human Papillomavirus (HPV) and cervical cancer, focusing on Latin American women. It explores molecular and immunological aspects of HPV infection, its role in cervical cancer development, and the epidemiology in this region, highlighting the prevalence and diversity of HPV genotypes. The impact of vaccination initiatives on cervical cancer rates in Latin America is critically evaluated. The advent of HPV vaccines has presented a significant tool in combating the burden of this malignancy, with notable successes observed in various countries, the latter due to their impact on immune responses. The review synthesizes current knowledge, emphasizes the importance of continued research and strategies for cervical cancer prevention, and underscores the need for ongoing efforts in this field.

4SC-202 exerts an anti-tumor effect in cervical cancer by targeting PRLR signaling pathway

The aim of the present study is to investigate whether 4SC-202, a selective class I histone deacetylase inhibitor (HDACi), plays an anti-tumor role in cervical cancer (CC) by targeting prolactin receptor (PRLR). CCK-8 and colony formation assays were used to evaluate the effects of 4SC-202 on the proliferation of CC cells in vitro. Effects of 4SC-202 on the cell cycle distribution and apoptosis in SiHa cells were determined by flow cytometry and western blotting, respectively. Immunofluorescence, western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to detect the activities of PRLR-related pathways and PRLR expression in CC cells. A xenograft tumor model in nude mice was established to examine effects of 4SC-202 on the tumor growth, apoptosis and PRLR-related pathways in vivo. The biochemical analyzer and H&E staining were used to detect the serum biochemical indexes and organ toxicity. 4SC-202 inhibited the proliferation of CC cells (SiHa, HeLa, and CaSki) in vitro in a time- and dose-dependent manner. SiHa cells were treated with 1 or 5 µM 4SC-202 for 72 h and then subjected to various functional assays. The assays showed that 4SC-202 significantly induced G2/M phase arrest and apoptosis, while inhibiting the activities of PRLR-related pathways and PRLR expression. In addition, 4SC-202 reduced tumor growth and induced apoptosis in vivo. 4SC-202 down-regulated the expression of PRLR and activities of PRLR-related pathways in the mouse model, displayed no effects on serum biochemical indicators and caused no toxicity to mouse organs. This finding suggests that 4SC-202 may serve as a novel therapeutic agent for CC.

The Relevant Participation of Prolactin in the Genesis and Progression of Gynecological Cancers

Prolactin (PRL) is a hormone produced by the pituitary gland and multiple non-pituitary sites, vital in several physiological processes such as lactation, pregnancy, cell growth, and differentiation. However, PRL is nowadays known to have a strong implication in oncogenic processes, making it essential to delve into the mechanisms governing these actions. PRL and its receptor (PRLR) activate a series of effects such as survival, cellular proliferation, migration, invasion, metastasis, and resistance to treatment, being highly relevant in developing certain types of cancer. Because women produce high levels of PRL, its influence in gynecological cancers is herein reviewed. It is interesting that, other than the 23 kDa PRL, whose mechanism of action is endocrine, other variants of PRL have been observed to be produced by tumoral tissue, acting in a paracrine/autocrine manner. Because many components, including PRL, surround the microenvironment, it is interesting to understand the hormone's modulation in cancer cells. This work aims to review the most important findings regarding the PRL/PRLR axis in cervical, ovarian, and endometrial cancers and its molecular mechanisms to support carcinogenesis.

Expression and Role of the G Protein-Coupled Estrogen Receptor (GPR30/GPER) in the Development and Immune Response in Female Reproductive Cancers

Cancer is a major public health issue and represents the second leading cause of death in women worldwide, as female reproductive-related neoplasms are the main cause of incidence and mortality. Female reproductive cancers have a close relationship to estrogens, the principal female sex steroid hormones. Estrogens exert their actions by the nuclear estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). ERα, and ERβ act as transcription factors mediating genomic effects. Besides, the G protein-coupled estrogen receptor (GPER, formerly known as GPR30) was recently described as a seven-transmembrane receptor that mediates non-genomic estrogenic signaling, including calcium mobilization, cAMP synthesis, cleavage of matrix metalloproteinases, transactivation of epidermal growth factor receptor (EGFR), and the subsequent activation of PI3K and MAPK signaling pathways, which are the reasons why it is related to cellular processes, such as cell-cycle progression, cellular proliferation, differentiation, apoptosis, migration, and invasion. Since its discovery, selective agonists and antagonists have been found and developed. GPER has been implicated in a variety of hormone-responsiveness tumors, such as breast, endometrial, ovarian, cervical, prostate, and testicular cancer as well as lung, hepatic, thyroid, colorectal, and adrenocortical cancers. Nevertheless, GPER actions in cancer are still debatable due to the conflicting information that has been reported to date, since many reports indicate that activation of this receptor can modulate carcinogenesis. In contrast, many others show that its activation inhibits tumor activity. Besides, estrogens play an essential role in the regulation of the immune system, but little information exists about the role of GPER activation on its modulation within cancer context. This review focuses on the role that the stimulation of GPER plays in female reproductive neoplasms, specifically breast, endometrial, ovarian, and cervical cancers, in its tumor activity and immune response regulation.

17β‑estradiol‑induced mitochondrial dysfunction and Warburg effect in cervical cancer cells allow cell survival under metabolic stress

Mitochondria from different types of cancer show bioenergetics and dysfunction that favor cell proliferation. The mechanistic understanding of estrogen in cervical cancer is poorly understood. Therefore, the objective of this study was to determine how 17β-estradiol (E2) affects mitochondrial function and the Warburg effect in SiHa, HeLa and C33A cervical cancer cells. Mitochondrial compromise was evaluated measuring changes in the membrane permeability by immunofluorescence, calcium concentration, redox status, iron and ferritin reserves. Glucose consumption and lactic acid assays were used to detect the metabolic activity. Results were confirmed at molecular level by analysis of the differential gene expression using RNA sequencing. E2 modified the mitochondrial permeability and produced an alteration in the calcium signaling pathway. In HeLa and SiHa, there was a significant decrease in nitric oxide levels and lipid peroxidation, and an increase in glucose consumption and lactic acid levels when stimulated with E2. Intracellular iron or ferritin reserves were not affected by the E2 treatment. Genes differentially modulated by E2 were involved in the mitochondrial electron transport chain, oxidative phosphorylation system, glycolysis, pentose phosphate pathway and the regulation of metabolic signaling pathways. Herein, we provide evidence for a primary effect of estrogen on mitochondrial function and the Warburg effect, favoring the metabolic adaptation of the cervical cancer cell lines and their survival.

Interaction between 17β-estradiol, prolactin and human papillomavirus induce E6/E7 transcript and modulate the expression and localization of hormonal receptors

Background

Cervical cancer (CC) is the second most common cancer in less developed countries and the second leading cause of death by cancer in women worldwide. The 99% of CC patients are infected with the Human Papilloma Virus (HPV), being HPV16 and HPV18 infection the most frequent. Even though HPV is considered to be a necessary factor for the development of CC, it is not enough, as it requires the participation of other factors such as the hormonal ones. Several studies have demonstrated the requirement of estrogen and its receptors (ERα, ERβ, and GPER) in the precursor lesions progress towards CC. Also, prolactin (PRL) and its receptor (PRLR) have been associated with CC. The molecular mechanisms underlying the cooperation of these hormones with the viral oncoproteins are not well elucidated. For this reason, this study focused on analyzing the contribution of 17β-estradiol (E2), PRL, and HPV on the expression and localization of hormone receptors, as well as to evaluate whether these hormones may promote greater expression of HPV oncogenes and contribute to tumor progression.

Methods

qPCR was used to evaluate the effect of E2 and PRL on the expression of E6 and E7 oncoproteins in HeLa and SiHa cervical cancer cells lines. HaCaT cells were transduced with the viral oncogenes E6 and E7 from HPV 16 and 18. ERα, ERβ, GPER, and PRLR expression and localization were evaluated by qPCR, Western blot and immunofluorescence.

Results

E2 and PRL induce E6/E7 oncogenes expression in HeLa and SiHa cells. E6 and E7 oncogenes of HPV16/18 significantly increased the protein expression of ERα, GPER, and PRLR. ERβ was positively regulated only by E6 oncogenes of HPV16/18. Besides, some of these oncogenes modify the location of PRLR toward cytoplasm, and ERα, ERβ, and GPER mainly to the nucleus.

Conclusion

Our studies suggest that the mutual regulation between E2, PRL, and HPV oncogenes could cooperate with the carcinogenesis process in CC.