Obese postmenopausal women have an increased risk of breast cancer and are likely to have a worse prognosis than nonobese postmenopausal women. The cessation of ovarian function after menopause ...results in withdrawal of ovarian sex steroid hormones, estrogen, and progesterone. Accumulating evidence suggests that the withdrawal of estrogen and progesterone causes homeostasis imbalances, including decreases in insulin sensitivity and leptin secretion and changes in glucose and lipid metabolism, resulting in a total reduction in energy expenditure. Together with a decrease in physical activity and consumption of a high fat diet, these factors significantly contribute to obesity in postmenopausal women. Obesity may contribute to breast cancer development through several mechanisms. Obesity causes localized inflammation, an increase in local estrogen production, and changes in cellular metabolism. In addition, obese women have a higher risk of insulin insensitivity, and an increase in insulin and other growth factor secretion. In this review, we describe our current understanding of the molecular actions of estrogen and progesterone and their contributions to cellular metabolism, obesity, inflammation, and postmenopausal breast cancer. We also discuss how modifications of estrogen and progesterone actions might be used as a therapeutic approach for obesity and postmenopausal breast cancer.
Non-small cell lung cancer (NSCLC) accounts for the majority (80-85%) of all lung cancers. All current available treatments have limited efficacy. The epidermal growth factor receptor (EGFR) plays a ...critical role in the development and progression of NSCLC, with high EGFR expression associated with increased cell proliferation and poor prognosis. Thus, interfering with EGFR signaling has been shown to effectively reduce cell proliferation and help in the treatment of NSCLC. We previously demonstrated that the progesterone receptor (PR) contains a polyproline domain (PPD) that directly interacts with Src homology 3 (SH3) domain-containing molecules and expression of PR-PPD peptides inhibits NSCLC cell proliferation. In this study, we investigated whether the introduction of PR-PPD by cell-penetrating peptides (CPPs) could inhibit EGF-induced cell proliferation in NSCLC cells. PR-PPD was attached to a cancer-specific CPP, Buforin2 (BR2), to help deliver the PR-PPD into NSCLC cells. Interestingly, addition of BR2-2xPPD peptides containing two PR-PPD repeats was more effective in inhibiting NSCLC proliferation and significantly reduced EGF-induced phosphorylation of Erk1/2. BR2-2xPPD treatment induced cell cycle arrest by inhibiting the expression of cyclin D1 and CDK2 genes in EGFR-wild type A549 cells. Furthermore, the combination treatment of EGFR-tyrosine kinase inhibitors (TKIs), including Gefitinib or Erlotinib, with BR2-2xPPD peptides further suppressed the growth of NSCLC PC9 cells harboring EGFR mutations as compared to EGFR-TKIs treatment alone. Importantly, BR2-2xPPD peptides mediated growth inhibition in acquired Gefitinib- and Erlotinib- resistant lung adenocarcinoma cells. Our data suggests that PR-PPD is the minimal protein domain sufficient to inhibit NSCLC cell growth and has the potential to be developed as a novel NSCLC therapeutic agent.
Progesterone receptor (PR) isoforms, PRA and PRB, act in a progesterone-independent and dependent manner to differentially modulate the biology of breast cancer cells. Here we show that the ...differences in PRA and PRB structure facilitate the binding of common and distinct protein interacting partners affecting the downstream signaling events of each PR-isoform. Tet-inducible HA-tagged PRA or HA-tagged PRB constructs were expressed in T47DC42 (PR/ER negative) breast cancer cells. Affinity purification coupled with stable isotope labeling of amino acids in cell culture (SILAC) mass spectrometry technique was performed to comprehensively study PRA and PRB interacting partners in both unliganded and liganded conditions. To validate our findings, we applied both forward and reverse SILAC conditions to effectively minimize experimental errors. These datasets will be useful in investigating PRA- and PRB-specific molecular mechanisms and as a database for subsequent experiments to identify novel PRA and PRB interacting proteins that differentially mediated different biological functions in breast cancer.
•Roles of progesterone receptor (PR) and PR isoforms in lung neuroendocrine cells are not well understood.•In vitro, PRB expression significantly decreases lung neuroendocrine cell proliferation, ...independent of ligand.•PR and PRB immunolocalized to pulmonary endocrine cells in the fetal and adult lung.•In the fetal and adult lung, PRB expression is associated with a decrease in pulmonary neuroendocrine cell proliferation.
The progesterone receptor (PR) has been reported to play important roles in lung development and function, such as alveolarization, alveolar fluid clearance (AFC) and upper airway dilator muscle activity. In the lung, pulmonary neuroendocrine cells (PNECs) are important in the etiology and progression of lung neuroendocrine tumors (NETs). Women with lung NETs had significantly better survival rates than men, suggesting that sex steroids and their receptors, such as the PR, could be involved in the progression of lung NETs. The PR exists as two major isoforms, PRA and PRB. How the expression of different PR isoforms affects proliferation and the development of lung NETs is not well understood. To determine the role of the PR isoforms in PNECs, we constructed H727 lung NET cell models expressing PRB, PRA, Green Fluorescence Protein (GFP) (control). The expression of PRB significantly inhibited H727 cell proliferation better than that of PRA in the absence of progestin. The expression of the unrelated protein, GFP, had little to no effect on H727 cell proliferation. To better understand the role of the PR isoform in PNECs, we examined PR isoform expression in PNECs in lung tissues. A monoclonal antibody specific to the N-terminus of PRB (250H11 mAb) was developed to specifically recognize PRB, while a monoclonal antibody specific to a common N-terminus epitope present in both PRA and PRB (1294 mAb) was used to detect both PRA and PRB. Using these PR and PRB-specific antibodies, we demonstrated that PR (PRA&PRB) and PRB were expressed in the PNECs of the normal fetal and adult lung, with significantly higher PR expression in the fetal lung. Interestingly, PRB expression in the normal lung was associated with lower cell proliferation than PR expression, suggesting a distinct role of PRB in the PNECs. A better understanding of the molecular mechanism of PR and PR isoform signaling in lung NET cells may help in developing novel therapeutic strategies that will benefit lung NET patients in the future.
Sex steroid hormones, including estrogen, progesterone, and androgen, mediate their biological effects on cell proliferation, differentiation, and homeostasis through their respective nuclear ...receptors. In addition to functioning as ligand-activated nuclear transcription factors to regulate gene transcription, these receptors also have been shown to mediate rapid activation of non-genomic signaling pathways independent of their transcriptional activity. Despite the fact that non-genomic effects of sex steroids have been observed since more than three decades ago, the receptor mechanisms mediating these rapid effects still are not well understood. A subpopulation of nuclear steroid receptors localized to the cell membrane or cytoplasm has been proposed to mediate steroid hormone activation of signaling pathways; however, novel membrane receptors unrelated to nuclear receptors have also been implicated. This review focuses on recent advances in our understanding of the nature of the receptors and mechanisms responsible for rapid non-genomic signaling actions of sex steroids, including novel membrane receptors and interactions of nuclear steroid receptors with membrane and cytoplasmic signaling molecules such as adapter proteins, G proteins, ion channels, and protein kinases. A better definition of receptor mechanisms involved in mediating activation of non-genomic signaling pathways is important to our overall understanding of the biology of steroid hormones.
Tumor necrosis factor alpha (TNF-α) is a pro-inflammatory cytokine important in normal and pathological biological processes. Newly synthesized pro-TNF-α is expressed on the plasma membrane and ...cleaved to release soluble TNF-α protein: both are biologically active. Secreted TNF-α signals through TNF receptors and the membrane-bound TNF-α acts by cell contact-dependent signaling. Anti-TNF-α antibodies have been used effectively for treatment of chronic inflammation, however with adverse side effects. Thus, there is a need for new anti-TNF-α small molecule compounds. Anti-TNF-α activity assays involve treatment of keratinocytes with exogenous TNF-α before or after anti-TNF-α incubation. However, this model fails to address the dual signaling of TNF-α. Here we describe a Doxycycline (Dox)-inducible TNF-α (HaCaT-TNF-α) expression system in keratinocytes. Using this in-vitro model, we show cell inhibition and induced expression of pro-inflammatory cytokines and markers, including IL-1β, IL-6, IL-8, NF-κB1, and KRT-16, similar to cells treated with exogenous TNF-α. Sufficient secreted TNF-α produced also activated IL-1β and IL-8 expression in wt HaCaT cells. Importantly, stimulated expression of IL-1β and IL-8 in HaCaT-TNF-α were blocked by Quercetin, a flavanol shown to possess anti-TNF-α activities. This novel in vitro cell model provides an efficient tool to investigate the dual signaling of TNF-α. Importantly, this model provides an effective, fast, and simple screening for compounds with anti-TNF-α activities for chronic inflammatory disease therapies.
•Association sex steroid actions including estrogen, estrogen intracrinology, progesterone, hormone replacement therapy and androgen in NSCLC.•Association sex steroid receptor actions including ...estrogen receptor, progesterone receptor and androgen receptor in NSCLC.•Association sex steroid receptor signaling pathway in NSCLC.•The possible treatment of NSCLC patients by modulating sex steroid signaling.
Despite recent development in targeted therapies, lung cancer still remains the leading cause of cancer death. Therefore, a better understanding of its pathogenesis and progression could contribute to improving the eventual clinical outcome of the patients. Results of recently published several in vitro and clinical studies indicated the possible involvement of sex steroids in both development and progression of non-small cell lung carcinoma (NSCLC). Therefore we summarized the reported clinical relevant information of the sex steroids, their receptors and steroid metabolizing enzymes related to NSCLC in this mini-review. In addition, we also reviewed the potential “endocrine therapy”, targeting sex steroid actions and/or metabolism in NSCLC patients.
The instability of the protein expression in Pichia pastoris strains has been an issue for various peptide productions. Some modifications to the traditional fermentation process could potentially ...solve the problem. Here, we consider a four-stage fermentation process to express the CAP2 (cell-penetrating antimicrobial peptide 2) candidate in P. pastoris KM71H, a slow methanol utilization strain. During the fermentation process, CAP2 productivity is limited (6.15 ± 0.21 mg/L·h) by the low overall methanol consumption (approximately 645 g), which is mainly the result of the slow methanol utilization of the P. pastoris KM71H. To overcome this limitation, we increased the cell concentration two-fold prior to the induction stage. A fed-batch process with exponential and dissolved oxygen tension (DOT) stat feeding strategies was deployed to control the glycerol feed, resulting in an increase in cell concentration and enhancement of the volumetric methanol consumption rate. The improved fermentation process increased the overall methanol consumption (approximately 1070 g) and the CAP2 productivity (13.59 ± 0.24 mg/L·h) by 1.66 and 2.21 times, respectively. In addition, the CAP3 (cell-penetrating antimicrobial peptide 3) candidate could also be produced using this improved fermentation process at a high yield of 3.96 ± 0.02 g/L without any further optimization. Note that there was no oxygen limitation during the improved fermentation process operating at high cell density. This could be due to the controlled substrate addition via the DOT stat system.
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