The prostate transmembrane protein, androgen-induced 1 (PMEPA1) has been previously shown to promote solid malignancies in a variety of cancers, but the role and mechanisms of PMEPA1 in breast cancer has not been fully addressed. Here, we found that PMEPA1 was upregulated in breast cancer cell lines as well as in a set of clinical invasive breast ductal carcinomas. Interestingly, depletion of PMEPA1 decreased breast cancer stem cell (CSC)-enriched populations, while ectopic overexpression of PMEPA1 increased breast CSC-enriched populations. Furthermore, transforming growth factor-β (TGF-β) treatment was also found to upregulate PMEPA1 expression and the CSCenriched populations in triple-negative breast cancer cell lines. TGF-β-induced PMEPA1 expression partially contributed to TGF-β-induced breast CSC maintenance. These findings suggest that TGF-β-PMEPA1 axis might provide new diagnosis and therapeutic targets for breast cancer treatment.
Much evidence suggests that immune imbalance in the lung plays a crucial role in the development of pulmonary fibrosis. Recently, all-trans retinoic acid (ATRA) shifting the regulatory T/T-helper 17 (Treg/Th17) profile had been proven in some diseases. However, to date, the effect of ARTA of pulmonary fibrosis has not been examined from this aspect. The objective of this study was to study the effect of ATRA on bleomycin-induced pulmonary fibrosis in mice and its possible mechanism. Pulmonary fibrosis was induced in C57BL/6 male mice by intratracheal instillation of bleomycin (5 mg.kg(-1)), which were randomly divided into control, bleomycin, and ATRA groups. Five mice in each group were sacrificed on day 28 after intratracheal instillation. Hemotoxylin and eosin (H&E) and Masson staining were used for pathological examination, and hydroxyproline in lung tissue was measured. Interleukin (IL)-17A protein expression was observed in lung with immunohistochemistry. The expression of IL-17A, IL-10, IL-6, and transforming growth factor (TGF)-β mRNAs were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Th17 and Treg expression in spleen lymphocytes were measured by flow cytometry. H&E and masson staining and expression of hydroxyproline showed that ATRA significantly alleviated lung fibrosis than in the bleomycin group. The expression of IL-17A, IL-10, IL-6, and TGF-β mRNAs were higher in the bleomycin group than in the normal group. ATRA can decrease these cytokines except for IL-10. CD4+CD25+ Treg cell ratio in the bleomycin group was significantly lower than normal, but CD4+IL-17+ T cells was higher; ARTA reversed this kind of expression. ATRA may ease the bleomycin-induced pulmonary fibrosis by inhibiting the expression of IL-6 and TGF-β, shifting the Treg/Th17 ratio and reducing the secretion of IL-17A.
Background: Interleukin (IL)-17-producing T lymphocytes play a role in pulmonary fibrosis, but the possible mechanism of IL-17 on lung fibroblasts remains uncertain. Objectives: To explore the role and possible mechanism of IL-17 on lung fibroblasts. Methods: A mouse model of pulmonary fibrosis was established by intratracheal administration of 5 mg/kg bleomycin. At 14 days following bleomycin administration the pulmonary fibroblasts were isolated, cultured and identified. siRNA for activator 1 (Act1) were transfected into lung fibroblasts, which were cocultured with IL-17. The NF-κB pathway was detected for IL-17 on the lung fibroblasts. Results: IL-17R was increased significantly at 14 days in the bleomycin-induced pulmonary fibroblast model, exogenous IL-17 significantly promoted the proliferation of the pulmonary fibroblasts in primary culture and obviously increased the expression of α-smooth muscle actin and type I and type III collagen in the fibroblasts. We found that IL-17 rapidly activated the NF-κB signaling pathway through activated phosphorylated p65 and IκB, and all roles of IL-17 on lung fibroblasts were inhibited under the interference for the expression of Act1 in lung fibroblasts. Conclusion: IL-17 may directly promote the proliferation, transformation and collagen synthesis of lung fibroblasts via the NF-kB signaling pathway, which can be inhibited by the interference for the expression of Act1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.