ABSTRACT
Increasing evidences have shown that pregnant women might miscarry after exposure with environmental BaP (benzo(a)pyrene). Additionally, BPDE (benzo(a)pyren-7,8-dihydrodiol-9,10-epoxide), the ultimate metabolite of BaP, could induce dysfunctions of human trophoblast cells. However, it is rarely correlated between miscarriage and trophoblast dysfunctions. Moreover, their underlying mechanisms are still largely unidentified. In this study, a novel lncRNA (long non-coding RNA), lnc-HZ08, was identified to be highly expressed in human recurrent miscarriage (RM) tissues and in BPDE-treated human trophoblast cells. Lnc-HZ08 acts as a RNA scaffold to interact with both PI3K and its ubiquitin ligase CBL (Cbl proto-oncogene), enhances their protein interactions, and promotes PI3K ubiquitin degradation. In RM tissues and BPDE-treated trophoblast cells, DNA methylation level in lnc-HZ08 promoter region was reduced, which promotes estrogen receptor 1 (ER)-mediated lnc-HZ08 transcription. Subsequently, this upregulated lnc-HZ08 downregulated PI3K level, suppressed PI3K/p-AKT/p-P21/CDK2 pathway, and thus weakened proliferation, migration, and invasion of human trophoblast cells, which further induces miscarriage. These results may provide novel scientific and clinical insights in the occurrence of unexplained miscarriage. A novel lncRNA (lnc-HZ08) regulates the functions of human trophoblast cells and affects miscarriage. Lnc-HZ08 promotes PI3K ubiquitin degradation by enhancing CBL and PI3K interactions, downregulates PI3K/p-AKT/p-P21/CDK2 pathway, and weakens proliferation, migration, and invasion of trophoblast cells. BPDE exposure reduces the DNA methylation level in lnc-HZ08 promoter region and promotes estrogen receptor 1 (ER)-mediated lnc-HZ08 transcription. The suppressed PI3K/p-AKT/p-P21/CDK2 pathway regulated by increased lnc-HZ08 is associated with miscarriage. These results provide novel insights in the occurrence of unexplained miscarriage. Graphical Headlights ⢠Lnc-HZ08 downregulates PI3K/p-AKT/p-P21/CDK2 pathway to suppress proliferation, migration, and invasion of human trophoblast cells, and affects miscarriage. ⢠Lnc-HZ08 acts as a RNA scaffold to enhance the protein interaction of PI3K and its ubiquitin ligase CBL, which increases PI3K ubiquitination and degradation. ⢠Lnc-HZ08 transcription is associated with DNA methylation on its promoter region and transcription factor ER.
Subject(s)
Abortion, Spontaneous , RNA, Long Noncoding , 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide/metabolism , 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide/pharmacology , Abortion, Spontaneous/genetics , Abortion, Spontaneous/metabolism , Cell Movement , Estrogen Receptor alpha/metabolism , Female , Humans , Ligases/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Pregnancy , Proto-Oncogene Proteins c-akt/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Trophoblasts/metabolism , Ubiquitin/metabolismABSTRACT
BACKGROUND: Osteosarcoma (OS) is a refractory malignancy. This study aimed to explore the roles and mechanisms of Inhibin subunit beta A (INHBA) in OS. METHODS: INHBA expression levels in OS tissues and cells were assessed using RT-qPCR and western blotting. The impact of INHBA silencing on OS development was then explored by transfecting the OS cell lines U2OS and MG63 with INHBA-small interfering RNA (siRNA). The influence of INHBA silencing on U2OS and MG63 cell proliferation, migration, and invasion was examined using MTT and Transwell assays. Epithelial-mesenchymal transition (EMT) markers (E-cadherin and N-cadherin) were analyzed by RT-qPCR. The expression of genes involved in cell proliferation, migration, invasion, and the TGF-ß signaling pathway was evaluated by western blotting and RT-qPCR. RESULTS: INHBA levels were elevated in the OS tissues and cells. Furthermore, the transforming growth factor-ß (TGF-ß) signaling pathway of OS cells was suppressed in response to INHBA-siRNA, whereas proliferation, migration, and invasion of OS cells were inhibited. Besides, INHBA-siRNA significantly inhibited OS cell EMT, evidenced by enhanced E-cadherin mRNA expression and reduced N-cadherin mRNA expression. Further mechanistic studies revealed that the TGF-ß1 agonist SRI-011381 hydrochloride increased OS cell proliferation, migration, and invasion after INHBA downregulation. CONCLUSION: We found that INHBA silencing could play a vital role in OS via TGF-ß1-regulated proliferation, migration, and invasion.
Subject(s)
Bone Neoplasms , Osteosarcoma , Humans , Transforming Growth Factor beta1/metabolism , Signal Transduction/genetics , Gene Silencing , Osteosarcoma/pathology , RNA, Small Interfering/genetics , Cadherins/genetics , Cadherins/metabolism , Cell Proliferation/genetics , Bone Neoplasms/genetics , RNA, Messenger , Cell Movement/genetics , Cell Line, TumorABSTRACT
The oxysterol-binding protein-related protein (ORP) family is a group of proteins that mediate oxysterol metabolism and bioactivity in cells. ORPs constitute a large family of lipid transfer proteins. Much of the current evidence indicates that certain members of the family of oxysterol-binding proteins (OSBPs) can lead to cancer. Many studies have revealed the putative roles of OSBPs in various cancer types. However, the exact effects and mechanisms of action of members of the OSBP/ORP family in cancer initiation and progression are currently unclear. This review focuses on ORP family members that can accelerate human tumour cell proliferation, migration, and invasion. The mechanisms and functions of various ORPs are introduced in detail. We also attempt to identify the roles of these proteins in malignant tumours with the ultimate aim of determining the exact role of the OSBP/ORP family in human tumour cells.