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[Display omitted] Nano-Pt induces autophagy through PI3K/AKT/mTOR and P53/mTOR pathways, and also promotes apoptosis, thereby killing osteosarcoma cells. • The prognosis and chemotherapy of osteosarcoma need to be improved. • Platinum-based drugs improved by nanotechnology are promising. • Nano-Pt has shown therapeutic effects in a variety of cancers. • Nano-Pt has a wide range of therapeutic effects on three types of osteosarcoma cells. • Nano-Pt has two mechanisms to promote autophagy on cells with different P53 status. The enhancement of platinum-based chemotherapeutic agents utilizing nanotechnology holds promise for improving the prognosis of osteosarcoma chemotherapy in the context of a focus on autophagy. This study aims to examine the correlation and potential mechanisms between novel nano-platinum (Nano-Pt), osteosarcoma, and autophagy at both the cellular and animal levels. This study investigated the impact of Nano-Pt on the malignant biological behavior of three osteosarcoma cell lines (MG-63, U2-OS, and 143B), which was subsequently confirmed through animal experimentation. Furthermore, the association between Nano-Pt and PI3K/AKT/mTOR, P53/mTOR, and autophagy pathways was examined in diverse osteosarcoma cells. Utilizing confocal microscopy and transmission electron microscopy, it was observed that Nano-Pt possesses the capability to enter osteosarcoma cells. It was demonstrated that Nano-Pt exhibits a substantial inhibitory impact on proliferation, migration, and clone formation, while concurrently inducing apoptosis. The anticancer efficacy of Nano-Pt in vivo, as well as its lower normal cellular and tissue toxicity, were further substantiated through animal experimentation. Through rescue experiments based on autophagy inhibitor (3-MA) and mTOR agonist (MHY1485), mRFP-GFP-LC3 autophagic flux detection, TEM autophagosome observation, autophagy and apoptosis-related Western blotting, and apoptosis flow cytometry confirmed the ability of Nano-Pt to promote autophagy and apoptosis. It was revealed that Nano-Pt promotes autophagy through different pathways in cells with different P53 expression patterns. Nano-Pt demonstrated inhibition of cell proliferation and migration, as well as promotion of apoptosis, in all three types of osteosarcoma cells. Moreover, Nano-Pt induced autophagy mediated by the PI3K/AKT/mTOR pathway in MG-63 cells, while activating autophagy mediated by the P53/mTOR pathway and PI3K/AKT/mTOR pathway in U2-OS and 143B cells. [ABSTRACT FROM AUTHOR]

Background: Epithelial ovarian cancer (OC) is the fourth leading cause of cancer-related deaths in women, with a 5-year survival rate of 30%-50%. Platinum resistance is the chief culprit for the high recurrence and mortality rates. Several studies confirm that the metabolic regulation of ubiquitinating enzymes plays a vital role in platinum resistance in OC. Methods: In this study, we selected ubiquitin-conjugating enzyme E2S (UBE2S) as the candidate gene for validation. The levels of UBE2S expression were investigated using TCGA, GTEx, UALCAN, and HPA databases. In addition, the correlation between UBE2S and platinum resistance in OC was analyzed using data from TCGA. Cisplatin-resistant OC cell lines were generated and UBE2S was knocked down; the transfection efficiency was verified. Subsequently, the effects of knockdown of UBE2S on the proliferation and migration of cisplatin-resistant OC cells were examined through the CCK8, Ki-67 immunofluorescence, clone formation, wound healing, and transwell assays. In addition, the UBE2S gene was also validated in vivo by xenograft models in nude mice. Finally, the relationship between the UBE2S gene and autophagy and the possible underlying regulatory mechanism was preliminarily investigated through MDC and GFP-LC3-B autophagy detection and western blotting experiments. Most importantly, experimental validation of mTOR agonist reversion (the rescuse experiments) was also performed. Results: UBE2S was highly expressed in OC at both nucleic acid and protein levels. The results of immunohistochemistry showed that the level of UBE2S expression in platinum-resistant samples was significantly higher relative to the platinum-sensitive samples. By cell transfection experiments, knocking down of the UBE2S gene was found to inhibit the proliferation and migration of cisplatin-resistant OC cells. Moreover, the UBE2S gene could inhibit autophagy by activating the PI3K/AKT/mTOR signaling pathway to induce cisplatin resistance in OC in vivo and in vitro. Conclusion: In conclusion, we discovered a novel oncogene, UBE2S, which was associated with platinum response in OC, and examined its key role through bioinformatics and preliminary experiments. The findings may open up a new avenue for the evaluation and treatment of OC patients at high risk of cisplatin resistance. [ABSTRACT FROM AUTHOR]

The role of Meg3 in the proliferation of atRA-treated mouse embryonic palate mesenchymal cells involved the Smad pathway. [Display omitted] • MEPM-cell proliferation is regulated by atRA and exogenous TGF-β3. • The inhibition of Smad signaling is related to the reduction of MEPM-cell proliferation. • atRA enhance LncRNAMeg3 expression in MEPM cells. • Meg3 participates in the atRA-induced suppression of MEPM-cell proliferation. • Meg3 targets Smad2 and thereby mediates the TGF-β/Smad signaling inhibition. Mesenchymal cell proliferation is critical for the growth of the palate shelf. All-trans retinoic acid (atRA), as well as pathways associated with TGF-β/Smad signaling, play crucial roles in the proliferation of mouse embryonic palate mesenchymal (MEPM) cells. We have found that MEPM-cell proliferation was regulated by atRA and exogenous TGF-β3 could significantly antagonize the atRA-mediated suppression of MEPM cell proliferation, which is closely associated with the regulation of TGF-β/Smad signaling pathway. The long non-coding RNA (lncRNA) MEG3 has been reported to activate TGF-β/Smad signaling, thereby regulating cellular proliferation, differentiation, and related processes. Here, we found that Meg3 expression increased significantly in atRA-treated MEPM cells while TGF-β3 treatment markedly inhibited Meg3 expression and antagonized the effect of atRA on Meg3. Moreover, Smad2 was found to interact directly with Meg3, and atRA treatment significantly enriched Meg3 in Smad2-immunoprecipitated samples. After Meg3 deletion, the effects of atRA on the proliferation of MEPM cells and TGF-β3-dependent protein expression were lost. Hence, we speculate that Meg3 has a role in the RA-induced suppression of MEPM cell proliferation by targeting Smad2 and thereby mediating TGF-β/Smad signaling inhibition. [ABSTRACT FROM AUTHOR]

The role of LncRNA Meg3 in atRA-induced cleft palate involved the Smad pathway. • All-trans retinoic acid (atRA) enhanced Meg3 expression in MEPM cells. • Meg3 was linked to the suppression of MEPM cell proliferation. • AtRA treatment was associated with the demethylation of CpG sites in the Meg3 promoter. • Smad2 is a Meg3 target in the context of atRA-induced cleft palate. Palatal mesenchymal cell proliferation is essential to the process of palatogenesis, and the proliferation of mouse embryonic palate mesenchymal (MEPM) cells is impacted by both all-trans retinoic acid (atRA) and the TGF-β/Smad signaling pathway. The long non-coding RNA (lncRNA) MEG3 has been shown to activate TGF-β/Smad signaling and to thereby regulate cell proliferation, differentiation, and related processes. Herein, we found that atRA treatment (100 mg/kg) promoted Meg3 upregulation in MEPM cells, and that such upregulation was linked to the suppression of MEPM cell proliferation in the context of secondary palate fusion on gestational day (GD) 13 and 14. Moreover, the demethylation of specific CpG sites within the lncRNA Meg3 promoter was detected in atRA-treated MEPM cells, likely explaining the observed upregulation of this lncRNA. Smad signaling was also suppressed by atRA treatment in these cells, and RNA immunoprecipitation analyses revealed that Smad2 can directly interact with Meg3 in MEPM cells following atRA treatment. Therefore, we propose a model wherein Meg3 is involved in the suppression of MEPM cell proliferation, functioning at least in part via interacting with the Smad2 protein and thereby suppressing Smad signaling in the context of atRA-induced cleft palate. [ABSTRACT FROM AUTHOR]

• HOTAIR expression was increased in cholangiocarcinoma. • HOTAIR deletion inhibited cholangiocarcinoma progression. • HOTAIR upregulated HMGB1 expression by sponging miR-204-5p. • HOTAIR promoted cholangiocarcinoma progression via miR-204-5p/HMGB1 axis. Cholangiocarcinoma (CCA) is a malignant tumor in the world. LncRNA HOX transcript antisense intergenic RNA (HOTAIR) was identified as a crucial regulator in various cancers including CCA. This study aimed to unravel the functions of HOTAIR and its biological mechanism in CCA, hinting for the new therapeutic targets in CCA. The levels of HOTAIR, miR-204-5p and HMGB1 in CCA tissues and cell lines (HuB28 and HuCCT1) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was conducted to detect the protein levels of LC3-I, LC3-II, Beclin-1 and HMGB1. The relationships among HOTAIR, miR-204-5p and HMGB1 were examined by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull down assay. Cell proliferation ability and apoptosis rate were assessed by CCK8 assay and flow cytometry, respectively. in vivo experiment was conducted to examine the bio-functions of HOTAIR in nude mice. HOTAIR and HMGB1 were over-expressed, while miR-204-5p was lowly expressed in CCA tissues and cells. The dual-luciferase reporter assay indicated that miR-204-5p was a target of HOTAIR, and HMGB1 was a target of miR-204-5p. The restoration experiments showed that HOTAIR repressed cell apoptosis, autophagy and promoted cell proliferation via miR-204-5p/HMGB1 axis. Additionally, HOTAIR silencing retarded the xenograft tumor growth by up-regulation of miR-204-5p and down-regulation of HMGB1. These data unraveled that lncRNA HOTAIR regulated HMGB1 to suppress cell apoptosis, autophagy and induce cell proliferation by sponging miR-204-5p in CCA. Thus, this new regulatory pathway may provide new therapeutic targets for CCA. [ABSTRACT FROM AUTHOR]