Hsa_circ_0005085 may suppress cutaneous squamous cell carcinoma growth and metastasis through targeting the miR-186-5p/LAMC1 axis.

BACKGROUND: Cutaneous squamous cell carcinoma (CSCC) is a severe malignancy derived from the skin. Mounting evidence suggests that circular RNAs (circRNAs) participate in diverse biological functions in human cancers, containing CSCC. However, the biological functions and underlying mechanism of hsa_circ_0005085 in CSCC have not been clearly studied. METHODS: Expression levels of hsa_circ_0005085, microRNA-186-5p (miR-186-5p), and Laminin subunit gamma 1 (LAMC1) were detected by reverse transcription-quantitative polymerase chain reaction. Cell counting kit-8 assay, colony formation assay, and 5-Ethynyl-2'-deoxyuridine assay were used to assess cell proliferation. Transwell assay was conducted to detect cell migration and invasion. Cell apoptosis was analyzed by flow cytometry. Protein expression of LAMC1, E-cadherin, Snail, and slug were assessed using western blot assay. Using bioinformatics software, the binding between miR-186-5p and hsa_circ_0005085 or LAMC1 was predicted, followed by verification using a dual-luciferase reporter and RNA-Immunoprecipitation. The mouse xenograft model was established to investigate the role of hsa_circ_0005085 in vivo. RESULTS: Hsa_circ_0005085 level was downregulated in CSCC tissues and cells. Overexpression of hsa_circ_0005085 inhibited cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and promoted cell apoptosis in CSCC. MiR-186-5p could restore the effect of hsa_circ_0005085 overexpression on CSCC cells, and the knockdown of LAMC1 reversed the regulation of the miR-186-5p inhibitor. In mechanism, hsa_circ_0005085 served as a sponge for miR-186-5p to regulate LAMC1 expression. Overexpression of hsa_circ_0005085 reduced growth of tumor via miR-186-5p/LAMC1 axis in vivo. CONCLUSION: In our study, hsa_circ_0005085 might inhibit CSCC development by targeting the miR-186-5p/LAMC1 axis, which might provide a promising therapeutic target for CSCC.

SARS-CoV-2 ORF3a positively regulates NF-κB activity by enhancing IKKß-NEMO interaction.

Coronavirus disease 2019 (COVID-19) is a global pandemic caused by SARS-CoV-2 infection. Patients with severe COVID-19 exhibit robust induction of proinflammatory cytokines, which are closely associated with the development of acute respiratory distress syndrome. However, the underlying mechanisms of the NF-κB activation mediated by SARS-CoV-2 infection remain poorly understood. Here, we screened SARS-CoV-2 genes and found that ORF3a induces proinflammatory cytokines by activating the NF-κB pathway. Moreover, we found that ORF3a interacts with IKKß and NEMO and enhances the interaction of IKKß-NEMO, thereby positively regulating NF-κB activity. Together, these results suggest ORF3a may play pivotal roles in the pathogenesis of SARS-CoV-2 and provide novel insights into the interaction between host immune responses and SARS-CoV-2 infection.

Circular RNA circ-LARP1B contributes to cutaneous squamous cell carcinoma progression by targeting microRNA-515-5p/TPX2 microtubule nucleation factor axis.

Circular RNAs (circRNAs) have shown pivotal regulatory roles in tumorigenesis and progression. Our purpose was to analyze the role of circRNA La ribonucleoprotein 1B (circ-LARP1B; hsa_circ_0070934) in cutaneous squamous cell carcinoma (CSCC) progression and its associated mechanism. Cell viability, colony formation ability, migration, and invasion were analyzed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide (MTT) assay, colony formation assay, wound healing assay, and transwell invasion assay. Flow cytometry was performed to analyze cell apoptosis and cell cycle progression. Cell glycolytic metabolism was analyzed using Glucose Uptake Colorimetric Assay kit, Lactate Assay Kit II, and ATP colorimetric Assay kit. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to verify the interaction between microRNA-515-5p (miR-515-5p) and circ-LARP1B or TPX2 microtubule nucleation factor (TPX2). Circ-LARP1B expression was up-regulated in CSCC tissues and cell lines. Circ-LARP1B knockdown suppressed cell viability, colony formation ability, migration, invasion, cell cycle progression, and glycolysis and triggered cell apoptosis in CSCC cells. miR-515-5p was a direct target of circ-LARP1B in CSCC cells, and circ-LARP1B silencing-mediated anti-tumor effects were largely counteracted by miR-515-5p knockdown. miR-515-5p directly interacted with the 3' untranslated region (3'UTR) of TPX2. TPX2 overexpression largely overturned miR-515-5p-mediated anti-tumor effects in CSCC cells. Circ-LARP1B could up-regulate TPX2 expression by sponging miR-515-5p in CSCC cells. Circ-LARP1B knockdown suppressed tumor growth in vivo. In conclusion, circ-LARP1B contributed to CSCC progression by targeting miR-515-5p/TPX2 axis. The circ-LARP1B/miR-515-5p/TPX2 axis might provide novel therapeutic targets for CSCC patients.

Alisertib promotes apoptosis and autophagy in melanoma through p38 MAPK-mediated aurora a signaling.

We investigated the efficacy of Alisertib (ALS), a selective Aurora kinase A (AURKA) inhibitor, in melanoma. We found that ALS exerts anti-proliferative, pro-apoptotic, and pro-autophagic effects on A375 and skmel-5 melanoma cells by inhibiting p38 MAPK signaling. SB202190, a p38 MAPK-selective inhibitor, enhanced ALS-induced apoptosis and autophagy in both cell lines. ALS induced cell cycle arrest in melanoma cells through activation of the p53/p21/cyclin B1 pathway. Knockdown of p38 MAPK enhanced ALS-induced apoptosis and reduced ALS-induced autophagy. Inhibition of autophagy sensitized melanoma cells to ALS-induced apoptosis. These data indicate ALS is a potential therapeutic agent for melanoma.

[Effect of Doxorubicin on abcb4 Gene Expression in Zebrafish (Danio rerio) Embryos].

OBJECTIVE: To determine the effect of doxorubicin (DOX) on abcb4 gene expression and the role of abcb4 gene in multidrug-resistance. METHODS: Zebrafish embryos were treated with 2 mL/L DMSO, 10 µmol/L DOX and 2 mL/L DMSO+10 µmol/L DOX, respectively. The zebrafish embryos treated with Eggwater served as controls. Exposures started at 4 to 16 cell stage of the embryos and terminated 120 hours post fertilization (hpf). The expression of abcb4 gene in zebrafish embryos was examined on 48, 72, 96, and 120 hpf with whole-mount in situ hybridization (WISH) and quantitative real-time PCR (qPCR). RESULTS: Compared with the controls, DOX-exposed embryos had higher level of abcb4 gene expression (P < 0.05), but not for abcb5 gene. WISH showed that abcb4 gene was expressed in the guts of zebrafish embryos. However, those exposed to DOX also showed strong WISH signals in the brain and heart. CONCLUSION: Doxorubicin increases the expression of abcb4 gene in zebrafish embryos. abcb4 gene may play an imoortant role in multidrug-resistance.