METTL3 Promotes Osteosarcoma Metastasis via an m6A-dependent Epigenetic Activity of CBX4.

BACKGROUND: Osteosarcoma cells are prone to metastasis, and the mechanism of N6-methyladenosine (m6A) methylation modification in this process is still unclear. Methylation modification of m6A plays an important role in the development of osteosarcoma, which is mainly due to abnormal expression of enzymes related to methylation modification of m6A, which in turn leads to changes in the methylation level of downstream target genes messenger RNA (mRNA) leading to tumor development. METHODS: We analyzed the expression levels of m6A methylation modification-related enzyme genes in GSE12865 whole-genome sequencing data. And we used shRNA (short hairpin RNA) lentiviral interference to interfere with METTL3 (Methyltransferase 3) expression in osteosarcoma cells. We studied the cytological function of METTL3 by Cell Counting Kit-8 (CCK8), flow cytometry, migration and other experiments, and the molecular mechanism of METTL3 by RIP (RNA binding protein immunoprecipitation), Western blot and other experiments. RESULTS: We found that METTL3 is abnormally highly expressed in osteosarcoma and interferes with METTL3 expression in osteosarcoma cells to inhibit metastasis, proliferation, and apoptosis of osteosarcoma cells. We subsequently found that METTL3 binds to the mRNA of CBX4 (chromobox homolog 4), a very important regulatory protein in osteosarcoma metastasis, and METTL3 regulates the mRNA and protein expression of CBX4. Further studies revealed that METTL3 inhibited metastasis of osteosarcoma cells by regulating CBX4. METTL3 has been found to be involved in osteosarcoma cells metastasis by CBX4 affecting the protein expression of matrix metalloproteinase 2 (MMP2), MMP9, E-Cadherin and N-Cadherin associated with osteosarcoma cells metastasis. CONCLUSIONS: These results suggest that the combined action of METTL3 and CBX4 plays an important role in the regulation of metastasis of osteosarcoma, and therefore, the METTL3-CBX4 axis pathway may be a new potential therapeutic target for osteosarcoma.

Ellagic acid induces apoptosis and autophagy in colon cancer through the AMPK/mTOR pathway.

Ellagic acid (EA), found in fruits and foods, has been shown to be effective in the treatment of breast, colon and bladder cancer. However, due to the complexity of colon cancer, the therapeutic mechanism of EA for colon cancer is still unclear. Cell Counting Kit-8 (CCK-8) assay were employed to investigate the cell proliferation. Western blotting and flow cytometry assays were utilized to investigate apoptosis and autophagy in CRC cells (HCT116), respectively. Moreover, western blotting and luciferase reporter assays were evaluated the effect of EA on AMPK/mTOR pathway. Through flow cytometry analysis, EA could promote the apoptosis of HCT116 cells. In addition, EA can reduce the phosphorylation of mTOR, promoted phosphorylation of AMPK, and induced autophagy in HCT116 cells. Also, Dorsomorphin pretreatment can reduce the expression of autophagy protein, which indicates that EA induces autophagy through AMPK/mTOR pathway. These results suggest that EA inhibits the growth of colon cancer through AMPK/mTOR pathway and induces apoptosis and protective autophagy.

Peramivir, an Anti-Influenza Virus Drug, Exhibits Potential Anti-Cytokine Storm Effects.

Coronavirus Disease 2019 (COVID-19) infected by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has been declared a public health emergency of international concerns. Cytokine storm syndrome (CSS) is a critical clinical symptom of severe COVID-19 patients, and the macrophage is recognized as the direct host cell of SARS-CoV-2 and potential drivers of CSS. In the present study, peramivir was identified to reduce TNF-α by partly intervention of NF-κB activity in LPS-induced macrophage model. In vivo, peramivir reduced the multi-cytokines in serum and bronchoalveolar lavage fluid (BALF), alleviated the acute lung injury and prolonged the survival time in mice. In human peripheral blood mononuclear cells (hPBMCs), peramivir could also inhibit the release of TNF-α. Collectively, we proposed that peramivir might be a candidate for the treatment of COVID-19 and other infections related CSS.

Drug repurposing of anti-infective clinical drugs: Discovery of two potential anti-cytokine storm agents.

Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2) has been widely spread in the world with a high mortality. Cytokine storm syndrome (CSS) and acute lung injury caused by SARS-CoV-2 infection severely threaten the patients. With the purpose to find effective and low-toxic drugs to mitigate CSS, entecavir and imipenem were identified to reduce TNF-α using a LPS-induced macrophage model from the anti-infective drug library. Entecavir and imipenem efficiently suppressed the release of inflammatory cytokines by partly intervention of NF-κB activity. The acute lung injury was also alleviated and the survival time was prolonged in mice. In addition, entecavir and imipenem inhibited the release of TNF-α and IL-10 in human peripheral blood mononuclear cells (hPBMCs). Collectively, we proposed that entecavir and imipenem might be candidates for the treatment of CSS.

Diallyl Trisulfide can induce fibroblast-like synovial apoptosis and has a therapeutic effect on collagen-induced arthritis in mice via blocking NF-κB and Wnt pathways.

BACKGROUND: Diallyl Trisulfide (DATS) is an organosulfur compound extracted from garlic bulb, and exerts cardioprotective, anti-inflammatory, antioxidant, antimicrobial and anticancer effects. But its role in the pathogenesis of rheumatoid arthritis (RA) is unknown. Here we explored the influence of DATS on human fibroblast-like synoviocytes (FLS) isolated from RA patients and a mouse model of collagen-induced arthritis (CIA) and the underlying mechanism. METHODS: RA-FLS were cultured and treated with different concentrations of DATS. The CCK8 assay was used to assess cell proliferation while cell apoptosis was detected by flow cytometry and western blot. The IL-8, IL-6 and IL-1ß levels were determined using RT-qPCR and ELISA assay. The expression of proteins of the NF-κB and Wnt pathways were measured using western blot. Furthermore, the effect of DATS was also explored in vivo using the collagen-induced arthritis mouse model. The Th17/Treg pattern obtain from cells of spleen of collagen-induced arthritis mouse model was detected by flow cytometry. RESULTS: Our results showed that DATS could decrease cell viability and introduce apoptosis in RA-FLS. Furthermore, DATS significantly attenuated the production of key inflammatory cytokines induced by RA-FLS cells following treatment with tumor necrosis α (TNF-α) at a concentration of 100 µM or higher. This was due to its inhibitory effect on the NF-κB and Wnt pathway signaling in RA-FLS. Additionally, DATS decreased the production of inflammatory cytokines and regulated the immune function by restoring the balance between Th17 and Treg in CIA mouse model. CONCLUSIONS: In conclusion, DATS may serve as a potential curative agent for RA.

Potentials of the elevated circulating miR-185 level as a biomarker for early diagnosis of HBV-related liver fibrosis.

Early diagnosis of liver fibrosis is critical for early intervention and prognosis of various chronic liver diseases. Conventional repeated histological assessment is impractical due to the associated invasiveness. In the current study, we evaluated circulating miR-185 as a potential biomarker to predict initiation and progression of liver fibrosis. We found that miR-185 was significantly up-regulated in blood specimens from patients with HBV-liver fibrosis and rats with liver fibrosis, the miR-185 levels were correlated with liver fibrosis progression, but not with the different viral loads in HBV-infected patients. miR-185 was observed in collagen deposition regions during advanced liver fibrosis. We found that differences in miR-185 levels facilitated the discrimination between early-staged or advanced-staged liver fibrosis and the healthy controls with high specificity, sensitivity, and likelihood ratio using receiver-operator characteristic analysis. miR-185 targeted SREBF1, and increased expression of COL1A1 and a-SMA genes that are hallmarks of liver fibrosis. Our data supported that circulating miR-185 levels could be used as potential biomarkers for the early diagnosis of liver fibrosis.