Does Smad6 methylation control BMP signaling in cancer?

Honokiol inhibits human osteosarcoma MG63 cell migration by upregulating FTO and Smad6 to promote autophagy

BACKGROUND

Osteosarcoma (OS) is a common primary malignant tumor of bone, most commonly seen in children and adolescents, which has a low survival rate and is a serious threat to patients' lives. Honokiol (HKL) is the main active components of Magnolia officinalis, which have significant anti-tumor properties. The aim of this study was to observe the autophagic and migratory effects of HKL on MG63 cells and to investigate whether the mechanism of action was related to FTO and Smad6.

METHODS

Firstly, we cultured MG63 cells in vitro and intervened with different concentrations of HKL to detect cell activity by CCK8, apoptosis by flow cytometry, cell migration ability by scratch assay, cell invasion ability by transwell assay and MMP2, P62, LC3 I/II, FTO and Smad6 protein expression by Western blot.

RESULTS

HKL inhibited MG63 cells activity and that this effect was dose and time dependent. Although there was no significant effect on apoptosis and invasive ability, HKL could act through effects such as promoting cell autophagy and inhibiting migration. HKL increased the protein expression levels of FTO, Smad6, MMP2, LC3 I/II and P62, and this effect was reduced after silencing of Smad6.

CONCLUSIONS

HKL induced autophagy and inhibited cell migration in MG63 cells by increasing the expression of FTP and Smad6. It can be seen that HKL may be a promising drug for the treatment of OS.

The Role of miRNAs, circRNAs and Their Interactions in Development and Progression of Hepatocellular Carcinoma: An Insilico Approach

Hepatocellular carcinoma (HCC) is a type of malignant tumor. miRNAs are noncoding RNAs and their differential expression patterns are observed in HCC-induced by alcoholism, HBV and HCV infections. By acting as a competing endogenous RNA (ceRNA), circRNA regulates the miRNA function, indirectly controlling the gene expression and leading to HCC progression. In the present study, data mining was performed to screen out all miRNAs and circRNA involved in alcohol, HBV or HCV-induced HCC with statistically significant (≤0.05%) expression levels reported in various studies. Further, the interaction of miRNAs and circRNA was also investigated to explore their role in HCC due to various causative agents. Together, these study data provide a deeper understanding of the circRNA-miRNA regulatory mechanisms in HCC. These screened circRNA, miRNA and their interactions can be used as prognostic biomarkers or therapeutic targets for the treatment of HCC.

Circular RNA hsa_circ_0000517 modulates hepatocellular carcinoma advancement via the miR-326/SMAD6 axis

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common malignant heterogeneous disease in primary liver tumors. Circular RNA hsa_circ_0000517 (hsa_circ_0000517) is connected with HCC prognosis. Nevertheless, there are few studies on the role and mechanism of hsa_circ_0000517 in HCC.

METHODS

Expression of hsa_circ_0000517, miR-326, and SMAD family member 6 (SMAD6) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, colony formation, cell cycle, migration, and invasion were determined though Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, wound healing, or transwell assays. Protein levels of Cyclin D1, matrix metalloproteinase-2 (MMP2), matrix metalloproteinase-9 (MMP9), SMAD6, and proliferating cell nuclear antigen (PCNA) were examined with western blot analysis. The relationship between hsa_circ_0000517 or SMAD6 and miR-326 was determined via dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The role of hsa_circ_0000517 in vivo was confirmed via xenograft assay.

RESULTS

Hsa_circ_0000517 and SMAD6 were up-regulated while miR-326 was down-regulated in HCC tissues and cells. Hsa_circ_0000517 down-regulation repressed cell proliferation, colony formation, migration, and invasion, and induced cell cycle arrest in HCC cells in vitro, and constrained tumor growth in vivo. Notably, hsa_circ_0000517 regulated SMAD6 expression via acting as a competing endogenous RNA (ceRNA) for miR-326. And the repressive influence on malignant behaviors of HCC cells mediated by hsa_circ_0000517 inhibition was reversed by miR-326 inhibitors. Moreover, SMAD6 elevation overturned the inhibitory impacts of miR-326 mimics on malignant behaviors of HCC cells.

CONCLUSIONS

Hsa_circ_0000517 depletion repressed HCC advancement via regulating the miR-326/SMAD6 axis.

Non-histone protein methylation as a regulator of cellular signalling and function

Methylation of Lys and Arg residues on non-histone proteins has emerged as a prevalent post-translational modification and as an important regulator of cellular signal transduction mediated by the MAPK, WNT, BMP, Hippo and JAK-STAT signalling pathways. Crosstalk between methylation and other types of post-translational modifications, and between histone and non-histone protein methylation frequently occurs and affects cellular functions such as chromatin remodelling, gene transcription, protein synthesis, signal transduction and DNA repair. With recent advances in proteomic techniques, in particular mass spectrometry, the stage is now set to decode the methylproteome and define its functions in health and disease.