CircSEC24A promotes tumor progression through sequestering miR-455-3p in hepatocellular carcinoma

The pivotal role of EMT-related noncoding RNAs regulatory axes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a major health problem worldwide, being the leading cause of cancer-related deaths, with limited treatment options, especially in its advanced stages. Tumor resistance is closely associated with the activation of the EMT phenomenon and its reversal, being modulated by different molecules, including noncoding RNAs (ncRNAs). Noncoding RNAs have the potential to function as both tumor suppressors and oncogenic molecules, controlling the malignant potential of HCC cells. Basically, these molecules circulate in the tumor microenvironment, encapsulated in exosomes. Their impact on cell biology is more significant than originally expected, which makes related research rather complex. The temporal and spatial expression patterns, precise roles and mechanisms of specific ncRNAs encapsulated in exosomes remain primarily unknown in different stages of the disease. This review aims to highlight the recent advances in ncRNAs related to EMT and classifies the described mechanism as direct and indirect, for a better summarization. Moreover, we provide an overview of current research on the role of ncRNAs in several drug resistance-related pathways, including the emergence of resistance to sorafenib, doxorubicin, cisplatin and paclitaxel therapy. Nevertheless, we comprehensively discuss the underlying regulatory mechanisms of exosomal ncRNAs in EMT-HCC via intercellular communication pathways.

MicroRNA-455-3p inhibits osteosarcoma progression via HSF1 downregulation

OBJECTIVE

This study was conducted to dissect the role and potential mechanism of microRNA (miR)-455-3p on osteosarcoma (OS) development.

METHODS

miR-455-3p and HSF1 expression in OS tissues were detected by RT-qPCR and western blot. Later, gain- and loss-of-function assays were implemented in OS cells U-2OS and MNNG. The expression of apoptosis-related genes was measured by RT-qPCR and western blot. MTT, Transwell, scratch test, and flow cytometry were utilized to test OS cell viability, invasion, migration, and apoptosis. The targeting relationship between miR-455-3p and HSF1 was assessed with a dual-luciferase reporter gene assay. The transplantation tumor experiment in nude mice was utilized for in vivo confirmation.

RESULTS

Downregulated miR-455-3p and upregulated HSF1 were displayed in OS tissues and cells. Mechanistically, miR-455-3p negatively targeted HSF1. MiR-455-3p inhibition or HSF1 overexpression increased MNNG and U-2OS cell proliferative, invasive, and migrating capabilities, while diminishing U-2OS cell apoptosis. Moreover, HSF1 overexpression negated the impacts of miR-455-3p upregulation on OS cell proliferative, invasive, migrating, and apoptotic abilities. Likewise, overexpressing miR-455-3p curtailed the growth of transplanted OS tumors through HSF1 repression.

CONCLUSION

MiR-455-3p inhibits the development of OS cells by downregulating HSF1, highlighting the possibility of miR-455-3p as an innovative indicator of prognosis and a therapeutic target for OS.

Hsa_circ_0003528 promotes cell malignant transformation and immune escape via increasing oncogene PDL1 through sponging miR-511-3p in non-small cell lung cancer

BACKGROUND

Accumulating evidence suggests that circular RNAs (circRNAs) play important regulatory roles in non-small cell lung cancer (NSCLC). At present, we aimed to explore the regulatory role of has_circ_0003528 (circ_0003528) in NSCLC.

METHODS

Alterations of circ_0003528 expression in NSCLC samples and cell lines were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Impacts of circ_0003528 on NSCLC cell malignant transformation were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell invasion, and tube formation assays. Epithelial-mesenchymal transition (EMT)-related markers were detected with western blotting. Pro-inflammatory cytokines were detected by Enzyme-linked immunosorbent assay (ELISA). The regulation mechanism of circ_0003528 was verified by dual-luciferase reporter and RNA pull-down assays. The tumorigenesis role of circ_0003528 was verified by animal experiments.

RESULTS

Higher levels of circ_0003528 were obtained in NSCLC samples and cell lines, and patients with high circ_0003528 expression had a worse prognosis. Silence of circ_0003528 decreased xenograft growth in mouse models and induced cell apoptosis and repressed cell viability, proliferation, invasion, EMT, angiogenesis, and immune escape in NSCLC cells in vitro. Mechanistically, circ_0003528 controlled programmed cell death ligand 1 (PDL1) expression through interaction with miR-511-3p. The inhibiting impacts of circ_0003528 knockdown on NSCLC cell malignant transformation and immune escape were weakened after miR-511-3p silencing. Moreover, PDL1 overexpression partially counteracted miR-511-3p upregulation-mediated suppression on NSCLC cell malignant transformation and immune escape.

CONCLUSIONS

Circ_0003528 facilitated NSCLC cell malignant transformation and immune escape through regulation of the miR-511-3p/PDL1 axis, highlighting the oncogenic role of circ_0003528 in NSCLC.

Silencing of lncRNA CRNDE attenuates nonsmall-cell lung cancer progression by mediating the miR-455-3p/HDAC2 axis

Nonsmall-cell lung carcinoma (NSCLC) is one of the deadliest malignancies in the world. LncRNAs are confirmed to be involved in the progression of NSCLC. Meanwhile, lncRNA CRNDE is known to be upregulated in NSCLC; however, the mechanism by which CRNDE regulates the tumourigenesis of NSCLC remains unclear. To test the function of CRNDE in NSCLC, cell proliferation, invasion, and migration were investigated by colony formation and Transwell assays, respectively. qPCR and Western blotting were applied to test gene and protein levels. In addition, the relationship among CRNDE, miR-455-3p, and HDAC2 was explored by dual-luciferase and RIP assays. The data revealed that the expression of CRNDE was upregulated in NSCLC tissues, while miR-455-3p was downregulated. CRNDE knockdown inhibited the viability, migration and invasion of NSCLC cells or epidermal growth factor receptor gene (EGFR)-mutant NSCLC cells. Moreover, inhibition of miR-455-3p exhibited the opposite effect. CRNDE bound with miR-455-3p, and HDAC2 was found to be targeted by miR-455-3p. Meanwhile, miR-455-3p downregulation reversed the effect of CRNDE knockdown on NSCLC cell function. Furthermore, miR-455-3p notably inhibited the growth and invasion of NSCLC cells via downregulation of HDAC2. Knockdown of CRNDE attenuated NSCLC progression via modulation of the miR-455-3p/HDAC2 axis. Thus, those findings might provide a novel strategy against NSCLC.