TCM therapies combined with chemotherapy for preventing recurrence and metastasis in postoperative II to IIIA NSCLC: A protocol for a systematic review and meta-analysis

circ_0006528 promotes nonsmall cell lung cancer progression by sponging miR-892a and regulating NRAS expression

Micro-RNAs play essential roles in developing and progressing nonsmall cell lung cancer (NSCLC) and drug resistance. Nevertheless, the functions and mechanisms are partly explored. Therefore, the present study analyzes the effect of circ_0006528 and the mechanism of regulation of NSCLC cell progression by sponging miR-892a to regulate neuroblastoma rat sarcoma viral oncogene (NRAS) expression. Initially, circ_0006528 is identified using divergent primers-based PCR and RNase R exonuclease treatments. After administration of the designed circ_0006528-specific siRNA, the RT-qPCR analysis is used to determine the interference efficiency of siRNA. At the same time, cell growth, invasion, and migration are assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT), Transwell, and scratch assays in the NSCLC cell lines (secretory pathway Ca2+-ATPase isoform 1 [SPCA-1] and A549) in vitro, respectively. Further, miR-892a inhibitor is added to the cells for functional recovery assay. Finally, the xenograft mouse model is constructed to explore the effect of circ_0006528 on tumor growth in vivo. The RT-qPCR analysis in 66 pairs of NSCLC cancer and noncancerous tissues revealed that circ_0006528 is highly expressed in NSCLC patient tissues. The RNase R experiments revealed that HSA_circ_0006528 is unaffected by RNase R exonuclease. MTT assay showed that knockdown of hsa_circ_0006528 by siRNA significantly decreased cell proliferation and viability in A549 and SPCA-1 cells. The luciferase reporter assay showed direct binding of hsa_circ_0006528 to miR-892a, and miR-892a targets binding NRAS. In addition, the miR-892a inhibitor terminated the hsa_circ_0006528 siRNA, triggering inhibition of proliferation, invasion, and migration of NSCLC cells. In summary, the study revealed that the knockout of hsa_circ_0006528 downregulation of NRAS expression by sponging miR-892a inhibited NSCLC cell growth and invasion.

METTL3 Mediated MALAT1 m6A Modification Promotes Proliferation and Metastasis in Osteosarcoma Cells

BACKGROUND

As one of the most ubiquitous types of posttranscriptional modification, N6-methyladenosine (m6A) is extensively implicated in almost all types of cancers, including osteosarcoma. Our previous research partially uncovered the role of Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) in osteosarcoma. However, the relationships between methyltransferase-like 3 (METTL3) and noncoding RNAs modified by METTL3, especially MALAT1, in osteosarcoma remain obscure.

METHODS

The expression of METTL3 in osteosarcoma was evaluated by online bioinformatics analysis, immunohistochemical (IHC) staining, western blotting (WB), and reverse transcription-quantitative PCR (RT‒qPCR). Cell Counting Kit 8 (CCK-8) and Transwell assays were used to evaluate the cell proliferation and invasion abilities. The expression of MALAT1 in osteosarcoma was evaluated by online bioinformatics analysis and RT‒qPCR analysis. m6A methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) was used to detect m6A modification changes in MALAT1. An actinomycin D assay was used to study changes in the stability of MALAT1.

RESULTS

METTL3 was upregulated in osteosarcoma tissues and cell lines. Functionally, METTL3 promoted the proliferation and migration of osteosarcoma cells. Moreover, a clear positive correlation was found between METTL3 and MALAT1 expression, and MALAT1 was upregulated in osteosarcoma tissues and cells. Mechanistically, the presence of m6A modification sites in MALAT1 and METTL3-mediated m6A modification increased the stability of MALAT1 in osteosarcoma cells and promoted their proliferation and migration.

CONCLUSION

In this study, it was concluded that in osteosarcoma cells, METTL3, acting as an oncogene, promoted m6A modification of MALAT1, increased the stability of MALAT, and enhanced MALAT1-mediated oncogenic function.

CirRNA circFAM126A Exerts Oncogenic Functions in NSCLC to Upregulate IRS2

Non-small cell lung cancer (NSCLC) is a common histological subtype of lung cancer, which occupies 80-85% of the proportion in all lung cancer cases. Therefore, this study was designed to clarify the role and underlying molecular mechanisms of circFAM126A in NSCLC. The real-time quantitative polymerase chain reaction (RT-qPCR) assay was conducted to assess circFAM126A, FAM126A, miR-613, and IRS2 expression in NSCLC tissues and cells. The proliferation ability of cells was measured by MTT, EdU, and colony-forming assays. The flow cytometry assay was performed to evaluate cell cycle distribution and apoptosis of NSCLC cells. The migration and invasion were determined by wound healing and transwell matrigel assays, respectively. The interaction relationship between miR-613 and circFAM126A or IRS2 was analyzed by dual-luciferase reporter and RNA pull-down assays. Tumorigenesis in nude mice was conducted to clarify the functional roles of circFAM126A inhibition in vivo. CircFAM126A was obviously overexpressed in NSCLC tissues and cells when compared with controls. The loss-of-functional experiments suggested that knockdown of circFAM126A suppressed proliferation, migration and invasion, as well as caused apoptosis and cell cycle arrest in NSCLC cells, which was abolished by silencing of miR-613. In addition, IRS2 was a target gene of miR-613. Overexpression of miR-613 exerted carcinoma inhibitor role in NSCLC by inhibition of IRS2 expression. Consistently, the silencing of circFAM126A also functioned anti-tumorigenic roles in nude mice in vivo. Mechanistically, circFAM126A could function as a miRNA sponge for miR-613 to regulate the expression of IRS2, thereby regulating proliferation, migration, invasion, apoptosis, and cell cycle arrest in NSCLC cells.

Long Non-Coding RNA CAR10 Facilitates Non-Small Cell Lung Cancer Cell Migration and Invasion by Modulating the miR-892a/GJB2 Pathway

Introduction

Non-coding RNAs, including long non-coding (lnc)RNAs and microRNAs (miRs), play crucial roles in numerous malignant tumors, including non-small cell lung cancer (NSCLC).

Methods

The expression levels of chromatin-associated RNA Intergenic 10 (CAR10), gap junction protein beta 2 (GJB2) and miR-892a in NSCLC were evaluated by reanalyzing three Gene Expression Omnibus (GEO) datasets, and performing reverse transcription-quantitative PCR, immunohistochemistry staining and Western blot analysis, accordingly. Functionally, Transwell and Matrigel assays were performed to measure changes in the migration and invasion abilities of the A549 and H1299 cell lines. The targeted binding effects between CAR10 and miR-892a, as well as between miR-892a and GJB2 were confirmed by conducting dual-luciferase reporter and RNA pull-down assays, respectively.

Results

The present study demonstrated that CAR10 was upregulated in patients with NSCLC, which was also associated with a poor prognosis. Functionally, CAR10 was confirmed to be oncogenic and promoted NSCLC cell migration and invasion, using overexpression and knockdown Transwell assays. Furthermore, GJB2 expression was revealed to be upregulated and was positively correlated with CAR10 expression in NSCLC. A further mechanistic study revealed that GJB2 was a downstream target of CAR10, which induced the migration and invasive potential of the A549 and H1299 cell lines. More specifically, miR-892a was found to serve as a bridge between CAR10 and GJB2, via similar miRNA response elements. The RNA pull-down and luciferase assays indicated that miR-892a directly binds both CAR10 and GJB2.

Conclusion

CAR10 promoted NSCLC cell migration and invasion by upregulating GJB2 and sponging miR-892a. These findings illustrated that the CAR10/miR-892a/GJB2 axis may be a novel molecular target for the treatment of NSCLC.