Long Noncoding RNA DICER1-AS1 Functions in Methylation Regulation on the Multi-Drugresistance of Osteosarcoma Cells via miR-34a-5p and GADD45A

MicroRNA-34 Family in Cancers: Role, Mechanism, and Therapeutic Potential

MicroRNA (miRNA) are small noncoding RNAs that play vital roles in post-transcriptional gene regulation by inhibiting mRNA translation or promoting mRNA degradation. The dysregulation of miRNA has been implicated in numerous human diseases, including cancers. miR-34 family members (miR-34s), including miR-34a, miR-34b, and miR-34c, have emerged as the most extensively studied tumor-suppressive miRNAs. In this comprehensive review, we aim to provide an overview of the major signaling pathways and gene networks regulated by miR-34s in various cancers and highlight the critical tumor suppressor role of miR-34s. Furthermore, we will discuss the potential of using miR-34 mimics as a novel therapeutic approach against cancer, while also addressing the challenges associated with their development and delivery. It is anticipated that gaining a deeper understanding of the functions and mechanisms of miR-34s in cancer will greatly contribute to the development of effective miR-34-based cancer therapeutics.

Hypermethylation-Mediated lncRNA MAGI2-AS3 Downregulation Facilitates Malignant Progression of Laryngeal Squamous Cell Carcinoma via Interacting With SPT6

Long noncoding RNAs (lncRNAs) have an effect on the occurrence and progression of a considerable number of diseases, especially cancer. Existing research has suggested that MAGI2 antisense RNA 3 (MAGI2-AS3) takes on a critical significance in the development of hepatocellular carcinoma and lung cancer. However, the functions of MAGI2-AS3 in laryngeal squamous cell carcinoma (LSCC) remain unclear. In this study, MAGI2-AS3 expression level in LSCC tissue and cell lines was detected, and the effect of MAGI2-AS3 overexpressed on LSCC phenotypes and the possible influence mechanisms were examined. MAGI2-AS3 was downregulated in the tissues of LSCC patients versus non-tumor tissues, and it was correlated with advanced TNM (tumor, node, metastasis) stage and lymph node metastases, as indicated by the results of this study. MAGI2-AS3 inhibited the proliferation, migration, and invasion of LSCC cells in vitro and in vivo. Furthermore, the hypermethylation level of the MAGI2-AS3 promoter region was indicated by bisulfite genomic sequencing and methylation-specific polymerase chain reaction, such that MAGI2-AS3 expression was downregulated. Besides, MAGI2-AS3 promoter hypermethylation was regulated by DNA methyltransferase 1 (DNMT1), and MAGI2-AS3 expression was reversed by 5-Aza-2'-deoxycytidine (5-Aza). Moreover, the result of the RNA pull-down experiment suggested that 38 proteins were enriched in the MAGI2-AS3 group versus the control group in TU177 cells. To be specific, SPT6 (ie, a conserved protein) was enriched by fold change >10. SPT6 knockdown reduced the antitumor effect of MAGI2-AS3 in TU177 and AMC-HN-8 cells. Meanwhile, SPT6 overexpression inhibited the proliferation, metastasis, and invasion of TU177 and AMC-HN-8 cells. As revealed by the above findings, DNMT1-regulated MAGI2-AS3 promoter hypermethylation led to downregulated MAGI2-AS3 expression, such that the presence and progression of LSCC were inhibited in an SPT6 binding-dependent manner.

LncRNA BACE1-AS promotes the progression of osteosarcoma through miR-762/SOX7 axis

BACKGROUND

Osteosarcoma (OS) is a rare malignant primary tumor of mesenchymal origin affecting bone that occurs in adolescents and children. LncRNAs are important regulators of tumorigenesis and development. This study aimed to explore the role and molecular basis of LncRNA BACE1-AS (BACE1 antisense RNA) in OS.

METHODS AND RESULTS

Through the analysis of differential expressed lncRNAs in OS tissues by GEO database, LncRNA BACE1-AS display a remarkably lower expression. This found can also be observed in both OS tissues and cell lines by qRT-PCR. Furthermore, using Cell counting kit-8 (CCK-8), transwell, wound healing and westernblot assays, overexpression LncRNA BACE1-AS remarkably reduce cell proliferation, migration and invasion abilities in OS. In addition, LncRNA BACE1-AS is validated as a sponge of miR-762 through the prediction of lncRNASNP. Further, luciferase reporter and RIP assays are conducted to confirm the binding sites between LncRNA BACE1-AS and miR-762. SRY-box transcription factor 7 (SOX7) target to miR-762 and regulated by LncRNA BACE1-AS. Moreover, inhibition of miR-762 attenuate the role of sh-LncRNA BACE1-AS in OS cells, at meanwhile reduce the expression of SOX7.

CONCLUSION

In this study, LncRNA BACE1-AS regulates proliferation, migration and invasion of osteosarcoma cells by miR-762/SOX7 axis, implying that LncRNA BACE1-AS is a potential target for osteosarcoma therapy.

Maackiain Modulates miR-374a/GADD45A Axis to Inhibit Triple-Negative Breast Cancer Initiation and Progression

Breast cancer ranks as the leading cause of death in lethal malignancies among women worldwide, with a sharp increase of incidence since 2008. Triple negative breast cancer (TNBC) gives rise to the largest proportion in breast cancer-related deaths because of its aggressive growth and rapid metastasis. Hence, searching for promising targets and innovative approaches is indispensable for the TNBC treatment. Maackiain (MA), a natural compound with multiple biological activities, could be isolated from different Chinese herbs, such as Spatholobus suberectus and Sophora flavescens. It was the first time to report the anti-cancer effect of MA in TNBC. MA could suppress TNBC cell proliferation, foci formation, migration, and invasion. MA also exerted a significant inhibitory effect on tumor growth of TNBC. Furthermore, MA could induce apoptosis with an increase of GADD45α and a decrease of miR-374a. In contrast, overexpressing miR-374a would result in at least partly affecting the proapoptotic effect of MA and suppressing GADD45α stimulated by MA. These results reveal the anti-TNBC effect of MA in vitro and in vivo, providing evidence for its potential as a drug candidate utilized in TNBC therapy.