MicroRNA-889-3p restrains the proliferation and epithelial-mesenchymal transformation of lung cancer cells via down-regulation of Homeodomain-interacting protein kinase 1

Circ_0002669 promotes osteosarcoma tumorigenesis through directly binding to MYCBP and sponging miR-889-3p

Circular RNAs (circRNAs) are a class of highly multifunctional single-stranded RNAs that play crucial roles in cancer progression, including osteosarcoma (OS). Circ_0002669, generated from the dedicator of cytokinesis (DOCK) gene, was highly expressed in OS tissues, and negatively correlated with OS patient survival. Elevated circ_0002669 promoted OS cell growth and invasion in vivo and in vitro. By biotin pulldown and mass spectroscopy, we found that circ_0002669 directly bound to MYCBP, a positive regulator of c-myc, to prevent MYCBP from ubiquitin-mediated proteasome degradation. In addition, circ_0002669 interacted with miR-889-3p and served as a miRNA sponge to increase the expression of MYCBP, as determined by luciferase assays and RNA immunoprecipitation. Functional rescue experiments indicated MYCBP acted as a key factor for circ_0002669- and miR-889-3p-regulated OS cell proliferation and migration. Increased expression of c-myc-associated genes, such as CCND1, c-Jun and CDK4, were found in circ_0002669- and MYCBP-overexpressing OS cells. Our data thus provide evidence that circ_0002669 promotes OS malignancy by protecting MYCBP from protein ubiquitination and degradation and blocking miR-889-3p-mediated inhibition of MYCBP expression.

miR-889-3p Facilitates the Browning Process of White Adipocyte Precursors by Targeting the SON Gene

It is well-established that beige/brown adipose tissue can dissipate stored energy through thermogenesis; hence, the browning of white adipocytes (WAT) has garnered significant interest in contemporary research. Our preceding investigations have identified a marked downregulation of miR-889-3p concurrent with the natural maturation of brown adipose tissue. However, the specific role and underlying molecular mechanisms of miR-889-3p in the browning process of white adipose tissue warrant further elucidation. In this research, we initially delved into the potential role of miR-889-3p in preadipocyte growth via flow cytometry and CCK-8 assay, revealing that miR-889-3p can stimulate preadipocyte growth. To validate the potential contribution of miR-889-3p in the browning process of white adipose tissue, we established an in vitro rabbit white adipocyte browning induction, which exhibited a significant upregulation of miR-889-3p during the browning process. RT-qPCR and Western blot analysis indicated that miR-889-3p overexpression significantly amplified the mRNA levels of UCP1, PRDM16, and CIDEA, as well as UCP1 protein levels. Furthermore, miR-889-3p overexpression fostered intracellular triglyceride accumulation. Conversely, the downregulation of miR-889-3p hindered the browning of rabbit preadipocytes. Subsequently, based on target gene prediction and luciferase reporter gene determination, we demonstrated that miR-889-3p directly targets the 3'-UTR region of SON. Lastly, we observed that inhibiting SON could facilitate the browning of rabbit preadipocytes. In conclusion, our findings suggest that miR-889-3p facilitates the browning process of white adipocyte precursors by specifically targeting the SON gene.

miRNAs and exosomal miRNAs in lung cancer: New emerging players in tumor progression and therapy response

Non-coding RNAs have shown key roles in cancer and among them, short RNA molecules are known as microRNAs (miRNAs). These molecules have length less than 25 nucleotides and suppress translation and expression. The functional miRNAs are produced in cytoplasm. Lung cancer is a devastating disease that its mortality and morbidity have undergone an increase in recent years. Aggressive behavior leads to undesirable prognosis and tumors demonstrate abnormal proliferation and invasion. In the present review, miRNA functions in lung cancer is described. miRNAs reduce/increase proliferation and metastasis. They modulate cell death and proliferation. Overexpression of oncogenic miRNAs facilitates drug resistance and radio-resistance in lung cancer. Tumor microenvironment components including macrophages and cancer-associated fibroblasts demonstrate interactions with miRNAs in lung cancer. Other factors such as HIF-1α, lncRNAs and circRNAs modulate miRNA expression. miRNAs have also value in the diagnosis of lung cancer. Understanding such interactions can pave the way for developing novel therapeutics in near future for lung cancer patients.

Long non-coding RNA GNAS-AS1 knockdown inhibits proliferation and epithelial-mesenchymal transition of lung adenocarcinoma cells via the microRNA-433-3p/Rab3A axis

The goal of this study was to demonstrate the functions and specific mechanism of long non-coding RNA (lncRNA) GNAS-AS1 in lung adenocarcinoma. Levels of lncRNA GNAS-AS1, microRNA (miR)-433-3p, and Rab3A were assessed by quantitative real-time PCR (qRT-PCR). The target-binding sites of lncRNA GNAS-AS1, miR-433-3p, and Rab3A were predicted and confirmed by bioinformatics tool (StarBase) and a dual-luciferase reporter system. Cell proliferation and apoptosis were checked using MTT and flow cytometry, respectively. Additionally, the levels of apoptosis-related and epithelial-mesenchymal transition (EMT)-associated genes in A549 cells were analyzed by qRT-PCR and western blot. We found that lncRNA GNAS-AS1 was upregulated, miR-433-3p was low-expressed, and Rab3A was overexpressed in lung adenocarcinoma tissues and cell lines. LncRNA GNAS-AS1 interacted with miR-433-3p and negatively regulated miR-433-3p levels. Rab3A was a direct target of miR-433-3p. Downregulation of lncRNA GNAS-AS1 remarkably suppressed cell proliferation, promoted cell apoptosis, decreased B-cell lymphoma-2 (Bcl-2) expression, enhanced the Bcl-2-Associated X (Bax) level, promoted E-cadherin expression, and reduced N-cadherin and Rab3A levels. However, the miR-433-3p inhibitor reversed all these findings. Similarly, the inhibitory effects of miR-433-3p mimic on A549 cells were reversed by the Rab3A-plasmid. In conclusion, lncRNA GNAS-AS1 downregulation suppressed lung adenocarcinoma cell proliferation and EMT through the miR-433-3p/Rab3A axis.

Interplay between programmed death-ligand 1 and non-coding RNAs

Programmed death-ligand 1 (PD-L1) is a transmembrane protein with essential roles in the suppression of adaptive immune responses. As an immune checkpoint molecule, PD-L1 can be exploited by cancer cells to evade the anti-tumor attacks initiated by the immune system. Thus, blockade of the PD1/PD-L1 axis can eliminate the suppressive signals and release the antitumor immune responses. Identification of the underlying mechanisms of modulation of the activity of the PD1/PD-L1 axis would facilitate the design of more efficacious therapeutic options and better assignment of patients for each option. Recent studies have confirmed the interactions between miRNAs/lncRNAs/circ-RNAs and the PD1/PD-L1 axis. In the current review, we give a summary of interactions between these transcripts and PD-L1 in the context of cancer. We also overview the consequences of these interactions in the determination of the response of patients to anti-cancer drugs.

Circular RNA_0120376 regulates microRNA-148b-3 and centrosomal protein 55 to promote non-small cell lung cancer development

Circular RNAs (circRNAs) are non-coding RNAs with covalent closed-loop structures that are vital in regulating diverse pathological processes. This work is aimed to investigate the role of circ_0120376 in non-small cell lung cancer (NSCLC). Circ_0120376, microRNA (miR)-148b-3p, and centrosomal protein 55 (CEP55) mRNA expression in NSCLC tissues and cells were determined using qRT-PCR. The influences of circ_0120376 and miR-148b-3p on the proliferation of NSCLC cell lines were analyzed by CCK-8 and colony formation assays. Apoptosis was analyzed by flow cytometry. Cell migration and invasion were analyzed using the Transwell experiment. Binding relationships between circ_0120376 and miR-148b-3p and between miR-148b-3p and CEP55 3'UTR were investigated using the dual-luciferase reporter experiment and the RIP experiment. Western blot was conducted to analyze the regulatory effect of circ_0120376 and miR-148b-3p on CEP55 expression. We found that circ_0120376 was markedly overexpressed in NSCLC, and its overexpression was positively associated with increased T stage and lymph node metastasis of the patients. Functional experiments unveiled that circ_0120376 enhanced the proliferation, migration and invasion of NSCLC cells and impeded apoptosis, while knocking down circ_0120376 remarkably suppressed the malignant features of NSCLC cells mentioned above. Circ_0120376 could adsorb miR-148b-3p to reduce miR-148b-3p expression, and circ_0120376 could increase CEP55 expression via adsorbing miR-148b-3p. In summary, circ_0120376 contributes to the malignancy of NSCLC cells through a ceRNA mechanism via regulating miR-148b-3p/CEP55 axis. Circ_0120376 is likely to be a potential diagnostic biomarker and therapeutic target for NSCLC.

Long non-coding RNA HOXA11 antisense RNA upregulates spermatogenesis-associated serine-rich 2-like to enhance cisplatin resistance in laryngeal squamous cell carcinoma by suppressing microRNA-518a

Long noncoding RNAs (LncRNAs) are closely associated with the chemoresistance of laryngeal squamous cell carcinoma (LSCC). Previous studies indicated that HOXA11-AS could function as a vital regulator in human cancers. However, the regulatory mechanisms of HOXA11-AS in the chemoresistance of LSCC remain unclear. In this study, it was found that HOXA11-AS expression was upregulated in cisplatin (CDDP)-resistant LSCC tissues and cells. Loss-of-function assays revealed that HOXA11-AS knockdown inhibited the viability, migration, and invasion, but promoted the apoptosis of CDDP-resistant LSCC cells. Meanwhile, we identified miR-518a as a downstream gene of HOXA11-AS in LSCC, and miR-518a silencing reversed the promotive effect of HOXA11-AS knockdown on CDDP sensitivity of LSCC cells. In addition, miR-518a could inhibit spermatogenesis-associated serine-rich 2-like (SPATS2L) expression by direct interaction, and upregulation of SPATS2L abrogated the inhibitory effect of HOXA11-AS silencing or miR-518a overexpression on CDDP resistance of CDDP-resistant LSCC cells. In sum, our results demonstrated that HOXA11-AS enhanced CDDP resistance of LSCC via miR-518a/SPATS2L axis, which might offer novel therapeutic strategies for CDDP-resistant LSCC.

Inhibition of integrin subunit alpha 11 restrains gastric cancer progression through phosphatidylinositol 3-kinase/Akt pathway

Gastric cancer (GC) is among the most frequent malignancies originating from the digestive system worldwide, while the role and specific mechanism of integrin-subunit alpha 11 (ITGA11) in GC remain unclear. This study probes the expression characteristics and function of ITGA11 in GC. Firstly, the ITGA11 profile in GC tissues and paracancerous non-tumor tissues was assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot (WB), and the association between ITGA11 and GC patients' clinicopathological indicators was evaluated. ITGA11 knockdown models were set up in GC cell lines MKN45 and AGS. Cell proliferation was determined by the cell counting kit-8 (CCK-8) assay and colony formation assay. WB was utilized to gauge the expression of apoptosis-related proteins (Bax, Bcl2, Bad, and C-Caspase3) and the PI3K/AKT pathway. We discovered that the ITGA11 expression was boosted in GC tissues and was related to the unfavorable prognosis of GC patients. Additionally, ITGA11 knockdown abated GC cell proliferation, invasion and migration, and enhanced cell apoptosis. In animal experiments, the tumorigenesis of GC cells knocking down ITGA11 was reduced. Mechanically, knocking down ITGA11 notably inactivated the PI3K/AKT axis. The tumor-suppressive effect mediated by ITGA11 knockdown was attenuated after activating the PI3K/AKT pathway with insulin-like growth factor 1 (IGF-1). Overall, this study substantiated that the ITGA11 expression was heightened in GC tissues, which affected GC progression by modulating the PI3K/AKT pathway.