LINC01089 functions as a ceRNA for miR-152-3p to inhibit non-small lung cancer progression through regulating PTEN

FAK-LINC01089 negative regulatory loop controls chemoresistance and progression of small cell lung cancer

The focal adhesion kinase (FAK) tyrosine kinase is activated and upregulated in multiple cancer types including small cell lung cancer (SCLC). However, FAK inhibitors have shown limited efficacy in clinical trials for cancer treatment. With the aim of identifying potential therapeutic strategies to inhibit FAK for cancer treatment, we investigated long non-coding RNAs (lncRNAs) that potentially regulate FAK in SCLC. In this study, we identified a long non-coding RNA LINC01089 that binds and inhibits FAK phosphorylation (activation). Expression analysis revealed that LINC01089 was downregulated in SCLC tissues and negatively correlated with chemoresistance and survival in SCLC patients. Functionally, LINC01089 inhibited chemoresistance and progression of SCLC in vitro and in vivo. Mechanistically, LINC01089 inhibits FAK activation by blocking binding with Src and talin kinases, while FAK negatively regulates LINC01089 transcription by activating the ERK signaling pathway to recruit the REST transcription factor. Furthermore, LINC01089-FAK axis mediates the expression of drug resist-related genes by modulating YBX1 phosphorylation, leading to drug resistance in SCLC. Intriguingly, the FAK-LINC01089 interaction depends on the co-occurrence of the novel FAK variant and the non-conserved region of LINC01089 in primates. In Conclusion, our results indicated that LINC01089 may serve as a novel high-efficiency FAK inhibitor and the FAK-LINC01089 axis represents a valuable prognostic biomarker and potential therapeutic target in SCLC.

Long intergenic non-protein-coding RNA 1547 acts as a competing endogenous RNA and exerts cancer-promoting activity in non-small cell lung cancer by targeting the microRNA-195-5p/ homeobox C8 axis

Long intergenic non-protein coding RNA 1547 (LINC01547) presents a notable relationship with prognosis in patients with ovarian cancer. Herein, we examined the expression of LINC01547 in non-small cell lung cancer (NSCLC) to ascertain its clinical significance. We also explored the detailed functions of LINC01547 in regulating the aggressive phenotype of NSCLC and the molecular mechanism of action underlying its carcinogenic activities events in NSCLC. Furthermore, we applied the data acquired from the tissue specimens and the Cancer Genome Atlas (TCGA) database to analyze the level of LINC01547 in NSCLC and conducted functional assays to address the regulatory effect of LINC01547. Further, we examined the mechanistic interaction among LINC01547, microRNA-195-5p (miR-195-5p), and homeobox C8 (HOXC8) using bioinformatics prediction and luciferase reporter assay. LINC01547 was noticeably overexpressed, as affirmed by data from TCGA and our own cohort; moreover, poor prognosis was associated with increased LINC01547 levels in patients with NSCLC. LINC01547 regulates cell proliferation, colony-forming, migration, and invasion, and its absence produced tumor-repressing effects in NSCLC. Mechanistically, as a competitive endogenous RNA, LINC01547 decoyed miR-195-5p and consequently resulted in the overexpression of HOXC8 in NSCLC cells. Using rescue experiments, we found that the regulatory activities of LINC01547 deficient in repressing the malignant properties of NSCLC cells could be counteracted by hindering miR-195-5p or overexpressing HOXC8. Conclusively, LINC01547 serves as a crucial component to worsen the oncogenicity of NSCLC cells by controlling the miR-195-5p/HOXC8 axis. Thus, the newly identified competing endogenous RNA pathway may potentially be an attractive therapeutic for NSCLC management.

ELF1 suppresses autophagy to reduce cisplatin resistance via the miR-152-3p/NCAM1/ERK axis in lung cancer cells

Resistance to chemotherapeutic drugs limits the efficacy of chemotherapy in non-small cell lung cancer (NSCLC). Autophagy is an essential mechanism which involves in drug resistance. Our previous research has revealed that miR-152-3p represses NSCLC progression. However, the mechanism of miR-152-3p in autophagy-mediated chemoresistance in NSCLC remains unclear. Cisplatin-resistant cell lines (A549/DDP and H446/DDP) were transfected with related vectors and subjected to cisplatin, autophagy inhibitor, activator, or extracellular signal-regulated kinase (ERK) activator. Flow cytometry, CCK8 and colony formation assays were performed for testing apoptosis and cell viability. The related RNAs or proteins were detected by qRT-PCR or Western blot. Chromatin immunoprecipitation, luciferase reporter assay or RNA immunoprecipitation were used for validating the interaction between miR-152-3p and ELF1 or NCAM1. Co-IP verified the binding between NCAM1 and ERK. The role of miR-152-3p in cisplatin resistance of NSCLC was also validated in vivo. The results showed that miR-152-3p and ELF1 were decreased in NSCLC tissues. miR-152-3p reversed cisplatin resistance by inhibiting autophagy through NCAM1. NCAM1 promoted autophagy through the ERK pathway and facilitated cisplatin resistance. ELF1 positively regulated miR-152-3p level by directly interacting with miR-152-3p promoter. miR-152-3p targeted NCAM1 to regulate NCAM1 level and then affected the binding of NCAM1 to ERK1/2. ELF1 inhibited autophagy and reversed cisplatin resistance through miR-152-3p/NCAM1. miR-152-3p inhibited autophagy and cisplatin resistance of xenograft tumor in mice. In conclusion, our study revealed that ELF1 inhibited autophagy to attenuate cisplatin resistance through the miR-152-3p/NCAM1/ERK pathway in H446/DDP and A549/DDP cells, suggesting a potential novel treatment strategy for NSCLC.

The long non-coding RNA LIMT inhibits metastasis of hepatocellular carcinoma and is suppressed by EGF signaling

Background

The long non-coding RNA LIMT (lncRNA inhibiting metastasis) acts as a tumor suppressor factor in some cancers. However, the biological role of LIMT in hepatocellular carcinoma (HCC) has not been explored.

Methods and Results

Quantitative real-time PCR was performed to evaluate the expression of LIMT in HCC tissue. The effects of LIMT on tumor growth and metastasis were assessed by in vitro experiments, including colony formation and transwell assays, and in vivo in nude mouse models. Western blot analysis was used to evaluate the expression levels of proteins associated with epithelial-mesenchymal transition (EMT). LIMT expression was significantly lower in HCC than in normal liver tissue. Functionally, overexpression of LIMT repressed the proliferation, invasion, and EMT of HCC cells, while LIMT knockdown increased proliferation, invasion, and EMT of HCC cells in vitro. Furthermore, LIMT overexpression suppressed HCC growth and metastasis while silencing of LIMT had an opposite effect in vivo. Finally, LIMT overexpression reversed EGF-induced EMT.

Conclusions

Our results suggest that LIMT could play an anti-cancer effect in HCC and might be a potential novel therapeutic target in HCC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11033-022-07325-0.

Long Noncoding RNA and Circular RNA Expression Profiles of Monocyte-Derived Dendritic Cells in Autoimmune Hepatitis

Autoimmune hepatitis (AIH) is a chronic liver disease caused by disruption of liver immune homeostasis. The effect of dendritic cells (DCs) on the pathogenesis of AIH is not fully understood. Long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs) have been shown to play critical roles in the regulation of cell function. In this study, we analyzed the immunophenotypic characteristics of DCs in the peripheral blood. The percentage of mature DCs was higher in AIH patients than in healthy controls (HCs), and the proportion of mature DCs decreased after treatment. We isolated monocyte-derived DCs (moDCs) from the peripheral blood, obtained whole RNA-sequencing (RNA-seq) data for the moDCs from the two groups, and identified differentially expressed (DE) lncRNAs, circRNAs, miRNAs and mRNAs. In addition, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses for the DE mRNAs and constructed competing endogenous RNA (ceRNA) networks. ENST00000543334, hsa_circ_0000279, and hsa_circ_0005076 were selected and validated by RT-qPCR. These results provide a possible molecular mechanism of DCs in the pathogenesis of AIH and identify some potential therapeutic targets.

LncRNA LIMT (LINC01089) contributes to sorafenib chemoresistance via regulation of miR-665 and epithelial to mesenchymal transition in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the most malignant tumors worldwide and HCC patients often develop drug resisitene. Long non-coding RNAs (LncRNAs) are closely related to cell cycle, growth, development, differentiation, and apoptosis. Abnormally expressed lncRNAs have been proved to mediate drug resistance in tumor cells. However, the effect of LIMT on drug resistance has not been explored in HCC. In this study, we explored the effect of long non-coding RNA LIMT on drug resistance and its underlying mechanism in hepatocellular carcinoma (HCC). Our results showed that LncRNA LINC01089 (LIMT) expression is downregulated in 78.57% (44/56) of 56 HCC tumor tissue samples. LIMT expression is also downregulated in HCC cells compared with that in normal liver LO2 cells. Inhibition of LIMT increases the resistance to sorafenib and promotes cell invasion via regulation of epithelial to mesenchymal transition (EMT) in HCC. StarBase V3.0 was used to predict the potential binding site of miR-665 in . Furthermore, miR-665 participates in sorafenib resistance and also regulates the level of EMT-related proteins in HCC cells. A rescue experiment demonstrated that silencing of eliminats the inhibitory effect of the miR-665 inhibitor on sorafenib resistance in HCC cells. Taken together, our findings revealed that downregulation of LIMT increases the resistance of HCC to sorafenib via miR-665 and EMT. Therefore, LIMT, which serves as a therapeutically effective target, will provide new hope for the treatment of HCC.

MicroRNA-2355-5p Promotes the Proliferation of Head and Neck Squamous Cell Carcinoma via Suppressing NISCH Expression

Background. MicroRNAs (miRNAs) have emerged as crucial regulators in various cancers. However, the potential role of miR-2355-5p in head and neck squamous cell carcinoma (HNSC) remains unclear. Methods. Bioinformatics methods were implemented to find the candidate target gene of miR-2355-5p. Quantitative real-time PCR was performed to detect RNA expression levels of miR-2355-5p and NISCH, while western blot was carried out for the detection of protein levels of NISCH and cell cycle-related biomarkers. CCK-8, EdU staining, and flow cytometry were employed to measure cell proliferation and cell cycle progression. Dual-luciferase assay and RNA pulldown were conducted to verify the binding relationship between miR-2355-5p and NISCH. Results. The expression levels of miR-2355-5p and NISCH were, respectively, higher and lower in HNSC tissues than those in normal adjacent tissues. The transfection of the miR-2355-5p inhibitor suppressed cell proliferation by arresting the cells at the G1/S transition. The results of luciferase activity and RNA pulldown assays indicated that miR-2355-5p directly targeted the NISCH 3′-untranslated region. Furthermore, the effects of miR-2355-5p inhibition on cell proliferation were reversed after treatment with siRNA against NISCH. Conclusion. In summary, our findings indicate that miR-2355-5p promotes cell cycle progression in HNSC by targeting NISCH. Hence, targeting miR-2355-5p could be a promising therapeutic strategy for the treatment of HNSC