LncRNA XIST facilitates proliferation and epithelial-mesenchymal transition of colorectal cancer cells through targeting miR-486-5p and promoting neuropilin-2

Long Noncoding RNA X-Inactive Specific Transcript Facilitates Cellular Functions in Melanoma via miR-139-5p/ROCK1 Pathway

Purpose

Although X-inactive specific transcript (XIST) is known to play a critical role in the pathogenesis of melanoma, the mechanisms through which this remains unclear.

Methods

RNAseq, immunohistochemistry, and qRT-PCR were used to identify the levels of XIST, miR-139-5p, and Rho-Associated Coiled-Coil Containing Protein Kinase-1 (ROCK1) in melanoma tissues and cells. A subcellular fractionation assay was used to determine the location of XIST. CCK-8 and colony formation assays were used to evaluate cellular proliferation. Cell migration and wound healing assays were used to detect the effects on cell migration. RNA pull-down was used to confirm the interaction between XIST and miR-139-5p. Besides, the xenograft tumor experiment was performed to further verify the roles of XIST in melanoma.

Results

In this study, an increased level of XIST was revealed in melanoma tissues and cells, which was associated with higher TNM stage and positive lymph node metastasis. XIST was found to function as a “molecular sponge” of miR-139-5p to facilitate cellular functions. Moreover, these consequences could be partially reversed by inhibition of miR-139-5p. MiR-139-5p was found to target ROCK1 directly, leading to suppression of ROCK1 expression; this effect could be partially reversed by inhibiting XIST expression. Furthermore, the deletion of ROCK1 induced anti-oncogenic effects similar to those seen with knockout of XIST. Upregulation of miR-139-5p and knockdown of XIST could inhibit cell functions in melanoma.

Conclusion

Our findings suggested that the lncRNA XIST facilitates cellular functions in melanoma via the miR-139-5p/ROCK1 pathway.

Circular RNA circHUWE1 Is Upregulated and Promotes Cell Proliferation, Migration and Invasion in Colorectal Cancer by Sponging miR-486

Background

Emerging studies have revealed that circular RNAs (circRNAs) correlate with diverse diseases including cancers. However, little is known about the functions of circRNAs in colorectal cancer (CRC). In our previous research, downregulation of hsa_circ_0140388 (circHUEW1) has been detected in CRC tissues through high-throughput sequencing. However, the underlying mechanism by which circHUWE1 regulates the proliferation and apoptosis in CRC has not been investigated.

Materials and Methods

The levels of circHUWE1 in 58 pairs of CRC tissues and corresponding adjacent healthy tissues were detected by RT-qPCR. In addition, the effects of circHUWE1 on cell proliferation, apoptosis migration and invasion were evaluated by cell proliferation assays, flow cytometry, and transwell assays in HCT116 and SW480 cell lines respectively. Meanwhile, the dual-luciferase reporter system assay was used to explore the interaction between circHUWE1 and miR-486 (hsa-miR-486-5p).

Results

In this study, we demonstrate that the expression of circHUEW1 is upregulated in CRC tissues. High expression of circHUEW1 was significantly associated with lymphovascular invasion (P =0.036), lymph node metastasis (P =0.017), distant metastasis (P =0.024), and TNM stage (P =0.009). Moreover, the area under the curve (AUC) of the receiver operating characteristic (ROC) curve was 0.732, which indicated that circHUWE1 could serve as a potential biomarker in the detection of CRC. Silencing circHUWE1 significantly inhibited the proliferation, migration and invasion capacity of CRC cells in vitro. Mechanistically, we demonstrated that circHUWE1 could sponge miR-486 and the downregulation of miR-486 could reverse the cancer suppressive effects caused by silencing circHUWE1.

Conclusion

In this study, our results revealed that circHUWE1 may be a potential therapeutic target and diagnostic biomarker for CRC.

MicroRNA-486-5p and microRNA-486-3p: Multifaceted pleiotropic mediators in oncological and non-oncological conditions

Despite historically known as "junk" DNA, nowadays non-coding RNA transcripts (ncRNAs) are considered as fundamental players in various physiological and pathological conditions. Nonetheless, any alteration in their expression level has been reported to be directly associated with the incidence and aggressiveness of several diseases. MicroRNAs (miRNAs) are the well-studied members of the ncRNAs family. Several reports have highlighted their crucial roles in the post-transcriptional manipulation of several signaling pathways in different pathological conditions. In this review, our main focus is the multifaceted microRNA-486 (miR-486). miR-486-5p and miR-486-3p have been reported to have central roles in several types oncological and non-oncological conditions such as lung, liver, breast cancers and autism, intervertebral disc degeneration and metabolic syndrome, respectively. Moreover, we spotted the light onto the pleiotropic role of miR-486-5p in acting as competing endogenous RNA with other members of ncRNAs family such as long non-coding RNAs.

Long noncoding RNA DLGAP1-AS1 promotes cell proliferation in hepatocellular carcinoma via sequestering miR-486-5p

Hepatocellular carcinoma (HCC) is most prevalent tumor in liver and one of the most fatal cancers in the world. Long noncoding RNAs (lncRNAs) have been accepted as important regulators in carcinomas. But there are still many lncRNAs including DLGAP1-AS1 unannotated in HCC. First of all, GEPIA suggested that DLGAP1-AS1 presented high expression in HCC tissue samples relative to the normal tissues. Besides, overexpression of DLGAP1-AS1 was also proved in HCC cell lines. Moreover, DLGAP1-AS1 knockdown efficiently suppressed cell proliferation in HCC. Interestingly, miR-486-5p was predicted and validated to interact with DLGAP1-AS1, while the level of miR-486-5p was significantly increased In HCC after DLGAP1-AS1 knockdown. Moreover, we uncovered that ectopic expression of miR-486-5p induced suppression on HCC cell proliferation and that miR-486-5p inhibition offset the effect of DLGAP1-AS1 silence on HCC cell proliferation and apoptosis. Furthermore, H3F3B was identified as target of miR-486-5p and was therefore positively regulated by DLGAP1-AS1 in HCC. Of note, H3F3B upregulation partly revived the declined cell proliferative capacity in response to DLGAP1-AS1 knockdown. To conclude, DLGAP1-AS1 exerted its oncogenic role in HCC via miR-486-5p/H3F3B axis. Our new findings provided novel theoretical basis for discovery of therapeutic targets of HCC.

TCF-4 Regulated lncRNA-XIST Promotes M2 Polarization Of Macrophages And Is Associated With Lung Cancer

Background

Little is known about the biological function of long non-coding RNA X inactive specific transcript (lncRNA XIST) and its underlying mechanism in tumor-associated macrophage (TAM) polarization of lung cancer.

Materials and methods

The expression of lncRNA XIST in macrophages was detected by RT-qPCR. The function of lncRNA XIST on IL-4-induced M2 polarization was evaluated by transfection of shRNA and RT-qPCR or Western blotting detection of M2 specific markers. Contact between T-cell-specific transcription factor 4 (TCF-4) and lncRNA XIST was verified by bioinformatics and luciferase assay. The relation between lncRNA XIST and lung cancer was determined by bioinformatics.

Results

The expression of lncRNA XIST in THP-1-differentiated macrophages was significantly increased in M2 macrophages than M1 (P < 0.05). lncRNA XIST downregulation suppressed the IL-4-induced M2 polarization, inducing downregulation of M2 specific markers such as IL-10, Arg-1, and CD163. However, the suppression was aborted by overexpression of TCF-4. Mechanistically, lncRNA XIST was regulated by TCF-4 through direct binding. Additionally, lung cancer conditioned macrophages exhibited high expression of lncRNA XIST and lung cancer tissues highly expressed TCF-4, indicating TCF-4 regulated lncRNA XIST closely correlated with macrophage polarization and tumor progression of lung cancer.

Conclusion

Taken together, this study demonstrated the important role of TCF-4 regulated lncRNA XIST in regulating M2 polarization and gave a novel insight into the TAMs regulation and potential therapeutic target of lung cancer.

Downregulation of LncRNA-XIST inhibited development of non-small cell lung cancer by activating miR-335/SOD2/ROS signal pathway mediated pyroptotic cell death

LncRNA-XIST participated in the regulation of Non-small cell lung cancer (NSCLC) progression, but the underlying mechanisms are still unclear. This study showed that LncRNA-XIST aberrantly overexpressed in either NSCLC tissues or cell lines comparing to their paired control groups. Knock-down of LncRNA-XIST promoted NSCLC cell apoptosis and inhibited cell proliferation, which were reversed by synergistically treating cells with pyroptosis inhibitor Necrosulfonamide (NSA). In addition, knock-down of LncRNA-XIST also promoted reactive oxygen species (ROS) production and NLRP3 inflammasome activation. In parallel, ROS scavenger N-acetyl cysteine (NAC) abrogated the effects of downregulated LncRNA-XIST on NSCLC cell pyroptosis. Furthermore, miR-335 was the downstream target of LncRNA-XIST and overexpressed LncRNA-XIST increased SOD2 expression levels by sponging miR-335. Mechanistically, miR-335 inhibitor reversed the effects of downregulated LncRNA-XIST on ROS levels and cell pyroptosis, which were abrogated by synergistically knocking down SOD2. Taken together, knock-down of LncRNA-XIST inhibited NSCLC progression by triggering miR-335/SOD2/ROS signal pathway mediated pyroptotic cell death.

LncRNA XIST promotes extracellular matrix synthesis, proliferation and migration by targeting miR-29b-3p/COL1A1 in human skin fibroblasts after thermal injury

Background

Long noncoding RNAs (lncRNAs) have been reported to be associated with dermis process during burn wound healing. This study aimed to investigate the role of lncRNA X-inactive specific transcript (XIST) in human skin fibroblasts (HSF) and extracellular matrix (ECM) as well as the regulatory network of XIST/microRNA-29b-3p (miR-29b-3p)/collagen 1 alpha 1 (COL1A1).

Methods

The wound samples were collected from 25 patients with deep partial thickness burn at day 5 after burn. The thermal injured model was established using HSF cells. The expressions of XIST, miR-29b-3p and COL1A1 were measured by quantitative real-time polymerase chain reaction and western blot. ECM synthesis, cell proliferation and migration were detected by western blot, cell counting kit-8 and trans-well assays, respectively. The interaction between miR-29b-3p and XIST or COL1A1 was explored by bioinformatics analysis and luciferase reporter assay.

Results

The expressions of XIST and COL1A1 were enhanced but miR-29b-3p expression was decreased after thermal injury. XIST overexpression promoted ECM synthesis, cell proliferation and migration in thermal injured HSF cells. However, XIST knockdown played an opposite effect. miR-29b-3p overexpression inhibited ECM synthesis, cell proliferation and migration, which was reversed by XIST. COL1A1 silence suppressed ECM synthesis, cell proliferation and migration by miR-29b-3p targeting. Moreover, COL1A1 up-regulation weakened the effect of XIST silence on ECM synthesis and HSF cell function.

Conclusion

XIST promoted ECM synthesis, cell proliferation and migration by sponging miR-29b-3p and targeting COL1A1 in HSF cells after thermal injury, indicating the promoting role of XIST in wound healing.