Overexpression of miR-21-5p promotes proliferation and invasion of colon adenocarcinoma cells through targeting CHL1

CHL1 inhibits cell proliferation, migration and invasion by regulating the NF‑κB signaling pathway in colorectal cancer

Cell adhesion molecule close homolog of L1 (CHL1) is implicated in tumorigenesis of various malignancies. However, its role and underlying molecular mechanisms in colorectal cancer (CRC) remain unclear. The present study aimed to evaluate the specific biological functions and mechanisms of CHL1, in order to provide a theoretical basis for the use of CHL1 as a biological target in CRC. CHL1 expression was originally determined in CRC cell lines. Subsequently, CHL1 overexpression was induced by plasmid transfection in HT29 and SW480 cells, and cell proliferation, migration and invasion were evaluated using the Cell Counting Kit-8, clone formation, organoids formation and Transwell assays. Immunofluorescence and western blotting were performed to assess the protein expression of E-cadherin or N-cadherin. Differentially expressed genes (DEGs) were further evaluated using RNA-sequencing (RNA-seq) in HT29 and SW480 cells following CHL1 overexpression and functional enrichment analysis. Western blotting was performed to validate the expression of proteins related to the nuclear factor κB (NF-κB) signaling pathway. The TNMplot online database revealed the significant downregulation of CHL1 in CRC tissues. The results indicated that exogenous CHL1 overexpression significantly inhibited the proliferative, organoid-forming, migratory and invasive abilities of HT29 and SW480 cells, and increased E-cadherin protein expression. Additionally, CHL1 overexpression reduced xenograft tumor growth in vivo. RNA-seq and functional analysis revealed that DEGs in CHL1 overexpressing cells were mainly enriched in the NF-κB signaling pathway. The expression of p-p65 and p-p65/p65 ratio were significantly reduced in HT29 and SW480 cells, following CHL1 overexpression. Additionally, the inhibitory effects of CHL1 overexpression on CRC cell proliferation, organoid formation, migration and invasion were partially counteracted following the overexpression of p65 expression. Overall, the present study demonstrates that CHL1 inhibits CRC cell growth, migration and invasion through the inactivation of the NF-κB signaling pathway.

Highly expressed miR-144-3p promotes the proliferation, migration and invasion of colon carcinoma cells by activating the Wnt/β-catenin signaling pathway through targeting SFRP1

Background: To investigate the influence of miR-144-3p on the proliferation, migration and invasion of colon carcinoma by targeting secreted frizzled-related protein 1 (SFRP1) as well as of the Wnt/β-catenin signaling pathway. Methods: Based on the TCGA database, the association between the expression of miR-144-3p and the clinical information and prognosis of patients with colon carcinoma was examined, and SFRP1 was selected as the target gene for further studies based on bioinformatics prediction tools. CCK8 assay, wound healing assay and transwell invasion assay were employed to examine the impact of miR-144-3p on colon carcinoma cells. The regulation of SFRP1 by miR-144-3p was investigated using a dual-luciferase reporter system, and a rescue experiment was conducted to further elucidate whether miR-144-3p promotes the migration of colon carcinoma cells through targeting SFRP1 or not. The Wnt/β-catenin signaling pathway-mediated effect of miR-144-3p in colon carcinoma was finally validated through the targeting of SFRP1. Results: The bioinformatics analysis showed that the miR-144 expression levels were substantially greater in colon carcinoma tissue than in para-carcinoma tissue and were closely with clinical stage and prognosis. The findings obtained from the trial indicated that miR-144-3p substantially expressed in colon carcinoma tissue sample and the colon carcinoma cells, and the overexpressed miR-144-3p boosted the colon carcinoma cells' proliferation, migration and invasion. The results of dual-luciferase reporter gene assay revealed that miR-144-3p targeted SFRP1, and rescue experiment was carried out and its results indicated that miR-144-3p increased colon carcinoma cells' migration through targeting SFRP1. In addition, the molecular axis of miR-144-3p/SFRP1 may over-activate the Wnt/β-catenin signaling pathway. Conclusions: The present study has identified a novel malignant biological behavior, namely the ability of miR-144-3p to enhance the proliferation, migration and invasion of colon carcinoma cells by targeting SFRP1 and activating the Wnt/β-catenin signaling pathway. Consequently, miR-144-3p emerges as a promising diagnostic and therapeutic target for colon carcinoma.

Novel Approach to Enriching Glycosylated RNAs: Specific Capture of GlycoRNAs via Solid-Phase Chemistry

Ribonuclease (RNA) modifications can alter cellular function and lead to differential immune responses by acting as discriminators between RNAs from different phyla. RNA glycosylation has recently been observed at the cell surface, and its dysregulation in disease may change RNA functions. However, determining which RNA substrates can be glycosylated remains to be explored. Here, we develop a solid-phase chemoenzymatic method (SPCgRNA) for targeting glycosylated RNAs, by which glycosylated RNA substrates can be specifically recognized. We found the differential N-glycosylation of small RNAs in hTERT-HPNE and MIA PaCa-2 cancer cells using SPCgRNA. RNA-Seq showed that the changes in glyco-miRNAs prepared from SPCgRNA were consistent with those of traditional methods. The KEGG signaling pathway analysis revealed that differential miRNA glycosylation can affect tumor cell proliferation and survival. Further studies found that NGI-1 significantly inhibited the proliferation, migration, and circulation of MIA PaCa-2 and promoted cell apoptosis. In addition, β-1,4-galactosyltransferase 1 (B4GALT1) not only affected the expression level of glycosylated miRNAs hsa-miR-21-5p but also promoted cell apoptosis and inhibited the cell cycle possibly through the p53 signaling pathway, while B4GALT1 and p53 were also affected following the hsa-miR-21-5p increase. These results suggest that B4GALT1 may catalyze miRNAs glycosylation, which further promotes cancer cell progression.

miR-21-5p Inhibits the Proliferation, Migration, and Invasion of Glioma by Targeting S100A10

S100A10, a member of the S100 protein family, is upregulated in multiple human malignancies and plays a key role in regulating tumor progression. This study aimed to reveal the underlying mechanism by which S100A10 in regulates the proliferation, migration, and invasion of glioma. The expression and clinical information data of S100A10 were downloaded from public databases (TCGA, CGGA, and GEPIA2). S100A10 expression levels in glioma tumor tissues and adjacent nontumor tissues were compared by immunohistochemistry (IHC). The functional roles of S100A10 in glioma were assessed by cell counting kit-8 (CCK-8) cell proliferation assay, wound healing assay, transwell assay, and flow cytometry. miRDB and double luciferase assay were used to predict and identify potential S100A10 mRNA-complementary miRNAs, and the roles of miR-21-5p in glioma cell were examined by targeted knockdown or overexpression miR-21-5p in glioma cell lines. We found that S100A10 was overexpressed in glioma tissues and predicted a worse prognosis. S100A10 knockdown significantly inhibited glioma cell proliferation, invasion, and migration. Furthermore, we demonstrated that miR-21-5p inhibits glioma proliferation, migration, and invasion by targeting S100A10. This study showed S100A10 was a new prognostic predictor among glioma patients and provided new insights into the pathogenesis of gliomas, suggesting that miR-21-5p /S100A10 axis may serve as a valuable therapeutic target for glioma.

Identification of Key Biomarkers and Candidate Molecules in Non-Small-Cell Lung Cancer by Integrated Bioinformatics Analysis

Background

Non-small cell lung cancer (NSCLC) is the most prevalent malignant tumor of the lung cancer, for which the molecular mechanisms remain unknown. In this study, we identified novel biomarkers associated with the pathogenesis of NSCLC aiming to provide new diagnostic and therapeutic approaches for NSCLC by bioinformatics analysis.

Methods

From the Gene Expression Omnibus database, GSE118370 and GSE10072 microarray datasets were obtained. Identifying the differentially expressed genes (DEGs) between lung adenocarcinoma and normal samples was done. By using bioinformatics tools, a protein-protein interaction (PPI) network was constructed, modules were analyzed, and enrichment analyses were performed. The expression and prognostic values of 14 hub genes were validated by the GEPIA database, and the correlation between hub genes and survival in lung adenocarcinoma was assessed by UALCAN, cBioPortal, String and Cytoscape, and Timer tools.

Results

We found three genes (PIK3R1, SPP1, and PECAM1) that have a clear correlation with OS in the lung adenocarcinoma patient. It has been found that lung adenocarcinoma exhibits high expression of SPP1 and that this has been associated with poor prognosis, while low expression of PECAM1 and PIK3R1 is associated with poor prognosis (P < 0.05). We also found that the expression of SPP1 was associated with miR-146a-5p, while the high expression of miR-146a-5p was related to good prognosis (P < 0.05). On the contrary, the lower miR-21-5p on upstream of PIK3R1 is associated with a higher surviving rate in cancer patients (P < 0.05). Finally, we found that the immune checkpoint genes CD274(PD-L1) and PDCD1LG2(PD-1) were also related to SPP1 in lung adenocarcinoma.

Conclusions

The results indicated that SPP1 is a cancer promoter (oncogene), while PECAM1 and PIK3R1 are cancer suppressor genes. These genes take part in the regulation of biological activities in lung adenocarcinoma, which provides a basis for improving detection and immunotherapeutic targets for lung adenocarcinoma.

A reciprocal feedback between colon cancer cells and Schwann cells promotes the proliferation and metastasis of colon cancer

BACKGROUND

Research has indicated that the emergence of Schwann cells around premalignant lesions of colon cancer might be an early indicator promoting the onset of tumorigenesis. The present study explored the communication between colon cancer cells and Schwann cells.

METHODS

Immunofluorescence analyses were conducted to examine the differential distribution of Schwann cells within colon cancer tissues and normal colon tissues. CCK8 assay, colony formation assay, wound healing assay, and transwell assay were performed to investigate the interaction between colon cancer cells and Schwann cells. Exosomes derived from colon cancer cells were isolated to further explore the effect of colon cancer cells on Schwann cells. Gain- and loss-of function experiments, luciferase reporter assays, chromatin immunoprecipitation assays, and immunohistochemistry assays were performed to reveal the cross-talk between colon cancer cells and Schwann cells. Furthermore, colon cancer cells co-cultured with Schwann cells were transplanted into nude mice for evaluating their effect on tumor proliferation and metastasis in vivo.

RESULTS

The clinicopathological characteristics indicated that Schwann cells were enriched in colon cancer tissues and were associated with tumor metastasis and poor prognosis. The co-culture of Schwann cells with colon cancer cells promoted the proliferation and migration of colon cancer cells and Schwann cells, which was mediated by nerve growth factor (NGF) secreted from Schwann cells. Exosomal miR-21-5p released by colon cancer cells inhibited VHL expression in Schwann cells, which in turn stabilized the HIF-1α protein and increased the transcription of NGF. Meanwhile, the Schwann cells-derived NGF activated TrkA/ERK/ELK1/ZEB1 signaling pathway in colon cancer cells, which further enhanced the expression of exosomal miR-21-5p. Inhibition of either NGF or miR-21-5p significantly inhibited the proliferation and metastasis of transplanted colon cancer cells in nude mice. Coincidently, miR-21-5p was positively associated with the expression of NGF, p-ERK, p-ELK1, and ZEB1 in human colon cancer tissues.

CONCLUSIONS

Our results implicated a reciprocal communication between colon cancer cells and Schwan cells that promoted the proliferation and metastasis of colon cancer, and identified NGF and exosomal miR-21-5p as potential therapeutic targets for the treatment of colon cancer.

lncRNA NBAT1 Inhibits Cell Metastasis and Promotes Apoptosis in Endometrial Cancer by Sponging miR-21-5p to Regulate PTEN

Objective

Long noncoding RNA neuroblastoma-associated transcript 1 (NBAT1) is implicated in the progression of various cancers. Nevertheless, its biological function in endometrial cancer (EC) remains unknown.

Methods

The levels of NBAT1, miR-21-5p, and PTEN in EC cells and EC tissues were examined by RT-qPCR. Western blot was carried out to assess the protein expression of PTEN. The dual-luciferase reporter assay was conducted to explore the interactions among NBAT1, miR-21-5p, and PTEN. The effect of NBAT1 on EC proliferation, metastasis, and apoptosis was evaluated by CCK-8, transwell assays, wound healing, and flow cytometry. miR-21-5p mimics or NBAT1+miR-21-5p were transfected into HEC-1A and Ishikawa cells to investigate whether NBAT1 regulated EC tumorigenesis via sponging miR-21-5p.

Results

NBAT1 is downregulated, and miR-21-5p is upregulated in EC cells and tumor tissues. Overexpression of NBAT1 inhibits the proliferation, migration, and invasion abilities of EC cells and facilitated apoptosis. NBAT1 directly binds and negatively regulates miR-21-5p in EC. miR-21-5p mimics reverses the effect of lncRNA NBAT1 overexpression on the proliferation and migration of EC cells. PTEN is a downstream gene of miR-21-5p. lncRNA NBTA1 elevates PTEN expression via sponging miR-21-5p.

Conclusions

lncRNA NBAT1 acts as a tumor suppressor in EC via regulating PTEN through sponging miR-21-5p.

Application of Bidirectional Generative Adversarial Networks to Predict Potential miRNAs Associated With Diseases

Substantial evidence has shown that microRNAs are crucial for biological processes within complex human diseases. Identifying the association of miRNA–disease pairs will contribute to accelerating the discovery of potential biomarkers and pathogenesis. Researchers began to focus on constructing computational models to facilitate the progress of disease pathology and clinical medicine by identifying the potential disease-related miRNAs. However, most existing computational methods are expensive, and their use is limited to unobserved relationships for unknown miRNAs (diseases) without association information. In this manuscript, we proposed a creatively semi-supervised model named bidirectional generative adversarial network for miRNA-disease association prediction (BGANMDA). First, we constructed a microRNA similarity network, a disease similarity network, and Gaussian interaction profile kernel similarity based on the known miRNA–disease association and comprehensive similarity of miRNAs (diseases). Next, an integrated similarity feature network with the full underlying relationships of miRNA–disease pairwise was obtained. Then, the similarity feature network was fed into the BGANMDA model to learn advanced traits in latent space. Finally, we ranked an association score list and predicted the associations between miRNA and disease. In our experiment, a five-fold cross validation was applied to estimate BGANMDA’s performance, and an area under the curve (AUC) of 0.9319 and a standard deviation of 0.00021 were obtained. At the same time, in the global and local leave-one-out cross validation (LOOCV), the AUC value and standard deviation of BGANMDA were 0.9116 ± 0.0025 and 0.8928 ± 0.0022, respectively. Furthermore, BGANMDA was employed in three different case studies to validate its prediction capability and accuracy. The experimental results of the case studies showed that 46, 46, and 48 of the top 50 prediction lists had been identified in previous studies.

Modulation of microRNAs and claudin-7 in Caco-2 cell line treated with Blastocystis sp., subtype 3 soluble total antigen

Background

Blastocystis sp., is a eukaryote of the large intestine, which is reported from almost all countries. The pathogenesis of this protist is not clear. The current study aimed to analyze the effects of Blastocystis sp., ST3 soluble total antigen (B3STA) on the microRNAs (miRNAs) involved in the gut permeability and also pro-inflammatory cytokines, occludin, and claudin-7.

Methods

Blastocystis sp., ST3 isolated from stool sample was purified, and its soluble total antigen was extracted using freeze and thawing. The Caco-2 cell line was treated with B3STA for 24 h and the expression levels of mir-16, mir-21, mir-29a, mir-223, and mir-874 were analyzed. In addition, the expression levels of il-8, il-15, occludin, and claudin-7 genes were assessed.

Results

B3STA significantly upregulated the expression of mir-223, and mir-874, and downregulated mir-29a. The expression of mir-16 and mir-21 was not significant. In addition, the expression of il-8 and il-15 was not significant. B3STA significantly decreased the expression level of claudin-7 (P-value < 0.0001), but the expression of occludin was not significant. Our results showed significant correlation between all studied miRNAs, except mir-29a, with downregulation of claudin-7.

Conclusions

This is the first study investigating the effects of Blastocystis sp., ST3 isolated from symptomatic subjects on the expression levels of miRNAs involved in the gut permeability. Our results demonstrated that B3STA may change miRNA expression, which are involved in the gut barrier integrity, and downregulates claudin-7, which is known as sealing factor.

Nanomaterial Exposure, Extracellular Vesicle Biogenesis and Adverse Cellular Outcomes: A Scoping Review

The progressively increasing use of nanomaterials (NMs) has awakened issues related to nanosafety and its potential toxic effects on human health. Emerging studies suggest that NMs alter cell communication by reshaping and altering the secretion of extracellular vesicles (EVs), leading to dysfunction in recipient cells. However, there is limited understanding of how the physicochemical characteristics of NMs alter the EV content and their consequent physiological functions. Therefore, this review explored the relevance of EVs in the nanotoxicology field. The current state of the art on how EVs are modulated by NM exposure and the possible regulation and modulation of signaling pathways and physiological responses were assessed in detail. This review followed the manual for reviewers produced by The Joanna Brigs Institute for Scoping Reviews and the PRISMA extension for Scoping Reviews (PRISMA-ScR): checklist and explanation. The research question, "Do NMs modulate cellular responses mediated by EVs?" was analyzed following the PECO model (P (Population) = EVs, E (Exposure) = NMs, C (Comparator) = EVs without exposure to NMs, O (Outcome) = Cellular responses/change in EVs) to help methodologically assess the association between exposure and outcome. For each theme in the PECO acronym, keywords were defined, organized, and researched in PubMed, Science Direct, Scopus, Web of Science, EMBASE, and Cochrane databases, up to 30 September 2021. In vitro, in vivo, ex vivo, and clinical studies that analyzed the effect of NMs on EV biogenesis, cargo, and cellular responses were included in the analysis. The methodological quality assessment was conducted using the ToxRTool, ARRIVE guideline, Newcastle Ottawa and the EV-TRACK platform. The search in the referred databases identified 2944 articles. After applying the eligibility criteria and two-step screening, 18 articles were included in the final review. We observed that depending on the concentration and physicochemical characteristics, specific NMs promote a significant increase in EV secretion as well as changes in their cargo, especially regarding the expression of proteins and miRNAs, which, in turn, were involved in biological processes that included cell communication, angiogenesis, and activation of the immune response, etc. Although further studies are necessary, this work suggests that molecular investigations on EVs induced by NM exposure may become a potential tool for toxicological studies since they are widely accessible biomarkers that may form a bridge between NM exposure and the cellular response and pathological outcome.

Hsa_circ_0008259 modulates miR-21-5p and PDCD4 expression to restrain osteosarcoma progression

BACKGROUND

Osteosarcoma (OS) is one of the most common primary bone tumors in children and adolescents. However, the molecular mechanism of OS tumorigenesis is still little known. Circular RNA (circRNA) is a key player in the progression of many cancers. This study is performed to decipher the role and mechanism of circ_0008259 in the progression of OS.

METHODS

A differentially expressed circRNA, circ_0008259, was screened out by analyzing the expression profile of circRNA in OS tissue. Circ_0008259, miR-21-5p and programmable cell death 4 (PDCD4) mRNA expression levels in OS tissues and cells were detected by qRT-PCR. Cell viability, metastatic potential and apoptosis were evaluated by cell counting kit-8 assay, Transwell and flow cytometry. The targeting relationship between circ_0008259 and miR-21-5p, and miR-21-5p and PDCD4 mRNA was analyzed and probed by bioinformatics analysis and dual-luciferase reporter assay, RNA-binding protein immunoprecipitation assay and RNA-pull down assay. The regulatory effects of circ_0008259 and miR-21-5p on PDCD4 protein expression in OS cells were detected by Western blot assay.

RESULTS

Circ_0008259 expression and PDCD4 expression were down-regulated and miR-21-5p expression was elevated in the OS tissues and cells. Functional experiments showed that circ_0008259 overexpression significantly inhibited the proliferation and metastatic potential of OS cells and promoted the apoptosis. Besides, PDCD4 was validated as the target gene of miR-21-5p, and circ_0008259 could competitively bind to miR-21-5p, thus up-regulating PDCD4 expression in OS cells.

CONCLUSIONS

Circ_0008259 suppresses OS progression via regulating miR-21-5p/PDCD4 axis.

Exosomal miR-21-5p derived from cisplatin-resistant SKOV3 ovarian cancer cells promotes glycolysis and inhibits chemosensitivity of its progenitor SKOV3 cells by targeting PDHA1

Ovarian cancer (OC) is a common reason for gynecologic cancer death. Standard treatments of OC consist of surgery and chemotherapy. However, chemoresistance should be considered. Exosomal miR-21-5p has been shown to regulate the chemosensitivity of cancer cells through regulating pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1). However, the role of miR-21-5p/PDHA1 in OC is unclear. The levels of miR-21-5p and PDHA1 in clinical samples and cells were investigated. Exosomes derived from SKOV3/cisplatin (SKOV3/DDP) cells (DDP-Exos) were isolated and used to treat SKOV3 cells to test DDP-Exos effects on SKOV3 cells. Extracellular acidification rate and oxygen consumption rate were tested with a Seahorse analyzer. Cell apoptosis was analyzed by a flow cytometer. PDHA1 was overexpressed and miR-21-5p was silenced in SKOV3 cells to study the underlying mechanism of miR-21-5p in OC. Quantitative real-time PCR and immunoblots were applied to measure gene expression at mRNA and protein levels. The levels of PDHA1 in DDP-resistant SKOV3 or tumor tissues were significantly decreased while the levels of miR-21-5p were remarkably upregulated. miR-21-5p in DDP-Exos was sharply increased compared to that of Exos. Data also indicated that DDP-Exos treatment suppressed the sensitivity of SKOV3 cells to DDP and promoted cell viability and glycolysis of SKOV3 cells through inhibiting PDHA1 by exosomal miR-21-5p. miR-21-5p derived from DDP-resistant SKOV3 OC cells promotes glycolysis and inhibits chemosensitivity of its progenitor SKOV3 cells by targeting PDHA1. Our data highlights the important role of miR-21-5p/PDHA1 axis in OC and sheds light on new therapeutic development.

Predictive Efficacy of MiR-125b-5p, MiR-17-5p, and MiR-185-5p in Liver Metastasis and Chemotherapy Response Among Advanced Stage Colorectal Cancer Patients

MicroRNAs (miRNAs), a class of small non-coding RNAs represent potential biomarkers for colorectal cancer (CRC). The study hypothesized that miRNAs associated with liver metastases may also contribute to assessing treatment response when associated to plasma exosomes. In this study, we used two sets of biological samples, a collection of tumor tissues harvested from patients with CRC with and without liver metastases, and a collection of plasma from CRC patients with and without response to FOLFOX4/FOLFIRI regimens. We investigated 10 target miRNAs in the tissue of 28 CRC patients and identified miR-125b-5p, miR-17-5p, and miR-185-5p to be associated with liver metastasis. Further, we investigated the three miRNAs at the exosomal level in a plasma collection to test their association with chemotherapy response. Our data suggest that the elevated plasma levels of miR-17-5p and miR-185-5p could be predictive of treatment response. Overexpression of miR-17-5p and underexpression of miR-125b-5p and miR-185-5p in CRC tissue seem to be associated with metastatic potential. On the other hand, an increased expression of miR-125b-5p in plasma exosomes was potentially correlated with a more aggressive CRC phenotype.

Ozone oil promotes wound healing via increasing miR-21-5p-mediated inhibition of RASA1

Skin wound is a very common type of injury and the healing process greatly affects the life quality of individuals. Ozone has been shown beneficial to wound healing with unclear mechanisms. Here, we tested the effect of ozone oil (OZ) on wound healing and investigated the underlying mechanisms. Mouse skin wound model and Masson staining were used to evaluate the effect of OZ on wound healing. Primary fibroblast culture was employed to assess the functions of OZ, miR-21-5p, and RASA1. QRT-PCR and western blot were used to determine expression levels of miR-21-5p, RASA1, α-SMA, and collagen I. CCK-8 assay and scratch wound healing assay were used to measure viability and migration of fibroblasts. Dual luciferase activity assay was performed to validate miR-21-5p/RASA1 interaction. OZ accelerated wound healing in mice and promoted proliferation and migration abilities of fibroblasts. miR-21-5p was increased while RASA1 was reduced during the wound healing and OZ treatment augmented those changes, as well as increased levels of α-SMA and collagen I. Knockdown of miR-21-5p suppressed those effects of OZ on fibroblasts. Furthermore, miR-21-5p directly targeted RASA1 mRNA and negatively regulated its expression. Overexpression of RASA1 inhibited fibroblast proliferation and migration as well as diminished α-SMA and collagen I protein expression. Additionally, RASA1 overexpression blocked the promotion of miR-21-5p overexpression on fibroblast viability and migration. In vivo, miR-21-5p facilitated wound healing while overexpression of RASA1 reversed the effect. OZ promoted wound healing by enhancing miR-21-5p-mediated RASA1 inhibition to increase fibroblast proliferation and migration.

LncRNA OTUD6B-AS1 inhibits many cellular processes in colorectal cancer by sponging miR-21-5p and regulating PNRC2

Accumulating evidence has revealed that long noncoding RNAs (lncRNAs) play essential roles in regulating cellular process of various cancers. There have been many studies on the biological functions of lncRNAs in colorectal cancer (CRC). In this research, we explored the role and mechanism of lncRNA ovarian tumor domain containing 6B antisense RNA1 (OTUD6B-AS1) in CRC. Here, we detected OTUD6B-AS1 expression in CRC tissues and cells by RT-qPCR. Functional experiments were performed to test alterations in different cellular processes. Moreover, to verify the binding ability among the indicated RNA molecules, we carried out RIP, RNA pull-down and luciferase reporter assays. According to our data, OTUD6B-AS1 expression was low in CRC tissues and cells. Functionally, overexpression of OTUD6B-AS1 inhibited cell proliferation, migration, invasion and EMT, and promoted cell apoptosis. Bioinformatic analysis and mechanistical experiments confirmed that OTUD6B-AS1 could act as a competitive endogenous RNA (ceRNA) to upregulate Proline-Rich Nuclear Receptor Coactivator 2 (PNRC2) expression by sequestering miR-21-5p. Further rescue experiments validated the inhibitory function of the OTUD6B-AS1/miR-21-5p/PNRC2 axis in cellular process of CRC. Overall, OTUD6B-AS1 inhibits cellular development in CRC by sponging miR-21-5p and upregulating PNRC2, providing a novel insight into the exploration on CRC treatment.

Identification of microRNA-Associated-ceRNA Networks Regulating Crop Milk Production in Pigeon (Columba livia)

Pigeon belongs to altrices. Squab cannot forage independently. Nutrition can only be obtained from crop milk secreted by male and female pigeon. miRNA could regulate many biological events. However, the roles of miRNA and ceRNA in regulating crop milk production are still unknown. In this study, we investigated the miRNAs expression profile of female pigeon crop, explored the potential key genes, and found the regulatory mechanisms of crop milk production. A total of 71 miRNAs were identified differentially expressed significantly. Meanwhile, miR-20b-5p, miR-146b-5p, miR-21-5p, and miR-26b-5p were found to be the key miRNAs regulating lactation. Target genes of these miRNAs participated mainly in cell development; protein and lipid synthesis; and ion signaling processes, such as cell-cell adhesion, epithelial cell morphogenesis, calcium signaling pathway, protein digestion, and absorption. In the ceRNA network, miR-193-5p was located in the central position, and miR-193-5p/CREBRF/LOC110355588, miR-460b-5p/GRHL2/MSTRG.132954, and miR-193-5p/PIK3CD/LOC110355588 regulatory axes were believed to affect lactation. Collectively, our findings enriched the miRNA expression profile of pigeon and provided novel insights into the microRNA-associated-ceRNA networks regulating crop milk production in pigeon.

Role of miRNAs in Sigmoid Colon Cancer: A Search for Potential Biomarkers

The aberrant expression of microRNAs in known to play a crucial role in carcinogenesis. Here, we evaluated the miRNA expression profile of sigmoid colon cancer (SCC) compared to adjacent-to-tumor (ADJ) and sigmoid colon healthy (SCH) tissues obtained from colon biopsy extracted from Brazilian patients. Comparisons were performed between each group separately, considering as significant p-values < 0.05 and |Log2(Fold-Change)| > 2. We found 20 differentially expressed miRNAs (DEmiRNAs) in all comparisons, two of which were shared between SCC vs. ADJ and SCC vs. SCH. We used miRTarBase, and miRTargetLink to identify target-genes of the differentially expressed miRNAs, and DAVID and REACTOME databases for gene enrichment analysis. We also used TCGA and GTEx databases to build miRNA-gene regulatory networks and check for the reproducibility in our results. As findings, in addition to previously known miRNAs associated with colorectal cancer, we identified three potential novel biomarkers. We showed that the three types of colon tissue could be clearly distinguished using a panel composed by the 20 DEmiRNAs. Additionally, we found enriched pathways related to the carcinogenic process in which miRNA could be involved, indicating that adjacent-to-tumor tissues may be already altered and cannot be considered as healthy tissues. Overall, we expect that these findings may help in the search for biomarkers to prevent cancer progression or, at least, allow its early detection, however, more studies are needed to confirm our results.

Close homolog of L1-deficient ameliorates inflammatory bowel disease by regulating the balance of Th17/Treg

OBJECTIVE

The aim of this study is to investigate the role of close homolog of L1 (CHL1) on inflammatory bowel disease (IBD), and the correlation with the balance of Th17/Treg.

METHODS

Dextran sodium sulfate (DSS)-induced IBD mice model was established. CHL1 knockout (KO) mice and CHL1 wild-type (WT) mice were subjected to DSS. CHL1 expression was detected using qRT-PCR. Weight was recorded daily, and disease activity index (DAI) score was assessed. The colon length and histological changes were measured. The number of neutrophils, macrophages and T cells was observed by immunohistochemistry. The expression of inflammatory cytokines and the proportion of Th17/Treg cells were detected by qRT-PCR and flow cytometry. The expression of RORγt, STAT3 and Foxp3 was detected by using immunohistochemistry and Western blot.

RESULTS

CHL1 expression was upregulated in DSS-induced IBD mice. DSS-CHLl-KO mice exhibited less weight loss than the DSS-CHLl-WT mice. The DAI score and histological score were decreased in DSS-CHLl-KO mice compared with DSS-CHLl-WT mice, while colon length was increased. Number of neutrophils, macrophages and T cells, and expression of TNF-α, IL-6, IL-17A, IL-21 and IL-23 were decreased in DSS-CHLl-KO mice, while IL-10 expression was increased. Moreover, CHL1-deficient inhibited Th17 cells differentiation and promoted Treg cells differentiation in IBD mice. CHL1-deficient also inhibited the expression of RORγt and STAT3, and promoted the expression of Foxp3 in IBD mice.

CONCLUSION

CHL1-deficient reduces the inflammatory response by regulating the balance of Th17/Treg in mice with IBD. CHL1 is expected to be a new target for the treatment of IBD.

Mesenchymal stem cells-derived exosomal microRNA-21-5p downregulates PDCD4 and ameliorates erectile dysfunction in a rat model of diabetes mellitus

Erectile dysfunction (ED) is a common comorbidity in males with diabetes mellitus (DM), whose pathogenesis might be induced by dysregulation of corpus cavernosum smooth muscle cells (CCSMCs). Gene Expression Omnibus repository-based analysis identified the differentially expressed PDCD4 in DM rats. PDCD4 has also been determined as a putative gene under the regulatory control of microRNA-21-5p (miR-21-5p). This study aimed to further determine the functional role of miR-21-5p in CCSMCs in a rat model of diabetes mellitus-induced erectile dysfunction (DMED). CCSMCs were isolated from penile cavernous tissue and cultured in high glucose (HG) medium. The expression of miR-21-5p and/or PDCD4 was altered in CCSMCs, as directly or indirectly measured by CCK-8 assay, flow cytometry, and TUNEL assays. Furthermore, exosomes were isolated from mesenchymal stem cells (MSCs) transfected with miR-21-5p mimic or miR-21-5p inhibitor and co-cultured with CCSMCs. DMED rats were injected with lentivirus carrying PDCD4/siRNA-PDCD4 plasmids, or exosomes from MSCs containing miR-21-5p-agomir to explore their roles in vivo. The experimental data validated that PDCD4 was upregulated in cavernous tissue of DMED rats. miR-21-5p targeted and inhibited PDCD4. miR-21-5p was enriched in MSC-exosomes. Moreover, PDCD4 downregulation, miR-21-5p elevation or MSC-derived exosomal miR-21-5p reduced apoptosis and enhanced proliferation of CCSMCs cultured in HG medium. PDCD4 silencing or miR-21-5p-containing MSC-exosomes improved erectile function and smooth muscle density in DMED rats. Collectively, our findings suggested that MSC-derived exosomal miR-21-5p suppressed PDCD4 expression and ED in rats with DM.

Overexpression of close homolog of L1 enhances the chemosensitivity of lung cancer cells via inhibition of the Akt pathway

Drug resistance leads to tumor relapse and further progression during chemotherapy in lung cancer. Close homolog of L1 (CHL1) has been identified as a tumor suppressor in most malignancies. However, to the best of our knowledge, whether CHL1 mediates chemoresistance remains unknown. The present study observed that CHL1 was significantly downregulated in cisplatin (DDP)-resistant cells (A549/DDP) and paclitaxel (PTX)-resistant cells (A549/PTX) compared with A549 cells. When treated with or without DDP and PTX, silencing of CHL1 in A549 cells promoted the cell survival rate and clone formation, and decreased apoptosis. Whereas overexpression of CHL1 in A549/DDP and A549/PTX cells impeded the cell survival and clone formation and promoted apoptosis. Additionally, CHL1 overexpression enhanced the chemosensitivity of A549/DDP cells to DDP in vivo. Notably, the chemoresistance induced by CHL1 depletion was reversed by the Akt inhibitor SC66 in A549 cells. The results of the present study demonstrated that CHL1 enhanced sensitivity of lung cancer cells by suppressing the Akt pathway, which suggested that CHL1 may be a potential target for overcoming chemoresistance in lung cancer.

Curcumin Suppresses Cell Proliferation, Migration, and Invasion Through Modulating miR-21-5p/SOX6 Axis in Hepatocellular Carcinoma

Background: Curcumin is the major component of turmeric, which has an anticancer property in multiple cancers, including hepatocellular carcinoma (HCC). However, the mechanisms are still largely unclear. This research aims to assess the pharmacological function of curcumin and explore the potential microRNA (miRNA)-mRNA regulatory mechanism in curcumin-mediated HCC progression. Materials and Methods: Hep3B and Huh-7 cells were used for in vitro experiments. Cells were exposed to various doses of curcumin, and transfection was conducted using Lipofectamine 2000. Cell proliferation, migration, and invasion were examined using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide or transwell assay. The abundances of miR-21-5p and gender-determining region Y-related high-mobility group box 6 (SOX6) were examined using quantitative real-time polymerase chain reaction or Western blot. The relationship between miR-21-5p and SOX6 was analyzed through luciferase reporter analysis. Results: Curcumin repressed HCC cell proliferation, migration, and invasion. miR-21-5p level was decreased in curcumin-treated cells, and miR-21-5p overexpression reversed curcumin-mediated inhibition of HCC progression. SOX6 was targeted through miR-21-5p, and SOX6 restoration attenuated miR-21-5p-induced promotion of HCC progression. Moreover, curcumin exposure increased SOX6 expression through regulating miR-21-5p, and knockdown of SOX6 overturned curcumin-modulated suppression of HCC progression. Conclusions: Curcumin repressed proliferation, migration, and invasion of HCC cells by regulating miR-21-5p and SOX6, indicating the promisingly pharmacological effect of curcumin in HCC.

Inflamma-miR-21 Negatively Regulates Myogenesis during Ageing

Ageing is associated with disrupted redox signalling and increased circulating inflammatory cytokines. Skeletal muscle homeostasis depends on the balance between muscle hypertrophy, atrophy and regeneration, however during ageing this balance is disrupted. The molecular pathways underlying the age-related decline in muscle regenerative potential remain elusive. microRNAs are conserved robust gene expression regulators in all tissues including skeletal muscle. Here, we studied satellite cells from adult and old mice to demonstrate that inhibition of miR-21 in satellite cells from old mice improves myogenesis. We determined that increased levels of proinflammatory cytokines, TNFα and IL6, as well as H₂O₂, increased miR-21 expression in primary myoblasts, which in turn resulted in their decreased viability and myogenic potential. Inhibition of miR-21 function rescued the decreased size of myotubes following TNFα or IL6 treatment. Moreover, we demonstrated that miR-21 could inhibit myogenesis in vitro via regulating IL6R, PTEN and FOXO3 signalling. In summary, upregulation of miR-21 in satellite cells and muscle during ageing may occur in response to elevated levels of TNFα and IL6, within satellite cells or myofibrillar environment contributing to skeletal muscle ageing and potentially a disease-related decline in potential for muscle regeneration.

Expression and serum levels of the neural cell adhesion molecule L1-like protein (CHL1) in gastrointestinal stroma tumors (GIST) and its prognostic power

INTRODUCTION

Diagnosis of gastrointestinal stroma tumors (GIST) is based on the histological evaluation of tissue specimens. Reliable systemic biomarkers are lacking. We investigated the local expression of the neural cell adhesion molecule L1-like protein (CHL1) in GIST and determined whether soluble CHL1 proteoforms could serve as systemic biomarkers.

MATERIAL AND METHODS

Expression of CHL1 was analyzed in primary tumor specimens and metastases. 58 GIST specimens were immunohistochemically stained for CHL1 on a tissue microarray (TMA). Systemic CHL1 levels were measured in sera derived from 102 GIST patients and 91 healthy controls by ELISA. Results were statistically correlated with clinicopathological parameters.

RESULTS

CHL1 expression was detected in GIST specimens. Reduced tissue expression was significantly associated with advanced UICC stages (p = 0.036) and unfavorable tumor localization (p = 0.001). CHL1 serum levels are significantly elevated in GIST patients (p < 0.010). Elevated CHL1 levels were significantly associated with larger tumors (p = 0.023), advanced UICC stage (p = 0.021), and an increased Fletcher score (p = 0.041). Moreover, patients with a higher CHL1 serum levels displayed a significantly shortened recurrence free survival independent of other clinicopathological variables.

CONCLUSION

Local CHL1 expression and serum CHL1 levels show a reverse prognostic behavior, highlighting the relevance of proteolytic shedding of the molecule. The results of the study indicate a potential role of serum CHL1 as a diagnostic and prognostic marker in GIST.

miR-21-5p promotes cell proliferation and G1/S transition in melanoma by targeting CDKN2C

Human melanoma is a highly malignant tumor originating from cutaneous melanocytes. The noncoding RNA microRNA (miR)‐21‐5p has been reported to be expressed at high levels in malignant melanocytic skin tissues, but its potential functional role in melanoma remains poorly understood. Here, we explored the cellular effects of miR‐21‐5p on melanoma in vitro and the underlying mechanisms. Quantitative real‐time PCR was used to show that miR‐21‐5p is significantly up‐regulated in clinical samples from patients with melanoma as compared with adjacent noncancerous tissues. Overexpression of miR‐21‐5p significantly enhanced, whereas knockdown attenuated, cell proliferation and G1/S transition in melanoma cell lines (A375 and M14). Luciferase reporter assays were used to show that the cyclin‐dependent kinase inhibitor 2C (CDKN2C) is a downstream target of miR‐21‐5p. Furthermore, miR‐21‐5p mimics resulted in a decrease in CDKN2C expression, and CDKN2C expression was observed to be inversely correlated with miR‐21‐5p expression in melanoma tissues. Rescue experiments were performed to show that overexpression of CDKN2C partially reversed the effects of miR‐21‐5p up‐regulation on A375 cells. Consistently, knockdown of CDKN2C abolished the effects of miR‐21‐5p down‐regulation on A375 cells. Overall, our studies demonstrate that miR‐21‐5p can promote the growth of melanoma cells by targeting CDKN2C, which may induce G0/G1 phase arrest of melanoma cells.

MicroRNA-1249 targets four-jointed box kinase 1 and reduces cell proliferation, migration and invasion of colon adenocarcinoma

BACKGROUND

MiR-1249 was demonstrated to be dysregulated and related to prognosis in cancers. It has been reported to be significantly down-regulated in colon adenocarcinoma (COAD). The present study aimed to explore the clinical value and biological roles of miR-1249 in the progression of COAD.

METHODS

miRWalk was applied to predict potential targets of miR-1249. We investigated the expression patterns of miR-1249 and its potential target Four-Jointed Box Kinase 1 (FJX1) in COAD samples from The Cancer Genome Atlas (TCGA) or ONCOMINE database. Kaplan-Meier with a log-rank test was used to reveal the relationship between overall survival (OS) and miR-1249/FJX1. The predictive ability of miR-1249/FJX1 was investigated using univariate and multivariate Cox regression models. CCK-8 and Transwell assays were performed to determine whether miR-1249 was connected with cell viability, migration and invasion. A luciferase reporter assay was applied to verify the association of miR-1249 and FJX1 as its predicted target gene.

RESULTS

We predicted and confirmed FJX1 to be a target gene of miR-1249. MiR-1249 was down-regulated in COAD samples and cell lines. Univariate and multivariate analysis showed that the expression of FJX1 could be regarded as independent predictor for COAD. Moreover, miR-1249 and FJX1 were respectively the indicators of favorable and poor OS. MiR-1249 over-expression repressed cell growth, migration and invasion. Overexpression of FJX1 in cells treated with miR-1249 mimic abolished the inhibitory effect of miR-1249 on cell growth, migration and invasion.

CONCLUSIONS

miR-1249 exerts a suppressive effect on cell proliferation, migration and invasion in COAD, which is possibly achieved via modulating FJX1.

ROS-mediated miR-21-5p regulates the proliferation and apoptosis of Cr(VI)-exposed L02 hepatocytes via targeting PDCD4

Although much has been determined about the molecular mechanisms of hexavalent chromium [Cr(VI)]-induced hepatotoxicity, more remains to be explored. In particular, explicit epigenetic alterations of microRNAs (miRNAs) which can negatively regulate mRNAs at post transcriptional level remain understudied. In the present study, cell apoptosis was determined using Annexin V/propidium iodide (PI) staining, while proliferative growth was analyzed by colony formation assay and proliferating cell nuclear antigen (PCNA) detection. miRNA microarray was performed to compare the global miRNAs expression patterns. miR-21-5p mimics (mi)/inhibitor (in), and PDCD4-siRNAs were transfected into L02 hepatocytes. Our results revealed that Cr(VI) induced apoptosis and inhibited proliferation in L02 hepatocytes via reactive oxygen species (ROS), the formation of which is closely related to mitochondrial damage, especially the inhibition of mitochondrial respiratory chain complex (MRCC). We also confirmed that ROS-mediated miR-21-5p inhibition participated in cell apoptosis and proliferative inhibition induced by Cr(VI). Furthermore, programmed cell death protein 4 (PDCD4), the up-regulation of which was related to ROS over-production, was predicted and verified as a target of miR-21-5p. Transcription factor PDCD4 silencing suppressed apoptosis and stimulated cell proliferation. In conclusion, from the perspective of epigenetics, the present study revealed that ROS-mediated miR-21-5p regulated the proliferation and apoptosis of Cr(VI)-exposed L02 hepatocytes via targeting PDCD4, which provided the new targets for molecular intervention and treatment of liver damage in Cr(VI)-exposed population.

miR-1245a promotes the proliferation and invasion of colon adenocarcinoma by targeting BRCA2

Background

Colon adenocarcinoma (CA) is the most common one with poor survival in colon cancer. This study aims to investigate the effect of miR-1245a on the process of CA cells and its target gene BRCA2.

Methods

The expression of CA tissues and cells were evaluated by q RT-PCR. Then we explore the association between expression of miR-1245a and prognosis in the CA patients from the TCGA database. CCK8 assays, colony formation assays were performed to explore the effect of miR-1245a in CA cell proliferation. The invasion ability of CA cells was evaluated by Transwell assays. Western blot was performed to assess the BRCA2 expression. Luciferase reporter assay was employed to scrutinize the relationship between miR-1245a and BRCA2. Finally, rescue experiments were performed through BRCA2 downregulation and miR-1245a inhibitors by using colony formation assay and Transwell invasion assay.

Results

miR-1245a is upregulated in CA cells and tissues. Additionally, the high expression of miR-1245a was related to poor survival. CCK8 assays, colony formation assays and Transwell assays showed that miR-1245a promotes the proliferation and invasion of CA cells. The luciferase reporter assay indicated that miR-1245a targeted BRCA2 and inhibited its expression. The rescue experiment further showed that miR-1245a could restore the effect of BRCA2 on CA.

Conclusions

miR-1245a promotes the proliferation and invasion of CA by targeting BRCA2.Our results suggested that miR-1245a could be a potential biomarker for CA progression.

Long noncoding RNA CHL1-AS1 promotes cell proliferation and migration by sponging miR-6076 to regulate CHL1 expression in endometrial cancer

Endometrial cancer (EC) is deemed to be the most typical gynecologic malignant tumor. Despite the incidence of EC being lower in Asia than that in western countries, substantial increased incidence has been observed in the past few decades in Asia. Although various molecular testing methods and genomic science have developed, the overall prognosis is still disappointing. LncRNAs have been found to influence the progression of various cancers. CHL1-AS1 has been found to be upregulated in ovarian endometriosis, nevertheless, the molecular mechanism and biological function of CHL1-AS1 in EC have not been explored. In our exploration, both CHL1-AS1 and CHL1 were upregulated in EC cells. Knockdown of CHL1-AS1 or CHL1 inhibited cell proliferation and migration in EC. Furthermore, microRNA-6076 (miR-6076) could bind with CHL1-AS1 or CHL1, and regulate the expression of CHL1. Finally, absence of miR-6076 or overexpression of CHL1 can partially rescue the effect of CHL1-AS1 knockdown or miR-6076 upregulation on cell proliferation and migration, respectively. All in all, our research was the first endeavor to study the underlying mechanism of CHL1-AS1 in EC and confirmed that CHL1-AS1 regulated EC progression via targeting the miR-6076/CHL1 axis, offering new insight into treating EC.

miR-4709 overexpression facilitates cancer proliferation and invasion via downregulating NR3C2 and is an unfavorable prognosis factor in colon adenocarcinoma

To date, microRNA-4709 (miR-4709) has not been studied in colon adenocarcinoma (COAD) on the basis of experiments. In our study, we aimed to investigate the biological roles and clinical significance of miR-4709 in COAD. The expression difference between miR-4709 and NR3C2 was measured based on The Cancer Genome Atlas database and cells. Kaplan-Meier and logrank tests were applied to determine the overall survival (OS) differences according to the miR-4709 and NR3C2 expression levels. To measure whether the miR-4709 level was associated with COAD cell growth, migration, and invasion, we respectively conducted 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound healing, and transwell assays. A luciferase reporter assay was applied to confirm the relationship between miR-4709 and its predicted target. High expression of miR-4709 was found in COAD tissues and cells. The OS rate in the miR-4709 low expression group was significantly higher than that in the miR-4709 high expression group. Univariate and multivariate analyses exhibited that miR-4709 expression was an independent adverse prognostic factor. Exogenous miR-4709 overexpression promoted proliferation, migration, and invasion of LOVO and SW480 cells. Bioinformatics analysis and luciferase assay demonstrated that miR-4709 directly binds to the 3'-untranslated region of NR3C2. NR3C2 was lowly expressed in COAD and high expression of NR3C2 had a better prognosis compared with that in the low expression of NR3C2. Correlation analysis showed that there is a close association between the level of expression of NR3C2 and miR-4709. Accordingly, miR-4709 may function as an oncogene in COAD and provide a preclinical proof for candidate management to target new miR-4709-NR3C2 signaling for COAD therapy.

Long Noncoding RNA GAS5 Acts As A Tumor Suppressor In Laryngeal Squamous Cell Carcinoma Via miR-21

Purpose

Long noncoding RNAs (lncRNAs) have been identified as an important class of noncoding RNAs that are deeply involved in multiple biological processes in tumorigenesis. This study is to investigate the critical roles and biological function of lncRNA growth arrest-specific 5 (GAS5) in tumorigenesis of laryngeal squamous cell carcinoma (LSCC).

Patients and methods

A total of 59 samples of LSCC and paired adjacent tissue, as well as corresponding clinicopathological information were collected. GAS5 expression in both LSCC tissues and human SUN1076 and SNU899 cell lines were analyzed by Real-time quantitative RT-PCR method. Ectopic expression of GAS5 by vector transfection in LSCC cell lines and followed by in vitro experiments was to investigate the critical roles and function of GAS5 in LSCC. Cell Counting Kit 8 (CCK8) assay and PE/7AAD Annexin V Apoptosis analysis was to evaluate cell proliferation ability and cell apoptosis. Co-transfection of GAS5 and miR-21 was to explore the interaction between GAS5 and miR-21 in LSCC. BAX and CDK6 protein level were analyzed by western blot method.

Results

This study demonstrated that GAS5 was significantly downregulated in LSCC tissue and human LSCC cell lines. GAS5 levels were correlated with the clinicopathological features of LSCC patients. In addition, the ectopic expression of GAS5 significantly inhibited cell proliferation and promoted apoptosis. Co-expression analyses indicated that GAS5 is negatively correlated with miR-21 in LSCC tissues. Overexpression of miR-21 eliminated GAS5-mediated cell apoptosis and proliferation suppression. Furthermore, GAS5, which upregulated BAX mRNA expression and downregulated CDK6 mRNA expression, was reversed by ectopic expression of miR-21.

Conclusion

GAS5 suppresses LSCC progression through the negative regulation of miR-21 and its targets involved in cell proliferation and apoptosis, indicating that GAS5 may serve as a biomarker and potential target for LSCC therapy.

Protein expression of close homologue of L1 (CHL1) is a marker for overall survival in non-small cell lung cancer (NSCLC)

BACKGROUND

The cell adhesion molecule close homologue of L1 (CHL1) is a potential tumour suppressor and was recently detected in non-small cell lung cancer (NSCLC) specimens. The expression pattern, prognostic, and functional role of CHL1 in NSCLCs is unknown.

METHODS

We evaluated the protein expression of CHL1 by immunohistochemistry in 2161 NSCLC patients based on a tissue microarray. The results were correlated with clinical, histopathological, and patient survival data (Chi square test, t test, and log-rank test, respectively). A multivariate analysis (Cox regression) was performed to validate its impact on patients' survival.

RESULTS

CHL1 was expressed in NSCLC patients and was significantly overexpressed in lung adenocarcinomas and squamous cell carcinomas compared to neuroendocrine and large cell carcinomas of the lung (p < 0.001). CHL1 expression was associated with the T stage in adenocarcinomas (p = 0.011) and with metastatic lymph node status and UICC stage in squamous cell carcinomas (p = 0.034 and p = 0.035, respectively). Increased CHL1 expression was associated with improved survival in univariate (p = 0.031) and multivariate analyses (odds ratio 0.797, 95% confidence interval 0.677-0.939, p = 0.007).

CONCLUSION

The prognostic significance of CHL1 makes it a potential prognostic and therapeutic target and underlines its role as a tumour suppressor. Further validation studies and functional analyses are needed to investigate its potential role in tumourigenesis and dissemination.

miR-21-5p promotes lung adenocarcinoma progression partially through targeting SET/TAF-Iα

OBJECTIVE

Although SET(I2PP2A) and miRNAs are reported to play a pivotal role in lung cancer, the underlying mechanisms have remained obscure. To address this issue, we investigated how miRNAs and SET participate in the progression of lung cancer.

METHODS

miRNAs that target SET were predicted from multiple miRNA databases. Three human NSCLC cell lines and two normal lung cell lines were used to evaluate aberrant miRNA and SET expressions. A dual luciferase reporter assay system was employed to verify the interaction between miRNA and SET. Stable miRNA knockdown and SET overexpression in A549 cells were achieved through lentivirus transfection; the corresponding influences on lung cancer progression were also examined.

RESULTS

In this study, A549 was the sole cell line to lack SET/TAF-Iα expression, which was inversely correlated with the up-regulation of miR-21-5p. SET was subsequently revealed as the direct target site of miR-21-5p in A549 cells. The stable miR-21-5p knockdown and SET/TAF-Iα overexpression were shown to markedly enhance the expression of SET/TAF-Iα and to inhibit the migration, invasion, proliferation as well as the in vivo tumorigenicity of A549 cells.

CONCLUSION

We suggest that SET/TAF-Iα might be a tumor suppressing factor regulated by miR-21-5p in lung adenocarcinoma. This might provide a target for lung adenocarcinoma therapy.

Decreased expression of long noncoding RNA XLOC_013703 promotes cell growth via NF-κB pathway in multiple myeloma

Long noncoding RNAs (lncRNAs) are dysregulated in cancer and involved in oncogenic or tumor inhibitory processes. The aim of the study was to investigate the expression pattern of lncRNA XLOC_013703 in multiple myeloma (MM) and to evaluate its biological role and potential significance. We found that XLOC_013703 was significantly decreased in CD138 positive plasma cells and serum of MM patients compared to normal controls, and the decreased XLOC_013703 expression was correlated with β2-MG, serum-free light chain (s-FLC) and revised international staging system. RNA-fluorescence in situ hybridization results revealed that XLOC_013703 was distributed both in the nucleus and in the cytoplasm of MM cells including H929, RPMI8226, and U266. Overexpression of XLOC_013703 inhibited the proliferation of U266 cells and blocked the cell cycle in G1 stage, thus contributing to MM cell apoptosis. By contrast, knockdown of XLOC_013703 promoted the growth of H929 cells. Western blot analysis confirmed that the expression of p-IκBα and nuclear P65 was substantially increased in shRNA transfection groups compared to control groups, whereas overexpression of XLOC_013703 reduced these expressions. In conclusion, we confirmed that the decreased expression of a novel lncRNA, XLOC_013703, in MM. XLOC_013703 was involved in MM cell survival and proliferation via nuclear factor-κB pathway which represents a potential therapeutic target for MM. © 2019 IUBMB Life, 71(9):1240-1251, 2019.