LINC01433/miR-2116-3p/MYC Feedback Loop Promotes Cell Proliferation, Migration, and the Epithelial-Mesenchymal Transition in Breast Cancer

HOXA-AS2 enhances GBM cell malignancy by suppressing miR-2116-3p thereby upregulating SERPINA3

Background

Glioblastoma (GBM) is malignant, demanding more attention to the improvement of the diagnosis and therapy. LncRNAs have been implicated in the malignancy of GBM cells.

Methods

HOXA-AS2, miR-2116-3p and SERPINA3 expression levels in GBM tissues and cell lines were detected by qRT-PCR. Western blotting was performed to detect the protein levels of Bax and Bcl-2. Dual-luciferase reporter assay was for detection of relationship among these factors, together with RIP and RNA pull-down. CCK-8, EdU, wound healing and transwell assays were for detection of the role of HOXA-AS2, miR-2116-3p and SERPINA3 in cell viability, proliferation, migration and invasion in GBM, respectively.

Results

HOXA-AS2 and SERPINA3 showed higher level in GBM tissues and cell lines. Low level of HOXA-AS2 attenuated GBM cell growth in vitro. Moreover, the anti-tumor impact of silenced HOXA-AS2 was restored by miR-2116-3p inhibitor, but its tumor-promotional effect could be reversed by silenced SERPINA3.

Conclusion

HOXA-AS2 enhanced GBM cell malignancy through sponging miR-2116-3p and releasing SERPINA3, which might shed light on the diagnosis and therapy for GBM in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09462-y.

Role of lncRNA AGAP2-AS1 in Breast Cancer Cell Resistance to Apoptosis by the Regulation of MTA1 Promoter Activity

Introduction Breast cancer (BC) is a common malignant tumor affecting women across the world. LncRNAs are frequently implicated in the course of BC. The current study set out to determine the specific effect of lncRNA AGAP2-AS1 on BC cell resistance to apoptosis. Methods AGAP2-AS1 expression patterns in BC tissues and cells were evaluated. si-AGAP2-AS1 was transfected into MCF-7 cells, followed by the assessment of cell proliferation and apoptosis. In addition to detection of MTA1 expression patterns, the binding relation between AGAP2-AS1 and HuR was verified using RNA pull-down and RNA immunoprecipitation. Next, the regulation enrichment of AGAP2-AS1- and HuR to H3K27ac recruitment in the MTA1 promoter was analyzed. MCF-7 cell resistance to apoptosis was observed after the combined experiment of histone deacetylase inhibitor M344 and si-AGAP2-AS1. Lastly, xenografts tumors were established to detect tumor weight and volume, tumor apoptosis and growth as well as expression of AGAP2-AS1 and MTA1. Results AGAP2-AS1 was overexpressed in BC tissues and cells, and AGAP2-AS1 silencing inhibited cell proliferation but facilitated apoptosis. Physiologically, AGAP2-AS1 bound to HuR to stabilize its own expression, and AGAP2-AS1-HuR complex upregulated H3K27ac levels in the MTA1 promoter region to elevate MTA1 promoter activity and MTA1 expression. H3K27ac upregulation partially-annulled the promotive effect of si-AGAP2-AS1 on BC apoptosis by upregulating MTA1. si-AGAP2-AS1 in vivo inhibited MTA1 expression to enhance apoptosis and suppress tumor growth. Conclusion Collectively, our findings indicated that AGAP2-AS1 bound to HuR to stabilize its own expression, and AGAP2-AS1-HuR complex enhanced H3K27ac levels in the MTA1 promoter region to improve MTA1 promoter activity and MTA1 expression in BC cells, so as to augment BC cell resistance to apoptosis.

Identification and functional analysis of a three-miRNA ceRNA network in hypertrophic scars

Background

Hypertrophic scar (HTS) is a fibrotic disorder of skins and may have repercussions on the appearance as well as functions of patients. Recent studies related have shown that competitive endogenous RNA (ceRNA) networks centering around miRNAs may play an influential role in HTS formation. This study aimed to construct and validate a three-miRNA (miR-422a, miR-2116-3p, and miR-3187-3p) ceRNA network, and explore its potential functions.

Methods

Quantitative real‑time PCR (qRT‑PCR) was used to compare expression levels of miRNAs, lncRNAs, and genes between HTS and normal skin. Target lncRNAs and genes of each miRNA were predicted using starBase as well as TargetScan database to construct a distinct ceRNA network; overlapping target lncRNAs and genes of the three miRNAs were utilized to develop a three-miRNA ceRNA network. For every network, protein–protein interaction (PPI) network analysis was performed to identify its hub genes. For each network and its hub genes, Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted to explore their possible functions.

Results

MiR-422a, miR-2116-3p, and miR-3187-3p were all downregulated in HTS tissues and fibroblasts. MiR-422a-based ceRNA network consisted of 101 lncRNAs with 133 genes; miR-2116-3p-centered ceRNA network comprised 85 lncRNAs and 978 genes; miR-3187-3p-derived ceRNA network encompassed 84 lncRNAs as well as 1128 genes. The three-miRNA ceRNA network included 2 lncRNAs with 9 genes, where MAPK1, FOSL2, ABI2, KPNA6, CBL, lncRNA-KCNQ1OT1, and lncRNA-EBLN3P were upregulated. According to GO and KEGG analysis, these networks were consistently related to ubiquitination. Three ubiquitination-related genes (CBL, SMURF2, and USP4) were upregulated and negatively correlated with the expression levels of the three miRNAs in HTS tissues.

Conclusions

This study identified a three-miRNA ceRNA network, which might take part in HTS formation and correlate with ubiquitination.

CRISPR/Cas9 uPAR Gene Knockout Results in Tumor Growth Inhibition, EGFR Downregulation and Induction of Stemness Markers in Melanoma and Colon Carcinoma Cell Lines

uPAR is a globular protein, tethered to the cell membrane by a GPI-anchor involved in several cancer-related properties and its overexpression commonly correlates with poor prognosis and metastasis. We investigated the consequences of uPAR irreversible loss in human melanoma and colon cancer cell lines, knocking out its expression by CRISPR/Cas9. We analyzed through flow cytometry, western blotting and qPCR, the modulation of the most known cancer stem cells-associated genes and the EGFR while we observed the proliferation rate exploiting 2D and 3D cellular models. We also generated uPAR “rescue” expression cell lines as well as we promoted the expression of only its 3’UTR to demonstrate the involvement of uPAR mRNA in tumor progression. Knocking out PLAUR, uPAR-encoding gene, we observed an inhibited growth ratio unexpectedly coupled with a significant percentage of cells acquiring a stem-like phenotype. In vivo experiments demonstrated that uPAR loss completely abrogates tumorigenesis despite the gained stem-like profile. Nonetheless, we proved that the reintroduction of the 3’UTR of PLAUR gene was sufficient to restore the wild-type status validating the hypothesis that such a region may act as a “molecular sponge”. In particular miR146a, by binding PLAUR 3’ UTR region might be responsible for uPAR-dependent inhibition of EGFR expression.

LINC01433 targets miR-506-3p to promote the biological progress of nasopharyngeal carcinoma cells

PURPOSE

The current study aimed to investigate the role of long intergenic noncoding 01433 (LINC01433) in the proliferation, migration and invasion of nasopharyngeal carcinoma (NPC).

METHODS

Real-time quantitative PCR (RT-qPCR) was performed to determine the expressions of LINC01433 and miR-506-3p in NPC samples and cell lines. The effects of LINC01433 on cell proliferation, migration and invasion were measured by CCK-8, wound healing assay and Transwell, respectively. In addition, Pearson correlation analysis, starBase, RNA immunoprecipitation, luciferase assay, Western blot and functional experiments were conducted to detect and confirm the relationship between LINC01433 and miR-506-3p.

RESULTS

LINC01433 level was noticeably elevated in NPC tissues and cell lines. As the expression of LINC01433 in 5-8F cells was the highest in NPC cell lines and the expression of LINC01433 in SUNE1 cells was the lowest, 5-8F and SUNE1 cells were therefore selected as the target cells for following experiments. Furthermore, miR-506-3p was predicted as the target of LINC01433, and the two were negatively correlated with each other. Interestingly, overexpression of LINC01433 promoted proliferation, migration and invasion of NPC cells, while miR-506-3p reversed such effects of LINC01433. Moreover, LINC01433 silencing had the opposite effects to LINC01433 overexpression. Furthermore, miR-506-3p overexpression inhibited the expressions of MMP2, N-cadherin, p-PI3K and p-Akt, and promoted the expressions of E-cadherin and TIMP-2, and partially reversed the role of LINC01433 in promoting cancer development.

CONCLUSION

The current findings reveal that LINC01433 regulates NPC cell biological progress through miR-506-3p.

Long non-coding RNA FALEC promotes colorectal cancer progression via regulating miR-2116-3p-targeted PIWIL1

BACKGROUND

Colorectal cancer (CRC) is one of the most common digestive malignant tumors globally. Focally amplified lncRNA on chromosome 1 (FALEC) is a novel lncRNA that has been reported to be involved in many biological processes during carcinogenesis. However, its role in CRC remains poorly understood.

METHODS

Gene expression at mRNA or protein level was measured by qRT-PCR or western blot, respectively. In vitro experiments including EdU, colony formation, flow cytometry, wound-healing and transwell assays, as well as in vivo xenograft experiment, were utilized to determine the functional role of FALEC in CRC. Relevant mechanical assays were performed to investigate the underlying molecular mechanism.

RESULTS

FALEC was aberrantly up-regulated in CRC. FALEC knockdown could impair CRC cell proliferation, migration and invasion, whereas facilitate cell apoptosis. MiR-2116-3p was revealed to be sponged by FALEC. PIWIL1 was identified as the target of miR-2116-3p. Mechanically, FALEC restored the expression of PIWIL1 via absorbing miR-2116-3p. MiR-2116-3p inhibition and PIWIL1 enrichment could counteract the anti-tumor impact induced by silenced FALEC on the oncogenic behaviors of CRC cells.

CONCLUSION

Our study revealed that FALEC promoted CRC progression via restoring the expression of miR-2116-3p-targeted PIWIL1, suggesting the potential application of targeting FALEC in the treatment of CRC.

MYC as a Multifaceted Regulator of Tumor Microenvironment Leading to Metastasis

The Myc family of oncogenes is deregulated in many types of cancer, and their over-expression is often correlated with poor prognosis. The Myc family members are transcription factors that can coordinate the expression of thousands of genes. Among them, c-Myc (MYC) is the gene most strongly associated with cancer, and it is the focus of this review. It regulates the expression of genes involved in cell proliferation, growth, differentiation, self-renewal, survival, metabolism, protein synthesis, and apoptosis. More recently, novel studies have shown that MYC plays a role not only in tumor initiation and growth but also has a broader spectrum of functions in tumor progression. MYC contributes to angiogenesis, immune evasion, invasion, and migration, which all lead to distant metastasis. Moreover, MYC is able to promote tumor growth and aggressiveness by recruiting stromal and tumor-infiltrating cells. In this review, we will dissect all of these novel functions and their involvement in the crosstalk between tumor and host, which have demonstrated that MYC is undoubtedly the master regulator of the tumor microenvironment. In sum, a better understanding of MYC’s role in the tumor microenvironment and metastasis development is crucial in proposing novel and effective cancer treatment strategies.

By targeting TRAF6, miR-140-3p inhibits TGF-β1-induced human osteosarcoma epithelial-to-mesenchymal transition, migration, and invasion

OBJECTIVES

We evaluated the effects of miR-140-3p on EMT, cellular migration, and invasion in TGF-β1 treated human OS cells. Human fresh OS tissue and normal bone tissue specimens were gathered from 42 patients (29 male and 13 female, 11 to 24 years of age with a mean age of 17.5 ± 2.3 years) diagnosed with OS by pathology. By targeting TRAF6, miR-140-3p inhibits TGF-β1-induced human osteosarcoma epithelial-to-mesenchymal transition, migration, and invasion.

RESULTS

In this study, we found microRNA (miR)-140-3p to be down-regulated and tumor necrosis factor receptor-associated factor 6 (TRAF6) to be up-regulated in patient OS samples. Lower levels of miR-140-3p and higher levels of TRAF6 were found in the advanced Enneking stage of OS. Furthermore, both mRNA and protein levels of TRAF6 were negatively associated with miR-140-3p mRNA expression in human OS tissue. TRAF6 was verified as a direct target of miR-140-3p in TGF-β1-treated human U2OS cells. Further, a miR-140-3p mimic dramatically inhibited while a miR-140-3p inhibitor enhanced TGF-β1-induced epithelial-to-mesenchymal transition, migration, and invasion of U2OS cells. Small interfering RNA was found to silence TRAF6 and to partly reverse the effects of the miR-140-3p inhibitor on TGF-β1-treated U2OS cells in vitro.

CONCLUSION

These results demonstrate miR-140-3p to function as a tumor inhibitor of human OS cells by decreasing TRAF6 expression. miR-140-3p and TRAF6 may be valuable and novel biomarkers for diagnosis and treatment of OS.

A Feedback Loop Regulation Of LINC01433 And YAP Promotes Malignant Behavior In Gastric Cancer Cells

Background

Gastric cancer (GC) is one of the most common cancers and the second leading cause of cancer-related death worldwide. Long noncoding RNAs (lncRNAs) are associated with GC development and progression. However, the functional roles and underlying mechanism of LINC01433 on GC progression remain elusive.

Methods

Firstly, the expression of LINC01433 was examined in 76 pairs of primary GC and corresponding adjacent non-tumorous tissues. Next, overexpression and knockdown experiments were conducted in GC cells to explore the effect of LINC01433 on the malignant behaviors of GC cells. Then, the interaction between LINC01433 and YAP was detected by RNA immunoprecipitation (RIP) and RNA pull-down assays.

Results

We found that LINC01433 was significantly upregulated in GC tissues and cell lines and correlated with poor prognosis. Through gain- and loss-of-function experiments, we demonstrated that LINC01433 promoted proliferation, migration, invasion and chemotherapy resistance in GC cells. Further mechanistic investigation revealed that LINC01433 could stabilize oncoprotein YAP through enhancing the interaction between deubiquitinase USP9X and YAP. LINC01433 decreased the phosphorylation of YAP via suppressing YAP-LATS1 association. Intriguingly, YAP directly bound to LINC01433 promoter region and activated its transcription. Thus, LINC01433 and YAP formed a positive feedback loop.

Conclusion

Collectively, our study demonstrates that the positive feedback loop between LINC01433 and YAP promotes GC progression, and implies that the LINC01433-YAP feedback loop may be a promising therapeutic target for GC treatment.