Miz-1 promotes the proliferation of esophageal cancer cells via suppression of p21 and release of p21-arrested cyclin D1

hsa-miR-195-5p inhibits cell proliferation of human thyroid carcinoma cells via modulation of p21/cyclin D1 axis

Background

Based on existing evidence, microRNAs (miRs) are gene regulators that undertake key functions in the oncogenesis and tumor progression of every single human malignant disease, such as thyroid carcinoma (TC). Previous clinical findings showed that expression of miR-195 is down-regulated in TC, which implies that miR-195 may be practically involved in TC pathogenesis. Nevertheless, the function of hsa-miR-195-5p in TC is still largely unclear. Herein, we detected the conceivable involvement of hsa-miR-195-5p in TC cell proliferation.

Methods

Real time PCR examination was performed to assess the expression level of hsa-miR-195-5p in TC cell lines TPC-1 and B-CPAP. TPC-1 cells were transfected with either hsa-miR-195-5p mimics or hsa-miR-195-5p inhibitor. After confirmation of transfection efficiency, the effect of hsa-miR-195-5p on proliferation and cell cycle of TPC-1 cells was assessed. The expression of cyclin D1 and p21 was simultaneously detected by western blotting. Moreover, targetScan 6.2 was used to predict hsa-miR-195-5p target genes. Subsequently, luciferase reporter was performed to examine whether there is a possible binding of hsa-miR-195-5p to 3’-UTR of cyclin D1 mRNA. Furthermore, cyclin D1 mRNA and protein levels were measured to check whether hsa-miR-195-5p exerts its function at the post-transcriptional level. In addition, to explore the function of cyclin D1 in TPC-1 cells overexpressing hsa-miR-195-5p, cyclin D1 siRNA was used to silence the expression of cyclin D1 in TPC-1 cells overexpressing hsa-miR-195-5p.

Results

We quantified the expression of hsa-miR-195-5p in TC cells and normal thyroid cells and found a remarkable decrease in hsa-miR-195-5p expression in TC cells. Over-expression of hsa-miR-195-5p obviously resulted in downgraded proliferation of TC cells. Moreover, hsa-miR-195-5p caused cell arrest at the GO/G1 phase. Further in silico analyses and the dual-luciferase reporter assay confirmed that 3’-UTR of cyclin D1 is a direct target of hsa-miR-195-5p. Western blot analysis uncovered that hsa-miR-195-5p over-expression led to decreased levels of cyclin D1 and p21. In mechanistic analyses, we found that silencing of cyclin D1 reversed the inhibitory effect of hsa-miR-195-5p on the proliferation of TC cells, which indicates that hsa-miR-195-5p suppresses TC cell proliferation by adversely regulating cyclin D1.

Conclusions

We concluded that hsa-miR-195-5p is a candidate tumor-suppressor miRNA in TC and that the hsa-miR-195-5p/p21/cyclin D1 pathway could be a potential therapeutic target for TC.

SNX16 activates c-Myc signaling by inhibiting ubiquitin-mediated proteasomal degradation of eEF1A2 in colorectal cancer development

Sorting nexin 16 (SNX16), a member of the sorting nexin family, has been implicated in tumor development. However, the function of SNX16 has not yet been investigated in colorectal cancer (CRC). Here, we showed that SNX16 expression was significantly upregulated in CRC tissues compared with normal counterparts. Upregulated mRNA levels of SNX16 predicted poor survival of CRC patients. Functional experiments showed that SNX16 could promote CRC cells growth both in vitro and in vivo. Knockdown of SNX16 induced cell cycle arrest and apoptosis, whereas ectopic overexpression of SNX16 had the opposite effects. Mechanistically, SNX16‐eukaryotic translation elongation factor 1A2 (eEF1A2) interaction could inhibit the degradation and ubiquitination of eEF1A2, followed by activation of downstream c‐Myc signaling. Our study unveiled that the SNX16/eEF1A2/c‐Myc signaling axis could promote colorectal tumorigenesis and SNX16 might potentially serve as a novel biomarker for the diagnosis and an intervention of CRC.

Identification of key genes and pathways for esophageal squamous cell carcinoma by bioinformatics analysis

The aim of the present study was to identify the differentially expressed genes (DEGs) in esophageal squamous-cellcarcinoma (ESCC) and provide potential therapeutic targets. The microarray dataset GSE20347 was downloaded from the Gene Expression Omnibus (GEO) database, and included 17 tissue samples and 13 normal adjacent tissue samples from patients with ESCC. A total of 22,277 DEGs were identified. A heat map for the DEGs was constructed with the Morpheus online tool and the top 200 genes (100 upregulated and 100 downregulated) were selected for further bioinformatics analysis, including analysis of gene ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, protein-protein interaction networks and Spearman's correlation tests. The results of the GO analysis indicated that the upregulated DEGs were most significantly enriched in membrane-bounded vesicles in the cellular component (CC) category, but were not significantly enriched in any GO terms of the categories biological process (BP) or molecular function (MF); furthermore, the downregulated DEGs were most significantly enriched in regulation of DNA metabolic processes, nucleotide binding and chromosomes in the categories BP, MF and CC, respectively. The KEGG analysis indicated that the downregulated DEGs were enriched in the regulation of cell cycle pathways. The top 10 hub proteins in the protein-protein interaction network were cyclin-dependent kinase 4, budding uninhibited by benzimidazoles 1, cyclin B2, heat shock protein 90AA1, aurora kinase A, H2A histone family member Z, replication factor C subunit 4, and minichromosome maintenance complex component 2, −4 and −7. These proteins are mainly involved in regulating tumor progression. The genes in the four top modules were mainly implicated in regulating cell cycle pathways. Secreted Ly-6/uPAR-related protein (SLURP) was the hub gene, and SLURP and its interacting genes were most enriched in the chromosomal part in the CC category, organelle organization in the BP category and protein binding in the MF category, and were involved in pathways including DNA replication, cell cycle and P53 signaling. The expression of SLURP-1 in fifteen patients with esophageal carcinoma was detected using quantitative polymerase chain reaction analysis, and the results indicated that SLURP-1 expression was significantly decreased in the tumor samples relative to that in normal adjacent tissues. These results suggest that several hub proteins and the hub gene SLURP-1 may serve as potential therapeutic targets, and that gene dysfunction may be involved in the tumorigenesis of ESCC.

RLIM suppresses hepatocellular carcinogenesis by up-regulating p15 and p21

Hepatocellular carcinogenesis results from dysregulation of oncogenes and tumor suppressors that influence cellular proliferation, differentiation and apoptosis. p15 and p21 are cyclin-dependent kinase inhibitors, which arrest cell proliferation and serve as critical tumor suppressors. Here we report that the E3 ubiquitin ligase RLIM expression is downregulated in hepatocellular carcinoma patients, and correlated with p15 and p21 expression in clinical progression. In addition, we showed that RLIM overexpression suppresses the cell growth and arrests cell cycle progression of hepatocellular carcinoma. Mechanistically, we found that RLIM directly binds to MIZ1, disrupting the interaction between c-MYC and MIZ1, and enhancing p15 and p21 transcription. Our results demonstrate that RLIM is an important suppressor in hepatocellular carcinogenesis.

Investigating the potential of Oxymatrine as a psoriasis therapy

Psoriasis vulgaris is a chronic inflammatory skin disease, stubbornly intractable, with substantial consequences for patient physical and mental welfare. Approaches currently available to treat psoriasis are not satisfactory due to undesirable side-effects or expense. Psoriasis is characterized by hyperproliferation and inflammation. Oxymatrine, an active component extracted from Sophora flavescens, has been demonstrated to possess anti-proliferation, anti-inflammatory, anti-tumorigenic, immune regulation and pro-apoptotic properties. This investigation presents a detailed retrospective review examining the effect of Oxymatrine on psoriasis and investigates the mechanisms underlying patient responses to Oxymatrine. We confirm that Oxymatrine administration significantly reduced the Psoriasis Area Severity Index score, with high efficacy compared to the control group. In addition, we have found that Oxymatrine significantly inhibits the viability, proliferation and differentiation of human keratinocyte in vitro. Immunohistochemical analysis indicates Oxymatrine significantly suppresses the expression of Pan-Cytokeratin, p63 and keratin 10. The results indicate that the suppression of p63 expression may lead to the anti-proliferation effect of Oxymatrine on human skin keratinocytes. Oxymatrine does not affect the formation of basement membrane, which is very important to maintain the normal function of human skin keratinocytes. In summary, Oxymatrine offers an effective, economical, and safe treatment for patients presenting with intractable psoriasis vulgaris.

Downregulation of TNFAIP2 suppresses proliferation and metastasis in esophageal squamous cell carcinoma through activation of the Wnt/β-catenin signaling pathway

Tumor necrosis factor-α (TNF-α) plays a pivotal role in malignant tumor formation in the tumor microenvironment. To investigate the role of TNF-α in esophageal squamous cell carcinoma (ESCC), we assessed expression profiles of the downstream gene TNF-α-induced protein 2 (TNFAIP2), which e previously unknown in ESCC. TNFAIP2 mRNA and protein expression levels were examined by qRT-PCR and immunohistochemical analysis in 24 fresh and 55 paraffin‑embedded specimens, respectively. The results demonstrated that TNFAIP2 mRNA and protein levels were overexpressed in tumor cells, and TNFAIP2 overexpression was significantly associated with T stage (p=0.049), N stage (p=0.019) and the International Union Against Cancer (UICC) stage (p=0.028). In vitro, TNFAIP2 was highly expressed in TNFα-stimulated Eca109, Kyse150, Kyse510 and TE-10 cells. Lentivirus-mediated RNA interference of TNFAIP2 inhibited cell proliferation, colony formation, migration, invasion and the cell cycle. Moreover, LV-RNAi-mediated TNFAIP2 was found to regulate the Wnt/β-catenin by decreasing expression of some genes downstream from β-catenin (i.e., C-myc, cyclin D1, MMP-7 and Snail), and upregulating expression of E-cadherin and p-GSK-3β. Taken together, these results show that TNFAIP2 may be a potential tumorigenesis gene in ESCC. Our data indicate that TNFAIP2 overexpression may facilitate proliferation and metastasis via activation of the Wnt/β-catenin signaling pathway in ESCC.

MicroRNA-92a Promotes Cell Proliferation in Cervical Cancer via Inhibiting p21 Expression and Promoting Cell Cycle Progression

MicroRNA-92a (miR-92a) generally plays a promoting role in human cancers, but the underlying mechanism in cervical cancer remains unclear. Here we studied the expression and clinical significance of miR-92a in cervical cancer, as well as the regulatory mechanism in the proliferation of cervical cancer cells. Our data indicated that miR-92a was significantly upregulated in cervical cancer tissues compared to their matched adjacent nontumor tissues (ANTs), and the increased miR-92a levels were significantly associated with a higher grade, lymph node metastasis, and advanced clinical stage in cervical cancer. In vitro study revealed that inhibition of miR-92a led to a significant reduction in the proliferation of HeLa cells via induction of cell cycle arrest at the G₁ stage. In contrast, overexpression of miR-92a markedly promoted the proliferation of HeLa cells by promoting cell cycle progression. Further investigation revealed that miR-92a has a negative effect on protein levels, but not the mRNA levels, of p21 in HeLa cells, suggesting that p21 is a direct target of miR-92a. Overexpression of p21 eliminated the promoting effects of miR-92a on the proliferation and cell cycle progression of HeLa cells. However, knockdown of p21 reversed the suppressive effects of miR-92a downregulation on HeLa cell proliferation and cell cycle progression. Moreover, p21 was significantly downregulated in cervical cancer tissues compared to ANTs, suggesting that the increased expression of miR-92a may contribute to the decreased expression of p21, which further promotes cervical cancer growth. In conclusion, our study demonstrates that miR-92a promotes the proliferation of cervical cancer cells via inhibiting p21 expression and promoting cell cycle progression, highlighting the clinical significance of miR-92a in cervical cancer.