miR-892a regulated PPP2R2A expression and promoted cell proliferation of human colorectal cancer cells

PPP2R2A inhibition contributes to preeclampsia by regulating the proliferation, apoptosis, and angiogenesis modulation potential of mesenchymal stem cells

BACKGROUND

The precise mechanisms underlying preeclampsia (PE) pathogenesis remain unclear. Mesenchymal stem cells (MSCs) are involved in the pathology of PE. The aim of our study was to identify the effects of protein phosphatase 2 regulatory subunit B α (PPP2R2A) on MSCs and ascertain its latent role in the progression of PE.

METHODS

Reverse-transcription quantitative polymerase chain reaction and western blot analyses were performed to determine the expression of PPP2R2A in decidual tissue and decidual (d)MSCs from healthy pregnant women and patients with PE as well as the expression levels of Bax and Bcl-2 in dMSCs. The levels of p-PI3K, PI3K, p-AKT, and AKT were determined using western blotting. Cell growth, apoptosis, and migration were analyzed using MTT, flow cytometry, and Transwell assays, respectively. Human umbilical vein endothelial cell (HUVEC) tube formation ability was assayed using a HUVEC capillary-like tube formation assay.

RESULTS

PPP2R2A was downregulated in decidual tissues and dMSCs of patients with PE when compared with that in healthy pregnant women. Moreover, upregulation of PPP2R2A enhanced cell proliferation, reduced apoptotic dMSC, inhibited Bax expression, and increased Bcl-2 levels. Conditioned medium from PPP2R2A-overexpressing dMSCs promoted HTR-8/SVneo cell migration and angiogenesis of HUVEC. Furthermore, the PPP2R2A plasmid suppressed PI3K/AKT pathway activation in dMSCs. However, these effects were partially reversed by LY2940002 treatment.

CONCLUSION

PPP2R2A inhibition contributes to PE by regulating the proliferation, apoptosis, and angiogenesis of MSCs, providing a new therapeutic target for PE diagnosis and treatment.

The role of miR-222-2p in exosomes secreted by hexavalent chromium-induced premature senescent hepatocytes as a SASP component

With the development of world industrialization, the environmental pollution of hexavalent chromium [Cr(VI)] is becoming an increasingly serious problem. In particular, the mechanisms by which long-term and low-dose exposure to Cr(VI) leading the development of related cancers are not well understood. As senescent cells gradually lose their ability to proliferate and divide, they will not be malignantly transformed. However, Senescence-associated secretory phenotype (SASP) released by senescent cells into the cellular microenvironment can act on neighboring cells. Since SASP has a bidirectional regulatory role in the malignant transformation of cells. Hence, It is very necessary to identified the composition and function of SASP which secreted by Cr(VI) induced senescent L02 hepatocytes (S-L02). Exosomes, a vesicle-like substances released extracellularly after the fusion of intracellular multivesicular bodies with cell membrane, are important components of SASP and contain a large number of microRNAs (miRNAs). By establishing Cr(VI)-induced S-L02 model, we collected the exosomes from the supernatants of S-L02 and L02 culture medium respectively, and screened out the highly expressed miRNAs in the exosomes of S-L02, namely the new SASP components. Among them, the increase of miR-222-5p was the most significant. It was validated that as SASP, miR-222-5p can inhibit the proliferation of L02 and S-L02 hepatocytes and at the same time accelerate the proliferation and migration ability of HCC cells. Further mechanistic studies revealed that miR-222-5p attenuated the regulatory effect of protein phosphatase 2A subunit B isoform R2-α (PPP2R2A) on Akt via repressing its target gene PPP2R2A, causing reduced expressions of forkhead box O3 (FOXO3a), p27 and p21, and finally increasing the proliferation of HCC cells after diminishing the negative regulation of on cell cycle. This study certainly provides valuable laboratory evidence as well as potential therapeutic targets for the prevention and further personalized treatment of Cr(VI)-associated cancers.

Nanostructured Silicon Enabled HR-MS for the Label-Free Detection of Biomarkers in Colorectal Cancer Plasma Small Extracellular Vesicles

Despite improvements in treatment options for advanced colorectal cancer (CRC), survival outcomes are still best for patients with non-metastasised disease. Diagnostic tools to identify blood-based biomarkers and assist in CRC subtype classification could afford a means to track CRC progression and treatment response. Cancer cell-derived small extracellular vesicles (EVs) circulating in blood carry an elevated cargo of lipids and proteins that could be used as a signature of tumour suppressor/promoting events or stages leading up to and including metastasis. Here, we used pre-characterised biobanked plasma samples from surgical units, typically with a low volume (~100 µL), to generate and discover signatures of CRC-derived EVs. We employed nanostructured porous silicon (pSi) surface assisted-laser desorption/ionisation (SALDI) coupled with high-resolution mass spectrometry (HR-MS), to allow sensitive detection of low abundant analytes in plasma EVs. When applied to CRC samples, SALDI-HR-MS enabled the detection of the peptide mass fingerprint of cancer suppressor proteins, including serine/threonine phosphatases and activating-transcription factor 3. SALDI-HR-MS also allowed the detection of a spectrum of glycerophospholipids and sphingolipid signatures in metastatic CRC. We observed that lithium chloride enhanced detection sensitivity to elucidate the structure of low abundant lipids in plasma EVs. pSi SALDI can be used as an effective system for label-free and high throughput analysis of low-volume patient samples, allowing rapid and sensitive analysis for CRC classification.

The circular RNA circTXNRD1 promoted ambient particulate matter-induced inflammation in human bronchial epithelial cells by regulating miR-892a/COX-2 axis

Particulate matter (PM)-induced airway inflammation contributes to the development and exacerbation of chronic airway diseases. Circular RNA (circRNA) is a new class of non-coding RNA that participates in gene regulation in various respiratory diseases, but the regulatory role of circRNA in PM-induced airway inflammation has not been fully elucidated. In this study, we performed the human circRNA microarray to reveal differentially expressed circRNAs in PM-induced human bronchial epithelial cells (HBECs). A total of 176 upregulated and 15 downregulated circRNAs were identified. Of these, a new circRNA termed circTXNRD1 was upregulated by PM exposure in a dose- and time-dependent manner. Knockdown of circTXNRD1 significantly attenuated PM-induced expression of proinflammatory cytokine interleukin 6 (IL-6). CircRNA pull-down, dual-luciferase reporter assay and fluorescence in situ hybridization showed that circTXNRD1 acted as an endogenous sponge to decrease miR-892a levels in HBECs. Downregulation of miR-892a could increase cyclooxygenase-2 (COX-2) expression and eventually promote IL-6 secretion in PM-induced HBECs. Taken together, our findings reveal circTXNRD1 as a novel inflammatory mediator in PM-induced inflammation in HBECs via regulating miR-892a/COX-2 axis. These results provide new insight into the biological mechanism underlying PM-induced inflammation in chronic airway diseases.

PPP2R2A affects embryonic implantation by regulating the proliferation and apoptosis of Hu sheep endometrial stromal cells

Embryonic implantation is a complex reproductive physiological process in mammals. Although several endometrial proteins affecting embryonic implantation have been reported in the past, there are still potential endometrial proteins that have been neglected, and their specific regulatory mechanisms are unclear. This study demonstrated that protein phosphatase 2A regulatory subunit B55α (PPP2R2A) served as a novel regulator in medication of sheep embryonic implantation in vitro. Our results showed that sheep PPP2R2A encoded 447 amino acids and shared 91.74%-92.36% amino acid sequences with its orthologs compared with other species. Meanwhile, PPP2R2A was widely expressed in sheep uterine tissues, and it could regulate the expression levels of key regulators of embryonic implantation in endometrial stromal cells (ESCs). Knockdown of PPP2R2A significantly inhibited cell proliferation by blocking cell cycle transfer G0/G1 into S phase accompanied by downregulation of CDK2, CDK4, CCND1, CCNE1 and upregulation of P21. In contrast to PPP2R2A overexpression, PPP2R2A interference greatly promoted cell apoptosis and the expression of BAX, CASP3, CASP9 and BAX/BCL-2. Taken together, these results suggest that PPP2R2A, as a novel regulatory factor, affects embryonic implantation via regulating the proliferation and apoptosis of Hu sheep ESCs in vitro.

miR-660 promotes liver cancer cell proliferation by targeting PPP2R2A

Liver cancer (LC) is the leading cause for tumor-related death worldwide, and microRNAs (miRs) have been demonstrated to regulate the progression of LC. In the current study, the function of miR-660 in LC cells was investigated, and the results indicated that miR-660 was highly expressed in LC tissues and cells. This increased expression promoted LC cell proliferation and increased the percentage of S phase cells, while miR-660 knockdown inhibited cell proliferation and increased the percentage of G₀/G₁ phase cells. A Ser/Thr phosphatase protein phosphatase 2 regulatory subunit βα (PPP2R2A) was indicated as the target of miR-660, and miR-660 could inhibit PPP2R2A levels. The luciferase reporter assay suggested that miR-660 directly bound to the 3'-untranslated region of PPP2R2A. Additionally, it was revealed that miR-660 inhibited p21 expression and promoted cyclin D1 expression, confirming that miR-660 regulated LC cell proliferation by regulating cell cycle progression. The double knockdown of miR-660 and PPP2R2A promoted LC cell proliferation, suggesting that miR-660 promoted LC proliferation by targeting PPP2R2A.

ChrXq27.3 miRNA cluster functions in cancer development

MicroRNAs (miRNAs) regulate the expression of their target genes post-transcriptionally; thus, they are deeply involved in fundamental biological processes. miRNA clusters contain two or more miRNA-encoding genes, and these miRNAs are usually coexpressed due to common expression mechanisms. Therefore, miRNA clusters are effective modulators of biological pathways by the members coordinately regulating their multiple target genes, and an miRNA cluster located on the X chromosome q27.3 region has received much attention in cancer research recently. In this review, we discuss the novel findings of the chrXq27.3 miRNA cluster in various types of cancer.

The chrXq27.3 miRNA cluster contains 30 mature miRNAs synthesized from 22 miRNA-encoding genes in an ~ 1.3-Mb region. The expressions of these miRNAs are usually negligible in many normal tissues, with the male reproductive system being an exception. In cancer tissues, each miRNA is dysregulated, compared with in adjacent normal tissues. The miRNA-encoding genes are not uniformly distributed in the region, and they are further divided into two groups (the miR-506-514 and miR-888-892 groups) according to their location on the genome. Most of the miRNAs in the former group are tumor-suppressive miRNAs that are further downregulated in various cancers compared with normal tissues. miR-506-3p in particular is the most well-known miRNA in this cluster, and it has various tumor-suppressive functions associated with the epithelial–mesenchymal transition, proliferation, and drug resistance. Moreover, other miRNAs, such as miR-508-3p and miR-509-3p, have similar tumor-suppressive effects. Hence, the expression of these miRNAs is clinically favorable as prognostic factors in various cancers. However, the functions of the latter group are less understood. In the latter group, miR-888-5p displays oncogenic functions, whereas miR-892b is tumor suppressive. Therefore, the functions of the miR-888–892 group are considered to be cell type- or tissue-specific.

In conclusion, the chrXq27.3 miRNA cluster is a critical regulator of cancer progression, and the miRNAs themselves, their regulatory mechanisms, and their target genes might be promising therapeutic targets.

Prognostic value of miR-892a in gastric cancer and its regulatory effect on tumor progression

BACKGROUND

Gastric cancer is a prevalent malignant around the world. Aberrantly expression of microRNAs (miRNAs) contributes to the progression of tumors. The aim of this study was to investigate the expression and role of miR-892a in gastric cancer.

METHODS

A total of 119 gastric cancer patients were enrolled in this study. And the expression of miR-892a in gastric cancer tissues and cells was measured using RT-qPCR analysis. Kaplan-Meier plotter and multivariate Cox regression analysis were used to explore the prognostic value of miR-892a in gastric cancer. The biological function of miR-892a in gastric cancer cells was evaluated using CCK-8 assays and Transwell assays.

RESULTS

The expression of miR-892a was high-expressed in gastric cancer tissues and cells. The miR-892a expression was associated with tumor size, differentiation, lymph node metastasis, and TNM stages. Gastric cancer patients with high miR-892a expression showed a short overall survival rate. Overexpression of miR-892a promoted cell proliferation, migration, and invasion of gastric cancer cells.

CONCLUSION

miR-892a was upregulated and predictor of poor prognosis in gastric cancer patients. The miR-892a in gastric cancer cells significantly promoted cell proliferative, migratory, and invasive properties. Furthermore, miR-892a may be served as a prognostic marker as well as a therapeutic target for gastric cancer.

Hepsin Promotes Epithelial-Mesenchymal Transition and Cell Invasion Through the miR-222/PPP2R2A/AKT Axis in Prostate Cancer

Purpose

To determine the role and underlying mechanism of hepsin in epithelial–mesenchymal transition (EMT) and cell invasion in prostate cancer.

Methods

The expression of hepsin in prostate cancer tissue samples and cell lines was measured by immunohistochemical staining and Western blotting. The EMT and cell invasion abilities of prostate cancer cells were detected by Western blot and transwell assays. RNA transfection was used to inhibit or overexpress related genes. The expression of miR-222 was detected by RT-qPCR. A dual‑luciferase reporter gene assay was performed to determine the target of miR-222.

Results

Hepsin expression was upregulated in prostate cancer tissue samples and cell lines. Inhibition of hepsin attenuated EMT and cell invasion and downregulated the expression of miR-222. Decreased miR-222 expression enhanced the level of PPP2R2A, which in turn attenuated the AKT signaling. Activation of miR-222 or AKT could block the inhibitory effects on EMT and cell invasion induced by hepsin deficiency.

Conclusion

Hepsin promotes EMT and cell invasion through the miR-222/PPP2R2A/AKT axis in prostate cancer.

Hsa-MiR-590-3p Promotes the Malignancy Progression of Pancreatic Ductal Carcinoma by Inhibiting the Expression of p27 and PPP2R2A via G1/S Cell Cycle Pathway

Objective

To investigate the effect of miR-590-3p on the malignant biological behavior of pancreatic cancer, and to explore the target genes and pathways directly affected by miR-590-3p, to provide new therapeutic ideas and targets for the study of the diagnosis and treatment of pancreatic cancer.

Methods

We used qRT-PCR to measure miR-590-3p expression quantities. We used cell cycle, CCK-8, clonal formation to verify the change of proliferation capacity of PC cells. We used transwell assay to detect the migration and invasion of PC cells. We used the bioinformatics tool TargetScan (http://www.targetscan.org) to identify the possible target genes of miR-590-3p. Immunohistochemistry revealed the clinicopathological significance of PPP2R2A, p27 and miR-590-3p in the expression of pancreatic cancer. Western blot was used to detect the expression changes of PPP2R2A, p27 and G1/S cell cycle pathway-related proteins CDK2, cyclinE2 and p21 after transfection of mimics and inhibitors of miR-590-3p.

Results

According to our study, hsa-miR-590-3p expression was significantly higher in PC tissues than that in paired normal pancreas, which was associated with PC tumor size (P=0.042) and preoperative CA19-9 level (P=0.046) of PC patients. Its overexpression promoted PC cell proliferation, invasion and migration following with the p27 and PPP2R2A protein downregulation in Capan-2, PANC-1 and BxPC-3 cells, and vice versa. Bioinformatics analysis and dual-luciferase reporter assay further confirmed that p27 and PPP2R2A were direct target genes of miR-590-3p. The negative relationship of miR-590-3p with p27 and PPP2R2A was also observed in PC tissues.

Conclusion

MiR-590-3p promotes the proliferation, migration and invasion of pancreatic cancer cells. MiR-590-3p directly downregulated p27 and PPP2R2A and via the G1/S cell cycle pathway to promote the development of pancreatic cancer.

MicroRNA-3690 promotes cell proliferation and cell cycle progression by altering DKK3 expression in human thyroid cancer

An increasing amount of evidence has demonstrated the importance of microRNAs (miRNAs/miRs) in the tumorigenesis of malignant types of cancer, and data retrieved from The Cancer Genome Atlas database revealed that miR-3690 was upregulated in thyroid cancer (TC). The present study focused on the biological function and mechanism of miR-3690 in TC, demonstrating that miR-3690 expression was significantly elevated in TC cells and clinical tissues. Functional studies indicated that miR-3690 acted as an oncogene in TC by promoting cell proliferation, colony formation and cell cycle progression in association with the increased expression of cyclin E and c-myc. Mechanistically, prediction software indicated that Dickkopf-related protein 3 (DKK3) was a target of miR-3690, which was confirmed by the results of luciferase reporter assays and western blotting. DKK3 silencing abrogated the functions of miR-3690-in on TC cell proliferation. Collectively, the findings of the present study demonstrated that miR-3690 promoted TC cell proliferation and indicated miR-3690 as a potential biomarker and therapeutic target for TC.

MicroRNA-892a regulates laryngocarcinoma cell proliferation via Dicer

IMPACT STATEMENT

This work expanded the knowledge of the molecular mechanisms underlying LC progression by exploring the role of miR-892a in the viability of TU212 and M4E cells. The results showed that miR-892a, which exhibited elevated expression in LC cells and tissue specimens of patients with LC, exerted an inhibitory effect on Dicer expression, whereas silencing of miR-892a in TU212 and M4E cells hindered cell proliferation and growth and promoted apoptosis. Furthermore, miR-892a was demonstrated to directly target Dicer 3'-UTR and inhibit its expression. These findings demonstrated that miR-892a acted as an LC oncogene via its action on Dicer, which further confirmed that miR-892a can serve as a diagnostic indicator or promising agent for LC treatment.

MicroRNA-98-5p Inhibits Tumorigenesis of Hepatitis B Virus-Related Hepatocellular Carcinoma by Targeting NF-κB-Inducing Kinase

PURPOSE

MicroRNAs play key regulatory roles in the tumorigenesis of hepatitis B virus-related hepatocellular carcinoma (HBV-HCC). This study aimed to explore the regulatory effects of microRNA-98-5p (miR-98-5p) on the proliferation, migration, invasion, and apoptosis of HBV-HCC cells, as well as the underlying mechanisms involving nuclear factor-κB-inducing kinase (NIK).

MATERIALS AND METHODS

The expressions of miR-98-5p and NIK in HBV-HCC tissues and cells, and the level of HBV DNA in HBV-HCC cells were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration, invasion, and apoptosis of HBV-HCC cells were analyzed by cell counting kit-8, wound healing, transwell, and flow cytometry assay, respectively. The targeting relationship between miR-98-5p and NIK was predicted by StarBase3.0 and verified by dual-luciferase reporter assay. HBV-HCC xenograft tumor model was constructed in mice to observe the tumor growth in vivo.

RESULTS

The expression of miR-98-5p was declined in HBV-HCC tissues and cells. Overexpression of miR-98-5p markedly reduced the level of HBV DNA; inhibited the proliferation, migration, and invasion; and promoted the apoptosis of HBV-HCC cells. NIK was a target of miR-98-5p. Overexpression of miR-98-5p markedly decreased the protein expression of NIK in MHCC97H-HBV cells. NIK reversed the tumor-suppressing effect of miR-98-5p on HBV-HCC cells. Furthermore, overexpression of miR-98-5p significantly inhibited the xenograft tumor growth and decreased the expression of NIK in mice.

CONCLUSION

MiR-98-5p inhibits the secretion of HBV, proliferation, migration, and invasion of HBV-HCC cells by targeting NIK.

microRNA-665 is down-regulated in gastric cancer and inhibits proliferation, invasion, and EMT by targeting PPP2R2A

Recently, microRNA-665 (miR-665) has been reported to function as both tumour suppressor and oncogene in several cancer types, including gastric cancer, hepatocellular cancer, and lung cancer. However, the biological function of miR-665 and its precise mechanisms in gastric cancer (GC) have not been well clarified. The aim of this study was to study the roles of miR-665/PPP2R2A axis in GC. The levels of PPP2R2A and miR-665 were detected by quantitative PCR assay in GC tissues and cell lines. Moreover, the biological roles of miR-665 and PPP2R2A in GC cells were assessed by cell proliferation, invasion, and epithelial-mesenchymal transition (EMT). The mRNA and protein levels of PPP2R2A were determined by using quantitative PCR and Western blotting assays. Luciferase assays were used to confirm that PPP2R2A was one target of miR-665. In this study, the miR-665 level was dramatically reduced in GC tissues and cell lines, and the PPP2R2A expression was significantly enhanced. What is more, the PPP2R2A expression was negatively related to the miR-665 level in GC tissues. Furthermore, up-regulation of miR-665 obviously restrained GC cells proliferation, invasion, and EMT. We confirmed that miR-665 could directly target PPP2R2A by luciferase reporter assay. Besides, knockdown of PPP2R2A also could markedly inhibit the proliferation, invasion and EMT of GC cells. Finally, overexpression of miR-665 in GC cells partially reversed the promoted effects of PPP2R2A up-regulation. Overexpression of miR-665 restrained GC cells proliferation, invasion and EMT via regulation of PPP2R2A. SIGNIFICANCE OF THE STUDY:  miR-665 has been reported to function as oncogene or tumour suppressor in different cancers. However, the precise roles of miR-665 in GC have not been elucidated. Our study for the first time demonstrated that miR-665 level was significantly down-regulated in GC. Additionally, miR-665 overexpression inhibited cell growth, invasion, and EMT of GC. Moreover, our data suggested a significant negative correlation between miR-665 and PPP2R2A expression in GC. MiR-665 suppressed GC cell proliferation, invasion, and EMT by directly targeting PPP2R2A, which suggested important roles for miR-665/PPP2R2A axis in the GC pathogenesis and its potential application in cancer therapy.

Somatic Mutations in miRNA Genes in Lung Cancer-Potential Functional Consequences of Non-Coding Sequence Variants

A growing body of evidence indicates that miRNAs may either drive or suppress oncogenesis. However, little is known about somatic mutations in miRNA genes. To determine the frequency and potential consequences of miRNA gene mutations, we analyzed whole exome sequencing datasets of 569 lung adenocarcinoma (LUAD) and 597 lung squamous cell carcinoma (LUSC) samples generated in The Cancer Genome Atlas (TCGA) project. Altogether, we identified 1091 somatic sequence variants affecting 522 different miRNA genes and showed that half of all cancers had at least one such somatic variant/mutation. These sequence variants occurred in most crucial parts of miRNA precursors, including mature miRNA and seed sequences. Due to our findings, we hypothesize that seed mutations may affect miRNA:target interactions, drastically changing the pool of predicted targets. Mutations may also affect miRNA biogenesis by changing the structure of miRNA precursors, DROSHA and DICER cleavage sites, and regulatory sequence/structure motifs. We identified 10 significantly overmutated hotspot miRNA genes, including the miR-379 gene in LUAD enriched in mutations in the mature miRNA and regulatory sequences. The occurrence of mutations in the hotspot miRNA genes was also shown experimentally. We present a comprehensive analysis of somatic variants in miRNA genes and show that some of these genes are mutational hotspots, suggesting their potential role in cancer.

Interactions among lncRNAs, miRNAs and mRNA in colorectal cancer

Long non-coding RNAs (lncRNAs) are longer than 200 nts non-coding transcripts and have recently emerged as one of the largest and significantly diverse RNA families whereas microRNAs (miRNAs) are highly conserved short single-stranded ncRNAs (∼18-22 nucleotides). As families of small and long evolutionarily conserved ncRNAs, lncRNAs activate and repress genes via a variety of mechanisms at both transcriptional and translational levels, while miRNAs regulate protein-coding gene expression mainly through mRNA degradation or silencing, These ncRNAs have been proved to be involved in multiple biological functions, such as proliferation, differentiation, migration, angiogenesis and apoptosis. Today, while majority of studies have focused on defining the regulatory functions of lncRNAs and miRNAs, limited information have now available for the mutual regulations of lncRNAs, miRNAs and mRNA. Thus, the underlying molecular mechanisms, in particularly the interactions among lncRNAs, miRNAs and mRNA in development, growth, metastasis and therapeutic potential of cancer still remain obscure. Colorectal cancer (CRC) is known as the third most common and fourth leading cancer death worldwide. Increasing evidence showed the close correlations among aberrant expressions of lncRNAs, miRNAs and the occurrence, development of CRC. This review summarize the potential links among these RNAs in following three areas: 1, The biogenesis and roles of miRNAs in CRC; 2, The biogenesis and functions of lncRNAs in CRC; 3, The interactions among lncRNAs, miRNAs and mRNA in tumorigensis, growth, progression, EMT formation, chemoradiotherapy resistance, and therapeutic potential in CRC. We believe that identifying diverging lncRNAs, miRNAs and relevant genes, their interactions and complex molecular regulatory networks will provide important clues for understanding the mechanism and developing novel diagnostic and therapeutic strategies for CRC. Further efforts are warranted to bring the promise of regulating their activities into clinical utilities.

Overexpression of miR-222-3p Promotes the Proliferation and Inhibits the Apoptosis of Diffuse Large B-Cell Lymphoma Cells via Suppressing PPP2R2A

PURPOSE

This study aimed to investigate the effects of microRNA-222-3p on activated B cell-like-type diffuse large B-cell lymphoma cells and the regulatory relationship between microRNA-222-3p and phosphatase 2 regulatory subunit B alpha.

METHOD

The expression of microRNA-222-3p was detected in activated B cell-like-type diffuse large B-cell lymphoma tissues and cells by quantitative reverse transcription polymerase chain reaction. The regulatory effects of microRNA-222-3p on the proliferation, invasion, and apoptosis of activated B cell-like-type diffuse large B-cell lymphoma cells were analyzed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), colony formation, flow cytometry, and Transwell assay. The regulatory relationship between microRNA-222-3p and phosphatase 2 regulatory subunit B alpha was determined by luciferase reporter gene and RNA pull-down assay. In addition, the effects of microRNA-222-3p on tumor growth were further analyzed in mice.

RESULTS

MicroRNA-222-3p and phosphatase 2 regulatory subunit B alpha were significantly up- and downregulated in activated B cell-like-type diffuse large B-cell lymphoma tissues and cells, respectively. Phosphatase 2 regulatory subunit B alpha was a target of microRNA-222-3p. MicroRNA-222-3p promoted the proliferation and invasion and inhibited the apoptosis of activated B cell-like-type diffuse large B-cell lymphoma cells. Phosphatase 2 regulatory subunit B alpha reversed the tumor-promoting effects of microRNA-222-3p on activated B cell-like-type diffuse large B-cell lymphoma cells. In addition, microRNA-222-3p promoted the tumor growth in mice and downregulated phosphatase 2 regulatory subunit B alpha in tumor tissues.

CONCLUSION

MicroRNA-222-3p promoted the proliferation and invasion and inhibited the apoptosis of activated B cell-like-type diffuse large B-cell lymphoma cells through suppressing phosphatase 2 regulatory subunit B alpha expression.

A data-driven, knowledge-based approach to biomarker discovery: application to circulating microRNA markers of colorectal cancer prognosis

Recent advances in high-throughput technologies have provided an unprecedented opportunity to identify molecular markers of disease processes. This plethora of complex-omics data has simultaneously complicated the problem of extracting meaningful molecular signatures and opened up new opportunities for more sophisticated integrative and holistic approaches. In this era, effective integration of data-driven and knowledge-based approaches for biomarker identification has been recognised as key to improving the identification of high-performance biomarkers, and necessary for translational applications. Here, we have evaluated the role of circulating microRNA as a means of predicting the prognosis of patients with colorectal cancer, which is the second leading cause of cancer-related death worldwide. We have developed a multi-objective optimisation method that effectively integrates a data-driven approach with the knowledge obtained from the microRNA-mediated regulatory network to identify robust plasma microRNA signatures which are reliable in terms of predictive power as well as functional relevance. The proposed multi-objective framework has the capacity to adjust for conflicting biomarker objectives and to incorporate heterogeneous information facilitating systems approaches to biomarker discovery. We have found a prognostic signature of colorectal cancer comprising 11 circulating microRNAs. The identified signature predicts the patients' survival outcome and targets pathways underlying colorectal cancer progression. The altered expression of the identified microRNAs was confirmed in an independent public data set of plasma samples of patients in early stage vs advanced colorectal cancer. Furthermore, the generality of the proposed method was demonstrated across three publicly available miRNA data sets associated with biomarker studies in other diseases.

Irradiation of rainbow trout at early life stages results in a proteomic legacy in adult gills. Part B; the effect of a second radiation dose, after one year, on the proteomic responses in the irradiated and non-irradiated bystander fish

This study extends the investigation of the legacy effects of exposure to a single radiation dose at one of four early life stages, in adult rainbow trout (Part A), by examining the effects of a second identical dose after one year; i.e. egg 48 h after fertilisation (48 h egg) + 1 year, eyed egg + 1 year, yolk sac larvae (YSL) + 1 year and first feeder + 1 year. This included the induction of a bystander effect in non-irradiated trout which had swam with the irradiated fish. The second radiation dose negated any beneficial proteomic responses following early life stage irradiation only, particularly irradiation of 48 h eggs and eyed eggs (Part A). Instead the responses after early life stage + 1 year irradiation are consistently associated with tumorigenesis, cancer progression, or are otherwise damaging: upregulation of alpha-globin 1 (YSL + 1 year and first feeders + 1 year) and downregulation of histone H1, type II keratin, malate dehydrogenase 2-2, Na/K ATPase alpha subunit isoform 1b, nucleoside diphosphate kinase (48 h egg + 1 year), electron transfer flavoprotein subunit alpha (eyed egg + 1 year), 60 S ribosomal protein L30 (YSL + 1 year) and haemoglobin subunit beta-4 (first feeder + 1 year). Most significantly the second radiation dose also negated the overwhelmingly beneficial bystander effect proteomic responses induced by trout irradiated at an early life stage only (Part A). Instead the bystander effect proteomic changes induced by trout irradiated at an early life stage and again at 1 year have been associated with uncertain, with respect to tumorigenesis, or detrimental effects; upregulation of alpha-globin 1 (YSL + 1 year and first feeder + 1 year) and downregulation of malate dehydrogenase 2-2, nucleoside diphosphate kinase (48 h egg + 1 year), transferrin precursor (eyed egg + 1 year), 60 S ribosomal protein L30 (YSL + 1 year) and serine / threonine-protein phosphatase 2 A 65 kDa (first feeder + 1 year). This difference between the bystander effect induced proteomic changes following early life stage irradiation only and early life stage + 1 year irradiation may indicate a fundamental change in the non-targeted effects of radiation following multiple exposure to radiation.

Upregulation of miR-614 promotes proliferation and inhibits apoptosis in ovarian cancer by suppressing PPP2R2A expression

It has previously been demonstrated that microRNAs (miRNAs) have essential roles and participate in various biological processes by regulating their specific target genes. However, the precise role of miRNAs in ovarian cancer (OC) has not yet been elucidated. The present study demonstrated that miR‑614 expression levels were significantly upregulated in OC tissues and cell lines, whereas decreased miR‑614 demonstrated opposite effects. Furthermore, gain‑of‑function and loss‑of‑function experiments indicated that miR‑614 overexpression promoted cell proliferation and suppressed cell apoptosis. Protein phosphatase 2 regulatory subunit B α, (PPP2R2A) was identified as a direct target of miR‑614 using western blotting and luciferase reporter assays. Notably, silencing of PPP2R2A counter‑acted the effect of miR‑614 inhibitor in OC cell proliferation and cell apoptosis. Overall, the data suggested that miR‑614 promoted cell proliferation and inhibited cell apoptosis of OC cells by targeting PPP2R2A, and may therefore act as a potential target for OC therapy in the future.

microRNA-544 promoted human osteosarcoma cell proliferation by downregulating AXIN2 expression

microRNAs (miRNAs) perform various oncogenic or tumor suppressor functions in carcinogenesis. Currently, the underlying mechanisms of miRNAs in osteosarcoma (OS) are poorly understood. In the present study, it is demonstrated that expression of miR-544 was markedly upregulated in OS cells and clinical tissues. Furthermore, overexpression of miR-544 enhanced OS cell proliferation in vitro. Bioinformatics analysis indicated that miR-544 may target the 3′-untranslated region of axis formation inhibitor 2, which was validated using luciferase reporter gene assays. The present study demonstrated a vital role for miR-544 in promoting OS cell proliferation, indicating that it may represent a novel prognostic factor or therapeutic target for OS.

Characterization and Evidence of the miR-888 Cluster as a Novel Cancer Network in Prostate

Prostate cancer afflicts 1 in 7 men and is the second leading cause of male cancer-related deaths in the United States. MicroRNAs (miRNAs), an extensive class of approximately 22 nucleotide noncoding RNAs, are often aberrantly expressed in tissues and fluids from prostate cancer patients, but the mechanisms of how specific miRNAs regulate prostate tumorigenesis and metastasis are poorly understood. Here, miR-888 was identified as a novel prostate factor that promotes proliferation and migration. miR-888 resides within a genomic cluster of 7 miRNA genes (mir-892c, mir-890, mir-888, mir-892a, mir-892b, mir-891b, mir-891a) on human chromosome Xq27.3. Moreover, as miR-888 maps within HPCX1, a locus associated with susceptibility and/or hereditary prostate cancer, it was hypothesized that additional miRNA cluster members also play functional roles in the prostate. Expression analysis determined that cluster members were similarly elevated in metastatic PC3-ML prostate cells and their secreted exosomes, as well as enriched in expressed prostatic secretions urine-derived exosomes obtained from clinical patients with high-grade prostate cancer. In vitro assays revealed that miR-888 cluster members selectively modulated PC3-derived and LNCaP cell proliferation, migration, invasion, and colony formation. Mouse xenograft studies verified miR-888 and miR-891a as pro-oncogenic factors that increased prostate tumor growth in vivo Further analysis validated RBL1, KLF5, SMAD4, and TIMP2 as direct miR-888 targets and that TIMP2 is also coregulated by miR-891a. This study provides the first comprehensive analysis of the entire miR-888 cluster and reveals biological insight.Implications: This work reveals a complex noncoding RNA network in the prostate that could be developed as effective diagnostic and therapeutic tools for advanced prostate cancer. Mol Cancer Res; 16(4); 669-81. ©2018 AACR.

Upregulation of miR‑598 promotes cell proliferation and cell cycle progression in human colorectal carcinoma by suppressing INPP5E expression

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. Recently, microRNAs (miRs) have been considered as novel therapeutic targets for the treatment of cancer. miR‑598 is a poorly investigated miR. The underlying mechanism of miR‑598 in CRC cells remains to be elucidated. In the present study, miR‑598 was demonstrated to be significantly upregulated in CRC tissue by analyzing data from The Cancer Genome Atlas and the Gene Expression Omnibus. The results of a polymerase chain reaction demonstrated that miR‑598 expression was significantly upregulated in CRC tissues and cells. Gain of function and loss of function assays demonstrated that miR‑598 significantly promoted cell proliferation and cell cycle progression. miR‑598 was demonstrated to modulate cell functions by regulating 72 kDa inositol polyphosphate‑5‑phosphatase (INPP5E). In addition, knockdown of INPP5E counteracted the growth arrest caused by an miR‑598‑inhibitor. In conclusion, the present study demonstrated that miR‑598 contributed to cell proliferation and cell cycle progression in CRC by targeting INPP5E.

MiR-892a Promotes Hepatocellular Carcinoma Cells Proliferation and Invasion Through Targeting CD226

Our study is aim to investigate the influence of miR-892a on proliferative and invasive activities of human hepatocellular carcinoma (HCC) cells through regulating CD226 expression. QRT-PCR was used to detect the expression levels of miR-892a and CD226 mRNA in HCC tissues and adjacent tissues or HCC cells and normal cells whereas Western Blot was used to detect the CD226 protein expression in tissue and cell samples. Then HuH-7 cell line was selected for following assays and respectively transfected with miR-892a mimics, miR-NC, Plenti-GIII-Ubc-CD226, and Plenti-GIII-Ubc followed by qRT-PCR assay to detect the miR-892a and CD226 expression. The luciferase reporter assay was conducted to determine if miR-892a directly targeted CD226 and then CCK-8 assay, wound healing assay, Transwell assay, and flow cytometry were used to detect cell proliferation, migration, invasion ability, cell cycle, and cell apoptosis. What's more, relationships between expression levels of miR-892a or CD226 and overall survival (OS) or disease-free survival (DFS) of HCC patients were investigated based on TCGA database. MiR-892a was high-expressed in HCC tissues or cells while CD226 was low-expressed. MiR-892a directly targeted CD226 and up-regulating miR-892a expression could promote proliferative, migrating, and invasive activities of HCC cells. Different expression levels of miR-892a and CD226 both related to the prognosis of HCC. MiR-892a promotes hepatocellular carcinoma cells proliferation and invasion through regulating CD226 expression. J. Cell. Biochem. 118: 1489-1496, 2017. © 2016 Wiley Periodicals, Inc.

MiR-639 promoted cell proliferation and cell cycle in human thyroid cancer by suppressing CDKN1A expression

Accumulating evidence has indicated that aberrantly expressed microRNAs (miRs) are extensively involved in cancer development and progression. MiR-639 has been reported to act as tumor promoter in various types of cancer. However, the biological function and underlying molecular mechanism of miR-639 in thyroid carcinoma (TC) have not been intensively investigated. Herein the present study aimed to investigate the functional role of miR-639 in TC. We found that miR-639 expression was upregulated in TC cells and clinical tissues. Overexpression of miR-639 promoted TC cell proliferation and cell cycle, with increased expression of CyclinE and c-myc, whereas miR-639-in reverses the function. Using prediction software and luciferase reporter assay, we found that CDKN1A was a target of miR-639. CDKN1A small interfering RNA (siRNA) abrogated the role of miR-639-in on cell proliferation of TC. In summary, our data demonstrated that miR-639 upregulation was associated with development of TC, miR-639 promoted cell proliferation and cell cycle by targeting CDKN1A in TC.