MicroRNA-15a inhibits the growth and invasiveness of malignant melanoma and directly targets on CDCA4 gene

Predicting regulatory mutations and their target genes by new computational integrative analysis: A study of follicular lymphoma

Mutations in DNA regulatory regions are increasingly being recognized as important drivers of cancer and other complex diseases. These mutations can regulate gene expression by affecting DNA-protein binding and epigenetic profiles, such as DNA methylation in genome regulatory elements. However, identifying mutation hotspots associated with expression regulation and disease progression in non-coding DNA remains a challenge. Unlike most existing approaches that assign a mutation score to individual single nucleotide polymorphisms (SNP), a mutation block (MB)-based approach was introduced in this study to assess the collective impact of a cluster of SNPs on transcription factor-DNA binding affinity, differential gene expression (DEG), and nearby DNA methylation. Moreover, the long-distance target genes of functional MBs were identified using a new permutation-based algorithm that assessed the significance of correlations between DNA methylation at regulatory regions and target gene expression. Two new Python packages were developed. The Differential Methylation Region (DMR-analysis) analysis tool was used to detect DMR and map them to regulatory elements. The second tool, an integrated DMR, DEG, and SNP analysis tool (DDS-analysis), was used to combine the omics data to identify functional MBs and long-distance target genes. Both tools were validated in follicular lymphoma (FL) cohorts, where not only known functional MBs and their target genes (BCL2 and BCL6) were recovered, but also novel genes were found, including CDCA4 and JAG2, which may be associated with FL development. These genes are linked to target gene expression and are significantly correlated with the methylation of nearby DNA sequences in FL. The proposed computational integrative analysis of multiomics data holds promise for identifying regulatory mutations in cancer and other complex diseases.

CDCA3 is a prognostic biomarker for cutaneous melanoma and is connected with immune infiltration

Introduction

Dysregulation of cell cycle progression (CCP) is a trait that distinguishes cancer from other diseases. In several cancer types, CCP-related genes serve as the primary risk factor for prognosis, but their role in cutaneous melanoma remains unclear.

Methods

Data from cutaneous melanoma patients were acquired from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Using a Wilcoxon test, the level of CCP-related gene expression in cutaneous melanoma patient tissues was compared to that in normal skin tissues. Logistic analysis was then utilized to calculate the connection between the CCP-related genes and clinicopathological variables. The important functions of the CCP-related genes were further investigated using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and single-sample Gene Set Enrichment Analysis (ssGSEA). Univariate and multivariate Cox analyses and Kaplan-Meier analysis were used to estimate the association between CCP-related genes and prognosis. In addition, using Cox multivariate analysis, a nomogram was constructed to forecast the influence of CCP-related genes on survival rates.

Results

High expression of CCP-related genes was associated with TNM stage, age, pathological grade, and Breslow depth (P < 0.05). Multivariate analysis demonstrated that CCP-related genes were an independent factor in overall survival and disease-specific survival. High levels of gene expression originating from CCP were shown by GSEA to trigger DNA replication, the G1-S specific transcription factor, the mitotic spindle checkpoint, and the cell cycle. There was a negative association between CCP-related genes and the abundance of innate immune cells. Finally, we revealed that knockdown of cell division cycle-associated gene 3 (CDCA3) significantly suppressed the proliferation and migration ability of cutaneous melanoma cells.

Conclusion

According to this study, CCP-related genes could serve as potential biomarkers to assess the prognosis of cutaneous melanoma patients and are crucial immune response regulators.

Regulators CDCA8 as potential targets and biomarkers for the prognosis of human skin cutaneous melanoma

Cutaneous melanoma (CM) is considered as the most malignant skin tumor with high distant metastasis and poor prognosis. Cell division cycle-associated protein (CDCA) family has a role in regulating cell proliferation and modulating immune cell and tumor cell proliferation in the tumor microenvironment to regulate tumor oncogenesis, development and affect patient outcomes. However, the differential expression pattern and prognostic value of CDCA factors (CDCAs) have not been clarified. In this study, the role of CDCAs in CM was analyzed by using bioinformatics and found that the transcriptional expressions of CDCA1/2/3/5/6/8 were upregulating in CM samples than in normal compares. CM patients with downregulated of CDCA1/3/4/5/6/8 and high transcriptional levels of CDCA7 suggest a significantly better prognosis. Furthermore, the significant correlations among the expression of CDCAs and the infiltration of immune cells. In terms of the protein level, we found CDCA8 was upregulated in CM patients. In conclusion, CDCA8 is a powerful prognostic biomarker for CM and can be a novel target for immunotherapy.

CDCA4 as a novel molecular biomarker of poor prognosis in patients with lung adenocarcinoma

Background

Because of the high incidence and poor prognoses of lung adenocarcinoma (LUAD), it is essential to identify cost-effective treatment options and accurate and reliable prognostic biomarkers. CDCA4 upregulation has been identified in many cancers. However, the prognostic importance of CDCA4 and its role in LUAD remain unknown.

Methods

CDCA4 expression was assessed through IHC, Western blotting (WB) and RT-PCR. The Cancer Genome Atlas (TCGA) provided data from 513 patients to study the expression and prognostic relevance of CDCA4 in LUAD. This study used gene set enrichment analyses (GSEA), gene ontology and KEGG pathway analyses for elucidating potential mechanisms underpinning the function of CDCA4 in LUAD. We also investigated correlations between immune infiltration and CDCA4 expression with single specimen GSEA (ssGSEA).

Results

According to database analysis and identification of patient tissue samples, CDCA4 expression in tumour tissues surpassed that in normal tissues (P< 0.001). Increased CDCA4 expression was positively correlated with a higher T, N, pathologic stage and poor primary therapy outcome. In addition, the Kaplan–Meier plotter exhibited that an elevated CDCA4 expression was related to worse disease-specific survival(DSS) and overall survival (OS) (DSS HR= 5.145, 95% CI=3.413-7.758, P<0.001; OS HR=3.570, 95% CI=2.472-5.155, P<0.001). Then multivariate COX regression analyses indicated that the CDCA4 gene was an independent risk consideration for prognoses. GO and KEGG results showed that CDCA4 and its neighbouring genes were enriched in the cell cycle and DNA replication. As determined by GSEA, CDCA4 was related to various immune-related signalling pathways (SPs), Homologous recombination, DNA replication and the cell cycle. SsGSEA analysis showed a significant association between CDCA4 expression and Th2 cells, mast cells, eosinophils and Th17 cells.

Conclusions

CDCA4 expression is increased in LUAD and is a potential predictive biomarker and therapeutic target.

Identification of a Tumor Cell Associated Type I IFN Resistance Gene Expression Signature of Human Melanoma, the Components of Which Have a Predictive Potential for Immunotherapy

We developed a human melanoma model using the HT168-M1 cell line to induce IFN-α2 resistance in vitro (HT168-M1res), which was proven to be maintained in vivo in SCID mice. Comparing the mRNA profile of in vitro cultured HT168-M1res cells to its sensitive counterpart, we found 79 differentially expressed genes (DEGs). We found that only a 13-gene core of the DEGs was stable in vitro and only a 4-gene core was stable in vivo. Using an in silico cohort of IFN-treated melanoma tissues, we validated a differentially expressed 9-gene core of the DEGs. Furthermore, using an in silico cohort of immune checkpoint inhibitor (ICI)-treated melanoma tissues, we tested the predictive power of the DEGs for the response rate. Analysis of the top four upregulated and top four downregulated genes of the DEGs identified WFDC1, EFNA3, DDX10, and PTBP1 as predictive genes, and analysis of the "stable" genes of DEGs for predictive potential of ICI response revealed another 13 genes, out of which CDCA4, SOX4, DEK, and HSPA1B were identified as IFN-regulated genes. Interestingly, the IFN treatment associated genes and the ICI-therapy predictive genes overlapped by three genes: WFDC1, BCAN, and MT2A, suggesting a connection between the two biological processes.

Microribonucleic Acid-15a-5p Alters Adriamycin Resistance in Breast Cancer Cells by Targeting Cell Division Cycle-Associated Protein 4

Objective

Although chemotherapy is one of the first line clinical treatment of tumors, the efficacy of chemotherapy has been severely restricted by the frequent occurrence of drug resistance phenomenon. Multiple studies found that miRNAs can regulate the chemosensitivity of tumor cells. Here, this study aimed to assess the potential role of the miR-15a-5p/cell division cycle-related protein 4 (CDCA4) axis in breast cancer (BC) resistance to Adriamycin.

Methods

In the present study, the relative expression of miRNA-15a-5p in MCF-7/ADR, MCF-7 and Hs578Bst was measured by qRT-PCR. MCF-7/ADR cells underwent transfection with an miR-15a-5p mimic and inhibitor, respectively. Transwell assays, flow cytometry and CCK8 were performed to examine the potential effects of the abnormal expression of miR-15a-5p. The association of aberrant miR-15a-5p expression with Adriamycin resistance in BC was determined in cultured MCF-7/ADR cells. Bioinformatics was employed to predict the genes targeted by miR-15a-5p. Moreover, the correlation between miR-15a-5p and its target gene, CDCA4, was evaluated based on qRT-PCR data.

Results

The expression of miR-15a-5p was significantly downregulated in MCF/ADR cells compared with MCF-7 and Hs578Bst cell lines. In the presence of Adriamycin, miR-15a-5p overexpression significantly increased cell chemosensitivity, as well as MCF-7/ADR cell proliferation, invasion, and migration, while promoting apoptosis and inducing cell-cycle arrest in the synthesis phase. CDCA4 RNA interference enhanced these effects as shown in our previous study. Bioinformatics identified CDCA4 as an miR-15a-5p target gene. qRT-PCR further demonstrated that CDCA4 and miR-15a-5p expression levels were inversely correlated.

Conclusion

Adriamycin resistance in BC cells was, at least in part, altered by mRNA-15a-5p via regulation of its target gene, CDCA4, by controlling the cell cycle, which may provide some novel ideas for BC chemotherapy in the future.

Identification of common microRNA between COPD and non-small cell lung cancer through pathway enrichment analysis

BACKGROUND

Different factors have been introduced which influence the pathogenesis of chronic obstructive pulmonary disease (COPD) and non-small cell lung cancer (NSCLC). COPD as an independent factor is involved in the development of lung cancer. Moreover, there are certain resemblances between NSCLC and COPD, such as growth factors, activation of intracellular pathways, as well as epigenetic factors. One of the best approaches to understand the possible shared pathogenesis routes between COPD and NSCLC is to study the biological pathways that are activated. MicroRNAs (miRNAs) are critical biomolecules that implicate the regulation of several biological and cellular processes. As such, the main goal of this study was to use a systems biology approach to discover common dysregulated miRNAs between COPD and NSCLC, one that targets most genes within common enriched pathways.

RESULTS

To reconstruct the miRNA-pathways for each disease, we used the microarray miRNA expression data. Then, we employed "miRNA set enrichment analysis" (MiRSEA) to identify the most significant joint miRNAs between COPD and NSCLC based on the enrichment scores. Overall, our study revealed the involvement of the targets of miRNAs (such as has-miR-15b, hsa-miR-106a, has-miR-17, has-miR-103, and has-miR-107) in the most important common biological pathways.

CONCLUSIONS

According to the promising results of the pathway analysis, the identified miRNAs can be utilized as the new potential signatures for therapy through understanding the molecular mechanisms of both diseases.

Upregulation of miR-29c-3p Hinders Melanoma Progression by Inhibiting CDCA4 Expression

OBJECTIVE

To investigate the expression and regulation mechanism of miR-29c-3p and cell division cycle associated 4 (CDCA4) in melanoma (MM). Data and Methods. Fifty-nine patients with MM admitted to our hospital were enrolled as the MM group. They were followed up for 3 years to analyze the prognostic factors; meanwhile, 51 healthy subjects were allocated into a normal group. MM cell lines (M21 and C8161) were transfected with miR-29c-3p-mimics, miR-29c-3p-inhibitor, miR-NC, si-CDCA4, and sh-CDCA4. The expression of miR-29c-3p, CDCA4, Bax, Caspase3, Bcl-2, N-cadherin, vimentin, and E-cadherin was quantified, and cell proliferation, migration, invasion, and apoptosis, as well as epithelial-mesenchymal transition (EMT), were determined.

RESULTS

Serum miR-29c-3p was lowly expressed and CDCA4 was highly expressed in the MM group. The area under the curve (AUC) of both for diagnosing MM was greater than 0.9. miR-29c-3p and CDCA4 were related to regional lymph node staging (N staging), distant metastasis (M staging), tumor diameter, and pathological differentiation. Low miR-29c-3p and high CDCA4 were associated with poor prognosis of MM. Overexpression of miR-29c-3p and suppression of CDCA4 hindered cell proliferation, migration, invasion, and expression of Bax, Caspase3, N-cadherin, and vimentin, but cell apoptosis and expression of Bcl-2 and E-cadherin were enhanced. Dual-luciferase reporter (DLR) assay confirmed the targeted relationship between miR-29c-3p and CDCA4. After miR-29c-3p-mimics+sh-CDCA4 was transfected into M21 and C8161 cells, the proliferation, invasion, and apoptosis were not different from those in the miR-NC group transfected with unrelated sequences.

CONCLUSION

Overexpression of miR-29c-3p suppresses CDCA4 expression and decreases proliferation, migration, invasion, apoptosis, and EMT of MM cells, thus hindering MM progression.

Exosomes miR-15a promotes nucleus pulposus-mesenchymal stem cells chondrogenic differentiation by targeting MMP-3

The physiology of the nucleus pulposus (NP) in intervertebral disc degeneration (IVD) has been studied widely. However, interactions involving nucleus pulposus -mesenchymal stem cells (NP-MSCs) are less understood. MicroRNA 15a (miR-15a) is known to target and modulate genes involved in cellular proliferation and apoptosis. This study aimed to understand the interactions and impact of miR-15a and NP-MSCs on chondrogenic differentiation and IVD degeneration. Exosomes secreted by NP cells were purified by differential centrifugation and identified by transmission electron microscopy and exosomal markers. Further, by co-culture these exosomes were re-introduced into the NP-MSC cells, which were confirmed by fluorescence confocal microscopy. NP-MSCs treated with exo-miR-15a increases aggrecan and collagen II mRNA and protein levels while decreasing mRNA and protein levels of ADAMTS4/5 and MMP-3/-13. Toluidine blue staining confirmed that chondrogenic differentiation was increased in NP-MSCs treated with exo-miR-15a. NP-MSCs treated with exo-anti-miR-15a inhibit aggrecan and collagen II expression while increasing ADAMTS4/5 and MMP-3/-13 expression and decreasing chondrogenic differentiation. Dual-luciferase reporter assays revealed that miR-15a directly targets MMP-3 and downregulates its expression. Overexpression of miR-15a increased proliferation and colony formation, whereas combinatorial overexpression with MMP3, suppressed miR-15a's effects. This was also evident through the decreased phosphorylation of PI3K and Akt, upregulation of Wnt3a and β-catenin in the presence of miR-15a, but overexpression of MMP3 indicated an opposite effect. Overall, these data demonstrate that exo-miR-15a promotes NP-MSCs chondrogenic differentiation by downregulating MMP-3 through PI3K/Akt and Wnt3a/β-catenin axis.

Long non-coding RNA LINC01116 is activated by EGR1 and facilitates lung adenocarcinoma oncogenicity via targeting miR-744-5p/CDCA4 axis

Background

Lung adenocarcinoma (LAD) is one of the most frequently diagnosed pathological categories of human lung cancer. Nevertheless, the link between long non-coding RNA (lncRNA) LINC01116 and LAD remains poorly investigated.

Methods

QRT-PCR and western blot were applied for quantifying the expression of RNAs and proteins. Both functional experiments assays in vitro and xenografts model in vivo were implemented for analyzing LINC01116 function in LAD while molecular relationship among RNAs was investigated via mechanism experiments.

Results

LINC01116 was expressed at an abnormally high level in LAD, which was induced by transcription activator EGR1. LINC01116 depletion restrained proliferation, migration and invasion, yet facilitated apoptosis of LAD cells. MiR-744-5p could bind to LINC01116. MiR-744-5p inhibitor reversed the inhibitory effects of silencing LINC01116 on LAD malignant behaviors. In addition, cell division cycle-associated protein 4 (CDCA4) shared binding sites with miR-744-5p. Silencing LINC01116 elicited decline in CDCA4 mRNA and protein levels. Moreover, CDCA4 up-regulation could counteract the biological effects of LINC01116 knockdown on LAD cells.

Conclusion

Our data revealed that LINC01116 promoted malignant behaviors of LAD cells by targeting miR-744-5p/CDCA4 axis, implying the theoretical potential of LINC01116 as a novel target for LAD treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01994-w.

MicroRNA Signature in Melanoma: Biomarkers and Therapeutic Targets

Melanoma is the utmost fatal kind of skin neoplasms. Molecular changes occurring during the pathogenic processes of initiation and progression of melanoma are diverse and include activating mutations in BRAF and NRAS genes, hyper-activation of PI3K/AKT pathway, inactivation of p53 and alterations in CDK4/CDKN2A axis. Moreover, several miRNAs have been identified to be implicated in the biology of melanoma through modulation of expression of genes being involved in these pathways. In the current review, we provide a summary of the bulk of information about the role of miRNAs in the pathobiology of melanoma, their possible application as biomarkers and their emerging role as therapeutic targets for this kind of skin cancer.

The roles of the cell division cycle-associated gene family in hepatocellular carcinoma

Background

The members of the cell division cycle-associated (CDCA) gene family are significant regulators of cell proliferation known to play key roles in various cancers. However, the function of CDCA genes in hepatocellular carcinoma (HCC) is unclear. The aim of this research was to clarify the roles of CDCA family members in HCC using bioinformatics analysis tools.

Methods

We studied data on the mRNA and protein expression of CDCA genes and survival in patients with HCC using the Oncomine, UALCAN, HPA, CCLE, LinkedOmics, cBioPortal, and Metascape databases.

Results

Significant overexpression of all CDCA members was found in HCC tissues. The expression levels of CDCAs were related to the tumor stage, and high expression levels were correlated with a low survival rate in patients with HCC. Also, we observed a high mutation rate (45%) of CDCAs in the HCC samples, which manifested as deep deletion, amplification, or increased mRNA expression. In the correlation analysis, we found that any 2 CDCA members were significantly positively correlated with each other. Cycle-related genes including AHCTF1, AKT1, BIRC5, CENPF, CENPL, and CENPQ were closely associated with CDCA gene alterations.

Conclusions

The findings of this study indicate that CDCAs may be potential therapeutic targets and prognostic indicators for patients with HCC.

Comprehensive Analysis of Aerobic Exercise-Related Genes Identifies CDCA4 That Promotes the Progression of Osteosarcoma

Background

Exercise has a positive impact on patients with osteosarcoma, improving function, reducing disability, maintaining independence and quality of life. Exercise may also directly affect the effectiveness of cancer treatment. Cell division cycle-associated protein 4 (CDCA4) is reported to function importantly during numerous human cancers development. Nevertheless, the details toward CDCA4 function are still to be investigated.

Methods

This study comprehensively analyzed the GSE74194 database and obtained aerobic exercise-related genes. Protein-protein interaction network (PPI) and Gene Ontology (GO) analysis were performed on the differentially expressed genes (DEGs). Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and tumor genome atlas (TCGA) data mining were applied to measure aerobic exercise-related gene CDCA4 level in osteosarcoma tissue. We conducted lots of functional experiments to uncover CDCA4 function and its corresponding mechanism in osteosarcoma.

Results

We screened a total of 547 DEGs related to aerobic exercise, of which 373 were up-regulated and 174 were down-regulated. PPI analysis revealed 90 genes that might play key roles. GO analysis showed that aerobic exercise-related DEGs were significantly enriched during the mitotic cell cycle, cell division, mitotic nuclear division and sister chromatid segregation, nuclear division, microtubule cytoskeleton organization involved protein, microtubule-based process, spindle organization, G2/M transition of mitotic cell cycle. Our results indicated that CDCA4 was increased in osteosarcoma tissues and cell lines, and its level had association with high mortality of osteosarcoma patients. Further studies revealed that absence of CDCA4 largely hindered osteosarcoma cancer cell proliferation, invasion, and migration.

Conclusion

Comprehensive bioinformatics analysis improves our understanding of the underlying molecular mechanisms of aerobic exercise on osteosarcoma. This provides evidence for the effect of aerobic exercise on CDCA4 expression. Our data suggested that CDCA4 could facilitate osteosarcoma development, and gave a hint that CDCA4 was a candidate target in the treatment of osteosarcoma, aerobic exercise might help the treatment and prognosis of patients with osteosarcoma.

Exploring the Role of TRIP-Brs in Human Breast Cancer: An Investigation of Expression, Clinicopathological Significance, and Prognosis

TRIP-Brs, a group of transcription factors (TFs) that modulate several mechanisms in higher organisms. However, the novel paradigm to target TRIP-Brs in specific cancer remains to be deciphered. In particular, comprehensive analysis of TRIP-Brs in clinicopathological and patients’ prognosis, especially in breast cancer (BRCA), is being greatly ignored. Therefore, we explored the key roles of TRIP-Br expression, modulatory effects, mutations, immune infiltration, and prognosis in BRCA using multidimensional approaches. We found elevated levels of TRIP-Brs in numerous cancer tissues than normal. Higher expression of TRIP-Br-2/4/5 was shown to be positively associated with lower survival, tumor grade, and malignancy of patients with BRCA. Additionally, higher TRIP-Br-3/4 were also significantly linked with worse/short survival of BRCA patients. TRIP-Br-1/4/5 were significantly overexpressed and enhanced tumorigenesis in large-scale BRCA datasets. The mRNA levels of TRIP-Brs have been also correlated with tumor immune infiltrate in BRCA patients. In addition, TRIP-Brs synergistically play a pivotal role in central carbon metabolism, cancer-associated pathways, cell cycle, and thyroid hormone signaling, which evoke that TRIP-Brs may be a potential target for the therapy of BRCA. Thus, this investigation may lay a foundation for further research on TRIP-Br-mediated management of BRCA.

Circ_0010220-mediated miR-503-5p/CDCA4 axis contributes to osteosarcoma progression tumorigenesis

CircRNAs are reported to exert a significant role in modulating genes in cancers, including osteosarcoma progression. Up to now, the function of circ_0010220 in osteosarcoma is still poorly known. The aim of our work was to figure out the potential mechanism of circ_0010220/miR-503-5p/CDCA4 axis in osteosarcoma progression. Firstly, quantitative RT-qPCR was utilized to measure the expression of circ_0010220 in osteosarcoma cells. Then, osteosarcoma cell proliferation, apoptosis, cell cycle, migration and invasion after loss of circ_0010220 were evaluated using CCK-8, flow cytometry, transwell migration, invasion and tumorigenesis experiments respectively. Circ_0010220 expression was markedly increased in osteosarcoma cells. Additionally, knockdown of circ_0010220 significantly depressed tumor growth. CCK-8 analysis indicated that down-regulation of circ_0010220 inhibited osteosarcoma cells proliferation. Flow cytometry assay showed that knockdown of circ_0010220 induced cell apoptosis and blocked cell cycle in the G1 phase. Meanwhile, cell migration an invasion was reduced by circ_0010220. Furthermore, miR-503-5p was predicted as the target for circ_0010220 and miR-503-5p inhibitors reversed cell growth suppressed through silencing circ_0010220. Then, our study demonstrated that Cell Division Cycle-Associated protein 4 (CDCA4) could be a downstream target of miR-503-5p. Additionally, circ_0010220 down-regulation reduced CDCA4 expression level and the inhibitors of miR-503-5p reversed that. In conclusion, we indicated circ_0010220 can be an important biomarker for osteosarcoma via regulating miR-503-5p and CDCA4.

The New Era of Cancer Immunotherapy: Targeting Myeloid-Derived Suppressor Cells to Overcome Immune Evasion

Suppression of antitumor immune responses is one of the main mechanisms by which tumor cells escape from destruction by the immune system. Myeloid-derived suppressor cells (MDSCs) represent the main immunosuppressive cells present in the tumor microenvironment (TME) that sustain cancer progression. MDSCs are a heterogeneous group of immature myeloid cells with a potent activity against T-cell. Studies in mice have demonstrated that MDSCs accumulate in several types of cancer where they promote invasion, angiogenesis, and metastasis formation and inhibit antitumor immunity. In addition, different clinical studies have shown that MDSCs levels in the peripheral blood of cancer patients correlates with tumor burden, stage and with poor prognosis in multiple malignancies. Thus, MDSCs are the major obstacle to many cancer immunotherapies and their targeting may be a beneficial strategy for improvement the efficiency of immunotherapeutic interventions. However, the great heterogeneity of these cells makes their identification in human cancer very challenging. Since both the phenotype and mechanisms of action of MDSCs appear to be tumor-dependent, it is important to accurately characterized the precise MDSC subsets that have clinical relevance in each tumor environment to more efficiently target them. In this review we summarize the phenotype and the suppressive mechanisms of MDSCs populations expanded within different tumor contexts. Further, we discuss about their clinical relevance for cancer diagnosis and therapy.

Therapeutic effects of oligo-single-stranded DNA mimicking of hsa-miR-15a-5p on multiple myeloma

Despite the fact that a few novel agents improve the outcome of patients, MM remains incurable. Hence, developing a novel treatment strategy may prove to be promising for the clinical management of MM. Noncoding small RNAs, a cluster of RNAs that do not encode functional proteins, have been underlined that play a pivotal role in the pathogenesis of MM. Our previous study indicated that miR-15a acted as a tumor suppressor, which inhibited the cell proliferation and promoted the apoptosis of MM cells. The level of miR-15a was downregulated in MM cells and correlated with inferior outcome of MM patients. In the present study, we first developed an oligo-single-stranded DNA mimicking the sequence of hsa-miR-15a-5p (OMM-15a) and modified with locked nucleic acid (LNA-15a) to evaluate its anti-MM effects. Our results indicated that the LNA-15a presented an exciting anti-MM effect that showed notable cell growth suppression and apoptosis promotion in MM and other cancer cell lines through downregulating the expression level of target genes BCL-2, VEGF-A, and PHF19. Moreover, LNA-15a treatment significantly improved the anti-MM activity of bortezomib with the synergism effect in OCI-My5 MM cells. In our in vivo study, LNA-15a treatment significantly suppressed the tumor growth, and prolonged the survival of mice compared with the control group. However, our results indicated that the native form of oligo-single-stranded DNA mimic of hsa-miR-15a-5p (OMM-15a) without any modification had no effective inhibition on cell growth, even after increasing the dosage of OMM-15a in the treatment. Altogether, our finding provides the preclinical rationale to support the oligo-single-stranded DNA mimic of hsa-miR-15a with LNA modification, which is a promising tool for the therapy of both MM and other tumors with miR-15a downregulation.

Knockdown of cell division cycle-associated protein 4 expression inhibits proliferation of triple negative breast cancer MDA-MB-231 cells in vitro and in vivo

Cell division cycle-associated protein 4 (CDCA4), also known as SEI-3/hematopoietic progenitor protein, is a target gene of transcription factor E2F and represses E2F-dependent transcriptional activation and cell proliferation. The present study investigated the effects of CDCA4 knockdown on the regulation of triple negative breast cancer (TNBC) cell proliferation in vitro and in vivo. Human TNBC MDA-MB-231 cells were subjected to CDCA4 expression knockdown using a lentiviral vector carrying CDCA4 or a negative control short hairpin RNA, and reverse transcription-quantitative polymerase chain reaction, MTT cell viability, cell growth, flow cytometric apoptosis, cell cycle and nude mouse tumorigenesis assays were conducted. The knockdown of CDCA4 expression effectively inhibited the growth of MDA-MB-231 cells by promoting apoptosis in vitro. Additionally, CDCA4 expression knockdown suppressed nude mouse tumor cell xenograft formation and growth in vivo. In conclusion, the data from the present study supported the hypothesis that CDCA4 may be involved in regulating human TNBC progression, and that targeting CDCA4 expression could be useful as a novel strategy in future TNBC treatment.

NOP14 inhibits melanoma proliferation and metastasis by regulating Wnt/β-catenin signaling pathway

Malignant melanoma is an aggressive skin cancer with a high mortality rate. Nucleolar protein 14 (NOP14) has been implicated in cancer development. However, the role of NOP14 in malignant melanoma progression remains largely unclear. In this study, we observed that malignant melanoma tissue showed NOP14 down-regulation compared to melanocytic nevi tissues. Moreover, we observed that NOP14 expression was significantly associated with melanoma tumor thickness and lymph node metastasis. NOP14 overexpression in melanoma cells suppressed proliferation, caused G1 phase arrest, promoted apoptosis, and inhibited melanoma cell migration and invasion. Further investigations revealed that NOP14 overexpression reduced the expression levels of Wnt3a, β-catenin, and GSK-3β of the Wnt/β-catenin pathway. In summary, we demonstrated that NOP14 inhibited melanoma cell proliferation and metastasis by regulating the Wnt/β-catenin signaling pathway.

miR-15a-5p, A Novel Prognostic Biomarker, Predicting Recurrent Colorectal Adenocarcinoma

INTRODUCTION

Colorectal cancer is one of the most common gastrointestinal diseases and the second leading cause of cancer-associated deaths among adults. miR-15a-5p is a post-transcriptional regulator of the proto-oncogene MYB, a transcription factor essential for prolonged cancer cell proliferation and survival. In the current study, we assessed the potential diagnostic and prognostic utility of miR-15a-5p expression in colorectal adenocarcinoma.

METHODS

To accomplish this goal, total RNA was extracted from 182 colorectal adenocarcinoma specimens and 86 non-cancerous colorectal mucosae. After polyadenylation by poly(A) polymerase and subsequent reverse transcription with an oligo-dT adapter primer, miR-15a-5p expression was analyzed using an in-house developed reverse transcription quantitative real-time PCR method, based on SYBR Green chemistry. SNORD43 (RNU43) was used as an internal control gene.

RESULTS

miR-15a-5p was significantly upregulated in colorectal tumors compared to non-cancerous colorectal mucosae, while ROC analysis suggested its potential use for diagnostic purposes. Moreover, miR-15a-5p overexpression predicts poor disease-free survival (DFS) and overall survival (OS). Multivariate Cox regression analysis confirmed that miR-15a-5p overexpression is a significant unfavorable prognosticator of DFS in colorectal adenocarcinoma, independent of other established prognostic factors plus treatment of patients. Importantly, miR-15a-5p overexpression retains its unfavorable prognostic value in patients with T3 colorectal adenocarcinoma and in those without distant metastasis (M0). More importantly, the cumulative DFS probability of patients with early stage disease was significantly lower for those with colorectal adenocarcinoma overexpressing miR-15a-5p.

DISCUSSION

In conclusion, elevated expression of the cancer-associated miR-15a-5p predicts poor DFS and OS of colorectal adenocarcinoma patients. The prognostic value of miR-15a-5p expression regarding DFS is independent of clinicopathological factors currently used for colorectal adenocarcinoma prognosis.

Thrombospondin 1 Triggers Osteosarcoma Cell Metastasis and Tumor Angiogenesis

Osteosarcomas, especially those with metastatic or unresectable disease, have limited treatment options. The antitumor effects of pharmacologic inhibitors of angiogenesis in osteosarcomas are hampered in patients by the rapid development of tumor resistance, notably through increased invasiveness and accelerated metastasis. Here we demonstrated that thrombospondin 1 (TSP-1) is a potent inhibitor of the growth and metastasis of the osteosarcoma cell line MG-63. Moreover, we demonstrate that upregulation of TSP-1 facilitated expression of vasculostatin in MG-63 cells. In angiogenesis assays, overexpression of TSP-1 inhibited MG-63 cells and induced tube formation of human umbilical vein endothelial cells (HUVECs) in a CD36-dependent fashion. Finally, in xenografted tumors, we observed that TSP-1 overexpression inhibited angiogenesis and tumor growth. These results provided strong evidence for an important role of the TSP-1/CD36/vasculostatin signaling axis in mediating the antiangiogenic activity of osteosarcoma.

MicroRNA-Directed Cancer Therapies: Implications in Melanoma Intervention

Acquired tumor resistance to cancer therapies poses major challenges in the treatment of cancers including melanoma. Among several signaling pathways or factors that affect neocarcinogenesis, cancer progression, and therapies, altered microRNAs (miRNAs) expression has been identified as a crucial player in modulating the key pathways governing these events. While studies in the miRNA field have grown exponentially in the last decade, much remains to be discovered, particularly with respect to their roles in cancer therapies. Since immune and nonimmune signaling cascades prevail in cancers, identification and evaluation of miRNAs, their molecular mechanisms and cellular targets involved in the underlying development of cancers, and acquired therapeutic resistance would help in devising new strategies for the prognosis, treatment, and an early detection of recurrence. Importantly, in-depth validation of miRNA-targeted molecular events could lead to the development of accurate progression-risk biomarkers, improved effectiveness, and improved patient responses to standard therapies. The current review focuses on the roles of miRNAs with recent updates on regulated cell cycle and proliferation, immune responses, oncogenic/epigenetic signaling pathways, invasion, metastasis, and apoptosis, with broader attention paid to melanomagenesis and melanoma therapies.

CDCA4, a downstream gene of the Nrf2 signaling pathway, regulates cell proliferation and apoptosis in the MCF‑7/ADM human breast cancer cell line

The present study aimed to examine the effect of RNA interference targeting cell division cycle-associated protein 4 (CDCA4) on the proliferation and apoptosis of the MCF-7/ADR' human breast cancer cell line. CDCA4 has been shown to have a unique role in regulating cell cycle. In the present study, the expression of CDCA4 was suppressed by CDCA4-specific short hairpin (sh)RNA transfection of the human breast cancer cells, following which changes in the proliferation and apoptosis of the CDCA4-knockdown cells were compared with those of control shRNA-transfected cells. The results confirmed that CDCA4 RNA interference reduced the percentage of human breast cancer cells to <50%. In addition, RNA interference of CDCA4 resulted in a significant increase in the apoptotic rate of cells. Taken together, these results suggested that CDCA4 enhanced proliferation and reduced apoptosis in the MCF-7/ADM human breast cancer cells in vitro.

Downregulation of microRNA-15a suppresses the proliferation and invasion of renal cell carcinoma via direct targeting of eIF4E

The downregulation of microRNA-15a has been reported in several human tumors. However, its expression and functional importance in renal cell carcinoma (RCC) remain unknown. The aim of the present study was to investigate its expression, biological functions and underlying mechanisms in RCC tumorigenesis. The expression levels of miR-15a were examined by qRT-PCR in 40 RCC specimens and adjacent‑paired normal tissues. Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry and Transwell assays were used to explore the potential influence of miR-15a transfection on RCC cell proliferation, the cell cycle, cell apoptosis, and cell invasion. Luciferase reporter assays were performed to confirm the potential target of miR-15a, in combination with qRT-PCR, western blotting and immunohistochemical assays. We found that miR-15a was significantly downregulated in most RCC specimens compared with adjacent normal tissues (P<0.01). Overexpression of miR-15a inhibited cellular growth, suppressed invasion and arrested cells at the G1/G0 phase, and induced cell apoptosis in RCC cells. Luciferase assays revealed that miR-15a directly targeted the binding site of the 3'-untranslated region (3'-UTR) of eIF4E, and inhibited its expression at both mRNA and protein levels. eIF4E expression was negatively associated with miR-15a expression in RCC tissues. eIF4E overexpression treatment partially abrogated the inhibitory effect of miR-15a on cell proliferation and invasion, as well as inactivated P13K/AKT/mTOR signaling in RCC cells. In conclusion, the present study indicated that miR-15a downregulation was associated with cell proliferation and invasion by directly targeting eIF4E during RCC progression. Thus, it may serve as a potential tumor suppressor and therapeutic target for the treatment of RCC.

Vitamin C at high concentrations induces cytotoxicity in malignant melanoma but promotes tumor growth at low concentrations

Vitamin C has been used in complementary and alternative medicine for cancers regardless of its ineffectiveness in clinical trials and the paradoxical effects antioxidants have on cancer. Vitamin C was found to induce cytotoxicity against cancers. However, the mechanisms of action have not been fully elucidated, and the effects of vitamin C on human malignant melanoma have not been examined. This study revealed that vitamin C at millimolar concentrations significantly reduced the cell viability as well as invasiveness, and induced apoptosis in human malignant melanoma cells. Vitamin C displayed stronger cytotoxicity against the Vemurafenib-resistance cell line A2058 compared with SK-MEL-28. In contrast, vitamin C at micromolar concentrations promoted cell growth, migration and cell cycle progression, and protected against mitochondrial stress. Vemurafenib paradoxically activated the RAS-RAF-MEK-ERK signaling pathway in the Vemurafenib-resistant A2058, however, vitamin C abolished the activations. Vitamin C displayed synergistic cytotoxicity with Vemurafenib against the Vemurafenib-resistant A2058. In vivo assay suggested that lower dosage (equivalent to 0.5 g/70 kg) of vitamin C administered orally increased the melanoma growth. Therefore, vitamin C may exert pro- or anti-melanoma effect depending on concentration. The combination of vitamin C at high dosage and Vemurafenib is promising in overcoming the action of drug resistance.

Role of miR-15a in intervertebral disc degeneration through targeting MAP3K9

BACKGROUND

Accumulating evidence indicates that microRNAs are involved in various cellular processes, including cell proliferation, differentiation, apoptosis and metastasis. miR-15a is an important regulator of immune responses and angiogenesis, endogenous controls as well as potential targets and hallmarks of cancer. However, the role of miR-15a in intervertebral disc degeneration (IDD) has not been elucidated.

METHODS

Total RNA was extracted from degenerative nucleus pulposus (NP) tissues of 20 patients with IDD and NP cells, respectively. The expression levels of miR-15a were examined by quantitative real-time PCR. The stable overexpress or silence miR-15a expression cell lines and control cell lines were constructed by lentivirus infection. Subsequently, 3-(4,5-dimethylthia zol-2-yl)-2,5-diphenylte trazolium bromide (MTT) assay, flow cytometry test, TdT-mediated dUTP Nick-End Labeling (TUNEL) experiment, colony formation assay and western blot analysis were performed to detect the biological functions of miR-15a. Moreover, a luciferase reporter assay was conducted to confirm its target associations.

RESULTS

Herein, the results found that miR-15a was dramatically up-regulated in degenerative NP tissues and NP cells compared with the controls. Overexpression of miR-15a promoted NP cells proliferation and induced apoptosis. Moreover, apoptosis-related protein caspase-3 was significantly up-regulated and bcl-2 was observably down-regulated when NP cells were transfected with miR-15a mimics, while bax and caspase-3 were significantly down-regulated as well as bcl-2 was observably up-regulated when NP cells were transfected with miR-15a inhibitors. Further, luciferase reporter assay showed that MAP3K9, an upstream activator of MAPK kinase, was putative target of miR-15a. There was a negatively relationship between miR-15a and MAP3K9 expression in NP cells. In addition, knockdown MAP3K9 inhibited NP cells proliferation and promoted apoptosis, which further inhibited the activation of p38 and ERK MAPK pathway.

CONCLUSION

This present study revealed that miR-15a might be considered as a novel therapeutic target for IDD treatment.