microRNA-16 represses colorectal cancer cell growth in vitro by regulating the p53/survivin signaling pathway

The p53/miRNA Axis in Breast Cancer

One of the main health issues in the modern world is cancer, with breast cancer (BC) as one of the most common types of malignancies. Different environmental and genetic risk factors are involved in the development of BC. One of the primary genes implicated in cancer development is the p53 gene, which is also known as the "gatekeeper" gene. p53 is involved in cancer development by interacting with numerous pathways and signaling factors, including microRNAs (miRNAs). miRNAs are small noncoding RNA molecules that regulate gene expression by binding to the 3' untranslated region of target mRNAs, resulting in their translational inhibition or degradation. If the p53 gene is mutated or degraded, it can contribute to the risk of BC by disrupting the expression of miRNAs. Similarly, the disruption of miRNAs causes the negative regulation of p53. Therefore, the p53/miRNA axis is a crucial pathway in the progression or prevention of BC, and understanding the regulation and function of this pathway may contribute to the development of new therapeutic strategies to help treat BC.

Evaluation of survivin expression and regulating miRNAs of survivin expression in peripheral blood mononuclear cells in systemic lupus erythematous patients

BACKGROUND

Systemic lupus erythematosus is a multisystemic rheumatic disease with different clinical features. Disturbance in apoptosis regulation seems to be a major factor in SLE development.

OBJECTIVE

Survivin plays a key role in mitosis and inhibiting apoptosis. A study was conducted to examine the expression level of survivin and miRNAs that affect survivin transcript levels in patients with SLE.

METHODS

We isolated peripheral blood mononuclear cells from 50 inactive SLE patients and 50 healthy controls. RNA is extracted and converted to cDNA. The quantitative real-time polymerase chain reaction is conducted to assess the expression levels of survivin total and its variants with effective miRNAs in PBMCs.

RESULTS

Expression levels of miR-34a-5p (fold change = 1.5, p++ = 0.027), and 218-5p (fold change = 1.5, p++ = 0.020) were significantly increased. While miR-150-5p (fold change = 0.56, p++ = 0.003) was significantly decreased. The mRNA expression of survivin-WT (fold change = 0.63, p++ = 0.002) was significantly downregulated in SLE patients compared to the healthy controls. Survivin total and its two major variants (survivin-2B, and survivin-ΔEx3) did not differ significantly between SLE patients and controls.

CONCLUSION

Although survivin-TS and its two variants (survivin-2B, and survivin-ΔEx3) were not differently expressed in SLE patients, survivin-WT had altered expression. Despite aberrant miRNA expression in PBMCs from SLE patients, survivin and miRNA expression were not associated with leukopenia. The pathogenesis of SLE disorder might be linked to survivin's other roles in the immune system aside from anti-apoptotic functions.

Exploring the Key Signaling Pathways and ncRNAs in Colorectal Cancer

Colorectal cancer (CRC) is the third most prevalent cancer to be diagnosed, and it has a substantial mortality rate. Despite numerous studies being conducted on CRC, it remains a significant health concern. The disease-free survival rates notably decrease as CRC progresses, emphasizing the urgency for effective diagnostic and therapeutic approaches. CRC development is caused by environmental factors, which mostly lead to the disruption of signaling pathways. Among these pathways, the Wingless/Integrated (Wnt) signaling pathway, Phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway, Mitogen-Activated Protein Kinase (MAPK) signaling pathway, Transforming Growth Factor-β (TGF-β) signaling pathway, and p53 signaling pathway are considered to be important. These signaling pathways are also regulated by non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). They have emerged as crucial regulators of gene expression in CRC by changing their expression levels. The altered expression patterns of these ncRNAs have been implicated in CRC progression and development, suggesting their potential as diagnostic and therapeutic targets. This review provides an overview of the five key signaling pathways and regulation of ncRNAs involved in CRC pathogenesis that are studied to identify promising avenues for diagnosis and treatment strategies.

Role of microRNA in colorectal carcinoma (CRC): a narrative review

MicroRNAs (miRNAs) are short non-coding RNAs that play a critical role in regulating gene expression by binding to target messenger RNAs (mRNAs). They were first discovered around 8 years after the identification of the first miRNA in 1993, and since then, there has been a significant increase in miRNA-related research and discoveries. MiRNAs have been implicated in various biological processes, including cancer, particularly in colorectal cancer (CRC). In CRC, miRNAs act as either oncogenes or tumor suppressors, influencing essential cellular functions such as cell proliferation, apoptosis, angiogenesis, and metastasis. The dysregulation of miRNAs in CRC can arise from different factors, leading to abnormal expression levels of their target mRNAs and subsequently affecting protein production. Consequently, miRNAs may directly target oncogenes or tumor suppressor genes, thereby contributing to cancer initiation and progression. Notably, tumors often exhibit reduced expression of mature miRNAs. In CRC research, miRNAs offer potential as diagnostic biomarkers and therapeutic targets. Specific miRNA profiles could serve as non-invasive tools for early CRC detection and risk assessment. Additionally, miRNA-based therapies present a promising approach for targeted cancer treatment by modulating miRNA expression. However, challenges related to delivery systems and long-term safety must be addressed to fully harness their therapeutic potential.

Next generation sequencing uncovers multiple miRNAs associated molecular targets in gallbladder cancer patients

Gallbladder cancer (GBC) is a lethal disease with surgical resection as the only curative treatment. However, many patients are ineligible for surgery, and current adjuvant treatments exhibit limited effectiveness. Next-generation sequencing has improved our understanding of molecular pathways in cancer, sparking interest in microRNA-based gene regulation. The aim of the study is to identify dysregulated miRNAs in GBC and investigate their potential as therapeutic tools for effective and targeted treatment strategies. GBC and control tissue samples were sequenced for miRNA expression using the Illumina HiSeq platform. Biological processes and related pathways were determined using the Panther and Gene Ontology databases. 439 significantly differentially expressed miRNAs were identified; 19 of them were upregulated and 29 were downregulated. Key enriched biological processes included immune cell apoptosis, endoplasmic reticulum (ER) overload response, and negative regulation of the androgen receptor (AR) signaling pathway. Panther analysis revealed the insulin-like growth factor (IGF)-mitogen activated protein kinases (MAPK) cascade, p38 MAPK pathway, p53 pathway, and FAS (a subgroup of the tumor necrosis factor receptor) signaling pathway as highly enriched among dysregulated miRNAs. Kirsten rat sarcoma virus (KRAS), AR, and interferon gamma (IFN-γ) pathways were identified among the key pathways potentially amenable to targeted therapy. We concluded that a combination approach involving miRNA-based interventions could enhance therapeutic outcomes. Our research emphasizes the importance of precision medicine, targeting pathways using sense and anti-sense miRNAs as potential therapies in GBC.

MiR-34 by targeting p53 induces apoptosis and DNA damage in paclitaxel-resistant human oral squamous carcinoma cells

MicroRNA-34 (miR-34) is one the most important tumor suppressor miRNAs involving in the various aspects of oral cancer. The present study aimed to evaluate the effects of miR-34 restoration in OECM-1 oral cancer resistant to paclitaxel (OECM-1/PTX) and its underlying mechanisms through p53-mediated DNA damage and apoptosis. OECM-1 and OECM-1/PTX were transfected with miR-34 mimic and inhibitor. Cellular proliferation and apoptosis were evaluated through MTT assay and flow cytometry, respectively. The mRNA and protein expression levels of p53, p-glycoprotein (P-gp), ATM, ATR, CHK1, and CHK2 were assessed through qRT-PCR and western blotting. Rhodamin123 uptake assay was used to measure the P-gp activities. P53 expression was also suppressed by sing a siRNA transfection of cells. The expression levels of miR-34 were downregulated in OECM-1/PTX. Restoration of miR-34 led to increase in cytotoxic effects of paclitaxel in cells. In addition, the expression levels and activities of P-gp were reduced following miR-34 transfection. miR-34 transfection upregulated the p53, ATM, ATR, CHK1, and CHK2 expression levels in OECM-1/PTX cells. Furthermore, cells transfected with miR-34 showed higher levels of apoptosis. miR-34 restoration reverses paclitaxel resistance in OECM-1 oral cancer. The chemosensitive effects of miR-34 is mediated through increasing DNA damage and apoptosis in a p53 depended manner.

miR-16-5p enhances sensitivity to RG7388 through targeting PPM1D expression (WIP1) in Childhood Acute Lymphoblastic Leukemia

Aim: Given the encouraging results of the p53-Mdm2 inhibitor RG7388 in clinical trials and the vital function of miR-16-5p in suppressing cell proliferation, the aim of the present study was to investigate the combined impact of RG7388 and miR-16-5p overexpression on the childhood acute lymphoblastic leukemia (chALL). Methods: miRTarBase and miRDB, along with KEGG and STRING databases, were used to predict miR-16-5p target genes and explore protein-protein interaction networks, respectively. B- and T-lymphoblastic cell lines, in addition to patient primary cells, were treated with RG7388. Ectopic overexpression of miR-16-5p in Nalm6 cell line was induced through cell electroporation and transfection of microRNA mimics was confirmed by qRT-PCR. Cell viability was evaluated using the MTT assay. Western blot analyses were performed to evaluate the effects of RG7388 and miR-16-5p upregulation on the protein levels of p53 and its downstream target genes in chALL cells. Paired sample t-test was employed for statistical analyses. Results: MTT assay showed RG7388-induced cytotoxicity in wild-type p53 Nalm6 cell line and p53 functional patient primary cells. However, CCRF-CEM and p53 non-functional leukemic cells indicated drug resistance. Western blot analyses validated the bioinformatics results, confirming the downregulation of WIP1, p53 stabilization, as well as overexpression of p21^WAF1 and Mdm2 proteins in Nalm6 cells transfected with miR-16-5p. Moreover, enhanced sensitivity to RG7388 was observed in the transfected cells. Conclusion: This is the first study indicating the mechanistic importance of miR-16-5p overexpression in chALL and its inhibitory role in leukemia treatment when combined with the p53-Mdm2 antagonist, RG7388. These findings might be useful for researchers and clinicians to pave the way for better management of chALL.

Pro-Apoptotic Activity of the Marine Sponge Dactylospongia elegans Metabolites Pelorol and 5-epi-Ilimaquinone on Human 501Mel Melanoma Cells

The natural environment represents an important source of drugs that originates from the terrestrial and, in minority, marine organisms. Indeed, the marine environment represents a largely untapped source in the process of drug discovery. Among all marine organisms, sponges with algae represent the richest source of compounds showing anticancer activity. In this study, the two secondary metabolites pelorol (PEL) and 5-epi-ilimaquinone (EPI), purified from Dactylospongia elegans were investigated for their anti-melanoma activity. PEL and EPI induced cell growth repression of 501Mel melanoma cells in a concentration- and time-dependent manner. A cell cycle block in the G1 phase by PEL and EPI was also observed. Furthermore, PEL and EPI induced significant accumulation of DNA histone fragments in the cytoplasmic fraction, indicating a pro-apoptotic effect of both compounds. At the molecular level, PEL and EPI induced apoptosis through the increase in pro-apoptotic BAX expression, confirmed by the decrease in its silencing miR-214-3p and the decrease in the anti-apoptotic BCL-2, MCL1, and BIRC-5 mRNA expression, attested by the increase in their silencing miRNAs, i.e., miR-193a-3p and miR-16-5p. In conclusion, our data indicate that PEL and EPI exert cytotoxicity activity against 501Mel melanoma cells promoting apoptotic signaling and inducing changes in miRNA expression and their downstream effectors. For these reasons could represent promising lead compounds in the anti-melanoma drug research.

From inflammatory bowel disease to colorectal cancer: what's the role of miRNAs?

Inflammatory Bowel Disease (IBD) is a chronic inflammatory disease with relapse and remission periods. Ulcerative colitis and Crohn's disease are two major forms of the disease. IBD imposes a lot of sufferings on the patient and has many consequences; however, the most important is the increased risk of colorectal cancer, especially in patients with Ulcerative colitis. This risk is increased with increasing the duration of disease, thus preventing the progression of IBD to cancer is very important. Therefore, it is necessary to know the details of events contributed to the progression of IBD to cancer. In recent years, the importance of miRNAs as small molecules with 20-22 nucleotides has been recognized in pathophysiology of many diseases, in which IBD and colorectal cancer have not been excluded. As a result, the effectiveness of these small molecules as therapeutic target is hopefully confirmed. This paper has reviewed the related studies and findings about the role of miRNAs in the course of events that promote the progression of IBD to colorectal carcinoma, as well as a review about the effectiveness of some of these miRNAs as therapeutic targets.

Dysregulation of Survivin-Targeting microRNAs in Autoimmune Diseases: New Perspectives for Novel Therapies

It has been well established that the etiopathogenesis of diverse autoimmune diseases is rooted in the autoreactive immune cells' excessively proliferative state and impaired apoptotic machinery. Survivin is an anti-apoptotic and mitotic factor that has sparked a considerable research interest in this field. Survivin overexpression has been shown to contribute significantly to the development of autoimmune diseases via autoreactive immune cell overproliferation and apoptotic dysregulation. Several microRNAs (miRNAs/miRs) have been discovered to be involved in survivin regulation, rendering the survivin-miRNA axis a perspective target for autoimmune disease therapy. In this review, we discuss the role of survivin as an immune regulator and a highly implicated protein in the pathogenesis of autoimmune diseases, the significance of survivin-targeting miRNAs in autoimmunity, and the feasibility of targeting the survivin-miRNA axis as a promising therapeutic option for autoimmune diseases.

Circulating miRNA expression over the course of colorectal cancer treatment

Colorectal cancer (CRC) is the third-most common cancer type in males and the second-most common cancer type in females, and has the second-highest overall mortality rate worldwide. Approximately 50% of patients in stage I–III develop metastases, mostly localized to the liver. All physiological conditions occurring in the organism are also reflected in the levels of circulating microRNAs (miRNAs/miRs) in patients. miRNAs are a class of small, non-coding, single-stranded RNAs consisting of 18–25 nucleotides, which have important roles in various cellular processes. The aim of the present study was to evaluate a panel of seven circulating miRNAs (miR-106a-5p, miR-210-5p, miR-155-5p, miR-21-5p, miR-103a-3p, miR-191-5p and miR-16-5p) as biomarkers for monitoring patients undergoing adjuvant treatment of CRC. Total RNA was extracted from the plasma of patients with CRC prior to surgery, in the early post-operative period (n=60) and 3 months after surgery (n=14). The levels of the selected circulating miRNAs were measured with the miRCURY LNA miRNA PCR system and fold changes were calculated using the standard ∆∆Cq method. DIANA-miRPath analysis was used to evaluate the role of significantly deregulated miRNAs. The results indicated significant upregulation of miR-155-5p, miR-21-5p and miR-191-5p, and downregulation of miR-16-5p directly after the surgery. In paired follow-up samples, the most significant upregulation was detected for miR-106a-5p and miR-16-5p, and the most significant downregulation was for miR-21-5p. Pathway analysis outlined the role of the differentially expressed miRNAs in cancer development, but the same pathways are also involved in wound healing and regeneration of intestinal epithelium. It may be suggested that these processes should also be considered in studies investigating sensitive and easily detectable circulating biomarkers for recurrence in patients.

Circulating exosomal miRNAs and cancer early diagnosis

Microribonucleic acids (miRNAs) are small non-coding ribonucleic acids (ncRNAs), which can affect recognition of homologous sequences and interfere with transcription. It plays key roles in the initiation, development, resistance, metastasis or recurrence of cancers. Identifying circulatory indicators will positively improve the prognosis and quality of life of patients with early cancer. Previous studies have shown that miRNA is highly involved in cancer. In addition, miRNA derived from cancers can be encapsulated as exosomes and further extracted into circulatory systems to realize malignant functions. It indicates that circulating exosome-derived miRNAs have the potential to replace conventional biomarkers as cancer derived exosomes carrying miRNAs can be identified by specific markers and might be more stable and accurate for early diagnosis.

Epigenetic Alterations Upstream and Downstream of p53 Signaling in Colorectal Carcinoma

Colorectal cancer (CRC) belongs to the most common tumor types, and half of all CRC harbor missense mutations in the TP53 tumor suppressor gene. In addition to genetically caused loss of function of p53, epigenetic alterations (DNA methylation, histone modifications, micro-RNAs) contribute to CRC development. In this review, we focused on epigenetic alterations related to the entire p53 signaling pathway upstream and downstream of p53. Methylation of genes which activate p53 function has been reported, and methylation of APC and MGMT was associated with increased mutation rates of TP53. The micro-RNA 34a activates TP53 and was methylated in CRC. Proteins that regulate TP53 DNA methylation, mutations, and acetylation of TP53-related histones were methylated in CRC. P53 regulates the activity of numerous downstream proteins. Even if TP53 is not mutated, the function of wildtype p53 may be compromised if corresponding downstream genes are epigenetically inactivated. Thus, the role of p53 for CRC development, therapy response, and survival prognosis of patients may be much more eminent than previously estimated. Therefore, we propose that novel diagnostic devices measuring the entirety of genetic and epigenetic changes in the "p53 signalome" have the potential to improve the predictive and prognostic power in CRC diagnostics and management.

Portrait of Cancer Stem Cells on Colorectal Cancer: Molecular Biomarkers, Signaling Pathways and miRNAome

Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and about 20% is metastatic at diagnosis and untreatable. Increasing evidence suggests that the heterogeneous nature of CRC is related to colorectal cancer stem cells (CCSCs), a small cells population with stemness behaviors and responsible for tumor progression, recurrence, and therapy resistance. Growing knowledge of stem cells (SCs) biology has rapidly improved uncovering the molecular mechanisms and possible crosstalk/feedback loops between signaling pathways that directly influence intestinal homeostasis and tumorigenesis. The generation of CCSCs is probably connected to genetic changes in members of signaling pathways, which control self-renewal and pluripotency in SCs and then establish function and phenotype of CCSCs. Particularly, various deregulated CCSC-related miRNAs have been reported to modulate stemness features, controlling CCSCs functions such as regulation of cell cycle genes expression, epithelial-mesenchymal transition, metastasization, and drug-resistance mechanisms. Primarily, CCSC-related miRNAs work by regulating mainly signal pathways known to be involved in CCSCs biology. This review intends to summarize the epigenetic findings linked to miRNAome in the maintenance and regulation of CCSCs, including their relationships with different signaling pathways, which should help to identify specific diagnostic, prognostic, and predictive biomarkers for CRC, but also develop innovative CCSCs-targeted therapies.

Tumor Suppressor Protein p53 and Inhibitor of Apoptosis Proteins in Colorectal Cancer-A Promising Signaling Network for Therapeutic Interventions

Simple Summary

Tumor suppressor 53 (p53) is a multifunctional protein that regulates cell cycle, DNA repair, apoptosis and metabolic pathways. In colorectal cancer (CRC), mutations of the gene occur in 60% of patients and are associated with a more aggressive tumor phenotype and resistance to anti-cancer therapy. In addition, inhibitor of apoptosis (IAP) proteins are distinguished biomarkers overexpressed in CRC that impact on a diverse set of signaling pathways associated with the regulation of apoptosis/autophagy, cell migration, cell cycle and DNA damage response. As these mechanisms are further firmly controlled by p53, a transcriptional and post-translational regulation of IAPs by p53 is expected to occur in cancer cells. Here, we aim to review the molecular regulatory mechanisms between IAPs and p53 and discuss the therapeutic potential of targeting their interrelationship by multimodal treatment options.

Abstract

Despite recent advances in the treatment of colorectal cancer (CRC), patient’s individual response and clinical follow-up vary considerably with tumor intrinsic factors to contribute to an enhanced malignancy and therapy resistance. Among these markers, upregulation of members of the inhibitor of apoptosis protein (IAP) family effects on tumorigenesis and radiation- and chemo-resistance by multiple pathways, covering a hampered induction of apoptosis/autophagy, regulation of cell cycle progression and DNA damage response. These mechanisms are tightly controlled by the tumor suppressor p53 and thus transcriptional and post-translational regulation of IAPs by p53 is expected to occur in malignant cells. By this, cellular IAP1/2, X-linked IAP, Survivin, BRUCE and LIVIN expression/activity, as well as their intracellular localization is controlled by p53 in a direct or indirect manner via modulating a multitude of mechanisms. These cover, among others, transcriptional repression and the signal transducer and activator of transcription (STAT)3 pathway. In addition, p53 mutations contribute to deregulated IAP expression and resistance to therapy. This review aims at highlighting the mechanistic and clinical importance of IAP regulation by p53 in CRC and describing potential therapeutic strategies based on this interrelationship.

5-aminolevulinic-acid-mediated sonodynamic therapy improves the prognosis of melanoma by inhibiting survivin expression

BACKGROUND

This study aimed to evaluate the relationship between survivin expression and melanoma after 5-aminolevulinic acid (5-ALA)-mediated sonodynamic therapy.

METHODS

Immunohistochemistry was used to detect survivin protein expression in human melanoma clinical samples. Subsequently, the effects of 5-ALA-mediated sonodynamic therapy were determined by measuring the volume of melanoma xenografts and the bodyweights of melanoma-bearing nude mice. The MTT assay was used to detect the viability of melanoma B16-F10 cells under the action of 5-ALA-mediated sonodynamic therapy, and Western blotting and PCR were used to detect survivin expression in melanoma cells and in the melanoma-xenograft model.

RESULTS

Survivin expression was significantly upregulated in human melanoma tissues compared with that of non-melanoma tissues. In the in vivo case, 5-ALA-mediated sonodynamic therapy significantly delayed tumor growth, prolonged the survival of mice, and inhibited the expression of survivin. In the in vitro case, 5-ALA-mediated sonodynamic therapy inhibited B16-F10 cell proliferation and decreased survivin expression at both protein and mRNA levels.

CONCLUSION

Our results suggest that 5-ALA-mediated sonodynamic therapy inhibited B16-F10 cell proliferation and melanoma-xenograft growth and prolonged survival of melanoma-bearing nude mice, which might be through downregulation of survivin expression.

In silico analysis of the association of hsa-miR-16 expression and cell survival in MDA-MB-231 breast cancer cells subjected to photodynamic therapy

BACKGROUND

Breast cancer is the most common malignancy effecting women, and the triple-negative breast cancer (TNBC) subtype is particularly aggressive. This study aimed to evaluate the differential expression pattern of microRNAs (miRNAs) between untreated MDA-MB-231 cells (TNBC cell model) and those that survived photodynamic therapy (PDT) to gain insights into cell survival mechanisms.

METHODS

Two PDT cycles were applied to MDA-MB-231 cells, using δ-aminolevulinic acid (ALA) followed by laser light at 635 nm. RNA was obtained from cells surviving PDT and untreated cells. The miRNAs expression profile was analyzed to detect the differences between the two groups. The potential target network of hsa-miR-16 was examined in silico with the integrative database Ingenuity® Pathway Analysis software.

RESULTS

After the first and second PDT cycles, 17.8% and 49.6% of the MDA-MB-231 cells were viable. Microarray profiling of miRNAs showed decreased hsa-miR-16 expression (p < 0.05) in MDA-MB-231 cells surviving PDT when compared to the control cells. The predicted downstream targets of hsa-miR-16 were: 1) tumor suppressor protein 53; 2) molecules related to the cell cycle, such as cyclin D1, D3, and E1, and checkpoint kinase 1; 3) cell proliferation molecules, including fibroblast growth factor 1, 2 and 7 and fibroblast growth factor receptor 1; and 4) apoptosis-related molecules, consisting of BCL-2, B-cell leukemia/lymphoma 2, caspase 3, and cytochrome c.

CONCLUSIONS

The differential expression of hsa-miR-16 between untreated MDA-MB-231 cells and those surviving PDT has not been previously reported. There was a lower expression of hsa-miR-16 in treated cells, which probably altered its downstream target network. In silico analysis predicted, a network related to the cell cycle, proliferation and apoptosis. These results are congruent with previous descriptions of hsa-miR-16 as a tumor suppressor and suggest that the treated population has increased their capacity to survive.

The P53/microRNA network: A potential tumor suppressor with a role in anticancer therapy

MicroRNAs (miRNAs) are endogenous and small non-coding RNAs that have been identified as mediators of tumor suppression as well as stress responses mediated by p53 suppressors. MiRNAs may act as tumor suppressors under certain conditions. MiRNAs regulated by p53 may control the expression of processes such as cell cycle progression, cell survival, and angiogenesis. P53 activity and expression are also controlled by miRNA; consequently alterations in the p53-miRNA network may be essential for tumor initiation and progression. Future studies on the p53-miRNA network presumably would find it helpful in diagnostic and therapeutic approaches or as tools for various cancers.

Association of the Expression Level of miR-16 with Prognosis of Solid Cancer Patients: A Meta-Analysis and Bioinformatic Analysis

Objective

To assess the association between the expression level of miR-16 and prognosis of solid cancer patients by meta-analysis and bioinformatic analysis.

Methods

PubMed, Web of Science, and Embase databases were searched until October 31, 2019, to identify eligible studies reporting the association of the miR-16 status with the prognosis of solid cancer patients. Hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled, and a heterogeneity test was conducted. Sensitivity analysis and a publication bias test were also carried out. Furthermore, the miRpower database was used to validate the association.

Results

Thirteen articles with 2303 solid cancer patients were included in the meta-analysis. Solid cancer patients with low expression level of miR-16 had shorter survival time (I² = 84.0%, HR = 1.47, 95% CI: 1.13-1.91, P = 0.004). In the subgroup analyses of cancer sites, low miR-16 expression level was associated with poor prognosis in the reproductive system cancers (I² = 33.3%, HR = 1.24, 95% CI: 1.06-1.45, P = 0.008). Sensitivity analysis suggested that the pooled HR was stable and omitting a single study did not change the significance of the pooled HR. Begg's test and Egger's test revealed no publication bias in the meta-analysis. In bioinformatic analysis, the significant association between miR-16 level and prognosis of patients with reproductive system cancers was further confirmed (HR = 1.21, 95% CI: 1.03-1.42, P = 0.017).

Conclusion

Low expression level of miR-16 is an indicator for poor prognosis of solid cancer patients, particularly in reproductive system cancers.

The roles of miRNAs' clinical efficiencies in the colorectal cancer pathobiology: A review article

MiRNAs (microRNAs) are defined as micro directors and regulators of gene expression. Since altered miRNA expression is signified in the pathobiology of diverse cancers such as colorectal cancers (CRCs), these molecules are described as therapeutic targets, either. Manipulation of miRNAs could lead to further therapy for chemo and radio-resistant CRCs. The usage of microRNAs has indicated prominent promise in the prognosis and diagnosis of CRC, because of their unique expression pattern associated with cancer types and malignancies. Nowadays, many researchers are analyzing the correlation between miRNA polymorphisms and cancer risk. With continuous incompatibility in colorectal cancer (CRC) miRNAs expression data, it is critical to move toward the content of a "pre-laboratory" analysis to speed up efficient accuracy medicine and translational study. Pathway study for the highest expressed miRNAs- regulated target genes resulted in the identification of a considerable number of genes associated with CRC pathway including PI3K, TGFβ, and APC. In this review, we aimed to collect fruitful information about miRNAs and their potential roles in CRC, and provide a meta-analysis of the most frequently studied miRNAs in association with the disease.

miRNA Clusters with Down-Regulated Expression in Human Colorectal Cancer and Their Regulation

Regulation of microRNA (miRNA) expression has been extensively studied with respect to colorectal cancer (CRC), since CRC is one of the leading causes of cancer mortality worldwide. Transcriptional control of miRNAs creating clusters can be, to some extent, estimated from cluster position on a chromosome. Levels of miRNAs are also controlled by miRNAs "sponging" by long non-coding RNAs (ncRNAs). Both types of miRNA regulation strongly influence their function. We focused on clusters of miRNAs found to be down-regulated in CRC, containing miR-1, let-7, miR-15, miR-16, miR-99, miR-100, miR-125, miR-133, miR-143, miR-145, miR-192, miR-194, miR-195, miR-206, miR-215, miR-302, miR-367 and miR-497 and analysed their genome position, regulation and functions. Only evidence provided with the use of CRC in vivo and/or in vitro models was taken into consideration. Comprehensive research revealed that down-regulated miRNA clusters in CRC are mostly located in a gene intron and, in a majority of cases, miRNA clusters possess cluster-specific transcriptional regulation. For all selected clusters, regulation mediated by long ncRNA was experimentally demonstrated in CRC, at least in one cluster member. Oncostatic functions were predominantly linked with the reviewed miRNAs, and their high expression was usually associated with better survival. These findings implicate the potential of down-regulated clusters in CRC to become promising multi-targets for therapeutic manipulation.

MicroRNA-16 inhibits the growth and metastasis of human glioma cells via modulation of PI3K/AKT/mTOR signalling pathway

Introduction

Gliomas are lethal cancers accounting for significant human mortality across the globe. MicroRNAs (miRs) have shown potential to act as therapeutic targets for the treatment of cancer. Herein the role and therapeutic implications of miR-16 in glioma were investigated.

Material and methods

Expression analysis was carried out by qRT-PCR. Cell-Titer-Glo assay (Promega) was used for the determination of cell proliferation. DAPI, AO/EB, and annexin V/PI assays were used to detect apoptosis. Wound healing and Transwell assays were used for cell migration and invasion, respectively. Western blot analysis was used for the determination of protein expression.

Results

The study revealed that miR-16 was significantly suppressed in the human glioma cells. Ectopic expression of miR-16 in U118 MG cells inhibited the proliferation via induction of apoptosis. The apoptosis induction was also accompanied by an upsurge of Bax and depletion of Bcl-2. The overexpression of miR-16 also inhibited the migration and invasion of the glioma U118 MG cells, as evident from the wound healing and transwell assays, which were accompanied by the inhibition of metalloproteinase-2 and -9 (MMP-2 and MMP-9). The effects of miR-16 overexpression were also examined on the PI3K/AKT/mTOR signalling pathway. The results showed that miR-16 overexpression inhibited the phosphorylation of the p70S6K, AKT, and mTOR at Ser473, Ser2448, and Thr389, respectively, with no apparent effects on the total PI3K and AKT.

Conclusions

miR-16 acts as tumour suppressor in glioma and may severe as therapeutic target for glioma treatment.

MicroRNA-139-5p inhibits cell viability, migration and invasion and suppresses tumor growth by targeting HDGF in non-small cell lung cancer

MicroRNA (miRNAs) serve key roles in the progress of various types of cancer. The expression of miRNA (miR)-139-5p is downregulated in several types of tumor and has been recognized as a tumor suppressor. However, the role of miR-139-5p in non-small cell lung cancer (NSCLC) has not been investigated in detail. In the present study, it was demonstrated that miR-139-5p was significantly downregulated in NSCLC cells and tissues, and the overexpression of miR-139-5p in vitro induced apoptosis and significantly inhibited the viability and proliferation of A549 and H1299 cells. In addition, upregulation of miR-139-5p significantly inhibited the migration and invasion of A549 and H1299 cells. Hepatoma-derived growth factor (HDGF) was identified as a direct target of miR-139-5p. Rescue experiments demonstrated that the inhibitory function of miR-139-5p on cell viability, migration and invasion was partially mediated by suppressing HDGF expression. Furthermore, miR-139-5p exhibited efficient inhibition of tumor growth in a xenograft tumor mouse model of A549 cells. In summary, the results from the present study suggested that miR-139-5p may serve an important role in NSCLC by targeting HDGF and causing inhibition of cell viability and metastasis, as well as induction of apoptosis. miR-139-5p may also have the potential to serve as a therapeutic target for the treatment of NSCLC.

Deregulation of cancer-stem-cell-associated miRNAs in tissues and sera of colorectal cancer patients

Colorectal cancer (CRC) is a deadly tumour in Western countries characterized by high cellular/molecular heterogeneity. Cancer stem cells (CSC) act in cancer recurrence, drug-resistance and in metastatic epithelial-to-mesenchymal transition. microRNAs (miRNAs) contribute to cancer is increasing, and miRNA roles in CSC phenotype and fate and their utility as CRC biomarkers have also been reported. Here, we investigated miR-21, miR-221, miR-18a, miR-210, miR-31, miR-34a, miR-10b and miR-16 expression in experimental ALDH⁺ and CD44⁺/CD326⁺ colorectal CSCs obtained from the human CRC cell lines HCT-116, HT-29 and T-84. Then, we moved our analysis in cancer tissue (CT), healthy tissue (HT) and serum (S) of adult CRC patients (n=12), determining relationships with clinical parameters (age, sex, metastasis, biochemical serum markers). Specific miRNA patterns were evident in vitro (normal, monolayers and CSCs) and in patients’ samples stratified by TNM stage (LOW vs HIGH) or metastasis (Met vs no-Met). miR-21, miR-210, miR-34a upregulation ad miR-16 dowregulation associated with the CSCs phenotype. miR-31b robustly overexpressed in monolayers and CSCs, and in CT ad S of HIGH grade and Met patients, suggesting a role as marker of CRC progression and metastasis. miR-18a upregulated in all cancer models and associated to CSC phenotype, and to metastasis and age in patients. miR-10b downregulated in CT and S of LOW/HIGH grade and no-Met patients. Our results identify miRNAs useful as colorectal CSC biomarker and that miR-21, miR-210, miR-10b and miR-31b are promising markers of CRC. A specific role of miR-18a as metastatic CRC serum biomarker in adult patients was also highlighted.

Long non-coding RNA SNHG12 promotes proliferation and invasion of colorectal cancer cells by acting as a molecular sponge of microRNA-16

Long non-coding (lnc)RNA small nucleolar RNA host gene 12 (SNHG12) has an oncogenic role in various common human cancer types, including colorectal cancer (CRC). However, the detailed regulatory mechanisms of SNHG12 in CRC cells have remained largely elusive, and the investigation thereof was the purpose of the present study. Polymerase chain reaction analysis was performed to examine the expression of lncRNA and microRNA (miR). Cell Counting Kit-8 and Transwell assays were used to assess cell proliferation and invasion. A luciferase reporter assay was performed to confirm a predicted targeting association between lncRNA and miR. It was observed that SNHG12 was markedly upregulated in CRC tissues when compared with that in adjacent non-tumour tissues, and its high expression was associated with CRC progression, as well as poor prognosis of patients. In addition, the expression of SNHG12 was higher in CRC cell lines when compared with that in a normal intestinal epithelial cell line. Knockdown of SNHG12 significantly inhibited CRC cell proliferation and invasion, while ectopic overexpression of SNHG12 had the opposite effect. A Bioinformatics analysis predicted that SNHG12 and miR-16 have complementary binding sites, which was confirmed by a luciferase reporter gene assay. The expression levels of miR-16 were markedly decreased in CRC tissues and cell lines compared with those in normal tissues or cells, and were inversely correlated with the expression levels of SNHG12 in CRC tissues. Furthermore, silencing of miR-16 eliminated the suppressive effects of SNHG12 knockdown on CRC cell proliferation and invasion. In conclusion, the present study demonstrated that SNHG12 promotes CRC cell proliferation and invasion, at least in part, by acting as a molecular sponge of miR-16, suggesting that SNHG12 may be a promising therapeutic target for CRC.

Epigenetic-based therapy for colorectal cancer: Prospect and involved mechanisms

Epigenetic modifications are heritable variations in gene expression not encoded by the DNA sequence. According to reports, a large number of studies have been performed to characterize epigenetic modification during normal development and also in cancer. Epigenetics can be regarded more widely to contain all of the changes in expression of genes that make by adjusted interactions between the regulatory portions of DNA or messenger RNAs that lead to indirect variation in the DNA sequence. In the last decade, epigenetic modification importance in colorectal cancer (CRC) pathogenesis was demonstrated powerfully. Although developments in CRC therapy have been made in the last years, much work is required as it remains the second leading cause of cancer death. Nowadays, epigenetic programs and genetic change have pivotal roles in the CRC incidence as well as progression. While our knowledge about epigenetic mechanism in CRC is not comprehensive, selective histone modifications and resultant chromatin conformation together with DNA methylation most likely regulate CRC pathogenesis that involved genes expression. Undoubtedly, the advanced understanding of epigenetic-based gene expression regulation in the CRC is essential to make epigenetic drugs for CRC therapy. The major aim of this review is to deliver a summary of valuable results that represent evidence of principle for epigenetic-based therapeutic approaches employment in CRC with a focus on the advantages of epigenetic-based therapy in the inhibition of the CRC metastasis and proliferation.

High microRNA-28-5p expression in colorectal adenocarcinoma predicts short-term relapse of node-negative patients and poor overall survival of patients with non-metastatic disease

BACKGROUND

MicroRNAs (miRNAs) may function either as oncogenes or tumor suppressors and are heavily involved in the initiation and progression of cancer, and in metastasis of tumor cells. MicroRNA-28-5p (miR-28-5p) targets several cancer-related genes and is hence involved in cell proliferation, migration, invasion and epithelial-mesenchymal transition. In this study, we investigated the potential diagnostic and prognostic significance of miR-28-5p expression in colorectal adenocarcinoma, the most frequent type of colorectal cancer (CRC).

METHODS

Therefore, we isolated total RNA from 182 colorectal adenocarcinoma specimens and 86 paired non-cancerous colorectal mucosae. After polyadenylation of 2 μg total RNA and its reverse transcription using an oligo-dT-adapter primer, we quantified miR-28-5p levels using an in-house-developed reverse-transcription real-time quantitative polymerase chain reaction (RT-qPCR) method, based on the SYBR Green chemistry.

RESULTS

Comparison of miR-28-5p levels among 86 pairs of colorectal tumors and their adjacent non-cancerous mucosae uncovered the downregulation of miR-28-5p expression in the majority of malignant colorectal tumors. More importantly, high miR-28-5p expression predicts poor disease-free survival (DFS) and overall survival (OS) of colorectal adenocarcinoma patients. Multivariate Cox regression analysis revealed that miR-28-5p overexpression is a significant predictor of poor prognosis in colorectal adenocarcinoma, independent of tumor size, histological grade, TNM staging, radiotherapy and chemotherapy. Interestingly, strong miR-28-5p expression retains its predictive potential regarding relapse among patients with negative regional lymph nodes, and predicts poor OS in patients diagnosed with non-metastatic colorectal adenocarcinoma.

CONCLUSIONS

High miR-28-5p expression predicts poor DFS and OS of colorectal adenocarcinoma patients, independently of clinicopathological prognosticators and standard patient treatment, including radiotherapy and chemotherapy.

Different signatures of miR-16, miR-30b and miR-93 in exosomes from breast cancer and DCIS patients

Loading of microRNAs (miRNAs) into exosomes that are involved in cellular communication is a selective process. The current study investigates whether the enrichment of miRNAs in exosomes reflects the pathogenesis of breast cancer (BC) and ductal carcinoma in situ (DCIS). The levels of miRNAs were quantified in exosomes from plasma of 32 BC patients, 8 DCIS patients and 8 healthy women by TaqMan real-time PCR-based miRNA array cards containing 47 different miRNAs. Then, exosomal miR-16, miR-30b and miR-93 that displayed deregulation in the arrays were selected and analyzed in 111 BC patients, 42 DCIS patients and 39 healthy women by TaqMan real-time PCR. Identification of exosomes was performed by Western blot. The levels of exosomal miR-16 were higher in plasma of BC (p = 0.034) and DCIS (p = 0.047) patients than healthy women, and were associated with estrogen (p = 0.004) and progesterone (p = 0.008) receptor status. Particularly, in estrogen-positive patients miR-16 was significantly enriched in exosomes (p = 0.0001). Lower levels of exosomal miR-30b were associated with recurrence (p = 0.034). Exosomal miR-93 was upregulated in DCIS patients (p = 0.001). Our findings suggest that different signatures of miR-16, miR-30b and miR-93 in exosomes from BC and DCIS patients are associated with a particular biology of breast tumors.

MicroRNA-16 functions as a tumor-suppressor gene in oral squamous cell carcinoma by targeting AKT3 and BCL2L2

Aberrant expressions of microRNAs have been reported to be strongly associated with the progression and prognosis of various tumors, including oral squamous cell carcinoma (OSCC). Recent studies on miRNA expression profiling have suggested that microRNA-16 (miR-16) may be dysregulated in OSCC. However, the tumorigenic roles and mechanisms of miR-16 in OSCC are still largely unknown. In this study, we demonstrated that miR-16 was specifically downregulated in both OSCC patients and cancer cell lines. In addition, functional roles of miR-16 in vitro suggested that the miR-16 mimic inhibited cell proliferation and induced apoptosis, whereas miR-16 inhibitor displayed the opposite effects. Luciferase reporter assay and correlation analysis showed that AKT3 and BCL2L2 were directly targeted by miR-16 and were inversely expressed with miR-16 in OSCC. Moreover, restoration of AKT3 and BCL2L2 expression could partially reverse the cell proliferation inhibition and apoptosis induction caused by miR-16. In xenograft nude mice, miR-16 mimics decreased the expression of AKT3 and BCL2L2 and reduced the tumors volumes and weights, whereas the miR-16 inhibitor exhibited adverse effects in the derived xenografts. In conclusion, the findings suggested that miR-16 functions as a tumor suppressor miRNA to inhibit cell proliferation and induce apoptosis in OSCC through decreasing the oncogenes AKT3 and BCL2L2 and that miR-16 could be a potential therapeutic target for OSCC.

Tumour suppressor properties of miR-15a and its regulatory effects on BCL2 and SOX2 proteins in colorectal carcinomas

OBJECTIVES

In this study, we aimed to investigate the expression pattern, clinicopathological significance and tumour suppressive properties of miR-15a in patients with colorectal carcinomas.

METHODS

Tissue samples from 87 patients with primary colorectal carcinomas, 50 matched metastatic lymph node and 37 non-neoplastic colon (control) were prospectively recruited. The expression level of miR-15a was measured by quantitative real-time polymerase chain reaction. Restoration/overexpression of the miR-15a was achieved by exogenous transfection. Four colon cancer cell lines (SW480, CaCO2, SW48 and HCT116) and a non-cancer colon cell line (FHC) were also used for examining the miR-15a induced tumour suppression properties using various in-vitro and immunological assays.

RESULTS

Downregulation of miR-15a was noted in ~ 62% of the colorectal carcinoma tissues and it was positively correlated with the presence of cancer recurrence in patients with colorectal carcinomas (p = 0.05). Also, these patients with low miR-15a expression showed relatively shorter survival time when compared to those with miR-15a overexpression. Following miR-15a exogenous overexpression, colon cancer cells showed reduced cell proliferation, low colony formation, less cell invasion properties and mitochondrial respiration when compared to control cells. In addition, BCL2 and SOX2 proteins showed a significant downregulation following miR-15a overexpression suggesting its regulatory role in cancer growth, apoptosis and stemness.

CONCLUSION

This study has confirmed the tumour suppressor properties of miR-15a in colorectal cancers. Therefore, its modulation has potential implications in controlling various biological and pathogenic processes in colon carcinogenesis via targeting its downstream proteins such as BCL2 and SOX2.

mRNA-miRNA bipartite network reconstruction to predict prognostic module biomarkers in colorectal cancer stage differentiation

Biomarker detection is one of the most important and challenging problems in cancer studies. Recently, non-coding RNA based biomarkers such as miRNA expression levels have been used for early diagnosis of many cancer types. In this study, a systems biology approach was used to detect novel miRNA based biomarkers for CRC diagnosis in early stages. The mRNA expression data from three CRC stages (Low-grade Intraepithelial Neoplasia (LIN), High-grade Intraepithelial Neoplasia (HIN) and Adenocarcinoma) were used to reconstruct co-expression networks. The networks were clustered to extract co-expression modules and detected low preserved modules among CRC stages. Then, the experimentally validated mRNA-miRNA interaction data were applied to reconstruct three mRNA-miRNA bipartite networks. Twenty miRNAs with the highest degree (hub miRNAs) were selected in each bipartite network to reconstruct three bipartite subnetworks for further analysis. The analysis of these hub miRNAs in the bipartite subnetworks revealed 30 distinct important miRNAs as prognostic markers in CRC stages. There are two novel CRC related miRNAs (hsa-miR-190a-3p and hsa-miR-1277-5p) in these 30 hub miRNAs that have not been previously reported in CRC. Furthermore, a drug-gene interaction network was reconstructed to detect potential candidate drugs for CRC treatment. Our analysis shows that the hub miRNAs in the mRNA-miRNA bipartite network are very essential in CRC progression and should be investigated precisely in future studies. In addition, there are many important target genes in the results that may be critical in CRC progression and can be analyzed as therapeutic targets in future research.

Omega-3 fatty acid DHA modulates p53, survivin, and microRNA-16-1 expression in KRAS-mutant colorectal cancer stem-like cells

Background

The presence of chemotherapy-resistant colorectal cancer stem cells (CCSCs) with KRAS mutation is thought to be one of the primary causes for treatment failure in colorectal cancer (CRC). P53, survivin, and microRNA-16-1 are challenging targets for anticancer drugs which are associated with chemoresistance in CRC. Yet, no p53-, survivin-, and microRNA-16-1-modulating drug with low toxicity but high efficacy against KRAS-mutant CCSCs have been approved for clinical application in CRC. Here, we investigated whether in vitro concentrations of DHA equal to human plasma levels, are able to modulate, Wt-p53, survivin, and microRNA-16-1 in CRC cells with stem cell-like properties.

Methods

Wt-p53/KRAS-mutant CRC cells (HCT-116) with stem cell-like properties were treated with 100-, 150- and 200-μM/L DHA, after which cell number, viability, growth inhibition, Wt-p53, survivin and microRNA-16-1 expression, caspase-3 activation and apoptotic-rate were evaluated by different cellular and molecular techniques.

Results

After 24-, 48-, and 72-h treatments with 100- to 200-μM/L DHA, growth inhibition- rates were measured to be 54.7% to 59.7%, 73.% to 75.8%, and 63.3% to 97.7%, respectively. Treatment for 48 h with indicated DHA concentrations decreased cell number and viability. In addition, we observed a decrease in both the transcript and protein levels of survivin followed by 1.3- to 1.7- and 1.1- to 4.7-fold increases in the Wt-p53 accumulation and caspase-3 activation levels respectively. Treatment with 100 and 150 μM/L DHA increased microRNA-16-1 expression levels by 1.3- to 1.7-fold and enhanced the microRNA-16-1/survivin mRNA, p53/survivin, and caspase-3/survivin protein ratios by 1.7- to 1.8-, 1.3- to 2.6-, and 1.3- to 2-fold increases respectively. A decrease in the number of live cells and an increase in the number of apoptotic cells were also observed with increasing DHA concentrations.

Conclusion

Wt-p53, survivin, and microRNA-16-1 appear to be promising molecular targets of DHA. Thus, DHA might represent an attractive anti-tumor agent directed against KRAS-mutant CCSCs.

Potential roles of microRNAs and ROS in colorectal cancer: diagnostic biomarkers and therapeutic targets

As one of the most commonly diagnosed cancers worldwide, colorectal adenocarcinoma often occurs sporadically in individuals aged 50 or above and there is an increase among younger patients under 50. Routine screenings are recommended for this age group to improve early detection. The multifactorial etiology of colorectal cancer consists of both genetic and epigenetic factors. Recently, studies have shown that the development and progression of colorectal cancer can be attributed to aberrant expression of microRNA. Reactive oxygen species (ROS) that play a key role in cancer cell survival, can also lead to carcinogenesis and cancer exacerbations. Given the rapid accumulating knowledge in the field, an updated review regarding microRNA and ROS in colorectal cancer is necessary. An extensive literature search has been conducted in PubMed/Medline databases to review the roles of microRNAs and ROS in colorectal cancer. Unique microRNA expression in tumor tissue, peripheral blood, and fecal samples from patients with colorectal cancer is outlined. Therapeutic approaches focusing on microRNA and ROS in colorectal cancer treatment is also delineated. This review aims to summarize the newest knowledge on the pathogenesis of colorectal cancer in the hopes of discovering novel diagnostic biomarkers and therapeutic techniques.

Effect of Taoren Quyu Decoction on human endometrial cells and its anti-endometriosis activity in rats

OBJECTIVE

To study the effect of Taoren Quyu Decoction (TQD) on endometrial cells in patients with endometriosis (EMs) and EMs in rats.

METHODS

A total of 60 female Wistar rats were randomly divided into 4 groups, namely, normal group, model group, positive group and TQD group, each group having 15 rats. Except the normal group, EMs model was established in the other three groups by transplanting the rat autologous endometrium. After 4 weeks of intragastric administration, blood, eutopic and ectopic endometrial tissues of rats in each group were collected to detect the serum levels of estrogen (E2), cancer antigen 125 (CA125), endometrial antibody (EMAb), and expressions of microvessel density (MVD), vascular endothelial growth factor (VEGF) and angiopoietin (Ang-2). The volume of endometriosis cyst was determined simultaneously. For the in vitro culture of human endometrial cells, 4 groups, namely, normal group, model group, positive group and TQD group were used. The positive group and TQD group were treated with danazol and TQD respectively. Then 24 h after the treatment, the expressions of survivin and tumor suppressor gene (p53) of each group were detected.

RESULTS

The volumes of the endometriosis cysts in the positive group and the TQD group were significantly reduced compared with the model group (P < 0.05). The serum levels of E2, CA125 and EMAb, and the expressions of MVD, VEGF and Ang-2 in the model group were significantly increased compared with the normal group (P < 0.05); while they were all significantly reduced in the positive group and TQD group (P < 0.05). Compared with the normal group, the expression of survivin in the model group was significantly up-regulated (P < 0.05), and expression of p53 was significantly reduced (P < 0.05); compared with the model group, the expressions of survivin in the positive and TQD groups were significantly decreased (P < 0.05), and expression of p53 was significantly up-regulated (P < 0.05). The difference between positive group and TQD group was not statistically significant (P > 0.05).

CONCLUSIONS

TQD has a significant anti-EMs effect, and its mechanism of action may be related to anti-angiogenesis and promoting apoptosis of ectopic endometrial cell.

Non-coding RNAs Enabling Prognostic Stratification and Prediction of Therapeutic Response in Colorectal Cancer Patients

Colorectal cancer (CRC) is a heterogeneous disease and current treatment options for patients are associated with a wide range of outcomes and tumor responses. Although the traditional TNM staging system continues to serve as a crucial tool for estimating CRC prognosis and for stratification of treatment choices and long-term survival, it remains limited as it relies on macroscopic features and cases of surgical resection, fails to incorporate new molecular data and information, and cannot perfectly predict the variety of outcomes and responses to treatment associated with tumors of the same stage. Although additional histopathologic features have recently been applied in order to better classify individual tumors, the future might incorporate the use of novel molecular and genetic markers in order to maximize therapeutic outcome and to provide accurate prognosis. Such novel biomarkers, in addition to individual patient tumor phenotyping and other validated genetic markers, could facilitate the prediction of risk of progression in CRC patients and help assess overall survival. Recent findings point to the emerging role of non-protein-coding regions of the genome in their contribution to the progression of cancer and tumor formation. Two major subclasses of non-coding RNAs (ncRNAs), microRNAs and long non-coding RNAs, are often dysregulated in CRC and have demonstrated their diagnostic and prognostic potential as biomarkers. These ncRNAs are promising molecular classifiers and could assist in the stratification of patients into appropriate risk groups to guide therapeutic decisions and their expression patterns could help determine prognosis and predict therapeutic options in CRC.

miR-34a overexpression predicts poor prognostic outcome in colorectal adenocarcinoma, independently of clinicopathological factors with established prognostic value

OBJECTIVES

MicroRNA-34a (miR-34a) is regulated by TP53 and, in response, downregulates the expression of a gamut of protein-coding genes, including apoptosis regulators, transcription factors, cyclins, and cyclin-dependent kinases. Its upregulation initiates a reprogramming of gene expression and promotes apoptosis. The purpose of this study was the investigation of the potential clinical significance of miR-34a as a molecular prognostic biomarker in colorectal adenocarcinoma using an in-house real-time quantitative PCR (qPCR) methodology.

DESIGN AND METHODS

Total RNA was extracted from 113 primary colorectal adenocarcinoma specimens and 61 paired non-cancerous colorectal tissue samples. After polyadenylation and reverse transcription, miR-34a molecules were determined using qPCR based on SYBR Green chemistry. Calculations were performed using the comparative C_T method. Finally, extensive biostatistical analysis was performed.

RESULTS

miR-34a expression does not significantly differ between colorectal adenocarcinoma tissue specimens and adjacent non-cancerous mucosae. However, miR-34a expression increases progressively as colorectal adenocarcinoma loses its differentiation, being highest in grade III tumors (P=0.010). Moreover, miR-34a expression is a potential unfavorable prognostic biomarker in colorectal adenocarcinoma, predicting poor disease-free and overall survival (P=0.002 and P=0.019, respectively), independently of classical clinicopathological parameters. Most importantly, miR-34a expression stratifies patients without local (N0) and/or distant metastasis (M0) at the time of diagnosis into two groups with substantially different prognosis (P=0.013 and P=0.002, respectively).

CONCLUSIONS

High miR-34a levels in colorectal adenocarcinoma predict a rather increased risk for disease recurrence and poor overall survival, particularly in patients at an early TNM stage. The unfavorable prognostic potential of miR-34a expression is independent of established prognostic features of colorectal adenocarcinoma.

Upregulated miR-16 expression is an independent indicator of relapse and poor overall survival of colorectal adenocarcinoma patients

BACKGROUND

Colorectal adenocarcinoma is one of the most common malignant tumors of the gastrointestinal tract and the second leading cause of cancer-related deaths among adults in Western countries. miR-16 is heavily involved in cancer progression. In this study, we examined the potential diagnostic and prognostic utility of miR-16 expression in colorectal adenocarcinoma.

METHODS

Total RNA was extracted from 182 colorectal adenocarcinoma specimens and 86 non-cancerous colorectal mucosae. After polyadenylation of 2 μg total RNA by poly(A) polymerase and subsequent reverse transcription with an oligo-dT adapter primer, miR-16 expression was determined using an in-house developed reverse transcription quantitative real-time PCR method, based on SYBR Green chemistry. SNORD43 (RNU43) and SNORD48 (RNU48) were used as reference genes. Next, we performed extensive biostatistical analysis.

RESULTS

miR-16 was shown to be significantly upregulated in colorectal adenocarcinoma specimens compared to non-cancerous colorectal mucosae, suggesting its potential exploitation for diagnostic purposes. Moreover, high miR-16 expression predicts poor disease-free survival (DFS) and overall survival (OS) of colorectal adenocarcinoma patients. Multivariate Cox regression analysis confirmed that miR-16 overexpression is a significant unfavorable prognosticator in colorectal adenocarcinoma, independent of other established prognostic factors, radiotherapy, and chemotherapy. Interestingly, miR-16 overexpression retains its unfavorable prognostic value in patients with advanced yet locally restricted colorectal adenocarcinoma that has not grown through the wall of the colon or rectum (T3) and in those without distant metastasis (M0).

CONCLUSIONS

Overexpression of the cancer-associated miR-16 predicts poor DFS and OS of colorectal adenocarcinoma patients, independently of clinicopathological factors that are currently used for prognostic purposes.

Deregulation of the miR-16-KRAS axis promotes colorectal cancer

KRAS plays a significant role in the etiology and progression of colorectal cancer (CRC), but the mechanism underlying this process has not been fully elucidated. In this study, we found that the KRAS protein levels were higher in CRC tissues than in the normal adjacent tissues, whereas its mRNA levels varied irregularly, suggesting that a post-transcriptional mechanism is involved in the regulation of KRAS. Then, we performed bioinformatic analyses to search for miRNAs that potentially target KRAS. We predicted and experimentally validated that miR-16 directly recognizes the 3'-UTR of the KRAS transcript and regulates KRAS expression. Furthermore, the in vitro results showed that the repression of KRAS by miR-16 suppressed the proliferation and invasion and induced the apoptosis of CRC cells, and the in vivo results revealed that miR-16 exerted a tumor-suppressive effect by negatively regulating KRAS in xenograft mice. Taken together, our findings provide evidence supporting the role of miR-16 as a tumor suppressor in CRC by targeting KRAS.

Mechanism analysis of colorectal cancer according to the microRNA expression profile

The present study aimed to identify specific microRNAs (miRs) and their predicted target genes to clarify the molecular mechanisms of colorectal cancer (CRC). An miR expression profile (array ID, GSE39833), which consisted of 88 CRC samples with various tumor-necrosis-metastasis stages and 11 healthy controls, was downloaded from the Gene Expression Omnibus database. Subsequently, the differentially expressed miRs and their target genes were screened. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways of target genes were analyzed using the Database for Annotation Visualization and Integrated Discovery. A protein-protein interaction (PPI) network of the target genes was constructed using the Search Tool for the Retrieval of Interacting Genes database. The present study identified a total of 18 differentially expressed miRs (upregulated, 8; downregulated, 10) in the sera of the CRC patients compared with the healthy controls. Of these, 3 upregulated (let-7b, miR-1290 and miR-126) and 2 downregulated (miR-16 and miR-760) differentially expressed miRs and their target genes, including cyclin D1 (CCND1), v-myc avian myelocytomatosis viral oncogene homolog (MYC), phosphoinositide-3-kinase, regulatory subunit 2 (beta) (PIK3R2) and SMAD family member 3 (SMAD3), were significantly enriched in the CRC developmental pathway. All these target genes had higher node degrees in the PPI network. In conclusion, let-7b, miR-1290, miR-126, miR-16 and miR-760 and their target genes, CCND1, MYC, PIK3R2 and SMAD3, may be important in the molecular mechanisms for the progression of CRC.

Colorectal tumor molecular phenotype and miRNA: expression profiles and prognosis

MiRNAs regulate gene expression by post-transcriptionally suppressing mRNA translation or by causing mRNA degradation. It has been proposed that unique miRNAs influence specific tumor molecular phenotype. In this paper, we test the hypotheses that miRNA expression differs by tumor molecular phenotype and that those differences may influence prognosis. Data come from population-based studies of colorectal cancer conducted in Utah and the Northern California Kaiser Permanente Medical Care Program. A total of 1893 carcinoma samples were run on the Agilent Human miRNA Microarray V19.0 containing 2006 miRNAs. We assessed differences in miRNA expression between TP53-mutated and non-mutated, KRAS-mutated and non-mutated, BRAF-mutated and non-mutated, CpG island methylator phenotype (CIMP) high and CIMP low, and microsatellite instability (MSI) and microsatellite stable (MSS) colon and rectal tumors. Using a Cox proportional hazard model we evaluated if those miRNAs differentially expressed by tumor phenotype influenced survival after adjusting for age, sex, and AJCC stage. There were 22 differentially expressed miRNAs for TP53-mutated colon tumors and 5 for TP53-mutated rectal tumors with a fold change of >1.49 (or <0.67). Additionally, 13 miRNAS were differentially expressed for KRAS-mutated rectal tumors, 8 differentially expressed miRNAs for colon CIMP high tumors, and 2 differentially expressed miRNAs for BRAF-mutated colon tumors. The majority of differentially expressed miRNAS were observed between MSI and MSS tumors (94 differentially expressed miRNAs for colon; 41 differentially expressed miRNAs for rectal tumors). Of these miRNAs differentially expressed between MSI and MSS tumors, the majority were downregulated. Ten of the differentially expressed miRNAs were associated with survival; after adjustment for MSI status, five miRNAS, miR-196b-5p, miR-31-5p, miR-99b-5p, miR-636, and miR-192-3p, were significantly associated with survival. In summary, it appears that the majority of miRNAs that are differentially expressed by tumor molecular phenotype are MSI tumors. However, these miRNAs appear to have minimal effect on prognosis.

miRNA-15a/16: as tumor suppressors and more

Since their first discovery in chronic lymphocytic leukemia, miR-15a and miR-16 have been reported to act as tumor suppressors or potential oncomiRs in different types of cancer. This review summarizes the history, biological properties and the important functions of these two miRNAs in cancer. It also introduces their roles as regulators of immune responses and angiogenesis, endogenous controls as well as potential targets and hallmarks of cancer.

Development of a deregulating microRNA panel for the detection of early relapse in postoperative colorectal cancer patients

Background

Colorectal cancer (CRC) is the third leading cause of cancer mortality worldwide and is associated with high recurrence and mortality, despite recent advancements in therapeutic strategies. MicroRNA (miR) deregulation is associated with CRC development and recurrence; therefore, miRs may be reliable biomarkers for detecting early relapse postoperatively.

Methods

In this study ten candidates were identified using miR arrays: miR-7, miR-31, miR-93, miR-141, miR-195, miR-375, miR-429, miR-494, miR-650, and let-7b. Substantial differences were observed in their expression levels between early relapsed (recurrences within 12 months after surgery) and non-early relapsed CRC patients. The validation study, including 50 early relapsed and 54 non-early relapsed patients, confirmed miR expression alterations in cancer tissue samples.

Results

Using a miR real-time quantitative polymerase chain reaction (RT-qPCR), we observed that expression levels of miR-93, miR-195, and let-7b were significantly decreased, whereas those of miR-7, miR-141 and miR-494 showed increases that were more significant in the CRC tissue samples from the early relapsed patients than in those from the non-early relapsed patients. Disease-free survival and overall survival were significantly worse in the high miR-7, miR-141, and miR-494 expression subgroups and the low miR-93 and miR-195 expression subgroups (all P < 0.05). A panel of 6 miRs (miR-7, miR-93, miR-195, miR-141, miR-494, and let-7b), at a cut-off value of 2 deregulated miRs, distinguished early relapsed CRC from non-early relapsed CRC, with a sensitivity of 76.6 % and a specificity of 71.4 %. By combining this 6-miRs panel with 6 clinicopathologic factors, at a cut-off value of 4, distinguished early relapsed CRC from non-early relapsed CRC, with a sensitivity of 89.4 % and a specificity of 88.9 %.

Conclusions

This study showed that the developed miR panel has the potential to improve predicting early relapse in CRC patients.

Effective Targeting Survivin, Caspase-3 and MicroRNA-16-1 Expression by Methyl-3-pentyl-6-methoxyprodigiosene Triggers Apoptosis in Colorectal Cancer Stem-Like Cells

Over-expression of the proto-oncogene survivin in colorectal cancer stem cells (CCSCs) is thought to be one the primary causes for therapy failure. It has also been reported that tumor suppressor miR-16-1 is down-regulated in colorectal cancer (CRC) cells. Therefore, the search for new anti-proliferative agents which target survivin or miR-16-1 in CCSCs is warranted. Several studies have shown that prodigiosin isolated from cell wall of Serratia marcescens induces apoptosis in different kinds of cancer cells. Here, we investigated the effects of prodigiosin on HCT-116 cells that serve as a model for CRC initiating cells with stem-like cells properties. HCT-116 cells were treated with 100, 200 and 400 nM prodigiosin after which cell number, viability, growth-rate, survivin and miRNA-16-1 expression, caspase-3 activation and apoptotic rate were evaluated. Prodigiosin decreased significantly growth-rate in a dose-and time-dependent manner. After a 48 h treatment with 100, 200 and 400 nM prodigiosin, growth-rates were measured to be 84.4 ± 9.2 %, 58 ± 6.5 % and 46.3 ± 5.2 %, respectively, compared to untreated cells. We also found that treatment for 48 h with indicated concentrations of prodigiosin resulted in 41 %, 54.5 % and 63 % decrease in survivin mRNA levels and induced 32 %, 48 % and 61 % decrease in survivin protein levels as well as resulted in 128.3 ± 10 %, 178.7 ± 6.1 % and 205 ± 7.6 % increase in caspase-3 activation respectively compared to untreated cells. Prodigiosin caused a significant increase in miRNA-16-1 expression at a concentration of 100 nM and treatment with different concentrations of prodigiosin resulted in 2.2- to 3-fold increase in miRNA-16-1/survivin ratios compared to untreated cells. An increase in number of apoptotic cells ranging from 28.2 % to 86.8 % was also observed with increasing prodigiosin concentrations. Our results provide the first evidence that survivin and miRNA-16-1 as potential biomarkers could be targeted in CRC initiating cells with stem-like cells properties by prodigiosin and this compound with high pro-apoptotic capacity represents the possibility of its therapeutic application directed against CCSCs.

High miR-96 levels in colorectal adenocarcinoma predict poor prognosis, particularly in patients without distant metastasis at the time of initial diagnosis

MicroRNA-96 (miR-96) is an oncomiR that facilitates the development of malignant tumors by promoting growth, proliferation, and survival of cancer cells. Previous studies using high-throughput techniques have shown that miR-96 is upregulated in colorectal cancer compared to adjacent normal colorectal tissue. The aim of this study was the investigation of the potential clinical value of miR-96 as a molecular prognostic biomarker in colorectal adenocarcinoma. For this purpose, total RNA was extracted from 108 primary colorectal adenocarcinoma samples and 54 paired non-cancerous colorectal tissue specimens. After polyadenylation and reverse transcription, miR-96 molecules were determined using an in-house developed real-time quantitative PCR based on SYBR Green chemistry. Calculations were carried out with the comparative C_T method, using SNORD48 as endogenous reference gene. Finally, extensive biostatistical analysis was performed and showed that miR-96 is significantly upregulated in colorectal adenocarcinoma specimens compared to their non-cancerous counterparts (p < 0.001) as well as in tumors having invaded regional lymph nodes (p = 0.009) and those of advanced TNM stage (p = 0.008). miR-96 expression is an unfavorable prognostic marker in colorectal adenocarcinoma, predicting poor disease-free and overall survival (p = 0.041 and 0.028, respectively), independently of classical clinicopathological parameters. Most importantly, miR-96 expression stratifies patients without distant metastasis (M0) at the time of diagnosis into two groups with substantially different prognosis (p = 0.040). In conclusion, high tissue levels of miR-96 are associated with advanced stages of colorectal adenocarcinoma and predict an increased risk for disease recurrence and poor overall survival, especially in patients without distant metastasis at the time of diagnosis.

MicroRNAs in colorectal carcinoma--from pathogenesis to therapy

Background

Acting as inflammatory mediators, tumor oncogenes or suppressors, microRNAs are involved in cell survival, death, epithelial–mesenchymal transition and metastasis, etc. Investigating the communication between microRNAs and tumorigenesis is critical to our understanding of the pathogenesis of multiple disease states.

Main body

Currently, colorectal carcinoma (CRC), one of the most common malignancies worldwide, has a poor prognosis due to lack of an effective therapeutic option. Increasing evidence has identified altered profiles and regulatory potential of microRNAs in conditions related to environmentally-caused colorectal inflammation and colitis-associated cancer. Many studies have shed light on a more thorough understanding of the function and distribution of microRNAs in CRC initiation and emergence. However, the molecular mechanisms by which microRNAs modulate cellular processes still need to be further elucidated and may offer a foundation for evaluating microRNA-based therapeutic potential for CRC in both animal models and clinical trials.

Conclusion

In this review, the roles and mechanisms of microRNAs involved in CRC from pathogenesis to therapy are summarized and discussed, which may provide more useful hints for CRC prevention and therapy.

Polymorphisms in pre-miRNA genes and cooking oil fume exposure as well as their interaction on the risk of lung cancer in a Chinese nonsmoking female population

BACKGROUND

MicroRNAs (miRNAs) are suggested to be very important in the development of lung cancer. This study assesses the association between polymorphisms in miRNA-related (miR)-26a-1, miR-605, and miR-16-1 genes and risk of lung cancer, as well as the effect of gene-environment interaction between miRNA polymorphisms and cooking fume exposure on lung cancer.

METHODS

A case-control study including 268 diagnosed nonsmoking female lung cancer patients and 266 nonsmoking female controls was carried out. Three miRNA polymorphisms (miR-26a-1 rs7372209, miR-605 rs2043556, and miR-16-1 rs1022960) were analyzed. Both additive and multiplicative interactions were assessed.

RESULTS

MiR-16-1 rs1022960 may be associated with the risk of lung cancer. Carriers with TT genotype of miR-16-1 rs1022960 were observed to have a decreased risk of lung cancer compared with CC and CT genotype carriers (odds ratio =0.550, 95% confidence interval =0.308-0.983, P=0.044). MiR-26a-1 rs7372209 and miR-605 rs2043556 showed no statistically significant associations with lung cancer risk. There were no significant associations between the three single nucleotide polymorphisms and lung adenocarcinoma. People with exposure to both risk genotypes of miR-26a-1 rs7372209 and cooking oil fumes were more likely to develop lung cancer than those with only genetic risk factor or cooking oil fumes (odds ratios were 2.136, 1.255, and 1.730, respectively). The measures of biological interaction and logistic models indicate that gene-environment interactions were not statistically significant on additive scale or multiplicative scale.

CONCLUSION

MiR-16-1 rs1022960 may be associated with the risk of lung cancer in a Chinese nonsmoking female population. The interactions between miRNA polymorphisms (miR-26a-1 rs7372209, miR-605 rs2043556, and miR-16-1 rs1022960) and cooking oil fumes were not statistically significant.

A systematic investigation based on microRNA-mediated gene regulatory network reveals that dysregulation of microRNA-19a/Cyclin D1 axis confers an oncogenic potential and a worse prognosis in human hepatocellular carcinoma

MicroRNAs (miRNAs) contribute to a wide variety of human diseases by regulating gene expression, leading to imbalances in gene regulatory networks. To discover novel hepatocellular carcinoma (HCC)-related miRNA-target axes and to elucidate their functions, we here performed a systematic investigation combining biological data acquisition and integration, miRNA-target prediction, network construction, functional assay and clinical validation. As a result, a total of 117 HCC differentially expressed miRNAs were identified, and 728 high confident target genes of these miRNAs were collected. Then, the interaction network of target genes was constructed and 221 key nodes with topological importance in the network were identified according to their topological features including degree, node-betweenness, closeness and K-coreness. Among these key nodes, Cyclin D1 had the highest node-betweenness, implying its bottleneck role in the network. Luciferase reporter assay confirmed that miRNA-19a, which was one of HCC downregulated miRNAs, directly targeted Cyclin D1 in HCC cells. Moreover, miR-19a might play inhibitory roles in HCC malignancy via regulating Cyclin D1 expression. Further clinical evidence also highlighted the prognostic potential of miR-19a/Cyclin D1 axis in HCC. In conclusion, this systematic investigation provides a framework to identify featured miRNAs and their target genes which are potent effectors in the occurrence and development of HCC. More importantly, miR-19a/Cyclin D1 axis might have promising applications as a therapeutic target and a prognostic marker for patients with HCC.

MicroRNA-mRNA interactions in colorectal cancer and their role in tumor progression

MicroRNAs (miRNA/miR) play an important role in gene regulatory networks through targeting mRNAs. They are involved in diverse biological processes such as cell proliferation, differentiation, angiogenesis, and apoptosis. Due to their pivotal effects on multiple genes and pathways, dysregulated miRNAs have been reported to be associated with different diseases, including colorectal cancer (CRC). Recent evidence indicates that aberrant miRNA expression is tightly linked with the initiation and progression of CRC. To elucidate the influence of miRNA regulation in CRC, it is critical to identify dysregulated miRNAs, their target mRNA genes and their involvement in gene regulatory and signaling networks. Various experimental and computational studies have been conducted to decipher the function of miRNAs involved in CRC. Experimental studies that are used for this purpose can be classified into two categories: direct/individual and indirect/high-throughput gene expression studies. Here we review miRNA target identification studies related to CRC with an emphasis on experimental data based on Luciferase reporter assays. Recent advances in determining the function of miRNAs and the signaling pathways they are involved in have also been summarized. The review helps bioinformaticians and biologists to find extensive information about downstream targets of dysregulated miRNAs, and their pro-/anti-CRC effects.