The roles of miR-200c in colon cancer and associated molecular mechanisms. Tumour Biol. 2014;35:6475-6483. [PMID: 24682933 DOI: 10.1007/s13277-014-1860-x]

The usefulness of evaluating PTEN expression for accurate grading of phyllodes tumors

Phyllodes tumors (PTs) are classified as benign, borderline, or malignant based on histologic characteristics. However, because histological criteria are subjective and diagnosis requires integrating multiple findings, discrepancies often occur between observers. Therefore, it is necessary to discover biomarkers based on the molecular characteristics of PTs. This study aimed to identify dysregulated microRNAs (miRNAs) in PTs through miRNA profiling and determine whether expression of their target genes could be useful as PT biomarkers. MiRNA profiling was performed on 13 PTs (three malignant, three borderline, seven benign) and six fibroadenomas, and predicted target genes of dysregulated miRNAs were selected using three computation algorithms. The expression of two miRNAs, miR-155 and miR-200c, was 1.69-fold and 1.61-fold higher, respectively, in borderline and malignant PT groups than in the benign PT group (p < 0.05). KEGG pathway analysis revealed that the 374 target genes of these two miRNAs (miR-155 and miR200c) participated in several signaling pathways, adherens junction, cell cycle, and pathway in cancer. Immunohistochemical staining for PTEN, one of candidate target genes of miR-200c, was performed on whole slides of PT tissue classified as malignant (n = 9), borderline (n = 12), or benign (n = 21). Stromal tumor cells of high-grade PTs (borderline and malignant) had significantly lower PTEN expression than those of low-grade PTs (benign) (p-value ≤0.001). Semiquantitative analysis of PTEN expression, score 0-8, revealed that it correlated with histologic findings. Low PTEN expression (s-score of 6 or less) was used as a diagnostic criterion for high-grade PTs, it showed 100 % sensitivity and 95.2 % specificity in 42 cases of PTs. Currently, PT grading based solely on subjective histologic findings is challenging, but semiquantitative PTEN expression analysis could provide a more accurate and objective way to grade PTs.

Diagnostic performances of methylated septin9 gene, CEA, CA19-9 and platelet-to-lymphocyte ratio in colorectal cancer

BACKGROUND

This study was designed to compare the diagnostic efficacy of mSEPT9 to four blood markers (CEA, CA19-9, platelet-lymphocyte ratio (PLR) and neutrophil-lymphocyte ratio (NLR)). In addition, we aimed to determine the combined diagnostic efficacy of mSEPT9, CEA, CA19-9, PLR and NLR in colorectal cancer.

METHODS

A total of 567 participants were enrolled in the study, including 308 CRC patients, 61 colorectal polyp patients and 198 healthy subjects confirmed by colonoscopy and/or tissue biopsy. Plasma samples were collected for tests.

RESULTS

The positive rate of mSEPT9 in CRC (71.8%) was markedly higher than that in either the colorectal polyps group (27.9%) or the healthy controls (6.1%) (P < 0.001). The levels of CEA, CA19-9, NLR and PLR in the CRC group were significantly higher than those in the non-CRC groups (P < 0.05). ROC curves comparison analyses showed that the diagnostic efficacy of mSEPT9 alone in CRC was significantly higher than CEA, CA19-9, NLR and PLR alone. The combination of mSEPT9 with CEA, CA19-9 and PLR showed superior diagnostic value. In addition, binary logistic regression was also used to build a better model for clinical diagnosis of CRC. On univariable analyses, age, mSEPT9, CEA, CA 19-9, PLR and NLR were independent predictors of CRC. When these covariates were fitted in multivariable models, the ones with positive detection of mSEPT9, CEA, CA 19-9 and PLR were more likely to have CRC.

CONCLUSIONS

This research revealed a significant association between mSEPT9 status and the clinicopathological characteristics of CRC patients, and the combination of mSEPT9, CEA, CA19-9 and PLR could significantly improve diagnostic efficacy in CRC.

Non-coding RNA-related antitumor mechanisms of marine-derived agents

In the last two decades, natural active substances have attracted great attention in developing new antitumor drugs, especially in the marine environment. A series of marine-derived compounds or derivatives with potential antitumor effects have been discovered and developed, but their mechanisms of action are not well understood. Emerging studies have found that several tumor-related signaling pathways and molecules are involved in the antitumor mechanisms of marine-derived agents, including noncoding RNAs (ncRNAs). In this review, we provide an update on the regulation of marine-derived agents associated with ncRNAs on tumor cell proliferation, apoptosis, cell cycle, invasion, migration, drug sensitivity and resistance. Herein, we also describe recent advances in marine food-derived ncRNAs as antitumor agents that modulate cross-species gene expression. A better understanding of the antitumor mechanisms of marine-derived agents mediated, regulated, or sourced by ncRNAs will provide new biomarkers or targets for potential antitumor drugs from preclinical discovery and development to clinical application.

Differential Expression of Decorin in Metastasising Colorectal Carcinoma Is Regulated by miR-200c and Long Non-Coding RNAs

Decorin (DCN) is one of the matricellular proteins that participate in normal cells’ function as well as in cancerogenesis. While its expression in primary tumours is well known, there is limited data about its expression in metastases. Furthermore, the post-transcriptional regulation of DCN is still questionable, although it is well accepted that it is an important mechanism of developing metastatic cancer. The aim of our study was to analyse the expression of DCN and its potential regulatory ncRNAs in metastatic colorectal carcinoma (CRC). Nineteen patients with metastatic CRC were included. Using qPCR, we analysed the expression of DCN, miR-200c and five lncRNAs (LUCAT1, MALAT1, lncTCF7, XIST, and ZFAS1) in lymph node and liver metastases in comparison to the invasive front and central part of a primary tumour. Our results showed insignificant upregulation of DCN and significant upregulation for miR-200c, MALAT1, lncTCF7 and ZFAS1 in metastases compared to the primary tumour. miR-200c showed a positive correlation with DCN, and the aforementioned lncRNAs exhibited a significant positive correlation with miR-200c expression in metastatic CRC. Our results suggest that DCN as well as miR-200c, MALAT1, lncTCF7 and ZFAS1 contribute to the development of metastases in CRC and that regulation of DCN expression in CRC by ncRNAs is accomplished in an indirect manner.

The PI3K/Akt/mTOR axis in colorectal cancer: Oncogenic alterations, non-coding RNAs, therapeutic opportunities, and the emerging role of nanoparticles

Colorectal cancer (CRC) is one of the deadliest human malignancies worldwide. Several molecular pathways have been demonstrated to be involved in the initiation and development of CRC which among them, the overactivation of the phosphatidyl-inositol 3-kinase (PI3K)/Akt/mTOR axis is of importance. The current review aims to unravel the mechanisms by which the PI3K/Akt/mTOR pathway affects CRC progression; and also, to summarize the original data obtained from international research laboratories on the oncogenic alterations and polymorphisms affecting this pathway in CRC. Besides, we provide a special focus on the regulatory role of noncoding RNAs targeting the PI3K/Akt/mTOR pathway in this malignancy. Questions on how this axis is involved in the inhibition of apoptosis, in the induction of drug resistance, and the angiogenesis, epithelial to mesenchymal transition, and metastasis are also responded. We also discussed the PI3K/Akt pathway-associated prognostic and predictive biomarkers in CRC. In addition, we provide a general overview of PI3K/Akt/mTOR pathway inhibition whether by chemical-based drugs or by natural-based medications in the context of CRC, either as monotherapy or in combination with other therapeutic agents; however, those treatments might have life-threatening side effects and toxicities. To the best of our knowledge, the current review is one of the first ones highlighting the emerging roles of nanotechnology to overcome challenges related to CRC therapy in the hope that providing a promising platform for the treatment of CRC.

Oxyresveratrol inhibits human colon cancer cell migration through regulating epithelial-mesenchymal transition and microRNA

The major cause of death in colorectal cancer (CRC) patients is metastasis. Moreover, lots of studies have emphasized that the epithelial-mesenchymal transition (EMT) is a pivotal step in metastasis. Both transforming growth factor beta (TGF-β) and dysregulation of microRNAs (miRNAs) can induce or regulate EMT, promoting the loss of intercellular adhesion and increased motility of cancer cells. Therefore, it is necessary to prevent or inhibit the metastasis of colorectal cancer. Relatively little is known about the anti-metastatic effect of oxyresveratrol (OXY), a natural derivative of resveratrol (RES), compared to RES. Accordingly, RES was used as the positive control to investigate the effects of OXY on colon cancer cell migration. The results showed that OXY could significantly inhibit cell migration (67.17% ± 0.04, 64.89% ± 0.04) compared to RES (84.6% ± 0.07, 76.34% ± 0.08) in HCT116 cells and TGF-β-induced HT-29 cells, respectively, via Snail/E-cadherin expression. In addition, OXY improved EMT-related miRNA expression through, for example, lowering the levels of miR-3687 and miR-301a-3p while upregulating miR-3612 in TGF-β-induced HT-29 cells. In conclusion, OXY inhibits human colon cancer cell migration by regulating EMT and miRNAs. Based on these findings, it can be stated that OXY promotes anti-metastatic properties in CRC.

MiR-200c promotes papillary thyroid cancer cell proliferation, migration, and invasion by downregulating PTEN

MiR-200c has been reported in several types of human cancer. Nevertheless, the expression profile and biological functions of miR-200c remain uncovered papillary thyroid cancer (PTC). The expression level of miR-200c was evaluated in PTC tissues using RT-qPCR. Survival analysis was performed in a cohort of 88 PTC patients. The effects of miR-200c on cell proliferation, migration, and invasion capacities were analyzed using CCK-8 and transwell assays. Target genes of miR-200c were assessed using luciferase reporter assay, RT-qPCR, Western blot and rescue experiments. MiR-200c was found to be upregulated in human PTC tissues and closely associated with pN stage and distant metastasis. High expression of miR-200c was associated with poor clinical prognosis in PTC patients. Whilst overexpression of miR-200c was demonstrated to promote the proliferation, migration, and invasion of PTC cells; knockdown of miR-200c showed an opposite inhibitory effect. Bioinformatics analysis and luciferase reporter assays confirmed that PTEN is a downstream target of miR-200c. Functional assays demonstrated that PTC cell proliferation, migration, and invasion were promoted by miR-200c via negative regulation of PTEN. Finally, overexpression of PTEN was shown to partially reverse the tumor promoting effect of miR-200c. In conclusion, this study indicates that miR-200c is a crucial prognostic biomarker of PTC, and that targeting of miR-200c/ PTEN axis may be of therapeutic significance in PTC patients.

The impact of microRNAs on myeloid-derived suppressor cells in cancer

Inflammation promotes cancer development. To a large extent, this can be attributed to the recruitment of myeloid-derived suppressor cells (MDSCs) to tumors. These cells are known for establishing an immunosuppressive tumor microenvironment by suppressing T cell activities. However, MDSCs also promote metastasis and angiogenesis. Critically, as small non-coding RNAs that regulate gene expression, microRNAs (miRNAs) control MDSC activities. In this review, we discuss how miRNA networks regulate key MDSC signaling pathways, how they shape MDSC development, differentiation and activation, and how this impacts tumor development. By targeting the expression of miRNAs in MDSCs, we can alter their main signaling pathways. In turn, this can compromise their ability to promote multiple hallmarks of cancer. Therefore, this may represent a new powerful strategy for cancer immunotherapy.

MiR-200c/FUT4 axis prevents the proliferation of colon cancer cells by downregulating the Wnt/β-catenin pathway

BACKGROUND

MicroRNA (miR)-200c has been widely reported to be involved in colon cancer progress. However, the mechanisms of miR-200c in regulating tumor metastasis and growth remain to be fully elucidated. This study aimed to investigate the mechanism of miR-200c targets fucosyltransferase 4 (FUT4) on the proliferation of colon cancer.

METHODS

The miR-200c and FUT4 mRNA levels in LoVo and SW480 cells were measured by real-time quantitative polymerase chain reaction. Further, miR-200c mimic, FUT4 siRNA and FUT4 mimic were transfected into cells, separately. Cell counting kit-8, plate colony formation and transwell assays were used to analyse the cells biological behaviour.. Immunofluorescence was used to analyse the Ki-67 expression Moreover, the Wnt/β-catenin pathway-related proteins were detected by western blots. A double luciferase experiment was performed to confirm the relationship between miR-200c and FUT4. In vivo, tumour growth and Wnt/β-catenin pathway-related proteins were also analysed.

RESULTS

In vitro, the expression of miR-200c and FUT4 were negatively correlated in LoVo and SW480 cells (correlation coefficients were - 0.9046 and - 0.9236, respectively). MiR-200c overexpression inhibited the proliferation, migration and invasion of LoVo and SW480 cells by downregulating FUT4. The Ki67-positive cells and Wnt/β-catenin signalling pathway-related proteins were reduced in the miR-200c overexpression and FUT4 silencing groups. A dual luciferase reporting system identified FUT4 as the target of miR-200c. The results in vivo were further confirmed the foundation of cells study.

CONCLUSIONS

In summary, miR-200c overexpression inhibits proliferation of colon cancer targeting FUT4 to downregulate the Wnt/β-catenin pathway, which promises molecular targets to inhibit metastasis for colon cancer therapy.

The potential value of miRNA-223 as a diagnostic biomarker for Egyptian colorectal patients

OBJECTIVES

Colorectal cancer (CRC) is the third lethal malignancy worldwide. Dysregulation of microRNAs (miRNAs) mediates several growth factors signaling pathways and induces abnormal genes expression, which leads to colorectal carcinogenesis. We aimed to comprehensively assess the expression of miRNA-200c, miRNA-203a, miRNA-223 in Egyptian CRC tissue and their corresponding serum samples and to explore if they have any potential prognostic or diagnostic value for CRC patients.

METHODS

A total of 195 subjects (120 CRC patients and 75 healthy controls) participated in exploration and validation sets. The relative expression of miRNA-200c, miRNA-203a, and miRNA-223 was measured in both CRC tissue and serum samples, and the expressed miRNAs were compared in different CRC grades and types and the prognostic value was evaluated.

RESULTS

The expression levels of miRNA-200c and miRNA-203a were reduced in CRC tissue samples than adjacent noncancerous tissues. miRNA-223 level was significantly upregulated in both CRC tissue and serum samples with a positive association between them (r = 0.85, P = 0.001). The miRNA-223 can effectively discriminate CRC patients from controls and can significantly differentiate between colon and rectal cancer patients. The association between serum miRNA-223 expression and CRC development was validated in the second set and the ROC curve showed highly significant prognostic value with 90.1% sensitivity, 87% specificity, and area under the curve of 0.914 (95% confidence interval: 0.830-0.978, P = 0.0001). These results showed the association between miRNA-223 upregulation and the CRC carcinogenesis.

CONCLUSION

Circulating miRNA-223 can be a potential noninvasive prognostic biomarker for Egyptian CRC patients.

MicroRNA, Diabetes Mellitus and Colorectal Cancer

Diabetes mellitus (DM) is an endocrinological disorder that is due to either the pancreas not producing enough insulin, or the body does not respond appropriately to insulin. There are many complications of DM such as retinopathy, nephropathy, and peripheral neuropathy. In addition to these complications, DM was reported to be associated with different cancers. In this review, we discuss the association between DM and colorectal cancer (CRC). CRC is the third most commonly diagnosed cancer worldwide that mostly affects older people, however, its incidence and mortality are rising among young people. We discuss the relationship between DM and CRC based on their common microRNA (miRNA) biomarkers. miRNAs are non-coding RNAs playing important functions in cell differentiation, development, regulation of cell cycle, and apoptosis. miRNAs can inhibit cell proliferation and induce apoptosis in CRC cells. miRNAs also can improve glucose tolerance and insulin sensitivity. Therefore, investigating the common miRNA biomarkers of both DM and CRC can shed a light on how these two diseases are correlated and more understanding of the link between these two diseases can help the prevention of both DM and CRC.

MicroRNA Expression and Correlation with mRNA Levels of Colorectal Cancer-Related Genes

INTRODUCTION

MicroRNAs (miRNAs), as a family of non-coding RNAs, have opened a new window in cancer biology and transcriptome. It has been revealed that miRNAs post-transcriptionally regulate the gene expression and involve in colorectal cancer (CRC) development and progression. Our aim was to examine the differential expression of miRNAs in a CRC and to correlate their expression levels with mRNA levels of CRC-related genes (K-ras, APC, p53).

MATERIALS AND METHODS

Seventy-two colorectal tumor tissues from patients with newly diagnosed CRC and 72 matched normal adjacent tissues were analyzed. Relative expression of seven CRC-related miRNAs (miR-21, miR-31, miR-20a, miR-133b, and miR-145, miR-135b and let-7g) and three CRC-related genes (K-ras, APC, p53) was detected using the SYBR Green quantitative real-time PCR technique. The correlation between gene expression levels and clinicopathological features was evaluated.

RESULTS

Our results showed a significant difference between the two groups for the expression level of miR-21, miR-31, miR-145, and miR-20a (P < 0.001). Also, a significant difference between the two groups for the expression level of K-ras was found (P < 0.001). Further analysis revealed an inverse significant correlation between miR-145 and K-ras (R² = 0.662, P < 0.001), while a positive correlation was observed between miR-21 and K-ras (R² = 0.732, P < 0.001).

CONCLUSION

Dysregulation of miRNAs and correlation with molecular signaling pathways designated a biological role for miRNAs in various cellular mechanisms underlying CRC. On the other hand, the pattern of miRNAs expression and its correlation with transcriptional status are helpful to discovery biomarkers and design therapeutics for CRC.

Transfer of metastatic traits via miR-200c in extracellular vesicles derived from colorectal cancer stem cells is inhibited by atractylenolide I

Cancer stem cells (CSCs) are important factors contributing to tumorigenesis. We examined whether CSCs isolated from colorectal cancer (CRC) cells possess metastatic properties that can be transferred to non-CSCs via the delivery of miR-200c enclosed in extracellular vesicles (EVs). The inhibitory effect of atractylenolide I (ATL-1), a traditional Chinese medicinal compound, on miR-200c activity and metastatic transfer was investigated. EVs were isolated from colorectal CSCs. The expression of miR-200c was evaluated in CSCs and CSC-derived EVs, and horizontal transfer of metastatic properties via EVs to non-CSCs was investigated in terms of cell behavior and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling. CSCs isolated from metastatic CRC cells exhibited higher levels of miR-200c than those in nonmetastatic CRC cells. Overexpression of miR-200c in CSCs enhanced metastatic potential by promoting proliferation and inhibiting apoptosis, in turn leading to the release of EVs carrying an excess of miR-200c. Non-CSCs co-cultured with miR-200c-containing EVs exhibited enhanced invasion and stemness maintenance associated with PI3K/Akt/mTOR activation, demonstrating successful metastatic transfer via EV delivery. Furthermore, ATL-1 impaired the EV-mediated transfer of metastatic properties by suppressing miR-200c activity and disrupting EV uptake by non-CSCs. EVs are critical signal transducers that facilitate intercellular communication and exchange of metastatic properties, which can be controlled by ATL-1. The findings are useful in the development of microRNA-based anticancer strategies by targeting EV-mediated activity, especially using natural compounds.

MicroRNAs and Apoptosis in Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of cancer death in the world, and its incidence is rising in developing countries. Treatment with 5-Fluorouracil (5-FU) is known to improve survival in CRC patients. Most anti-cancer therapies trigger apoptosis induction to eliminate malignant cells. However, de-regulated apoptotic signaling allows cancer cells to escape this signaling, leading to therapeutic resistance. Treatment resistance is a major challenge in the development of effective therapies. The microRNAs (miRNAs) play important roles in CRC treatment resistance and CRC progression and apoptosis. This review discusses the role of miRNAs in contributing to the promotion or inhibition of apoptosis in CRC and the role of miRNAs in modulating treatment resistance in CRC cells.

Exosomal miR-200c-3p negatively regulates the migraion and invasion of lipopolysaccharide (LPS)-stimulated colorectal cancer (CRC)

BACKGROUND

Colorectal cancer (CRC) is a leading cancer and a major cause of death. Lipopolysaccharide (LPS), an abundant component in gut microbiome, is involved in CRC progression and metastasis, potentially through regulating the miRNA composition of CRC-derived exosomes. In this study, we aimed to identify miRNA species in exosome which regulates CRC progression after LPS stimulation.

RESULTS

Firstly, we discovered a shift of miRNA profile in CRC exosome after LPS stimulation. Among the differentially expressed miRNAs, we identified miR-200c-3p as a potential key regulator of CRC progression and metastasis. Retrospective analysis revealed that miR-200c-3p was elevated in CRC tumor tissues, but decreased in the serum exosome in CRC patients. In vitro experiments demonstrated that exosomal miR-200c-3p expression did not influence CRC cell proliferation, but negatively regulated their capacity of migration and invasion in the presence of LPS. miR-200c-3p level in exosome influenced exosomal expression of Zinc finger E-box-binding homeobox-1 (ZEB-1) mRNA, one of the miR-200c targets which affects migration and invasion capacity, and further altered ZEB-1 protein expression in CRC cell. In addition, exosomal miR-200c-3p promotes apoptosis of HCT-116 cells.

CONCLUSIONS

Our findings indicate that exosomal miR-200c-3p inhibits CRC migration and invasion, and promotes their apoptosis after LPS stimulation. It is suggested as a potential diagnostic marker and therapeutic target of CRC.

Inflammation and DNA Methylation-Dependent Down-Regulation of miR-34b-5p Mediates c-MYC Expression and CRL4DCAF4 E3 Ligase Activity in Colitis-Associated Cancer

miRNAs, a well-known group of noncoding RNAs, contribute to the pathogenesis of multiple diseases, including colitis-associated cancer (CAC). Our recent findings indicate that proinflammatory cytokines up-regulate c-MYC level, which subsequently activates cullin 4A and 4B (CUL4A/4B) and CRL4^DCAF4 E3 ligases and promotes ubiquitination of suppression of tumorigenicity 7 in CAC. Herein, we identified and proved that miR-34b-5p can directly target c-MYC. In vitro oncogenic phenotype analyses and in vivo tumor formation assay indicated that miR-34b-5p overexpression could markedly decrease cell proliferation, colony formation, cell invasion, and tumor volumes. Overexpression of c-MYC in vitro could reverse the oncogenic phenotypes caused by miR-34b-5p up-regulation. In addition, the down-regulation of miR-34b-5p in CAC was dependent on the coregulation of the inflammatory microenvironment and DNA methylation. Collectively, our findings demonstrate that intracellular inflammation and DNA hypermethylation suppress miR-34b-5p expression, which limits its inhibitory effect on c-MYC and initiates the downstream events, including the induction of CRL4^DCAF4 E3 ligase activity. The activated CRL4^DCAF4 E3 ligase ubiquitinates suppression of tumorigenicity 7 and results in its degradation, eventually leading to the CAC tumorigenesis.

Role of Regulatory Oncogenic or Tumor Suppressor miRNAs of PI3K/AKT Signaling Axis in the Pathogenesis of Colorectal Cancer

Colorectal cancer (CRC) is the leading cause of cancer death worldwide and its incidence is increasing. In most patients with CRC, the PI3K/AKT signaling axis is over-activated. Regulatory oncogenic or tumor suppressor microRNAs (miRNAs) for PI3K/AKT signaling regulate cell proliferation, migration, invasion, angiogenesis, as well as resistance to chemo-/radio-therapy in colorectal cancer tumor tissues. Thus, regulatory miRNAs of PI3K/AKT/mTOR signaling represent novel biomarkers for new patient diagnosis and obtaining clinically invaluable information from post-treatment CRC patients for improving therapeutic strategies. This review summarizes the current knowledge of miRNAs' regulatory roles of PI3K/AKT signaling in CRC pathogenesis.

Epithelial-Mesenchymal Transition-Related MicroRNAs and Their Target Genes in Colorectal Cancerogenesis

MicroRNAs of the miR-200 family have been shown experimentally to regulate epithelial-mesenchymal transition (EMT). Although EMT is the postulated mechanism of development and progression of colorectal cancer (CRC), there are still limited and controversial data on expression of miR-200 family and their target genes during CRC cancerogenesis. Our study included formalin-fixed paraffin-embedded biopsy samples of 40 patients (10 adenomas and 30 cases of CRC with corresponding normal mucosa). Expression of miR-141, miR-200a/b/c and miR-429 and their target genes (CDKN1B, ONECUT2, PTPN13, RND3, SOX2, TGFB2 and ZEB2) was analysed using quantitative real-time PCR. Expression of E-cadherin was analysed using immunohistochemistry. All miRNAs were down-regulated and their target genes showed the opposite expression in CRC compared to adenoma. Down-regulation of the miR-200 family at the invasive front in comparison to the central part of tumour was observed as well as a correlation of expression of miR-200b, CDKN1B, ONECUT2 and ZEB2 expression to nodal metastases. Expression of the miR-200 family and SOX2 also correlated with E-cadherin staining. These results suggest that the miR-200 family and their target genes contribute to progression of adenoma to CRC, invasive properties and development of metastases. Our results strongly support the postulated hypotheses of partial EMT and intra-tumour heterogeneity during CRC cancerogenesis.

Circulating miR-141-3p, miR-143-3p and miR-200c-3p are differentially expressed in colorectal cancer and advanced adenomas

Colorectal cancer (CRC) is one of the prominent causes of cancer related deaths because, in part, there is not an early, non-invasive, effective detection strategy. Circulating microRNAs (miRNAs) have been proposed as potential non-invasive biomarkers for CRC. In this study, we evaluated the miRNA profile in sixteen CRC tissues by Next-Generation-Sequencing and compared the circulating expression levels of 22 miRNAs among 45 CRC, 14 hyperplastic polyps, 11 advanced adenoma patients and 45 control subjects, by reverse transcription-quantitative PCR, to search for miRNAs which could be potential biomarkers. In total, nine of them represented 70% of total read counts (miR-10a-5p, miR-192-5p, miR-10b-5p, miR-22-3p, miR-26a-5p, miR-148a-3p, miR-181a-5p, miR-92a-3p and miR-143-5p). In silico analysis found eight candidates to mature miRNAs. With respect to circulating miRNA, we found higher serum expression levels of miR-143-3p, miR-141-3p and miR-200c-3p in the CRC and adenoma groups compared with controls (P<0.002), and we also found significant higher levels of miR-141-3p and miR-200c-3p in serum of adenoma patients compared with the CRC group. In conclusion, the measurement of miRNAs in the blood could complement current screening methods for CRC and might provide new insights into mechanisms of tumorigenesis. miR-143-3p, miR-141-3p and miR-200c-3p could be interesting miRNAs to study as potential biomarkers for CRC.

Expression of miR-9 and miR-200c, ZEB1, ZEB2 and E-cadherin in Non-Small Cell Lung Cancers in Iran

MicroRNAs (miRNAs) exert a critical influence on physiological and pathological processes through post-transcriptional modification of their mRNA targets. They play important roles in tumorigenesis and are considered to be potential diagnostic and prognostic biomarkers with various cancers. MiR-200c and miR-9 are regulatory elements that can have dual impacts as oncogenes and/or tumor suppressor genes. MiR-200c regulates two transcription factors, ZEB1 and ZEB2, while miR-9 is a regulatory factor for the E-cadherin protein which has a critical function in cell-cell junctions and is inhibited by two transcription factors ZEB1 and ZEB2. In this study, expression levels of miR-200c and miR-9, ZEB-1, ZEB-2 and E-cadherin were assessed in 30 non-small cell lung cancers (NSCLCs) by real-time qPCR. MiR-9 was down-regulated significantly in tumor tissues compared to normal adjacent tissues, while there was no significant change in expression level of miR-200c. On the other hand, ZEB1 demonstrated significant increase and ZEB2a decrease at the mRNA level. These results indicate roles for miR-9 and ZEB1 in genesis of lung cancer, although clinico-pathological associations were not evident. Further studies are necessary to assess implications for treatment of lung cancer.

The Role of Extracellular Vesicles as Modulators of the Tumor Microenvironment, Metastasis and Drug Resistance in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide, with high morbidity and mortality rates. A number of factors including modulation of the tumor microenvironment, high metastatic capability, and resistance to treatment have been associated with CRC disease progression. Recent studies have documented that tumor-derived extracellular vesicles (EVs) play a significant role in intercellular communication in CRC via transfer of cargo lipids, proteins, DNA and RNAs to the recipient tumor cells. This transfer influences a number of immune-related pathways leading to activation/differentiation/expression of immune cells and modulation of the tumor microenvironment that plays a significant role in CRC progression, metastasis, and drug resistance. Furthermore, tumor-derived EVs are secreted in large amounts in biological fluids of CRC patients and as such the expression analysis of EV cargoes have been associated with prognosis or response to therapy and may be a source of therapeutic targets. This review aims to provide a comprehensive insight into the role of EVs in the modulation of the tumor microenvironment and its effects on CRC progression, metastasis, and drug resistance. On the other hand, the potential role of CRC derived EVs as a source of biomarkers of response and therapeutic targets will be discussed in detail to understand the dynamic role of EVs in CRC diagnosis, treatment, and management.

Clinical value of preoperative methylated septin 9 in Chinese colorectal cancer patients

BACKGROUND

The methylated septin 9 (mSEPT9) assay was the first blood-based test approved by the United States Food and Drug Administration as a colorectal screening test. However, the diagnostic and prognostic role of preoperative mSEPT9 for colorectal cancer (CRC) in Chinese patients is still unknown.

AIM

To improve the understanding of diagnostic and prognostic factors, serum mSEPT9 was detected in Chinese CRC patients.

METHODS

A retrospective analysis of 354 cases, of which 300 had CRC and 54 were normal, was performed in China. Patients’ characteristics, treatments, and laboratory data, including age, the date of surgery, Union for International Cancer Control (UICC) stages, distant metastasis (M), and so on, were collected. Methylation levels of SEPT9 were quantified by quantitative, methylation-specific polymerase chain reaction before surgery. In addition, the effects of mSEPT9 on the occurrence and prognosis of 330 CRC cases from The Cancer Genome Atlas (TCGA) database were evaluated using bioinformatics analyses. Potential prognostic factors for overall survival (OS) and progression-free survival (PFS) were evaluated by Kaplan-Meier univariate analysis.

RESULTS

In Chinese CRC patients, positive mSEPT9 was strongly associated with advanced UICC stages, deeper invasion by the primary tumor, and more distant metastasis. Methylation levels of SEPT9 were stage-dependent and showed a stepwise increase in UICC stages (I–IV), primary tumor categories (T1–T4), regional node categories (N0–N2), and distant metastasis categories (M0–M1). The patients with positive mSEPT9 showed a tendency toward lower PFS. After analyzing TCGA clinical data, the high mSEPT9 group was found to be obviously correlated only with more distant metastasis. The patients with high mSEPT9 levels showed a tendency toward lower OS. Besides, nine meaningful mSEPT9 sites were found to provide guidance for the follow-up studies.

CONCLUSION

MSEPT9 analysis may add valuable information to current tumor staging. Serum mSEPT9 in Chinese CRC patients appears to offer promising novel prognostic markers and might be considered for monitoring CRC recurrence.

The Significance Role of microRNA-200c as a Prognostic Factor in Various Human Solid Malignant Neoplasms: A Meta-Analysis

Objective: The aim of this study was to conduct a meta-analysis of 49 relevant studies to evaluate the prognostic value of miRNA-200c in various human malignant neoplasms.

Methods: All relevant studies were identified by searching PubMed, Embase and Web of Science until August 15^st, 2018. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) of miRNA-200c for overall survival (OS) and progression-free survival (PFS)/recurrence-free survival (RFS)/disease-free survival (DFS) were calculated to investigate such associations.

Results: Overall, 49 eligible studies were included in this meta-analysis. Our results showed that high expression of miRNA-200c was significantly correlated with a poor OS in cancer (pooled HR = 1.32, 95% CI: 1.06-1.65), but was not significantly correlated with PFS/RFS/DFS in cancer (pooled HR=1.05, 95% CI: 0.84-1.23). In our subgroup analysis, high miRNA-200c expression predicted a significantly worse OS (pooled HR = 1.50, 95% CI: 1.12-2.01) only in Caucasians. Moreover, high miRNA-200c expression even showed significantly poor OS (pooled HR = 1.88, 95% CI: 1.39-2.54) in blood samples. In addition, a significantly unfavorable OS (pooled HR = 2.69, 95% CI: 1.49-4.85) and (pooled HR = 2.66, 95% CI: 1.07-6.59) associated with up-regulated miRNA-200c expression were observed in breast cancer and endometrial cancer, respectively. Besides, high miRNA-200c expression also showed significantly poor PFS/RFS/DFS (pooled HR=1.66, 95% CI: 1.03-2.67) in breast cancer.

Conclusions: Our findings indicated that high miRNA-200c expression was a promising biomarker for patient survival and disease progression in malignant tumors, especially in breast cancer and endometrial cancer. Considering the insufficient evidence, further large-scale researches and clinical studies were needed to verify these results.

Therapeutic microRNAs in human cancer

MicroRNAs (miRNAs) are RNA molecules at about 22 nucleotide in length that are non-coding, which regulate gene expression in the post-transcriptional level by performing degradation or blocks translation of the target mRNA. It is known that they play roles in mechanisms such as metabolic regulation, embryogenesis, organogenesis, differentiation and growth control by providing post-transcriptional regulation of gene expression. With these properties, miRNAs play important roles in the regulation of biological processes such as proliferation, differentiation, apoptosis, drug resistance mechanisms in eukaryotic cells. In addition, there are miRNAs that can be used for cancer therapy. Tumor cells and tumor microenvironment have different miRNA expression profiles. Some miRNAs are known to play a role in the onset and progression of the tumor. miRNAs with oncogenic or tumor suppressive activity specific to different cancer types are still being investigated. This review summarizes the role of miRNAs in tumorigenesis, therapeutic strategies in human cancer and current studies.

The role of microRNAs involved in PI3-kinase signaling pathway in colorectal cancer

In recent decades, cancer has been one of the most important concerns of the human community, which affects human life from many different ways, such as breast, lung, colorectal, prostate, and other cancers. Colorectal cancer is one of the most commonly diagnosed cancers in the world that has recently been introduced as the third leading cause of cancer deaths in the world. microRNAs have a very crucial role in tumorgenesis and prevention of cancer, which plays a significant role with influencing various factors through different signaling pathways. Phosphoinositide 3 (PI3)-kinase/AKT is one of the most important signaling pathways involved in the control and growth of tumor in colorectal cancer, through important proteins of this pathway, such as PTEN and AKT, that they can perform specific influence on this process. Our effort in this study is to collect microRNAs that act as tumor suppressors and oncomirs in this cancer through PI3-kinase/AKT signaling pathway.

MiR-192, miR-200c and miR-17 are fibroblast-mediated inhibitors of colorectal cancer invasion

Colorectal cancer remains a leading cause of cancer-related death worldwide. A previous transcriptomics based study characterized molecular subgroups of which the stromal subgroup was associated with the worst clinical outcome. Micro-RNAs (miRNAs) are well-known regulators of gene expression and can follow a non-linear repression mechanism. We set up a model combining piecewise linear and linear regression and applied this combined regression model to a comprehensive colon adenocarcinoma dataset. We identified miRNAs involved in regulating characteristic gene sets, particularly extracellular matrix remodeling in the stromal subgroup. Comparison of expression data from separated (epithelial) cancer cells and stroma cells or fibroblasts associate these regulatory interactions with infiltrating stromal or tumor-associated fibroblasts. MiR-200c, miR-17 and miR-192 were identified as the most promising candidates regulating genes crucial for extracellular matrix remodeling. We validated our computational findings by in vitro assays. Enforced expression of either miR-200c, miR-17 or miR-192 in untransformed human colon fibroblasts down-regulated 85% of all predicted target genes. Expressing these miRNAs singly or in combination in human colon fibroblasts co-cultured with colon cancer cells considerably reduced cancer cell invasion validating these miRNAs as cancer cell infiltration suppressors in tumor associated fibroblasts.

Emerging paradigms in the treatment of liver metastases in colorectal cancer

Efforts to combat colorectal cancer have benefited from improved screening and surveillance, which facilitates early detection. The survival rate associated with diagnosis at stage I is approximately 90%. However, progress in improving survival in metastatic colorectal cancer (mCRC) has been minimal. This review focuses on mCRC with special emphasis on the molecular aspects of liver metastases, which is one of the most frequently involved organ site. Better molecular evidence is required to guide the decisions for surgical and other interventions used in the clinical management of mCRC. Results from different treatment modalities have exposed significant gaps in the existing paradigms of the mCRC management. Indeed there is a critical need to better understand molecular events and pathways that lead to colorectal cancer liver metastasis. Such a focused approach may help identify biomarkers and drug targets that can be useful in the clinical applications. With this focus, we provide an account of the molecular pathways involved in the spread of CRC to the liver. Specifically, the molecular changes at the DNA and RNA levels that are associated with liver metastases are discussed. Similarly, we describe relevant microRNAs that are identified as regulators of gene expression and can also serve as biomarkers. Conventionally applied biomarkers are not yet specific and sensitive enough to be relied in routine clinical decision making. Hence search for novel biomarkers is critically needed especially if these can be utilized using liquid biopsies. This review provides a comprehensive analysis of current molecular evidence along with potential future directions that could reshape the diagnostic and management paradigms and thus mitigate the devastating impact of colorectal cancer metastasis to the liver.

Anticancer effects of miR-200c in colorectal cancer through BMI1

Colorectal cancer (CRC) is one of the most leading cancer deaths throughout the world. MiR-200c has been shown to have a critical role in cancer initiation and progression. In this study, we investigated the miR-200c expression in CRC tissues and its effects on CRC cell lines which were mediated by polycomb complex protein (BMI1). Quantitative reverse transcription polymerase chain reaction (QRT-PCR) and immunohistochemistry were used to detect miR-200c and BMI1 expression in tumor tissues from 38 patients with CRC and 38 normal colon tissues. HCT-116 and SW-48 cells were transfected by locked nucleic acid (LNA)-anti-miR-200c. Western blot analysis and real-time PCR were applied to determine the BMI1 protein and microRNA (miRNA) levels. The apoptosis was analyzed via annexin/propidium iodide staining, and cell invasion was evaluated by transwell assay. MiR-200c was markedly downregulated in CRC tissues, whereas the protein expression of BMI1 in CRC tissues was upregulated compared with normal colon tissues. In the colon cancer cell lines, transfection of LNA-anti-miR-200c increased BMI1 gene and protein expression as well as the cell invasion. Downregulation of miR-200c by LNA decreased the apoptotic cells. The results from this study revealed that miR-200c may have antitumor effects through inhibition of BMI1 expression.

Current understanding and clinical utility of miRNAs regulation of colon cancer stem cells

Cancer stem cells (CSCs) in colorectal tumorigenesis are suggested to be responsible for initiation, development and propagation of colorectal cancer (CRC) and have been extensively characterized by the expression of phenotypic determinants, such as surface or intracellular proteins. The generation of CSCs is likely due to a dysregulation of the signaling pathways that principally control self-renewal and pluripotency in normal intestinal stem cells (ISCs) through different (epi)genetic changes that define cell fate, identity, and phenotype of CSCs. These aspects are currently under intense investigation. In the framework of the oncogenic signaling pathways controlled by microRNAs (miRNAs) during CRC development, a plethora of data suggests that miRNAs can play a key role in several regulatory pathways involving CSCs biology, epithelial-mesenchymal transition (EMT), angiogenesis, metastatization, and pharmacoresistance. This review examines the most relevant evidences about the role of miRNAs in the etiology of CRC, through the regulation of colon CSCs and the principal differences between colorectal CSCs and benign stem cells. In this perspective, the utility of the principal CSCs-related miRNAs changes is explored, emphasizing their use as potential biomarkers to aid in diagnosis, prognosis and predicting response to therapy in CRC patients, but also as promising targets for more effective and personalized anti-CRC treatments.

Longitudinal monitoring reveals dynamic changes in circulating tumor cells (CTCs) and CTC-associated miRNAs in response to chemotherapy in metastatic colorectal cancer patients

We evaluated the changes in CTC count and CTC-associated miRNAs during the course of chemotherapy in patients with metastatic colorectal cancer. Blood samples were collected from 9 metastatic colorectal cancer patients prior to chemotherapy and at every other chemotherapy session during the course of treatment. CTCs were isolated and enumerated using a size-exclusion method (CellSievo, Singapore). CTC-associated miRNAs were isolated using a paper-based, partitioning method, and analyzed using reverse transcription quantitative real-time PCR (MiRXES, Singapore). CTC count trends generally correlated with disease progression defined by radiological measurements and trends in carcinoembryonic antigen (CEA) levels; hence CTC counts may be useful in cases where CEA is not elevated. CTC-associated miRNAs identified were miR-15b, miR-16, miR-19a, miR-21, miR-25, miR-30d, miR-126, miR-185, miR-221, miR-222, and miR-324-5p. The expression of CTC-associated miRNAs did not appear to correlate with CTC count and exhibited inter-individual heterogeneity. This pilot study suggests that analysis of CTC changes during the course of treatment may be useful in monitoring response to therapy in metastatic colorectal cancer.

Expression of miR-200c and its clinicopathological significance in patients with colorectal cancer

MicroRNA-200c (miR-200c) is known to play a pivotal role in the regulation of epithelial-to-mesenchymal and mesenchymal-to-epithelial transition processes. However, the biological function of miR-200c in human carcinogenesis remains controversial. We examined the association of miR-200c expression with various clinicopathological factors, including KRAS mutation status and survival, in patients with colorectal cancer (CRC). The expression level of miR-200c was evaluated in 109 paired CRC and normal tissue samples using quantitative reverse transcription polymerase chain reaction. The KRAS mutation status of the CRC samples was determined using the PNAClamp™ KRAS Mutation Detection kit. Compared with the normal tissue group, miR-200c expression was significantly upregulated in the CRCs (P < .001). The expression of miR-200c was increased in CRCs with higher grade (P = .009), advanced stage (P = .042), and lymphovascular invasion (P = .003). Thirty-one CRCs (28.4%) had KRAS mutations in codon 12 or 13. CRCs with KRAS mutations had significantly higher miR-200c expression than CRCs with wild-type KRAS (P = .003). In survival analysis, high miR-200c expression was correlated with worse overall survival (P = .017) and recurrence-free survival (P = .048). Our results indicate that miR-200c is involved in tumor progression and aggressiveness in CRCs, and this oncogenic role of miR-200c may be triggered by activation of the KRAS signaling pathway.

miR-200c regulates the proliferation, apoptosis and invasion of gastric carcinoma cells through the downregulation of EDNRA expression

This study aimed to investigate the regulatory effects of microRNA (miR)‑200c on the proliferation, apoptosis and invasion of gastric carcinoma cells and to elucidate the underlying mechanisms involving the possible role of endothelin receptor A (EDNRA). The expression levels of miR‑200c and EDNRA in the gastric carcinoma cell lines, BGC‑823, SGC‑7901 and HGC‑27, and in GES‑1 normal gastric cells were evaluated by RT‑PCR and western blot analysis. The gastric carcinoma cells, particularly the BGC‑823 cells, expressed significantly lower levels of miR‑200c than the normal gastric cells (P<0.01). Thus, the BGC‑823 cells were employed as model cells. In comparison to the normal gastric cells, EDNRA was overexpressed in the gastric carcinoma cells (P<0.01). Following the transfection of the gastric carcinoma cells with miR‑200c mimics, or negative control vector (miR‑200c NC), or with siRNA targeting EDNRA (siRNA EDNRA) or negatvie control siRNA (siRNA NC), the expression levels were assessed again by RT‑PCR and western blot analysis. The successful transfection of miR‑200c mimics was observed and this markedly elevated the expression of miR‑200c (P<0.01). The transfection of miR‑200c mimics or siRNA EDNRA notably decreased the EDNRA mRNA and protein expression levels (both P<0.01). In additoin, dual‑luciferase reporter gene analysis was performed to reveal the targeting relationship between miR‑200c and EDNRA. EDNRA was found to be the downstream target gene of miR‑200c. Moreover, methyl thiazolyl tetrazolium (MTT) assay, Hoechst staining and Transwell assay were conducted to demonstrate the effects of miR‑200c mimics or siRNA EDNRA on the proliferation, apoptosis and invasion of the gastric carcinoma cells, respectively. We found that transfection with miR‑200c mimics and siRNA EDNRA were able to markedly suppress the proliferation and invasive capacity, and to promote the apoptosis of the gastric carcinoma cells (all P<0.01). On the whole, our data indicate that miR‑200c regulates the proliferation, apoptosis and invasion of gastric carcinoma cells through the downregulation of EDNRA expression.

MicroRNAs in the etiology of colorectal cancer: pathways and clinical implications

MicroRNAs (miRNAs) are small single-stranded RNAs that repress mRNA translation and trigger mRNA degradation. Of the ∼1900 miRNA-encoding genes present in the human genome, ∼250 miRNAs are reported to have changes in abundance or altered functions in colorectal cancer. Thousands of studies have documented aberrant miRNA levels in colorectal cancer, with some miRNAs reported to actively regulate tumorigenesis. A recurrent phenomenon with miRNAs is their frequent participation in feedback loops, which probably serve to reinforce or magnify biological outcomes to manifest a particular cellular phenotype. Here, we review the roles of oncogenic miRNAs (oncomiRs), tumor suppressive miRNAs (anti-oncomiRs) and miRNA regulators in colorectal cancer. Given their stability in patient-derived samples and ease of detection with standard and novel techniques, we also discuss the potential use of miRNAs as biomarkers in the diagnosis of colorectal cancer and as prognostic indicators of this disease. MiRNAs also represent attractive candidates for targeted therapies because their function can be manipulated through the use of synthetic antagonists and miRNA mimics.

Summary: This Review provides an overview of some important microRNAs and their roles in colorectal cancer.

MiR-200c regulates tumor growth and chemosensitivity to cisplatin in osteosarcoma by targeting AKT2

MicroRNAs (miRNAs) expression aberration has been discovered in almost all human cancers, thus offering a group of potential diagnostic markers, prognostic factors and therapeutic targets in tumorigenesis. Now our data showed that miR-200c, which is downregulated in osteosarcoma tissues, drives chemosensitivity to cisplatin in osteosarcoma. We demonstrated that AKT2 is a direct target of miR-200c, Spearman’s rank correlation analysis showed that the expression levels of AKT2 and miR-200c in 35 pairs of osteosarcoma specimens were inversely correlated. Moreover, miR-200c inhibited cell proliferation and cell migration. Taken together, for the first time, our results demonstrate that miR-200c plays a significant role in osteosarcoma tumor growth and chemosensitivity by regulating AKT2, which may provide a novel therapeutic strategy for treatment of osteosarcoma.

The role of Nrf2-Keap1 axis in colorectal cancer, progression, and chemoresistance

Colorectal cancer is the third common cancer after lung and genital cancers worldwide with more than 1.2 million new cases diagnosed annually. Although extensive progress has been made in the treatment of colorectal cancer, finding novel targets for early diagnosis and effective treatment of these patients is an urgent need. Nuclear factor-erythroid 2-kelch-like ECH-associated protein 1 signaling pathway plays a key role in protecting cells from the damage of intracellular oxidative stress and extracellular oxidizing agents. Nuclear factor-erythroid 2 is a transcription factor that creates intracellular redox homeostasis via transcriptional activity and interaction with kelch-like ECH-associated protein 1. Furthermore, it contributes to survival and chemoresistance of colorectal cancer cells which is mediated by overexpression of cytoprotective and multidrug resistance genes. In this review, the dual role of nuclear factor-erythroid 2 signaling in induction of colorectal cancer cell survival and death as well as the possibility of targeting nuclear factor-erythroid 2-kelch-like ECH-associated protein 1 axis as an advanced strategy in prevention and effective treatment of colorectal cancer patients have been discussed.

[The Role of MicroRNAs in Colorectal Cancer]

Colorectal cancer (CRC) is one of the leading causes of cancer related deaths in the world. Many oncogenes and tumor suppressor genes are involved in the development of CRC. MicroRNAs (miRNAs) are a class of small, non-coding, endogenous RNAs in animals and plants. Recent studies have shown that miRNAs are associated with the mediation process of tumorigenesis, including inflammation, cell cycle, stress response, differentiation, apoptosis, migration, and invasion in cancer. These miRNAs have been linked to the development of CRC and recently studied as new potential biomarkers in the diagnosis and treatment for CRC. Specific miRNAs expression patterns help distinguish CRC from other colon-related diseases, and miRNAs can target the oncogenes and regulatory molecular pathways. Recent studies have demonstrated the restoration of tumor suppressive miRNAs and inhibition of oncogenic miRNAs for CRC treatment. Herein, we describe the diagnostic and therapeutic roles of miRNAs in CRC.

Negative Correlation between miR-200c and Decorin Plays an Important Role in the Pathogenesis of Colorectal Carcinoma

Aim. To demonstrate the regulatory role of miRNA in colorectal carcinoma (CRC) and reveal the transcript markers that may be associated with CRC clinical outcomes. Method. Herein, we analyzed both mRNA and miRNA gene expression profiles of 255 CRC tumor samples from The Cancer Genome Atlas project to reveal the regulatory association between miRNA and mRNA. Also, the potential role of gene coexpression network in CRC has been explored. Results. The negative correlation between miR-200c and DCN (Decorin) was calculated in CRC, indicating that DCN could be a potential target of miR-200c. Clinical features indicated that colon polyp history and overall survival were significantly related to the expression level of miR-200c. Three coexpression networks have been constructed, and genes involved in the networks are related to cell cycle, NOTCH, and mTOR signaling pathways. Conclusion. Our result provides a new insight into cancer related mRNA coexpression network in CRC research.

MTUS1 and its targeting miRNAs in colorectal carcinoma: significant associations

Deregulated microRNA (miRNA) expression has been shown to be involved in the pathogenesis of several types of cancers including colorectal cancer (CRC). Thus, determining miRNA targets of genes that play critical role in the malignant transformation is very important. Here, expression levels of tumor suppressor microtubule-associated tumor suppressor 1 (MTUS1) and its regulatory miRNAs were reported. Predicted and validated targets of MTUS1 gene was determined by a computational approach. Expressions of MTUS1 and miRNAs were determined by using 96.96 Dynamic Array™ integrated fluidic circuit (Fluidigm). As a result, MTUS1 levels were found to be diminished in formalin-fixed, paraffin-embedded (FFPE) tissue samples of CRC patients compared to controls. Also, several of MTUS1 targeting miRNAs were found to be upregulated in CRC samples (miR-373-3p, 183-5p, 142-5p, 200c-3p, 19a-3p, -20a-5p, -181a-5p, -184, -181d-5p, -372-3p, 27b-3p, 98-5p, -let-7i-5p, -let-7d-5p, -let-7g-5p, -let-7b-5p, and -let-7c-5p). Of these miRNAs, miR-135b-5p, -373-3p, 183-5p, 142-5p, 200c-3p, 19a-3p showed marked expression levels. In contrast, expression levels of let-7a-5p, 7e-5p, 7f-5p, hsa-miR-125a-5p, and 125b-5p were found to be downregulated in CRC tissues. Accordingly, some of the overexpressed miRNAs especially the miR-135b-5p, -373-3p, 183-5p, 142-5p, 200c-3p, and 19a-3p may play key roles in CRC pathophysiology through MTUS1. In contrast, let-7a-5p, 7e-5p, 7f-5p, miR-125a-5p, and 125b-5p may play important roles in CRC carcinogenesis independent from the MTUS1. In conclusion, MTUS1 targeting miRNAs may play key roles in the development of CRC by downregulating tumor suppressor MTUS1.

Expression of microRNA miR-126 and miR-200c is associated with prognosis in patients with non-small cell lung cancer

MicroRNAs (miRNAs) are short non-coding RNAs that exert a critical influence on tumorigenesis through post-transcriptional modification and are considered to be potential biomarkers for the diagnosis or prognosis of various cancers. Although several miRNAs have been proposed as relevant biomarkers for non-small cell lung cancer (NSCLC), detailed working mechanisms and validated prognostic significance of these miRNAs remain controversial. In this study, we evaluated expression levels of miRNA-126 (miR-126) and miR-200c in 72 NSCLCs and 30 benign lung tissues by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and analyzed the correlation of miRNA expression with a variety of clinicopathological factors and patient survival. Compared with the benign control group, miR-126 expression was significantly downregulated in NSCLCs (p < 0.001), while miR-200c expression was significantly upregulated in NSCLCs (p < 0.001). The expression of miR-126 was significantly higher in NSCLCs with a tumor size of ≤3 cm than in those with a tumor size of >3 cm (p = 0.026). There were no other significant associations between miRNA expression and clinicopathological features. In univariate survival analysis for all NSCLC patients, high miR-200c expression (p = 0.037), large tumor size (p = 0.026), and lymphovascular invasion (p = 0.012) were significantly correlated with worse overall survival. High miR-126 expression was significantly associated with favorable prognosis only in patients with adenocarcinoma (p = 0.033). In multivariate analysis, miR-200c and tumor size remained as independent prognostic factors. Our results suggest that miR-126 might play tumor-suppressive and miR-200c an oncogenic role, and these miR's are potential prognostic biomarkers for NSCLC.