Up-regulation of microRNA-145 associates with lymph node metastasis in colorectal cancer

Regulatory interplay between lncRNA-FGD5-AS1 and miR-17-5p in non-small cell lung cancer progression: Implications for novel therapeutic strategies

BackgroundMicroRNA-17-5p (miR-17-5p) plays a pivotal role in the tumorigenesis and progression of non-small cell lung cancer (NSCLC) by regulating its target genes. Advances in molecular biology highlight the importance of long non-coding RNAs (lncRNAs) in cancer, yet the mechanistic interactions between miR-17-5p and lncRNAs in NSCLC remain underexplored.ObjectiveThis study investigated the regulatory interplay between miR-17-5p and lncRNA-FGD5-AS1 and evaluated their potential as targets for NSCLC therapy.MethodsA comprehensive set of technologies, including cell transfection, quantitative real-time PCR (qRT-PCR), bioinformatics analysis, and functional assays (proliferation, migration, apoptosis), was employed to examine the role of miR-17-5p and lncRNA-FGD5-AS1 in NSCLC.ResultsElevated lncRNA-FGD5-AS1 expression was observed in NSCLC cell lines A549 and H1299, correlating with poor patient prognosis. Functional assays revealed that miR-17-5p directly downregulates lncRNA-FGD5-AS1, thereby modulating key oncogenic processes. Overexpression of miR-17-5p reduced tumor cell proliferation and migration while inducing apoptosis. Conversely, miR-17-5p inhibition elevated lncRNA-FGD5-AS1 levels and reversed these effects.ConclusionThe findings identify the miR-17-5p/lncRNA-FGD5-AS1 regulatory axis as a novel therapeutic target for NSCLC. By integrating molecular and technological approaches, this study offers insights into precision oncology and highlights the potential for advanced RNA-based interventions.

NBAT1/miR-21 axis in progression of colorectal cancer and impact of PVT-1 polymorphism on miR-145 expression level and its clinical significance

Introduction

Patients with colorectal cancer (CRC) have a higher chance of survival when the disease is detected and treated effectively at an early stage. Plasmacytoma variant translocation 1 (PVT-1), an oncogenic lncRNA, and neuroblastoma associated trans-cript 1 (NBAT1), a tumor suppressor lncRNA, have been linked to CRC progression, acting as competing endo-genous RNAs to the tumor suppressor miRNA-145 and oncomiRNA-21. The aim of the current study was to construct a competing endogenous RNA (ceRNA) associated with CRC. In addition, we aimed to investigate the impact of single nucleotide polymorphisms in the rs13255292 lncRNA PVT-1 on miR-145 expression levels and the lncRNA-NBAT1/miR-21 axis in the progression of CRC.

Material and methods

Bioinforma-tic analysis was performed to determine differentially expressed genes (DEGs), differentially expressed micro-RNAs (DEMs), and differentially expressed lncRNAs (DELs) in CRC. PVT-1 rs13255292 C/T was genotyped and serum PVT-1, NBAT-1, miRNA-145 and miRNA-21 were assessed by qPCR in 85 CRC patients, 80 AP, and 85 controls.

Results

The frequencies of the PVT-1 rs13255292 CT/TT genotype and T al-le-- le were significantly elevated in the CRC group compared to the controls. PVT-1 serum levels significantly increased due to the presence of the T allele in the studied groups, which was associated with downregulation of the miR-145 tumor suppressor. Also, the expression of NBAT-1 was significantly down-expressed, while that of oncomiR-21 was significantly elevated.

Conclusions

Bioinformatics analyses provides effective identification of potential lncRNAs linked with CRC. PVT-1/miR-145 and NBAT1/miR-21 are being investigated as potential non-invasive diagnostic biomarkers for CRC.

Non-coding RNAs as Biomarkers for Survival in Colorectal Cancer Patients

Colorectal cancer (CRC) has a high incidence and fatality rate worldwide. It ranks second concerning death worldwide. Cancer patients are diagnosed with the disease at a later stage due to the absence of early diagnostic methods, which leads to increased death. With the help of recent advancements in the fields of diagnosis and therapy, the development of novel methods using new targets could be helpful for the long-term survival of CRC patients when CRC is detected early. However, the prognosis for the advanced stage of CRC is abysmal. New biomarkers are emerging as promising alternatives since they can be utilized for early detection of CRC, are simple to use, and non-invasive. Non-coding RNAs (ncRNAs) have been seen to have an aberrant expression in the development of many malignancies, including CRC. In the past two decades, much research has been done on non-coding RNAs, which may be valuable as biomarkers and targets for antitumor therapy. Non-coding RNAs can be employed in detecting and treating CRC. Non-coding RNAs play an essential role in regulating gene expression. This article reviews ncRNAs and their expression levels in CRC patients that could be used as potential biomarkers. Various ncRNAs have been associated with CRC, such as microRNAs, long non-coding RNAs, circular RNAs, etc. The expression of these non-coding RNAs may provide insights into the stages of cancer and the prognosis of cancer patients and therefore proper precautionary measures can be taken to decrease cancer-related deaths.

Emerging roles of miR-145 in gastrointestinal cancers: A new paradigm

Gastrointestinal (GI) carcinomas are a group of cancers affecting the GI tract and digestive organs, such as the gastric, liver, bile ducts, pancreas, small intestine, esophagus, colon, and rectum. MicroRNAs (miRNAs) are small functional non-coding RNAs (ncRNAs) which are involved in regulating the expression of multiple target genes; mainly at the post-transcriptional level, via complementary binding to their 3'-untranslated region (3'-UTR). Increasing evidence has shown that miRNAs have critical roles in modulating of various physiological and pathological cellular processes and regulating the occurrence and development of human malignancies. Among them, miR-145 is recognized for its anti-oncogenic properties in various cancers, including GI cancers. MiR-145 has been implicated in diverse biological processes of cancers through the regulation of target genes or signaling, including, proliferation, differentiation, tumorigenesis, angiogenesis, apoptosis, metastasis, and therapy resistance. In this review, we have summarized the role of miR-145 in selected GI cancers and also its downstream molecules and cellular processes targets, which could lead to a better understanding of the miR-145 in these cancers. In conclusion, we reveal the potential diagnostic, prognostic, and therapeutic value of miR-145 in GI cancer, and hope to provide new ideas for its application as a biomarker as well as a therapeutic target for the treatment of these cancer.

mir-145-5p is a suppressor of colorectal cancer at early stage, while promotes colorectal cancer metastasis at late stage through regulating AKT signaling evoked EMT-mediated anoikis

Background:

miR-145-5P is generally considered as a tumor suppressor at early stage of colorectal cancer, but up-regulation occurs in the progressive and later stages which is associated with metastasis, indicating miR-145-5p may play dual role in colorectal cancer (CRC). To explore the detailed mechanism of miR-145-5p in carcinogenic is of importance.

Methods:

The expression pattern of miR-145-5p in CRC patients was downloaded from TCGA database, and the probable mechanism involved in the carcinogenic effect of miR-145-5p was predicted by bioinformatics analysis. Then, interference of miR-145-5p on SW480 and SW620 cells was conducted, and the influences on tumor cell viability, invasion ability, epithelial-mesenchymal transition (EMT), anoikis, and relative protein expression were examined respectively.

Results:

A total of 522 CRC patients’ data indicated that miR-145-5p expression was significantly higher in metastatic CRC than that in non-metastatic CRC, and higher expression of miR-145-5p was correlate with worse prognosis. Overexpression of miR-145-5P-5p enhanced the proliferation and invasion ability of SW620, but inhibited them in SW480. EMT was induced in SW620 after miR-145-5p overexpression and mesenchymal–epithelial transition (MET) was induced in SW480, resulted in the decreased apoptotic rate in SW620 and elevated apoptotic rate in SW480 respectively. Western blot results showed that AKT signaling pathway was involved in the miR-145-5p evoked EMT-mediated anoikis process in SW620 and SW480 cells.

Conclusion:

miR-145-5p is a tumor suppressor at early stage of CRC, and an oncogene at advanced stage of CRC. AKT signaling evoked EMT-mediated anoikis might be the pathway by which miR-145-5P regulates CRC cell invasion and metastasis.

Biomarkers (mRNAs and Non-Coding RNAs) for the Diagnosis and Prognosis of Colorectal Cancer - From the Body Fluid to Tissue Level

In recent years, the diagnosis and treatment of colorectal cancer (CRC) have been continuously improved, but the mortality rate continues to be high, especially in advanced patients. CRC patients usually have no obvious symptoms in the early stage and are already in the advanced stage when they are diagnosed. The 5-year survival rate is only 10%. The blood markers currently used to screen for CRC, such as carcinoembryonic antigen and carbohydrate antigen 19-9, have low sensitivity and specificity, whereas other methods are invasive or too expensive. As a result, recent research has shifted to the development of minimally invasive or noninvasive biomarkers in the form of body fluid biopsies. Non-coding RNA molecules are composed of microRNAs, long non-coding RNAs, small nucleolar RNAs, and circular RNAs, which have important roles in the occurrence and development of diseases and can be utilized for the early diagnosis and prognosis of tumors. In this review, we focus on the latest findings of mRNA-ncRNA as biomarkers for the diagnosis and prognosis of CRC, from fluid to tissue level.

MicroRNA-145 targets in cancer and the cardiovascular system: evidence for common signaling pathways

miRNAs are small regulatory RNAs which govern gene expression post-transcriptionally by primarily binding to the 3'-UTR of mRNA target genes. miR-145 is a well-studied miRNA that has been implicated in controlling a range of biological processes. miR-145 is expressed in a variety of tissues and cell types and acts as a tumor-suppressor by regulating target gene signaling pathways involved in different aspects of tumor growth and progression. There is also strong evidence that highlights the important functions of miR-145 in the cardiovascular system. Here, we review the mechanisms of miR-145 in tumorigenesis and cancer progression and compare and contrast with the roles of miR-145 in cardiovascular development and disease. We discuss the important targets of miR-145 in cancer and their possible link to the cardiovascular system.

The Microrna-143/145 Cluster in Tumors: A Matter of Where and When

The establishment and spreading of cancer involve the acquirement of many biological functions including resistance to apoptosis, enhanced proliferation and the ability to invade the surrounding tissue, extravasate from the primary site, survive in circulating blood, and finally extravasate and colonize distant organs giving origin to metastatic lesions, the major cause of cancer deaths. Dramatic changes in the expression of protein coding genes due to altered transcription factors activity or to epigenetic modifications orchestrate these events, intertwining with a microRNA regulatory network that is often disrupted in cancer cells. microRNAs-143 and -145 represent puzzling players of this game, with apparently contradictory functions. They were at first classified as tumor suppressive due to their frequently reduced levels in tumors, correlating with cell survival, proliferation, and migration. More recently, pro-oncogenic roles of these microRNAs have been described, challenging their simplistic definition as merely tumor-suppressive. Here we review their known activities in tumors, whether oncogenic or onco-suppressive, and highlight how their expression and functions are strongly dependent on their complex regulation downstream and upstream of cytokines and growth factors, on the cell type of expression and on the specific tumor stage.

Long noncoding RNA LINC00520 accelerates the progression of colorectal cancer by serving as a competing endogenous RNA of microRNA-577 to increase HSP27 expression

The long noncoding RNA (lncRNA) LINC00520 is an important modulator of the oncogenicity of multiple human cancers. However, whether LINC00520 is involved in the malignant characteristics of colorectal cancer (CRC) has not been extensively studied until recently. Therefore, the present study aimed to detect LINC00520 expression in CRC and evaluate its clinical significance in patients with CRC. Functional experiments were conducted to test the biological roles and underlying mechanisms of LINC00520 in CRC progression. In this study, high-LINC00520 expression was verified in CRC tissues and cell lines, and this high expression was associated with patients' unfavorable clinicopathological parameters and shorter overall survival and disease-free survival. Functionally, interference of LINC00520 resulted in a significant decrease of CRC cell proliferation, migration, colony forming ability, and invasion. Mechanistically, LINC00520 functioned as a competing endogenous RNA by sponging microRNA-577 (miR-577) and thereby increasing heat shock protein 27 (HSP27) expression. Rescue experiments revealed that inhibiting miR-577 or restoring HSP27 could abrogate the effects of LINC00520 silencing on malignant phenotypes of CRC. LINC00520 functioned as an oncogenic lncRNA in CRC, and it facilitated CRC progression by regulating the miR-577/HSP27 axis, suggesting that the LINC00520/miR-577/HSP27 axis is an effective target in anticancer management.

Non-target Genes Regulate miRNAs-Mediated Migration Steering of Colorectal Carcinoma

MicroRNAs (miRNAs) trigger a two-layer regulatory network directly or through transcription factors and their co-regulators. Unlike miR-375, the role of miR-145 and miR-224 in inhibiting or driving cancer cell migration is controversial. This study is a step towards addressing the potential of miR-375, miR-145 and miR-224 expression modulation to inhibit colorectal carcinoma (CRC) cells migration in vitro through regulation of non-target genes VEGFA, TGFβ1, IGF1, CD105 and CD44. Transwell migration assay results revealed a significant subdue of migration ability of cells transfected with miR-375 and miR-145 mimics and miR-224 inhibitor. Real time PCR data showed that expression of VEGFA, TGFβ1, IGF1, CD105 and CD44 was downregulated as a consequence of exogenous re-expression of miR-375 and inhibition of miR-224. On the other hand, ectopic expression of miR-145 did not affect VEGFA, TGFβ1 and CD44 expression, while it elevated CD105 and suppressed IGF1 expression. MAP4K4, a predicted target of miR-145, was validated as a target that could play a role in miR-145-mediated regulation of migration. At mRNA level, no change was observed in expression of MAP4K4 in cells with restored expression of miR-145, while western blotting analysis revealed a 25% reduction of protein level. By applying luciferase reporter assay, a significant decrease in luciferase activity was observed, supporting that miR-145 directly target 3' UTR of MAP4K4. The study highlighted the involvement of non-target genes VEGFA, TGFβ1, IGF1, CD105 and CD44 in mediating anti- and pro-migratory effect of miR-375 and miR-224, respectively, and validated MAP4K4 as a direct target of anti-migratory miR-145.

MYO5A inhibition by miR-145 acts as a predictive marker of occult neck lymph node metastasis in human laryngeal squamous cell carcinoma

INTRODUCTION

Each year, ~50,000 patients worldwide die of laryngeal squamous cell carcinoma (LSCC) because of its highly metastatic properties. However, its pathogenic mechanisms are still unclear, and in particular, the prediction of metastasis remains elusive. This study aimed to define the role of microRNA-145 (miR-145) in LSCC progression. We also aimed to elucidate the clinical significance of the miR-145/MYO5A pathway, especially the predictive function of MYO5A in neck lymph node metastasis.

MATERIALS AND METHODS

MYO5A and miR-145 expression was analyzed in 132 patients with LSCC, and associations between their expression and clinicopathological features were evaluated. We validated the regulatory relationship between miR-145b and MYO5A by dual luciferase reporter assay. The role of the miR-145/MYO5A pathway in proliferation, metastasis, and apoptosis was examined in vitro. The predictive functions of MYO5A in neck lymph node metastasis and prognosis were defined according to patient follow-up.

RESULTS

Our results showed downregulation of miR-145 in LSCC, which was negatively correlated with MYO5A suppression of LSCC progression and metastasis. MiR-145 directly regulated MYO5A expression in vitro and suppressed LSCC proliferation and invasion while promoting apoptosis by inhibiting MYO5A.

CONCLUSION

Notably, overexpression of serum MYO5A in LSCC predicted cervical nodal occult metastasis and poor prognosis, providing an effective indicator for predicting neck lymph node metastasis and assessing LSCC prognosis.

Long noncoding RNA DANCR promotes colorectal cancer proliferation and metastasis via miR-577 sponging

Long non-coding RNAs (lncRNAs) play key roles in various malignant tumors, including colorectal cancer (CRC). Long non-coding RNA differentiation antagonizing non-protein coding RNA (DANCR) is overexpressed in CRC patients, but whether it affects CRC proliferation and metastasis via regulation of heat shock protein 27 (HSP27) remains unclear. In the present study, we found that DANCR was highly expressed and correlated with proliferation and metastasis in CRC. In addition, we demonstrated that DANCR and HSP27 were both targets of microRNA-577 (miR-577) and shared the same binding site. Furthermore, we revealed that DANCR promoted HSP27 expression and its mediation of proliferation/metastasis via miR-577 sponging. Finally, using an in vivo study, we confirmed that overexpression of DANCR promoted CRC tumor growth and liver metastasis. The present study demonstrated the function of DANCR in CRC and might provide a new target in the treatment of CRC.

Epigenetically regulated miR-145 suppresses colon cancer invasion and metastasis by targeting LASP1

MiR-145 is a tumor-suppressive microRNA that participates in the malignant progression of colorectal cancer (CRC). Although miR-145 has been reported to inhibit proliferation and to induce apoptosis of CRC cells, the reports about its role in invasion and metastasis are controversial. The regulation of miR-145 its own expression also requires further elucidation. In this study, we firstly found that miR-145 is markedly downregulated in the metastatic tumors of CRC patients. Then through gain- and loss-of function studies, we demonstrated that miR-145 suppresses the invasion and metastasis of CRC cells. We also provided experimental evidences which include direct binding assays and verifications on tissue specimens to confirm that LIM and SH3 protein 1 (LASP1) is a direct target of miR-145. Furthermore, we identified the core promoter regions of miR-145 and observed the cooperation between histone methylation and transcription factors through binding to these core promoter regions to regulate the expression of miR-145 in CRC cells. Our study provides an insight into the regulatory network in CRC cells, thus offering new targets for treating CRC patients.

miR-145 suppresses the proliferation, invasion and migration of NSCLC cells by regulating the BAX/BCL-2 ratio and the caspase-3 cascade

Although microRNA (miR)-145 has been identified to be a tumor suppressor in various types of tumor, it promotes the progression of non-small cell lung cancer (NSCLC). However, the precise underlying molecular mechanism of its action remains unclear. The present study investigated the effects of miR-145 on the proliferation, invasion, metastasis and apoptosis of the NSCLC A549 cell line and the underlying molecular mechanism of its action. In vitro cell proliferation, invasion, migration and apoptosis assays were employed, and the expression levels of matrix metalloproteinase (MMP)-2, MMP-9, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase-3and poly(ADP-ribose) polymerase (PARP) were evaluated by western blot analysis. The results demonstrated that ectopic expression of miR-145 inhibited the proliferation, invasion and migration of A549 cells, but promoted the apoptosis of A549 cells. Western blot analysis indicated that increased miR-145 levels led to a marked decrease in the expression of MMP-2, MMP-9 and Bcl-2. Upregulation of miR-145 expression increased the expression of Bax, thus increasing the Bax/Bcl-2 ratio. Additionally, the results indicated that miR-145 over expression promoted the cleavage of caspase-3 and PARP. Taken together, these results indicated that miR-145 suppresses the proliferative, invasive and migratory ability of A549 cells. Additionally, miR-145 upregulation induced apoptosis of A549 cells possibly by decreasing MMP-2 and MMP-9 expression, the Bax/Bcl-2 ratio and the activity of the caspase-3 cascade.

Novel circulating microRNAs expression profile in colon cancer: a pilot study

Purpose

To identify the expression profile of novel microRNAs (miRNAs) in colon cancer and evaluate their clinical applicability.

Methods

Differences in the expression of serum miRNAs in patients with colon cancer and healthy controls were identified using miRNA microarrays. Differentially expressed miRNAs were verified via real-time polymerase chain reaction (PCR) using sera from 50 patients with colon cancer and 44 healthy controls. These miRNAs were also verified in a double-blind validation experiment using sera from 30 patients with colon cancer, 30 patients with colonic polyps, and 30 healthy controls.

Results

Microarray hybridization revealed that 87 miRNAs were differentially expressed between the sera of patients with colon cancer and healthy controls. Among these miRNAs, 39 miRNAs were up-regulated, whereas 48 miRNAs were down-regulated. Verification of the expression of these miRNAs using real-time PCR revealed that the expression levels of miR-31, miR-141, miR-224-3p, miR-576-5p, and miR-4669 were significantly different between patients with colon cancer and healthy controls. Using these five miRNAs to construct a miRNA expression profile (or miRNA panel) will facilitate more effective diagnosis of colon cancer.

Conclusion

Clinical analysis of miR-31, miR-141, miR-224-3p, miR-576-5p, and miR-4669 expression in patients with colon cancer may facilitate the diagnosis of colon cancer.

MicroRNA-203 predicts human survival after resection of colorectal liver metastasis

BACKGROUND

Resection of colorectal liver metastasis (CRLM) can be curative. Predicting which patients may benefit from resection, however, remains challenging. Some microRNAs (miRNAs) become deregulated in cancers and contribute to cancer progression. We hypothesized that miRNA expression can serve as a prognostic marker of survival after CRLM resection.

RESULTS

MiR-203 was significantly overexpressed in tumors of short-term survivors compared to long-term survivors. R1/R2 margin status and high clinical risk score (CRS) were also significantly associated with short-term survival (both p = 0.001). After adjusting for these variables, higher miR-203 expression remained an independent predictor of shorter survival (p = 0.010). In the serum cohort, high CRS and KRAS mutation were significantly associated with short-term survival (p = 0.005 and p = 0.026, respectively). After adjusting for CRS and KRAS status, short-term survivors were found to have significantly higher miR-203 levels (p = 0.016 and p = 0.033, respectively).

MATERIALS AND METHODS

We employed next-generation sequencing of small-RNAs to profile miRNAs in solid tumors obtained from 38 patients who underwent hepatectomy for CRLM. To validate, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was performed on 91 tumor samples and 46 preoperative serum samples.

CONCLUSIONS

After CRLM resection, short-term survivors exhibited significantly higher miR-203 levels relative to long-term survivors. MiR-203 may serve as a prognostic biomarker and its prognostic capacity warrants further investigation.

MicroRNAs-143 and -145 induce epithelial to mesenchymal transition and modulate the expression of junction proteins

Transforming growth factor (TGF)-β is one of the major inducers of epithelial to mesenchymal transition (EMT), a crucial program that has a critical role in promoting carcinoma's metastasis formation. MicroRNAs-143 and -145, which are both TGF-β direct transcriptional targets, are essential for the differentiation of vascular smooth muscle cells (VSMC) during embryogenesis, a TGF-β-dependent process reminiscent of EMT. Their role in adult tissues is however less well defined and even ambiguous, as their expression was correlated both positively and negatively with tumor progression. Here we show that high expression of both miRs-143 and -145 in mouse mammary tumor cells expressing constitutively active STAT3 (S3C) is involved in mediating their disrupted cell-cell junctions. Additionally, miR-143 appears to have a unique role in tumorigenesis by enhancing cell migration in vitro and extravasation in vivo while impairing anchorage-independent growth, which may explain the contradictory reports about its role in tumors. Accordingly, we demonstrate that overexpression of either miRNA in the non-transformed mammary epithelial NMuMG cells leads to upregulation of EMT markers and of several endogenous TGF-β targets, downmodulation of a number of junction proteins and increased motility, correlating with enhanced basal and TGF-β-induced SMAD-mediated transcription. Moreover, pervasive transcriptome perturbation consistent with the described phenotype was observed. In particular, the expression of several transcription factors involved in the mitogenic responses, of MAPK family members and, importantly, of several tight junction proteins and the SMAD co-repressor TGIF was significantly reduced. Our results provide important mechanistic insight into the non-redundant role of miRs-143 and -145 in EMT-related processes in both transformed and non-transformed cells, and suggest that their expression must be finely coordinated to warrant optimal migration/invasion while not interfering with cell growth.

MicroRNA-184 inhibits cell proliferation and metastasis in human colorectal cancer by directly targeting IGF-1R

Colorectal cancer is currently the third most common cancer in males and the second in females worldwide. In spite of marked progress having been achieved in surgical resection, radiotherapy and chemotherapy, the prognosis for patients with colorectal cancer remains poor. Previous studies have demonstrated that the abnormal expression of microRNAs contributed to human cancer carcinogenesis and progression, suggesting miRNAs as novel therapeutic targets in colorectal cancer. The aim of the present study was to investigate the expression, functions and underlying molecular mechanisms of microRNA-184 (miR-184) in colorectal cancer. The results identified that miR-184 was significantly downregulated in colorectal cancer tissues and cell lines. In vitro functional studies demonstrated that miR-184 significantly inhibited colorectal cancer cell proliferation, migration and invasion. Notably, insulin-like growth factor 1 receptor (IGF-1R) was identified as a direct target of miR-184 in colorectal cancer. Furthermore, the functions of IGF-1R small interfering RNA were similar to those induced by miR-184 in colorectal cancer, suggesting IGF-1R as a functional target of miR-184 in colorectal cancer. The results of the present study indicated that miR-184 may be a novel therapeutic strategy regimen of targeted therapy for colorectal cancer.

Upregulation of microRNA-125b by G-CSF promotes metastasis in colorectal cancer

Although there are reports of miR-125b being dysregulated in colorectal cancer (CRC) and associated with CRC progression, little is known about its intrinsic regulatory mechanisms. Here we detected the expression of miR-125b in CRC tissues, subsequently investigated the effect of miR-125b on the proliferation, apoptosis, cell cycle and metastasis on CRC cells. Our results showed that the expression of miR-125b was significantly decreased in CRC tissues comparing to adjacent tissues. However, with the stimulation of Granulocyte colony-stimulating factor (G-CSF), which was highly expressed in CRC tissues, the expression of miR-125b could be improved. Analysis of patient samples revealed that miR-125b presented a clear association with poor differentiation, positive lymph node metastasis, and advanced TNM stage. Overexpression of miR-125b inhibited cell proliferation, triggered G2/M cell cycle arrest, induced subsequent apoptosis, and promoted cell migration and invasion. Moreover, luciferase reporter assays and western blot clarified that the myeloid cell leukemia 1 (MCL1) was a direct target of miR-125b. Thus overexpression of MCL1 attenuated the pro-metastasis function of miR-125b in CRC cell lines. In addition, the protein expression level of MCL1 was decreased in CRC tissues from patients with positive lymph node metastasis, which had high miR-125b expression. Collectively, our study suggested that miR-125b induced by G-CSF plays a promoting role in the metastasis of CRC by targeting MCL1, which may serve as a novel therapeutic target for CRC metastasis.

MicroRNA-330 inhibited cell proliferation and enhanced chemosensitivity to 5-fluorouracil in colorectal cancer by directly targeting thymidylate synthase

Colorectal cancer (CRC) is the third most common cancer in males and the second most common in females, worldwide. Currently, 5-fluorouracil (5-FU)-mediated chemotherapy is the adjuvant treatment for patients with CRC following surgical resection. However, a number of patients with CRC develop 5-FU resistance, which is a major challenge for the effective treatment of cancer. Therefore, it is important to investigate the molecular mechanisms underlying chemoresistance and the therapeutic treatments that may improve the treatment of CRC. The present study demonstrated that microRNA (miR)-330 was significantly downregulated in CRC tissues and cell lines. Ectopic miR-330 expression decreased cell proliferation and enhanced cell chemosensitivity to 5-FU via the cell apoptosis pathway in CRC. In addition, thymidylate synthase (TYMS) was revealed to be a direct target gene of miR-330 in CRC. Knockdown of TYMS inhibited CRC cell proliferation, and enhanced cell chemosensitivity to 5-FU by promoting cell apoptosis. In conclusion, the results of the present study indicated that miR-330 targeted TYMS to inhibit the proliferation and enhance the chemosensitivity of CRC cells to 5-FU by promoting cell apoptosis. The present study provided important insight into the molecular mechanism underlying 5-FU-mediated chemoresistance and a novel therapeutic strategy for the enhancement of efficacy in CRC treatment.

Downregulation of microRNA-100/microRNA-125b is associated with lymph node metastasis in early colorectal cancer with submucosal invasion

A majority of early colorectal cancers (CRCs) with submucosal invasion undergo surgical operation, despite a very low incidence of lymph node metastasis. Our study aimed to identify microRNAs (miRNAs) specifically responsible for lymph node metastasis in submucosal CRCs. MicroRNA microarray analysis revealed that miR-100 and miR-125b expression levels were significantly lower in CRC tissues with lymph node metastases than in those without metastases. These results were validated by quantitative real-time PCR in a larger set of clinical samples. The transfection of a miR-100 or miR-125b inhibitor into colon cancer HCT116 cells significantly increased cell invasion, migration, and MMP activity. Conversely, overexpression of miR-100 or miR-125b mimics significantly attenuated all these activities but did not affect cell growth. To identify target mRNAs, we undertook a gene expression array analysis of miR-100-silenced HCT116 cells as well as negative control cells. The Ingenuity Pathway Analysis, TargetScan software analyses, and subsequent verification of mRNA expression by real-time PCR identified mammalian target of rapamycin (mTOR) and insulin-like growth factor 1 receptor (IGF1R) as direct, and Fas and X-linked inhibitor-of-apoptosis protein (XIAP) as indirect candidate targets for miR-100 involved in lymph node metastasis. Knockdown of each gene by siRNA significantly reduced the invasiveness of HCT116 cells. These data clearly show that downregulation of miR-100 and miR-125b is closely associated with lymph node metastasis in submucosal CRC through enhancement of invasion, motility, and MMP activity. In particular, miR-100 may promote metastasis by upregulating mTOR, IGF1R, Fas, and XIAP as targets. Thus, miR-100 and miR-125b may be novel biomarkers for lymph node metastasis of early CRCs with submucosal invasion.

Role of STAT3 and FOXO1 in the Divergent Therapeutic Responses of Non-metastatic and Metastatic Bladder Cancer Cells to miR-145

Although miR-145 is the most frequently downregulated miRNA in bladder cancer, its exact stage association and downstream effector have not been defined. Here, we found that miR-145 was upregulated in human patients with bladder cancer with lymph node metastasis and in metastatic T24T cell line. Forced expression of miR-145 promoted anchorage-independent growth of T24T cells accompanied by the downregulation of forkhead box class O1 (FOXO1). In contrast, in non-metastatic T24 cells, miR-145 overexpression inhibited cell growth with upregulation of FOXO1, and the knockdown of FOXO1 abolished the miR-145-mediated inhibition of cell growth. Mechanistic studies revealed that miR-145 directly bound to and attenuated 3'-untranslated region (UTR) activity of foxo1 mRNA in both T24 and T24T cells. Interestingly, miR-145 suppressed STAT3 phosphorylation at Tyr705 and increased foxo1 promoter transcriptional activity in T24 cells, but not in T24T cells, suggesting a role of STAT3 in the divergent responses to miR-145. Supporting this was our finding that STAT3 knockdown mimicked miR-145-mediated upregulation of FOXO1 in T24T cells and inhibition of anchorage-independent growth. Consistently, ectopic expression of miR-145 promoted tumor formation of xenograft T24T cells, whereas such promoting effect became inhibitory due to specific knockdown of STAT3. Together, our findings demonstrate the stage-specific association and function of miR-145 in bladder cancers and provide novel insights into the therapeutic targeting of miR-145. Mol Cancer Ther; 16(5); 924-35. ©2017 AACR.

A microRNA-based prediction model for lymph node metastasis in hepatocellular carcinoma

We developed an efficient microRNA (miRNA) model that could predict the risk of lymph node metastasis (LNM) in hepatocellular carcinoma (HCC). We first evaluated a training cohort of 192 HCC patients after hepatectomy and found five LNM associated predictive factors: vascular invasion, Barcelona Clinic Liver Cancer stage, miR-145, miR-31, and miR-92a. The five statistically independent factors were used to develop a predictive model. The predictive value of the miRNA-based model was confirmed in a validation cohort of 209 consecutive HCC patients. The prediction model was scored for LNM risk from 0 to 8. The cutoff value 4 was used to distinguish high-risk and low-risk groups. The model sensitivity and specificity was 69.6 and 80.2 %, respectively, during 5 years in the validation cohort. And the area under the curve (AUC) for the miRNA-based prognostic model was 0.860. The 5-year positive and negative predictive values of the model in the validation cohort were 30.3 and 95.5 %, respectively. Cox regression analysis revealed that the LNM hazard ratio of the high-risk versus low-risk groups was 11.751 (95 % CI, 5.110–27.021; P < 0.001) in the validation cohort. In conclusion, the miRNA-based model is reliable and accurate for the early prediction of LNM in patients with HCC.

miR-145 suppresses colorectal cancer cell migration and invasion by targeting an ETS-related gene

MicroRNA-45 (miR-145) has been demonstrated to be downregulated in various cancer types including colorectal cancer (CRC). However, the function of miR‑145 in CRC has not been clearly elucidated. In this study, we examined miR-145 expression by quantitative real‑time PCR (qRT‑PCR) in CRC cell lines as well as tumors and corresponding normal mucosa, and the results were correlated to the clinicopathological parameters. In addition, using computational algorithms we investigated putative miR‑145 targets. The role of miR‑145 was further examined in studies in vitro. In our study miR‑145 was significantly decreased in CRC tissues and cell lines compared with non‑cancerous colorectal mucosa, especially lymph node or distance metastasis cases. Based on computational algorithms, we assumed that ERG was directly modulated by miR‑145 in colorectal cancer cells. For the first time, we demonstrated that ERG was highly expressed in CRC tissues compared with normal ones by qRT‑PCR. The inverse correlation between the expression of miR‑145 and ERG was observed in CRC tissues. Dual‑Luciferase assays demonstrated the direct interaction between miR‑145 and 3'‑UTR of ERG mRNA. Ectopic expression of miR‑145 suppressed the proliferation and invasion ability of colorectal cancer cells, while ERG knockdown partially restored the tumor suppressive effect of miR‑145. These results suggested that miR‑145 might act as a tumor suppressor during the process of CRC malignant transformation by interacting with ERG.

A functional variant rs353292 in the flanking region of miR-143/145 contributes to the risk of colorectal cancer

MicroRNA (miR)-143 and miR-145 have been identified as molecular regulators in cell proliferation, cell growth, clone formation, apoptosis, cell cycle, invasion, and migration. We previously found that rs353292 in the flanking region of miR-143/145 showed a high frequency in patients with colorectal cancer (CRC). To identify whether the rs353292 polymorphism is a risk factor for CRC, we conducted this study with larger samples. A total of 809 patients with CRC and 1005 gender matched controls were collected. The rs353292 polymorphism was genotyped by using TaqMan allelic discrimination. Dual luciferase reporter assay was carried out to measure the transcriptional activity. We found that the rs353292 polymorphism was associated with an increased risk for developing CRC in heterozygous comparison (adjusted OR = 1.70, 95% CI, 1.32–2.20, P < 0.001), dominant genetic model (adjusted OR = 1.62, 95% CI, 1.26–2.09, P < 0.001), and allele comparison (adjusted OR = 1.46, 95% CI, 1.16–1.84, P = 0.001). The rs353292 CT/TT carriers exhibited a lower expression of miR-143 compared to the CC carriers (P = 0.04). Moreover, the pGL3-rs353292T displayed a significantly lower luciferase activity than pGL3-rs353292C (P < 0.01). These findings indicate that the rs353292 polymorphism is functional and may be a risk factor for the development of CRC.

MicroRNA-103 promotes tumor growth and metastasis in colorectal cancer by directly targeting LATS2

Colorectal cancer (CRC) has become the third most common cancer worldwide and leads to a high mortality rate. Although colorectal cancer has been studied widely, the underlying molecular mechanism remains unclear. Increasing evidence shows that the abnormal expression of microRNAs (miRNAs) is involved in tumorigenesis. Previous studies have reported that miRNA-103 (miR-103) is dysregulated in CRC; however, the expression, function and mechanism of miR-103 in CRC are not well known. The present study showed that miR-103 was overexpressed in the primary tumor tissues of patients with CRC and was significantly associated with a more aggressive phenotype of CRC in patients. Survival rate analysis demonstrated that CRC patients with high miR-103 expression had a poorer overall survival compared with CRC patients with low miR-103 expression. In CRC cell lines, miR-103 inhibition significantly decreased the proliferation, invasion and migration of the cells in vitro. Furthermore, miR-103 repressed large tumor suppressor kinase 2 (LATS2) expression by directly binding to the LATS2-3'-untranslated region, and an inverse correlation was identified between the expression of miR-103 and LATS2 messenger RNA in primary CRC tissues. In addition, the restoration of LATS2 led to suppressed proliferation, invasion and migration of CRC cells. In vivo, miR-103 promotes tumor growth in nude mice. In summary, miR-103 performs a critical role in the promotion of the invasive and metastatic capacities of CRC, possibly by directly targeting LATS2. This miRNA may be involved in the development and progression of CRC.

Phenotypic switching of vascular smooth muscle cells in the 'normal region' of aorta from atherosclerosis patients is regulated by miR-145

Switching of vascular smooth muscle cells (VSMCs) from a contractile phenotype to an adverse proliferative phenotype is a hallmark of atherosclerosis or vascular restenosis. However, the genetic modulators responsible for this switch have not been fully elucidated in humans nor have they been correlated with clinical abnormalities. This study investigated genetic mechanisms involved in phenotypic switching of VSMCs at non-defect areas of the aorta in patients with atherosclerosis. Aortic wall samples were obtained from patients with (N = 53) and without (N = 27) atherosclerosis undergoing cardiovascular surgery. Vascular smooth muscle cell cultures were generated, and expression of microRNA-145 (miR-145), its target gene Kruppel-Like Factor 5 (KLF5) and Myocardin (MYOCD, a smooth muscle-specific transcriptional coactivator) were analysed using RT-qPCR, along with expression of relevant proteins. Vascular smooth muscle cells were transduced with miR-145 inhibitor and mimic to determine the effect of miR-145 expression on VSMC proliferation. miR-145 expression decreased while KLF5 expression increased in atherosclerotic aortas. Atherosclerotic samples and VSMCs had decreased expression of contractile markers calponin and alpha smooth muscle actin (α-SMA) and MYOCD. miR-145 inhibitor-transduced VSMCs from non-atherosclerotic patients showed decreased expression of calponin and α-SMA and increased proliferation compared with non-transduced controls, and these levels were close to those of atherosclerotic patients. miR-145 mimic-transduced VSMCs from atherosclerotic patients showed increased expression of calponin and α-SMA and decreased proliferation compared with non-transduced controls, and these levels were close to those found in non-atherosclerotic patients. These data demonstrate that miR-145 modulates the phenotypic switch of VSMCs from a contractile to a proliferative state via KLF5 and MYOCD in atherosclerosis.

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.

Upregulation of microRNA-204 inhibits cell proliferation, migration and invasion in human renal cell carcinoma cells by downregulating SOX4

MicroRNA-204 (miR-204) has been reported to be frequently downregulated in various types of cancer, including renal, brain, ovary, hematological and colon cancer. The present study, investigated the effects of miR‑204 on renal cell carcinoma. Following transfection of miR‑204, an MTT assay, cell migration assay, cell invasion assay, western blot analysis and luciferase assay were performed in renal cell carcinoma cell lines. It was demonstrated that miR‑204 inhibits cell proliferation, migration and invasion in 786‑O and A498 cells. To the best of our knowledge, this study is the first to demonstrate that miR‑204 directly targets SOX4 in renal cell carcinoma. These results suggested that miR-204 may have value as a marker for the early detection of tumor metastasis and a therapeutic target preventing the invasion of renal cell carcinoma.

Identification and validation of potential biomarkers for the detection of dysregulated microRNA by qPCR in patients with colorectal adenocarcinoma

Colorectal cancer represents a lethal disease that has raised concern and has attracted significant attention. Adenocarcinoma is the most common type of colorectal cancer (CRC). MicroRNAs are thought to be potential biomarkers of CRC. Many researchers have focused on the expression pattern of miRNAs in CRC. However, previous studies did not pay particular attention to the effects of the degree of differentiation of the cancer with respect to the miRNA expression profile. First, this study compared the expression level of 1547 miRNAs by qRT-PCR in Colorectal adenocarcinoma tissues to that in paired normal tissues. In all, 93 miRNAs were identified that were significantly dysregulated in Colorectal adenocarcinoma relative to normal tissues (P<0.05). Then, we analyzed their potential as cancer biomarkers by ROC analysis, and the result revealed that three miRNAs with high sensitivity and specificity are suitable as biomarkers for the diagnosis of CRC (the value of the AUC was greater than 0.7). Interestingly, previous reports of 23 of these miRNAs have been scarce. Furthermore, we wanted to analyze the difference between well- and moderately differentiated cancers, and as expected, 58 miRNAs showed significant dysregulation. Importantly, 32 miRNAs were able to not only distinguish cancer tissues from normal tissues, but they were also able to identify well- and moderately differentiated cancers. In conclusion, the degree of differentiation has an important influence on the miRNA expression pattern. To avoid misdiagnoses and missed diagnoses, tumors of different degrees of differentiation should be treated differently when miRNAs are used as cancer biomarkers.

An update on miRNAs as biological and clinical determinants in colorectal cancer: a bench-to-bedside approach

Colorectal carcinogenesis represents a sequential progression of normal colonic mucosa from adenoma to carcinoma. It has become apparent that miRNA deregulation contributes to the initiation and progression of colorectal cancer (CRC). These oncogenic or tumor-suppressive miRNAs interact with intracellular signaling networks and lead to alteration of cell proliferation, apoptosis, metastasis and even response to chemotherapeutic treatments. This article aims to review the cutting edge progress in the discovery of the role of novel mechanisms for miRNAs in the development of CRC. We will also discuss the potential use of miRNAs as biomarkers for early diagnosis and prognosis of CRC. Furthermore, with advancements in RNA delivery technology, it is anticipated that manipulation of miRNAs may offer an alternative therapy for CRC treatment.

MiR-145 expression accelerates esophageal adenocarcinoma progression by enhancing cell invasion and anoikis resistance

BACKGROUND

Carcinoma of the esophagus has a high case fatality ratio and is now the 6th most common cause of cancer deaths in the world. We previously conducted a study to profile the expression of miRNAs in esophageal adenocarcinoma (EAC) pre and post induction therapy. Of the miRNAs differentially expressed post induction chemoradiation, miR-145, a known tumor suppressor miRNA, was upregulated 8-fold following induction therapy, however, its expression was associated with shorter disease-free survival. This unexpected result was explored in this current study.

METHODS

In order to study the role of miR-145 in EAC, miRNA-145 was overexpressed in 3 EAC cell lines (OE33, FLO-1, SK-GT-4) and one ESCC cell line (KYSE-410). After validation of the expression of miR-145, hallmarks of cancer such as cell proliferation, resistance to chemotherapy drugs or anoikis, and cell invasion were analyzed.

RESULTS

There were no differences in cell proliferation and 5 FU resistance between miR145 cell lines and the control cell lines. miR-145 expression also had no effect on cisplatin resistance in two of three cell lines (OE33 and FLO-1), but miR-145 appeared to protect SK-GT-4 cells against cisplatin treatment. However, there was a significant difference in cell invasion, cell adhesion and resistance to anoikis. All three EAC miR-145 cell lines invaded more than their respective controls. Similarly, OE33 and SK-GT-4 miR-145 cell lines were able to survive longer in a suspension state.

DISCUSSION

While expression of miR-145 in ESCC stopped proliferation and invasion, expression of miR-145 in EAC cells enhanced invasion and anoikis resistance. Although more work is required to understand how miR-145 conveys these effects, expression of miR-145 appears to promote EAC progression by enhancing invasion and protection against anoikis, which could in turn facilitate distant metastasis.