c-Met and miRs in Cancer. Biomedicines. 2015;3:32-44. [PMID: 28536397 PMCID: PMC5344231 DOI: 10.3390/biomedicines3010032]

Non-coding RNAs as potential therapeutic targets for receptor tyrosine kinase signaling in solid tumors: current status and future directions

This review article presents an in-depth analysis of the current state of research on receptor tyrosine kinase regulatory non-coding RNAs (RTK-RNAs) in solid tumors. RTK-RNAs belong to a class of non-coding RNAs (nc-RNAs) responsible for regulating the expression and activity of receptor tyrosine kinases (RTKs), which play a critical role in cancer development and progression. The article explores the molecular mechanisms through which RTK-RNAs modulate RTK signaling pathways and highlights recent advancements in the field. This include the identification of potential new RTK-RNAs and development of therapeutic strategies targeting RTK-RNAs. While the review discusses promising results from a variety of studies, encompassing in vitro, in vivo, and clinical investigations, it is important to acknowledge the challenges and limitations associated with targeting RTK-RNAs for therapeutic applications. Further studies involving various cancer cell lines, animal models, and ultimately, patients are necessary to validate the efficacy of targeting RTK-RNAs. The specificity of ncRNAs in targeting cellular pathways grants them tremendous potential, but careful consideration is required to minimize off-target effects, the article additionally discusses the potential clinical applications of RTK-RNAs as biomarkers for cancer diagnosis, prognosis, and treatment. In essence, by providing a comprehensive overview of the current understanding of RTK-RNAs in solid tumors, this review emphasizes their potential as therapeutic targets for cancer while acknowledging the associated challenges and limitations.

Clinicopathological and prognostic values of MET expression in pancreatic adenocarcinoma based on bioinformatics analysis

Pancreatic adenocarcinoma (PAAD) is regarded as one of the most lethiferous cancers worldwide because treatment of pancreatic cancer remains challenging and mostly palliative. Little progress had been made to select certain reliable biomarkers as clinical prognosis. In this context, GSE28735 and GSE16515 were obtained from the Gene Expression Omnibus (GEO). GEO2R tool was used to recognize differentially expressed genes (DEGs). 351 DEGs were screened which included 230 up-regulated genes and 121 down-regulated genes. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to analyze the DEGs and associated signal pathways in the DAVID database. A protein-protein interaction (PPI) network was then constructed to screen 10 hub genes by STRING database and Cityscape software. Analyses of 10 hub genes were performed on GEPIA database and GSCA database, which revealed that MET was high expressed and significantly associated with survival of PAAD patients. Immunohistochemical staining showed that MET was higher expressed in PAAD tissues than adjacent tissues in 20 samples. The clinicopathological analysis revealed that high expression of MET was associated with the degree of differentiation, lymph node metastasis, vascular cancer thrombus and nerve invasion in PAAD tissues (P < .05). Furthermore, the Tumor Immune Estimation Resource (TIMER) database analyzed the correlation between the MET expression level and immune infiltration levels, which elucidated that MET expression was appreciably positively correlated with the infiltration levels of myeloid-derived suppressor cells (MDSCs). Here, these results strongly indicate MET is an unique prognostic biomarker. Its expression level is correlated with certain clinicopathological features and immune cell infiltration.

Long non-coding RNAs: an overview on miRNA sponging and its co-regulation in lung cancer

Lung cancer is the most devastating cause of death among all cancers worldwide, and non-small cell lung cancer (NSCLC) accounts for 80% of all the lung cancer cases. Beyond common genetic research and epigenomic studies, the extraordinary investigations of non-coding RNAs have provided insights into the molecular basis of cancer. Existing evidence from various cancer models highlights that the regulation of non-coding RNAs is crucial and that their deregulation may be a common reason for the development and progression of cancer, and competition of cancer therapeutics. Non-coding RNAs, such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are increasingly recognized as potential cancer biomarkers for early detection and application of therapeutic strategies. The miRNAs have gained importance as master regulators of target mRNAs by negatively regulating their expression. The lncRNAs function as both tumor suppressors and oncogenes, and also compete with miRNAs that influence the translational inhibition processes. This review addresses the role of lncRNAs in lung cancer development, highlights their mechanisms of action, and provides an overview of the impact of lncRNAs on lung cancer survival and progression via miRNA sponging. The improved understanding of lung cancer mechanisms has opened opportunities to analyze molecular markers and their potential therapeutics.

Silencing CircEIF3I/miR-526b-5p Axis Epigenetically Targets HGF/c-Met Signal to Hinder the Malignant Growth, Metastasis and Angiogenesis of Hepatocellular Carcinoma

BACKGROUND

Hepatocyte growth factor (HGF)/c-mesenchymal-epithelial transition factor (c-Met) is important for the diagnosis and prognosis of hepatocellular carcinoma (HCC). Circular RNAs (circRNAs) are key regulators of HCC progression, and this study focused on circRNA eukaryotic translation initiation factor 3 subunit I (circEIF3I) with HGF/c-Met in HCC.

METHODS

Levels of circEIF3I, microRNA (miR)-526b-5p, HGF, E-cadherin, N-cadherin, and Vimentin were detected by Gene Expression Omnibus database, quantitative PCR and western blotting. Cell functions were measured by detecting cell growth (cell proliferation assay with WST-1 and EdU, colony formation assay, flow cytometry, caspase 3 activity assay, and nude mouse tumorigenicity assay), metastasis (transwell assay and western blotting), angiogenesis (endothelial tube formation assay). Molecular interaction was determined dual-luciferase reporter assay, RNA immunoprecipitation, and Pearson correlation analysis.

RESULTS

Expression of circEIF3I was upregulated in HCC tissues. Knockdown of circEIF3I suppressed cell proliferation epithelial-mesenchymal transition, migration, invasion and tube formation ability but promoted apoptosis of HCC cells. CircEIF3I could sponge miR-526b-5pto regulate downstream HGF. Functionally, circEIF3I regulation in HCC cell progression was associated with miR-526b-5p sponging function and HGF upregulation could attenuate tumor-inhibiting roles of miR-526b-5p. HCC tumor growth was delayed by interfering circEIF3I.

CONCLUSION

CircEIF3I was an oncogenic circRNA in HCC-, and interfering circEIF3I exhibited anti-HCC activity via circEIF3I-miR-526b-5p-HGF/c-Met pathway.

MicroRNA-367 Inhibits Breast Cancer and Promotes Apoptosis by Targeting AT-Rich Interactive Domain-Containing Protein 1B

Introduction: Breast cancer (BC) developed in the glandular epithelial tissue of breast. microRNA (miR)-367 is an important player in cancer progression, but has never been studied in BC. This experiment tries to probe the mechanism of miR-367 in BC treatment with downstream target gene. Materials and Methods: Human BC cell lines and healthy breast epithelium cells were applied in this study. After the transfection of miR-367 inhibitor or mimic into BC cells, functional assays were conducted to measure cell growth. Afterwards, flow cytometry was employed in apoptosis verification. Then, target relation between miR-367 and ARID1B was certified. Furthermore, ARID1B level was also measured. Results: miR-367 was underexpressed in human BC cells (p < 0.05). Besides, overexpressed miR-367 inhibited BC cell proliferation and encouraged apoptosis, while underexpressed miR-367 led to an opposite outcome (p < 0.05). This experiment then implied that miR-367 dramatically suppressed the activity of cell transfected with ARID1B-wild type. miR-367 overexpression quenched ARID1B level in BC cells; while silencing miR-367 upregulated ARID1B expression (p < 0.05). Conclusion: Our experiment discovered that miR-367 quenched BC cell growth and promoted apoptosis by targeting ARID1B. This investigation may provide novel insights in BC treatment.

Dual inhibition of RNAi therapeutic miR-26a-5p targeting cMet and immunotherapy against EGFR in endometrial cancer treatment

Background

Precise prediction of drug combination targeting tumor cells effectively is a crucial challenge for tumor therapy, especially for endometrial cancer (EC). Considering the resistance, crosstalk that occurs between the receptor tyrosine kinase mesenchymal-epithelial transition factor (cMet) and epidermal growth factor receptor (EGFR), and their indispensable influence on the occurrence of EC, this study aimed to explore a novel therapeutic approach for EC treatment through blocking cMet and EGFR simultaneously.

Methods

In the present study, the expression of miR-26a-5p in EC cell lines was detected using quantitative real-time polymerase chain reaction assay. The potential role of miR-26a-5p in the development of EC was examined using cell counting kit assay, 5-ethynyl-2’- deoxyuridine staining, wound healing assay, and cell apoptosis staining assay. Subsequently, the effect of upregulated miR-26a-5p in vivo was confirmed on a xenograft model. Luciferase reporter assay and Western blot analysis were performed to verify the relation between miR-26a-5p and cMet. Furthermore, the dual therapeutic effect of miR-26a-5p and EGFR monoclonal antibody cetuximab was confirmed in vivo and in vitro.

Results

The results indicated that miR-26a-5p expression significantly reduced in EC cell lines compared with the normal endometrial cell line. Furthermore, the overexpression of miR-26a-5p inhibited the progression of EC, including cell migration, cell proliferation, and cell apoptosis in vivo and in vitro. Subsequently, mir-26a-5p regulated the expression of cMet and the downstream the hepatocyte growth factor (HGF)/cMet pathway, thus exerting an inhibitory effect on EC cells. In addition, the study also demonstrated that the upregulation of miR-26a-5p could significantly enhance the inhibitory effect of cetuximab compared with the use of cetuximab alone in vivo and in vitro.

Conclusions

RNAi therapeutic miR-26a-5p suppressed the progression of EC through regulating the cMet/HGF pathway. The dual therapy using RNA interference and neutralizing antibody simultaneously blocked tumor targets, including cMet and EGFR, thus providing a novel approach for overcoming the resistance to the inhibitors against a single target in EC treatment.

PretiMeth: precise prediction models for DNA methylation based on single methylation mark

Background

The computational prediction of methylation levels at single CpG resolution is promising to explore the methylation levels of CpGs uncovered by existing array techniques, especially for the 450 K beadchip array data with huge reserves. General prediction models concentrate on improving the overall prediction accuracy for the bulk of CpG loci while neglecting whether each locus is precisely predicted. This leads to the limited application of the prediction results, especially when performing downstream analysis with high precision requirements.

Results

Here we reported PretiMeth, a method for constructing precise prediction models for each single CpG locus. PretiMeth used a logistic regression algorithm to build a prediction model for each interested locus. Only one DNA methylation feature that shared the most similar methylation pattern with the CpG locus to be predicted was applied in the model. We found that PretiMeth outperformed other algorithms in the prediction accuracy, and kept robust across platforms and cell types. Furthermore, PretiMeth was applied to The Cancer Genome Atlas data (TCGA), the intensive analysis based on precise prediction results showed that several CpG loci and genes (differentially methylated between the tumor and normal samples) were worthy for further biological validation.

Conclusion

The precise prediction of single CpG locus is important for both methylation array data expansion and downstream analysis of prediction results. PretiMeth achieved precise modeling for each CpG locus by using only one significant feature, which also suggested that our precise prediction models could be probably used for reference in the probe set design when the DNA methylation beadchip update. PretiMeth is provided as an open source tool via https://github.com/JxTang-bioinformatics/PretiMeth.

MicroRNA signature in patients with hepatocellular carcinoma associated with type 2 diabetes

BACKGROUND

Nonalcoholic steatohepatitis-related cirrhosis is one of the liver complications in type 2 diabetes mellitus (T2DM) and reported to be a risk factor for developing hepatocellular carcinoma (HCC). A reliable screening biomarker of liver cirrhosis (LC) and HCC among T2DM patients is important to reduce the morbidity and mortality of this disease. MicroRNA (miRNA) is considered a key player in HCC and T2DM, and it might be a hidden culprit in diabetes-associated HCC, making it a promising reliable prognostic tool.

AIM

To investigate the signature of serum miRNAs as early biomarkers for the screening of HCC among diabetic patients.

METHODS

Expression profiles of miRNAs in serum samples of diabetic LC and diabetic HCC patients were assessed using Illumina sequencing; then, RT-qPCR was used to validate significantly altered miRNAs between the two groups. Candidate miRNAs were tested in serum samples of 200 T2DM patients, 270 LC patients, 200 HCC patients, and 225 healthy control subjects. Additionally, receiver operating characteristic (ROC) analysis, with area under the curve (AUC), was performed to assess the diagnostic performance of the screened miRNAs for discriminating HCC from LC and nonmalignant patients (LC + T2DM).

RESULTS

Expression of the sequenced miRNAs in serum was different in HCC vs LC-positive T2DM patients. Two miRNAs (miR-34a, miR-221) were significantly up-regulated and five miRNAs (miR-16, miR-23-3p, miR-122-5p, miR-198, miR-199a-3p) were significantly down-regulated in HCC compared to LC patients. Analysis of ROC curve demonstrated that the combination of these seven miRNAs can be used as a reliable biomarker for detection of HCC in diabetic patients, as it could identify HCC with high diagnostic accuracy in diabetic LC patients (AUC = 0.993) and in diabetic nonmalignant patients (AUC = 0.961).

CONCLUSION

This study validates a panel of serum miRNAs that can be used as a reliable noninvasive screening biomarker of HCC among T2DM cirrhotic and noncirrhotic patients. The study recommends further research to shed light on a possible role of c-Met in T2DM-associated HCC via the miRNA regulatory pathway.

c-Met as a new marker of cellular senescence

Here, we reported for the first time an increased expression of c-Met protein in primary cultures of human dermal and pulmonary fibroblasts of late passages. This suggests that c-Met could serve as an early marker of cellular senescence (CS). The levels of c-Met-related signaling proteins phospho-Akt and Stat3 were also increased in (pre)senescent fibroblasts. Considering the anti-apoptotic activity of Akt and the involvement of Stat3 in mediating the effects of proinflammatory cytokines, the findings of this study indicate that c-Met could contribute through its downstream targets or partners to at least two major phenotypical features of CS - resistance to apoptosis and senescence-associated secretory phenotype.

MicroRNA-562 negatively regulated c-MET/AKT pathway in the growth of glioblastoma cells

Background

MicroRNA-562 (miR-562) has been found to possess anti-cancer function in certain tumors. However, the function of miR-562 in glioblastoma (GBM) is still not fully understood.

Purpose

The aim at present study is to analyze the function of miR-562 and its possible target in GBM cells.

Patients and methods

In the present study, a total of 80 GBM samples and 16 adjacent noncancerous tissues were used to examine the expression of miR-562 and c-MET. In order to gain a deep insight into the molecular network of miR-562 and c-MET in GBM, the miR-562 mimic and inhibitor were transfected into two GBM cell lines (U251 and U87), respectively. Meanwhile, lentiviral vector was used to mediate overexpression of c-MET. Cell proliferation was examined via Cell Counting Kit-8 (CCK-8) assays. Meanwhile, cell apoptosis was analyzed by Annexin V-FTTC/PI staining assay.

Results

Our results indicated that the level of miR-562 was downregulated in GBM tissues and the expression of c-MET was upregulated in tumors. Cell proliferation analysis indicated that miR-562 was an anti-proliferation effector in GBM cells. Moreover, cell apoptosis analysis suggested the pro-apoptosis function of miR-562 in GBM cells.

Conclusion

Our results demonstrated that miR-562 negatively regulated the c-MET/AKT signal pathway. In addition, caspase-3 might also serve as another target for miR-562 in GBM cells. This research not only obtained a deep understanding of miR-562 but also provided evidence in terms of developing new prognostic biomarker for GBM.

Evaluation of pre-mir-34a rs72631823 single nucleotide polymorphism in triple negative breast cancer: A case-control study

Aim

The purpose of this study is to evaluate the role of pre-miR34a rs72631823 as potential risk factor and/or prognostic marker in patients with triple negative breast cancer.

Methods

114 samples of DNA from paraffin embedded breast normal tissues of patients with triple negative breast cancer and 124 samples of healthy controls were collected and analyzed for pre-miR34a rs72631823 polymorphism.

Results

Pre-miR34a rs72631823 A allele was associated with increased TNBC risk both in univariate and multivariate analysis. The number of pre-miR34a rs72631823 AA subjects was very small and the association did not reach significance (p = 0.176, Fisher’s exact test). The examined polymorphism was not associated with overall survival at the univariate or multivariate Cox regression analysis (adjusted HR = 1.60, 95%CI: 0.64–3.96 for miR34 rs72631823 GA/AA vs. GG).

Conclusion

Our case-control study suggests that pre-miR34a rs72631823 A allele is associated with increased triple negative breast cancer risk.

HGF/c-MET: A Promising Therapeutic Target in the Digestive System Cancers

The HGF/c-MET pathway is active in the development of digestive system cancers, indicating that inhibition of HGF/c-MET signaling may have therapeutic potential. Various HGF/c-MET signaling inhibitors, mainly c-MET inhibitors, have been tested in clinical trials. The observed efficacy and adverse events of some c-MET inhibitors were not very suitable for treating digestive system cancers. The development of new HGF/c-MET inhibitors in preclinical studies may bring promising treatments and synergistic combination (traditional anticancer drugs and c-MET inhibitors) strategies provided anacceptable safety and tolerability. Insights into miRNA biology and miRNA therapeutics have made miRNAs attractive tools to inhibit HGF/c-MET signaling. Recent reports show that several microRNAs participate in inhibiting HGF/c-MET signaling networks through antagonizing c-MET or HGF in digestive system cancers, and the miRNAs-HGF/c-MET axis plays crucial and novel roles for cancer treatment. In the current review, we will discuss recent findings about inhibitors of HGF/c-MET signaling in treating digestive system cancers, and how miRNAs regulate digestive system cancers via mediating HGF/c-MET pathway.

The putative tumor suppressor, miR-199a, regulated by Snail, modulates clear cell renal cell carcinoma aggressiveness by repressing ROCK1

Background

Aberrant expression of miR-199a has been frequently reported in cancer studies; however, its role in renal cell carcinoma (RCC) has not been examined in detail.

Results

Here, we showed that miR-199a was downregulated in RCC and associated with poor prognostic phenotype. Using luciferase and western blot assays we identified that Rho-associated coiled coil-containing protein kinases 1 (ROCK1) was a direct target gene for miR-199a. miR-199a regulated proliferation, invasion, and apoptosis of clear cell renal cell carcinoma (ccRCC) cells by modulating ROCK1 expression. Interestingly, we also found that miR-199a was modulated by snail in ccRCC cells. Snail elevated ROCK1 expression by repressing miR-199a activity.

Conclusion

Altogether, our results identify a crucial tumor suppressive role of miR-199a in the progression of ccRCC and suggest that miR-199a might be an anticancer therapeutic target for ccRCC patients.