The comparison of miR-155 with computed tomography and computed tomography plus serum amyloid A protein in staging rectal cancer

Translational Potential of MicroRNAs for Preoperative Staging and Prediction of Chemoradiotherapy Response in Rectal Cancer

Colorectal cancer is the third most common cancer and the second cause of cancer-related deaths. Rectal cancer presents roughly one-third of all colorectal cancer cases and differs from it on both anatomical and molecular levels. While standard treatment of colon cancer patients is radical surgery, rectal cancer is usually treated with pre-operative chemoradiotherapy followed by total mesorectal excision, which requires precise estimation of TNM staging. Unfortunately, stage evaluation is based solely on imaging modalities, and they often do not correlate with postoperative pathological findings. Moreover, approximately half of rectal cancer patients do not respond to such pre-operative therapy, so they are exposed to its toxic effects without any clinical benefit. Thus, biomarkers that could precisely predict pre-operative TNM staging, and especially response to therapy, would significantly advance rectal cancer treatment—but till now, no such biomarker has been identified. In cancer research, microRNAs are emerging biomarkers due to their connection with carcinogenesis and exceptional stability. Circulating miRNAs are promising non-invasive biomarkers that could allow monitoring of a patient throughout the whole therapeutic process. This mini-review aims to summarize the current knowledge on miRNAs and circulating miRNAs involved in the prediction of response to treatment and pre-operative staging in rectal cancer patients.

The cross-talk between adipokines and miRNAs in health and obesity-mediated diseases

BACKGROUND

Multiple studies have revealed a direct correlation between obesity and the development of multiple comorbidities, including metabolic diseases, cardiovascular disorders, chronic inflammatory disease, and cancers. However, the molecular mechanism underlying the link between obesity and the progression of these diseases is not completely understood. Adipokines are factors that are secreted by adipocytes and play a key role in whole body homeostasis. Collaboratively, miRNAs are suggested to have key functions in the development of obesity and obesity-related disorders. Based on recently emerging evidence, obesity leads to the dysregulation of both adipokines and obesity-related miRNAs. In the present study, we described the correlations between obesity and its related diseases that are mediated by the mutual regulatory effects of adipokines and miRNAs.

METHODS

We reviewed current knowledge of the modulatory effects of adipokines on miRNAs activity and their relevant functions in pathological conditions and vice versa.

RESULTS

Our research reveals the ability of adipokines and miRNAs to control the expression and activity of the other class of molecules, and their effects on obesity-related diseases.

CONCLUSIONS

This study may help researchers develop a roadmap for future investigations and provide opportunities to develop new therapeutic and diagnostic methods for treating obesity-related diseases.

Repression of lncRNA NEAT1 enhances the antitumor activity of CD8+T cells against hepatocellular carcinoma via regulating miR-155/Tim-3

BACKGROUND

Immunotherapy is a promising method for the treatment of hepatocellular carcinoma (HCC), in which CD8⁺T cells play a key role. The influence of long noncoding RNA (lncRNA) nuclear-enriched autosomal transcript 1(NEAT1) on the antitumor activity of CD8⁺T cells was clarified in this study.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from HCC patients, and the expressions of NEAT1 and Tim-3 were determined by qRT-PCR and western blot, respectively. CD8⁺T cell apoptosis and cell percentage were analyzed via flow cytometry. The cytolysis activity of CD8⁺T cells against HCC cells was examined. RNA immunoprecipitation (RIP) and RNA pull-down assay were performed to explore the interaction between NEAT1 and miR-155.

RESULTS

NEAT1 and Tim-3 were up-regulated in the PBMCs of patients with HCC (n = 20) compared with healthy subjects (n = 20). Down-regulation of NEAT1 restrained CD8⁺T cell apoptosis and enhanced the cytolysis activity, while interference of miR-155 showed the opposite effects by up-regulating Tim-3. Binding and interaction between NEAT1 and miR-155 were validated in CD8⁺T cells. Down-regulation of NEAT1 restrained CD8⁺T cell apoptosis and enhanced the cytolysis activity through the miR-155/Tim-3 pathway. Repression of NEAT1 suppressed tumor growth in HCC mice.

CONCLUSION

Via modulating the miR-155/Tim-3 pathway, repression of NEAT1 restrained CD8⁺T cell apoptosis and enhanced the cytolysis activity against HCC, implying an effective target for improving the outcome of immunotherapy.

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.

MicroRNA Expression Profiling to Identify and Validate Reference Genes for the Relative Quantification of microRNA in Rectal Cancer

Introduction

MicroRNAs (miRNAs) play important roles in regulating biological processes at the post-transcriptional level. Deregulation of miRNAs has been observed in cancer, and miRNAs are being investigated as potential biomarkers regarding diagnosis, prognosis and prediction in cancer management. Real-time quantitative polymerase chain reaction (RT-qPCR) is commonly used, when measuring miRNA expression. Appropriate normalisation of RT-qPCR data is important to ensure reliable results. The aim of the present study was to identify stably expressed miRNAs applicable as normaliser candidates in future studies of miRNA expression in rectal cancer.

Materials and Methods

We performed high-throughput miRNA profiling (OpenArray®) on ten pairs of laser micro-dissected rectal cancer tissue and adjacent stroma. A global mean expression normalisation strategy was applied to identify the most stably expressed miRNAs for subsequent validation. In the first validation experiment, a panel of miRNAs were analysed on 25 pairs of micro dissected rectal cancer tissue and adjacent stroma. Subsequently, the same miRNAs were analysed in 28 pairs of rectal cancer tissue and normal rectal mucosa.

Results

From the miRNA profiling experiment, miR-645, miR-193a-5p, miR-27a and let-7g were identified as stably expressed, both in malignant and stromal tissue. In addition, NormFinder confirmed high expression stability for the four miRNAs. In the RT-qPCR based validation experiments, no significant difference between tumour and stroma/normal rectal mucosa was detected for the mean of the normaliser candidates miR-27a, miR-193a-5p and let-7g (first validation P = 0.801, second validation P = 0.321). MiR-645 was excluded from the data analysis, because it was undetected in 35 of 50 samples (first validation) and in 24 of 56 samples (second validation), respectively. Significant difference in expression level of RNU6B was observed between tumour and adjacent stromal (first validation), and between tumour and normal rectal mucosa (second validation).

Conclusion

We recommend the mean expression of miR-27a, miR-193a-5p and let-7g as normalisation factor, when performing miRNA expression analyses by RT-qPCR on rectal cancer tissue.

Integrated analysis of differentially expressed mRNAs and miRNAs between hepatocellular carcinoma and their matched adjacent normal liver tissues

Hepatocellular carcinoma has a high mortality rate, thus, there is a need for improvement of prognosis of such patients. The aim of the present study was to identify differentially expressed mRNAs and miRNAs between hepatocellular carcinoma tissues and their matched adjacent normal liver tissues, and to carry out a bioinformatics analysis. Agilent 8x60K microarray technology was used to detect the changes of mRNA and miRNA expression between hepatocellular carcinoma tissues and their matched adjacent normal liver tissues. To select differentially expressed mRNAs and miRNAs, gene ontology (GO) and pathway analysis were performed using bioinformatics methods. qPCR was used to verify the microarray data. As a result, 924 mRNAs and 21 miRNAs exhibited a higher expression in the hepatocellular carcinoma tissue than their matched adjacent normal liver tissue. In comparison with the adjacent normal tissue, the carcinoma tissue showed a downregulated expression of 1,770 mRNAs and 12 miRNAs. The GO and pathway analysis showed that these RNAs were involved in the transcription process, REDOX, signal transduction, ion transport, immune response, cell adhesion and binding functions. A total of 572 target genes of 14 miRNAs were identified, most of which were involved in tumors. The results of qPCR were in concordance with the microarray results. In summary, the differentially expressed mRNAs and miRNAs that include signal transduction, immune response and many other key links may provide novel targets for early diagnosis and therapy of hepatocellular carcinoma.

MicroRNA-155 hallmarks promising accuracy for the diagnosis of various carcinomas: results from a meta-analysis

Background. Recent studies have shown that microRNAs (miRNAs) have diagnostic values in various cancers. This meta-analysis seeks to summarize the global diagnostic role of miR-155 in patients with a variety of carcinomas. Methods. Eligible studies were retrieved by searching the online databases, and the bivariate meta-analysis model was employed to generate the summary receiver operator characteristic (SROC) curve. Results. A total of 17 studies dealing with various carcinomas were finally included. The results showed that single miR-155 testing allowed for the discrimination between cancer patients and healthy donors with a sensitivity of 0.82 (95% CI: 0.73–0.88) and specificity of 0.77 (95% CI: 0.70–0.83), corresponding to an area under curve (AUC) of 0.85, while a panel comprising expressions of miR-155 yielded a sensitivity of 0.76 (95% CI: 0.68–0.82) and specificity of 0.82 (95% CI: 0.77–0.86) in diagnosing cancers. The subgroup analysis displayed that serum miR-155 test harvested higher accuracy than plasma-based assay (the AUC, sensitivity, and specificity were, resp., 0.87 versus 0.73, 0.78 versus 0.74, and 0.77 versus 0.70). Conclusions. Our data suggest that single miR-155 profiling has a potential to be used as a screening test for various carcinomas, and parallel testing of miR-155 confers an improved specificity compared to single miR-155 analysis.