New trends in molecular and cellular biomarker discovery for colorectal cancer

BMP7 mediates the anticancer effect of honokiol by upregulating p53 in HCT116 cells

Colorectal cancer (CRC) is the second leading cause of cancer death. Hence, there is a great need to explore new efficacious drugs for the treatment of CRC. Honokiol (HNK), a natural product extracted from magnolia bark, processes various biological activities, including anticancer. In this study, we introduced cell viability assay, western blotting, real-time PCR and immunofluorescent staining to determine the anticancer effect of HNK, and the possible mechanism underlying this biological process. We found that HNK can inhibit the proliferation and induce apoptosis in HCT116 cells in a concentration- and time-dependent manner. HNK activates p53 in HCT116 and other colon cancer cells. Exogenous p53 potentiates the anticancer of HNK, while p53 inhibitor decreases this effect of HNK. Moreover, HNK upregulates the expression of bone morphogenetic protein 7 (BMP7) in colon cancer cells; Exogenous BMP7 enhances the anticancer activity of HNK and BMP7 specific antibody reduces this effect of HNK. For mechanism, we found that HNK cannot increase the level of Smad1/5/8; Exogenous BMP7 potentiates the HNK-induced activation of p53. On the contrary, BMP7 specific antibody inhibits the HNK-induced activation of p53 in colon cancer cells and partly decreases the total level of p53. Our findings suggested that HNK may be a promising anticancer drug for CRC; activation of p53 plays an important role in the anticancer activity of HNK, which may be initialized partly by the HNK-induced upregulation of BMP7.

Systematic literature review and clinical validation of circulating microRNAs as diagnostic biomarkers for colorectal cancer

Because patients with colorectal cancer (CRC) are usually diagnosed at an advanced stage and current serum tumor markers have limited diagnostic efficacy, there is an urgent need to identify reliable diagnostic biomarkers. To better define the diagnostic potential of microRNAs (miRNAs) for CRC, we performed a comprehensive evaluation of reported circulating CRC miRNA markers. After a systematic literature review, we selected 30 candidate miRNAs and used quantitative real-time polymerase chain reaction to examine their expression in a training cohort of 120 plasma samples (CRC vs healthy controls (HC) = 60:60). Expression data was confirmed in a validation cohort of 160 plasma samples (CRC vs HC = 80:80). We ultimately identified 5 dysregulated circulating miRNAs (miR-15b, miR-17, miR-21, miR-26b, and miR-145), of which miR-21 and miR-26b proved to have the best diagnostic performance in the training and validation cohorts, respectively. Based on these results, we propose a novel blood-based diagnostic model, integrating 5 CRC-related miRNAs and serum carcinoembryonic antigen (CEA), which provides better diagnostic performance than the combined 5 miRNAs, CEA alone, or any single miRNA. We propose that the novel CRC diagnostic model presented here will be useful for overcoming the limitations faced by current non-invasive diagnostic strategies.

Genetic and epigenetic markers in colorectal cancer screening: recent advances

INTRODUCTION

Colorectal cancer (CRC) is a heterogenous disease which develops from benign intraepithelial lesions known as adenomas to malignant carcinomas. Acquired alterations in Wnt signaling, TGFβ, MAPK pathway genes and clonal propagation of altered cells are responsible for this transformation. Detection of adenomas or early stage cancer in asymptomatic patients and better prognostic and predictive markers is important for improving the clinical management of CRC. Area covered: In this review, the authors have evaluated the potential of genetic and epigenetic alterations as markers for early detection, prognosis and therapeutic predictive potential in the context of CRC. We have discussed molecular heterogeneity present in CRC and its correlation to prognosis and response to therapy. Expert commentary: Molecular marker based CRC screening methods still fail to gain trust of clinicians. Invasive screening methods, molecular heterogeneity, chemoresistance and low quality test samples are some key challenges which need to be addressed in the present context. New sequencing technologies and integrated omics data analysis of individual or population cohort results in GWAS. MPE studies following a GWAS could be future line of research to establish accurate correlations between CRC and its risk factors. This strategy would identify most reliable biomarkers for CRC screening and management.

Potential role of miR-139-5p in cancer diagnosis, prognosis and therapy

MicroRNAs (miRNAs) are short non-coding RNAs that regulate the expression of protein-coding genes by partially binding to specific target sites of mRNAs. miRNAs perform important functions in complicated cellular biological processes and their abnormal expression is involved in various disorders, including cancer. Among the miRNAs, differential expression of miR-139-5p serves a significant role in tumorigenesis, metastasis and recurrence, thus suggesting that it may potentially be used as a promising biomarker for cancer diagnosis, prognosis and therapy. miR-139-5p is expected to serve as a biomarker to eventually be implemented in a clinical setting. In the present review, we focus on the importance of miR-139-5p in cancer, summarize the association between miR-139-5p expression level and diagnosis and prognosis, and discuss the potential therapeutic implications for the future.

Longitudinal Analysis of Serum Autoantibody-Reactivities in Patients with Primary Open Angle Glaucoma and Optic Disc Hemorrhage

Background

The aim of our current investigation was to analyze the autoantibody-reactivities of primary open angle glaucoma patients with optic disc hemorrhage as possibly correlated to disease progression by means of a protein microarray approach.

Methods

Sera of patients with primary open angle glaucoma and optic disc hemorrhage (n = 16) were collected directly after study inclusion (0 weeks) and after 2 weeks, 4 weeks and 12 weeks. As a control group patients with primary open angle glaucoma (n = 18) were used (0 weeks and 12 weeks). Microarrays were incubated and occurring antibody-antigen-reactions were visualized with fluorescence labeled anti-human-IgG secondary antibodies. To detect changes in autoantibodies spot intensities were digitized and compared.

Results

With respect to the immunoreactivity at 0 weeks level increment of anti-adaptor protein 1 complex subunit mu-1 antibodies and anti-SPRY domain-containing SOCS box protein 3 antibodies in sera of primary open angle patients with optic disc hemorrhage was detected. Linear trend analysis revealed a positive correlation with r ≥ 0.8 between antibody-level and time course. Control group show no relevant changes in the same period. Significant changes were found in time point 4 comparison between patient groups in anti-adaptor protein 1 complex subunit mu-1-level (p = 0.01). No significant changes in visual acuity were found.

Conclusion

With this approach we were able to detect autoimmune reactivities in sera of patients with primary open angle glaucoma and optic disc hemorrhage compared to patients without optic disc hemorrhage. These antibodies could give further insights into the pathogenesis and the autoimmune component of glaucomatous optic neuropathy.

Dual specificity phosphatase 5 is a novel prognostic indicator for patients with advanced colorectal cancer

Dual specificity phosphatase 5 (DUSP5) is a negative regulator of Mitogen-activated protein kinase (MAPK) signaling pathway and has recently been identified as a tumor suppressor in several human malignancies. However, its clinical significance in colorectal cancer (CRC) remains unclear. In this study, we aimed to investigate the potential utility of DUSP5 as a novel biomarker for progression indication and chemotherapy benefit in CRC patients. Through quantitative real time-polymerase chain reaction and western blot, we determined that DUSP5 expression is dramatically lower in CRC tissues than that in matched normal tissues. The statistical analysis based on immunohistochemistry revealed that DUSP5 expression is significantly correlated with tumor differentiation, TNM stage, lymph node metastasis and distant metastasis. For the whole study cohort, patients with high DUSP5 expression had a better CRC-specific and disease-free survival than those with low DUSP5 expression and DUSP5 expression is an independent prognostic factor for patient survival. In subgroup analysis, DUSP5 has no prognostic significance in low-risk stage II patients, but could predict treatment response in high-risk stage II and stage III/IV patients who received standard FOLFOX chemotherapy scheme. Finally, the correlation analysis suggested that DUSP5 expression is associated with Epithelial-to-Mesenchymal Transition (EMT) phenotype in CRC tissues, suggesting that downregulated DUSP5 may contribute to poor prognosis partly by involving EMT. Taken together, our study proposes that DUSP5 is a promising biomarker for predicting CRC progression and advanced patients with high DUSP5 expression appear to benefit from standard FOLFOX chemotherapy scheme.