Polymorphism in miR-31 and miR-584 binding site in the angiotensinogen gene differentially influences body fat distribution in both sexes

Angiotensinogen (AGT), its active fragments and microRNA-31 (miR-31) play an important role in adipocyte differentiation. AGT contains a miR-31 polymorphic binding site. We hypothesize that the rs7079 polymorphism in the miR-31/584 binding site of the AGT gene could influence body fat distribution. A total of 751 subjects (195 men, 556 women) were enrolled in the study. The rs7079 genotypes were determined by qRT-PCR. Anthropometric measurements were taken on all subjects, who were subsequently divided into two groups: obese (>30 kg m(-2)) and non-obese (<30 kg m(-2)). Linear regression models were created to determine the contributions of sex, obesity status and rs7079 to all measured parameters. Adding the rs7079 genotype significantly contributed to the linear regression model for waist circumference (p = 0.013), hip circumference (p = 0.018) and supraspinal skin-fold thickness (p = 1 × 10(-3)). Differences between sexes and between the obese and non-obese groups were observed. Waist circumference was lower in men carrying the A allele (p = 0.022); hip circumference was higher only in obese women carrying the A allele (p = 0.015). While men carrying the A allele had lower supraspinal skin-fold thickness (p = 0.022), this parameter was found to be higher in A allele carrying women (p = 3 × 10(-3)). The higher total sum of skin-fold thickness in A allele carrying women was restricted to obese individuals (p = 0.028). The presence of the A allele was associated with both lower tricipital skin-fold thickness in non-obese women (p = 0.023) and a trend of higher thickness in non-obese men (p = 0.065). Significant associations of rs7079 in the AGT gene and body fat distribution were observed. The distribution followed opposing patterns in both sexes.

Abstract 160: ZFAS1, long non-coding RNA with significance in colorectal cancer

Introduction: Colorectal cancer (CRC) is one of the most common cancers in the world. However, the existence of multiple known carcinogens and varying genetic backgrounds makes it difficult to determine which factors are most important in the development of CRC. Therefore, the identification of a bona fide molecule involved in progression of CRC has been greatly sought after. Long noncoding RNAs (lncRNA) are emerging as key molecules in human cancer, and some of them were shown to have potential for cancer diagnosis and prognosis. ZFAS1, an lncRNA, has been recently revealed involving in human breast cancer as putative tumor suppressor. However, whether ZFAS1 is involved in CRC pathogenesis or could serve as novel biomarker in CRC is unknown.

Patients and methods: By use of high throughput technology we identified ZFAS1 as one of the highly up-regulated lncRNA in CRC tissue. Thus, aim of the current study was to explore the correlation between ZFAS1 expression and progression of CRC and its clinical significance. The expression levels of ZFAS1 were determined by quantitative real-time PCR and in selected cases by Northern blot and evaluated in larger cohort (120 cases) of CRC tissues and cell lines (HCT116, DLD1, SW620), which were compared to paired adjacent normal tissues or normal colonic cell lines. The potential relationship between ZFAS1 levels in tumor tissues and the clinicopathological features of CRC was also evaluated. Further, we assessed whether ZFAS1 influences cell proliferation, apoptosis, cell cycle and migration in-vitro. The different isoforms of ZFAS1 were determined by RACE-PCR and protein interacting partners of ZFAS1 were analyzed by pull-down experiment and mass spectrometry. The identified candidate proteins were evaluated by RNA-IP.

Results: Our results showed that ZFAS1 expression in CRC tissues and cell lines were significantly increased compared with matched normal tissues (p &lt; 0.0001). In addition, siRNA-mediated knockdown of ZFAS1 expression significantly influenced the proliferation of CRC cells (p &lt; 0.05) Interestingly, ZFAS1 intronically hosts three C/D box snoRNAs (SNORDs): SNORD12, 12B, and 12B. The general assumption that noncoding SNORD-host transcripts function only as vehicles to generate snoRNAs, knockdown of ZFAS1 in a CRC cell lines resulted in decreased cellular proliferation, while not substantially altering the levels of the SNORDs.

Conclusion: Our current study demonstrates that ZFAS1 levels are increased in CRC tissue and influences significantly proliferation of CRC cells in vitro, indicating its potential oncogenic functioning in CRC.

The work has been supported by Project CZ.1.07/2.3.00/30.0037, and IGA MZCR NT13549-4/2012, NT13860-4/2012.

Citation Format: Nithyananda Thorenoor, Petra Vychytilova, Jitka Mlcochova, Sonja Hombach, Markus Kretz, Jiri Sana, Ondrej Slaby. ZFAS1, long non-coding RNA with significance in colorectal cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 160. doi:10.1158/1538-7445.AM2015-160

Abstract 237: Piwi genes and tissue/serum piR-651 are related to clinicopathologic features of renal cell carcinoma

Introduction: Piwi-interacting RNAs (piRNAs) consists a newly discovered class of non-coding RNA. PiRNAs were first identified in the germ cells of various animal species. They bind to Piwi proteins which are a subfamily of Argonaut proteins. In humans were identified four Ago genes and four Piwi genes. Human Piwi genes include PIWIL1, PIWIL2, PIWIL3 and PIWIL4. Recent studies suggest that deregulated expression of Piwi proteins is common to many types of tumors and also correlate with clinicopathologic features and worse prognosis in patients with breast, cervical, ovarian, colorectal and other cancers. PiRNAs are short single-stranded RNAs with 26-31 nucleotides in length. They are involved in silencing of transposable elements and it is assumed that also participate in sequence-specific chromatin modifications. The differential expression of piRNAs was found in gastric and breast cancer. In our pilot study we analyzed expression of Piwi genes and piR-651, which was previously found to be deregulated in various types of tumors.

Patients and Methods: In our study, we have used the tumor tissue and the paired renal parenchyma tissue of 56 patients with renal cell carcinoma (RCC). From the tissue was isolated total RNA and by RT-qPCR were examined the expression of Piwi genes and piR-651. For the analysis of circulating piR-651, blood serum samples of 75 patients with RCC and 75 age, gender-matched healthy donors were used. We have compared expression levels of the studied genes in tumor and non-tumor tissues, serum samples, and also correlated them with clinicopathologic features of RCC patients (stage, grade, RFS, OS).

Results: We found a significant down-regulation of PIWIL1 (p&lt;0,0001) and piR-651 (p&lt;0,0001) expression levels in tumor tissue when compared to paired renal parenchyma samples. The expression levels of PIWIL2, PIWIL3 and PIWIL4 were not significantly deregulated in tumor tissue. Interestingly, levels of PIWIL2 and PIWIL4 correlated significantly with the stage (p = 0,002 and p = 0,003, resp.) and grade (p = 0.007 and p&lt;0.0001, resp.) of RCC. We found also a correlation between higher levels of PIWIL1 and overall survival (p&lt;0.05). We have observed significantly decreased expression levels of piR-651 in blood serum samples of RCC patients when compared to healthy donors and accordingly to ROC analysis we were able to distinguish blood serum of RCC patients and control subjects with the sensitivity of 77.33% and a specificity of 72.37%. Expression levels of serum piR-651 were not in correlation with the stage and grade of RCC.

Conclusion: Accordingly to our pilot data expression of Piwi genes is altered in tumor tissue and is correlated to selected clinicopathologic features of RCC. We also suggest the potential of piR-651 in blood serum as novel non-invasive diagnostic biomarker in RCC.

Acknowledgments: IGA MZCR No: NT/13860-4/2012, NT/13549-4/2012, NT/13547-4/2012, NT/13514-4/2012

Citation Format: Robert Iliev, Petra Vychytilova-Faltejskova, Jaroslav Juracek, Hana Mlcochova, Michal Stanik, Jan Dolezel, Michal Fedorko, Dalibor Pacik, Marek Svoboda, Ondrej Slaby. Piwi genes and tissue/serum piR-651 are related to clinicopathologic features of renal cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 237. doi:10.1158/1538-7445.AM2015-237

Abstract 4006: MiRNA profiling in esophageal precancerous for malignancy progression risk assessment

Background: Barrett's esophagus (BE) is a metaplastic disease with risk to develop esophageal adenocarcinoma (EAC). Current screening method for BE patients (endoscopy and biopsy) is discomfort, expensive and relatively risky for patients. Moreover, the procedure is complicated by subjective histopathology examination and only 2% of BE patients annually progress to adenocarcinoma. The aim of our study was to identify miRNA profiles in order to predict cancer progression in high-risk BE patients.

Methods and patients: FFPE samples were obtained from 113 patients (35 EAC, 21 low-grade dysplasia of esophagus, 33 BE and 24 healthy control). There were 74 males and 39 females; mean age was 55.9 years, range 15 - 94 years. Total RNA was purified from FFPE biopsy samples using proteinase K treatment followed by RNeasy kit (Qiagen). Microarray analysis was performed using the GeneChip miRNA 3.0 Array (Affymetrix). The data were analyzed using “R” software and the Bioconductor package.

Results: In total, 113 GeneChip miRNA 3.0 Arrays were performed in 113 patients. Expression profiles of 1733 human miRNAs were analyzed. In supervised clustering analysis we found 8 differentially expressed miRNAs (p&lt;0.001 or logFC 2) in BE patients compared to EAC patients and 10 differentially expressed miRNAs (p&lt;0.001 or logFC 2) in LGD patients compared to EAC patients. One of the dominant findings was decreased expression of miR-223 in EAC and LGD samples, which is known to function as a tumor suppressor blocking E2F1. Using LOOCV classifier with 13 miRNAs signature we were able to correctly classify 86 from 113 samples (AUC = 0.840). Prediction model fails mostly in LGD prediction (18/21), probably due to incorrect pathological classification.

Conclusion: We have identified miRNA profiles and signature allowing for better diagnostics of cancer progression in BE and LGD patients, which, however, will require further validation.

Acknowledgment: This work was financially supported by IGA UP LF 2014_019, NPU LO1304, CZ.1.05/2.1.00/01.0030 and CZ.1.07/2.3.00/30.0004.

Citation Format: Josef Srovnal, Ondrej Slaby, Jiri Ehrmann, Jan Gregar, Lenka Radova, Katerina Staffova, Marian Hajduch. MiRNA profiling in esophageal precancerous for malignancy progression risk assessment. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4006. doi:10.1158/1538-7445.AM2015-4006

Abstract 5256: MiRNA-31-5p expression in glioblastoma tissue and effects of its replacement in glioblastoma cells

Introduction:

Glioblastoma multiforme (GBM) is the most malignant primary tumor of the central nervous system of adults. Our previous study has showed significant alterations in expression of microRNAs (miRNAs) in GBM tissue. Some of these miRNAs were also correlated with overall survival, whereas miR-31-5p was the most significant, indicating its tumor suppressive functioning. In this study, miR-31-5p was studied on larger cohort of GBM patients and also in vitro of selected GBM cell lines.

Patients, Cell lines and Methods:

Expression of miR-31-5p was validated on cohort of 58 GBM patients and 10 samples of non-tumor brain tissue. We have increased expression level of miR-31-5p using transient transfection of specific miRNA mimic in GBM cell lines A172, U87MG, T98MG, and U251. Cell viability and proliferation were analyzed using MTT assay and cell counting, respectively. Cell cycle analyses were performed by flow-cytometry using propidium iodide. Migration and invasion potential were measured by the wound healing assay and transwell invasion assay, respectively. Finally, potential targets of miR-31-5p were discovered using combination of bioinformatics algorithms for target prediction and GeneChip Human Gene 2.0 ST Array (Affymetrix) whole-genome expression profiling.

Results:

Down-regulation of miR-31-5p was successfully validated on cohort of 58 GBM patients and 10 samples of non-tumor brain tissue (p&lt;0.001). MiR-31-5p was significantly associated also with progression-free and overall survival of GBM patients. Transient expression of miR-31-5p led to the significant decrease of GBM cell proliferation and viability in A172, U87MG, T98G, and U251 cell lines (t-test; p &lt; 0.05) due to the cell cycle arrest in G1 phase. Moreover, transfected A172 and U251 cells had a lower migration and invasiveness potential in comparison with control cells (t-test; p &lt; 0.05). Finally, analysis of global gene expression profiles together with predicted mRNA targets revealed several interesting targets of miR-31-5p, which are involved in crucial signaling pathways of GBM.

Conclusion:

Taken together, our data suggest that miR-31-5p is not only powerful diagnostic marker as showed previously but seems to be promising therapeutic target in GBM patients. This work was supported by grants of Internal Grant Agency of the Czech Ministry of Health no. NT13514-4/2012, NT/13860-4/2012, NT/13549-4/2012, NT/13547-4/2012; and project “CEITEC - Central European Institute of Technology” (CZ.1.05/1.1.00/02.0068).

Citation Format: Jiri Sana, Andrej Besse, Jakub Ondracek, Marek Vecera, Pavel Fadrus, Leos Kren, Hana Mlcochova, Robert Illiev, Jitka Mlcochova, Petra Vychytilova, Renata Hezova, Jaroslav Juracek, Ondrej Slaby. MiRNA-31-5p expression in glioblastoma tissue and effects of its replacement in glioblastoma cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5256. doi:10.1158/1538-7445.AM2015-5256

MiR-21, miR-34a, miR-198 and miR-217 as diagnostic and prognostic biomarkers for chronic pancreatitis and pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma is an aggressive malignancy with late presentation, metastatic potential and very poor prognosis. Therefore, there is an urgent need for novel diagnostic and prognostic biomarkers. MicroRNAs are small non-coding RNAs that post-transcriptionally regulate gene expression. Altered expression of microRNAs has been reported in wide range of malignancies, including pancreatic ductal adenocarcinoma. The aim of this study was to analyze the expression of selected microRNAs in normal pancreas, chronic pancreatitis and pancreatic ductal adenocarcinoma tissues and evaluate their diagnostic and prognostic potential.

FINDINGS

Using quantitative real-time PCR, expression levels of 4 microRNAs were examined in 74 tumor tissues, 18 tissues of chronic pancreatitis and 9 adjacent normal tissues and correlated with clinicopathological features of patients. Expression levels of miR-21, miR-34a and miR-198 were significantly higher, whereas levels of miR-217 were significantly lower in pancreatic ductal adenocarcinomas compared to healthy tissues and tissues of chronic pancreatitis. Moreover, increased expression of miR-21 and miR-198 was significantly associated with shorter disease free survival and overall survival.

CONCLUSIONS

Our data suggest that altered expression of examined microRNAs is related to neoplastic transformation and progression of the disease and these microRNAs could serve as diagnostic and prognostic biomarkers for pancreatic ductal adenocarcinoma.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1373952531543898.

Dynamic changes in microRNA expression profiles reflect progression of Barrett's esophagus to esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is highly aggressive malignancy that frequently develops from Barrett's esophagus (BE), a premalignant pathologic change occurring in the lower end of the esophagus. MicroRNAs (miRNAs) are small, non-coding RNAs that function as posttranscriptional regulators of gene expression and were repeatedly proved to play key roles in pathogenesis of BE as well as EAC. In our study, we used Affymetrix GeneChip miRNA arrays to obtain miRNA expression profiles in total of 119 tissue samples [24 normal esophageal mucosa (EM), 60 BE and 35 EAC]. We identified a number of miRNAs, that showed altered expression progressively in sequence EM, BE and EAC, including for instance miR-21, miR-25, miR-194 and miR-196a with increasing levels (P < 0.0015) and miR-203, miR-205, miR-210 and miR-378 with decreasing levels (P < 0.0001). The subsequent analysis revealed four diagnostic miRNA signatures enabling to distinguish EM and BE [12 miRNAs, area under curve (AUC) = 0.971], EM and EAC (13 miRNAs, AUC = 1.0), BE without and BE with dysplasia (21 miRNAs, AUC = 0.856) and BE without dysplastic changes and BE with dysplasia together with EAC (2 miRNAs, AUC = 0.886). We suggest that miRNA expression profiling expands current knowledge in molecular pathology of Barrett's-based carcinogenesis and enables identification of molecular biomarkers for early detection of BE dysplasia and progression to EAC.

Urinary microRNAs as a new class of noninvasive biomarkers in oncology, nephrology, and cardiology

MicroRNAs (miRNAs) are small noncoding RNAs that posttranscriptionally regulate gene expression. In the last decade, number of evidences showing miRNAs contribution to the regulation of apoptosis, cellular proliferation, differentiation, and other important cellular processes is constantly growing. Specific miRNA expression signatures have been identified in variety of human cancers as well as pathologies of cardiovascular and urinary systems. Our chapter focuses on the potential of urinary miRNAs to serve as biomarkers in uro-oncology, nephrology, and cardiology. We discuss in detail recent knowledge about the origin of urinary miRNAs, their stability, quality control, and their utility as a potential new class of biomarkers in medicine. Finally, we summarize the studies focusing on detection and characterization of urinary miRNAs as potential biomarkers in urologic cancers, nephrology, and cardiology.

Risk Score based on microRNA expression signature is independent prognostic classifier of glioblastoma patients

Glioblastoma multiforme (GBM) is the most malignant primary brain tumor. The prognosis of GBM patients varies considerably and the histopathological examination is not sufficient for individual risk estimation. MicroRNAs (miRNAs) are small, non-coding RNAs that function as post-transcriptional regulators of gene expression and were repeatedly proved to play important roles in pathogenesis of GBM. In our study, we performed global miRNA expression profiling of 58 glioblastoma tissue samples obtained during surgical resections and 10 non-tumor brain tissues. The subsequent analysis revealed 28 significantly deregulated miRNAs in GBM tissue, which were able to precisely classify all examined samples. Correlation with clinical data led to identification of six-miRNA signature significantly associated with progression free survival [hazard ratio (HR) 1.98, 95% confidence interval (CI) 1.33-2.94, P < 0.001] and overa+ll survival (HR 2.86, 95% CI 1.91-4.29, P < 0.001). O(6)-methylguanine-DNA methyltransferase methylation status was evaluated as reference method and Risk Score based on six-miRNA signature indicated significant superiority in prediction of clinical outcome in GBM patients. Multivariate Cox analysis indicated that the Risk Score based on six-miRNA signature is an independent prognostic classifier of GBM patients. We suggest that the Risk Score presents promising prognostic algorithm with potential for individualized treatment decisions in clinical management of GBM patients.

Abstract 1492: Prediction of cancer progression in Barrett's esophagus patients using miRNA profiling

Background: Barrett's esophagus (BE) is a metaplastic disease with risk to develop esophageal adenocarcinoma (EAC). Current screening method for BE patients (endoscopy and biopsy) is discomfort, expensive and relatively risky for patients. Moreover, the procedure is complicated by subjective histopathological examination. Approximately only 2% of BE patients annually progress to adenocarcinoma. The aim of our study was to identify miRNA profiles in order to predict cancer progression in high-risk BE patients.

Methods and patients: FFPE samples were obtained from 68 patients (10 EAC, 4 high-grade and 21 low-grade dysplasia of esophagus, and 33 BE). There were 49 males and 19 females; median age was 58 years, range 27 - 97 years. Total RNA was purified from FFPE biopsy samples using Proteinase K treatment followed by RNeasy kit (Qiagen). Microarray analysis was performed using the GeneChip miRNA 3.0 Array (Affymetrix). The data were analyzed using “R” software and the Bioconductor package.

Results: In total, 68 GeneChip miRNA 3.0 Arrays were performed in 68 patients (8 poor quality arrays were excluded). Expression profiles of 1733 human miRNAs, 1658 human pre-miRNAs and 2216 human sno-RNAs and sca-RNAs were analyzed. In supervised clustering analysis we found 29 differentially expressed miRNAs, 7 pre-miRNAs and 9 sno-RNAs (p&lt;0.001 or logFC &lt;-2 or logFC &gt;2) in EAC patients compared to BE patients. One of the dominant findings was decreased expression of miR-22 in EAC samples, which is known to function as a tumor suppressor and histone deacetylase 4 regulator.

Conclusion: We have identified miRNA profiles allowing for better diagnostics of cancer progression in BE patients, which, however, will require further validation.

Acknowledgment: This work was financially supported by IGA MZ CR NT13585-3/202, IGA UP LF 2013_015, CZ.1.05/2.1.00/01.0030 and CZ.1.07/2.3.00/30.0004.

Citation Format: Josef Srovnal, Ondrej Slaby, Jiri Ehrmann, Jan Gregar, Lenka Radova, Michaela Sedlackova, Marian Hajduch. Prediction of cancer progression in Barrett's esophagus patients using miRNA profiling. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1492. doi:10.1158/1538-7445.AM2014-1492

Abstract 1496: MicroRNA signature associated with poor outcome of glioblastoma patients

Background: Glioblastoma multiforme (GBM) is the most frequently occurring primary malignant brain tumor with very poor prognosis, varying therapeutic response. Therefore, it is very important to find new biomarkers which can predict a clinical outcomes and help in treatment decisions. MicroRNAs (miRNAs) are small, non-coding RNAs that function as post-transcriptional regulators of gene expression and play key role in pathogenesis of wide range of cancer, including GBM. Aim of our study is to identify miRNA signature associated with the more aggressive phenotype of GBMs, which will enable sensitive prediction of clinical outcome in GBM patients under standard therapeutic protocols.

Methods: We determined the expression profile of 667 miRNAs in tumor tissues of 58 patients with primary GBM with completed concomitant chemoradiotherapy with temozolomide according to standard Stupp protocol and 12 non-malignant brain tissues obtained from patients with drug-resistant anteromedial temporal lobe epilepsy. Methylation status of MGMT promoter (methylation-specific HRM), isocitrate dehydrogenase (IDH1) status (immunohistochemistry) and co-deletion of 1p/19q (FISH) was also evaluated.

Results: We have confirmed frequencies of commonly used prognostic biomarkers in GBM patients (MGMT, IDH1, 1p/19q deletion), and observed significant correlation of MGMT methylation status, response to chemoradiotherapy with temozolomide and survival of GBM patients. We have identified specific signature of miRNAs diferentially expressed between GBM tissue and non-tumoral brain tissue from epilepsy surgeries (28 miRNAs, p&lt;10-10). We have confirmed some previous observations (e.g. up-regulation of miR-21, miR-155, down-regulation of miR-128a, miR-23a) and also identified miRNAs deregulated in GBM tissue which were observed for the first time (e.g. miR-220, miR-328, miR-888, miR-504). More importantly we have found miRNA signature (miR-224, miR-31, miR-454, miR-672, miR-885-5p, miR-432) significantly associated short progression-free survival (p&lt;10-6) and overall survival (p&lt;10-6).

Conclusions: These findings indicate that miRNAs play an important role in GBM pathogenesis and may serve not only as promising predictors of therapeutic outcome but also as potential therapeutic targets in GBM patients.

This work was supported by Grant NT13549-4/2012, NT13860 4/2012, NT11214-4/2010 and NT13514-4/2012 of the Czech Ministry of Health, MH CZ - DRO (MMCI, 00209805).

Citation Format: Jiri Sana, Radek Lakomy, Pavel Fadrus, Martin Smrcka, Pavel Slampa, Leos Kren, Marketa Hermanova, Marek Svoboda, Ondrej Slaby. MicroRNA signature associated with poor outcome of glioblastoma patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1496. doi:10.1158/1538-7445.AM2014-1496

Identification and functional screening of microRNAs highly deregulated in colorectal cancer

MicroRNAs (miRNAs) constitute a robust regulatory network with post-transcriptional regulatory efficiency for almost one half of human coding genes, including oncogenes and tumour suppressors. We determined the expression profile of 667 miRNAs in colorectal cancer (CRC) tissues and paired non-tumoural tissues and identified 42 differentially expressed miRNAs. We chose miR-215, miR-375, miR-378, miR-422a and miR-135b for further validation on an independent cohort of 125 clinically characterized CRC patients and for in vitro analyses. MiR-215, miR-375, miR-378 and miR-422a were significantly decreased, whereas miR-135b was increased in CRC tumour tissues. Levels of miR-215 and miR-422a correlated with clinical stage. MiR-135b was associated with higher pre-operative serum levels of CEA and CA19-9. In vitro analyses showed that ectopic expression of miR-215 decreases viability and migration, increases apoptosis and promotes cell cycle arrest in DLD-1 and HCT-116 colon cancer cell lines. Similarly, overexpression of miR-375 and inhibition of miR-135b led to decreased viability. Finally, restoration of miR-378, miR-422a and miR-375 inhibited G1/S transition. These findings indicate that miR-378, miR-375, miR-422a and miR-215 play an important role in CRC as tumour suppressors, whereas miR-135b functions as an oncogene; both groups of miRNA contribute to CRC pathogenesis.

Identification and functional screening of microRNAs highly deregulated in colorectal cancer

MicroRNAs (miRNAs) constitute a robust regulatory network with post-transcriptional regulatory efficiency for almost one half of human coding genes, including oncogenes and tumour suppressors. We determined the expression profile of 667 miRNAs in colorectal cancer (CRC) tissues and paired non-tumoural tissues and identified 42 differentially expressed miRNAs. We chose miR-215, miR-375, miR-378, miR-422a and miR-135b for further validation on an independent cohort of 125 clinically characterized CRC patients and for in vitro analyses. MiR-215, miR-375, miR-378 and miR-422a were significantly decreased, whereas miR-135b was increased in CRC tumour tissues. Levels of miR-215 and miR-422a correlated with clinical stage. MiR-135b was associated with higher pre-operative serum levels of CEA and CA19-9. In vitro analyses showed that ectopic expression of miR-215 decreases viability and migration, increases apoptosis and promotes cell cycle arrest in DLD-1 and HCT-116 colon cancer cell lines. Similarly, overexpression of miR-375 and inhibition of miR-135b led to decreased viability. Finally, restoration of miR-378, miR-422a and miR-375 inhibited G1/S transition. These findings indicate that miR-378, miR-375, miR-422a and miR-215 play an important role in CRC as tumour suppressors, whereas miR-135b functions as an oncogene; both groups of miRNA contribute to CRC pathogenesis.

Identification of microRNAs regulated by isothiocyanates and association of polymorphisms inside their target sites with risk of sporadic colorectal cancer

Sporadic colorectal cancer (CRC) is a typical multifactorial disease. Isothiocyanates (ITC) have been recently shown to inhibit development of CRC in many experimental models. MicroRNAs (miRNAs) are short noncoding RNAs that posttranscriptionally regulate gene expression through binding to 3' untranslated regions (3'UTR) of target mRNAs. MiRNAs are regulated by natural agents, ITCs included. In our study, using global expression profiling based on TaqMan Low-Density Arrays, we identified 3 common miRNAs (miR-155, miR-23b, miR-27b) regulated by ITCs (sulforaphane, iberin) in colonic epithelial cell lines NCM460 and NCM356. In silico predictions allowed us to find 9 relevant single nucleotide polymorphisms (SNPs) localized within the 3'UTRs of genes (AGTR1, TNFAIP2, PRKCB, HSPA9, RABGAP1, DICER1, ADAM19, VWA5A, and SIRT5) targeted by these ITC-related miRNAs. Finally, we observed that homozygous CC genotype of DICER1, rs1057035, was significantly associated with decreased risk of CRC (odds ratio = 0.49; 95% confidence interval: 0.25-0.95, P = 0.036) when compared to TT homozygote genotype; also, the C allele tended to have a protective effect (P = 0.072). This study showed that miRNAs could be involved in chemoprotective effects of natural agents; their function alteration through SNPs in their binding sites and flanking regions presents a new class of CRC risk factors.

Circulating serum microRNAs as novel diagnostic and prognostic biomarkers for multiple myeloma and monoclonal gammopathy of undetermined significance

Multiple myeloma still remains incurable in the majority of cases prompting a further search for new and better prognostic markers. Emerging evidence has suggested that circulating microRNAs can serve as minimally invasive biomarkers for multiple myeloma and monoclonal gammopathy of undetermined significance. In this study, a global analysis of serum microRNAs by TaqMan Low Density Arrays was performed, followed by quantitative real-time PCR. The analyses revealed five deregulated microRNAs: miR-744, miR-130a, miR-34a, let-7d and let-7e in monoclonal gammopathy of undetermined significance, newly diagnosed and relapsed multiple myeloma when compared to healthy donors. Multivariate logistical regression analysis showed that a combination of miR-34a and let-7e can distinguish multiple myeloma from healthy donors with a sensitivity of 80.6% and a specificity of 86.7%, and monoclonal gammopathy of undetermined significance from healthy donors with a sensitivity of 91.1% and a specificity of 96.7%. Furthermore, lower levels of miR-744 and let-7e were associated with shorter overall survival and remission of myeloma patients. One-year mortality rates for miR-744 and let-7e were 41.9% and 34.6% for the 'low' expression and 3.3% and 3.9% for the 'high' expression groups, respectively. Median time of remission for both miR-744 and let-7e was approximately 11 months for the 'low' expression and approximately 47 months for the 'high' expression groups of myeloma patients These data demonstrate that expression patterns of circulating microRNAs are altered in multiple myeloma and monoclonal gammopathy of undetermined significance and miR-744 with let-7e are associated with survival of myeloma patients.

Circulating miR-17-3p, miR-29a, miR-92a and miR-135b in serum: Evidence against their usage as biomarkers in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the leading causes of cancer-related death in the world. Therefore, there is a high demand for cost-effective and non-invasive biomarkers that would enable an early detection of asymptomatic and curable disease with high sensitivity and specificity.

OBJECTIVE

The main objective of this study was to investigate the potential of circulating miRNAs as biomarkers of CRC.

METHODS

Total RNA enriched for small RNAs was isolated from 100~sera of patients with CRC and 30 sera of healthy donors. The expression levels of miR-17-3p, miR-29a, miR-92a and miR-135b were determined using quantitative real-time PCR. The average expression levels of particular miRNAs were normalized to miR-16 levels and statistically evaluated.

RESULTS

Using Mann-Whitney U test, no significant differences were observed in miR-17-3p (P=0.18), miR-29a (P=0.14) and miR-92a (P=0.60) levels between sera of CRC patients and controls. The levels of miR-135b in serum were too low to be quantified accurately. Subsequently, we tried to correlate expression levels of analyzed miRNAs to clinical-pathological features of CRC patients. Only levels of mir-29a were correlated with the clinical stage (P=0.04). Expression levels of the other miRNAs were correlated neither with the clinical stage, nor with the grade.

CONCLUSIONS

Interestingly, our results are contradictory to previous studies performed on the CRC patients from Chinese population, providing an evidence against usage of serum miR-17-3p, miR-29a, miR-92a and miR-135b as new biomarkers for early detection of CRC.

Urine microRNAs as potential noninvasive biomarkers in urologic cancers

Micro-ribonucleic acids (miRNAs) are small noncoding RNAs that posttranscriptionally regulate gene expression. The ability of miRNAs to inhibit translation of oncogenes and tumor suppressors implies that they may be involved in carcinogenesis. Our review focuses on the potential of urinary miRNAs to serve as biomarkers of urologic cancers. We discuss in detail the recent knowledge about the origin of urinary miRNAs, their stability, quality control, and their utility as a potential new class of biomarkers in urologic cancer. Finally, we summarize the studies focusing on detection and characterization of urinary miRNAs as potential biomarkers in bladder, prostate, and kidney cancers.

MicroRNAs targeting EGFR signalling pathway in colorectal cancer

MicroRNAs (miRNAs) are short, 18-25-nucleotide long, non-coding single-stranded RNAs, which are capable to regulate gene expression on post-transcriptional level through binding to their target protein-encoding mRNAs. miRNAs regulate individual components of multiple oncogenic pathways. One of them is epidermal growth factor receptor (EGFR) signalling pathway that regulates cell proliferation, differentiation, migration, angiogenesis and apoptosis. All these processes are deregulated in colorectal cancer (CRC). Moreover, EGFR has been validated as the therapeutic target in CRC, and monoclonal antibodies cetuximab and panitumumab are used in the therapy of patients with metastatic CRC. Because of the extensive involvement of miRNAs in the regulation of EGFR signalling, it seems they could also serve as promising predictive biomarkers to anti-EGFR therapy. In this review, we summarize current knowledge about miRNAs targeting EGFR signalling pathway, their functioning in CRC pathogenesis and potential usage as biomarkers.

Abstract 4172: MiR-215 expression in tumor tissue and in vitro effects of its replacement in colorectal cancer

Background: MicroRNAs (miRNAs) constitute a robust regulatory network with post-transcriptional regulatory efficiency for almost one half of human coding genes, including oncogenes and tumor suppressors.

Methods: We determined the expression profile of 667 miRNAs in colorectal cancer (CRC) tissues and paired non-tumoral tissues and identified 42 differentially expressed miRNAs. One of the most significantly altered miRNAs was miR-215, significantly down-regulated in tumor tissue. We chose miR-215 for further validation on an independent cohort of 125 clinically characterized CRC patients and for in vitro functional studies on DLD1, HCT116 and HT29 cell lines.

Results: MiR-215 was proved to be significantly decreased in CRC tumor tissues (p&lt;0.0001) and to be negatively correlated with clinical stage (p&lt;0.0001) and tumor grade (p=0.04). In vitro analyses showed that ectopic expression of miR 215 decreases viability in DLD1 (p=0.05) and HCT116 (p=0,05) cells, increases apoptosis in HCT116 (p=0.005), promotes cell cycle arrest (inhibited G1/S transition) in HCT-116 colon cancer cells (p=0.01) and decreases migration in DLD1 (p=0.05) and HT-29 cells (p=0.05). We further confirmed transcription factor HOXB9 as direct target of miR-215 on the mRNA and protein level.

Conclusions: These findings indicate that miR 215 play an important role in CRC as tumor suppressor and contributes to CRC pathogenesis.

Supported by Internal Grant Agency of Czech Ministry of Health, grant numbers: NT13549-4/2012 a NT13860 4/2012.

Citation Format: Petra Faltejskova, Marek Svoboda, Jitka Mlcochova, Klara Srutova, Pavel Fabian, Rostislav Vyzula, Ondrej Slaby. MiR-215 expression in tumor tissue and in vitro effects of its replacement in colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4172. doi:10.1158/1538-7445.AM2013-4172

MicroRNAs involved in chemo- and radioresistance of high-grade gliomas

High-grade gliomas (HGGs) are malignant primary brain tumors of glial cell origin. Despite optimal course of treatment, including maximal surgical resection followed by adjuvant chemo- and/or radiotherapy, the prognosis still remains poor. The main reason is the commonly occurring chemo- and radioresistance of these tumors. In recent years, several signaling pathways, especially PI3K/AKT and ATM/CHK2/p53, have been linked to the resistance of gliomas. Moreover, additional studies have shown that these pathways are significantly regulated by microRNAs (miRNAs), short endogenous RNA molecules that modulate gene expression and control many biological processes including apoptosis, proliferation, cell cycle, invasivity, and angiogenesis. MiRNAs are not only highly deregulated in gliomas, their expression signatures have also been shown to predict prognosis and therapy response. Therefore, they present promising biomarkers and therapeutic targets that might overcome the resistance to treatment and improve prognosis of glioma patients. In this review, we summarize the current knowledge of the functional role of miRNAs in gliomas resistance to chemo- and radiotherapy.

MicroRNA expression profile associated with response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer patients

Background

Rectal cancer accounts for approximately one third of all colorectal cancers (CRC), which belong among leading causes of cancer deaths worldwide. Standard treatment for locally advanced rectal cancer (cT3/4 and/or cN+) includes neoadjuvant chemoradiotherapy with fluoropyrimidines (capecitabine or 5-fluorouracil) followed by radical surgical resection. Unfortunately, a significant proportion of tumors do not respond enough to the neoadjuvant treatment and these patients are at risk of relapse. MicroRNAs (miRNAs) are small non-coding RNAs playing significant roles in the pathogenesis of many cancers including rectal cancer. MiRNAs could present the new predictive biomarkers for rectal cancer patients.

Methods

We selected 20 patients who underwent neoadjuvant chemoradiotherapy for advanced rectal cancer and whose tumors were classified as most sensitive or resistant to the treatment. These two groups were compared using large-scale miRNA expression profiling.

Results

Expression levels of 8 miRNAs significantly differed between two groups. MiR-215, miR-190b and miR-29b-2* have been overexpressed in non-responders, and let-7e, miR-196b, miR-450a, miR-450b-5p and miR-99a* have shown higher expression levels in responders. Using these miRNAs 9 of 10 responders and 9 of 10 non-responders (p < 0.05) have been correctly classified.

Conclusions

Our pilot study suggests that miRNAs are part of the mechanisms that are involved in response of rectal cancer to the chemoradiotherapy and that miRNAs may be promising predictive biomarkers for such patients. In most miRNAs we identified (miR-215, miR-99a*, miR-196b, miR-450b-5p and let-7e), the connection between their expression and radioresistance or chemoresistance to inhibitors of thymidylate synthetase was already established.