miR-21 In Tumors Research Articles

Mesyl phosphoramidate backbone modified antisense oligonucleotides targeting miR-21 with enhanced in vivo therapeutic potency

The design of modified oligonucleotides that combine in one molecule several therapeutically beneficial properties still poses a major challenge. Recently a new type of modified mesyl phosphoramidate (or µ-) oligonucleotide was described that demonstrates high affinity to RNA, exceptional nuclease resistance, efficient recruitment of RNase H, and potent inhibition of key carcinogenesis processes in vitro. Herein, using a xenograft mouse tumor model, it was demonstrated that microRNA miR-21-targeted µ-oligonucleotides administered in complex with folate-containing liposomes dramatically inhibit primary tumor growth via long-term down-regulation of miR-21 in tumors and increase in biosynthesis of miR-21-regulated tumor suppressor proteins. This antitumoral effect is superior to the effect of the corresponding phosphorothioate. Peritumoral administration of µ-oligonucleotide results in its rapid distribution and efficient accumulation in the tumor. Blood biochemistry and morphometric studies of internal organs revealed no pronounced toxicity of µ-oligonucleotides. This new oligonucleotide class provides a powerful tool for antisense technology.

Hypomethylation Causes MIR21 Overexpression in Tumors

miR-21 is an oncogenic microRNA (miRNA) that is upregulated in many solid tumors. However, the effect of MIR21 hypomethylation on miR-21 expression in tumors and the mechanism of miR-21 DNA demethylation remain unclear. In this study, we confirmed that the expression of miR-21 was significantly increased in multiple tumors. We analyzed eight types of cancer, including breast cancer (BRCA), lung adenocarcinoma (LUAD), renal and renal clear cell carcinoma (KIRC), bladder urothelial carcinoma (BLCA), hepatocellular carcinoma (LIHC), lung squamous cell cancer (LUSC), renal papillary cell carcinoma (KIRP), and pancreatic adenocarcinoma (PAAD). MIR21 DNA methylation levels were elevated in these cancers. CpG loci located approximately 200 bp upstream of the transcription initiation site strongly affect MIR21 expression. We also confirmed MIR21 hypomethylation by pyrosequencing of fresh clear cell renal cell carcinoma (ccRCC) samples. Demethylating agent was proved to increase hsa-miR-21-5p level in HEK293T cells, while knockdown of DNA demethylases TET3 and TDG decreased MIR21 expression. In addition, we showed that the cg02515217 CpG locus in MIR21 promoter was a conserved binding site of transcription factors CEBPB, MEIS3, and TEAD4, which were co-expressed with miR-21 in tumors. These observations identified that gene hypomethylation regulated the expression of MIR21 in tumors.

Comprehensive transcriptomic analyses of tissue, serum, and serum exosomes from hepatocellular carcinoma patients

BackgroundThe expression of microRNAs (miRNAs) is a promising prognostic and diagnostic tool in hepatocellular carcinoma (HCC). Here we performed small RNA sequencing (sRNA-seq) of tissue, serum and serum exosomes to investigate changes in miRNA expression between the different sample types and correlated the expression with clinical parameters. We also performed gene expression arrays on tumor and normal tissue.ResultsPaired tissue, serum and serum exosomes sequencing revealed consistent positive correlation of miR-21 between serum exosomes and tumor tissue, indicating that miR-21 could be exported from tissue to circulation via exosomes. We found that let-7 miRNAs are generally upregulated in serum exosomes compared to whole serum, indicating that these miRNAs could be preferentially loaded into exosomes. Comparing serum from HCC patients with serum from healthy individuals revealed a global increase of miRNAs in serum from HCC patients, including an almost 4-fold increase of several miRNAs, including the liver-specific miR-122. When correlating miRNA expression with clinical parameters we detected significant association between hepatitis B virus (HBV) infection and miR-122 in serum as well as several serum and tissue-miRNAs that correlated with surgery type. We found that miR-141 and miR-146 correlated with cirrhosis in tumor tissue and normal tissue, respectively. Finally, high expression of miR-21 in tumors were associated with poor survival. Focusing on gene expression we found several significant messenger RNAs (mRNAs) between tumor and normal tissue and a Gene Ontology (GO) analysis revealed that these changes were mainly related to cell cycle and metabolism. Further, we detected mRNAs that correlated with cirrhosis and HBV infection in tissue. Finally, GO analysis of predicted targets for miRNAs down-regulated in tumor found that these were enriched for functions related to collagen synthesis.ConclusionsOur combined data point to altered miRNA and mRNA expression contributing to both generally impaired lipid metabolism and increased cell proliferation and a miRNA-driven increase in collagen synthesis in HCC. Our results further indicate a correlation in miRNA expression between exosomes, serum, and tissue samples suggesting export from tumors via exosomes. This correlation could provide a basis for a more tumor-specific miRNA profile in serum.

Clinical significance of tumor miR-21, miR-221, miR-143, and miR-106a as biomarkers in patients with osteosarcoma.

To investigate the expression of miR-21, miR-221, miR-143, and miR-106a in patients' osteosarcoma samples, and to explore the correlation between these microRNAs (miRNAs) and the clinical stage of osteosarcoma. RNA was extracted from tumor and tumor-adjacent normal bone tissues from 94 patients with osteosarcoma. RNA reverse-transcription was carried out using an miRNA reverse transcription kit. The levels of miR-21, miR-221, miR-143, and miR-106a in osteosarcoma and normal bone tissues were analyzed by real-time polymerase chain reaction using SYBR Premix Ex Taq™II. The expression levels of miR-21, mirR-221, and miR-106a were significantly higher in 90.42%, 84.04%, and 92.55 % of the osteosarcoma samples compared to the adjacent normal tissues (P<0.05), respectively. While the expression of miR-143 was significantly lower compared to the adjacent normal tissues (P <0.05). Moreover, the expression levels of miR-21 and miR-221 were positively correlated with the Enneking clinical stage and the presence of lung metastasis (P <0.05), while the expression levels of miR-143 and miR-106a showed a significant inverse and direct correlation respectively, with the tumor grade. The upregulation of miR-21, miR-221, and miR-106a, as well as the down-regulation of miR-143 were correlated with the pathological stage, tumor grade, and lung metastasis. Therefore, the levels of these miRNAs can serve as potential biomarkers for the early diagnosis of osteosarcoma, and can be used as potential therapeutic targets.

Abstract 4741: Biomarker significance of plasma and tumor miR-21, miR-221, and miR-106a in pediatric osteosarcoma

Abstract Osteosarcoma is the most common malignant bone tumor in children and young adults. Despite the use of surgery and multi-agent chemotherapy, osteosarcoma patients who respond poorly towards chemotherapy or develop relapses have a dismal outcome. Identification of biomarkers for active disease may help to monitor tumor burden, detect early relapses, and predict prognosis in these patients, so that they can be treated as early as possible to improve their survival. In this study, we examined if circulating microRNAs (miRNAs) can be used as biomarkers in osteosarcoma patients. We performed genome-wide miRNA profiling on a discovery cohort of OS plasma samples (n=32) collected from the Texas Children’s Hospital. A total of 56 miRNAs were upregulated and 164 miRNAs were downregulated in osteosarcoma samples when compared to normal plasma samples (n=8). miRNA-21, miR-221 and miRNA-106a were selected for further validation based on their known biological importance. We showed that all three circulating miRNAs were expressed significantly higher in OS samples (n=29) than normal samples (n=17) in an independent cohort obtained from the Children’s Oncology Group. Furthermore, we demonstrated that miR-21 was expressed significantly higher in osteosarcoma tumors (n=89) compared with normal bone controls. More importantly, lower expressions of miR-21 and miR-221, but not miR-106a, significantly correlated with a poor outcome. In conclusion, our results indicate that miR-21, miR-221 and miR-106a are elevated in the circulation of osteosarcoma patients, whereas tumor expressions of miR-21 and miR-221 are prognostically significant. Further investigation of the miRNAs may lead to a better prognostic method and potential miRNA therapeutics for osteosarcoma. Citation Format: Manjula Nakka, Wendy Allen-Rhoades, Yiting Li, Aaron Kelly, Jianhe Shen, Aaron Taylor, Donald A. Barkauskas, Jason Yustein, Irene Andrulis, Jay Wunder, Richard Gorlick, Paul Meltzer, Ching Lau, Tsz-Kwong Man. Biomarker significance of plasma and tumor miR-21, miR-221, and miR-106a in pediatric osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4741. doi:10.1158/1538-7445.AM2017-4741

Biomarker significance of plasma and tumor miR-21, miR-221, and miR-106a in osteosarcoma.

Osteosarcoma is the most common malignant bone tumor in children and young adults. Despite the use of surgery and multi-agent chemotherapy, osteosarcoma patients who have a poor response to chemotherapy or develop relapses have a dismal outcome. Identification of biomarkers for active disease may help to monitor tumor burden, detect early relapses, and predict prognosis in these patients. In this study, we examined whether circulating miRNAs can be used as biomarkers in osteosarcoma patients. We performed genome-wide miRNA profiling on a discovery cohort of osteosarcoma and control plasma samples. A total of 56 miRNAs were upregulated and 164 miRNAs were downregulated in osteosarcoma samples when compared to control plasma samples. miR-21, miR-221 and miR-106a were selected for further validation based on their known biological importance. We showed that all three circulating miRNAs were expressed significantly higher in osteosarcoma samples than normal samples in an independent cohort obtained from the Children’s Oncology Group. Furthermore, we demonstrated that miR-21 was expressed significantly higher in osteosarcoma tumors compared with normal bone controls. More importantly, lower expressions of miR-21 and miR-221, but not miR-106a, significantly correlated with a poor outcome. In conclusion, our results indicate that miR-21, miR-221 and miR-106a were elevated in the circulation of osteosarcoma patients, whereas tumor expressions of miR-21 and miR-221 are prognostically significant. Further investigation of these miRNAs may lead to a better prognostic method and potential miRNA therapeutics for osteosarcoma.

173PD MicroRNA MIR21, T cells, and PTGS2 expression in

Background Prostaglandin-endoperoxide synthase 2 (PTGS2, cyclooxygenase-2) produces inflammatory mediator prostaglandin E2 (PGE2), and contributes to suppresses antitumorT-cell-mediated immunity. PTGS2-driven inflammatory responses can induce tumorexpressionof microRNAMIR21 (miR-21) thatcanincreaselocalPGE2levelby downregulatingPGE2-metabolizingenzymes. Thus,wehypothesizedthattheprognostic associationoftumorMIR21 expressionlevelincolorectalcarcinomamightdependon PTGS2 expression and that tumor MIR21 expression might be inversely associated with T- cell density in colorectal carcinoma tissue. Methods Utilizing 765 rectal and colon cancer specimens in the Nurses' Health Study and the Health Professionals Follow-up Study, we measured MIR21 expression by quantitative reverse-transcription PCR, and PTGS2 expression by immunohistochemistry. Densities of CD3+, CD8+, CD45RO (pTpRC)+ and FOXP3+ cells in tumor tissue were determined by tissue microarray immunohistochemistry and computer-assisted image analysis. Multivariable analyses were conducted to assess the statistical interaction between MIR21 and PTGS2 in colorectal cancer-specific survival analysisandtheassociationofMIR21 expression withT-celldensity, controlling for potential confounders including microsatellite instability, CpG island methylator phenotype, LINE-1 methylation level, and KRAS, BRAF, and PIK3CA mutations. Results The association between MIR21 expression and colorectal cancer-specific mortality was statistically significant in PTGS2-high cancers (multivariable hazard ratio ofthehighestvs. lowestquartileofMIR21, 2.28;95%confidenceinterval, 1.42 to3.67; Ptrend= 0.0004) butnotinPTGS2-absent/lowcancers (Ptrend= 0.22;Pinteraction= 0.0004). Tumor MIR21 expression was inversely associated with densities of CD3+ and CD45RO+ cells (Pt rend < 0.0005). Conclusions:Ourdatasupportapossibleroleoftumorepigeneticderegulationbynon- coding RNA in suppressing antitumor T-cell-mediated immune response, and suggest MIR21 as a potential target for immunotherapy and treatment in colorectal cancer. Legal entity responsible for the study USA National Institutes of Health (NIH) Funding USA National Institutes ofHealth (NIH) Disclosure All authors have declared no conflicts ofinterest.

MicroRNA MIR21 (miR-21) and PTGS2 Expression in Colorectal Cancer and Patient Survival.

Prostaglandin-endoperoxide synthase 2 (PTGS2, cyclooxygenase-2; a target of aspirin) produces inflammatory mediator prostaglandin E2 (PGE2), and contributes to colorectal neoplasia development. PTGS2-driven inflammatory responses can induce tumor expression of microRNA MIR21 (miR-21) that can increase local PGE2 level by downregulating PGE2-metabolizing enzymes. We hypothesized that the prognostic association of tumor MIR21 expression level in colorectal carcinoma might depend on inflammatory tumor microenvironment and be stronger in tumors expressing high-level PTGS2. Utilizing 765 rectal and colon cancer specimens in the Nurses' Health Study and the Health Professionals Follow-up Study, we measured MIR21 expression by quantitative reverse transcription PCR, and PTGS2 expression by immunohistochemistry. Cox proportional hazards regression model was used to assess statistical interaction between MIR21 and PTGS2 in colorectal cancer-specific survival analysis, controlling for potential confounders including microsatellite instability, CpG island methylator phenotype, LINE-1 methylation level, and KRAS, BRAF, and PIK3CA mutations. Tumor MIR21 expression level was associated with higher colorectal cancer-specific mortality (Ptrend = 0.029), and there was a statistically significant interaction between MIR21 and PTGS2 (Pinteraction = 0.0004). The association between MIR21 expression and colorectal cancer-specific mortality was statistically significant in PTGS2-high cancers (multivariable hazard ratio of the highest vs. lowest quartile of MIR21, 2.28; 95% confidence interval, 1.42-3.67; Ptrend = 0.0004) but not in PTGS2-absent/low cancers (Ptrend = 0.22). MIR21 expression level in colorectal carcinoma is associated with worse clinical outcome, and this association is stronger in carcinomas expressing high-level PTGS2, suggesting complex roles of immunity and inflammation in tumor progression. Clin Cancer Res; 22(15); 3841-8. ©2016 AACR.

Quantitative Detection of MicroRNA in One Step via Next Generation Magnetic Relaxation Switch Sensing.

One-step, quantitative and rapid detection of microRNA (miRNA) in tumor cells or tissues can provide critical information for clinical diagnosis and cancer treatment. In this work, we develop a magnetic relaxation switch sensing (MRS)-based miRNA sensor using magnetic microparticle (1 μm in diameter, MM1000)-DNA probe-magnetic nanoparticle (30 nm in diameter, MN30) conjugates (MM1000-DNA-MN30). In the presence of target miRNA, DSN enzyme selectively cleaves the DNA tether after miRNA/DNA hybridization to release MN30 and leaves the miRNA intact to lead to the declustering of more MN30 than before. In contrast to conventional MRS by measuring the change of transverse relaxation time (ΔT2) induced by the aggregation or dissociation of magnetic particles in the presence of target, we use the cleaved MN30 from conjugates as the direct readout of ΔT2, which is more sensitive and stable. This MRS-based assay allows for one-step detection of 5 fM of miR-21 in urine samples, quantification of miR-21 from 100 cancer cells, and differentiation of the expression of miR-21 in tumor and surrounding tissues. The merits of this assay, rapidity, ability for quantitation, high sensitivity, and one-step operation, ensure a promising future in diagnostic technology.

MicroRNA MIR21 and T Cells in Colorectal Cancer.

The complex interactions between colorectal neoplasia and immune cells in the tumor microenvironment remain to be elucidated. Experimental evidence suggests that microRNA MIR21 (miR-21) suppresses antitumor T-cell-mediated immunity. Thus, we hypothesized that tumor MIR21 expression might be inversely associated with T-cell density in colorectal carcinoma tissue. Using 538 rectal and colon cancer cases from the Nurses' Health Study and the Health Professionals Follow-up Study, we measured tumor MIR21 expression by a quantitative reverse-transcription PCR assay. Densities of CD3(+), CD8(+), CD45RO (PTPRC)(+), and FOXP3(+) cells in tumor tissue were determined by tissue microarray immunohistochemistry and computer-assisted image analysis. Ordinal logistic regression analysis was conducted to assess the association of MIR21 expression (ordinal quartiles as a predictor variable) with T-cell density (ordinal quartiles as an outcome variable), adjusting for tumor molecular features, including microsatellite instability; CpG island methylator phenotype; KRAS, BRAF, and PIK3CA mutations; and LINE-1 methylation. We adjusted the two-sided α level to 0.012 for multiple hypothesis testing. Tumor MIR21 expression was inversely associated with densities of CD3(+) and CD45RO(+) cells (Ptrend < 0.0005). The multivariate odds ratio of the highest versus lowest quartile of MIR21 for a unit increase in quartile categories of CD3(+) or CD45RO(+) cells was 0.44 [95% confidence interval (CI), 0.28 to 0.68] or 0.41 (95% CI, 0.26-0.64), respectively. Our data support a possible role of tumor epigenetic deregulation by noncoding RNA in suppressing the antitumor T-cell-mediated adaptive immune response and suggest MIR21 as a potential target for immunotherapy and prevention in colorectal cancer.

Abstract 534: MicroRNA-143 is a putative predictive biomarker for 5-FU-based chemotherapy in patients with metastatic colorectal cancer

Abstract Background: Approximately half of the colorectal cancer (CRC) patients develop metastatic disease, either at diagnosis or during follow-up. 5-FU-based chemotherapy forms the backbone of treatment in these patients. However, the response to this therapy varies between individuals. Therefore, an important challenge in CRC research is to identify biomarkers that are predictive of this response. MicroRNAs are short RNAs that post-transcriptionally regulate the gene expression of many genes. MicroRNA levels are frequently altered in cancer, and can affect expression of genes that modulate tumorigenesis. Objective: In this study, we explore the potential of microRNAs, and the microRNA producing protein Dicer, as biomarkers that can predict chemo-sensitivity in patients with metastatic colorectal cancer. Methods: We analyzed the levels of a selected panel of 22 miRNAs and the Dicer protein in primary CRC tumors from patients enrolled in the CAIRO study (a phase III study of the Dutch Colorectal Cancer Group). MiRNA levels were determined with Taqman microRNA assays and Dicer level with immunohistochemistry. Correlation between the expression status of microRNAs or Dicer in primary tumors and the progression free survival (PFS) were investigated. In addition, we evaluated correlations between Dicer and miRNA levels. Results: Variable Dicer intensities were observed among the analyzed samples, but there was no significant association between Dicer levels and PFS. In addition, no clear correlation between Dicer and miRNA levels could be identified. We especially detected higher expression of miR-31 and miR-21 in tumors compared to matched normal tissue, whereas miR-137 and miR-215 were lower expressed. Interestingly, miR-143 expression was reduced in a subset of the primary CRC tumors, and this differential expression showed a relationship with PFS. The group with reduced miR-143 expression showed higher PFS. The median PFS for patients with reduced, neutral and increased miR-143 expression was 261, 167 and 142 days, respectively (p-value log-rank test=0.018). Conclusion: The expression level of miR-143 may have clinical utility as a biomarker for response to 5-FU-based chemotherapy. These findings warrant further studies to investigate the relationship between miR-143 expression and 5-FU. Citation Format: Femke Simmer, Jeroen Dijkstra, Sabine Venderbosch, Claudius Faber, Leonie Mekenkamp, Miriam Koopman, Ton de Haan, Cornelis Punt, Iris Nagtegaal. MicroRNA-143 is a putative predictive biomarker for 5-FU-based chemotherapy in patients with metastatic colorectal cancer. [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 534. doi:10.1158/1538-7445.AM2014-534

High tumor cell expression of microRNA-21 in node positive non-small cell lung cancer predicts a favorable clinical outcome

BackgroundMicroRNA (miR)-21 has been revealed as an oncogene in cancer development, and is one of the miRNAs closely connected to angiogenesis. We aimed to explore the impact of miR-21 expression in both tumor and stromal compartments of non-small cell lung cancer (NSCLC), and correlations between miR-21 and angiogenic protein markers.MethodsFrom 335 unselected stage I to IIIA NSCLC carcinomas, duplicate tumor and tumor-associated stromal cores were collected in tissue microarrays (TMAs). In situ hybridization (ISH) was used to detect the expression of miR-21 separately in tumor cells and stromal cells of the tumor, and immunohistochemistry (IHC) was used to detect the expression of the protein markers protein kinase B (Akt), phosphatidylinositol-3-kinase (PI3K), hypoxia induced factor 1 (HIF1α) and vascular endothelial growth factor-A (VEGF-A).ResultsIn univariate analyses, high tumor cell expression of miR-21 in patients with lymph node metastasis was a positive prognostic factor (P = 0.024). High stromal miR-21 expression had a negative prognostic impact (P = 0.022). In the multivariate analysis, low tumor mir-21 expression in node positive patients was an independent adverse prognostic factor (HR 2.03, CI 95% 1.09-3.78, P = 0.027).ConclusionsIn patients with lymph node metastasis, miR-21 expression in tumor cells is an independent positive prognostic factor. High stromal miR-21 expression is a negative prognostic factor.

Co-regulated expression of TGF-β Variants and miR-21 in bladder cancer.

To investigate a potential alteration in the expression levels of transforming growth factor β (TGF-β) and miR-21 in bladder cancer tissues. Using real-time polymerase chain reaction (PCR) method, we examined a potential correlated expression of miR-21 and TGF-β variants in 30 bladder tumors and their marginal/non-tumor biopsy specimens obtained from the same patients. Our data revealed a significant down-regulation of TGF-β variants (P = .03) along with a non-significant alteration in the expression of miR-21 in tumor vs. non-tumor samples. However, in contrast to low-grade tumors, the expression of miR-21 was upregulated in high-grade ones, and the expression level can efficiently discriminate low-grade tumors from high-grade ones (P = .03). In accordance to the observed similarity between TGF-β variants and miR-21 gene expression alterations in bladder tumors, treating 5637 bladder cancer cell line with TGF-β recombinant protein caused a significant upregulation of miR-21. The later finding further confirmed a correlated expression of TGF-β and miR-21 in bladder tumors.

566. A Novel Oncolytic HSV Design Based on the Common Over-Expression of miR-21 in Tumors

566. A Novel Oncolytic HSV Design Based on the Common Over-Expression of miR-21 in Tumors

High expression of serum miR-21 and tumor miR-200c associated with poor prognosis in patients with lung cancer

Serum microRNAs have been identified as potential cancer biomarkers. However, the detailed mechanism by which expression of microRNAs contributes to the development and diagnosis of NSCLC remains unknown. This study was to identify specific miRNAs for diagnosing or predicting the prognosis of NSCLC patients and their correlation between miRNA expression in tissues and serums. Six matched cancer and noncancerous tissues from NSCLC patients were analyzed by miRNA microarray. Among these, three miRNAs (miR-21, miR-141, and miR-200c) were examined in 70 NSCLC paired samples (cancer, normal tissue, and serum) and 44 serum samples of normal volunteers by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Consisting with the microarray results, the expression levels of miR-21, miR-141, and miR-200c in NSCLC were higher than those in normal tissues. While the level of serum miR-21 was increased in cancer patients as compared with that in normal counterpart, expression of miR-141 and miR-200c showed lower levels in serums from cancer patients. Overexpression of serum miR-21 was strongly associated with lymph node metastasis and advanced clinical stage of NSCLC. Finally, log-rank and Cox regression tests demonstrated that high expressions of tumor miR 21 and miR-200c or serum miR-21 were associated with a poor survival in NSCLC patients. Our results suggest that tumor miR-21, miR-141, miR-200c, and serum miR-21 may be potential novel biomarkers for the diagnosis of NSCLC. In addition, this study, for the first time, identifies a significant role of the tumor miR-200c played in predicting prognosis in patients with NSCLC.