Overexpression Of microRNA-21 Research Articles

MiR-21 Is Induced by Hypoxia and Down-Regulates RHOB in Prostate Cancer.

Tumour hypoxia is a well-established contributor to prostate cancer progression and is also known to alter the expression of several microRNAs. The over-expression of microRNA-21 (miR-21) has been consistently linked with many cancers, but its role in the hypoxic prostate tumour environment has not been well studied. In this paper, the link between hypoxia and miR-21 in prostate cancer is investigated. A bioinformatic analysis of The Cancer Genome Atlas (TCGA) prostate biopsy datasets shows the up-regulation of miR-21 is significantly associated with prostate cancer and clinical markers of disease progression. This up-regulation of miR-21 expression was shown to be caused by hypoxia in the LNCaP prostate cancer cell line in vitro and in an in vivo prostate tumour xenograft model. A functional enrichment analysis also revealed a significant association of miR-21 and its target genes with processes related to cellular hypoxia. The over-expression of miR-21 increased the migration and colony-forming ability of RWPE-1 normal prostate cells. In vitro and in silico analyses demonstrated that miR-21 down-regulates the tumour suppressor gene Ras Homolog Family Member B (RHOB) in prostate cancer. Further a TCGA analysis illustrated that miR-21 can distinguish between different patient outcomes following therapy. This study presents evidence that hypoxia is a key contributor to the over-expression of miR-21 in prostate tumours, which can subsequently promote prostate cancer progression by suppressing RHOB expression. We propose that miR-21 has good potential as a clinically useful diagnostic and prognostic biomarker of hypoxia and prostate cancer.

640 - MicroRNA-21 overexpression attenuates excess androgen-mediated brown adipose tissue lipid droplet hypertrophy in polycystic ovarian syndrome

640 - MicroRNA-21 overexpression attenuates excess androgen-mediated brown adipose tissue lipid droplet hypertrophy in polycystic ovarian syndrome

A NIR light gated targeting nanoprobe based on DNA-modified upconversion nanoparticles with antifouling properties for ratiometric detection and imaging of microRNA-21

The overexpression of microRNA-21 is closely related to many human diseases, so the development of probes for this bio-marker will contribute to the diagnosis. In this scheme, a novel ratiometric upconversion nanoprobe based on fluorescence resonance energy transfer (FRET) was developed for the analysis of microRNA-21. This nanosystem is composed of upconversion nanoparticles (UCNPs), PEG with antifouling performance and targeted folic acid (FA). Er3+ doped UCNPs were used as energy donors and carboxy-X-rhodamine (ROX) acted as energy receptors. MicroRNA-21 was visually analyzed by ratiometric upconversion luminescence (548 nm/616 nm), and the limit of detection (LOD) was quantified to be 9.95 pM. This nanocomposite can not only realize the detection and imaging for microRNA-21 in cells, but also visualize microRNA-21 level in vivo by upconversion luminescence due to the deep tissue penetration of UCNPs.

Radiation-resistance increased by overexpression of microRNA-21 and inhibition of its target PTEN in esophageal squamous cell carcinoma.

ObjectiveOverexpression of microRNA-21 (miR-21) increases the radiation resistance of esophageal squamous cell carcinoma (ESCC). However, the molecular mechanism responsible for this action is still unclear. In the present study, we investigated the role of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in miR-21-enhanced radiation resistance in patients with ESCC.MethodsWe evaluated the association between miR-21 levels and radiation resistance in patients with ESCC. We also investigated the role of PTEN in the proliferation and apoptosis of ESCC cells transfected with miR-21 inhibitor during irradiation, using PTEN small interfering RNA (siRNA).ResultsMiR-21 levels were significantly higher in radiation-resistant patients. Downregulation of miR-21 during irradiation suppressed the radiation resistance of ESCC cells, demonstrated by decreased cell proliferation and increased cell apoptosis. PTEN siRNA attenuated miR-21-induced suppression of radiation resistance in ESCC cells.ConclusionsThese results suggest that miR-21 enhanced the radiation resistance of ESCC by inhibiting PTEN. MiR-21 and PTEN are potential therapeutic biotargets for ESCC.

Overexpression of microRNA-21 decreased the sensitivity of advanced cervical cancer to chemoradiotherapy through SMAD7.

Drug resistance is a major problem in the treatment of advanced cervical cancer. The oncogenic microRNA-21 (miR-21) is involved in drug resistance in various cancers. However, the regulatory role of miR-21 and its target, Smad7 in drug resistance of cervical cancer remains to be elucidated. We compared miR-21 and Smad7 levels in human samples from chemoradiotherapy-resistance cervical cancer (resistant group) and chemoradiotherapy-sensitive cervical cancer (sensitive group) patients. Then, the miR-21 level was manipulated in HeLa and SiHa cervical cancer cells and the Smad7 level was determined by PCR and western blot. We also manipulated miR-21, Smad7 or both in cells, and measured cell viability using cell counting kit-8 method and epithelial-mesenchymal transition (EMT) biomarkers using Western blot. In human samples, resistant group has significantly higher miR-21 and lower Smad7 levels than sensitive group. In-vitro analysis demonstrated downregulated Smad7 after transfection with miR-21 mimics. When cells were transfected with Smad7 inhibitor, we observed increased drug resistance and changed levels of EMT-biomarkers after chemoradiotherapy, suggesting that downregulation of Smad7 decreased the sensitivity through EMT. When the cells were transfected with miR-21 inhibitor alone, we found increased sensitivity to chemoradiotherapy through EMT. However, such effects were attenuated when Smad7 was also downregulated after cotransfection. In summary, we provided clinical and experimental evidence that decreased miR-21 may improve drug resistance through EMT by direct targeting Smad7 in cervical cancer. Our data suggest that miR-21/Smad7 pathway may be an effective target for drug resistance in cervical cancer treatment.

Curcumin alleviates TGF-β1-induced fibrosis in NRK-49F cells via suppression of miR-21 expression, and regulation of the TGF-β1/smad3 signaling pathway

Abstract Objective Overexpression of microRNA-21 (miR-21) has been well-recognized during fibrosis in a wide range of tissue types through regulation of fibrogenesis via diverse pathways. Curcumin exhibits anti-fibrotic effects in various organs. We and others have previously demonstrated that curcumin has positive effects on the protection against fibrosis. However, the effect of curcumin on miR-21 expression has not been reported. Methods In this study, transforming growth factor-β1 (TGF-β1)-stimulated rat renal fibroblast cells (NRK-49F) were transfected with miR-21 inhibitors, then the expression of Smad3, α-smooth muscle actin (α-SMA), type I collagen (COL1A1), and type Ⅲ collagen (COL3A1) was determined using quantitative real-time-PCR (qRT-PCR) and western blot analysis. The effect of curcumin on production of the extracellular matrix was evaluated using immunofluorescence, qRT-PCR, and western blot analysis. Results TGF-β1 stimulation upregulated the expression of miR-21 and induced fibrogenesis in NRK-49F cells. Transfection with miR-21 inhibitors selectively decreased smad3 activity, and noticeably reduced the expression of α-SMA, COL1A1, and COL3A1. Curcumin treatment significantly inhibited the expressions of smad3, α-SMA, COL1A1, COL3A1, as well as miR-21 expression in NRK-49F cells in a dose-dependent manner. Conclusion Curcumin exerted its anti-fibrotic effects by targeting the TGF-β1/smad3 signaling pathway and suppressing miR-21 expression, thereby provides novel insight in the protective effects of curcumin against fibrosis in various organs.

Overexpression of microRNA-21 mediates Ang II-induced renal fibrosis by activating the TGF-β1/Smad3 pathway via suppressing PPARα

Angiotensin II (Ang II) is an important profibrotic factor, and the tumor-promoting microRNA miR-21 was recently linked to fibrotic disorders. We aimed to investigate whether and how miR-21 mediates Ang II-induced renal fibrosis. In renal tubular epithelial cells, Ang II upregulated miR-21 and fibrosis-related indicators but decreased PPARα expression. miR-21 overexpression promoted PPARα downregulation, activated the TGF-β1/Smad3 pathway and induced fibrogenesis, while miR-21 suppression exerted opposite effects. In Ang II-treated cells, reduced PPARα expression, TGF-β1/Smad3 pathway activation and fibrogenesis were all exacerbated by miR-21 upregulation but alleviated by miR-21 inhibition. The dual-luciferase assay confirmed PPARα as the target of miR-21. PPARα silencing alone could overactivate the TGF-β1/Smad3 pathway in the presence or absence of Ang II. Importantly, the regulatory effects of miR-21 knockdown and the angiotensin type 1 receptor blocker losartan alone or in combination on the PPARα/TGF-β1/Smad3 pathway in Ang II-treated cells were almost the same. More crucially, PPARα restoration abolished the profibrotic effect of miR-21 overexpression. In addition, inhibiting miR-21 in Ang II-treated mice effectively ameliorated the abnormally activated PPARα/TGF-β1/Smad3 pathway, albuminuria, and renal fibrosis without lowering blood pressure. These results demonstrated that miR-21 extensively mediates Ang II-induced kidney fibrosis via amplifying the TGF-β1/Smad3 pathway by targeting PPARα.

Celastrol inhibits growth and metastasis of human gastric cancer cell MKN45 by down-regulating microRNA-21.

Celastrol could inhibit cancer cell growth in vitro. However, effect(s) of celastrol on gastric cancer is not well studied. Therefore, we investigated the effects of celastrol on human gastric cancer cell line MKN45 and the underlying mechanisms. We found that celastrol inhibited cell proliferation, migration, and invasion and induced cell apoptosis and G2/M cell cycle arrest (p<.05, p<.01, or p<.001). Under celastrol treatment, overexpression of microRNA-21 (miR-21) increased cell viability, migration, and invasion and inhibited cell apoptosis compared with negative control (p<.05, p<.01, or p<.001). In addition, the phosphorylation of PTEN was significantly up-regulated, whereas PI3K, AKT, p65, and IκBα phosphorylation was statistically decreased by celastrol (p<.05 or p<.01) and then further reversed by miR-21 overexpression (p<.05 or p<.01). On the other side, miR-21 silence showed contrary results (p<.05) as relative to miR-21 overexpression. In conclusion, celastrol inhibits proliferation, migration, and invasion and inactivates PTEN/PI3K/AKT and nuclear factor κB signaling pathways in MKN45 cells by down-regulating miR-21.

MicroRNA-21 Overexpression Promotes the Neuroprotective Efficacy of Mesenchymal Stem Cells for Treatment of Intracerebral Hemorrhage.

Intracerebral hemorrhage (ICH) has high morbidity and mortality, with no effective treatment at present. One possible therapeutic strategy involves the use of mesenchymal stem cells (MSCs), which have shown promise in experimental models and have great potential for treating nervous illnesses in humans. However, many deficiencies in MSC treatment still need to be addressed, including their poor survival rate post-transplantation. Previously, we reported that the microRNA-21 (miR-21) is downregulated in ICH patients' blood and brain tissue. In this study, we aimed to examine its role and therapeutic efficacy in ICH using miR-21-overexpressing MSCs. We found that this microRNA can enhance MSC survival and recovery of neurological function in ICH rats. Its mechanism of action involves reduced neuronal apoptosis. In addition, we demonstrated that miR-21 can be transported to neurons through exosomes derived from MSCs and that it can target transient receptor potential melastatin 7 (TRPM7) to alleviate neuronal injury following ICH. We also observed that the NF-κB pathway is involved in the regulation of miR-21 in neural cells. In conclusion, miR-21 significantly enhances the survival of MSCs in ICH, and miR-21-overexpressing MSCs clearly improved neurological function in ICH rats. Transplantation of miR-21-overexpressing MSCs may, therefore, provide an effective strategy for neuroprotection and treatment of cerebrovascular diseases.

Low expression of microRNA-21 inhibits trophoblast cell infiltration through targeting PTEN.

We investigate whether microRNA-21 could increase the infiltration ability of trophoblast cells via regulating PTEN expression, thus participating in the occurrence and development of preeclampsia. MicroRNA-21 expression in the placenta tissues of preeclampsia women and normal pregnant women was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The effects of microRNA-21 on cell proliferation and infiltration were examined by cell counting kit-8 (CCK-8) and transwell assay, respectively. The dual-luciferase reporter gene assay was used to determine the binding relationship between microRNA-21 and PTEN. Western blot was performed to detect PTEN and microRNA-21 in trophoblasts. QRT-PCR results showed that the microRNA-21 expression was significantly lower in the placenta of the preeclampsia women than those of normal pregnant women. Overexpression of microRNA-21 in HTR-8/SVneo cells had no effect on cell proliferation, but enhanced cell infiltration ability. Inhibition of microRNA-21 in trophoblasts showed the opposite effects. The results of luciferase activity assay and Western blot showed that microRNA-21 could target PTEN and downregulate its expression. Overexpression of PTEN in HTR-8/SVneo cells partially reversed the enhanced invasive ability induced by microRNA-21 overexpression. Low expression of microRNA-21 attenuated cell infiltration of trophoblasts via direct regulating PTEN expression.

Role of microRNA-21 in uveal melanoma cell invasion and metastasis by regulating p53 and its downstream protein.

To reveal the insight mechanism of liver metastasis in uveal melanoma, we investigated cell functions of microRNA-21 in three different uveal melanoma cell lines and analyze the relationship of target gene p53 and its downstream targets. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect microRNA-21 expression in normal uveal tissue and uveal melanoma cell lines. Lenti-virus expression system was used to construct OCM-1, MuM-2B and M619 cell line with stable overexpression and inhibition of microRNA-21. In vitro cell function tests such as cell proliferation, cell apoptosis, cell circle and abilities of migration and invasion were examined by MTT, BrdU assay, flow cytometry, transwell assay and Matrigel invasion assay respectively. The target gene was predicted by bioinformatics and confirmed by using a dual luciferase reporter assay. The expression of p53 and its suspected downstream targets LIM and SH3 protein 1 (LASP1) and glutathione S transferase pi (GST-Pi) were determined by qRT-PCR in mRNA level and Western blotting analysis in protein level. Finally, the effect of microRNA-21 in a xenograft tumor model was assessed in four-week-old BALB/c nude mice. Compared to normal uveal melanoma, expressions of microRNA-21 were significantly higher in uveal melanoma cell lines. Overexpression of microRNA-21 promoted proliferation, migration, and invasion of OCM-1, M619 and MuM-2B cells, while inhibition of microRNA-21 reveal opposite effects. Wild type p53 was identified as a target gene of microRNA-21-3p, and proved by dual luciferase reporter assay. Up-regulated microRNA-21 inhibited the expression of wild type p53 gene, and the increased expression of LASP1 in mRNA level and protein level, while down-regulated microRNA-21 presented opposite way. However, GST-pi showed the potential pattern as expected, but relative mRNA level showed no statistically significant difference in OCM-1 cells. Furthermore, the mRNA expression of GST-pi was decreased in microRNA-21 overexpressing MuM-2B, and increased in M619 cells with inhibition of microRNA-21. In vivo, inhibition of microRNA-21 reduced tumor growth with statistically significant difference. These findings provide novel insight into molecular etiology of microRNA-21 in uveal melanoma cell lines, and suggest that microRNA-21 might be a potential candidate for the diagnosis and prognostic factor of human uveal melanoma.

Isoalantolactone Inhibits Esophageal Squamous Cell Carcinoma Growth Through Downregulation of MicroRNA-21 and Derepression of PDCD4.

This study was designed to explore the anticancer potential of isoalantolactone, a sesquiterpene lactone, on esophageal squamous cell carcinoma (ESCC) cells and associated molecular mechanisms. ESCC cell lines were treated with isoalantolactone or vehicle and tested for viability, proliferation, cell cycle distribution, and apoptosis. Xenograft tumor studies in nude mice were done to examine the in vivo anticancer effect of isoalantolactone. Isoalantolactone treatment reduced ESCC cell viability and proliferation in vitro, which was coupled with induction of G0/G1 cell cycle arrest and apoptosis. In vivo studies confirmed the growth-suppressive effect of isoalantolactone on ESCC cells. Mechanistically, isoalantolactone reversed microRNA-21-mediated repression of programmed cell death 4 (PDCD4). Overexpression of microRNA-21 and knockdown of PDCD4 blocked the growth suppression and apoptosis induction by isoalantolactone in ESCC cells. Isoalantolactone shows growth-suppressive activity against ESCC cells, which is ascribed to upregulation of PDCD4 via downregulation of microRNA-21.

A Novel Oncolytic Herpes Simplex Virus Design based on the Common Overexpression of microRNA-21 in Tumors.

Recognition sequences for microRNAs (miRs) that are down-regulated in tumor cells have recently been used to render lytic viruses tumor-specific. Since different tumor types down-regulate different miRs, this strategy requires virus customization to the target tumor. We have explored a feature that is shared by many tumor types, the up-regulation of miR-21, as a means to generate an oncolytic herpes simplex virus (HSV) that is applicable to a broad range of cancers. We assembled an expression construct for a dominant-negative (dn) form of the essential HSV replication factor UL9 and inserted tandem copies of the miR-21 recognition sequence (T21) in the 3' untranslated region. Bacterial Artificial Chromosome (BAC) recombineering was used to introduce the dnUL9 construct with or without T21 into the HSV genome. Virus was produced by transfection and replication was assessed in different tumor and control cell lines. Virus production was conditional on the presence of the T21 sequence. The dnUL9-T21 virus replicated efficiently in tumor cell lines, less efficiently in cells that contained reduced miR-21 activity, and not at all in the absence of miR-21. miR-21-sensitive expression of a dominant-negative inhibitor of HSV replication allows preferential destruction of tumor cells in vitro. This observation provides a basis for further development of a widely applicable oncolytic HSV.

TIMP-3 mRNA expression levels positively correlates with levels of miR-21 in in situ BC and negatively in PR positive invasive BC

BackgroundBreast carcinomas (BC) belong to a heterogeneous group of malignant diseases. Correct categorization of BC based on molecular biomarkers has a very important role in deciding the proper course of therapy for each patient. It has been already shown that the decrease of TIMP metalloproteinase inhibitor 3 (TIMP-3) together with overexpression of microRNA-21 (miR-21) might be involved in the process of BC invasion. This is the first study that examined relationship among miR-21, TIMP-3 mRNA and TIPM-3 protein levels in BC groups formed according to invasiveness. MethodsIn this study, we used 46 breast cancer samples. Estrogen and progesterone receptor (ER, PR) protein levels were evaluated by immunohistochemistry (IHC) method. TIMP-3 mRNA expression was examined by two-step real-time quantitative PCR (qRT-PCR). Western blot analysis was performed for 16 samples. ResultsStatistically significant differences in TIMP-3 expression levels between invasive groups were discovered in ER positive (ER+) (p=0.015), Her-2 negative (p=0.026) subgroups, and patients without lymph-node metastasis (p=0.039). Interestingly, significant positive correlation was detected between miR-21 and TIMP-3 mRNA levels (P<0.001, ρ=0.949) in the group of in situ tumors. TIMP-3 mRNA expression levels highly negatively correlated with levels of miR-21 in PR+ invasive BCs (p=0.007, ρ=−0.641). TIMP-3 protein levels negatively correlated with miR-21 levels in pure invasive BCs. ConclusionThese data suggest that signaling pathways involved in formation and progression of BCs in groups formed according to invasiveness might be different. Our findings propose that TIMP-3 mRNA expression levels could be significant prognostic parameter, but within specific BC subtypes.

MicroRNA-21 could be a molecular marker to predict the recurrence of nonmuscle invasive bladder cancer

Introduction:High relapse rate of nonmuscle invasive bladder cancer (NMIBC) is a major challenge. Overexpression of microRNA-21 (miR-21) which targets phosphatase and tensin homolog (PTEN), a gene associated with malignancy, has been reported in the bladder tumor tissue compared to normal mucosa by us and others. We have tested whether miR-21 levels in bladder mucosa could predict tumor recurrence.Methods:In a prospective cohort setting, tumor tissues and normal bladder mucosa (NBM) were taken from BC patients during transurethral resection of bladder tumor. Age- and ethnicity-matched NBM from benign prostate hyperplasia patients was taken as controls. The expression of miR-21 was analyzed using quantitative reverse transcription polymerase chain reaction. Patients were followed for 4 years for tumor reoccurrence. Postoperative recurrence were recorded and calculated by Kaplan–Meier curve.Results:In 31 patients, miR-21 was up-regulated (>4-fold, P = 0.003), and PTEN levels were significantly lower (<7-folds, P = 0.001) in tumor tissue relative to NBM. Moreover, the fold change in miR-21 levels was significantly higher (>3-folds, P = 0.03) in patients showing recurrence compared to those in which tumor did not recur. Further, Kaplan–Meier analysis shows overexpression of miR-21 corresponds to less time to recurrence with higher cumulative hazard.Conclusion:We found overexpression of miR-21 in tumor tissue and its association with recurrence, time to recurrence and invasiveness in BC. Quantification of miR-21 along with other pathological parameters could be more objective molecular approach to predict recurrence in NMIBC.

Molecular Simulation Studies of 3,3'-Diindolylmethane as a Potent MicroRNA-21 Antagonist.

Objective:In recent decades, the overexpression of microRNA-21 (miR-21) is found to be progressively linked with many diseases such as different types of cancers, cardiovascular diseases, and inflammation. Thereby, it has become an attractive target for pharmacological and genetic modulation in various diseases, and also for overcoming the resistance to chemotherapy in several cancers. Here, in this study, the role of molecular therapeutics of 3,3′-diindolylmethane (DIM) has been investigated for its ability to bind with the precursor miRNA as a target of miR-21 (hsa-mir-21), which may alter the catalyzation process of dicer, a RNase III enzyme, involved in miRNA transcription.Methods:In this context, the present study describes the potential binding and the structure alteration properties of DIM to precursor miR-21 (pre-miR-21) through Molecular Docking and Molecular Dynamics simulation techniques.Results:As a corollary, DIM formed both non-bonded and covalent interactions with the bases of pre-miR, while covalent interaction with guanine in the 6th position was found to be consensus in molecular dynamics simulation. Furthermore, the stability of both DIM and pre-miR-21 was found to be inversely correlated to each other in binding condition.Conclusion:This result indicates that DIM can be used in target-based therapy and also as a lead for further development of potent small molecule miRNA antagonist.

Overexpression of microRNA-21 strengthens stem cell-like characteristics in a hepatocellular carcinoma cell line.

BackgroundLiver cancer stem cells (LCSCs) have been shown to express higher levels of microRNA-21 (miR-21). Here, we examine the possible contributions of miR-21 to the phenotype of LCSCs in culture and in xenograft tumors in nude mice.MethodsThe hepatocellular carcinoma cell line MHCC-97H was stably transformed with a retroviral vector to establish cells overexpressing miR-21, while a cell line transformed with empty vector served as a negative control. RT-PCR and Western blotting were used to evaluate the effects of miR-21 overexpression on the expression of various LCSC markers, a Transwell assay was used to assess the effects on cell migration and invasion, and a spheroid formation assay was used to examine the effects on clonogenesis. The effects of miR-21 overexpression were also examined in tumors in nude mice.ResultsAn MHCC-97H cell line was constructed that stably overexpresses miR-21 at 7.78 ± 1.51-fold higher levels than the negative control cell line. Expression of the LCSC markers CD13, Ep-CAM, CD90, and OCT4 was significantly higher in the miR-21-overexpressing cell line than in the negative control at both mRNA and protein levels. The overexpressing cell line formed larger, tighter, and more numerous spheroids. Overexpression of miR-21 was associated with greater cell migration and invasion. Tumors of overexpressing cells in nude mice had a significantly larger mean volume after 34 days of growth (773.62 ± 163.46 mm3) than tumors of negative control cells (502.79 ± 33.94 mm3, p = 0.048), as well as greater mean weight (0.422 ± 0.019 vs. 0.346 ± 0.006 g, p = 0.003).ConclusionsOverexpression of miR-21 strengthens the phenotype of LCSCs, facilitating invasion, migration, and tumorigenesis in hepatocellular carcinoma.

MicroRNA-100 and microRNA-21 as markers of survival and chemotherapy response in pancreatic ductal adenocarcinoma UICC stage II.

BackgroundPancreatic ductal adenocarcinoma (PDAC) remains a highly chemoresistant tumor entity for which no reliable molecular targets exist to predict or influence the success of chemotherapy. Recently, we identified a panel of microRNAs associated with induced gemcitabine chemoresistance in human PDAC cell lines. This clinical study evaluates these microRNAs and associated molecular markers as prognostic markers of outcome in 98 PDAC patients Union Internationale Contre le Cancer (UICC) stage II undergoing curative surgery with adjuvant gemcitabine chemotherapy. The primary end points of this study are recurrence-free survival and overall survival.ResultsPoor response to chemotherapy was significantly correlated to overexpression of microRNA-21 (p = 0.029), microRNA-99a (p = 0.037), microRNA-100 (p = 0.028), and microRNA-210 (p = 0.021) in tissue samples of PDAC patients UICC stage II. Upregulation of these microRNAs was associated with a significantly shorter overall survival and recurrence-free survival (p < 0.05). Overexpression of phosphatase and tensin homolog (PTEN) (p = 0.039) and low expression of multidrug resistance (MDR)-1 (p = 0.043) and breast cancer resistance protein (BCRP)-1 (p = 0.038) were significantly correlated to improved response to adjuvant chemotherapy. Adjuvant gemcitabine treatment (p < 0.0001) and low tumor grading (p = 0.047) were correlated to better outcome. MicroRNA-100, microRNA-21, and its targets PTEN and MDR-1 were independent factors of survival in multivariate analysis.ConclusionsMultivariate survival analyses identified microRNA-21 and microRNA-100 as unfavorable prognostic factors in resected and adjuvant treated PDAC UICC stage II patients.

Anti-inflammatory effects of miR-21 in the macrophage response to peritonitis

We investigated the role of microRNA-21 in the macrophage response to peritonitis; microRNA-21 expression increases in peritoneal macrophages after lipopolysaccharide stimulation but is delayed until 48 hours after cecal ligation and puncture. MicroRNA-21-null mice and bone marrow-derived cell lines were exposed to cecal ligation and puncture or lipopolysaccharide, and survival, microRNA-21 levels, target messenger RNAs and proteins, and cytokines were assayed. Macrophages were also transfected with microRNA-21 mimics and antagomirs, and similar endpoints were measured. Survival in microRNA-21-null mice was significantly decreased after lipopolysaccharide-induced peritonitis but unchanged after cecal ligation and puncture compared with similarly treated wild-type mice. MicroRNA-21 expression, tumor necrosis factor-α, interleukin 6, and programmed cell death protein 4 levels were increased after lipopolysaccharide addition in peritoneal cells. Pelino1 and sprouty (SPRY) messenger RNAs were similarly increased early, whereas programmed cell death protein 4 messenger RNA was decreased after lipopolysaccharide, and all microR-21 target messenger RNAs were subsequently decreased by 24 hours after lipopolysaccharide. Transfection with mimics and antagomirs led to appropriate responses in microRNA-21 and tumor necrosis factor-α. Knockdown of microRNA-21 in bone marrow-derived cells showed increased tumor necrosis factor-α and decreased interleukin 10 in response to lipopolysaccharide. Target proteins were unaffected by knockdown as was extracellular signal-regulated kinase; however, the nuclear factor κB p65 subunit was increased after lipopolysaccharide in the microRNA-21 knockout cells. In contrast, there was little change in these parameters after cecal ligation and puncture induction between null and wild-type mice. MicroRNA-21 is beneficial to survival in mice following lipopolysaccharide peritonitis. Overexpression of microRNA-21 decreased tumor necrosis factor-α secretion, whereas suppression of microRNA-21 expression increased tumor necrosis factor-α and interleukin 6, and decreased interleukin 10 levels after lipopolysaccharide. Protein targets of microRNA-21 were not different following suppression of microRNA-21. Nuclear factor κB was increased by suppression of microRNA-21. These findings demonstrate microRNA-21 is beneficial in modulating the macrophage response to lipopolysaccharide peritonitis and an improved understanding of the anti-inflammatory effects of microRNA-21 may result in novel, targeted therapy against peritonitis and sepsis.

MicroRNA-21 is a potential link between non-alcoholic fatty liver disease and hepatocellular carcinoma via modulation of the HBP1-p53-Srebp1c pathway

BackgroundNon-alcoholic fatty liver disease (NAFLD) is a major risk factor for hepatocellular carcinoma (HCC). However, the mechanistic pathways that link both disorders are essentially unknown.ObjectiveOur study was designed to investigate...