Investigation of the Effects of MicroRNA-221 Expression Levels in Glioblastoma Multiforme Tumors

BACKGROUND/AIM

The aim of our study was to examine miRNA-221 as a candidate biomarker to define prognosis and/or classification for glial tumors.

MATERIALS AND METHODS

This study included 39 patients who underwent glial tumor surgery and 40 healthy individuals as the control group. miRNA expression levels were determined by real-time polymerase chain reaction (RT-PCR). Receiver operating characteristic curve analysis was used for analyzing the predictive ability of miRNA-221.

RESULTS

The levels of miRNA-221 expression were determined by comparing the ΔCT values of miRNAs and the internal control. When the expression levels of miRNA-221 were compared according to the ΔCT method, miRNA-221 was found to be significantly increased in the patient group compared to the control group (p<0.0001).

CONCLUSION

Increased expression levels of miRNA-221 could be a biomarker for glial tumors.

New advances on the inhibition of Siwei Xiaoliuyin combined with Temozolomide in glioma based on the regulatory mechanism of miRNA21/221

OBJECTIVE

To provide evidence for the mechanism of Chinese medicine to treat glioma. We observe the effects of Si wei xiao xiu yin combined with chemotherapy on the growth of subcutaneous xenografts in nude mice and the expression of miRNA-21 and miRNA-221 in tumor tissues.

METHODS

The subcutaneous transplantation model of nude mice was established by subcutaneous inoculation of glioma U87 cell suspension. They were randomly divided into saline group, traditional Chinese medicine group, temozolomide group and traditional Chinese medicine combined with temozolomide group to observe the changes in body weight, and the tumor weight, length, short diameter, volume of mice. The relative expression levels of miRNA-21 and miRNA-221 in tumor tissues were detected by qRT-PCR, and the differences between groups were compared.

RESULTS

After 28 days of gavage, the tumor growth of the other three groups was slower than that of saline group, and the difference was most significant in the combination group (P=0.008<0.05), besides, the relative expression of the three groups of miRNA-21 and miRNA-221 was significantly inhibited compared with saline group, and the difference was significant in the combination group (F=8.918, P=0.010<0.05).

CONCLUSION

To some extent, Si wei xiao xiu yin combined with temozolomide can inhibit the growth of subcutaneous xenografts in glioma nude mice. The mechanism may be related to the inhibition of miRNA-21 and miRNA-221 expression.

miRNA-Specific Unlocking of Drug-Loaded Metal-Organic Framework Nanoparticles: Targeted Cytotoxicity toward Cancer Cells

UiO-68 metal-organic framework nanoparticles (NMOFs) are loaded with a doxorubicin drug (fluorescent dye analogs) and locked by means of structurally engineered duplex nucleic acid structures, where one strand is covalently linked to the NMOFs and the second strand is hybridized with the anchor strand. Besides the complementarity of the second strand to the anchor sequence, it includes the complementary sequence to the microRNAs (miRNA)-21 or miRNA-221 that is specific miRNA biomarker for MCF-7 breast cancer cells or OVCAR-3 ovarian cancer cells. In the presence of the respective miRNA biomarkers, the miRNA-induced displacement of the strand associated with the anchor strand proceeds, resulting in the release of DNA/miRNA duplexes. The released duplexes are, however, engineered to be digested in the presence of exonuclease III, Exo III, a process that recycles the miRNAs and provides the autonomous amplified unlocking of the NMOFs and the release of the doxorubicin load (or the fluorescent dye analogs) even at low concentrations of miRNA. Preliminary cell experiments reveal that the respective NMOFs are unlocked by the miRNA-21 or miRNA-221, resulting in selective cytotoxicity toward MCF-7 breast cancer cells or OVCAR-3 ovarian cancer cells.

The Biology of β-D-mannuronic acid (M2000) on Human Dendritic Cell Based on MicroRNA-155 and MicroRNA-221

BACKGROUND

The aim of this study was to evaluate the effect of ß-Dmannuronic acid (M2000) on related miRNAs to dendritic cells (DCs) differentiation. DC-based immunosuppressive drugs can suppress the progression of autoimmune diseases, however, their notable side effects in increasing the risk of infectious diseases and cancers should be considered. The β-D-mannuronic acid, as a novel non-steroidal anti-inflammatory agent, has been tested in various experimental models.

METHOD

The effect of M2000 on expression of miRNA-155 and miRNA-221 was examined. To investigate how M2000 affects differentiation of human dendritic DCs in a defined inflammatory environment, human peripheral blood mononuclear cells were isolated from healthy blood and the monocytes were purified using anti-CD14 microbeads. The so isolated monocytes were subsequently incubated in the presence of M2000 in two different doses (3 and 6 mMol/well) adding granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 for inducing monocytes to immature DC and lipopolysaccharide for running DC differentiation. The expression of miRNA-155 and miRNA-221 were examined with Real Time PCR.

RESULTS

The results demonstrate that M2000 has no significant side effect on expression of miR-155 and miR-221 in both immature DC and mature DC process in vitro.

CONCLUSION

Our findings show that β-D-mannuronic acid is a safe agent which has no adverse effect on regulatory miRNA-155 and miRNA-221 in dendritic cells.

miRNA-221 promotes cutaneous squamous cell carcinoma progression by targeting PTEN

Background

Cutaneous squamous cell carcinoma (CSCC) is a common type of skin malignancy. MicroRNA-221 (miRNA-221) is a critical non-coding RNA in tumor initiation and progression. However, the molecular mechanisms of miRNA-221 in the development of CSCC remain unknown. This study investigated the expression of miRNA-221 in CSCC and its potential tumor biological functions.

Methods

MTT assay, colony assay, PCR, and Western blot were adopted.

Results

In this study, miRNA-221 expression was significantly higher in CSCC tissues and cell lines than in normal tissues and cells (P < 0.05). Further functional experiments indicated that miRNA-221 knockdown inhibited the proliferation and cell cycle, while upregulation of miRNA-221 presented the opposite role. The dual reporter gene assays indicated that PTEN is a direct target gene of miRNA-221. PTEN protein or mRNA levels were decreased after the cells were transfected with miR-221 mimics.

Conclusions

Taken together, the obtained results indicated that miR-221 plays an oncogenic function in CSCC by targeting PTEN and further suggest that miR-221 may be a potential target for CSCC diagnosis and treatment.

Protective role of microRNA-221 in Parkinson's disease

OBJECTIVE

The present study aimed to explore the role and the underlying mechanism of miR-221 in Parkinson's Disease.

MATERIALS AND METHODS

To perform our investigation, a PD cell model was created by using 6-OHDA. Cell viability and proliferation assays, and flow cytometry analysis were performed to detect cell viability and apoptosis. The qRT-PCR and western blotting were used for gene and protein level detection.

RESULTS

We found that the expression of miRNA-221 is significantly lower in 6-OHDA treated PC12 pheochromocytoma cells compared to the normal cells. The results of further analysis indicated that miR-221 mimic significantly promoted the cell viability and proliferation of PC12 cells treated with 6-OHDA. MiR-221 mimic significantly inhibited 6-OHDA-treated PC12 cells from apoptosis. These effects were eliminated by PTEN over-expression. We also revealed that PTEN was a direct target gene of miR-221. Moreover, we found miR-221 mimic significantly promoted the phosphorylation of AKT in PC12 cells treated with 6-OHDA, and over-expression of PTEN could eliminate this effect.

CONCLUSIONS

MiR-221 plays a protective role in Parkinson's Disease via regulating PC12 cell viability and apoptosis by targeting PTEN. Therefore, miR-221 may serve as a potential therapeutic target for Parkinson's disease treatment (Fig. 3, Ref. 27).

Expression of miRNA-21 and miRNA-221 in clear cell renal cell carcinoma (ccRCC) and their possible role in the development of ccRCC

AIM

Clear cell renal cell carcinoma (ccRCC) is the third most common urological cancer after prostate and bladder cancer but has the highest rate of mortality affecting over 40% of patients. microRNAs (miRNAs) are small noncoding RNAs that have become potential biomarkers and molecular targets for cancer treatment. Molecular markers such as miRNAs may have a role in the diagnosis of ccRCC. In this study, we examined the expressions of miRNA-21 and miRNA-221 in renal cancer patients׳ tumor and adjacent paired normal tissues investigating the possible role of these miRNAs in the development of ccRCC.

MATERIALS AND METHODS

Renal tumors (n = 24) and paired normal renal tissue (n = 24) samples, obtained from the Department of Urology, University of Debrecen, were analyzed for miRNA-21 and miRNA-221 expressions with quantitative real-time polymerase chain reaction.

RESULTS

miRNA-21 and miRNA-221 expressions were significantly up-regulated in tumor specimens compared to normal tissue (P<0.05). miRNA-21 and miRNA-221 showed coexpression pattern in 19 (79.2%) cases of tumor samples and 8 (33.3%) cases of paired normal renal tissues. Increased miRNA pattern showed a positive correlation with pathological status of the patients.

CONCLUSIONS

Expression of oncogenic miRNA-21 and miRNA-221 in human ccRCC tumor tissue samples compared to adjacent nontumorous tissues might suggest that these miRNAs are involved in the development of ccRCC.

Expression of miR-221 in colon cancer correlates with prognosis

MicroRNAs are increasingly important in the study of cancer because of their ability to down regulate the expression of tumor suppressors and promote tumorigenesis. Here, miR-221, which is dysregulated in various tumors, was investigated for its expression in colon cancer tissues and its correlation with patient prognosis. Colon cancer tissue samples were obtained from 182 individuals who underwent surgical resection in our hospital from June 2008 to September 2009. Real-time PCR was used to detect the expression of miR-221 in these tissues. Patient survival was determined by telephone interview, and survival curves were plotted by using the Kaplan-Meier method and compared by the Log-rank test. Statistical methods also included X(2) test and Cox proportional hazard regression model. Differences in the expression of miR-221 by gender, pathology, and pathological staging were not statistically significant (P>0.05), but differences in the expression of miR-221 among age groups were statistically significant (P<0.05). A survival analysis indicated that high expression of miR-221 was closely associated with a shorter survival time (P<0.05). Further, later p-TNM (hazard ratio, HR=2.973, 95% confidence interval, CI: 1.329-6.519, P=0.003) and high expression of miR-211 (HR=2.394, 95% CI: 1.210-4.910, P=0.006) were identified as risk factors for colon cancer prognosis. Thus, high miRNA-221 expression might be a prognostic marker of colon cancer patients. The high expression of miRNA-221 was associated with poor prognosis of patients with colon cancer.

miRNA-221 is elevated in cystic fibrosis airway epithelial cells and regulates expression of ATF6

Background

MicroRNA (miRNA) and messenger RNA (mRNA) expression differs in cystic fibrosis (CF) versus non-CF bronchial epithelium. Here, the role of miRNA in basal regulation of the transcription factor ATF6 was investigated in bronchial epithelial cells in vitro and in vivo.

Methods

Using in silico analysis, miRNAs predicted to target the 3′untranslated region (3′UTR) of the human ATF6 mRNA were identified.

Results

Three of these miRNAs, miR-145, miR-221 and miR-494, were upregulated in F508del-CFTR homozygous CFBE41o- versus non-CF 16HBE14o- bronchial epithelial cells and also in F508del-CFTR homozygous or heterozygous CF (n = 8) versus non-CF (n = 9) bronchial brushings. ATF6 was experimentally validated as a molecular target of these miRNAs through the use of a luciferase reporter vector containing the full-length 3′UTR of ATF6. Expression of ATF6 was observed to be decreased in CF both in vivo and in vitro. miR-221 was also predicted to regulate murine ATF6, and its expression was significantly increased in native airway tissues of 6-week-old βENaC-overexpressing transgenic mice with CF-like lung disease versus wild-type littermates.

Conclusions

These results implicate miR-145, miR-221 and miR-494 in the regulation of ATF6 in CF bronchial epithelium, with miR-221 demonstrating structural and functional conservation between humans and mice. The altered miRNA expression evident in CF bronchial epithelial cells can affect expression of transcriptional regulators such as ATF6.

Circulating microRNA-122a as a diagnostic marker for hepatocellular carcinoma

BACKGROUND

The purpose of this study was to evaluate the potential value of circulating miRNA-122a and miRNA-221 in the diagnosis of hepatocellular carcinoma.

METHODS

Serum samples were obtained from 85 patients with hepatocellular carcinoma and 85 age-matched and sex-matched healthy volunteers. miRNAs were isolated from the serum samples, and alfa-fetoprotein levels were determined. Expression of miRNA-122a and miRNA-221 in cases and controls was quantified using U6 sn RNA as the internal control. The diagnostic value of miRNA-122a, miRNA-221, and alfa-fetoprotein was compared by receiver operating characteristic analysis.

RESULTS

The serum miRNA-122a level in patients with hepatocellular carcinoma was significantly reduced in comparison with healthy controls and correlated with known risk factors for hepatocellular carcinoma. Circulating miRNA-221 in patients with hepatocellular carcinoma was higher compared with the control group, but the difference was not statistically significant. Receiver operating characteristic analysis revealed that the diagnostic power of miRNA-122a was suboptimal compared with serum alfa-fetoprotein. Further, the serum alfa-fetoprotein and miRNA-122a combined classifier resulted in performance similar to that of alfa-fetoprotein alone.

CONCLUSION

The serum miRNA-122a level correlates with risk factors for hepatocellular carcinoma. However, use of miRNA-122a as a diagnostic tool for hepatocellular carcinoma is not superior to alfa-fetoprotein. Further analysis is needed to evaluate the diagnostic power of plasma miRNA-122a for hepatocellular carcinoma.