MicroRNAs (miRNAs) play a key role in tumor metastasis based on their capacity to regulate the expression of tumor-related genes. Over-expression of key genes such as c-MYC and CTNNB1 (encoding β-catenin) in Wnt/β-catenin-dependent and ROCK1 in Wnt/β-catenin-independent signaling pathways (Rho/Rho-associated kinase (ROCK) signaling pathway) has already been identified as the hallmarks of many tumors, and their role in breast cancer has also been investigated and confirmed. miR-340 characterization as an onco-suppressor miRNA has been previously reported. However, the mechanism by which it inhibits metastasis has not been completely elucidated. Quantitative real-time PCR (qPCR), Western blot, and luciferase assays were used to confirm the effect of miR-340 on the 3'-untranslated region (UTR) of the target genes. Lentiviral particles containing miR-340 were also used to evaluate the effect of miR-340 restoration on cell proliferation, migration, and invasion in vitro in the invasive MDA-MB-231 cell line. By applying bioinformatic approaches for the prediction of miRNAs targeting 3'-UTRs of CTNNB1, c-MYC, and ROCK1, we found out that miR-340 could dramatically down-regulate metastasis by targeting Wnt signaling in breast cancer cells. In the current study, analyzing miR-340 by reverse transcription quantitative PCR (RT-qPCR) in MDA-MB-231 showed that it was remarkably down-regulated in the metastatic breast cancer cell line. We found that restoration of miR-340 in the invasive breast cancer cell line, MDA-MB-231, suppresses the expression of the target genes' messenger RNA (mRNA) and protein and, as a result, inhibits tumor cell invasion and metastasis. Our findings highlight the ability of bioinformatic approaches to find miRNAs targeting specific genes. By bioinformatic analysis, we confirmed the important role of miR-340 as a pivotal regulator of breast cancer metastasis in targeting previously validated (ROCK1) and potentially novel genes, i.e., (CTNNB1 and c-MYC).
The heterogeneous and multifactorial essence of polycystic ovary syndrome (PCOS) renders a remarkable significance to microRNAs (miRNAs). Normo-androgenic (NA) and hyperandrogenic (HA) PCOS patients were compared with matched healthy women. Expression of miRNAs and TGFβ signaling genes was studied by qRT-PCR and western blotting. Effect of androgen on expression of miR-93 and miR-21 and involvement of androgen receptor were appraised. In granulosa cells (GCs), miR-93 and miR-21 showed significantly increased levels in HA patients compared to NA patients. On the contrary, follicular fluid (FF) levels of both miRNAs were significantly decreased in HA group compared to control women. No significant change in the expression of miRNAs in serum samples was detected. Furthermore, mRNA levels of SMAD7 and TGFBR2 were significantly downregulated in GCs of HA group compared to NA and control subjects. TGFBR2 protein level was significantly decreased in HA patients compared to controls. Free testosterone and free androgen index were positively correlated with expression of miR-93 and miR-21 in GCs of PCOS group. Our findings show distinct molecular signature of different subtypes of PCOS. Intermediary position of miRNAs as androgen responsive factors may play critical role in the pathogenesis of PCOS in hyperandrogenic condition.
Development of a rapid and accurate quantification method for the detection of microRNAs (miRNAs) has been desired, in particular, when they are differently expressed in normal and pathological conditions. However, various methods for the quantification of small non-coding RNAs as well as miRNAs have been described. These methods mainly include hybridization-based approaches such as primer extension, northern blotting, microarray profiling, and reverse transcription (RT) PCR. Here, we developed a simple and rapid method based on stem-loop primer-based real-time PCR assay for sensitive and accurate detection of mature miRNAs. Initially, a miRNA-specific stem-loop RT primer is used for RT, which is followed by TaqMan real-time PCR assay using specific forward primer in combination with universal reverse primer and TaqMan probe. The assay has shown high sensitivity (≤50 copies/reaction) for miRNA detection in two breast cancer cell lines, MCF-7 and MDA-MB-231. This assay might be implicated as a rapid and cost effective method for the detection of small non-coding RNAs.
There is growing evidence of a malignancy-protective role for vitamin D in breast cancer. The effects of vitamin D are mediated via the vitamin D receptor (VDR) which is encoded by VDR gene. Several SNPs on VDR gene has attracted research interest, although the magnitude of the impact of VDR allelic variations on breast cancer has been controversial. In the present study, we focused on the distribution of VDR FokI and BsmI polymorphisms in Iranian breast cancer patients. A case-control study was conducted on 296 samples including 140 breast cancer patients and 156 age matched control women. Restriction fragment length polymorphism (RFLP) analysis was performed for BsmI and FokI genotyping. Randomly selected PCR products were subjected to sequencing to verify the RFLP results. A significantly increased risk of breast cancer was observed with BsmI bb or even Bb genotype (OR 2.39, CI 1.17-4.85 and OR 2.28, CI 1.16-4.47, respectively). Nevertheless, statistically significant association between FokI genotypes and breast cancer risk was not observed. This study lends support for an increased risk of breast cancer associated with the VDR BsmI polymorphism.
B cell chronic lymphocytic leukemia (B-CLL) is a chronic leukemia manifested by increased numbers of B cells in circulation. The slow, smouldering nature of the disease in a significant proportion of the cases makes it an ideal target for immunotherapy. Dendritic cell (DC)-based immunotherapy is emerging as an exciting modality with significant clinical potential. In this study, three strategies for delivering antigens to DC, namely apoptotic bodies (Apo-DC), tumor lysates, and tumor RNA were studied in an autologous setting. In all six CLL patients, Apo-DC induced higher HLA-restricted, T cell responses than DC pulsed with tumor lysate or RNA. Real-time PCR confirmed higher expression of genes for IL-2 and IFN-c in T cells stimulated with Apo-DC. Concurrently, no IL-10 and low IL-4 responses indicated that the immune response was primarily of the Th1 type. Enzyme-linked immunospot assay revealed high IFN-c secretion by T cells when Apo-DC was used to stimulate autologous T cells in all patients. Our data suggest that cellular vaccines with DC loaded with apoptotic bodies may be a suitable approach for immunotherapy of B-CLL.
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