RESUMEN
miRNA are short non-coding RNA which inhibit translation of mRNA. miRNA regulate several cellular processes. Certain miRNA are known to induce oncogenesis. miRNA can be measured by real-time PCR and be imaged using a combination of in situ hybridization (ISH) and quantum dots (QD). The advantage of using quantum dots is that several miRNA can be simultaneously measured using multiplexed QD. Additionally, miRNA can be visualized in different regions of the tissue. Since miRNA are biomarkers of various disease states, miRNA can be visualized and quantitated in tissue sections for diagnostic and prognostic purposes. Here we describe ISH-QD analysis of tissue sections. Tissue sections from xenografts or clinical specimens are used. These are deparaffinized, treated with Proteinase K and hybridized with a biotin-probe to specific to the miRNA. The in situ hybridization is performed by labeling the biotin-probes and followed by labeling with streptavidin tagged quantum dots. Image acquisition of the quantum dots is performed and analyzed for the miRNA expression levels. Combining ISH and QD gives a powerful tool to detect miRNA in different cells of the tissue.
RESUMEN
Cancer cells and cancer associated stromal cells co-evolve secrete extracellular vesicles to the surrounding regions and regulate several processes involved in cancer metastasis. miRNAs have been known to be mediators of cancer progression and metastasis. miRNAs consist of short noncoding RNA. miRNAs are stable in extracellular fluids such as serum, plasma and urine. miRNAs are secreted by cells in normal and diseased conditions. miRNAs signatures have been identified specific to certain disease conditions. Therefore they are valuable biomarkers for different diseases. In our study we identified certain miRNAs, miR-409-3p and miR-409-5p, which were secreted by activated stromal fibroblast cells and were taken up by cancer cells to induce explosive tumor growth, through activation of epithelial to mesenchymal transition of cancer cells. Here we describe a procedure to determine miRNAs (miR-409-3p and miR-409-5p) in extracellular vesicles, which were secreted by prostate cancer stromal cells expressing miR-409. In this procedure, conditioned media from the stromal fibroblasts was used to extract the vesicular fraction. RNA was purified from the vesicular fraction, and specific miRNA was reverse transcribed and quantitated using real-time PCR assay.
RESUMEN
BACKGROUND: Advanced renal cell carcinoma (RCC) frequently develops skeletal metastasis and is highly resistant to conventional therapies. We hypothesized that the osteocalcin (OC) promoter may be a promising gene delivery system for RCC targeted gene therapy because osteotropic tumors gain osteomimetic properties and thrive in the new environment by exhibiting a bone-like gene expression profile. Human OC (hOC) expression is highly regulated by vitamins and hormone. In the present study, we tested the feasibility of vitamin-regulatable hOC promoter for RCC-specific transcriptional targeting, and examined the anti-tumor effect of vitamins C and D3 with hOC-based adenoviral vectors towards RCC. METHODS: Real-time reverse transcriptase-polymerase chain reaction measured OC expression induced by vitamins C and D3, either alone or in combination, in RCC and normal human renal epithelial cells (HRE). The RCC-cytotoxic effects of concomitant vitamins and hOC promoter-based adenoviral vectors, Ad-hOC-TK and Ad-hOC-E1, were evaluated in both cell culture and a xenograft murine model. RESULTS: We found that high doses of vitamin C induced H2O2-dependent apoptosis in RCC but not HRE. Treatment of RCC cells with combined vitamins C and D3 treatment significantly increased OC promoter activity compared to single reagent treatment. Combined vitamin therapy reduced tumor size (85%) and complete tumor regression occurred in 38% of mice co-administrated Ad-hOC-E1. CONCLUSIONS: The results obtained in the present study demonstrate that vitamins C and D3 synergized with the anti-tumor effects of therapeutic genes driven by hOC promoter through direct cytotoxicity as well as transcriptional targeting. This combined gene therapy provides a promising modality for advanced RCC targeted therapy.
