A novel report of apoptosis in human lung carcinoma cells using selective agonist of D2-like dopamine receptors: a new approach for the treatment of human non-small cell lung cancer.

In our previous study, a relationship between low expression of D2-like dopamine receptor genes and non-small cell lung cancer (NSCLC) disease was found. In this new research, by using selective agonist of these receptors, Bromocriptine (BR), we attempted to activate D2-like expression and apoptotic induction in a selective cell line of NSCLC. In addition, the relationship of apoptotic response of human lung carcinoma cells to BR and D2- dopamine receptor genes is investigated. Human lung cancer (QU-DB) cells were treated by five doses of BR at 48 h and cell viability was determined by MTT assay. The gene expression pattern of D2-like dopamine receptor Genes was studied by Real Time PCR. Nuclear morphology of cells was monitored by DAPI flourescent staining then induction of DNA fragmentation by BR was shown in an agarose gel. Finally, the detection and quantification of apoptosis and its differentiation from necrosis was carried out by using Annecxin-V-Fluos Staining. In this study, it is demonstrated that BR inhibited the proliferation of human lung cancer cells and induced apoptosis in them. In addition, the probable relationship between D2-dopamine receptor genes expression and the development of apoptosis was found. In conclusion, BR is responsible for induction of apoptosis in human lung cancer cells and can be used in treatment of these tumoric cells. In addition, normal expression of D2 dopamine receptors was associated with apoptotic effect of BR on these cells.

Induced apoptosis in human prostate cancer cells by blocking of vascularr endothelial growth factor by siRNA

INTRODUCTION: Vascular endothelial growth factor (VEGF) regulates several cell functions including; proliferation, differentiation, permeability, vascular tone, and the production of vasoactive molecules. The purpose of this study was to evaluate the potency of specific short-interfering RNA (siRNA) to suppress human VEGF expression by siRNA and investigate the effects of VEGF down-regulation on the cell proliferation and apoptosis of the human prostate cancer cell lines DU-145. METHODS: Transfection was performed using X-tremeGENE siRNA transfection reagent. At different time intervals, transfected cells were harvested and total RNA was extracted for RT-PCR. The VEGF content in supernatants were measured by ELISA. Inhibition of cell growth by hVEGF-siRNA was measured by using cell proliferation ELISA BrdU assay. Apoptotic cells were evaluated by using annexin-V-FITC apoptotic detection method. RESULTS: Transfection of hVEGF-siRNA resulted in statistically significant inhibition of hVEGF-mRNA that in turn caused a marked reduction in the expression of hVEGF. The cell growth was assessed every 24 h for 4 days after siRNA treatment resulted in a marked inhibition of cell proliferation as compared to scramble siRNA. The results of apoptosis showed that approximately 15 % of the cells treated with control-siRNA manifested evident apoptotic changes after 24 hpt, whereas DU-145 cells treated with hVEGF-siRNA significantly were positive, that is to say, 53 % at 72 hpt 23.9 ± 2.78 % (P < 0.001) and 13 ± 1.57 % at 96 hpt. CONCLUSION: Our findings indicate that siRNA are effective in eliciting the RNAi pathway in cancerous cells and that specific siRNA efficiently down-regulate VEGF expression. They could decrease VEGF production and induce apoptosis, which may also be linked to the inhibition of cancerous cell proliferation. Therefore, it can be concluded that siRNA-mediated suppression of VEGF represents a powerful tool against prostate cancer cell proliferation. VEGF down-regulation exerts a direct anti-apoptotic function in the DU-145 cell lines and promises the development of drugs for cancer therapy (AU)

Induced apoptosis in human prostate cancer cells by blocking of vascular endothelial growth factor by siRNA.

INTRODUCTION: Vascular endothelial growth factor (VEGF) regulates several cell functions including; proliferation, differentiation, permeability, vascular tone, and the production of vasoactive molecules. The purpose of this study was to evaluate the potency of specific short-interfering RNA (siRNA) to suppress human VEGF expression by siRNA and investigate the effects of VEGF down-regulation on the cell proliferation and apoptosis of the human prostate cancer cell lines DU-145. METHODS: Transfection was performed using X-tremeGENE siRNA transfection reagent. At different time intervals, transfected cells were harvested and total RNA was extracted for RT-PCR. The VEGF content in supernatants were measured by ELISA. Inhibition of cell growth by hVEGF-siRNA was measured by using cell proliferation ELISA BrdU assay. Apoptotic cells were evaluated by using annexin-V-FITC apoptotic detection method. RESULTS: Transfection of hVEGF-siRNA resulted in statistically significant inhibition of hVEGF-mRNA that in turn caused a marked reduction in the expression of hVEGF. The cell growth was assessed every 24 h for 4 days after siRNA treatment resulted in a marked inhibition of cell proliferation as compared to scramble siRNA. The results of apoptosis showed that approximately 15 % of the cells treated with control-siRNA manifested evident apoptotic changes after 24 hpt, whereas DU-145 cells treated with hVEGF-siRNA significantly were positive, that is to say, 53 % at 72 hpt 23.9 ± 2.78 % (P < 0.001) and 13 ± 1.57 % at 96 hpt. CONCLUSION: Our findings indicate that siRNA are effective in eliciting the RNAi pathway in cancerous cells and that specific siRNA efficiently down-regulate VEGF expression. They could decrease VEGF production and induce apoptosis, which may also be linked to the inhibition of cancerous cell proliferation. Therefore, it can be concluded that siRNA-mediated suppression of VEGF represents a powerful tool against prostate cancer cell proliferation. VEGF down-regulation exerts a direct anti-apoptotic function in the DU-145 cell lines and promises the development of drugs for cancer therapy.

Downregulation of telomerase activity in human promyelocytic cell line using RNA interference.

Telomerase is a ribonucleoprotein complex. It consists of two main components, human telomerase reverse transcriptase (hTERT) and human telomerase RNA. High telomerase activity is present in most malignant cells, but it is barely detectable in majority of somatic cells. The direct correlation between telomerase reactivation and carcinogens has made hTERT a key target for anticancer therapeutic studies. In this study, for the first time, we evaluated the ability of the new generation of short interfering RNA (siRNA) to regulate telomerase activity in the human promyelocytic leukemia cell line (HL-60). Transient transfection cell line by hTERT siRNAs resulted in statistically significant suppression of hTERT messenger RNAs which were detected by quantitative real-time polymerase chain reaction, while the expressed hTERT protein levels were measured by flow cytometry. The results of telomeric repeat amplification protocol showed that telomerase activity was significantly reduced upon transfection of the HL-60 cell line with hTERT siRNAs. The results of this study showed that telomerase activity and cell proliferation were efficiently inhibited in the hTERT siRNA-treated leukemic cell line.

A simplified purification procedure for recombinant human granulocyte macrophage-colony stimulating factor from periplasmic space of Escherichia coli.

Cytoplasmic expression is commonly used for production of recombinant human granulocyte macrophage-colony stimulating factor (rhGM-CSF) which most often comes with inclusion body formation. We expressed rhGM-CSF in periplasmic space of Escherichia coli and optimized its extraction by osmotic shock and purification by anion exchange chromatography. Our works show that MgCl2 at 2 mM in osmotic shock buffer improves extraction of the protein and reduces contamination with other proteins. To achieve a simplified purification procedure for rhGM-CSF, efforts were focused on the adjustment of pH of the buffers and application of proper concentration of salt. Following to measurement of the pI of 5.4 for rhGM-CSF by isoelectric focusing, the pH of dialysis buffer and buffers used in anion exchange chromatography were adjusted to 6.5 for optimal binding of the protein to the column and removal of proteins with higher pIs during washing of the column. In addition, it was found that appliance of NaCl at a concentration of 20 mM in dialysis and column washing buffers prior to elution with elution buffer containing 120 mM NaCl significantly improves purification of the protein. Starting with specific amount of total proteins obtained by osmotic shock, it was possible to recover 95% of which following to purification with a purification yield of 72% for rhGM-CSF along with appropriate biological activity.

Cytotoxic effects of pyocin S2 produced by Pseudomonas aeruginosa on the growth of three human cell lines.

Pyocin typing of 82 Pseudomonas aeruginosa strains, collected from different Iranian clinical sources, revealed that one isolate, P. aeruginosa 42A, produced pyocin S2, a protease-sensitive bacteriocin. Pyocin S2 production was induced by mitomycin C (2 micro g/mL) in the pyocin S2 producer P. aeruginosa 42A. Pyocin S2 was purified using ion exchange chromatography with CM-Sepharose CL-6B and sodium phosphate buffer (pH 8) from an 80% ammonium sulfate precipitate of whole-cell lysates. Pyocin activity of the fractions was detected using the Govan spot testing method. The purity of the active fraction was confirmed by SDS-PAGE, where a single band with a molecular mass of 74 kDa was detected. Cytotoxic effects of purified pyocin S2 and partially purified pyocin from P. aeruginosa 42A on the human tumor cell lines HepG2 and Im9 and the normal human cell line HFFF (Human Foetal Foreskin Fibroblast) were studied by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The results demonstrated that partially purified pyocin and pyocin S2 exhibited substantial inhibitory effects on the growth of the tumor cell lines HepG2 and Im9, while no inhibitory effects were observed on the normal cell line HFFF. Pure lipopolysaccharide was used as a control and was found to have no inhibitory effect on any of the cell lines tested.