Static magnetic field reduces cisplatin resistance via increasing apoptosis pathways and genotoxicity in cancer cell lines.

Cisplatin is a chemotherapy drug widely used in cancer treatment. Alongside its clinical benefits, however, it may inflict intolerable toxicity and other adverse effects on healthy tissues. Due to the limitation of administering a high dose of cisplatin as well as cancer drug resistance, it is necessary to utilize new methods optimizing treatment modalities through both higher therapeutic efficacy and reduced administered doses of radiation and drugs. In this study, sensitive (A2780) and resistant (A2780CP) ovarian carcinoma cells underwent treatment with cisplatin + static magnetic field (SMF). First, the levels of genotoxicity after treatment were evaluated by Comet assay. Then, cell cycle analysis and apoptosis assay were conducted by a flow cytometer. Lastly, the expression levels of genes involved in apoptosis and cellular drug uptake were investigated by PCR. After treating different groups of cells for 24, 48, and 96 h, the co-treatment of SMF and cisplatin as a combination managed to increase the amount of DNA damage in both sensitive and resistant cell lines. A considerable increase in mortality of cells was also observed mostly in the form of apoptosis, which was caused by inhibition of the cell cycle. The combination also increased the expression levels of apoptotic genes, namely P53 and P21; however, it did not have much effect on the expression levels of BCL2. Besides, the levels of CTR1 gene expression increased significantly in the groups receiving the aforementioned combination. Our study suggests that the combination of cisplatin + SMF might have clinical potential which needs further investigations through future studies.

Terpene-loaded Liposomes and Isopropyl Myristate as Chemical Permeation Enhancers Toward Liposomal Gene Delivery in Lung Cancer cells; A Comparative Study.

Gene therapy is in its development stage as a novel method for cancer treatment. Liposomes look promising as gene delivery vectors; however, investigations have shown that these vesicles are not doing well in some cases. It was decided here to investigate the possibility of augmentation of liposomal gene delivery by chemical penetration enhancers. Cationic liposome containing antisense oligonucleotide (AsODN) against lung cancer was prepared by ethanol injection method. Liposomal cineole and limonene (as enhancers) were prepared by film hydration method. Isopropyl myristate (IPM) was also investigated as penetration enhancer. Liposomes were evaluated for their size, zeta potential and encapsulation efficiency. Cancer cells (A549) were pretreated with liposomal terpenes prior to treatment with liposomal antisense or scrambled oligonucleotide. Cell viability was evaluated by MTT assay. Oligonucleotide -containing liposome showed particle size of about115 nm and zeta potential of 0.6 mV. Liposomal cineole significantly (P<0.05) increased specific activity of liposomal antisense but limonene didn't show such an effect. IPM increased both specific and non-specific cytotoxicity of Oligonucleotide. These results show that penetration enhancers (such as cineole) may be used for improving liposomal gene delivery and to reduce non-specific toxicity. Concentration and chemical nature of enhancer has prominent effect in their efficacy.

Evaluation of mutagenicity of mebudipine, a new calcium channel blocker.

Mebudipine is a new dihydropyridine calcium channel blocker, synthesized in our laboratory, for treatment of hypertension. It has shown a better efficacy than other drugs in this group. For assessing the risks of this drug, certain safety tests in the preclinical stage have been performed. In this study mutagenic effect of mebudipine was evaluated using Ames assay that could assess the mutagenicity of drugs and their metabolites using liver enzymes (S-9 mix). This procedure is approved as a predictive test, with a high predictive value. Salmonella TA102 (Ames assay) was used with and without S-9 in this study. For preparing S-9 mix, rat liver enzymes induced by phenobarbital were separated in KCl 0.154 M (0.154 M), as the solvent. Mebudipine was dissolved in polyethylenglycol 400. Mutagenicity test was performed in 6 doses from 39 µg to 1250 µg per every plate, in the presence and absence of the S-9 mix. The positive control sodium azide was dissolved in a dose of 5 µg/plate dissolved in polyethylenglycol 400 and negative control was polyethylenglycol 400 with no added agent. The colony counts of all doses in plates with S-9 were between 200-400 and in plates without S9 was between100-300. The colony counts in both states (with and without S-9) of all doses were in the range suggested by Ames assay for the safe drugs and were different from the positive control groups and equal to the negative controls. Mebudipine and its metabolites were not found to be mutagen on Salmonella TA102, based on Ames assay.