RESUMEN
Today, drug resistance is one of the major problems in fight against cancer. Therefore, combination of therapeutic strategies was raised to effectively improve disease prognosis. In this regard, silver nanoparticles (AgNPs) are considered significant due to their anticancer properties. This study aimed to return sensitivity to cisplatin to A2780 cisplatin-resistance cell lines in the presence of biogenic synthesis curcumin-coated silver nanoparticles (cAgNPs). Synergic cellular effects of cAgNPs and cisplatin on ovarian carcinoma 2780 resistant to cisplatin cells were assessed using MTT assay, Acridine orange (AO)/propidium iodide (PI), DAPI staining, Annexin V/PI assay, and caspase 3/9 activation assay. Finally, expression of p53 and MMP-9 genes were evaluated using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). According to the results, 8 µg/mL and 62 µg/mL of cAgNPs and cisplatin led to 50% cell death in 48 h, respectively. Therefore, we combined non-toxic concentration of nanoparticles (1-5 µg/mL) with cisplatin (2.5 µg/mL). Decreased proliferation rate was about 50% for synergic use of cisplatin (2.5 µg/mL) and cAgNPs (2 µg/mL). According to the results, cell death induction significantly increased by AO/PI, DAPI staining and Annexin V/PI assay in the combined group. Moreover, activity of caspase 3/9 significantly increased in the mentioned group. The combined use of cAgNPs and cisplatin resulted in upregulated expression of p53 gene and downregulated expression of MPP-9 gene. As observed in this study, a combination of cAgNPs and cisplatin increased the efficiency of apoptosis induction in A2780 cells, compared to the independent use of cisplatin or cAgNPs.
RESUMEN
BACKGROUND: Leukemia is distinguished by abnormal proliferation of leukocytes. Although there has been some progress in developing novel cancer therapies, no significant improvement was observed in the overall survival rate over the last decade. Selective cyclooxygenase-2 (COX-2) inhibitors are known to inhibit tumor growth by exerting antimetastatic and antiangiogenic effects through inhibition of COX -dependent and independent pathways. The ability of two new triaryl-oxadiazole derivatives, compounds A (3-(4-chlorophenyl) -5-(4-flurophenyl)-4-Phenyl-4,5-dihydro-1,2,4-oxadiazole) and B (3,5-bis(4-chlorophenyl)-4-Phenyl-4,5-dihydro-1,2,4-oxadiazole), to induce apoptosis in human erythroleukemia K562 cells was evaluated and the upstream mechanism was investigated. METHODS: K562 cells were treated with compounds A and B at their IC50 concentrations and analyzed by DAPI staining and Annexin-V-FLUOS labelling solution. Nuclear factor kappa-B (NF-κB) activation was evaluated by TransAM kit. Cyclooxygenase-2 (COX-2), Caspase-3, Bax, Bcl-2, ferritin heavy chain (FHC), extra cellular signal-regulated kinase (ERK), p-ERK and early growth response protein-1 (Egr1) levels were determined using Western blotting, while c-Myc mRNA level was investigated by RT-PCR. RESULTS: Changes in nuclear morphology and the increased annexin-V/PI staining revealed the apoptotic cell death in compounds A- and B-treated K562 cells. A significant reduction in NF-κB activity as well as FHC and p-ERK levels were detected in these cells. No change was observed in the levels of Bax, Bcl-2, Caspase-3, COX-2, c-Myc and Egr1, following treatment with the two compounds. Collectively, compounds A and B potentiate apoptosis as shown by DAPI staining, flowcytometry, FHC and p-ERK downregulation and NF-κB inactivation. CONCLUSION: Two compounds induce apoptosis in a COX-2-independent manner which also appears to be independent from mitochondria, caspase and c-Myc/Egr1 pathways.