RESUMEN
It has previously been shown that anthranilamide-pyrazolo[1,5-a]pyrimidine conjugates activate p53 and cause apoptosis in cervical cancer cells such as HeLa and SiHa. Here we establish the role of these conjugates in activating p53 pathway by phosphorylation at Ser15, 20 and 46 residues and downregulate key oncogenic proteins such as MYCN and Mdm2 in IMR-32 neuroblastoma cells. Compounds decreased the proliferation rate of neuroblastoma cells such as IMR-32, Neuro-2a, SK-N-SH. Compound treatment resulted in G2/M cell cycle arrest. The expression of p53 dependent genes such as p21, Bax, caspases was increased with concomitant decrease of the survival proteins as well as anti-apoptotic proteins such as Akt1, E2F1 and Bcl2. In addition the expression of important microRNAs such as miR-34a, c, miR-200b, miR-107, miR-542-5p and miR-605 were significantly increased that eventually lead to the activation of apoptotic pathway. Our data revealed that conjugates of this nature cause cell cycle arrest and apoptosis in IMR-32 cells [MYCN (+) with intact wild-type p53] by activating p53 signalling and provides a lead for the development of anti-cancer therapeutics.
Asunto(s)
Antineoplásicos/química , MicroARNs/metabolismo , Pirazoles/química , Pirimidinas/química , ortoaminobenzoatos/química , Antineoplásicos/síntesis química , Antineoplásicos/toxicidad , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica , Células HeLa , Humanos , Puntos de Control de la Fase M del Ciclo Celular/efectos de los fármacos , Proteína Proto-Oncogénica N-Myc , Neuroblastoma/metabolismo , Neuroblastoma/patología , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Oncogénicas/antagonistas & inhibidores , Proteínas Oncogénicas/genética , Proteínas Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-mdm2/genética , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Purinas/química , Purinas/toxicidad , Roscovitina , Proteína p53 Supresora de Tumor/antagonistas & inhibidores , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
MicroRNAs are endogenously expressed tiny non-coding RNAs that control gene expression at the post-transcriptional level and regulate processes of cell growth, differentiation, proliferation and apoptosis. Aberrant expression of microRNAs correlates with various cancers. Our experiments demonstrated that imidazo-benzothiazole conjugates caused apoptosis in colon cancer cells by modulating the expression of microRNAs. In vivo study in Drosophila melanogaster has exhibited inhibitory action on bantam microRNA, the homolog of human miR-542-5p that is involved in deciding the cellular cues that regulate the balance between proliferation and apoptosis. The expression of direct targets of bantam such as Hid and HDAC-6 were affected upon compound treatment. Interestingly, these conjugates downregulate the genes involved in microRNA biogenesis such as Drosha, Pasha and Dicer-1. Our findings have elucidated the microRNA inhibitory role of imidazo-benzothiazole conjugates.