Regulative function of extracellular regulated protein kinases and telomerase in apoptosis of hepatocarcinomatous and leukemic cell lines / 中国实验血液学杂志

ABSTRACT

In order to investigate the change of telomerase activity and phosphorylated (activated) extracellular regulated protein kinases (ERK) 1 and 2 in hepatocarcinomatous cell line SMMC7721 and leukemic cell line K562 proliferation inhibition and apoptosis, three kinds of chemotherapeutic drugs harringtonine (HRT), vincristine (VCR) and etoposide (VP-16) were selected as inducers; and MTT assay, flow cytometry analysis, telomeric repeat amplification protocol (TRAP) assay and bioluminescence analysis were used. The results showed that after treatment of HRT, VCR and VP-16 for 24 hours, the cell proliferation was inhibited, apoptosis was induced, and telomerase activity and the protein expression of phosphorylated ERK1/2 were down-regulated. In HRT treated groups, the descendent grade was the most obvious. It was concluded that the common molecular mechanism of these chemotherapeutic drugs killing SMMC7721 and K562 cell lines might be through inhibiting ERK signal transduction pathways, cutting down ERK activity, reducing the transcription of target genes of ERKs, then indirectly down-regulate telomerase activity, and cell apoptosis is the final result of durative loss of telomere.