N regular human lymphocytes. The majority of normal human cells have
N normal human lymphocytes. The majority of normal human cells have no detectable telomerase activity, however, activity is generally detected in cancer cells. As a result, inhibiting telomerase activity and inducing apoptosis may well possess a selective impact on cancer cells. The aim with the present study was to investigate the inhibitory effects of telomerase activity by CAUE within a NALM-6 cell culture system. CAUE was shown to preferentially damage DNA synthesis compared with RNA or protein synthesis. Additionally, telomerase activity was significantly suppressed as well as the activity of human telomerase reverse transcriptase (hTERT), a subunit of telomerase, was decreased following remedy with CAUE, each and every inside a concentration-dependent manner. These results indicated that the cytotoxic effects of CAUE are mediated by the inhibition of DNA synthesis and telomerase activity. The present study is the very first to identify the cytotoxic mechanisms of CAUE in leukemia cells. Introduction Telomerase, a specialized ribonucleoprotein, plays an essential function in cell proliferation by defending against the issue of end-replication by adding TTAGGG repeats to telomeres (1). The majority of normal human cells have no detectable telomerase activity, having said that, activity is normally detected in cancer cells (2,three). The inhibition of telomerase causes a progressive and essential reduction of telomeres, leading to a potent signal for the blockage of cell proliferation plus the induction of apoptosis (4). Targeting the inhibition of telomerase activity plus the induction of apoptosis may perhaps have a selective impact on cancer cells. Clinically, B-cell acute lymphoblastic leukemia is curable, nevertheless, 50 of adults experience therapy failure as a consequence of drug resistance and also the inability of older adults to tolerate the side-effects of therapy (five). Consequently, it can be desirable to create novel p38β custom synthesis anticancer drugs against B-cell leukemia, such as these targeting the inhibition of telomerase activity, to prevent side-effects following chemotherapy. Our prior study reported that remedy with caffeic acid undecyl ester (CAUE), a novel caffeic acid derivative, decreased cell survival in human B-cell leukemia NALM-6 cells, but exhibited no considerable effect on the survival of typical lymphocytes. Moreover, the cytotoxic induction mechanisms of CAUE were shown to become involved inside the intrinsic apoptotic pathway within a caspase-dependent manner (six). The present study focused on the inhibitory effects of telomerase activity by CAUE inside a NALM-6 cell culture program. Supplies and approaches Materials and cell culture. CAUE was prepared as described previously (7). All other reagents, unless otherwise stated, were of your highest grade available and purchased from Sigma-Aldrich (St. Louis, MO, USA) or Wako Pure 5-HT2 Receptor Agonist medchemexpress Chemical Industries, Ltd. (Osaka, Japan). Antibodies against human telomerase reverse transcriptase (hTERT; rabbit polyclonal; Santa Cruz Biotechnology, Inc., Santa Cruz, CA USA) and -actin as the loading manage (rabbit polyclonal; Cell Signaling Technologies, Inc., Danvers, MA, USA) had been made use of. Human B-cell leukemia NALM-6 cells were supplied by the Cell Resource Center for Biomedical Research (Tohoku University, Sendai, Japan). Cell culture reagents have been obtained from Invitrogen Life Technologies (Carlsbad, CA, USA) and also the cells had been routinely cultured working with regular strategies, as described previously (eight,9). DNA, RNA and protein synthesis assays. The impact of CAUE on the synthesis of DNA.