Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.4.2.30 (PARP)
 13,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although attempts have been made to treat undifferentiated thyroid carcinoma using multidisciplinary therapeutic procedures including surgery, radiotherapy, and chemotherapy, the prognosis of undifferentiated thyroid carcinoma remains quite poor. New approaches to increase the sensitivity of patients to anticancer drugs and radiation will be needed to improve the survival rate for undifferentiated thyroid carcinoma. We examined the effect of Bcl-2 antisense oligonucleotide on drug-sensitivity in association with apoptosis in the 8305C undifferentiated thyroid carcinoma cell line. The drug sensitivity was evaluated by MTT assay for 48 h, while apoptosis was assessed according to the formation of internucleosomal DNA ladders. The Bcl-2 antisense was introduced into 8305C cells by using a 18-mer phosphorothioate oligonucleotide by lipopolyamine-mediated transfection twice for 12 h. The expression of apoptosis genes was assessed by Western blotting. The 8305C cells were sensitive to adriamycin (ADM), mitomycin (MMC), docetaxel (TXT), and paclitaxel (TXL), showing mean IC50 values of 0.72, 1.1, 1.3, and 4.1 microM, respectively. In contrast, the 8305C cells were resistant to cisplatin (CDDP) and 5-fluorouracil (5-FU), with mean IC50 values of 42.0 and 48.0 microM, respectively. Treatment with Bcl-2 antisense suppressed the protein level of Bcl-2 in 8305C cells in a dose-dependent manner up to 1.0 microM. Drug-sensitivity was increased by pretreatment with Bcl-2 antisense as assessed by the IC50 (x-fold): 0.48 (1.5-fold) in ADM; 0.42 (2.6-fold) in MMC, 0.56 (2.3-fold) in TXT, 1.5 (2.7-fold) in TXL, 8.6 (4.9-fold) in CDDP, and 25.0 (1.9-fold) in 5-FU, respectively. The increased drug-sensitivity was associated with the induction of apoptosis-related proteins, Fas, caspase 8, cytochrome c, caspase 3, and to subsequent apoptosis, as determined by the formation of internucleosomal DNA ladders and PARP in the treated cells. Susceptibility in apoptotic cell death following treatment with anticancer drugs was associated with induction of apoptosis-related genes in undifferentiated thyroid carcinoma cells, and induction of apoptosis was enhanced by pretreatment with Bcl-2 antisense oligonucleotide. These results imply a potential new strategy targeting an antiapoptotic protein, Bcl-2, by its antisense oligonucleotide for enhancement of chemotherapeutic efficacy in undifferentiated thyroid carcinomas.
 ...
PMID:Effect of Bcl-2 antisense oligonucleotide on drug-sensitivity in association with apoptosis in undifferentiated thyroid carcinoma. 1273 25

Taxotere is a cytotoxin effective in treating breast and prostate cancer. It stabilizes microtubules and causes catastrophic cell cycle arrest in G2/M. Taxanes also initiate apoptosis by activating signal pathways, such as the jun N-terminal kinase (JNK) pathway. Strategies aimed at potentiating cell death signaling may improve their efficacy while lessening the potential side effects. We reported that all-trans retinoic acid (ATRA) potentiated taxane-mediated cell death. Here we investigated whether ATRA potentiates cell death signaling through the JNK pathway. Activation of JNK by Taxotere 0.01, 0.1 and 1.0 microM was observed at 24 h in adherent cells and increased at 48 h. Taxotere 0.001 microM-induced JNK activation started after 48 h and increased at 72 h. The timing and intensity of PARP cleavage was similar to that of JNK activation. JNK activation and PARP cleavage induced by 30 nM Taxotere at 48 h were reversed by curcumin, PD169316 and SP600125, JNK inhibitors in order of progressive specificity. None of these inhibitors had an effect on p38 or ERK phosphorylation. All three inhibitors reversed Taxotere-induced phosphorylation of Bcl-2. ATRA induced JNK activation at 24, 48 and 72 h. Incubating cells with ATRA 0.01 microM for 3 days prior to Taxotere treatment potentiated Taxotere-induced JNK activation 24 and 48 h later, an effect sustained for 72 h. Cytotoxicities from 3-day ATRA 0.01 microM incubations were synergistic with subsequent 1-h Taxotere 0.01, 0.1 and 1.0 microM incubations in breast cancer cell lines MCF-7 and MDA-MB-231 and in prostate cancer cell lines LNCaP and PC-3, and additive in breast cancer cell line SK-Br-3. These data demonstrate the potentiation of Taxotere-induced cell death by ATRA pretreatment in breast and prostate cancer cells, and support a mechanism through accentuated and sustained JNK activation.
 ...
PMID:All-trans retinoic acid potentiates Taxotere-induced cell death mediated by Jun N-terminal kinase in breast cancer cells. 1472 71

Docetaxel (Taxotere, DTX) is a promoter of apoptosis in cancer cells. Since cytotoxic mechanisms of DTX are not yet fully understood, we have investigated the effects of DTX on apoptosis and ras-->Erk-mediated signal transduction in human epidermoid KB, colon HT-29 and breast HCC1937 cancer cells. We have found that the exposure to 0.78 or 1.56 or 2.5 ng/ml DTX for 48 h induced apoptosis and growth inhibition in about 50 % of KB, HCC1937 and HT-29 cell population, respectively. In these experimental conditions, PARP and caspase 3 cleavage was also showed in all cell lines. KB and HCC1937 cells express a wild type p53 while HT-29 display a mutated form. Interestingly, we have found that DTX reduces the expression of mutated p53 in HT-29 and increases the expression of wild type in KB and HCC1937 cells. Moreover, DTX reduces ubiquitination of the wild type p53 in KB and HCC1937 cells and increases the ubiquitin-conjugated form of mutated p53 in HT-29 cells. Furthermore, exposure of cancer cells to DTX for 48 h increases the expression and activity of Ras and up-regulates Raf-1 and the phosphorylated isoforms of Erk-1/2. On the bases of these data, we have hypothesized that the increased activity of the ras-->erk-dependent pathway induced by DTX could be a protective signalling from the apoptosis caused by the drug. Therefore, we have used R115777, a farnesyl transferase inhibitor that inactivates ras, in combination with DTX. The combined treatment with DTX and R115777 resulted in a strong synergism in growth inhibition in the three cell lines. These data suggest the use of the combination in these therapeutic settings even if further experiments are required for the clinical translation.
 ...
PMID:Docetaxel induces p53-dependent apoptosis and synergizes with farnesyl transferase inhibitor r115777 in human epithelial cancer cells. 1597 May 18