Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.108 (TAT)
 2,389 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A combination of psoralen and ultraviolet A radiation (PUVA) is widely used in the treatment of psoriasis. However, PUVA treatment increases the risk of developing skin cancer in psoriasis patients and induces skin cancer in mice. Since the DNA damage induced by PUVA is quite different from that induced by UV, we investigated whether PUVA-induced mouse skin cancers display carcinogen-specific mutations in the p53 tumor suppressor gene. The results indicated that 10 of 13 (77%) PUVA-induced skin tumors contained missense mutations predominantly at exons 6 and 7. In contrast, tumor-adjacent, PUVA-exposed skin from tumor-bearing animals did not exhibit p53 mutation in exons 4-8. Interestingly, about 40% of all mutations in PUVA-induced skin tumors occurred at 5'-TA sites, and an equal number of mutations occurred at one base flanking 5'TA or 5'-TAT sites. Since PUVA induces DNA cross-links exclusively at these sites and since UV "signature" mutations were rarely detected in PUVA-induced skin cancers, we can conclude that PUVA acts as a carcinogen by inducing unique PUVA signature mutations in p53. This finding may have implications for identifying the etiology of skin cancer in psoriasis patients who have undergone PUVA therapy.
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PMID:Signature p53 mutation at DNA cross-linking sites in 8-methoxypsoralen and ultraviolet A (PUVA)-induced murine skin cancers. 875 85

The clinical and pathologic features of a rare case of follicular carcinoma with small foci of poorly differentiated and anaplastic carcinoma are presented. Eight years after the removal of the primary neoplasm, the patient developed pulmonary and brain metastases that were predominantly composed of the poorly differentiated and anaplastic components. A comparative immunohistochemical and molecular analysis of p53 status in the follicular, poorly differentiated and anaplastic components of the tumor was performed. p53 immunostaining was restricted to the poorly differentiated and anaplastic areas. Single strand conformation polymorphism analysis (SSCP-PCR) from DNA obtained by microdissection demonstrated the presence of a mutation (TAT-->TGT; Tyr-->Cys) in codon 220, exon six of the p53 gene in the anaplastic component, that was absent in the well-differentiated follicular areas. The results of that study in this rare tumor support that p53 has a tumor progression role in thyroid tumorigenesis.
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PMID:p53 in a thyroid follicular carcinoma with foci of poorly differentiated and anaplastic carcinoma. 918 95

A 60-year-old woman was admitted in June 1993, because of anemia and purpura and given a diagnosis of acute myelogenous leukemia with trilineage dysplasia. She entered partial remission (PR) after three courses of low-dose Ara-C and G-CSF, but never reached complete remission (CR) in spite of additional chemotherapy. In October 1994, the number of leukocytes, myeloblasts, and erythroblasts in the patient's peripheral blood increased, and her clinical condition deteriorated. The disease was resistant to other therapy. The patient had pneumonia and died of septic shock in December 1994. A chromosomal analysis performed on admission showed 46,XX,t(3;5) (q21;q31) [9/9]. As an additional chromosomal abnormality, deletion of the X chromosome was observed in January, 1994. Analysis of the p53 gene by the polymerase chain reaction-single strand conformation polymorphism method showed one base transposition, from TAT to TGT (Tyr to Cys), at codon 220 of exon 6. Karyotype evolution and p53 gene mutation were observed during the disease course and may have been related to progression of the disease.
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PMID:[t(3;5) (q21;q31) chromosomal abnormality in a patient with acute myelogenous leukemia with trilineage myelodysplasia]. 979 99

We devised two short peptides corresponding to amino acids 211-221 of human Cdc25C fused with a part of HIV1-TAT. These peptides inhibited hChk1 and Chk2/HuCds1 kinase activity in vitro and specifically abrogated the G2 checkpoint in vivo. These peptides sensitized p53-defective cancer cell lines to DNA-damaging agent to death without obvious cytotoxic effect on normal cells. Our results clearly indicate that the specific abrogation of the cell cycle G2 checkpoint is a feasible strategy for cancer therapy, and hChk1 and Chk2/HuCds1 are proper targets for that purpose.
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PMID:Sensitization of cancer cells to DNA damage-induced cell death by specific cell cycle G2 checkpoint abrogation. 1060 29

Two membrane transporters, the 17 amino acid (aa) oligopeptide penetratin derived from the homeodomain of Antennapedia (Ant) and an analogue of the basic domain of TAT (aa 47-57) (TAT-a) from HIV-1, were tested as carriers for a p53 C-terminal peptide (aa 361-382) into human breast cancer cells. The studies were performed to determine whether the membrane-transduction efficiency of membrane carriers: Ant, TAT or TAT analogue (TAT-a) correlated with peptide hydrophobic features. Peptide-sequence analysis clearly demonstrated that the Ant sequence and p53 peptide sequence (p53p) together created a peptide with enhanced hydrophobic characteristics; while the TAT or TAT analogue (TAT-a) and p53p sequence together created a peptide with significantly less hydrophobic qualities. The degree of hydrophobic moment and helical wheel plots for these peptides correlated directly with their ability to transduce the p53 peptide. Western blot analysis revealed that Ant was able to transduce p53 C-terminal peptide into human breast cancer cells as a highly efficient membrane transporter. Compared to Ant, TAT-a fused to the C-terminus of p53 peptide (p53p-TAT-a) was a less efficient carrier into these cells under the conditions of our study. Additionally, N-terminal linked TAT-a to p53p (TAT-a-p53p) showed even lower efficiency as a transporter than p53-TAT-a. Apoptosis assays showed that the p53 peptide, fused at its C-terminus to Ant (p53p-Ant), induced a higher percentage of apoptotic cells in human breast cancer cell lines expressing mutant or wild-type p53 as compared to p53 peptide fused at its C-terminus to the TAT-a sequence (p53p-TAT-a) or when fused at the N-terminus to TAT-a (TAT-a-p53p). These data suggested a direct correlation between hydrophobic characteristics and efficiency as a transporter. Sequence study, using hydrophobic moment and helical wheel analyses, may be useful predictive tools for choosing the best carrier for a peptide.
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PMID:Correlation between hydrophobic properties and efficiency of carrier-mediated membrane transduction and apoptosis of a p53 C-terminal peptide. 1241 61

Advanced-stage peritoneal carcinomatosis is resistant to current chemotherapy treatment and, in the case of metastatic ovarian cancer, results in a devastating 15%-20% survival rate. Therapeutics that restore genes inactivated during oncogenesis are predicted to be more potent and specific than current therapies. Experiments with viral vectors have demonstrated the theoretical utility of expressing the p53 tumor suppressor gene in cancer cells. However, clinically useful alternative approaches for introducing p53 activity into cancer cells are clearly needed. It has been hypothesized that direct reactivation of endogenous p53 protein in cancer cells will be therapeutically beneficial, but few tests of this hypothesis have been carried out in vivo. We report that a transducible D-isomer RI-TATp53C' peptide activates the p53 protein in cancer cells, but not normal cells. RI-TATp53C' peptide treatment of preclinical terminal peritoneal carcinomatosis and peritoneal lymphoma models results in significant increases in lifespan (greater than 6-fold) and the generation of disease-free animals. These proof-of-concept observations show that specific activation of endogenous p53 activity by a macromolecular agent is therapeutically effective in preclinical models of terminal human malignancy. Our results suggest that TAT-mediated transduction may be a useful strategy for the therapeutic delivery of large tumor suppressor molecules to malignant cells in vivo.
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PMID:Treatment of terminal peritoneal carcinomatosis by a transducible p53-activating peptide. 1496 35

Many conventional anticancer treatments kill cells irrespective of whether they are normal or cancerous, so patients suffer from adverse side effects due to the loss of healthy cells. Anticancer insights derived from cell cycle research has given birth to the idea of cell cycle G2 checkpoint abrogation as a cancer cell specific therapy, based on the discovery that many cancer cells have a defective G1 checkpoint resulting in a dependence on the G2 checkpoint during cell replication. Damaged DNA in humans is detected by sensor proteins (such as hHUS1, hRAD1, hRAD9, hRAD17, and hRAD26) that transmit a signal via ATR to CHK1, or by another sensor complex (that may include gammaH2AX, 53BP1, BRCA1, NBS1, hMRE11, and hRAD50), the signal of which is relayed by ATM to CHK2. Most of the damage signals originated by the sensor complexes for the G2 checkpoint are conducted to CDC25C, the activity of which is modulated by 14-3-3. There are also less extensively explored pathways involving p53, p38, PCNA, HDAC, PP2A, PLK1, WEE1, CDC25B, and CDC25A. This review will examine the available inhibitors of CHK1 (Staurosporin, UCN-01, Go6976, SB-218078, ICP-1, and CEP-3891), both CHK1 and CHK2 (TAT-S216A and debromohymenialdisine), CHK2 (CEP-6367), WEE1 (PD0166285), and PP2A (okadaic acid and fostriecin), as well as the unknown checkpoint inhibitors 13-hydroxy-15-ozoapathin and the isogranulatimides. Among these targets, CHK1 seems to be the most suitable target for therapeutic G2 abrogation to date, although an unexplored target such as 14-3-3 or the strategy of targeting multiple proteins at once may be of interest in the future.
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PMID:G2 checkpoint abrogators as anticancer drugs. 1507 95

Growth inhibition by transforming growth factor (TGF)-beta 1 has been attributed to the induction of cyclin-dependent kinase inhibitors, among which p21/Waf1 plays a major role in many biological contexts. In the present study, two new intracellular mediators for the induction of p21/Waf1 by TGF-beta 1 were identified in a human hepatocellular carcinoma cell line (JHH-5) expressing mutant-type p53. After addition of TGF-beta 1 to JHH-5 cells, a marked increase of the p21/Waf1 expression preceded the inhibition of DNA synthesis. Expression of IFN regulatory factor (IRF)-1, a known transacting factor for p21/Waf1 promoter, was elevated just before or in parallel with the increase of p21/Waf1. Transduction of antisense IRF-1 inhibited the increase in p21/Waf1 in JHH-5 cells treated with TGF-beta 1 and partially released the cells from the growth arrest by TGF-beta 1. Expression of S100C/A11, a member of the Ca(2+)-binding S100 protein family, also markedly increased after addition of TGF-beta 1. S100C/A11 protein was translocated to and accumulated in nuclei of TGF-beta 1-treated JHH-5 cells, where p21/Waf1 was concomitantly accumulated. When a recombinant S100C/A11 protein was introduced into nuclei of JHH-5 cells, DNA synthesis was markedly inhibited in a dose-dependent manner in the absence of TGF-beta 1. Prior transfection of p21/Waf1-targeted small interfering RNA efficiently blocked decrease of DNA synthesis in JHH-5 cells caused by TAT-S100C/A11 or TGF-beta 1 and markedly inhibited expression of p21/Waf1 protein in the cells. These results indicate that IRF-1 and S100C/A11 mediate growth inhibition by TGF-beta 1 via induction of p21/Waf1.
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PMID:Involvement of interferon regulatory factor 1 and S100C/A11 in growth inhibition by transforming growth factor beta 1 in human hepatocellular carcinoma cells. 1520 26

S100 proteins belong to the EF-hand Ca2+-binding protein family and are involved in the regulation of a variety of cellular processes. Individual S100 proteins are expressed in cell- and tissue-specific manners, and functional deterioration of S100 proteins leads to a number of human diseases, including cancer. We previously demonstrated that S100C/A11 was translocated to nuclei and inhibited DNA synthesis in human keratinocytes when exposed to high Ca2+. In the present study we examined the effects of synthetic partial peptides of S100C/A11 on human carcinoma cell lines. Only an N-terminal peptide with 19 amino acid residues (MAK19) showed cytotoxicity to the cell lines in dose- and time-dependent manners when introduced into cells by flanking the HIV-TAT protein transduction domain (TAT-MAK19). Pulse field electrophoresis revealed that DNA of the treated cells was partially degradated. Annexin V, a marker of cellular apoptosis, was detected in the cells treated with TAT-MAK19 by immunostaining and flow cytometry. The induction of apoptotic cell death was apparently independent of p53, p21WAF1/CIP1, and caspase activity, but treatment with TAT-MAK19 resulted in partial translocation of apoptosis-inducing factor (AIF) from the cytoplasm to nuclei. These results indicate that MAK19 induces apoptosis in human cell lines and may therefore lead to the establishment of a new molecular target for the treatment of human cancer.
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PMID:Introduction of an N-terminal peptide of S100C/A11 into human cells induces apoptotic cell death. 1524

The protein transduction system has been employed for delivery of bioactive proteins into cells via an endocytotic mechanism. However, trapping of endocytosed proteins in the endosome may significantly attenuate biological actions in cells. The present investigation demonstrated that endosomal release of transduced protein could be artificially accelerated by exposure to fluorescent light. Exposure to light at 480 nm stimulated endosomal release of transduced FITC-11 arginine-protein transduction domain (11R-PTD), TAT-PTD and Antennapedia-PTD. Moreover, FITC-11R-p53 protein was released from endosomes following stimulation with light. These data suggest that photo-acceleration is a more efficient strategy in terms of the protein transduction system.
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PMID:Photo-acceleration of protein release from endosome in the protein transduction system. 1530 52


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