Purpose: Although single nucleotide polymorphisms (SNP) of the dihydropyrimidine dehydrogenase gene (DPYD) have been reported, which affect enzyme activity and the severity of 5-fluorouracil (5-FU) toxicity, no pretherapeutic detection has thus far been developed. We investigated 22 DPYD gene SNPs, their respective incidence, their link with grade 3 to 4 toxic side effects, and their management in practice: 9 were looked for in 487 patients, whereas 13 others were investigated in 171 patients. Patients and Methods: SNPs were detected before 5-FU-based treatment in WBC using a Pyrosequencing method. Close clinical and biological follow-up was done. Results: Five different SNPs were found in 187 patients (IVS14 + 1G>A, 2846A>T, 1679T>G, 85T>C, −1590T>C). Three hundred patients had no SNP. Forty-four patients had grade 3 to 4 toxic side effects in either the first or second cycle. Sixty percent of patients with either IVS14 + 1G>A or 2846A>T SNPs and the only patient with 1679T>G SNP experienced early grade 3 to 4 toxicity, compared with 0%, 5.5%, and 15% of those with either −1590T>C, 85T>C SNP, or no SNP, respectively. In cases with grade 3 to 4 toxicity, treatment either had to be quickly stopped, or could be safely continued with an individual dose adjustment. Sensitivity, specificity, and positive and negative predictive values of the detection of these three major SNPs as toxicity predictive factors were 0.31, 0.98, and 0.62 and 0.94, respectively. Conclusion: Pretreatment detection of three DPYD SNPs could help to avoid severe toxic side effects. This approach is suitable for clinical practice and should be compared or combined with pharmacologic approaches. In the case of dihydropyrimidine dehydrogenase deficiency, 5-FU administration often can be safely continued with an individual dose adjustment. [Mol Cancer Ther 2006;5(11):2895–904]

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To analyze regulation of the human T-cell leukemia virus type I (HTLV-I) long terminal repeat (LTR), cell lines were generated from LTR-tax x LTR-jI-galactosidase (j-Gal) doubly transgenic mouse fibroblastic tumors. The HTLV-I LTR directs expression of both the tax and lacZ genes, and Tax up-modulates both promoters in primary cells. However, once cells were transformed by tax, I-Gal but not tax expression was suppressed. Supertransformation of these cells with v-src suppressed both ,8-Gal and tax expression. This suppression was reversed by treatment with the tyrosine kinase inhibitor herbimycin A or protein kinase A inhibitor H8. Electrophoretic mobility shift assays demonstrated augmented binding in the R but not U3 region. This binding was competitively inhibited by a high-affinity CREB oligodeoxynucleotide and supershifted with a specific CREB antibody. Treatment of cells with the cyclic AMP analog dibutyryl cyclic AMP also transiently increased the R region binding dramatically. In vitro DNase I footprint analysis identified a protein-binding sequence in the R region which corresponded with suppression. However, this target sequence lacked a conventional CREB-binding site. A 70.5-kDa DNA-binding protein was partially purified by affinity chromatography, along with a 49-kDa protein which reacted with CREB-specific sera. These data demonstrate that HTLV-I LTR suppression is associated with CREB factor binding in the R region, probably by direct interaction with a 70.5-kDa protein, and provide a novel mechanism for maintenance of viral latency.Human T-cell leukemia virus type I (HTLV-I) has been identified as the etiologic agent of adult T-cell leukemia/ lymphoma (reviewed in references 40 and 64). A hallmark of HTLV-I infection is its latency. Adult T-cell leukemia/lymphoma develops after a characteristically long latent period of 20 or more years after initial exposure (40). The proviral genome is readily found in the DNA of primary leukemic lymphocytes (56, 65). However, leukemic cells do not express significant levels of viral antigens unless they are cultured in vitro in the presence of mitogens (16,36). Both methylation and partial deletion of the viral genome have been associated with in vivo latency (55), but the factors that initiate latency are poorly understood.Specific interaction of host cell transcription factors with the U3 portion of the HTLV-I long terminal repeat (LTR) is crucial in regulating viral expression (reviewed in reference 22). The 5' U3 region contains a transcriptional enhancer composed of 21-bp repeat elements (Tax response elements) (18,46,49,54) and sequences homologous to other transcriptional factor-binding motifs such as AP-1 (47, 66), Etsl (11,21), 47), and AP-2 (38). The virus-encoded Tax transactivator recently has been shown to increase the in vitro

To analyze regulation of the human T-cell leukemia virus type I (HTLV-I) long terminal repeat (LTR), cell lines were generated from LTR-tax x LTR-beta-galactosidase (beta-Gal) doubly transgenic mouse fibroblastic tumors. The HTLV-I LTR directs expression of both the tax and lacZ genes, and Tax up-modulates both promoters in primary cells. However, once cells were transformed by tax, beta-Gal but not tax expression was suppressed. Supertransformation of these cells with v-src suppressed both beta-Gal and tax expression. This suppression was reversed by treatment with the tyrosine kinase inhibitor herbimycin A or protein kinase A inhibitor H8. Electrophoretic mobility shift assays demonstrated augmented binding in the R but not U3 region. This binding was competitively inhibited by a high-affinity CREB oligodeoxynucleotide and super-shifted with a specific CREB antibody. Treatment of cells with the cyclic AMP analog dibutyryl cyclic AMP also transiently increased the R region binding dramatically. In vitro DNase I footprint analysis identified a protein-binding sequence in the R region which corresponded with suppression. However, this target sequence lacked a conventional CREB-binding site. A 70.5-kDa DNA-binding protein was partially purified by affinity chromatography, along with a 49-kDa protein which reacted with CREB-specific sera. These data demonstrate that HTLV-I LTR suppression is associated with CREB factor binding in the R region, probably by direct interaction with a 70.5-kDa protein, and provide a novel mechanism for maintenance of viral latency.