Thymidine Phosphorylase (dThdPase) is the rate-tissues expressed high levels of DPD (median >70 U/mg limiting enzyme that metabolizes 5'-deoxy-5-fluorouridine protein), while high concentrations of the dThdPase were (5'-dFUrd, doxifluridine), an intermediate metabolite of expressed in esophageal, cervical, breast, and pancreatic capecitabine, to the active drug 5-fluorouracil (5-FUra), while cancers and hepatoma (median >150 U/mg protein). The dihydropyrimidine dehydrogenase (DPD) catabolizes 5-FUra dThdPase/DPD ratio, which was reported to correlate with to an inactive molecule. The susceptibility of tumors to the susceptibility of human cancer xenografts to capecitabine, fluoropyrimidines is reported to correlate with tumor levels was high in esophageal, renal, breast, colorectal, and gastric of these enzymes. To obtain some insight into the tumor cancers (median ratio of > 1.5). In any of these three parameters, types susceptible to fluoropyrimidine therapy, we measured the inter-patient DPD variability for each cancer type was expression levels of these two enzymes in various types of much larger than the DPD variability among cancer types; human cancer tissues (241 tissue samples) by the ELISA highest/lowest ratios for dThdPase, DPD, and dThdPase/DPD methods. DPD exists in all the cancer types studied, such were 10-321, 7-513, and 2-293, respectively. These results as bladder, breast, cervical, colorectal, esophageal, gastric, indicate that measurements of the three parameters, DPD, hepatic, pancreatic, prostate, and renal cancers. Among them, dThdPase and dThdPase/DPD, would be useful criteria for the cervical, hepatic, pancreatic, esophageal, and breast cancer selecting cancer patients suitable for fluoropyrimidine therapy rather than for selecting cancer types.

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In this study, to better understand the mechanism of oral squamous cell carcinoma (SCC) carcinogenesis, alterations of the p53 gene and overexpression of MDM2 and p53 were analyzed in 38 oral SCC samples. Twelve of the 38 specimens revealed mutant-type p53. Moreover, coexpression of MDM2 and p53 was found most frequently in dysplastic lesions (P < < < <0.05). Expression of MDM2 and p53 was significantly increased in accordance with the histological progression of multistep carcinogenesis (P < < < <0.05). No significant correlation was found between the expression of MDM2 and the alteration of p53 protein or p53 gene status. MDM2 overexpression with mutant p53 was significantly associated with poorly differentiated SCCs (P < < < <0.05) and tumor stages III and IV of oral SCCs (P < < < <0.05). These results suggest that MDM2 overexpression is an early event in oral carcinogenesis through the functional inactivation of the wild-type p53, and corresponding alterations of MDM2 and p53 contribute to the oral carcinogenesis. We propose that it would be clinically more instructive to evaluate MDM2 overexpression combined with p53 gene status, compared to the evaluation of either MDM2 or p53 alteration alone. Key words: MDM2 -p53 -Oral carcinogenesisOral squamous cell carcinoma (SCC) is the most common malignant tumor in the oral cavity.1) Nevertheless, the mechanism of oral carcinogenesis is still poorly understood.2) Previous studies have shown that inactivation of wild-type p53 function by mutation or interaction with a viral oncogene product plays an important role in carcinogenesis, including oral SCC.3-6) However, there are still oral SCCs which do not contain mutant p53 or viral protein. Therefore, it is reasonable to assume the presence of a p53-independent oral carcinogenesis pathway.It was found that MDM2, a cellular oncogene product, can bind to the p53 N-terminal acidic domain to inactivate its transcription factor activity.7, 8) Also, p53 can bind to the first intron of the MDM2 gene to activate MDM2 transcription, thus establishing a negative feedback loop 9) to control the cell cycle.MDM2 can inhibit wild-type p53-mediated G1 arrest and apoptosis.10, 11) MDM2 also plays a role in promoting the S phase in the p53-independent pathway.12) It has been reported that overexpressions of both p53 and MDM2 are more frequent in high-grade bladder cancer.13) MDM2 overexpression is observed in various tumors with or without p53 mutation.14-17) However, the significance of the correlation between the overexpression of MDM2 and the p53 status in the multistep processes of oral SCC development has not yet been clearly elucidated. 18)In this study, to reach a better understanding of the mechanism of oral carcinogenesis, the alterations of the p53 gene in oral SCC specimens were investigated. Furthermore, using the same specimens, the overexpression of MDM2 and p53 was analyzed in normal mucosa adjacent to the tumor, and in premalignant and malignant lesions. MATERIALS AND METHODS MaterialsThe 38 oral SCC specimens used in...

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We have studied the electronic and vibrational properties of CdS and Se clusters in zeolites by Raman scattering and photoluminescence measurements. CdS clusters were formed photochemically through the dissociation of S 8 molecules in A and X types of Cd 2+-exchanged zeolites by laser irradiation, while CdSe clusters were not successfully produced in the same manner. The 1LO mode of CdS at 300 cm −1 shifts to lower frequencies in the zeolites in comparison with that of bulk CdS , indicating the effect of phonon confinement. Se clusters incorporated into zeolites with different pore sizes (3A, 4A, 5A, and 13X) exhibit strong dependence of the structural phase stability and the structural unit on the geometrical constraints of zeolites.