Shaohong Ding

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In order to investigate the relative levels of expression of human cytochrome P-450 (P-450) CYP2A genes and determine how this relates to polymorphism in coumarin hydroxylase activity, cDNA clones for members of the CYP2A gene family were isolated. These clones were CYP2A6, CYP2A7 and an alternatively spliced version of CYP2A7 (CYP2A7AS). The latter clone(More)
Expression of recombinant cytochrome P450s (P450s) in mammalian cells has been used as a powerful tool to study these enzymes. However, the activity of CYP3A4 expressed in several stable mammalian cell lines was much lower than native enzyme in human liver. The low level of recombinant CYP3A4 may have been due to the low copy number of the cDNA. In(More)
A segment of 712 bases coding for part of the human stearoyl-CoA desaturase gene was made by polymerase chain reaction (PCR) using primers based on published rat cDNA sequences. The human PCR product was confirmed by DNA sequencing. It was next cloned into a vector from which anti-sense, highly radioactive RNA transcripts were made in vitro using T7(More)
The multidrug resistant protein MDR-1 has been associated with the resistance to a wide range of anti-cancer drugs. Taxol is a substrate for this transporter system and is used in the treatment of a wide range of human malignancies including lung, breast and ovarian cancer. We have generated a series of ovarian cell lines resistant to this compound, all of(More)
The catalytic activities of recombinant cytochrome P450s expressed in E. coli have been impeded by the absence of endogenous P450 reductase. To solve this problem, we coexpressed P450 reductase with CYP3A4. Membranes from this strain contained 215 pmol P450/mg protein and a reductase activity of 1315 nmol cytochrome c reduced/min per mg. We detected(More)
A pilot study, to assess the therapeutic potential of percutaneous injection of wild-type p53 (wt-p53) in five patients with primary hepatocellular carcinoma is reported. Three of the five patients showed objective tumor response with reduction of the tumor volume on computed tomographic (CT) scan measurements as well as a significant fall of serum(More)
Forty-two patients with hepatocellular carcinoma (HCC) were resected and their tumours were analysed for p53 mutations by GC-clamped denaturing gradient gel electrophoresis (DGGE), single-strand conformation polymorphism (SSCP) and gene sequencing. All the exons have been analysed in this study. Eight of 12 HCCs with cirrhosis due to viral hepatitis and the(More)
Molecular genetic changes are better characterized in colorectal carcinoma than in other common adult tumours. Consistent allele losses, or loss of heterozygosity (LOH), on chromosomes 5q, 17p and 18q have been well established. These changes are associated with the prognosis of the disease. Little is known of such changes in liver metastases of colorectal(More)
A wide variety of pharmacological and toxicological properties of drugs are determined by cytochrome P450-mediated metabolism. Characterization of these pathways and of the P450 isoenzymes involved constitutes an essential part of drug development. Similarly, because P450s are catalyzing the toxication and detoxication of environmental pollutants, an(More)