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Biomedical subjects

A R Zhou

Publications and source records attributed to A R Zhou.

17 recordsLinked to original sources

Introduction of wild-type p53 gene downregulates the expression of H-ras gene and suppresses the growth of bladder cancer cells.

Retroviral vectors were used to introduce the wild-type p53 gene into human bladder cancer cell lines BIU-87 and EJ, which express endogenous wt-p53 gene and have a mutation in H-ras gene. The expression of the exogenous wt-p53 gene in cells suppresses the growth of the bladder cancer cells in standard culture and in soft agar and blocks the cell cycle progression in G1. The BIU-87 and EJ cells developed tumors with average volumes of 6.53 cm3 and 6.61 cm3 in nude mice in 9 weeks after inoculation, while the cells transduced with wt-p53 gene failed to form tumors. The expression of H-ras gene in bladder cancer cells was reduced at mRNA level. These results suggest that the overexpression of the wt-p53 gene suppresses the expression of mutant H-ras gene and inhibits the tumor cell growth in vivo and in vitro.

Animals↗

[Study on hsp 70 gene level in cultured smooth muscle cells and aorta from SHR and WKY rats].

Using nucleic hybridization, we investigated hsp 70 gene level on: 1. aorta on spontaneous hypertension rats (SHR); 2. cultured SHR and WKY smooth muscle cells (SMCs) induced by heat shock; 3. cultured SHR and WKY SMCs in 6 weeks and 3 months. The results indicated that hsp 70 mRNA increased in aorta of SHR (6 weeks), in cultured SHR SMCs as compared with WKY SMCs induced by heat shock (42 degrees C, 15 minutes), and in cultured SHR SMCs (6 weeks) as compared with WKY SMCs (6 weeks). Meanwhile, hsp 70 mRNA of cultured SHR SMCs in 6 weeks was higher than that in 3 months. We postulated that overexpression of hsp 70 of cultured SMCs and aorta of SHR in 6 weeks might be related with cellular proliferation during the development of hypertension and that the cultured SHR SMCs might be sensitive to heat shock.

Animals↗

[Relation of HSP70 gene and spontaneously hypertension in rats].

The level of heat shock protein 70 messenger RNA was examined in aortic smooth muscle cells (ASMC) and hepatic tissue of Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). The restriction fragment length polymorphism (RFLP) was also analysed in hepatic DNA. It was demonstrated that the basic level of heat shock protein 70 messenger RNA in ASMC and hepatic tissue of SHR were lower than that of the WKY rats. The extent of heat shock protein 70 messenger RNA accumulated in ASMC was higher in SHR than in WKY rats when the cells were heated by immersing the culture bottles in 42 degrees C water bath for 15 min and allowed to recover at 37 degrees C for 2 h. In contrast with WKY rats, the Bam HI restricted bepatic DNA showed that a fragment about 5.6 kb was lost in heat shock protein 70 gene from hepatic DNA of SHR. The results suggest that the ASMC of SHR is more sensitive to heat stress than that of WKY rats and the changes of heat shock protein gene sequence may be related to genetic hypertension.

Animals↗

[Transcription of HSP 70 gene induced by pressure overload in left ventricule of rats].

The changes of heat shock protein 70 (HSP70) messenger RNA was examined in rats after abdominal aortic partial ligation. Four hours after ligation, the systemic arterial pressure was increased and thereafter maintained at a high level. The ratio of left ventricule weight to body weight began to increase at the third day and increased by 59%, comparing with that of the sham-operated rats at 4 w. Accumulation of HSP 70 mRNA was observed at 4 h and maintained at high level at 1 d, 2 d, 1 w and then gradually disappeared there after. The above experimental results suggest that transcription of HSP 70 gene was induced at an early stage of cardiac hypertrophy caused by pressure overload.

Animals↗

The physico-chemical properties of cancer-suppressive factor.

Biological fluids of mammalia possess a cancer-suppressive activity. CSF has been isolated from ascitic fluid (Ehrlich ascites carcinoma) in this laboratory. Chemically, it is a peptide complexing with lipids, and inhibits the cancer cells in vitro, but has a little effect on normal bone marrow cells. This paper reports the molecular homogeneity, amino acid composition, approximate molecular weight and terminal structures of the peptide.

Amino Acid Sequence↗