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Biomedical subjects

K S Gu

Publications and source records attributed to K S Gu.

2 recordsLinked to original sources

Multidrug resistance in leukemic cell line K562/A02 induced by doxorubicin.

AIM: To study the mechanism of the development of multidrug resistance in leukemic cells. METHODS: A human leukemic cell line K562/A02 was established by stepwise increase of concentrations of doxorubicin (Dox) in medium. P-glycoprotein was detected by immunohistochemistry assay. The mdr1 gene expression was measured by RT-PCR. The amplification of mdr1 gene in its genome, and DNA topisomerase II (Top II) gene expression were determined by dot-blot hybridization. RESULTS: K562/A02 was highly cross-resistant to vincristine (VCR), homoharringtonin (HHT), amsacrine (m-AMSA), daunorubicin (Dau) and etoposide (VP-16), slightly to cytosine arabinoside (Ara-C), but not cisplatin (Cis), methotrexate (MTX) and fluorouracil (5-FU), showing a typical phenotype of MDR. Intracellular accumulation of Dau in K562/A02 was 33% as high as that in K562. P-glycoprotein P-170 was positive. In K562/A02, the mdr1 gene did not amplify, the mdr1 mRNA level was markedly higher, the Top II mRNA level was lower, and glutathione-S-transferase (GST) activity was higher than in K562. CONCLUSION: mdr1 mRNA was overexpression and thus the encoded P-170 was responsible for MDR in K562/A02 while Top II or GST may play a role in MDR.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[Multiple primary lung cancer].

From November 1957 to June 1984, 30 patients with multiple primary lung cancer were diagnosed, basing on clinical features, diagnostic means, histologic type, treatment and prognosis. Out of 3,815 cases of resected primary lung cancer, the incidence of multiple primary cancer was 0.8%. There were 10 synchronous and 20 metachronous cases. There were 17 unilateral, only 1 simultaneous bilateral and 12 contralateral after resection of cancer in the opposite lung. Four of the 10 synchronous cases were definitely diagnosed preoperatively. Among the 20 metachronous cases, 9 were definitely diagnosed as a second primary lesion and the other 11 were proved by thoracotomy. Pathologically, 19 had identical types (15 squamous cell and 4 adenocarcinoma) but 11 had double types (9 squamous cell + adenocarcinoma, 2 squamous cell + anaplastic). The average survival of these 30 patients was 27.1 months, that in the synchronous group was 29 months and that in the metachronous group was 26.2 months. The 5 year survival rate of the synchronous cases was 35%, that of the metachronous cases was 42%. The clinicopathological criteria of multiple primary lung cancer, early diagnostic and operative procedure are also discussed.

Adenocarcinoma↗