Biomedical subjects

Z Han

Publications and source records attributed to Z Han.

148 records · Page 9Linked to original sources

PubMedDate not supplied

Extract from Arca granosa L. inhibits proliferation of human tumour cell lines with kidney and lung origin.

Marine organisms are being considered increasingly as sources of anti-tumour agents. The extract from Arca granosa L. has been shown to decrease the growth of tumours and this study was undertaken to determine its ability and mechanism of inhibition. The extract inhibited the proliferation of six human tumour cell lines from different origins with varying sensitivity. The cell lines Ketr-3, A549 and NCl-H460 with kidney or lung origins were more sensitive to the extract than those of the HepG-2, MCF-7 and MGC-803 cells from other origins. In the three sensitive cell lines (Ketr-3, A549 and NCI-H460) the extract was shown to block different phases of the cell cycle progression and inhibit DNA synthesis in a concentration-dependent manner. It was concluded that the extract from A. granosa is potentially a novel anti-tumour agent, especially on kidney and lung tumour cell lines.

Animals↗

PubMedDate not supplied

Schedule-dependent efficiency of thermochemotherapy in vitro with etoposide and heating at 43 degrees C.

We have investigated the effect of hyperthermia (HT) treatment on the extent of etoposide-induced apoptosis in human leukemia HL-60 cells. The cells were heated at 43 degrees C for 15 to 60 min. Relative quantitative changes in the apoptotic (Ap) fractions were monitored by flow cytometry, HT treatment for 15 min prior to or concurrently with etoposide exposure had no effect on the Ap fraction generated by the drug alone, whereas, 60 min heating resulted in an increase in the Ap fraction. Heating of the cells at 6 to 24 hr after drug exposure enhanced the Ap fraction. Taken collectively, the results indicate that appropriately scheduled HT and etoposide treatments may lead to a thermochemotherapy protocol that will result in increased etoposide-induced death of human leukemia cells.

Antineoplastic Agents, Phytogenic↗

PubMedDate not supplied

9-Nitrocamptothecin is an effective drug for the treatment of human lung tumors: comparison of in vitro and in vivo studies.

9-Nitrocamptothecin (9NC) results in complete regression of small-cell lung carcinoma (SCLC) and non-SCLC (NSCLC) growing as xenografts in immunodeficient mice. In this study, we have monitored histological changes in the tumors during 9NC-induced regression, and perturbations in the cell cycle of cells derived from these tumors using flow cytometry. In vivo, 9NC treatment induces dramatic changes in the tumor cells, which die by apoptosis and are ultimately eliminated from the normal tissue. In vitro, 9NC treatment resulted in apoptosis and cytostasis of the NSCLC and SCLC cells, respectively. Further, 9NC induced cytostasis in control, normal human lung fibroblasts. Therefore, the studies in vivo have indicated that 9NC acquires a remarkable antitumor activity against both the SCLC and NSCLC types tested, and that results of studies in vitro may not reflect the results observed in vivo.

Animals↗

PubMedDate not supplied

Development of human leukemia U-937 cell sublines resistant to doxorubicin: induction of differentiation and altered sensitivities to topoisomerase-directed drugs.

Cell sublines resistant to doxorubicin (DOX) were developed from the human leukemia cell line, U-937/WT, exposed to stepwise DOX increases. In contrast to U-937/WT cells, the DOX-resistant U-937/RD cells have longer doubling time; are more differentiated along the monocytic lineage as determined by the presence of morphological features and mRNA coding for the monocyte colony-stimulating factor-1 receptor; synthesize the apoptosis-associated Bax protein; are less sensitive to apoptosis-inducing topoisomerase II-directed drugs, apparently because of increased synthesis of P-glycoprotein; and are practically non-tumorigenic when xenografted in nude mice. However, U-937/WT and U-937/RD cells exhibit similar sensitivity to the apoptosis-inducing drug 9-nitrocamptothecin. These findings suggest that several mechanisms are involved in the development of DOX-resistance in U-937 cells, and further, 9-nitrocamptothecin can overcome resistance to DOX. These findings may have clinical implications.

ATP Binding Cassette Transporter, Subfamily B, Mem↗