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M Musso

Publications and source records attributed to M Musso.

93 records · Page 6Linked to original sources

Effects of R-enantiomer (GR66234A) and L-enantiomer (GR66235A) of telupidine, a new dihydropyridine derivative, on cell lines displaying the multidrug resistant phenotype.

BACKGROUND: Many dihydropyridine analogues with calcium channel blocker activity are able to reverse multidrug resistance (MDR). We studied the daunorubicin resistance reversing activity of the R enantiomer (GR66234A) and the L-enantiomer (GR66235 A) of teludipine, a new lipophilic calcium channel blocker synthesized by Glaxo. METHODS: The daunorubicin resistance reversing activity of the enantiomers of teludipine was evaluated in two MDR cell lines: ARNII, an erythroleukemia cell line which expresses p-glycoprotein, and MCF 7/R, a breast cancer cell line with p-glycoprotein and high levels of glutathione S transferase (GST) and glutathione peroxidase (GSH Px). RESULTS: GR66234A and GR66235A show the same activity in reversing daunorubicin resistance and are more effective than verapamil. The difference in activity between verapamil and the enantiomers of teludipine is greater in ARNII cells than in MCF 7/R cells. Nevertheless, there are no significative differences in cellular daunorubicin accumulation between ARNII and MCF 7/R following exposure to teludipine, nor are there differences in intracellular daunorubicin distribution in the presence of either MDR reversing agent. CONCLUSIONS: The low calcium channel antagonistic activity of GR66234A suggests that this compound may be useful in combination with chemotherapy in MDR malignancies.

Animals↗

Low-dose long-term oral idarubicin in maintenance treatment of elderly acute myeloid leukemia.

BACKGROUND AND OBJECTIVE: Low-dose long-term oral IDA may play a role in maintainance treatment of elderly patients with AML; in fact, continuous exposure to IDA and IDAol could be efficacious in the disease control possibly inducing cell-differentiation and/or apoptosis. METHODS: We enrolled 25 previous responder patients in standard induction therapy to receive maintenance oral IDA 5 mg daily on days 1-14 at 2-week intervals for at least 6 months. We also evaluated the cell-cycle and apoptosis in leukemic cells from patients after IDA administration and, as a control, from HL60 lines exposed to IDA and IDAol in vitro. RESULTS: Long-term long-dose IDA was well-tolerated. Neutrophil and platelet count never below under 1 x 10(9)/L and 50 x 10(9)/L respectively in CR patients, and no infectious complications were encountered. Non-hematological toxicity was also acceptable: easily controlled nausea and vomiting, non-recorded diarrhea or mucositis were reported. The convenience of oral administration contributed to excellent compliance. DNA analysis performed in vivo after IDA and IDAol exposure showed an increase of G2/M cell frequencies and evidence of sub-G1 peak. INTERPRETATION AND CONCLUSIONS: In conclusion, long-term low doses of oral IDA would appear valuable as a maintenance regimen for elderly patients. Our results seem to confirm the preliminary hypothesis that IDA + IDAol induce an increase of apoptosis in leukemic cells.

Acute Disease↗