Resistance to taxanes is induced by c-erbB-2 overexpression in human MCF-10A mammary epithelial cells and is blocked by combined treatment with an antisense oligonucleotide targeting type I protein kinase A.
We have tested the sensitivity of human MCF-10A mammary epithelial cells and of their transformed derivatives overexpressing an activated c-Ha-ras gene (MCF-10A Ha-ras cells), the c-erbB-2 gene (MCF-10A c-erbB-2 cells) or both genes (MCF-10A HE cells) to different cytotoxic drugs. As compared with parental MCF-10A cells, the transformed cells exhibited an increased sensitivity to topoisomerase I- and topoisomerase II-inhibitors, and to platinum-derivatives with a 2- to 10-fold reduction in IC(50) values. A remarkable difference in sensitivity was observed following treatment with taxanes. While MCF-10A Ha-ras cells showed an increased sensitivity, MCF-10A c-erbB-2 and MCF-10A HE cells exhibited a relative resistance to taxol and taxotere, with an approximately 3.5- to 6.5-fold higher IC(50) as compared with MCF-10A cells suggesting that c-erbB-2 overexpression has a dominant effect compared with an activated c-Ha-ras gene. The type I cAMP-dependent protein kinase (PKAI) is overexpressed in cancer cells. Inhibition of PKAI by antisense oligonucleotides targeting its RIalpha regulatory subunit results in cancer cell growth inhibition. To evaluate the effect of blocking PKAI on MCF-10A cell sensitivity to taxanes, we treated these cells with taxol or taxotere in combination with a PKAI antisense oligonucleotide. Treatment with this agent, but not with a control scramble sequence, was able to overcome the effect of c-erbB-2 overexpression on MCF-10A cell sensitivity to taxol and taxotere, with a 20- to 40-fold shift in the IC(50) values for the 2 drugs.
Ciardiello
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Cattedra di Oncologia Medica, Dipartimento di Endocrinologia e Oncologia Molecolare e Clinica, Facoltà di Medicina e Chirurgia, Università degli Studi di Napoli Federico II, Naples, Italy. fortunatociardiello@yahoo.com
Caputo
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Pomatico
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De Laurentiis
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De Placido
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Bianco
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Tortora
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D000970:Antineoplastic Agents / Q000633:toxicity*; D001940:Breast / Q000166:cytology; D001943:Breast Neoplasms; D016190:Carboplatin / Q000633:toxicity; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000633:toxicity; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics*; D000077143:Docetaxel; D004317:Doxorubicin / Q000633:toxicity; D004847:Epithelial Cells / Q000166:cytology; D005047:Etoposide / Q000633:toxicity; D005260:Female; D018734:Genes, erbB-2 / Q000187:drug effects*; D006801:Humans; D020319:Oligodeoxyribonucleotides, Antisense / Q000633:toxicity*; D017239:Paclitaxel / Q000031:analogs & derivatives* / Q000633:toxicity*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics; D043823:Taxoids; D059004:Topoisomerase I Inhibitors; D059005:Topoisomerase II Inhibitors; D019772:Topotecan / Q000633:toxicity; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D016190:Carboplatin; D002945:Cisplatin; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D000077143:Docetaxel; D004317:Doxorubicin; D005047:Etoposide; D020319:Oligodeoxyribonucleotides, Antisense; D017239:Paclitaxel; D018719:Erb-b2 Receptor Tyrosine Kinases; D043823:Taxoids; D059004:Topoisomerase I Inhibitors; D059005:Topoisomerase II Inhibitors; D019772:Topotecan