Effect of paclitaxel on intracellular localization of c-Myc and P-c-Myc in prostate carcinoma cell lines.
The proto-oncogene c-myc is involved in multiple cell pathways with opposite effects on cell outcome of death or proliferation. It has been proposed that these different roles depend on the sequestration of c-Myc protein in cellular compartments and/or its phosphorylation. We speculated that subcellular localization of c-Myc protein and of its phosphorylated form (P-c-Myc) could have a role in the different response to paclitaxel (PTX) in two prostate carcinoma cell lines, PC3 and DU145, which undergo either multinucleation or c-myc-dependent apoptosis, respectively. c-myc is amplified only in PC3, but a similar extent of c-Myc phosphorylation was observed in both cell lines after PTX treatment. We found that PTX-induced upregulation of c-myc in DU145 cells, not occurring in PC3 cells, cannot be ascribed to a different protein localization, and that a comparable c-Myc and P-c-Myc nuclear translocation occurs in both cell lines after drug treatment. Thus, subcellular localization of c-Myc and P-c-Myc is not crucial in determining the mode of cell death in these prostate carcinoma cell lines.
Supino
Rosanna
R
Istituto Nazionale Tumori, Via Venezian 1, 20133 Milano, Italy. rosanna.supino@istitutotumori.mi.it
Favini
Enrica
E
Cuccuru
Giuditta
G
Zunino
Franco
F
Scovassi
A Ivana
AI
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002277:Carcinoma / Q000188:drug therapy* / Q000378:metabolism; D045744:Cell Line, Tumor; D006801:Humans; D007424:Intracellular Fluid / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D017239:Paclitaxel / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*
D000972:Antineoplastic Agents, Phytogenic; C000715470:MAS1 protein, human; C489427:MYC protein, human; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc; D017239:Paclitaxel