Karaca B.Degirmenci M.Ozveren A.Atmaca H.Bozkurt E.Karabulut B.Sanli U.A.Uslu R.2024-07-222024-07-22201503445704http://akademikarsiv.cbu.edu.tr:4000/handle/123456789/16303Purpose: Docetaxel (DTX) is widely used for the treatment of metastatic prostate and breast cancers. Despite the clinical success of DTX, drug-related cumulative toxicity restricts its clinical use in cancer therapy. Thus, there is an urgent need for new therapeutic options. Octreotide (OCT) is a synthetic somatostatin analog that induces apoptosis in different cancer cell lines in vitro. In this study, we investigated the possible synergistic apoptotic effects of DTX in combination with OCT in prostate and breast cancer cell lines. Methods: The XTT cell viability assay was used to determine cytotoxicity. Apoptosis was evaluated by Cell Death Detection ELISAPlus Kit. The expression levels of apoptotic proteins were assessed by human apoptosis antibody array. Levels of SSTR2 and SSTR5 proteins were determined by western blot analysis. Results: DTX and OCT combination induced apoptosis in both breast and prostate cancer cells in a concentration- and time-dependent manner. Moreover, combination treatment resulted in inhibition of anti-apoptotic proteins such as Bcl-2 and Bcl-xL and induction of pro-apoptotic proteins Bax, Cytochrome c and IAPs in all of the tested cancer cell lines. SSTR2 and SSTR5 protein levels were induced as compared to any agent alone. Conclusions: These results indicate that this combination treatment is a significant inducer of apoptosis in a synergistic manner in breast and prostate cancer cells. This strong synergism helps to lower the dose of DTX in both types of cancers, thus letting DTX to be used for longer periods by delaying resistance development and lesser side effects. © 2015 Springer-Verlag Berlin Heidelberg.EnglishAntineoplastic Combined Chemotherapy ProtocolsApoptosisApoptosis Regulatory Proteinsbcl-2-Associated X Proteinbcl-X ProteinBreast NeoplasmsCell Line, TumorCell SurvivalCytochromes cDrug SynergismFemaleHumansInhibitor of Apoptosis ProteinsMaleOctreotideProstatic NeoplasmsProto-Oncogene Proteins c-bcl-2Receptors, SomatostatinTaxoidscytochrome cdocetaxeloctreotideprotein Baxprotein bcl 2protein bcl xlsomatostatin receptor 2somatostatin receptor 5antineoplastic agentapoptosis regulatory proteinBAX protein, humanBCL2L1 protein, humancytochrome cdocetaxelinhibitor of apoptosis proteinoctreotideprotein Baxprotein bcl 2protein bcl xsomatostatin receptorsomatostatin receptor 5somatostatin receptor subtype 2, humantaxoidapoptosisArticlebreast cancer cell linecell deathcell proliferationcell viability assaycontrolled studycytotoxicityDNA fragmentationenzyme linked immunosorbent assayhumanhuman cellmalepriority journalprostate cancer cell lineprotein expressionapoptosisBreast Neoplasmscell survivaldrug effectsdrug potentiationfemalegeneticsProstatic Neoplasmstumor cell lineDocetaxel in combination with octreotide shows synergistic apoptotic effect by increasing SSTR2 and SSTR5 expression levels in prostate and breast cancer cell linesArticle10.1007/s00280-015-2756-1