title: Chemotherapy influences inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) activity on 3D breast cancer cell line.
abstract: Multicellular tumor spheroids (MTS) are three-dimensional structural forms of tumors grown in vitro in the laboratory. In this study, the aim was to determine the regulation of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) expressions on MTS in response to treatment with the commonly used anti-cancer drugs Doxorubicin and Docetaxel. The spheroids were generated using the "liquid overlay" technique. The distribution of both iNOS and eNOS was detected using indirect immunohistochemistry, while the expression of both iNOS and eNOS was measured using Western blots. Additionally, S-phase analysis using 5-bromo-2'-deoxyuridine (BrdU) was done on the MTS after treatment with doxorubicin, docetaxel, and a combination of the two. The Griess method was used to measure nitric oxide (NO) production in the cells. An increase in iNOS immunoreactivity and a decrease in eNOS immunoreactivity were observed after doxorubicin treatment, when compared with the other groups. Furthermore, upregulation of iNOS and downregulation of eNOS were detected in doxorubicin-treated cells using Western blotting. Insignificant iNOS expression was observed in all of the groups, and it was particularly low in the control and drug combination groups. NO production was also found to be significantly high after docetaxel treatment, and cell proliferation decreased after doxorubicin treatment. In conclusion, chemotherapy influences NOS activity differently with the presence of different drugs. The results with iNOS show that doxorubicin is a more effective drug than docetaxel, and a drug combination may play a helpful role in the suppression of tumorigenicity and cancer metastasis. Interestingly, eNOS expression increased after the addition of both docetaxel and the drug combination, and it was found to negatively correlate with the histological grade of the tumor. Therefore, analyzing the expression of both iNOS and eNOS might be very useful for targeting the treatment of breast carcinoma and obtaining better information on prognosis.
authors.affiliation: Department of Histology and Embryology, Ege University School of Medicine, TR-35100 Izmir, Turkey. goktem@med.ege.edu.tr
authors.forename: G
authors.initials: G
authors.lastname: Oktem
authors.forename: A
authors.initials: A
authors.lastname: Bilir
authors.forename: N
authors.initials: N
authors.lastname: Selvi
authors.forename: M E
authors.initials: ME
authors.lastname: Yurtseven
authors.forename: S
authors.initials: S
authors.lastname: Vatansever
authors.forename: U
authors.initials: U
authors.lastname: Ates
authors.forename: A
authors.initials: A
authors.lastname: Uysal
authors.forename: S B
authors.initials: SB
authors.lastname: Omay
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology*; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D000077143:Docetaxel; D004317:Doxorubicin / Q000494:pharmacology*; D006801:Humans; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000096:biosynthesis / Q000378:metabolism*; D018874:Spheroids, Cellular; D043823:Taxoids / Q000494:pharmacology*
chemical_list: D000903:Antibiotics, Antineoplastic; D000972:Antineoplastic Agents, Phytogenic; D043823:Taxoids; D000077143:Docetaxel; D009569:Nitric Oxide; D004317:Doxorubicin; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III