calcimycin and Ovarian-Neoplasms

Although patients with gynecological malignancies now survive longer due to advances in early diagnosis and therapy, major issues still remain regarding the quality of life for the survivors. Surgical menopause increases the risk of atherosclerosis; however, few studies have investigated the influence of platinum-based adjuvant chemotherapy. This study was conducted to evaluate the effects of platinum-based chemotherapy on atherosclerosis.. This study enrolled 47 women (26 with ovarian cancers and 21 with endometrial cancers) who underwent surgical treatment, with or without platinum-based adjuvant chemotherapy, according to established protocols between 2007 and 2009. Arterial stiffness was measured by brachial-ankle pulse wave velocity (baPWV) performed before surgery, and subsequently at 12 months after treatment. The flow-mediated dilatation of the brachial artery was measured before and immediately following chemotherapy to evaluate the vascular endothelial damage. Human umbilical vein endothelial cells (HUVECs) were used to evaluate cisplatin-induced vascular endothelial dysfunction in vitro.. Although there were no significant differences in the baPWV associated with surgical treatment, platinum-based chemotherapy was associated with an increased baPWV. Significant decreases of flow-mediated dilatation were observed immediately following chemotherapy. An in vitro examination demonstrated that cisplatin attenuated nitric oxide production via inhibition of Akt-eNOS cascades in HUVECs.. This research suggests that platinum-based chemotherapy directly induces vascular endothelial dysfunction and may be a risk factor for the development of atherosclerosis. Therefore, gynecologic cancer survivors should be educated about these potential risks, and informed regarding lifestyle modifications that may benefit their general health.

Topics: Ankle Brachial Index; Antineoplastic Agents; Atherosclerosis; Blood Flow Velocity; Brachial Artery; Calcimycin; Carboplatin; Cells, Cultured; Chemotherapy, Adjuvant; Cisplatin; Endometrial Neoplasms; Endothelial Cells; Endothelium, Vascular; Female; Humans; Ionophores; Middle Aged; Nitric Oxide Synthase Type III; Oncogene Protein v-akt; Ovarian Neoplasms; Paclitaxel; Phosphorylation; Triglycerides; Ultrasonography; Umbilical Veins

We compared the sensitivities to apoptosis via anti-Fas antibody of two human ovarian cancer cell lines, NOS4 and SKOV-3, both of which strongly express the Fas antigen on their cell surface. Treatment with anti-Fas antibody induced extensive DNA fragmentation in NOS4 cells but none in SKOV-3 cells. However; both cell lines underwent apoptosis in response to calcium ionophore A23187 or sphingomyelinase, demonstrating that the latter cell line is capable of DNA fragmentation. DNA fragmentation was not induced in either cell line by treatment with PKC activator PMA, however treatment with protein kinase C (PKC) inhibitor H-7 induced extensive DNA fragmentation in NOS4 cells, but again none in SKOV-3 cells. Protein kinase A inhibitor HA1004 treatment did not induce DNA fragmentation in either cell line. Correspondingly, treatment of cells with PMA before anti-Fas antibody or A23187 treatment partially inhibited induction of DNA fragmentation in NOS4 cells but not in SKOV-3 cells. Both NOS4 and SKOV-3 cell lines expressed isozymes of PKC at comparable levels. These results suggest the presence of a PKC-dependent anti-apoptotic mechanism in association with high sensitivity to anti-Fas antibody in these ovarian cancer cell lines.

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Antibodies; Apoptosis; Calcimycin; Cell Division; Ceramides; Cyclic AMP-Dependent Protein Kinases; DNA Fragmentation; Enzyme Inhibitors; fas Receptor; Female; Flow Cytometry; Humans; Isoquinolines; Ovarian Neoplasms; Protein Kinase C; Signal Transduction; Sphingomyelin Phosphodiesterase; Sulfonamides; Tetradecanoylphorbol Acetate; Tetrazolium Salts; Thiazoles; Tumor Cells, Cultured

The breast and ovarian cancer susceptibility gene BRCA1, is a nuclear phosphoprotein which functions as a tumor suppressor. To investigate the role of BRCA1 in apoptosis, we have developed mouse fibroblast cell lines and human breast cancer cell lines expressing BRCA1. The expression of BRCA1 protein in the BRCA1 transfectants were analysed by immunofluorescence and immunohistochemistry. The BRCA1 transfectants showed a flattened morphology compared to the parental cells. We show that serum deprivation or calcium ionophore treatment of BRCA1 transfectants resulted in programmed cell death. These results indicate that BRCA1 genes may play a critical role in the regulation of apoptosis. Thus, since a wide variety of human malignancies like breast and ovarian cancers have a decreased ability to undergo apoptosis, this could be due to lack/decreased levels of functional BRCA1 proteins. Treatments that are aimed at increasing the apoptotic threshold by BRCA1 gene therapy may have the potential to prevent the progression of these malignancies.

Topics: 3T3 Cells; Animals; Apoptosis; BRCA1 Protein; Breast Neoplasms; Calcimycin; Cell Line; DNA, Complementary; Female; Fibroblasts; Genes, Tumor Suppressor; Humans; Ionophores; Mice; Neoplasm Proteins; Ovarian Neoplasms; Recombinant Fusion Proteins; Transcription Factors; Transfection; Tumor Cells, Cultured

The present study aimed to investigate the role of protein kinase C (PKC), the phosphatidylinositol pathway (PI) and cytosolic calcium in multidrug resistance (MDR) in human ovarian carcinoma cells. Binding of the phorbol ester 13,14-dibutyrate (PDBu) was 3-fold higher in resistant A2780AD versus sensitive A2780 cells indicating increased PKC activity. However, when inositol phosphate production (IP) was measured in quiescent cells similar total IP release was seen in both lines suggesting no difference in the basal turnover of PI. Non-specific stimulation of the PI pathway was achieved with the calcium ionophore A23187 which increased IP production in a time- and dose-dependent fashion in both cell lines but was significantly less effective in A2780AD. The PI pathway was investigated further using the agonists aluminium fluoride, serum and bombesin but these agents failed to elicit a response. The effect of a wide range of Adriamycin concentrations on the PI cycle and cell growth was also studied. Intracellular calcium was measured with the fluorescent dye fura-2-pentaacetoxymethylester (Fura-2). A23187 produced a rise in cytosolic calcium in A2780 and A2780AD but from a level 3-fold lower in the unstimulated resistant cell line. The dose responsiveness of this effect was greater but irreversible in A2780AD cells. Collectively these results imply that alterations in PI turnover appear not to be responsible for the differences in PDBu binding and calcium handling observed between A2780 and A2780AD and suggests only a minor role for the PI cycle in the maintenance of MDR in human ovarian cancer cell lines.

Topics: Calcimycin; Calcium; Cell Line; Dose-Response Relationship, Drug; Doxorubicin; Drug Resistance; Female; Humans; Inositol Phosphates; Models, Biological; Ovarian Neoplasms; Phorbol Esters; Phosphatidylinositols; Protein Kinase C

The induction of glucose-regulated proteins by a variety of specific inducers leads to an increase in resistance to Adriamycin (Shen et al., Proc. Natl., Acad. Sci. USA, 84: 3278, 1987). In this study we examine several additional agents for cross-resistance induced during a glucose-regulated response in an attempt to better define the mechanism through which this phenomenon occurs. When anoxia, calcium ionophore A23187, or 2-deoxyglucose are used, a substantial resistance is obtained against the topoisomerase II-targeted agent, etoposide. Partial resistance is induced against vincristine and actinomycin D. Glucose-regulated protein inducers do not substantially alter cellular response to either bleomycin or radiation. In the case of mitomycin C there is a cellular sensitization with anoxia and 2-deoxyglucose while calcium ionophore A23187 had no effect on survival. This study suggests that the resistance obtained during a glucose-regulated response against etoposide and Adriamycin may involve topoisomerase II.

Topics: Animals; Calcimycin; Cricetinae; Cricetulus; Dactinomycin; Deoxyglucose; Doxorubicin; Drug Resistance; Etoposide; Female; HSP70 Heat-Shock Proteins; Hypoxia; Membrane Proteins; Ovarian Neoplasms; Tumor Cells, Cultured; Vincristine