- Email: [email protected]
Surveillance and health outcomes for BRCA mutation carriers following risk-reducing salpingo-oophorectomy (RRSO)
188
Abstracts / Gynecologic Oncology 139 (2015) 178–207
independent experiments were performed to identify differentially expressed genes from tumors of ovarian serous histology (p ≤ 0.01). These differentially expressed genes were then compared to identify a set of genes that is uniformly overexpressed in both uterine and ovarian serous tumors. Results: This analysis revealed only 3 genes (FBXL5, EYA2, PPP2R2D) to be consistently overexpressed in serous cancers, independent of the site of origin. In contrast, 60 genes were identified to be overexpressed consistently in the endometrioid ovarian and uterine tumors. Conclusion: Patients with ovarian and uterine cancers of serous histology appear to possess a distinct genetic profile with few to no overlapping genes in common. Further analysis into the genetic and molecular profiles of these common and aggressive tumors is warranted, and could open the door to new therapeutic strategies. doi:10.1016/j.ygyno.2015.07.043
BRCAness in endometrial cancer J.M. Stephan, E. Cohen, J. Gonzalez. Bosquet University of Iowa Hospitals and Clinics Objectives: The term BRCAness describes the phenotypic traits that some sporadic ovarian tumors share with tumors in BRCA1/2 germline mutation carriers and reflects similar causative molecular abnormalities. Molecular profiling through The Cancer Genome Atlas database (TCGA) revealed BRCA-related defects in almost half of the cases of ovarian cancer, opening the gate to new therapeutic strategies in these patients. We sought to evaluate the frequency, prognostic significance, and potential clinical application of BRCAness in both serous and endometrioid endometrial cancer. Methods: Mutation data as well as clinical and follow-up information were downloaded from TCGA server. When cancer cells acquire mutations within the homologous recombination (HR) DNA-repair pathway (as happens with BRCA1&2 mutations) we considered them to have a ‘BRCAness phenotype’. Mutations on HR DNA-repair genes from TCGA databases for both ovarian and endometrial cancer were recorded. Kaplan–Meier and Log-rank survivorship were calculated for both clinical and mutation variables of interest for both cancers. Cox proportional hazardratios were computed to identify independent variables associated with survival. Results: 47 patients with serous endometrial cancer and 192 with endometrioid endometrial cancer were analyzed. 87/239 (36%) of all endometrial cancers had BRCAness mutations identified. 7/47 (15%) in the serous cancer group and 80/192 (42%) in the endometrioid cancer group. Over a period of 5 years, 14 terminal events were noted in the cohort; 8 in the serous group all with BRCAness, and 6 in the endometrioid group all without BRCAness. When endometrial cancers were stratified based on presence or absence of BRCAness, overall survival (OS) was not seen to be different between the two groups (p = 0.13). The difference approached statistical significance when controlling for histology (p = 0.05). Conclusion: Similar to ovarian cancer, BRCAness mutations appear to be highly prevalent in endometrial cancers of all histologies. In fact it was identified in more than 1/3 of all endometrial cancers analyzed through the TCGA database. Although BRCAness did not appear to be an independent prognostic factor for OS, possibly due to the low number of terminal events, there appeared to be a trend towards significance in both types of cancers. These findings needs to be validated and could open the door to novel therapeutic strategies such as PARP inhibitors in endometrial cancer patients. doi:10.1016/j.ygyno.2015.07.044
Frequency of serous tubal intraepithelial carcinomas in primary peritoneal serous carcinomas M Zakhour, J. Lester, B.J. Rimel, C. Walsh, A. Li, B. Karlan, R. Leuchter, I. Cass Objectives: To determine the incidence of serous tubal intraepithelial carcinoma (STIC) in patients diagnosed with primary peritoneal serous carcinoma (PPSC) and their clinical outcomes. Methods: An IRB-approved retrospective chart review identified consecutive patients between 1/2002 and 4/2014 with a diagnosis of PPSC who underwent cytoreductive surgery at a single institution. Only patients with pathology reports that included bilateral salpingooophorectomies (BSO) and were reviewed within our institution were included. All patients met GOG criteria for PPSC: ovaries normal in size, involvement of extra-ovarian sites greater than involvement of ovarian surfaces, absent or minimal invasive disease in ovarian stroma. Patients with both representative and comprehensive sectioning of the fallopian tubes were included. Processing of the adnexa was at the discretion of the pathologist until 2011, when all adnexal specimens underwent comprehensive sectioning. Demographic, clinical, and histological information was abstracted from medical records. Results: Forty one consecutive patients were identified who met the criteria. Four patients had received neoadjuvant chemotherapy prior to surgery. Sixteen (39%) had comprehensive sectioning of the fallopian tubes, and 13 (32%) had concurrent STIC lesions noted in their path reports. Twenty four (59%) were Jewish, and 8 (20%) were BRCA mutation carriers. Median age, Jewish ethnicity, BRCA status, and average serum CA125 at diagnosis were comparable between the groups with and without STIC lesions. Ten of 16 (63%) patients with serial tubal sectioning were found to have STIC lesions, versus 3 of 25 (12%) who did not (p = 0.0014). Six of 13 (46%) patients with STIC have died of disease, versus 16 of 28 (57%) without STIC (p = 0.7). Six of 13 (46%) patients with STIC had progressive or recurrent disease, versus 23 of 28 patients (82%) without STIC (p = 0.028). Median overall survival was comparable between the two groups, 46 months for those with STIC and 44 months for those without. All STIC lesions involved the tubal fimbriae. Conclusion: STIC lesions are present in one-third of cases of PPSC in this cohort, which further supports that the fallopian tube may be the source of pelvic serous carcinomas. Comprehensive tubal sectioning yields higher detection rate of STIC lesions in patients with PPSC. Patients with concurrent STIC lesions had slightly better clinical outcomes.
Median age Comprehensive sectioning Jewish BRCA mutation carriers Mean CA125 at diagnosis Dead of disease Progressive or recurrent disease Median OS
STIC present (n = 13)
STIC not present (n = 28)
P
65 10 (77%) 8 (62%) 4 (31%) 2096 6 (46%) 6 (46%) 46 months
64 6 (22%) 16 (59%) 4 (15%) 1409 15 (56%) 22 (81%) 44 months
n.s. 0.0014 n.s. n.s. n.s. 0.7 0.028 n.s.
doi:10.1016/j.ygyno.2015.07.045
Surveillance and health outcomes for BRCA mutation carriers following risk-reducing salpingo-oophorectomy (RRSO) E. Prendergast, M. Green, M. Zakhour, J. Lester, A. Li, C. Walsh, B.J. Rimel, R. Leuchter, B. Karlan. I. Cass Department of Obstetrics & Gynecology, Division of Gynecologic Oncology, Cedars-Sinai Medical Center, Los Angeles, CA, USA Objectives: To characterize patterns of health surveillance for BRCA1 and BRCA2 mutation carriers following risk-reducing salpingo-oophorectomy (RRSO).
Abstracts / Gynecologic Oncology 139 (2015) 178–207
Methods: After IRB approval, a retrospective review of health surveillance and outcomes for BRCA1/2 mutation carriers following RRSO was performed. Women with occult carcinoma at RRSO were excluded from analysis. The frequency of hormone replacement therapy (HRT or ERT), abnormal uterine bleeding and cervical pathology were abstracted. Surveillance for bone loss, breast cancer after RRSO, and subsequent primary serous peritoneal cancer (PSPC) was recorded. Results: We identified 109 BRCA mutation carriers who underwent RRSO: 50 BRCA1, 44 BRCA2, and 2 BRCA-NOS with median ages of 45, 44, and 43 respectively. Median duration of follow up was 5 years. Sixty-one (56%) women had a concomitant hysterectomy. Forty-four (40%) women used either HRT or ERT for an average of 4 ± 2.8 years. Women who had hysterectomy were equally likely to use HRT as those with a uterus, 43% vs. 42%. Thirty-eight (50%) premenopausal women used HRT compared to 6 (18%) postmenopausal women [p = 0.002]. 10% of women with a uterus had abnormal bleeding. Eight (17%) underwent endometrial biopsy with 1 diagnosis of cancer. Evaluation of abnormal cervical pap smears in 4 patients were unremarkable. Four women were diagnosed with breast cancer following RRSO (7%). Two were diagnosed on MRI, 1 on mammogram and 1 on prophylactic mastectomy. Following RRSO, 30 women underwent at least one surveillance ultrasound for PSPC; 7 underwent further negative evaluation. Sixty-one (56%) underwent CA125 surveillance with no abnormal findings. CA-125 values did not change significantly before and after RRSO. No patients were diagnosed with PSPC. Half of the women underwent dual-energy X-ray absorptiometry (DXA) testing. Seven (13.2%) were diagnosed with osteoporosis an average of 16.5 months following RRSO. Conclusion: Health surveillance patterns vary widely for this cohort of patients. BRCA mutation carriers who had their uterus in situ were at very low risk of subsequent pathology. Optimal surveillance for PSPC is uncertain, however, CA 125 may be a superior screening modality to pelvic ultrasound. Screening for bone loss is underutilized in this cohort. Guidelines should be developed to optimize long-term survival in this high-risk cohort of women. doi:10.1016/j.ygyno.2015.07.046
The receptor tyrosine kinase discoidin domain receptor 2 promotes invasion via epithelial mesenchymal transition in ovarian cancer L. Divinea, W. Gritherb, A. Gibsona, G. Longmoreb, K. Fuha. aDivision of Gynecologic Oncology, Dept of Obstetrics and Gynecology, Washington University, St. Louis, MO, USA, bDivision of Molecular Oncology, Dept of Medicine, Department of Cell Biology and Physiology, Washington University, St. Louis, MO, USA Objectives: A collagen-binding receptor tyrosine kinase, discoidin domain receptor 2 (DDR2), has been implicated in regulation of breast and lung cancer metastasis and is currently a subarm in the NCI MATCH trial. Our objective is to evaluate the role of DDR2 in invasion and metastasis of ovarian cancer. Methods: Immunohistochemical staining of DDR2 was performed. Ovarian cancer cell lines, A2780 and ES2, were used to perform migration and invasion assays. DDR2 and scrambled control were inactivated in A2780 and ES2 cell lines using shRNA technology and will be referred to as shDDR2 and shControl, respectively. Invasion assays were performed using collagen I and fibronectin coated semipermeable membranes (i.e. Matrigel). ES2 shControl and shDDR2 cells were injected intraperitoneally into nude mice. Western blot was performed to evaluate DDR2, E- and N-cadherin and SNAIL expression. One-way ANOVA was used to compare DDR2 expression among benign, early stage, and advanced stage tumors. Results: The majority of ascites-derived primary ovarian cancer cells expressed DDR2. High immunohistochemical expression of DDR2 was found in 74% (28/38) of advanced stage, high-grade serous
189
tumors compared to 44% (79/179) of early stage, high-grade serous tumors, p b 0.0001. All metastatic tumor specimens had high DDR2 expression (12/12 specimens). DDR2 was also found to regulate invasion and migration. Matrigel invasion assays showed a decrease in tumor cell invasion in shDDR2 compared to shControl in ES2 and A2780 cells (27 vs 110 cells/high power field (hpf), p b 0.001 and 23 vs 40 cells/hpf, p = 0.0027, respectively). DDR2-mediated tumor cell invasion is associated with epithelial mesenchymal transition (EMT): DDR2 deficient cells had lower mesenchymal marker (N-cadherin and SNAIL) expression and higher epithelial marker (E-cadherin) expression compared to DDR2 expressing cells. Additionally, an intraperitoneal ES2 cell line xenograft model showed that DDR2 deficient cells had significantly less tumor nodules compared to DDR2 expressing cells (mean of 12 vs. 28, respectively p = 0.005). Conclusion: DDR2 is highly expressed in advanced stage and metastatic ovarian cancer tumors and plays a significant role in invasion and metastasis both in vitro and in vivo. DDR2-regulated invasion is associated with EMT markers and is a promising therapeutic target in metastatic ovarian cancer. doi:10.1016/j.ygyno.2015.07.047
Disulfide cross-linked micelle based nanoparticle-delivered paclitaxel in combination with platinum agents in ovarian cancer models R. Stephensona, M. Petersena, S. Hazarib, Y. Lib, E. Alvareza, K. Lamb. a Division of Gynecologic Oncology, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA, b Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA Objectives: Platinum and taxane based chemotherapy is standard treatment of ovarian carcinoma. Phase III trials have shown a 25% reduction of risk of death with combination intraperitoneal (IP) and IV platinum and taxane, but with substantial toxicity. We previously demonstrated the efficacy of a telodendrimer-based nanoparticle delivery system of paclitaxel in an in vivo model compared to free drug. New classes of nano-carriers, disulfide cross-linked micelles (DCM) using reducing agents, are less toxic in an ovarian cancer xenograft mouse model, prevent premature drug release and may enhance therapeutic effect. Our objective is to measure the effect of combination platinum with disulfide cross-linked micelle loaded paclitaxel (DCM-PTX) using in vitro and in vivo models. We assessed the therapeutic effect and toxicity of DCM-PTX in combination with platinum agents delivered IV and IP in an orthotopic xenograft ovarian cancer model. Methods: The physico-chemical characteristics and drug loading of micelles were determined. ED50 was calculated for each agent. The cytotoxicity of DCM-PTX in combination with cisplatin and carboplatin was evaluated in SKOV-3-LUC and A2780 cell lines using a tetrazolium-dye (MTT) cytotoxicity assay. Synergism was quantified using Compusyn software. A2780 human ovarian cancer cells with stably transfected Luciferase were used to establish an IP ovarian cancer model in nude mice. Four groups of 10 nude mice with ovarian cancer xenografts were treated with vehicle, paclitaxel, low dose or high dose DCM-PTC IV and IP in combination with vehicle or IP cisplatin. Bioluminescence imaging was used to follow tumor response. Results: Both cell lines displayed sensitivity to DCM-PTX and a synergistic effect in combination with carboplatin and cisplatin in vitro. The in vivo study showed a 25% (p 0.01) improvement in median overall survival in the high dose DCM-PTX when compared to therapeutic control. Toxicity assessments demonstrated decreased hepatotoxicity in DCM-PTX groups.
Abstracts / Gynecologic Oncology 139 (2015) 178–207
independent experiments were performed to identify differentially expressed genes from tumors of ovarian serous histology (p ≤ 0.01). These differentially expressed genes were then compared to identify a set of genes that is uniformly overexpressed in both uterine and ovarian serous tumors. Results: This analysis revealed only 3 genes (FBXL5, EYA2, PPP2R2D) to be consistently overexpressed in serous cancers, independent of the site of origin. In contrast, 60 genes were identified to be overexpressed consistently in the endometrioid ovarian and uterine tumors. Conclusion: Patients with ovarian and uterine cancers of serous histology appear to possess a distinct genetic profile with few to no overlapping genes in common. Further analysis into the genetic and molecular profiles of these common and aggressive tumors is warranted, and could open the door to new therapeutic strategies. doi:10.1016/j.ygyno.2015.07.043
BRCAness in endometrial cancer J.M. Stephan, E. Cohen, J. Gonzalez. Bosquet University of Iowa Hospitals and Clinics Objectives: The term BRCAness describes the phenotypic traits that some sporadic ovarian tumors share with tumors in BRCA1/2 germline mutation carriers and reflects similar causative molecular abnormalities. Molecular profiling through The Cancer Genome Atlas database (TCGA) revealed BRCA-related defects in almost half of the cases of ovarian cancer, opening the gate to new therapeutic strategies in these patients. We sought to evaluate the frequency, prognostic significance, and potential clinical application of BRCAness in both serous and endometrioid endometrial cancer. Methods: Mutation data as well as clinical and follow-up information were downloaded from TCGA server. When cancer cells acquire mutations within the homologous recombination (HR) DNA-repair pathway (as happens with BRCA1&2 mutations) we considered them to have a ‘BRCAness phenotype’. Mutations on HR DNA-repair genes from TCGA databases for both ovarian and endometrial cancer were recorded. Kaplan–Meier and Log-rank survivorship were calculated for both clinical and mutation variables of interest for both cancers. Cox proportional hazardratios were computed to identify independent variables associated with survival. Results: 47 patients with serous endometrial cancer and 192 with endometrioid endometrial cancer were analyzed. 87/239 (36%) of all endometrial cancers had BRCAness mutations identified. 7/47 (15%) in the serous cancer group and 80/192 (42%) in the endometrioid cancer group. Over a period of 5 years, 14 terminal events were noted in the cohort; 8 in the serous group all with BRCAness, and 6 in the endometrioid group all without BRCAness. When endometrial cancers were stratified based on presence or absence of BRCAness, overall survival (OS) was not seen to be different between the two groups (p = 0.13). The difference approached statistical significance when controlling for histology (p = 0.05). Conclusion: Similar to ovarian cancer, BRCAness mutations appear to be highly prevalent in endometrial cancers of all histologies. In fact it was identified in more than 1/3 of all endometrial cancers analyzed through the TCGA database. Although BRCAness did not appear to be an independent prognostic factor for OS, possibly due to the low number of terminal events, there appeared to be a trend towards significance in both types of cancers. These findings needs to be validated and could open the door to novel therapeutic strategies such as PARP inhibitors in endometrial cancer patients. doi:10.1016/j.ygyno.2015.07.044
Frequency of serous tubal intraepithelial carcinomas in primary peritoneal serous carcinomas M Zakhour, J. Lester, B.J. Rimel, C. Walsh, A. Li, B. Karlan, R. Leuchter, I. Cass Objectives: To determine the incidence of serous tubal intraepithelial carcinoma (STIC) in patients diagnosed with primary peritoneal serous carcinoma (PPSC) and their clinical outcomes. Methods: An IRB-approved retrospective chart review identified consecutive patients between 1/2002 and 4/2014 with a diagnosis of PPSC who underwent cytoreductive surgery at a single institution. Only patients with pathology reports that included bilateral salpingooophorectomies (BSO) and were reviewed within our institution were included. All patients met GOG criteria for PPSC: ovaries normal in size, involvement of extra-ovarian sites greater than involvement of ovarian surfaces, absent or minimal invasive disease in ovarian stroma. Patients with both representative and comprehensive sectioning of the fallopian tubes were included. Processing of the adnexa was at the discretion of the pathologist until 2011, when all adnexal specimens underwent comprehensive sectioning. Demographic, clinical, and histological information was abstracted from medical records. Results: Forty one consecutive patients were identified who met the criteria. Four patients had received neoadjuvant chemotherapy prior to surgery. Sixteen (39%) had comprehensive sectioning of the fallopian tubes, and 13 (32%) had concurrent STIC lesions noted in their path reports. Twenty four (59%) were Jewish, and 8 (20%) were BRCA mutation carriers. Median age, Jewish ethnicity, BRCA status, and average serum CA125 at diagnosis were comparable between the groups with and without STIC lesions. Ten of 16 (63%) patients with serial tubal sectioning were found to have STIC lesions, versus 3 of 25 (12%) who did not (p = 0.0014). Six of 13 (46%) patients with STIC have died of disease, versus 16 of 28 (57%) without STIC (p = 0.7). Six of 13 (46%) patients with STIC had progressive or recurrent disease, versus 23 of 28 patients (82%) without STIC (p = 0.028). Median overall survival was comparable between the two groups, 46 months for those with STIC and 44 months for those without. All STIC lesions involved the tubal fimbriae. Conclusion: STIC lesions are present in one-third of cases of PPSC in this cohort, which further supports that the fallopian tube may be the source of pelvic serous carcinomas. Comprehensive tubal sectioning yields higher detection rate of STIC lesions in patients with PPSC. Patients with concurrent STIC lesions had slightly better clinical outcomes.
Median age Comprehensive sectioning Jewish BRCA mutation carriers Mean CA125 at diagnosis Dead of disease Progressive or recurrent disease Median OS
STIC present (n = 13)
STIC not present (n = 28)
P
65 10 (77%) 8 (62%) 4 (31%) 2096 6 (46%) 6 (46%) 46 months
64 6 (22%) 16 (59%) 4 (15%) 1409 15 (56%) 22 (81%) 44 months
n.s. 0.0014 n.s. n.s. n.s. 0.7 0.028 n.s.
doi:10.1016/j.ygyno.2015.07.045
Surveillance and health outcomes for BRCA mutation carriers following risk-reducing salpingo-oophorectomy (RRSO) E. Prendergast, M. Green, M. Zakhour, J. Lester, A. Li, C. Walsh, B.J. Rimel, R. Leuchter, B. Karlan. I. Cass Department of Obstetrics & Gynecology, Division of Gynecologic Oncology, Cedars-Sinai Medical Center, Los Angeles, CA, USA Objectives: To characterize patterns of health surveillance for BRCA1 and BRCA2 mutation carriers following risk-reducing salpingo-oophorectomy (RRSO).
Abstracts / Gynecologic Oncology 139 (2015) 178–207
Methods: After IRB approval, a retrospective review of health surveillance and outcomes for BRCA1/2 mutation carriers following RRSO was performed. Women with occult carcinoma at RRSO were excluded from analysis. The frequency of hormone replacement therapy (HRT or ERT), abnormal uterine bleeding and cervical pathology were abstracted. Surveillance for bone loss, breast cancer after RRSO, and subsequent primary serous peritoneal cancer (PSPC) was recorded. Results: We identified 109 BRCA mutation carriers who underwent RRSO: 50 BRCA1, 44 BRCA2, and 2 BRCA-NOS with median ages of 45, 44, and 43 respectively. Median duration of follow up was 5 years. Sixty-one (56%) women had a concomitant hysterectomy. Forty-four (40%) women used either HRT or ERT for an average of 4 ± 2.8 years. Women who had hysterectomy were equally likely to use HRT as those with a uterus, 43% vs. 42%. Thirty-eight (50%) premenopausal women used HRT compared to 6 (18%) postmenopausal women [p = 0.002]. 10% of women with a uterus had abnormal bleeding. Eight (17%) underwent endometrial biopsy with 1 diagnosis of cancer. Evaluation of abnormal cervical pap smears in 4 patients were unremarkable. Four women were diagnosed with breast cancer following RRSO (7%). Two were diagnosed on MRI, 1 on mammogram and 1 on prophylactic mastectomy. Following RRSO, 30 women underwent at least one surveillance ultrasound for PSPC; 7 underwent further negative evaluation. Sixty-one (56%) underwent CA125 surveillance with no abnormal findings. CA-125 values did not change significantly before and after RRSO. No patients were diagnosed with PSPC. Half of the women underwent dual-energy X-ray absorptiometry (DXA) testing. Seven (13.2%) were diagnosed with osteoporosis an average of 16.5 months following RRSO. Conclusion: Health surveillance patterns vary widely for this cohort of patients. BRCA mutation carriers who had their uterus in situ were at very low risk of subsequent pathology. Optimal surveillance for PSPC is uncertain, however, CA 125 may be a superior screening modality to pelvic ultrasound. Screening for bone loss is underutilized in this cohort. Guidelines should be developed to optimize long-term survival in this high-risk cohort of women. doi:10.1016/j.ygyno.2015.07.046
The receptor tyrosine kinase discoidin domain receptor 2 promotes invasion via epithelial mesenchymal transition in ovarian cancer L. Divinea, W. Gritherb, A. Gibsona, G. Longmoreb, K. Fuha. aDivision of Gynecologic Oncology, Dept of Obstetrics and Gynecology, Washington University, St. Louis, MO, USA, bDivision of Molecular Oncology, Dept of Medicine, Department of Cell Biology and Physiology, Washington University, St. Louis, MO, USA Objectives: A collagen-binding receptor tyrosine kinase, discoidin domain receptor 2 (DDR2), has been implicated in regulation of breast and lung cancer metastasis and is currently a subarm in the NCI MATCH trial. Our objective is to evaluate the role of DDR2 in invasion and metastasis of ovarian cancer. Methods: Immunohistochemical staining of DDR2 was performed. Ovarian cancer cell lines, A2780 and ES2, were used to perform migration and invasion assays. DDR2 and scrambled control were inactivated in A2780 and ES2 cell lines using shRNA technology and will be referred to as shDDR2 and shControl, respectively. Invasion assays were performed using collagen I and fibronectin coated semipermeable membranes (i.e. Matrigel). ES2 shControl and shDDR2 cells were injected intraperitoneally into nude mice. Western blot was performed to evaluate DDR2, E- and N-cadherin and SNAIL expression. One-way ANOVA was used to compare DDR2 expression among benign, early stage, and advanced stage tumors. Results: The majority of ascites-derived primary ovarian cancer cells expressed DDR2. High immunohistochemical expression of DDR2 was found in 74% (28/38) of advanced stage, high-grade serous
189
tumors compared to 44% (79/179) of early stage, high-grade serous tumors, p b 0.0001. All metastatic tumor specimens had high DDR2 expression (12/12 specimens). DDR2 was also found to regulate invasion and migration. Matrigel invasion assays showed a decrease in tumor cell invasion in shDDR2 compared to shControl in ES2 and A2780 cells (27 vs 110 cells/high power field (hpf), p b 0.001 and 23 vs 40 cells/hpf, p = 0.0027, respectively). DDR2-mediated tumor cell invasion is associated with epithelial mesenchymal transition (EMT): DDR2 deficient cells had lower mesenchymal marker (N-cadherin and SNAIL) expression and higher epithelial marker (E-cadherin) expression compared to DDR2 expressing cells. Additionally, an intraperitoneal ES2 cell line xenograft model showed that DDR2 deficient cells had significantly less tumor nodules compared to DDR2 expressing cells (mean of 12 vs. 28, respectively p = 0.005). Conclusion: DDR2 is highly expressed in advanced stage and metastatic ovarian cancer tumors and plays a significant role in invasion and metastasis both in vitro and in vivo. DDR2-regulated invasion is associated with EMT markers and is a promising therapeutic target in metastatic ovarian cancer. doi:10.1016/j.ygyno.2015.07.047
Disulfide cross-linked micelle based nanoparticle-delivered paclitaxel in combination with platinum agents in ovarian cancer models R. Stephensona, M. Petersena, S. Hazarib, Y. Lib, E. Alvareza, K. Lamb. a Division of Gynecologic Oncology, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA, b Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA Objectives: Platinum and taxane based chemotherapy is standard treatment of ovarian carcinoma. Phase III trials have shown a 25% reduction of risk of death with combination intraperitoneal (IP) and IV platinum and taxane, but with substantial toxicity. We previously demonstrated the efficacy of a telodendrimer-based nanoparticle delivery system of paclitaxel in an in vivo model compared to free drug. New classes of nano-carriers, disulfide cross-linked micelles (DCM) using reducing agents, are less toxic in an ovarian cancer xenograft mouse model, prevent premature drug release and may enhance therapeutic effect. Our objective is to measure the effect of combination platinum with disulfide cross-linked micelle loaded paclitaxel (DCM-PTX) using in vitro and in vivo models. We assessed the therapeutic effect and toxicity of DCM-PTX in combination with platinum agents delivered IV and IP in an orthotopic xenograft ovarian cancer model. Methods: The physico-chemical characteristics and drug loading of micelles were determined. ED50 was calculated for each agent. The cytotoxicity of DCM-PTX in combination with cisplatin and carboplatin was evaluated in SKOV-3-LUC and A2780 cell lines using a tetrazolium-dye (MTT) cytotoxicity assay. Synergism was quantified using Compusyn software. A2780 human ovarian cancer cells with stably transfected Luciferase were used to establish an IP ovarian cancer model in nude mice. Four groups of 10 nude mice with ovarian cancer xenografts were treated with vehicle, paclitaxel, low dose or high dose DCM-PTC IV and IP in combination with vehicle or IP cisplatin. Bioluminescence imaging was used to follow tumor response. Results: Both cell lines displayed sensitivity to DCM-PTX and a synergistic effect in combination with carboplatin and cisplatin in vitro. The in vivo study showed a 25% (p 0.01) improvement in median overall survival in the high dose DCM-PTX when compared to therapeutic control. Toxicity assessments demonstrated decreased hepatotoxicity in DCM-PTX groups.