Therapy For Ovarian Cancer Patients Research Articles

Current insights into the metastasis of epithelial ovarian cancer - hopes and hurdles.

Ovarian cancer is the most lethal gynecologic cancer and the fifth leading cause of cancer-related mortality in women worldwide. Despite various attempts to improve the diagnosis and therapy of ovarian cancer patients, the survival rate for these patients is still dismal, mainly because most of them are diagnosed at a late stage. Up to 90% of ovarian cancers arise from neoplastic transformation of ovarian surface epithelial cells, and are usually referred to as epithelial ovarian cancer (EOC). Unlike most human cancers, which are disseminated through blood-borne metastatic routes, EOC has traditionally been thought to be disseminated through direct migration of ovarian tumor cells to the peritoneal cavity and omentum via peritoneal fluid. It has recently been shown, however, that EOC can also be disseminated through blood-borne metastatic routes, challenging previous thoughts about ovarian cancer metastasis. Here, we review our current understanding of the most updated cellular and molecular mechanisms underlying EOC metastasis and discuss in more detail two main metastatic routes of EOC, i.e., transcoelomic metastasis and hematogenous metastasis. The emerging concept of blood-borne EOC metastasis has led to exploration of the significance of circulating tumor cells (CTCs) as novel and non-invasive prognostic markers in this daunting cancer. We also evaluate the role of tumor stroma, including cancer associated fibroblasts (CAFs), tumor associated macrophages (TAMs), endothelial cells, adipocytes, dendritic cells and extracellular matrix (ECM) components in EOC growth and metastasis. Lastly, we discuss therapeutic approaches for targeting EOC. Unraveling the mechanisms underlying EOC metastasis will open up avenues to the design of new therapeutic options. For instance, understanding the molecular mechanisms involved in the hematogenous metastasis of EOC, the biology of CTCs, and the detailed mechanisms through which EOC cells take advantage of stromal cells may help to find new opportunities for targeting EOC metastasis.

Upregulation of ITGBL1 predicts poor prognosis and promotes chemoresistance in ovarian cancer

Ovarian cancer remains one of the most lethal malignancies in women and the unfavorable prognosis and frequent recurrence are mainly due to the chemoresistance. However, the main mechanism underlying chemoresistance is still elusive. To determine the role and biological function of ITGBL1 in ovarian cancer chemoresistance. Immunohistochemical staining was used to determine the expression of ITGBL1 in ovarian cancer tissues. The association between ITGBL1 expression and clinicopathological features and survival was determined. Functional analysis including cell viability, apoptosis assays were performed after chemo drugs treatment to confirm the role of ITGBL1 in chemoresistance. In vivo tumor growth assay was used to detect the chemosensitivity of tumor cells. Western blot was used to detect the expression of indicated proteins. We noticed that ITGBL1 expression was significantly upregulated in ovarian cancer tissues compared to that in adjacent non-cancer tissues and high expression of ITGBL1 was significantly associated with lymph node invasion and advanced FIGO stage. More importantly, high ITGBL1 was an independent prognostic factor of ovarian cancer. Further experiments demonstrated that ITGBL1 promoted tumor cell resistant to chemo drugs both in vitro and in vivo. Mechanically, we found that ITGBL1 could activate PI3K/Akt signaling and using PI3K/Akt inhibitor could abrogate ITGBL1 induced chemoresistance. Our findings indicate that upregulation of ITGBL1 has important clinical significance and drives chemoresistance in ovarian cancer. Detection and depletion of ITGBL1 might be the potential approaches for diagnosis and therapy for ovarian cancer patients.

Revamping the ovarian tumour microenvironment with an oncolytic adenovirus yields enhanced tumour-infiltrating lymphocyte anti-tumour activity

Abstract Background The ovarian tumour microenvironment is an abundant source of tumour-infiltrating lymphocytes (TILs) which can be readily harnessed for infusion in the context of adoptive TIL therapy. This strategy has been proven feasible, but it appears clinically ineffective in ovarian cancer patients due to the absence of tumour-reactive TILs and the presence of immunosuppression. Hence, we hypothesized that an oncolytic adenovirus expressing Tumour Necrosis Factor (TNF)-alpha(a) and Interleukin (IL)-2 (Ad5/3-E2F-D24-hIL-2-IRES-TNFa; TILT-123) could overcome this by generating a proinflammatory microenvironment and reinvigorating TIL anti-tumour activity. Methods Fresh explants from metastatic or primary tumour sites were obtained from stage III-IV ovarian cancer patients and short-term cultures were established in the absence or presence of oncolytic adenovirus. The remainder of the tumour explant was used to generate clinically relevant TILs which were co-cultured with autologous T cell-depleted single cell suspensions pre-treated with or without oncolytic adenoviruses. Cytokine content changes and TIL reactivity was assessed during culture by flow cytometry or interferon (IFN) gamma(g) enzyme-linked immune sorbent assay. Results Treatment of short-term cultures with oncolytic adenovirus coding for TNFa and IL-2 introduced profound changes within the microenvironment, which were characterized by an increase in proinflammatory cytokines and decrease in suppressive cytokines. Further benefits were seen in T-cell depleted ovarian cancer single-cell suspensions infected with cytokine-coding oncolytic adenovirus, which enabled significant production of IFNg by autologous TILs. Such levels were not seen in co-cultures where no virus or the backbone oncolytic adenovirus (no cytokine transgenes) was added. Conclusion These data illustrate the potential of oncolytic adenovirus coding for TNFa and IL-2 to rewire the ovarian tumour microenvironment for effective TIL anti-tumour reactivity. This approach may improve the efficacy of adoptive TIL therapy in ovarian cancer patients, thus warranting further clinical investigation. Legal entity responsible for the study TILT Biotherapeutics Ltd. Funding TILT Biotherapeutics Ltd. Disclosure J.M. Santos: Full / Part-time employment: TILT Biotherapeutics Ltd. V. Cervera-Carrascon: Full / Part-time employment: TILT Biotherapeutics Ltd. M. Siurala: Full / Part-time employment: TILT Biotherapeutics Ltd. T. de Gruijl: Advisory / Consultancy: TILT Biotherapeutics Ltd. A. Hemminki: Shareholder / Stockholder / Stock options, Full / Part-time employment, Officer / Board of Directors: TILT Biotherapeutics Ltd. All other authors have declared no conflicts of interest.

Cytoreductive surgery and HIPEC (hyperthermic intraperitoneal chemotherapy) in combined treatment of ovarian cancer: time for the beginning of personalized therapy?

Abstract Background and objectives. During the two past decades, a new therapeutic approach to ovarian cancer (OC) has been developed. This combines cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). However, almost no data exist regarding the utility of biomarkers of morphological heterogeneity as prognostic factors in such patients. Methods. A retrospective study of the effectiveness of CRS and HIPEC was carried out in 59 patients with ovarian cancer. Biomarkers of morphological heterogeneity of OC were studied as prognostic factors: OC pathogenic types (based on the identification of р53 mutated gene protein expression) and homologous recombination deficit (basing on the identification of BRCA 1 gene expression status). Results. The survival of patients reliably differed with the division into two pathogenetic OC types established by immunohistochemistry: the median disease-free survival of type I OC patients was 14±1.7 months, type ІІ – 8±1.6 months (р = 0.007); the median overall survival of type I OC patients was 23.5±6.7 months, type ІІ – 12±1.9 months (р = 0.017). The median overall survival of patients with the somatic mutation of BRCA 1 gene and complete cytoreduction was 22±4.8 months, and without the somatic mutation of BRCA 1 gene – 12±3.3 months (р = 0.047). Conclusions. These data demonstrate that identification of the pathogenetic type of OC and BRCA 1 status may be useful for the personalized therapy of ovarian cancer patients treated with CRS/HIPEC.

Clinical benefit of bevacizumab in Mexican ovarian cancer patients according to the intention of treatment by the oncologist.

e17097 Background: Ovarian cancer (OC) is the first cause of gynecological cancer, and the fifth cause of women cancer-death in US. In Mexico, more than 4,500 new cases of ovarian cancer are diagnosed yearly and it represents the second cause of gynecological cancer mortality. Bevacizumab (BVZ) is an antiangiogenic antibody that has been approved for first-line and recurrence therapy in OC patients. The aim of the study was to evaluate the clinical benefit of BVZ in different lines of treatment in Mexican OC patients. Methods: A total of 94 OC patients treated with BVZ were recruited at the Ovarian Cancer Program of the Instituto Nacional de Cancerología, from February 2012 to September 2018. Clinicopathological characteristics and toxicity was correlated with line of treatment. PFS curves were estimated by the Kaplan–Meier method, while comparisons among groups were analyzed with log-rank or Breslow tests. Results: Most of the patients were stage IIIC (69.1%) with HGSP histology (73.4%). 24 patients (25.5%) received BVZ as first-line treatment before debulking surgery (50% for suboptimal and 45.8% for optimal cytoreduction). 48 patients (51.1%) received BVZ for second-line (72.9% after a platinum-resistant and 27.1% after a platinum-sensitive recurrence) and 22 patients (23.4%) for three or more lines of treatment. Venous thromboembolic events (VTE) were more frequent in multi-treated patients ( P= 0.030). The median PFS was 23.7, 11.7 and 5.8 months for first, second and third or more lines, respectively. Patients with optimal debulking surgery had a better PFS compared with suboptimal and BVZ in first-line patients (24.8 vs 20.9; P= 0.050). Patients with BVZ in second-line who are a platinum-sensitive recurrence had better PFS compared to those with a platinum-resistant disease (15.1 vs 7.6; P= 0.040). Conclusions: OC patients had clinical benefit from treatment with BVZ when used as first-line and first recurrence treatments. The use of BVZ for third or later line treatment has a questionable benefit and is associated with a higher rate of VTE. Also, we highlight that 77% of the patients had the greatest-benefit while 33% had limited-benefit.

Bevacizumab Plus Direct Oral Anticoagulant Therapy in Ovarian Cancer Patients with Distal Deep Vein Thrombosis.

Administration of bevacizumab to ovarian cancer patients with distal deep vein thrombosis (DVT) is problematic because of lack of evidence about the likely outcomes. We conducted a preliminary study in ovarian cancer patients with DVT who received bevacizumab combined with a direct oral anticoagulant (DOAC). We retrospectively investigated patients with advanced or recurrent epithelial ovarian cancer and distal DVT diagnosed by ultrasonography who underwent chemotherapy containing bevacizumab (15mg/kg every 3weeks) combined with DOAC therapy. Bevacizumab was administered to 88 patients, including 7 patients (7.9%) receiving concomitant DOAC therapy for distal DVT. In these 7 patients, the median body mass index was 21.3kg/m2, median D-dimer level at diagnosis of DVT was 4.3µg/mL, and median duration of DOAC therapy was 8months. Adverse events during DOAC therapy were grade 1 epistaxis and grade 1 hemorrhoidal bleeding in one patient each. DVT resolved in four patients and was unchanged in three patients, with no central progression or secondary thromboembolism. In ovarian cancer patients who have distal DVT, bevacizumab can possibly be administered safely when combined with a DOAC. To confirm this finding, further investigation on a larger scale will be required.

What is the Current Effectiveness of Olaparib for Breast Cancer Patients with a BRCA Mutation? A Systematic Review

Background:The Poly (ADP-ribose) polymerase inhibitor olaparib, acts against cancer cells in people with breast cancer pre-disposition gene mutations (BRCAm). Despite US and EU approval as a therapy for ovarian cancer patients with BRCAm, but research into olaparib therapy for breast cancer patients with BRCAm is in its infancy.Objective:As no systematic review has yet been undertaken to synthesise clinical trials looking at olaparib as a therapy for breast cancer patients with BRCAm, this systematic review aims to establish the current effectiveness of olaparib as a treatment for these patients.Methods:CINAHL, MEDLINE, Royal College of Nursing, Cochrane Library, Joanna Briggs Institute, Centre for Reviews and Dissemination, Internurse, Embase, Google Scholar and PubMed databases were searched, supplemented by a grey literature search, hand searching and cross-referencing. Authors independently reviewed and graded the studies also using Kmetet al. scoring system.Results:One long-term case study and six clinical trials were included. Heterogeneity prevented statistical meta-analysis, meaning only narrative synthesis was possible. The overall clinical benefit of olaparib appears to be greater and longer lived in BRCAm carriers compared to BRCAwt, and also when compared to standard chemotherapy treatments.Conclusion:Implications for nursing: nurses working in this field should be aware that the most compelling results were found in the subset of patients who harbour a BRCA mutation, meaning that olaparib should be regarded as a clinically effective potential therapy for these patients. Larger, longer-term trials including comparator arms are required to demonstrate benefits including overall survival, adverse effects and quality of life.

Antiangiogenesis therapy in ovarian cancer patients

Antiangiogenesis therapy has been demonstrated to prolong the free survival with tolerable toxicity. However the efficacy of these drugs in overall survival (OS) remains controversial. This study was designed to assess the overall performance of antiangiogenesis therapy in improving the survival of ovary cancer (OC) patients. Electronic database of PubMed, Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials were searched to identify relevant clinical randomized control trial (RCTs) assessing the therapeutic value of antiangiogenesis therapy in OC patients during 2011 to 2017. Additionally, abstracts of annual meetings were also conducted. Only English articles were considered. Progression free survival (PFS), OS, and objective response rate (ORR) were obtained from eligible RCTs. The HRs for time-to-event variables and ORs for dichotomous outcomes with their 95% CIs were used for this meta-analysis. All the statistical analyses were carried out by Stata 11.0 software using a fixed or random-models according to heterogeneity. A total of 15 RCTs including 9359 patients were recruited into this meta-analysis. Addition of antiangiogenic agents improved PFS (HR = 0.71, 95% CI 0.62-0.81, P < .001), OS (HR = 0.92, 95% CI 0.86-0.98, P = .008) and ORR (OR = 1.74, 95% CI 1.27-2.39, P = .001) compared to placebo or chemotherapy alone in overall analysis. Antiangiogenic agents prolonged both PFS (HR = 0.58, 95% CI 0.52-0.65, P = .000) and OS (HR=0.84, 95% CI 0.76-0.92, P = .000) in recurrent settings but only PFS in primary settings (HR = 0.88, 95% CI 0.79-0.98, P = .020), longer PFS and OS in both platinum-sensitive recurrent patients (HR = 0.56, 95% CI 0.48-0.64, P = .000, PFS; HR = 0.86, 95% CI 0.76-0.98, P = .027, OS) as well as platinum-resistant recurrent cases (HR = 0.54, 95% CI 0.41-0.71, P = .000, PFS; HR = 0.84, 95% CI 0.71-0.98, P = .029, OS). Throughout therapy improved PFS (HR = 0.66, 95% CI 0.57-0.76, P < .001) and OS (HR = 0.89, 95% CI 0.83-0.96, P = .001). However the maintenance therapy of antiangiogenic agents was irrelevant to a longer PFS or OS. Based on the available studies, antiangiogenic agents play an important role in the survival of OC patients. More randomized controlled trials are needed to reach more convinced conclusion.

Response rates to second-line platinum-based therapy in ovarian cancer patients challenge the clinical definition of platinum resistance

ObjectiveThe aim of this study was to compare response rates and survival in women with “platinum resistant” epithelial ovarian cancer (EOC) who received further platinum-based or non‑platinum chemotherapy for treatment at first relapse. MethodsPatients with high-grade EOC (including fallopian tube and peritoneal cancer) of all histologies recruited to the Australian Ovarian Cancer Study (AOCS) and treated with platinum-based primary chemotherapy were included. Response to second-line chemotherapy, overall survival (OS) and survival after treatment for first progression (OS2) were determined in all histologies and separately in women with high-grade serous tumors. ResultsOf the 341 patients classified as platinum-resistant by the 6-month threshold, 243 (71%) were treated with chemotherapy at relapse. CA-125 response rates to platinum-based chemotherapy were significantly higher compared to non‑platinum chemotherapy (51% vs 21%, P < 0.001). Among patients with a platinum-free interval (PFI) of 3–6 months, OS2 in patients treated with platinum was significantly longer compared to individuals receiving non‑platinum-based treatment (median 17.67 months, 95% CI: 14.79–20.75 vs. 10.62 months, 95% CI: 8.02–12.72, P = 0.022). The patterns were similar when restricted to patients with high-grade serous histology. In patients with PFI <3 months, there was no significant difference in response or survival according to type of second-line treatment. ConclusionsOur findings further question the use of a 6-month PFI as an arbitrary threshold for subsequent treatment decision-making. Some patients considered “platinum resistant” still derive clinical benefit from platinum-based chemotherapy. Biomarkers of platinum sensitivity are needed in clinical practice to identify potential responders who should be offered re-treatment with platinum.

Predictive factors for prolonged response to olaparib as maintenance therapy in ovarian cancer patients with BRCA mutations.

5558Background: To investigate clinical factors predictive for prolonged progression-free survival (PFS) in ovarian cancer (OC) patients carrying BRCA mutations and receiving olaparib as a maintena...

Cardiovascular complications of antiangiogenic therapy in ovarian cancer patients

Therapy with angiogenesis inhibitors carries the risk for health and life-threatening cardio-vascular complications. The most common include the development of arterial hypertension, thromboembolic events (venous and arterial) and bleeding. This study provides a detailed analysis of their incidence, pathomechanisms as well as methods of prophylaxis and treatment among ovarian cancer patients receiving bevacizumab.

Abstract DPOC-003: DIFFERENTIAL PROTEIN EXPRESSION ANALYSIS OF SV40–IMMORTALIZED OVARIAN SURFACE, SV40–IMMORTALIZED FALLOPIAN TUBE AND OVARIAN CANCER SUBTYPE CELL LINE SECRETOMES BY ITRAQ®

Abstract BACKGROUND: In 2016, an estimated 22,280 new cases of ovarian cancer will be diagnosed with more than 14,000 women succumbing to the malignancy. These figures have not changed in the last decade. During this time new ovarian cancer models have been refined that involve either the fallopian tube or ovarian surface epithelial cells as the origin for tumorigenesis. With refined proteomics methodology, identification of new secreted biomarkers may be revealed that are specific to a primary fallopian tube or ovarian surface epithelium origin and may ultimately aid in the diagnosis, prognosis or therapy of ovarian cancer patients. EXPERIMENTAL PROCEDURES: The secretomes of eight cell lines, represented by SV40 immortalized fallopian tube (FT-194, FT-190), SV40 immortalized ovarian surface epithelium (1816-575), low-grade serous adenocarcinoma (HEY), high-grade serous adenocarcinoma (TOV-1946), clear cell adenocarcinoma (TOV21G), cisplatin-sensitive high-grade serous adenocarcinoma (A2780-S) and cisplatin-resistant high-grade serous adenocarcinoma (A2780-CP), were submitted for isobaric tagging for relative and absolute quantification (iTRAQ®) differential expression analysis. Briefly, each of the eight secretomes were trypsin-digested and labeled with one of eight iTRAQ® 8-plex reagents and subsequently submitted for either two-dimensional capillary liquid chromatography direct data dependent peptide tandem mass spectrometry on an Orbitrap Velos system or one-dimensional mass spectrometry analysis. RESULTS: 456 proteins were identified with the one-dimensional analysis with 2 distinct peptides. 2069 distinct differentially expressed proteins were identified in the two dimensional analysis. Initial relative differential expression rate comparisons of control cell lines, FT-194, FT-190 and 1816-575 versus ovarian cancer subtype and therapy-associated cell lines, HEY, TOV1946, TOV21G, A2780S and A2780CP, are promising. Four proteins were increased greater than three-fold across all ovarian cancer cell lines compared to normal fallopian tube and ovarian surface epithelial control cell lines: stromelysin-1, pigment epithelium-derived factor, matrix metalloproteinase-9 and receptor expression-enhancing protein 6. Large scale inferential statistical methodology will be used to differentiate cell lines. Citation Format: Yaling Zhou PhD, Daniel Brooks, PhD, Sumana Dey PhD, LeeAnn Higgins, PhD, Todd Markowski, BSc, Chad Hamilton MD, Robin Howard, MA, Sorana Raiciulescu MSc, Amy Skubitz PhD, John D. Andersen DO. DIFFERENTIAL PROTEIN EXPRESSION ANALYSIS OF SV40–IMMORTALIZED OVARIAN SURFACE, SV40–IMMORTALIZED FALLOPIAN TUBE AND OVARIAN CANCER SUBTYPE CELL LINE SECRETOMES BY ITRAQ® [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr DPOC-003.

Evaluation of the antitumor activity of NOV202, a novel microtubule targeting and vascular disrupting agent.

PurposeOverall, ~65% of patients diagnosed with advanced ovarian cancer (OC) will relapse after primary surgery and adjuvant first-line platinum- and taxane-based chemotherapy. Significant improvements in the treatment of OC are expected from the development of novel compounds having combined cytotoxic and antiangiogenic properties that make them effective on refractory tumors.MethodsPermeability of NOV202 was determined with Caco-2 monolayer assay. The compound’s pharmacokinetic profile and plasma:brain distribution were assessed in male C57Bl/6 mice. The compound’s impacts on tubulin, microtubules and cell cycle were investigated by using in vitro tubulin polymerization assay, cell-based immunofluorescence and live cell microscopy. The IC50 concentrations of NOV202 were assessed in a panel of eight cancer cell lines. Impact of the compound on vascular tube formation was determined using the StemKit and Chick chorioallantoic membrane assays. The in vivo efficacy of the compound was analyzed with an OC xenograft mouse model.ResultsNOV202 was found to suppress cancer cell proliferation at low nanomolar concentrations (IC50 2.3–12.0 nM) and showed equal efficacy between OC cell line A2780 (IC50 2.4 nM) and its multidrug-resistant subline A2780/Adr (IC50 2.3 nM). Mechanistically, NOV202 targeted tubulin polymerization in vitro in a dose-dependent manner and in cells induced an M phase arrest. In vivo, NOV202 caused a dose-dependent reduction of tumor mass in an A2780 xenograft model, which at the highest dose (40 mg/kg) was comparable to the effect of paclitaxel (24 mg/kg). Interestingly, NOV202 exhibited vascular disrupting properties that were similar to the effects of Combretastatin A4.ConclusionNOV202 is a novel tubulin and vascular targeting agent that shows strong anticancer efficacy in cells and OC xenograft models. The finding that the compound induced significantly more cell death in Pgp/MDR1 overexpressing OC cells compared to vincristine and paclitaxel warrants further development of the compound as a new therapy for OC patients with treatment refractory tumors and/or relapsing disease.

PGRMC1-dependent autophagy by hyperoside induces apoptosis and sensitizes ovarian cancer cells to cisplatin treatment

Cisplatin treatment some times leads to chemoresistance, which is now acknowledged partially due to the inductive expression of progesterone receptor membrane component (PGRMC)1 in ovarian cancer cells. PGRMC1 enhances autophagy, activates cytochrome p450, and inveigles signaling pathways to promote cell survival and reduce the effect of drug treatments. In this study, we give first line evidence that hyperoside inhibits cell viability, triggers autophagy and apoptosis in ovarian cancer cell lines. Mechanistically, PGRMC1-dependent autophagy was utilized by hyperoside to induce apoptotic cell death. Hyperoside induced the conversion of LC3B-I to LC3B-II and the formation of autophagosomes in ovarian cancer cells. Notably, PGRMC1 colocolized with LC3B‑II, and PGRMC1 overexpression enhanced hyperoside-induced autophagy and apoptosis, while PGRMC1 knockdown abrogated the action. Additionally, AKT signaling and Bcl-2 family were also involved in the hyperoside-induced autophagy and apoptosis. Importantly, in cisplatin-resistant ovarian cancer cells where PGRMC1 was overexpressed, hyperoside sensitized the cells to cisplatin treatment. Together these findings indicate hyperoside functions as a complementary therapy for ovarian cancer patients receiving platinum-based therapy.

Malignant ascites enhances migratory and invasive properties of ovarian cancer cells with membrane bound IL-6R in vitro

Transcoelomic route is the most common and the earliest route of metastasis, causing the ascites formation in advanced epithelial ovarian cancer (EOC). We demonstrated that interleukin 6 (IL-6) is enriched in the malignant ascites from patients with ovarian cancer, which enhanced invasive properties of EOC cells. Interestingly, the expression of IL-6R on cell membrane of EOC cells correlated with ascites-induced invasion. Selective knockdown of IL-6R or inhibition with IL-6 neutralizing antibody, suppressed the stimulatory effects of ascites on EOC invasion. Moreover, the ascites treatment induced the phosphorylation of JAK2-STAT3 and use of selective inhibitors of JAK2 and STAT3, blocked the expression of epithelial-mesenchymal transition related proteins in parallel with the suppression of EOC invasion. Thus, IL-6/IL-6R mediated JAK2-STAT3 signaling pathway could be a promising therapeutic target for anticancer therapy in ovarian cancer patients with ascites.

Abstract 1209: Istiratumab (MM-141), a bispecific antibody targeting IGF-1R and ErbB3, inhibits pro-survival signaling in vitro and potentiates the activity of standard of care chemotherapy in vivo in ovarian cancer models

Abstract Insulin-like growth factor receptor 1 (IGF-1R) signaling has been implicated in the pathogenesis of ovarian cancer. However, clinical trials evaluating monospecific IGF-1R inhibitors have demonstrated limited clinical efficacy. Our data indicate that ErbB3, a member of the ErbB receptor tyrosine kinase family, can activate pro-survival AKT signaling in response to IGF-1R blockade and may represent a potential escape route in the development of resistance to therapy. Istiratumab (MM-141), an IGF-1R and ErbB3 directed bispecific antibody, inhibits ligand activation of these signaling pathways and degrades IGF-1R and ErbB3 receptor-containing complexes, leading to inhibition of downstream pro-survival signaling. Here we tested the activity of istiratumab, alone and in combination with chemotherapy, in in vitro and in vivo models of ovarian cancer. Anti-proliferative activity of istiratumab monotherapy was evaluated in a panel of ovarian cancer cell lines in vitro. The effects of istiratumab and the ligands IGF-1 and heregulin on IGF-1R- and ErbB3-mediated survival signaling were tested by ELISA and immunoblotting. Co-treatment assays with istiratumab and chemotherapy investigated mechanisms of synergy and additivity. Anti-tumor activity of istiratumab, alone and in combination with chemotherapy, was tested in in vivo ovarian xenograft tumor models. Our results indicated that istiratumab monotherapy inhibits ovarian cancer cell line proliferation in vitro. In addition, istiratumab blocked ligand-mediated resistance to chemotherapy. Co-treatment of istiratumab, ligands or chemotherapy indicated a strong correlation between drug activity and IGF-1R expression. Furthermore, co-treatment of chemotherapies and ligands potentiated AKT activation, which was inhibited by istiratumab. In vivo studies showed that istiratumab potentiates the activity of chemotherapy in ovarian xenograft tumor models. Our findings demonstrate that co-inhibition of IGF-1R and ErbB3 signaling with istiratumab can potentiate standard of care chemotherapies in ovarian tumor models and warrant further investigation of istiratumab as a potential therapy for ovarian cancer patients. Citation Format: Michael D. Curley, Gege Tan, Isabel Yannatos, Adam Camblin, Sergio Iadevaia, Chrystal Louis, Alexey Lugovskoy. Istiratumab (MM-141), a bispecific antibody targeting IGF-1R and ErbB3, inhibits pro-survival signaling in vitro and potentiates the activity of standard of care chemotherapy in vivo in ovarian cancer models. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1209.

Abstract C53: Homologous recombination deficiency (HRD) of high grade serous ovarian tumors from the NOVA Phase III clinical study

Abstract Background: Genome-wide analysis was conducted on tumors obtained from patients enrolled in the NOVA study, a Phase 3 clinical trial evaluating the PARP inhibitor niraparib as a maintenance treatment in patients with platinum-sensitive ovarian cancer. Homologous recombination deficiency (HRD) and mutations in DNA damage repair genes were evaluated. Material and methods: DNA was extracted from formalin-fixed paraffin-embedded (FFPE) tumor tissue and used to create libraries that were hybridized to a custom Agilent SureSelect capture array carrying probes for 54,091 single nucleotide polymorphism sites distributed across the human genome, as well as probes targeting 43 genes involved in DNA repair, including BRCA1 and BRCA2. The captured and enriched DNA was sequenced on an Illumina HiSeq 2500 sequencer. Sequences covering SNP positions were used to generate allelic imbalance profiles. Measures of genomic instability, including determination of an HRD score (integer value of 0-100), were calculated using allelic imbalance profiles and determination of loss of heterozygosity (LOH) by allele-specific copy number (ASCN). A previously identified HRD threshold score of 42 was used to define HRD positivity in the absence of a BRCA mutation. Results: The NOVA study is a Phase 3, multicenter, randomized, double-blind, placebo-controlled study of niraparib as maintenance therapy in ovarian cancer patients who have either gBRCAmut or a tumor with high-grade serous histology and who have responded to their most recent chemotherapy containing a platinum agent. Tumor BRCA mutational status, HRD score and genomic sequencing of 43 DNA repair genes were obtained from tumor samples from both gBRCAmut and non-gBRCAmut cohorts. In the gBRCAmut cohort, HRD analysis of the tumor confirmed the presence of a deleterious or suspected deleterious mutation in all cases. In addition, an HRD score ≥ 42 and the presence of a deleterious mutation in TP53 with loss of heterozygosity (LOH) were observed in nearly all tumors. In the non-gBRCA cohort, somatic BRCA mutations were observed in approximately 13% of tumors, and approximately half of tumors with no evidence of a BRCA mutation had a high HRD score. In both cohorts, the use of three scoring algorithms (LOH, telomeric allelic imbalance [TAI], large-scale state transitions [LST]), was more predictive of BRCA mutational status than LOH alone. Additional genomic sequencing identified deleterious mutations with LOH in DNA repair genes, such as BRIP1, CDK12, RAD51C, PTEN, and RAD51D, with many tumors exhibiting multiple deleterious mutations. Conclusions: High grade serous ovarian cancer is characterized by a high degree of genomic instability. Genomic analysis in the clinical setting is able to identify patients with both germline and somatic BRCA mutations, in addition to BRCAwt tumors with other genetic defects that may be sensitive to agents exploiting deficiencies in HR. Citation Format: Keith Wilcoxen, Christopher Neff, Victor Abkevich, Joshua Timothy Jones, Kathryn Kolquist, Michael Mirza, Jerry Lanchbury, Keith Mikule, Shefali Agarwal, Anne-Renee Hartman, Alexander Gutin, Kirsten Timms. Homologous recombination deficiency (HRD) of high grade serous ovarian tumors from the NOVA Phase III clinical study. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C53.

High response rates to neoadjuvant platinum-based therapy in ovarian cancer patients carrying germ-line BRCA mutation

Preoperative therapy provides an advantage for clinical drug assessment, as it involves yet untreated patients and facilitates access to the post-treatment biological material. Testing for Slavic founder BRCA mutations was performed for 225 ovarian cancer (OC) patients, who were treated by platinum-based neoadjuvant therapy. 34 BRCA1 and 1 BRCA2 mutation carriers were identified. Complete clinical response was documented in 12/35 (34%) mutation carriers and 8/190 (4%) non-carriers (P = 0.000002). Histopathologic response was observed in 16/35 (46%) women with the germ-line mutation versus 42/169 (25%) patients with the wild-type genotype (P = 0.02). Somatic loss of heterozygosity (LOH) for the remaining wild-type BRCA1 allele was detected only in 7/24 (29%) post-neoadjuvant therapy residual tumor tissues as compared to 9/11 (82%) BRCA1-associated OC, which were not exposed to systemic treatment before the surgery (P = 0.009). Furthermore, comparison of pre- and post-treatment tumor material obtained from the same patients revealed restoration of BRCA1 heterozygosity in 2 out of 3 sample pairs presenting with LOH at diagnosis. The obtained data confirm high sensitivity of BRCA-driven OC to platinating agents and provide evidence for a rapid selection of tumor cell clones without LOH during the course of therapy.

Abstract POSTER-THER-1411: MM-141, an IGF-1R and ErbB3 directed tetravalent bispecific antibody, inhibits ovarian cancer cell growth in vitro

Abstract PURPOSE OF STUDY: Insulin-like growth factor receptor 1 (IGF-1R) signaling has been implicated in the pathogenesis of ovarian cancer. However, IGF-1R inhibitors have had limited efficacy in clinical trials to date. ErbB3, a member of the ErbB receptor tyrosine kinase family, can activate AKT survival signaling through binding of its ligand heregulin (HRG) in a majority of IGF-1 sensitive human cancer cell lines. ErbB3 and pAKT expression are upregulated following IGF-1R blockade and thus activated ErbB3 signaling may represent a potential escape route in the development of resistance to therapy. MM-141, an IGF-1R and ErbB3 directed bispecific antibody, blocks and degrades IGF-1R and ErbB3 containing receptor complexes leading to inhibition of downstream tumor pro-survival signaling to a greater extent as compared to anti-IGF-1R and ErbB3 antibodies. Here we explore the activity of MM-141 in ovarian cancer cell lines in vitro. EXPERIMENTAL PROCEDURES: Growth inhibitory activity of MM-141 was tested on a panel of established ovarian cancer cell lines in vitro. The ability of MM-141 to inhibit basal and IGF-1- and HRG-induced signaling was explored by ELISA and western blotting analyses. DATA SUMMARY: Inhibition of cell proliferation mediated by MM-141 varied among the ovarian cancer cell lines profiled in vitro. Furthermore, MM-141 treatment inhibited basal and ligand-activated IGF-1R, ErbB3 and downstream signaling in a selection of these ovarian cell lines. CONCLUSIONS: Our findings suggest that co-inhibition of IGF-1R and ErbB3 signaling with MM-141 has the potential to be an effective therapy for ovarian cancer patients by blocking redundant survival pathway activation. Citation Format: Michael Curley, Akos Czibere, Alexey Lugovskoy. MM-141, an IGF-1R and ErbB3 directed tetravalent bispecific antibody, inhibits ovarian cancer cell growth in vitro [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-THER-1411.

Abstract POSTER-THER-1417: Citral is the major component of ginger-derived terpenes to mediate p53-dependent apoptosis in cancer cells

Abstract Ginger extracts and ginger powder have been previously studied for their anti-cancer effects. It is generally believed that phenolic compounds present in ginger- especially shogaol and gingerol- are the active components that are cytotoxic to cancer cells. In our previous work we demonstrated that steam distilled extracts of ginger that are primarily composed of terpenes and do not contain any phenolic compounds, can induce cancer cell death with a potency that is significantly higher than gingerol and shogaol. In the current study we conduct a thorough analysis of the steam distilled extract of ginger to identify the bioactive terpene that induces cell death in ovarian cancer cells and also describe the molecular mechanisms leading to apoptosis. First, we screened the major components present in the extract for their ability to induce cancer cell death and determined that terpenes such as α-pinene and camphene are not active in the cell death assays. Instead, the major killing of ovarian and other cancer cells is mediated by the two monoterpene isomers, neral and geranial. Citral is a mixture of neral and geranial and is commercially available. Using citral in our assays we now demonstrate that these isomers can increase the expression of cleaved caspase 3 and apoptosis is also indicated in annexin V labeling assays. Treatment of cancer cells with citral results in a rapid rise in intracellular reactive oxygen species (ROS). In fact, inhibition of ROS by N-acetylcysteine blocks the ability of citral to produce apoptotic cell death. Another major observation is that citral induces rapid phosphorylation of the serine-15 residue of the tumor suppressor p53. Inhibition of ROS attenuates citral-induced phosphorylation of p53. Inhibition of p53 by pifithrin-α, a specific inhibitor, inhibits citral-mediated apoptosis. These experiments indicate that citral triggers ROS in cancer cells causing double stranded DNA breaks. DNA damage activates p53-mediated apoptotic signaling. Indeed, in cancer cells lacking p53 (SKOV3), while the ginger-derived terpene decreases proliferation, apoptosis is not observed. Instead after treatment with citral, SKOV3 cells undergo autophagy as determined by an increase in autophagolysosomes and increased expression of LC3B. We have also studied the mechanisms behind ROS increase in citral-treated cancer cells. Our studies show that immediately after exposure of cancer cells to citral, there is a rapid decrease in the intracellular levels of glutathione. This decrease is likely caused due to the enzymatic as well as non-enzymatic covalent coupling of glutathione and citral. As a result, citral works as a glutathione sink whereby the cancer cells are unable to control ROS. Concluding from these studies, we are using established concepts from medicinal chemistry to develop drug conjugates of citral that have higher bioavailability and can be targeted specifically to ovarian tumors. Even though p53 is mutated in ovarian tumors, not all mutations result in complete loss of function. We are screening for p53 mutations that result in only partial loss of tumor suppressor function. Patients stratified for such mutations will be good candidates for citral-based therapy. Citral has been approved by FDA as a safe food additive and hence can likely serve as an agent for maintenance therapy in ovarian cancer patients. Citation Format: Arvinder Kapur, Mildred Felder, Lucas Faas, Manish S. Patankar. Citral is the major component of ginger-derived terpenes to mediate p53-dependent apoptosis in cancer cells [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-THER-1417.