Phase II trial of bevacizumab and sorafenib in recurrent ovarian cancer patients with or without prior-bevacizumab treatment.

OBJECTIVE: To examine whether blocking multiple points of the angiogenesis pathway by addition of sorafenib, a multi-kinase inhibitor against VEGFR2/3, Raf, c-Kit, and PDGFR, to bevacizumab would yield clinical activity in ovarian cancer (OvCa). METHODS: This phase II study tested bevacizumab plus sorafenib in two cohorts; bevacizumab-naïve and bevacizumab-exposed patients. Bevacizumab (5 mg/kg IV every 2 weeks) was given with sorafenib 200 mg bid 5 days-on/2 days-off. The primary objective was response rate using a Simon two-stage optimal design. Progression-free survival (PFS) and toxicity were the secondary endpoints. Exploratory correlative studies included plasma cytokine concentrations, tissue proteomics and dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI). RESULTS: Between March 2007 and August 2012, 54 women were enrolled, 41 bevacizumab-naive and 13 bevacizumab-prior, with median 5 (2-9) and 6 (5-9) prior systemic therapies, respectively. Nine of 35 (26%) evaluable bevacizumab-naive patients attained partial responses (PR), and 18 had stable disease (SD) ≥ 4 months. No responses were seen in the bevacizumab-prior group and 7 (54%) patients had SD ≥ 4 months, including one exceptional responder with SD of 27 months. The overall median PFS was 5.5 months (95%CI: 4.0-6.8 months). Treatment-related grade 3/4 adverse events (≥5%) included hypertension (17/54 [31%]; grade 3 in 16 patients and grade 4 in one patient) and venous thrombosis or pulmonary embolism (5/54 [9%]; grade 3 in 4 patients and grade 4 in one patient). Pretreatment low IL8 concentration was associated with PFS ≥ 4 months (p = .031). CONCLUSIONS: The bevacizumab and sorafenib combination did not meet the pre-specified primary endpoint although some clinical activity was seen in heavily-pretreated bevacizumab-naive OvCa patients with platinum-resistant disease. Anticipated class toxicities required close monitoring and dose modifications.

Phase I/Ib study of olaparib and carboplatin in heavily pretreated recurrent high-grade serous ovarian cancer at low genetic risk.

Purpose: To investigate maximum tolerated dose (MTD), activity and predictive biomarkers of olaparib with carboplatin in BRCA wild-type (BRCAwt) high grade serous ovarian carcinoma (HGSOC) patients. Methods: A 3+3 dose escalation study examined olaparib capsules (400 mg twice daily [BID], days 1-7) with carboplatin (AUC3-5 on day 1) every 21 days for 8 cycles, followed by olaparib 400 mg BID maintenance. Blood and tumor biopsy samples were collected pre- and on-treatment in the expansion cohort for PAR levels and proteomic endpoints. Results: 30 patients (median 7 prior regimens [2-12], 63% (19/30) platinum-resistant) were enrolled. Dose-limiting toxicity was thrombocytopenia/neutropenia, and infection with carboplatin AUC5 (2/6 patients). MTD was olaparib 400 mg BID + carboplatin AUC4. Grade 3/4 adverse events (>10%) included neutropenia (23%), thrombocytopenia (20%), and anemia (13%). Five of 25 (20%) evaluable patients had partial response (PR; median 4.5 months [3.3-9.5]). Clinical benefit rate (PR + stable disease ≥4 months) was 64% (16/25). A greater decrease in tissue PAR levels was seen in the clinical benefit group versus no benefit (median normalized linear change -1.84 [-3.39- -0.28] vs 0.51 [-0.27- 1.29], p = 0.001) and a DNA repair score by proteomics did not correlate with response. Conclusions: The olaparib and carboplatin combination is tolerable and has clinical benefit in subsets of heavily pretreated BRCAwt HGSOC, independent of platinum sensitivity.

Phase I/Ib study of olaparib and carboplatin in women with triple negative breast cancer.

PURPOSE: To investigate the safety, activity, and potential biomarkers of response to olaparib and carboplatin combination in sporadic triple negative breast cancer (TNBC). EXPERIMENTAL DESIGN: Metastatic or recurrent TNBC patients with no germline BRCA mutation or with BRCAPro scores <10% and a negative family history were eligible. A 3+3 dose escalation tested olaparib capsules (400mg bid, days1-7) with carboplatin AUC3-5 on day1 or 2 every 21 days, ≤ 8 cycles, with olaparib 400mg bid maintenance. Peripheral blood mononuclear cells were collected for polymorphisms and PAR levels, and paired tumor biopsies (pre-/post-cycle 1) for proteomics and apoptosis endpoints. RESULTS: 28 women were treated (median 5 prior regimens [0-12]). Dose-limiting toxicity was thrombocytopenia, and symptomatic hyponatremia with carboplatin AUC5. The maximum tolerated dose was olaparib 400mg bid+carboplatin AUC4. Grade 3 and 4 adverse events included neutropenia (36%), thrombocytopenia (11%), and anemia (11%). Responses included 1 complete response (CR; 69+months) and 5/27 partial responses (19%; median 4months [4-7]), for a response rate of 22%. Biomarker findings did not correlate with response. The long-term CR patient with prior negative BRCA testing was found to have deletion of BRCA1 exons1-2. CONCLUSIONS: The olaparib/carboplatin combination is tolerable and has modest activity in sporadic TNBC patients. Further evaluation of predictive biomarkers to identify those with BRCA wild type who had response is warranted.

Prexasertib, a cell cycle checkpoint kinases 1 and 2 inhibitor, increases in vitro toxicity of PARP inhibition by preventing Rad51 foci formation in BRCA wild type high-grade serous ovarian cancer.

PARP inhibitors (PARPi) have been effective in high-grade serous ovarian cancer (HGSOC), although clinical activity is limited against BRCA wild type HGSOC. The nearly universal loss of normal p53 regulation in HGSOCs causes dysfunction in the G1/S checkpoint, making tumor cells reliant on Chk1-mediated G2/M cell cycle arrest for DNA repair. Therefore, Chk1 is a reasonable target for a combination strategy with PARPi in treating BRCA wild type HGSOC. Here we investigated the combination of prexasertib mesylate monohydrate (LY2606368), a Chk1 and Chk2 inhibitor, and a PARP inhibitor, olaparib, in HGSOC cell lines (OVCAR3, OV90, PEO1 and PEO4) using clinically attainable concentrations. Our findings showed combination treatment synergistically decreased cell viability in all cell lines and induced greater DNA damage and apoptosis than the control and/or monotherapies (p<0.05). Treatment with olaparib in BRCA wild type HGSOC cells caused formation of Rad51 foci, whereas the combination treatment with prexasertib inhibited transnuclear localization of Rad51, a key protein in homologous recombination repair. Overall, our data provide evidence that prexasertib and olaparib combination resulted in synergistic cytotoxic effects against BRCA wild type HGSOC cells through reduced Rad51 foci formation and greater induction of apoptosis. This may be a novel therapeutic strategy for HGSOC.

Sequence-Specific Pharmacokinetic and Pharmacodynamic Phase I/Ib Study of Olaparib Tablets and Carboplatin in Women's Cancer.

Purpose: Our preclinical studies showed that the PARP inhibitor, olaparib, prior to carboplatin attenuated carboplatin cytotoxicity. We evaluated sequence-specific pharmacokinetic and pharmacodynamic effects, safety, and activity of the combination.Experimental Design: Eligible patients had metastatic or recurrent women's cancer. Olaparib tablets were introduced (100 or 200 mg twice daily, days 1-7) in a 3 + 3 dose escalation with carboplatin AUC4 or 5 every 21 days, up to eight cycles, followed by olaparib 300 mg twice daily maintenance. Patients were randomly assigned to starting schedule: cohort A (olaparib days 1-7, carboplatin on day 8) or B (carboplatin on day 1, olaparib days 2-8) during cycle 1. Patients received the reversed scheme in cycle 2. Blood was collected for olaparib pharmacokinetics, platinum-DNA adducts, comet assay, and PAR concentrations. The primary objectives were to examine schedule-dependent effects on olaparib pharmacokinetics and platinum-DNA adducts.Results: A total of 77 (60 ovarian, 14 breast, and 3 uterine cancer) patients were treated. Dose-limiting toxicity was thrombocytopenia and neutropenia, defining olaparib 200 mg twice daily + carboplatin AUC4 as the MTD. Olaparib clearance was increased approximately 50% when carboplatin was given 24 hours before olaparib. In vitro experiments demonstrated carboplatin preexposure increased olaparib clearance due to intracellular olaparib uptake. Quantities of platinum-DNA adducts were not different as a function of the order of drug administration. Responses included 2 CRs and 31 PRs (46%) with a higher RR in BRCA mutation carriers compared with nonmutation carriers (68% vs. 19%).Conclusions: Tablet olaparib with carboplatin is a safe and active combination. Carboplatin preexposure causes intracellular olaparib accumulation reducing bioavailable olaparib, suggesting carboplatin should be administered prior to olaparib. Clin Cancer Res; 23(6); 1397-406. ©2016 AACR.

Development of a multiparameter flow cytometric assay as a potential biomarker for homologous recombination deficiency in women with high-grade serous ovarian cancer.

OBJECTIVES: PARP inhibitors (PARPi) are a novel class of drugs with activity in patients with acquired or germline homologous recombination (HR) deficiency-associated high-grade serous ovarian cancer (HGSOC). We hypothesized that measuring γH2AX as an indicator of DNA double-strand breaks (DSB), and MRE11 or RAD51 as an indicator of DSB repair, would reflect HR status and predict response to PARPi-based therapy. Our aim was to develop and use high-throughput multiparametric flow cytometry to quantify γH2AX with MRE11 or RAD51 in PBMCs as a readily available surrogate. METHODS: Healthy donor PBMCs were used for assay development and optimization. We validated induction of γH2AX, MRE11 and RAD51 by staining with fluorophore-conjugated antibodies. The multiparameter flow cytometric method was applied to PBMC samples from recurrent HGSOC patients who were treated with PARPi, olaparib and carboplatin. RESULTS: Stimulation was necessary for quantification of a DNA damage response to olaparib/carboplatin in healthy donor PBMCs. The flow cytometric protocol could not distinguish between cytoplasmic and nuclear RAD51, erroneously indicating activation in response to injury. Thus, MRE11 was selected as the marker of DSB repair. PBMCs from 15 recurrent HGSOC patients were then examined. Patients who did not respond to PARPi therapy had a significantly higher pre-treatment level of γH2AX (p = 0.01), and a higher ratio of γH2AX/MRE11 (11.0 [3.5-13.2] v. 3.3 [2.8-9.9], p < 0.03) compared with responders. CONCLUSIONS: We successfully developed and applied a multiparameter flow cytometry assay to measure γH2AX and MRE11 in PBMCs. Prospective studies will be required to validate this surrogate biomarker assay as a potential predictive biomarker of PARPi-based therapy.

CECs and IL-8 Have Prognostic and Predictive Utility in Patients with Recurrent Platinum-Sensitive Ovarian Cancer: Biomarker Correlates from the Randomized Phase-2 Trial of Olaparib and Cediranib Compared with Olaparib in Recurrent Platinum-Sensitive Ovarian Cancer.

OBJECTIVE: Olaparib (O), a polyADPribose polymerase (PARP) inhibitor, and cediranib (C), a VEGF receptor (VEGFR)1-3 inhibitor together had greater activity than O alone in women with recurrent platinum-sensitive ovarian cancer (OvCa). The objective of this study is to identify potential lead biomarker candidates for response to O + C in the setting of a multi-institutional phase II study of O with and without C in recurrent platinum-sensitive OvCa. METHODS: A self-selected group of patients participated in a prospectively planned exploratory biomarker substudy of the randomized phase II study of O versus O + C. Whole blood for peripheral blood mononuclear cell (PBMC) and plasma isolation was collected prior to and on day 3 of treatment. Quantitation of circulating endothelial cells (CEC), IL-6, IL-8, VEGF, and soluble VEGFR-2 plasma concentrations, and polyADPribose (PAR) incorporation were performed. Single nucleotide polymorphism analysis of XRCC1 280H, R194W, and Q399R was done. Dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI) was performed at baseline and day 3 of treatment. Parameter changes were compared between the two arms using an exact Wilcoxon rank sum test. Kaplan-Meier and log-rank tests were used to examine survival outcome. RESULTS: Thirteen patients elected to participate in the translational substudy, seven patients on O and six patients on O + C. Patients on O + C had a greater decrease in IL-8 concentration and larger CEC fold increase compared with those on O alone (p = 0.026, p = 0.032). The fold increase in CEC on day 3 was associated with duration of progression-free survival (PFS) (R (2) = 0.77, 95% CI 0.55-0.97, p < 0.001). IL-8 post-pretreatment changes correlate with PFS (p = 0.028). XRCC1 DNA polymorphisms were not related to PFS. All patients had reduction in PAR incorporation, and all except one had reduction in vascular flow on DCE-MRI. CONCLUSION: Our exploratory correlative studies indicate that CEC and IL-8 changes may be predictive for response to O + C and prognostic in recurrent platinum-sensitive OvCa, requiring prospective validation.

Phase I/Ib study of olaparib and carboplatin in BRCA1 or BRCA2 mutation-associated breast or ovarian cancer with biomarker analyses.

BACKGROUND: Olaparib has single-agent activity against breast/ovarian cancer (BrCa/OvCa) in germline BRCA1 or BRCA2 mutation carriers (gBRCAm). We hypothesized addition of olaparib to carboplatin can be administered safely and yield preliminary clinical activity. METHODS: Eligible patients had measurable or evaluable disease, gBRCAm, and good end-organ function. A 3 + 3 dose escalation tested daily oral capsule olaparib (100 or 200mg every 12 hours; dose level1 or 2) with carboplatin area under the curve (AUC) on day 8 (AUC3 day 8), then every 21 days. For dose levels 3 to 6, patients were given olaparib days 1 to 7 at 200 and 400 mg every 12 hours, with carboplatin AUC3 to 5 on day 1 or 2 every 21 days; a maximum of eight combination cycles were permitted, after which daily maintenance of olaparib 400mg every12 hours continued until progression. Dose-limiting toxicity was defined in the first two cycles. Peripheral blood mononuclear cells were collected for polymorphism analysis and polyADP-ribose incorporation. Paired tumor biopsies (before/after cycle 1) were obtained for biomarker proteomics and apoptosis endpoints. RESULTS: Forty-five women (37 OvCa/8 BrCa) were treated. Dose-limiting toxicity was not reached on the intermittent schedule. Expansion proceeded with olaparib 400mg every 12 hours on days 1 to 7/carboplatin AUC5. Grade 3/4 adverse events included neutropenia (42.2%), thrombocytopenia (20.0%), and anemia (15.6%). Responses included 1 complete response (1 BrCa; 23 months) and 21 partial responses (50.0%; 15 OvCa; 6 BrCa; median = 16 [4 to >45] in OvCa and 10 [6 to >40] months in BrCa). Proteomic analysis suggests high pretreatment pS209-eIF4E and FOXO3a correlated with duration of response (two-sided P < .001; Pearson's R (2) = 0.94). CONCLUSIONS: Olaparib capsules 400mg every 12 hours on days 1 to 7/carboplatin AUC5 is safe and has activity in gBRCAm BrCa/OvCa patients. Exploratory translational studies indicate pretreatment tissue FOXO3a expression may be predictive for response to therapy, requiring prospective validation.

Translational predictive biomarker analysis of the phase 1b sorafenib and bevacizumab study expansion cohort.

Predictive biomarkers are needed to triage patients to the best therapy. We prospectively planned examination of sequential blood, biopsy, and functional imaging with which to confirm the mechanism and to identify potential predictive biomarkers in a phase Ib clinical trial expansion of patients with solid tumors receiving sorafenib/bevacizumab. The maximally tolerated doses of sorafenib at 200 mg twice daily with bevacizumab at 5 mg/kg every other week were given to biopsiable patients. Patients were randomized to receive either sorafenib or bevacizumab monotherapy for the first 28-day cycle with the second drug added with cycle 2. Biopsies, dynamic contrast-enhanced MRI, and fluorodeoxyglucose-proton emission tomography were done pre-therapy and at 2 and 6 weeks (2 weeks into combination therapy). Tumor and serum proteomics, Ras/Raf mutational analysis, and functional imaging results were examined individually and across the dataset to identify potential changes predictive of response to therapy and those that confirm the biochemical drug mechanism(s). Therapy with sorafenib/bevacizumab resulted in clinical benefit in 45% of this mixed solid tumor group. ERK activation and microvessel density were decreased with monotherapy treatment with sorafenib or bevacizumab, respectively; whereas a decreased signal over the group of total AKT, phospho(p)-VEGF receptor2, p-endothelial nitric-oxide synthase, b-RAF, and cleaved poly(ADP-ribose) polymerase was associated with earlier progression of disease. Tumor metabolic activity decreased in those patients with clinical benefits lasting longer than 4 months, and activity increased with progression of disease. Cleavage of caspase 3 and poly(ADP-ribose) polymerase was increased, and Ki67 expression decreased in patients with prolonged clinical benefits, consistent with decreased proliferation and increased apoptosis. The conglomerate analysis, incorporating pharmacodynamic and tumor biochemistry, demonstrated sorafenib/bevacizumab-targeted vascular activity in the tumor. Results suggest potential biomarkers for which changes, as a group, during early therapeutic exposure may predict clinical benefit.

Feasibility and safety of sequential research-related tumor core biopsies in clinical trials.

BACKGROUND: There has been increasing interest in serial research biopsies in studies of targeted therapies. Definition of patient characteristics and optimal target tissue for safe research tumor biopsy in the era of antiangiogenic and targeted agents is needed. METHODS: This institutional review board-approved, retrospective study included chart and interventional radiology case review from 6 phase 1/2 studies at the National Cancer Institute. RESULTS: One hundred forty-two of 150 protocol patients who were approached gave consent for research biopsies. Patients' median age was 56 years (range, 27-78 years), their median body mass index was 25.8 kg/m(2) (range, 14.4-46.2 kg/m(2) ), they had an Eastern Cooperative Oncology Group performance status of 0 or 1, and they had normal end-organ function. Baseline biopsies were collected from 138 of 142 patients (97%), and paired specimens were collected from 96 (70%). Most patients had metastatic gynecologic cancers (85%), and 78% had target disease below the diaphragm with a median size of 2.7 cm (range, 1-14.5 cm). Protocol therapies included kinase inhibitors (35%), angiogenesis inhibitors (54%), and olaparib/carboplatin (11%); therapy was not interrupted for biopsies. All adverse events were uncomplicated and were observed in 4 patients (liver subcapsular hematoma in 1 patient, vasovagal syncope in 2 patients, and pneumothorax in 1 patient). The complication rate in obese patients was similar to that in nonobese patients (3 of 108 patients vs 1 of 34 patients, respectively). Sixty-seven patients (48%) were receiving bevacizumab at the time of subsequent biopsies. The complication rate was not different between patients who were and were not receiving bevacizumab (3 of 67 patients vs 1 of 71 patients, respectively). Ninety-five percent of biopsies yielded useable material. CONCLUSIONS: Serial percutaneous core-needle biopsies can be obtained safely and yield material applicable for multiple translational applications. Obesity and/or concomitant antiangiogenic therapy and depth of disease did not increase the risk or preclude the successful acquisition of useful tissue.

L-asparaginase inhibits invasive and angiogenic activity and induces autophagy in ovarian cancer.

Recent work identified L-asparaginase (L-ASP) as a putative therapeutic target for ovarian cancer. We suggest that L-ASP, a dysregulator of glycosylation, would interrupt the local microenvironment, affecting the ovarian cancer cell-endothelial cell interaction and thus angiogenesis without cytotoxic effects. Ovarian cancer cell lines and human microvascular endothelial cells (HMVEC) were exposed to L-ASP at physiologically attainable concentrations and subjected to analyses of endothelial tube formation, invasion, adhesion and the assessment of sialylated proteins involved in matrix-associated and heterotypic cell adhesion. Marked reduction in HMVEC tube formation in vitro, HMVEC and ovarian cancer cell invasion, and heterotypic cell-cell and cell-matrix adhesion was observed (P < 0.05-0.0001). These effects were associated with reduced binding to ß1integrin, activation of FAK, and cell surface sialyl Lewis(X) (sLe(x)) expression. No reduction in HMVEC E-selectin expression was seen consistent with the unidirectional inhibitory actions observed. L-ASP concentrations were non-toxic to either ovarian cancer or HMVEC lines in the time frame of the assays. However, early changes of autophagy were observed in both cell types with induction of ATG12, beclin-1, and cleavage of LC-3, indicating cell injury did occur. These data and the known mechanism of action of L-ASP on glycosylation of nascent proteins suggest that L-ASP reduces of ovarian cancer dissemination and progression through modification of its microenvironment. The reduction of ovarian cancer cell surface sLe(x) inhibits interaction with HMVEC and thus HMVEC differentiation into tubes, inhibits interaction with the local matrix reducing invasive behaviour, and causes cell injury initiating autophagy in tumour and vascular cells.

Adhesion molecule protein signature in ovarian cancer effusions is prognostic of patient outcome.

BACKGROUND: Ovarian cancer cells in malignant effusions lack attachment to solid-phase matrix substrata and receive survival stimuli through cell-cell and cell-soluble matrix molecule interactions. We hypothesized that adhesion-related survival and proliferation pathway signals can inform clinical outcomes and guide targeted therapeutics. METHODS: Lysed cell pellets from a blinded set of benign (n = 20) and malignant (n = 51) peritoneal and pleural ovarian cancer patient effusions were applied to reverse-phase protein arrays and examined using validated antibodies to adhesion-associated protein endpoints. Results were subjected to hierarchical clustering for signature development. Association between specimen type, protein expression, and clinicopathologic associations were analyzed using the Mann-Whitney U test. Survival outcomes were estimated using the Kaplan-Meier method with log-rank comparison. RESULTS: A cell adhesion protein signature obtained from unsupervised clustering distinguished malignant from benign effusions (P = 6.18E-06). Protein subset analyses from malignant cases defined 3 cell adhesion protein clusters driven by E-cadherin, epithelial cell adhesion molecule, and N-cadherin, respectively. The components of the E- and N-cadherin clusters correlated with clinical outcome by Kaplan-Meier statistics. Univariate analysis indicated that FAK and phosphorylated AKT were associated with higher overall and progression-free survival (PFS) (P = .03), and Akt, phosphorylated paxillin, and E- and N-cadherin were associated with improved PFS (P ≤ .05). If 4 or 5 of the index adhesion proteins were high, PFS was improved by multivariate analysis (P ≤ .01). CONCLUSIONS: This hypothesis-testing examination of tumor cell adhesion molecules and pathways yielded potential predictive biomarkers with which to triage patients to selected molecular therapeutics and may serve as a platform for biomarker-based stratification for clinical application.

Progranulin is a potential prognostic biomarker in advanced epithelial ovarian cancers.

OBJECTIVE: There are few validated relapse prediction biomarkers for epithelial ovarian cancer (EOC). We have shown progranulin (PGRN) and secretory leukocyte protease inhibitor (SLPI) are up regulated, overexpressed survival factors in EOC. We hypothesized they would predict presence of occult EOC. METHOD: PGRN, SLPI, and the known biomarker HE4 were measured in EOC patient plasma samples, prospectively collected every 3 months from initial remission until relapse. Clinical data and CA125 results were incorporated into statistical analyses. Exploratory Kaplan-Meier estimates, dividing markers at median values, evaluated association with progression-free survival (PFS) and overall survival (OS). Area-under-the-curve (AUC) statistics were computed from receiver operating characteristic (ROC) curves to evaluate discrimination ability. A Cox proportional hazards model assessed the association between PFS, OS, and biomarkers, adjusting for clinical prognostic factors. RESULTS: Samples from 23 advanced stage EOC patients were evaluated. PGRN at 3 months was the only biomarker independently associated with PFS (P<0.0001) and OS (P<0.003). When used to predict progression by 18 months, sensitivity and specificity were 93% and 100%, respectively, with AUC=0.944. The Cox model hazard ratio for PFS, divided at 59 ng/ml by ROC analysis and adjusted for clinical factors, was 23.5 (95% CI: 2.49-220). Combinations with SLPI, HE4, and/or CA125 did not improve the model. CONCLUSIONS: We report pilot data indicating a potential independent association of PGRN on EOC patient PFS and OS. A validation study will be required to confirm this finding and to inform whether PGRN warrants evaluation as a potential screening biomarker.

Vandetanib, designed to inhibit VEGFR2 and EGFR signaling, had no clinical activity as monotherapy for recurrent ovarian cancer and no detectable modulation of VEGFR2.

PURPOSE: To evaluate clinical activity and target modulation of vandetanib in women with recurrent ovarian cancer. EXPERIMENTAL DESIGN: A phase II trial of orally administered vandetanib 300 mg daily was designed to include analyses of target inhibition through paired biopsies and dynamic imaging. Core 18-gauge needle biopsies and dynamic contrast-enhanced magnetic resonance imaging were obtained before initiation of therapy and 6 weeks into therapy. Biopsy samples were subjected to reverse-phase protein lysate array endpoint analysis. Cytokine concentrations were measured by enzyme-linked immunosorbent assay in serially collected plasma samples. RESULTS: Twelve patients entered the study, and accrual was terminated in the first stage because of lack of response or disease stabilization beyond 6 months. Adverse events included rash, diarrhea, and prolonged QT interval corrected for heart rate, but not hypertension. Exploratory analyses showed that epidermal growth factor receptor (EGFR) phosphorylation was reduced in the eight paired biopsy sets obtained; vascular endothelial growth factor (VEGF) receptor-2 phosphorylation was not consistently affected nor were dynamic contrast-enhanced MRI permeability and flow parameters. Serial plasma VEGF concentrations were variable and did not significantly change in the 11 patients assessed. CONCLUSIONS: Vandetanib 300 mg daily monotherapy had no significant clinical benefit in this disease setting. Proteomic analysis of paired biopsies detected both phosphorylated-EGFR and phosphorylated-VEGF receptor-2 in ovarian tumor tissue, but only phosphorylated-EGFR was measurably inhibited by vandetanib.

Constitution and quantity of lysis buffer alters outcome of reverse phase protein microarrays.

Application of novel technology to clinical samples requires optimization of procedures. Reverse phase protein lysate arrays use femtomolar quantities of tissue lysate from clinical samples with which to profile biochemical events happening in the tumor. We analyzed the effects of different tissue solubilization buffers on frozen ovarian tumor samples in order to identify the system with the best signal intensity dynamic range, reproducibility, tissue solubility, and signal consistency. A modified RIPA-like buffer supplemented with DTT and SDS was deemed optimal.

Gene expression profiling in the mammary gland of rats treated with 7,12-dimethylbenz[a]anthracene.

Identification of molecular markers of early-stage breast cancer development is important for the diagnosis and prevention of the disease. In the present study, we used microarray analysis to examine the differential expression of genes in the rat mammary gland soon after treatment with a known chemical carcinogen, 7,12-dimethylbenz[a]anthracene (DMBA), and prior to tumor development. Six weeks after DMBA, differential expression of multiple genes involved in cell growth, differentiation and microtubule dynamics were observed. Gene expression changes were further validated by a combination of techniques, including real-time PCR, RT-PCR, Western blotting and immunohistochemistry. An inhibition of differentiation in this early stage was suggested by the lower expression of beta-casein and transferrin and higher expression of hsp27 in glands from DMBA-treated rats. Possible cell cycle deregulation was indicated by an increased expression of cyclin D1 and hsp86, a heat shock protein associated with cyclin D1. Prior to tumor development, DMBA increased cellular proliferation as detected by Ki-67 and stathmin immunostaining in histologically normal mammary gland. Genes regulating microtubule function, including stathmin, Ran, alpha-tubulin and hsp27, were all overexpressed in the mammary gland of DMBA-treated rats, raising the possibility that disruption of microtubule dynamics and abnormal mitosis may be critical events preceding breast cancer development. Several of the altered proteins, including hsp27, hsp86 and stathmin, may ultimately serve as markers of early breast cancer development.

Global gene expression profiling of chemically induced rat mammary gland carcinomas and adenomas.

Chemical carcinogens induce both benign and malignant mammary gland tumors in female Sprague-Dawley rats. To identify gene expression profiles associated with malignancy, cDNA microarray analysis was used to compare gene expression profiles in rat mammary gland carcinomas, adenomas, and normal mammary gland. Tumors were induced with various chemical carcinogens including 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 7-12-dimethylbenz[a]anthracene (DMBA), N-nitrosomethylurea (NMU), and 4-aminobiphenyl. The global gene expression profiles in carcinomas and adenomas were distinguishable by hierarchical clustering and multi-dimensional scaling analyses. Permutation analysis revealed 110 clones statistically differentially expressed between benign and malignant tumors (p < 0.0005). Carcinomas showed relatively high expression of several genes associated with mammary epithelial cell growth and proliferation (e.g., cyclin D1, PDGFalpha) and relatively low expression of differentiation marker genes (e.g., beta -casein, whey acidic protein, transferrin). Other categories of genes showing differential expression between carcinomas and adenomas were associated with protein homeostasis, cytoskeleton, extracellular matrix, and cell metabolism (fatty acid metabolism, oxidative phosphorylation, and glycolysis). Major gene families implicated in malignancy by over-expression in carcinomas included the annexins (annexin A1 and A4) and Stat family of transcription factors (Stat3 and Stat5a). The elevated expression of the prolactin receptor in carcinomas concomitant with several components of the mitogenic prolactin signaling pathway implicated prolactin/prolactin receptor/Stat5a/cyclin D1 in rat mammary gland malignancy.

Steroid hormone receptor expression and proliferation in rat mammary gland carcinomas induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a mammary gland carcinogen present in the human diet. Herein, the expression of estrogen receptor alpha (ERalpha), estrogen receptor beta (ER beta) and progesterone receptor (PR) was examined in mammary gland carcinomas induced by PhIP in female Sprague-Dawley rats. Quantitative real-time polymerase chain reaction demonstrated that ER alpha, ER beta and PR were statistically elevated by 3-, 4- and 8-fold in carcinomas compared with normal mammary glands. By immunohistochemistry, carcinomas showed statistically higher nuclear expression of all three steroid receptors with the majority of carcinomas showing at least 10% of epithelial cells stained for ER alpha (49/55, 89%), ER beta (41/55, 75%) and PR (48/55, 87%). Furthermore, the level of expression of the three steroid hormone receptors was positively correlated with each other across the bank of carcinomas (Spearman analysis, P < 0.05). The expression of ER alpha in carcinomas was associated with tumor grade, extent of nuclear pleomorphism and cellular proliferation as measured by proliferating cell nuclear antigen (PCNA) and phospho-Rb immunostaining (Spearman analysis, P < 0.05). Confocal microscopy was used to measure the percentage of epithelial cells showing nuclear colocalization of receptors, PCNA, and cyclin D1. Colocalization of the receptors, and the colocalization of the receptors with PCNA and cyclin D1 was strikingly higher in carcinomas than in the normal mammary gland. In carcinoma cells, 37% of ER alpha positive epithelial cells were colocalized with PCNA in contrast to just 0.25% of cells in the normal mammary gland. The findings from this study indicate that ER alpha, ER beta and PR were co-upregulated and nuclear localized in epithelial cells from rat mammary carcinomas compared with normal mammary glands, and that the co-upregulation was positively correlated with proliferation and cell cycle progression in carcinomas.

Gene expression profiling of chemically induced rat mammary gland cancer.

Exposure to carcinogens through diet, the atmosphere and other means is generally regarded as influencing human cancer risk, but the impact of specific environmental carcinogens on human breast cancer incidence is still unknown. We examined whether distinct chemical carcinogens induce a unique transcriptional profile in mammary gland cancer that is characteristic of the etiologic agent. Rat mammary gland cancers (n = 34) were generated by various carcinogens, including the food-derived heterocyclic amines 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 7,12-dimethylbenz[a]anthracene, N-nitrosomethylurea and 4-aminobiphenyl. The histopathology of the carcinomas was graded using a modified Scarff-Bloom-Richardson scheme and the gene expression profiles in the carcinomas were evaluated on a 10K cDNA microarray. Unsupervised hierarchical clustering analysis revealed two major clusters of carcinomas irrespective of the carcinogenic agent that distinguished two groups with different histopathological parameters (degree of differentiation, nuclear grade, mitotic activity, epithelial cell growth pattern and necrosis). Using class comparison analysis and hierarchical clustering of all carcinomas irrespective of histopathology, gene expression profiles were further shown to be statistically differentially expressed according to the carcinogenic agent. These findings indicate that the transcriptional program in carcinomas is unique to the etiologic agent and can be observed among a diverse set of carcinogens despite variations in carcinoma histopathology. The ability to use microarray analysis to discern an etiology-specific profile among a pathologically heterogeneous group of breast carcinomas may ultimately be valuable in determining the role of environmental chemical carcinogens in human breast cancer risk.

Possible role of Stat5a in rat mammary gland carcinogenesis.

Signal transducer and activator of transcription (Stat) 5a is a transcription factor mediating the action of specific cytokines, growth factors and hormones on gene expression. In the mammary gland, Stat5a is well recognized for its function in prolactin signaling, lobuloalveolar development, and milk protein expression during pregnancy and lactation. Latent cytoplasmic Stat5a is activated by tyrosine phosphorylation and following dimerization undergoes nuclear import. In the current study, Stat5a expression was examined immunohistochemically in carcinomas induced by the chemical carcinogens 7,12-dimethylbenz[a]anthracene and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine. A high percentage of carcinomas showed nuclear labeling of Stat5a [44 of 68 (65%)] with Stat5a nuclear labeling index ranging from 18 to 77%. In contrast, control normal mammary gland tissue displayed cytosolic expression. Carcinomas with different Stat5a staining patterns (cytoplasmic or nuclear) showed a statistical difference for the proliferating cell nuclear antigen (PCNA) labeling, tumor differentiation, nuclear grade, mitotic activity, and tumor size. High Stat5a nuclear expression was closely correlated with the higher-grade carcinomas. Stat5a nuclear expression was also detected in intraductal proliferations (10 of 21 lesions) and in ductal carcinomas in situ (13 of 15 lesions). Immunohistochemical analysis was further carried out in human breast cancers. Stat5a nuclear expression was detected in ductal and lobular carcinomas and DCIS at a frequency of 48% (15/31), 33% (2/6), and 40% (2/5), respectively. Nuclear expression of Stat5a in human breast cancers also correlated with the PCNA nuclear labeling index. The findings implicate activated Stat5a in mammary gland cancer development in the rat and human.