Citations

Study ObjectiveTo develop and validate a predictive model for glucose change and risk for new‐onset impaired fasting glucose in hypertensive participants following treatment with atenolol or hydrochlorothiazide (HCTZ).DesignRandomized multicenter clinical trial.PatientsA total of 735 white or African‐American men and women with uncomplicated hypertension.Measurements and Main ResultsPharmacogenomic Evaluation of Antihypertensive Responses (PEAR) is a randomized clinical trial to assess the genetic and nongenetic predictors of blood pressure response and adverse metabolic effects following treatment with atenolol or HCTZ. To develop and validate predictive models for glucose change, PEAR participants were randomly divided into a derivation cohort of 367 and a validation cohort of 368. Linear and logistic regression modeling were used to build models of drug‐associated glucose change and impaired fasting glucose (IFG), respectively, in the derivation cohorts. These models were then evaluated in the validation cohorts. For glucose change after atenolol or HCTZ treatment, baseline glucose was a significant (p<0.0001) predictor, explaining 13% of the variability in glucose change after atenolol and 12% of the variability in glucose change after HCTZ. Baseline glucose was also the strongest and most consistent predictor (p<0.0001) for development of IFG after atenolol or HCTZ monotherapy. The area under the receiver operating curve was 0.77 for IFG after atenolol and 0.71 after HCTZ treatment, respectively.ConclusionBaseline glucose is the primary predictor of atenolol or HCTZ‐associated glucose increase and development of IFG after treatment with either drug.

Abstract Purpose: The therapeutic potential of PARP inhibitors is predicted to extend beyond BRCA mutant phenotypes to homologous recombination (HR)-deficient cancers. Response of individual ovarian cancers to niraparib was characterized using treatment naïve, patient-derived tumorgraft models and correlated with predicted HR status and gene expression profile. Methods: Utilizing a living tumor bank of patient-derived ovarian xenografts (PDXs), niraparib (MK-4827) was evaluated in five high-grade ovarian cancer tumorgrafts (PDX077, PDX087, PDX039, PDX080 and PDX95) as monotherapy, combination with carboplatin ± paclitaxel and maintenance therapy. Intraperitoneal tumorgrafts were monitored for tumor growth with twice-weekly transabdominal ultrasound imaging. In vivo response to niraparib was correlated to massively parallel sequencing data (BROCA) for HR genes and with each source patient's platinum response. Tumorgrafts were accordingly classified into predicted HR-proficient and HR-deficient phenotypes. PARP1 and poly(ADP-ribose) polymer (pADPr) expression as well as gene expression by DNA microarray were compared between treatment and control tumor replicates, and HR-deficient vs. HR-proficient tumors. Results: PDX077 (verified to harbor a somatic BRCA2 mutation (predicted HR deficient)) and PDX039 without any HR mutations detected by BROCA (predicted HR proficient) both responded to niraparib monotherapy and combination therapy in vivo (p=0.002 and 0.009 for treated vs. control groups, respectively). Significant growth attenuation, but not regression, in response to single agent treatment was demonstrated in PDX080 (CDK12 mutation; predicted HR-deficient; p=0.02 vs. control). In comparison, a BRCA2-mutant model (PDX095) failed to respond to niraparib monotherapy (p=0.97). As predicted, niraparib was not active as a single agent or in combination with chemotherapy in a BRCA wild-type, predicted HR-proficient tumorgraft (PDX087; p=not significant). Niraparib enhanced tumor regression with carboplatin but not with paclitaxel/carboplatin in an HR-deficient tumorgraft (PDX077), and maintenance niraparib therapy was effective in prolonging recurrence-free survival. pADPr inhibition was demonstrated in all niraparib-treated tumorgrafts, while PARP1 degrada-tion was evident in tumorgrafts responsive to single agent niraparib. Differential gene expression was seen in niraparib treated vs. control tumors in HR-deficient tumorgrafts in comparison to HR-proficient tumors at the end of 4 weeks of treatment. Clustering of 6 most/least differentially expressed genes was predictive of response to niraparib. Furthermore, RAD51C and PTEN gene expression were diminished in PDX039 (HR proficient by BROCA; niraparib responsive), suggesting a possible mechanism for its sensitivity to niraparib. Conclusion: Response to niraparib was seen in both BRCA-mutant and BRCA-wildtype xenografts. Thus, BRCA or HR gene mutational status alone was not sufficient to predict response to niraparib. Low RAD51C, PTEN and loss of PARP1 expression following treatment were most characteristic of tumors responding to niraparib. Paclitaxel may be detrimental to the sensitizing effects of PARP inhibition on carboplatin, which may have clinical implications for the incorporation of PARP inhibitors in front-line treatment. Our data are supportive of the phase III study of niraparib as maintenance therapy in patients with platinum-sensitive ovarian cancer. This abstract is also presented as Poster A30. Citation Format: Mariam Al Hilli, S. John Weroha, Marc Becker, Xiaonan Hou, Sean Harrington, Sarah McKinstrey, Kimberly Kalli, Karin Goodman, Keith Wilcoxen, Elizabeth Swisher, Scott Kaufmann, Paul Haluska. In vivo antitumor activity of the PARP inhibitor niraparib (MK-4827) in homologous recombination deficient and proficient ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr PR05.

Abstract Purpose: Ovarian cancer has a high recurrence and mortality rate. A barrier to improved outcomes includes a lack of accurate models for preclinical testing of novel therapeutics. Experimental Design: Clinically relevant, patient-derived tumorgraft models were generated from sequential patients and the first 168 engrafted models are described. Fresh ovarian, primary peritoneal, and fallopian tube carcinomas were collected at the time of debulking surgery and injected intraperitoneally into severe combined immunodeficient mice. Results: Tumorgrafts demonstrated a 74% engraftment rate with microscopic fidelity of primary tumor characteristics. Low-passage tumorgrafts also showed comparable genomic aberrations with the corresponding primary tumor and exhibit gene set enrichment of multiple ovarian cancer molecular subtypes, similar to patient tumors. Importantly, each of these tumorgraft models is annotated with clinical data and for those that have been tested, response to platinum chemotherapy correlates with the source patient. Conclusions: Presented herein is the largest known living tumor bank of patient-derived, ovarian tumorgraft models that can be applied to the development of personalized cancer treatment. Clin Cancer Res; 20(5); 1288–97. ©2014 AACR.

Abstract Ovarian cancer mortality ranks highest among all gynecologic cancers with growth factor pathways playing an integral role in tumorigenesis, metastatic dissemination, and therapeutic resistance. The HER and VEGF receptor (VEGFR) are both overexpressed and/or aberrantly activated in subsets of ovarian tumors. While agents targeting either the HER or VEGF pathways alone have been investigated, the impact of these agents have not led to overall survival benefit in ovarian cancer. We tested the hypothesis that cotargeting HER and VEGFR would maximize antitumor efficacy at tolerable doses. To this end, ovarian cancer xenografts grown intraperitoneally in athymic nude mice were tested in response to AC480 (pan-HER inhibitor, “HERi”), cediranib (pan-VEGFR inhibitor “VEGFRi”), or BMS-690514 (combined HER/VEGFR inhibitor “EVRi”). EVRi was superior to both HERi and VEGFRi in terms of tumor growth, final tumor weight, and progression-free survival. Correlative tumor studies employing phosphoproteomic antibody arrays revealed distinct agent-specific alterations, with EVRi inducing the greatest overall effect on growth factor signaling. These data suggest that simultaneous inhibition of HER and VEGFR may benefit select subsets of ovarian cancer tumors. To this end, we derived a novel HER/VEGF signature that correlated with poor overall survival in high-grade, late stage, serous ovarian cancer patient tumors. Mol Cancer Ther; 12(12); 2909–16. ©2013 AACR.

Objective Genome-wide association studies have identified a large number of single nucleotide polymorphisms (SNPs) associated with a wide array of cancer sites. Several of these variants demonstrate associations with multiple cancers, suggesting pleiotropic effects and shared biological mechanisms across some cancers. We hypothesised that SNPs previously associated with other cancers may additionally be associated with colorectal cancer. In a large-scale study, we examined 171 SNPs previously associated with 18 different cancers for their associations with colorectal cancer. Design We examined 13 338 colorectal cancer cases and 40 967 controls from three consortia: Population Architecture using Genomics and Epidemiology (PAGE), Genetic Epidemiology of Colorectal Cancer (GECCO), and the Colon Cancer Family Registry (CCFR). Study-specific logistic regression results, adjusted for age, sex, principal components of genetic ancestry, and/or study specific factors (as relevant) were combined using fixed-effect meta-analyses to evaluate the association between each SNP and colorectal cancer risk. A Bonferroni-corrected p value of 2.92×10 −4 was used to determine statistical significance of the associations. Results Two correlated SNPs—rs10090154 and rs4242382—in Region 1 of chromosome 8q24, a prostate cancer susceptibility region, demonstrated statistically significant associations with colorectal cancer risk. The most significant association was observed with rs4242382 (meta-analysis OR=1.12; 95% CI 1.07 to 1.18; p=1.74×10 −5 ), which also demonstrated similar associations across racial/ethnic populations and anatomical sub-sites. Conclusions This is the first study to clearly demonstrate Region 1 of chromosome 8q24 as a susceptibility locus for colorectal cancer; thus, adding colorectal cancer to the list of cancer sites linked to this particular multicancer risk region at 8q24.

Abstract Despite advances in chemotherapeutic options over the last four decades, ovarian cancer remains the most lethal gynecologic malignancy with a cure rate that is essentially unchanged. A major barrier is lack of treatment-naïve, clinically- relevant in vivo models of epithelial ovarian cancer (EOC). To target this problem, we have developed low-passage in vivo models of EOC derived from patient primary debulking procedures at Mayo Clinic (Rochester, MN). Tumors were obtained from consented patients with suspected ovarian cancer, minced and injected into severe combined immunodeficiency (SCID) mice intraperitoneally for model establishment. To the date, we have heterotransplanted 129 EOC or ovarian malignant mixed mullerian (MMMT) tumors. The most common histologic subtype is serous (70.5%), followed by endometrioid (12.4%), clear cell (6.9%), and others (9.9%). The tumors were injected intraperitoneally into severe combined immunodeficiency (SCID) mice and the average time to moribund (TTM) was 174 +/− 83 days. In general, tumors grew faster with serial passages, TTM for epithelial tumors was 87 +/− 15 days and 19.5 +/− 3 days for MMMT. De novo ascites developed in 17 models and 24 models developed bowel metastasis, two clinically-relevant complications in late-stage ovarian cancer patients. Tumorgrafts were histologically similar to their source patient tumors and were positive for expression epithelial markers (pan-cytokeratin). The engraftment rate was 72.4% (n=87) after ≤ 6 months of lead-time, which is the average time to tumorgraft harvest. Passage of well-established tumorgrafts in SCID mice was successful in 88.6 % (n= 70) of all mice but only 56% (n=16) of athymic nude mice, consistent with prior studies demonstrating improved engraftment rates in more immunodeficient mice. Molecular characterization of tumorgrafts by array comparative genomic hybridization revealed similar gains and losses between the patient, early-passage, and later-passage tumorgraft tissues, indicating the tumorgrafts were genetically similar to their primary tumor. Analysis of tumorgrafts using the Affymetrix Human Plus 2.0 arrays revealed a predominance of previously described molecular subtypes C3, C4, and C5. Current investigations with both standard chemotherapy and novel targeted therapies are ongoing. Taken together, these models are as diverse as the patient population from which they are derived, produce clinically-relevant complications of EOC, maintain genetic fidelity in SCID mice, and are useful preclinical models for testing and development of novel therapeutics for ovarian cancer. High rates of engraftment are feasible. These tumorgrafts may help define predictors of response and eventually, lead to better treatments for patients. This work is funded by the Mayo Ovarian SPORE (CA136393) and the Minnesota Ovarian Cancer Alliance. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3274. doi:1538-7445.AM2012-3274

Abstract DNA double-strand breaks (DSBs) are highly cytotoxic lesions caused by genotoxin such as ionizing radiation (IR). Following DSB, cells activate the DNA-damage response pathway by activating protein kinases such as ATM, ATR and DNA-PK, which then trigger histone H2AX phosphorylation and the accumulation of proteins such as Mediator of DNA damage checkpoint protein 1 (MDC1), 53BP1, and BRCA1 into IR-induced foci. This process initiates the repair of DSB. Previously we have identified a novel biomarker for radiation response, Bora, by using a genome-wide association approach using data generated with 300 human lymphoblastoid cell liens. Bora is known as a cofactor of Aurora-A, which is involved in mitosis regulation. During G2, Aurora-A, in complex with Bora, phosphorylates Plk1 at Thr-210. Activated Plk1 phosphorylates Cdc25C and Wee1, which induces activation of cyclin B-cdk1 complexes and promotes mitotic entry. In this study, we want to determine the underlying mechanisms by which Bora regulates response to IR. We found that knockdown of Bora in human cancer cell lines including HupT3, MIAPaCa-2 and Hela (siBora) exhibit increased clonogenic survival rate in response to IR, an observation that is opposite from the effect of Plk1 knockdown, suggesting a different mechanism involved. Knockdown of Bora also desensitize cancer cells to chemotherapeutic agents including gemcitabine and oxiplatin. This enhanced resistance to genotoxin is primarily due to increased DNA DSB repair. More than 90% of DSBs were repaired in siBora cells compared with 60% in control cells 8 hours after cell exposure to 2 Gy IR. Upon IR, more cells with Bora knockdown retained in G2-M phase compared with control. Furthermore, Bora directly interacts with BRCT domain of MDC1 via its C terminus, and over expression of Bora can abolish MDC1 foci formation induced by IR. All of these observations suggested a role of Bora in DNA damage response pathway and in turn, in chemo-radio resistance. Indeed, overexpression of the full length or C-terminus of Bora sensitized cancer cells to IR treatment, while the N-terminal Bora did not have significant effect on IR response. In summary, we have identified a novel function of Bora involved in DNA damage and repair pathway, which indicates a broad role of Bora in both tumorgenesis and chemo-radio resistance. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2660. doi:10.1158/1538-7445.AM2011-2660

Abstract Background: In estrogen receptor positive (ER+) breast cancer human epidermal growth factor receptor 2 (HER2) expression is associated with resistance to tamoxifen (Tam). Endoxifen is the most abundant active metabolite of Tam, resulting in part from cytochrome P450 2D6 (CYP2D6) metabolism. While Tam has been extensively used to model proliferative ER/HER2 cross-talk, there are no published data regarding endoxifen's effect on ER/HER2 nongenomic nor ER genomic signaling. Methods: Using ER+ cells (MCF7) and ER+/HER2+ cells (MCF7-HER2, BT474) we compared the effects of Tam and endoxifen on proliferation using crystal violet assays, Erk1/2 phosphorylation by western blotting, and E2-stimulated ER-regulated gene expression of amphiregulin (AREG), c-Myc (MYC) and progesterone receptor (PGR) by real-time RT-PCR assays. To examine the anti-proliferative affects of endoxifen compared to Tam in vivo we performed E2-stimulated MCF7-HER2 xenograft studies in athymic nude mice. Endoxifen doses of 25 (low) and 75 mg/kg (high) were used based on our prior pharmacokinetic studies showing achievable steady state levels of 100 nM and 1 uM, respectively. Z-Endoxifen HCl was synthesized by NCI. Results: Endoxifen, unlike Tam, potently inhibits growth in both ER+ and ER+/HER2+ breast cancer cell lines at concentrations observed in human CYP2D6 intermediate and extensive metabolizers (&gt;40 nM). Tam (10-1000 nM) stimulates phosphorylation of Erk1/2 in stark contrast to endoxifen at similar doses. Endoxifen (100-1000 nM) significantly decreases E2-stimulated transcription of ER-regulated genes in MCF7-HER2 cells; AREG 2-3 fold, MYC 1-2 fold, and PGR 2-4 fold. Conversely, Tam (10-1000 nM) maintains or stimulates transcription; AREG 2-3 fold, MYC 0.5-2.5 fold, and PGR 0-3 fold. After 7 weeks of treatment of MCF7-HER2 xenografts, both high (p=0.001) and low dose endoxifen (p=0.01) resulted in greater antitumor activity than Tam, with high dose superior to low dose endoxifen (p=0.024). MCF7-HER2 xenografts that progressed on Tam to 200% growth at 7 weeks were randomized to either continued Tam or endoxifen. Four weeks after randomization endoxifen was superior to Tam (p&lt;0.0001) with tumor size decreased by ≥ 20%. No significant toxicity was observed.Conclusions: We have demonstrated in both ER+ and ER+/HER2+ breast cancer cell lines that in contrast to Tam, endoxifen potently inhibits growth (both in vitro and in vivo), does not activate Erk1/2 signaling, and inhibits E2-stimulated transcription of ER-regulated genes. Endoxifen exhibited potent antitumor activity in MCF7-HER2 xenografts refractory to Tam. These data support the ongoing NCI sponsored phase I studies of Z-endoxifen at Mayo Clinic and NCI. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2283. doi:10.1158/1538-7445.AM2011-2283

Abstract Background: First in human studies of Z-endoxifen hydrochloride (E), the active metabolite of tamoxifen (T), are underway in metastatic breast cancer (BC). Previous data have demonstrated the superiority of aromatase inhibitors (AI's) over T in estrogen receptor (ER) + BC. Using an in vivo aromatase expressing model (MCF7/AC1), we compared the antitumor activity of E with T and Letrozole (L), as well as the antitumor activity and global gene expression changes of E with T in an L-resistant model. Methods: MCF7/AC1 tumors were stimulated with androstenedione. Once tumor size reached 300 mm3, mice (30/group) were randomly assigned to one of five treatment groups: control (daily, po), T (500 μg/day, sc), endoxifen 25 mg/kg/day p.o.(LDE) endoxifen 75 mg/kg/day p.o. (HDE) or letrozole, 10 μg/day s.c for 4 weeks. Tumors were harvested from control, T, and E groups while the L group continued treatment until the development of resistance defined as an increase in tumor volume of at least 300% from day 1. Mice with L-resistant tumors were randomly assigned to T (n=4) or E (n=5) for 4 weeks and then sacrificed. Gene expression in L-resistant tumors was quantified using Affymetrix U133+2 and changes in gene expression profiles [comparing T and E with L-resistant (n=3)] were analyzed. Genes identified as significantly different were confirmed by real-time RT-PCR assays. Results: At the 4 week time point, both doses of E and L resulted in greater anti-tumor activity than control (Wilcoxon rank sum test: all p &lt; 0.0001); however, tumor burden did not differ between T and control (p=0.095). HDE resulted in significantly less tumor burden than T (p=0.002) but was similar to L. In mice that continued on L, resistance developed at 24 weeks in 9/25 mice. These mice were randomly assigned to either T (n=4) or E (n=5) for 4 weeks. Tumor volume (expressed as a% of its size prior to randomization) was significantly different comparing E (73.3%; range: 69.3 to 80.75%) versus T (148.39%; range: 114.07 to 165.99%) (Wilcoxon rank sum test p=0.016). Compared to control, microarray studies identified 1518 unique probe sets regulated by E (p&lt;0.001) compared to 441 for T including estrogen-regulated genes such as progesterone receptor (PGR) and amphiregulin (AREG) that were significantly down-regulated in the E group [PGR (−6.2 fold, p=0.000008) and AREG (−3.2 fold, p=.0006) but unchanged or up-regulated in the T group (PGR unchanged and AREG +9.2 fold p=0.00002). These findings were confirmed by RT-PCR. Conclusions: Using the MCF7/AC1 model previously used to show the superiority of AI's over T, HDE demonstrated similar antitumor activity to L and was superior to T. In cells resistant to L, E was superior to T and gene expression changes demonstrate that E down-regulates while T activates estrogen regulated genes. These findings support the ongoing development of E for the treatment of ER+ BC. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD01-06.