bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2669: Early-phase trials in patients with advanced gallbladder cancer and cholangiocarcinoma: The MD Anderson Clinical Center for Targeted Therapy experience
Authors: Subbiah Ishwaria M. , Tsimberidou Apostolia M. , Naing Aung , Subbiah Vivek , Kaseb Ahmed O. , Falchook Gerald S. , Fu Siqing , Hong David S. , Piha-Paul Sarina A. , Wheler Jennifer J. , Janku Filip , Kurzrock Razelle
Published: August 2012

BACKGROUND: Patients with cholangiocarcinoma (CC) and gallbladder carcinoma (GC) have few effective therapeutic options in the relapsed and/or metastatic setting. With that purpose, we analyzed the characteristics and outcomes of patients with advanced CC and GC treated on early-phase clinical trials in the Clinical Center for Targeted Therapy at MD Anderson Cancer Center. METHODS: We searched an electronic database of consecutive pts with GC and CC referred to the Clinical Center for Targeted Therapy starting in November 2004. We assessed the relationship between types of clinical trial and pts’ tumor types, progression-free survival, and mutations. RESULTS: Of the 72 patients with CC and GC referred to the clinic, 32 (44%) were not enrolled in a clinical trials mainly due to deterioration of performance status (n=25), decision to pursue alternate therapies (n=6), and insurance denial (n=1). Forty pts (5 w GC; 35 w CC) who received treatment on early clinical trials are included in this analysis. The median age was 60.2 yrs (range, 41.4-73.6 yrs). ECOG performance status (PS) was 0-1 in 36 pts (90%) and 2 in 4 (10%). Median number of prior therapies was 3 (range 0-17). Six pts were not restaged due to early disease progression. Of the 40 pts evaluable for response, 8 (20%) had stable disease (SD) > 6 months and 3 (8%) had a partial response (PR) (total SD > 6 mos/PR = 28%). Highest rates of SD > 6 mos/PR were observed in patients treated with protocols that included hepatic arterial infusion drug administration (7/17 = 41%) or anti-angiogenic agents (9/24 = 38%) (with 6 of these pts receiving treatment that included hepatic arterial infusion chemotherapy combined with a systemic anti-angiogenic agent). SD lasting 9 months was also seen in 1 pt treated with a MEK inhibitor. Median progression-free survival for the 40 pts was 2.0 months 9 (95% CI 1.7, 2.8) on early-phase clinical trials versus 3.0 months on their last FDA-approved treatment before Phase I referral (95% CI 2.3, 3.7). CONCLUSIONS: About one-third of patients with CC and GC referred for early-phase trials cannot be enrolled because of poor performance status. Twenty-eight percent of patients who met eligibility criteria achieved SD > 6 mos/PR, with responses predominantly observed in regimens that contained locoregional treatment, anti-angiogenic agents, or a targeted MEK inhibitor.

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 2669. doi:1538-7445.AM2012-2669
Abstract 2671: CYP2D6 polymorphisms are not associated with tamoxifen outcome in premenopausal women with ER positive breast cancer of the POSH cohort
Authors: Saladores Pilar H. , Schroth Werner , Eccles Diana , Tapper William , Gerty Sue , Brauch Hiltrud B.
Published: August 2012

Long-term adjuvant tamoxifen therapy for five years is the anti-estrogenic standard of care for ER-positive breast cancer in premenopausal patients. The metabolic activation of tamoxifen into the active metabolite endoxifen is mediated by Cytochrome P450 (CYP) 2D6 and it has been shown that CYP2D6 polymorphims can influence the clinical outcome of postmenopausal breast cancer patients (Schroth et al. JAMA 2009, Mürdter et al.CPT 2011). While this is currently still under debate awaiting the denouement (Brauch et al. JCO 2011), no such relationship has been investigated for premenopausal patients. We used the Prospective Study of Outcomes in Sporadic versus Hereditary Breast Cancer (POSH) collection to explore the pharmacogenetic relationship between CYP2D6 polymorphisms and tamoxifen outcome in premenopausal patients. POSH is an observational cohort study established to explore the effect of genetic factors on breast cancer prognosis (Eccles et al. BMC Cancer 2007). We genotyped genomic DNA of 772 patients with adjuvant tamoxifen (age 18 to 41 years) for CYP2D6 and other CYP enzymes by MALDI TOF-MS. Patients were assigned for CYP2D6 metabolizer status, poor (PM), intermediate (IM), and extensive (EM), and tested for clinical associations using Kaplan-Meier and Cox regression analyses. After a median follow-up of 4 years (0.1 - 8 years) with 24.6% of study participants reporting a relapse, Kaplan Meier survival analysis did not show an association between CYP2D6 metabolizer status and the occurrence of relapse. In contrast, CYP3A5 functional status predicted by the *1 genotype was associated with worse outcome compared to the CYP3A5 deficient status (*3). Since chemotherapy is a suggested confounder of the CYP2D6 tamoxifen pharmacogenetic effect and the majority of POSH patients had received chemotherapy prior to tamoxifen, there is a possibility that variation in the metabolism and cytotoxic effects of these agents may mask CYP2D6 dependent tamoxifen outcome. However, in premenopausal patients due to higher plasma estrogen concentrations, the inhibition of tumor ER signaling may likely depend on factors other than endoxifen formation. While this is currently being explored with respect to the underlying ER pharmacodynamic effects, the polymorphic CYP3A5, one of the major drug metabolizing enzymes, appears to be a candidate marker for the prognosis of premenopausal breast cancer.

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 2671. doi:1538-7445.AM2012-2671
Abstract 2677: Determination of the optimal route of administration of Salmonella typhimurium A1-R to target breast cancer in nude mice
Authors: Zhang Yong , Suetsugu Atsushi , Zhang Nan , Zhang Lei , Hoffman Robert M. , Zhao Ming
Published: August 2012

We have previously developed the genetically-modified strain Salmonella typhimurium A1-R that selectively targets tumors. S. typhimurium A1-R is auxotrophic for leu and arg, which precludes it from growing in normal tissues but allows high tumor virulence. We report here the efficacy and safety of three different routes of S. typhimurium A1-R delivery oral (p.o.), intravenous (i.v.), and intra-tumor (i.t.) in nude mice with orthotopic human breast cancer. Nude mice with MDA-MB-435 human breast cancer expressing red fluorescence protein (RFP) were administered S. typhimurium A1-R by either of 3 routes: (p.o.: 2 × 108 CFU/200 αl; i.v.: 2.5 × 107 CFU/100 αl; i.t.: 2.5 × 107 CFU/50 µl) twice a week. Tumor growth was monitored by florescence imaging and caliper measurement in two dimensions. Treatment with S. typhimurium A1-R via all three routes resulted in effective targeting and tumor growth inhibition. Efficacy was observed earliest in the animals treated by i.v. injection. GFP-expressing S. typhimurium A1-R were imaged to target, colonize, and replicate in the human breast tumor, liver, and spleen as observed by fluorescence imaging. Bacterial colonization of tumor and normal organs at different time points were determined after S. typhimurium delivery by either of the 3 routes. S. typhimurium A1-R targeted tumors at much higher levels than normal organs with all 3 routes of administration. The bacteria replicated and survived longer in the tumor than normal organs with all 3 routes of administration. Two weeks after bacteria administration by all 3 routes, the bacteria disappeared from normal organs, but grew continuously in the tumor. The fewest bacteria were detected in normal organs after oral administration, which suggests oral administration has the highest safety. The i.v. route had the greatest anti-tumor efficacy. There were no obvious toxic effects on the host with any of the routes of administration. Non-tumor-bearing mice tolerated S. typhimurium A1-R, p.o., twice weekly treatment and could survive as long as untreated mice. The results of this study suggest that oral administration was the most safe to the host and the i.v. route was most effective for tumor targeting with S. typhimurium A1-R.

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 2677. doi:1538-7445.AM2012-2677
Abstract 2681: Multicolor imageable orthotopic tumorgraft models of human patient pancreatic cancer
Authors: Suetsugu Atsushi , Katz Matthew H.G. , Fleming Jason B. , Hassanein Mohamed K. , Moriwaki Hisataka , Bouvet Michael , Saji Shigetoyo , Hoffman Robert M.
Published: August 2012

In order to help develop more effective treatment for pancreatic cancer, we developed a multicolor imageable orthotopic mouse model for individual human pancreatic-cancer patients. Pancreatic cancer patient tumor specimens were initially established in SCID-NOD mice. The tumors were then passaged orthotopically into transgenic nude mice expressing GFP in almost every tissue. Both the primary tumors and resultant metastasis acquired GFP stroma and could be imaged by GFP fluorescence. GFP stroma included cancer-associated fibroblasts (CAFs). Further passage to nude mice expressing RFP in almost all tissues resulted in tumors and metastasis acquiring RFP stroma in addition to their GFP stroma, including CAFs. Further passage to transgenic nude mice expressing CFP in almost all tissues resulted in tumors and metastasis acquiring CFP stroma in addition to RFP and GFP stroma including CAFs. The model can be used to image primary and metastatic progression of patient pancreatic tumors, study acquisition of stroma and to test both standard and novel cancer- and stroma-targeting agents. The imageable tumor-graft model should prove valuable for treatment evaluation of individual cancer patients, as well as for evaluation of experimental therapeutics targets in the tumor or the tumor microenvironment such as cancer-associated fibroblasts (CAFs).

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 2681. doi:1538-7445.AM2012-2681
Abstract 2687: Imaging sub-cellular dynamics of proliferating intra- and extra-vascular cancer cells
Authors: Suetsugu Atsushi , Digman Michelle , Aguilar Jose A. , Jiang Ping , Hassanein Mohamed , Moriwaki Hisataka , Bouvet Michael , Saji Shigetoyo , Gratton Enrico , Hoffman Robert M.
Published: August 2012

In order to visualize nuclear-cytoplasmic dynamics during intravascular cancer cell-proliferation and extravasation, green fluorescent protein (GFP) was expressed in the cytoplasm of HT-1080 human fibrosarcoma cells, and red fluorescent protein (m-Cherry), linked to histone H2B, was expressed in the nucleus. Nuclear m-Cherry expression enabled visualization of nuclear dynamics, whereas simultaneous cytoplasmic GFP expression enabled visualization of nuclear-cytoplasmic ratios as well as simultaneous cell and nuclear shape changes. Thus, total cellular dynamics can be visualized in the living dual-color cells in real time. The cell cycle position of individual living cells was readily visualized by the nuclear-cytoplasmic ratio and nuclear morphology. Real-time induction of apoptosis was observed by nuclear size changes and progressive nuclear fragmentation. Intra- and extra-vascular mitotic cells were visualized by imaging after injection of the cancer cells in the epigastric cranials vein in an abdominal flap. After one hour, round and elongated cancer cells were observed in the vessel. Three hours after injection, invadopodia of the cancer cells was observed. Five hours after injection, dual-color cancer cells began to divide within the vessel. By 10 hours, some intra-vascular cancer cells underwent apoptosis. Deformed new blood vessels in the tumor were observed 10 days later. Extravascular cancer cells were dividing in the tumor at day 14. The subcellular in vivo imaging approach described here provides new visual targets for trafficking, extravasating and invading cancer cells.

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 2687. doi:1538-7445.AM2012-2687
Abstract 269: A novel mechanism of p21 induction by oxaliplatin in p53 deficient cancer cells
Authors: Xu Weiguo , Li Dawei
Published: August 2012

p21(CDKN1A) is a well known cyclin-dependent kinase (cdk) inhibitor. As a critical cell cycle checkpoint of p53 mediated DNA damage response, p21 interferes with cyclin-CDK2 complex, blocking cell cycle at the G1/S interface, thus reducing the risk of DNA damaged cells transforming to cancer cells. Activation of p21 checkpoint by therapeutic agent is often associated with cancer cell cycle arrest and effective tumor suppression. However, many cancer lost wild type p53 while p21 in these cells maintains at a low level. In these cells p21 transcription is mainly controlled by p53-independent mechanisms through various cis-acting elements and these type of cancer are often more likely to resist chemo treatment. In search of effective therapeutic agents against p53 negative and drug resistant cancers we used SKOV3, a p53 deficient cancer cell line, to assess the ability of common therapeutic drugs to induce p21 expression. Promoter-reporter assays suggest p21 promoter is significantly stimulated by Oxaliplatin in SKOV3 cells compared with most common drugs used in chemotherapy. Through the promoter deletion analysis we identified a previously unreported Oxaliplatin responsive cis-acting element located between −237 to −220bp in the p21 promoter. Genomic DNA functional element analysis using ENCODE (Encyclopedia of DNA Elements) Consortium suggests that a vertebrate-conserved element overlaps well with the newly discovered Oxaliplatin responsive element. This conserved promoter element is required for the effective induction of p21 promoter activity by Oxaliplatin and such induction is positively related to drug induced S-phase cell cycle arrest. Finally, the ability of p21 induction of chemotherapy drugs is well correlated with their effectiveness of reducing SKOV3 xenograft tumors in nude mice.

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 269. doi:1538-7445.AM2012-269
Abstract 2690: Evaluation of the hemostatic status in patients with prostate cancer using thromboelastography and tissue factor- microparticles
Authors: Toukh Mazen , Black Angela , Siemens Robert D. , Othman Maha
Published: August 2012

Coagulopathy is reported as the second most common cause of death from cancers, particularly prostate cancer. DVT and pulmonary embolism are two major thrombotic complications in prostate cancer and the risk is even higher with chemotherapy and hormonal therapy. Thromboelastography (TEG) is a global hemeostatic test that detects and specifies the type of coagulopathy encountered through a vesicoelastic trace that reflects the kinetics of the clot from the initial fibrin thread till and fibrinolysis. We performed a hemostatic study in 27 patients (age range 59-88 years) diagnosed with prostate cancer at various stages (metastatic and non-metastatic) as compared to a control group (n=9) matching the same age range and with -ve pathology for prostate cancer. The study included whole blood TEG and flow cytometry analysis of microprticles (MPs) in plasma using Annexin V- FITC and anti-tissue factor - PE. Analysis of the data revealed hypercoagulable state in all patients except two who were maintained on coumadin as prophylaxis for previous DVT. Hypercoagulability was indicated by shorter R time, increased alpha angle, MA and clot index. The mean values for TEG parameters in the patients were: R: 6.01 vs 9.8 minutes in the control group, alpha angle: 68.3 vs 53.1 degrees in controls, MA: 69.3 vs 57.9 mm in controls, and CI: 3.32 vs 0.7 in controls. Paired student t test showed significant differences as regards R time (P=0.009), MA (p=0.053) and CI (P=0.051). Microparticle assay revealed significant elevation in the number of microparticles carrying tissue factor in the patient group compared to the control group (p=0.05). The mean plasma TF-MPs in patient group was 5,142 MPs/uL compared to 2,914 MPs/ uL in the control group suggesting a link between elevated tissue factor and hypercoagulability observed in these patients. To our knowledge, this is the first report for the use of TEG in patients with prostate cancer. TEG is a relatively simple test that uses a small volume of blood and can be a useful tool for evaluation of patients’ thrombotic potential and may help identification of those who may require anticoagulant prophylaxis.

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 2690. doi:1538-7445.AM2012-2690
Abstract 2691: A randomized Phase III study comparing the efficacy of Bacillus Calmette Guérin strain Tice versus Connaught for immunotherapy of non-muscle invasive bladder cancer
Authors: Rentsch Cyrill A. , Birkhäuser Frédéric , Studer Urs E. , Albert Matthew L. , Thalmann George N.
Published: August 2012

Introduction: For almost forty years now, adjuvant immunotherapy with intravesical Bacillus Calmette Guérin (BCG) is standard of care in the treatment of non-muscle invasive bladder cancer (NMIBC). The question whether the choice of the different available BCG strains used for treatment influences treatment outcome is still under debate. We report on a randomized phase III study comparing the two most commonly used strains in Europe and the USA. Patients and Methods: This study was performed under approval of the Cantonal Ethical Committee of Bern, Switzerland, to evaluate recurrence free survival in patients treated with BCG as the primary end-point. Between 1998 and 2010 149 patients (n=149) were recruited. Patients underwent transurethral resection of all visible bladder tumors or random bladder biopsies in case of a solely positive bladder wash cytology. TaG3 and T1G3 tumors underwent a second resection to confirm non-muscle invasive disease. Two to 15 days after surgery, patients were either randomized to receive six weekly intravesical instillations with 2-8x108 CFU OncoTice ® (BCG Tice) or 6.6-19.2 x108 CFU ImmuCyst ® (BCG Connaught) dissolved in 50 ml of saline according to manufacturers recommendations. Patients were followed in 3-monthly intervals for 3yrs, then in 6-monthly intervals by cystoscopy and bladder wash cytology. Relapses were confirmed by histology after transurethral surgery. Cox regression analysis and Log rank tests served for statistical analysis. Results: Gender, age, tumor stage and grade were well balanced between the two treatment arms (p=0.38). Median follow up was 25 months (range: 0.3-136). Side effects did not differ between the two treatment arms (p=0.42). Age and gender did not have an impact on treatment response (p=0.71). Five year recurrence-free survival for all patients was 61%. Patients treated with Connaught had significantly less recurrences than patients treated with OncoTice (p<0.002). Five year recurrence-free survival was 75% and 46% for Connaught and Tice treated patients, respectively. Median recurrence-free survival was 28 months (range: 0.6-136) for Connaught and 22 months (range: 0.3-122) for Tice treated patients. Progression-free and overall survivals were not significantly different between the two treatment arms. Conclusions: The choice of the BCG strain impacts on treatment outcome and favors the use of BCG Connaught over Tice in the treatment of NMIBC.

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 2691. doi:1538-7445.AM2012-2691
Abstract 2720: Sym004, a novel anti-EGFR antibody mixture augments radiation response in human lung and head and neck cancer models
Authors: Huang Shyhmin , Armstrong Eric A. , Kragh Michael , Pedersen Mikkel W. , Harari Paul M.
Published: August 2012

Sym004* is a newly developed EGFR targeting agent that is a mixture of two anti-EGFR antibodies directed against distinct epitopes on domain III of EGFR. In contrast to existing anti-EGFR antibodies, Sym004 induces rapid and efficient EGFR internalization and degradation. In the current study, we examine the capacity of Sym004 to augment radiation response in lung cancer and head and neck (H&N) cancer model systems. We examined the anti-proliferative effect of Sym004 confirming 40∼60% growth inhibition by Sym004 across a variety of lung and H&N cancer cell lines. Using clonogenic survival analysis, we identified that Sym004 potently increased cell kill by up to 10-fold following 9 Gy radiation exposure. Immunoblot analysis showed down-regulation of MAPK and AKT pathways, as well as changes in several key proteins involved in cell cycle progression, DNA damage repair and apoptosis. Flow cytometric analysis confirmed a significant increase of cells in S phase 24 hrs following 6 Gy radiation in control cells. However, treatment with Sym004 preceding radiation induced a significant G1 and G2 arrest accompanied by a reduction in S phase. Interestingly, we found a significant increase in apoptosis 48 hrs after radiation. These results suggest that Sym004 arguments radiation response via the induction of cell cycle arrest followed by the induction of apoptosis and cell death likely reflecting inhibitory effects on DNA damage repair. Finally, using single dose or fractionated radiation experiments in human tumor xenograft models, we found that the combination of Sym004 and radiation resulted in a significant delay in tumor regrowth and superior anti-tumor effects than treatment with drug or radiation alone. Taken together, these data reveal the strong capacity of Sym004 to augment radiation response in lung and H&N cancers. The unique action mechanism of Sym004 warrants further investigation as a promising EGFR targeting agent combined with radiotherapy in cancer therapy. (*Pedersen et al., Cancer Res 70:588∼597, 2010)

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 2720. doi:1538-7445.AM2012-2720
Abstract 2721: MEHD7945A, dual specific antibody against EGFR and HER3, augments radiation response in head and neck squamous cell carcinoma
Authors: Li Chunrong , Huang Shyhmin , Armstrong Eric A. , Sliwkowski Mark X. , Amler Lukas C. , Harari Paul M.
Published: August 2012

The HER receptor family members (EGFR, HER2, HER3 and HER4) play an important role in tumorigenesis. High EGFR expression levels correlate with poor prognosis and resistance to therapy for many epithelial tumors. Combining EGFR inhibition with radiation has been extensively studied in head and neck squamous cell carcinoma (HNSCC). Increasing evidence implicates HER3 as a key mediator of response and resistance to EGFR targeted therapies. We therefore examined the capacity of a dual specific antibody MEHD7945A, that can simultaneously target EGFR and HER3, to modulate radiation response in HNSCC. We characterized 10 HNSCC cell lines for their EGFR and HER3 expression. Immunoblot analysis confirmed that MEHD7945A significantly inhibited basal and radiation-induced EGFR and HER3 phosphorylation and downstream MAPK and AKT signaling. MEHD7945A consistently inhibited tumor cell growth in culture ranging from 30∼80%. The growth inhibitory effect of MEHD7945A was more potent than that observed with anti-EGFR or anti-HER3 antibody alone. Using clonogenic survival assay, we found that MEHD7945A significantly enhanced radiosensitivity in HNSCC cells. Once again, this effect of MEHD7945A was more potent than that observed with anti-EGFR or anti-HER3 antibodies. Treatment with MEHD7945A and radiation induced cell cycle arrest in G1 and G2 phases. Tumor cells eventually processed to apoptosis without successful DNA damage repair, as reflected by increased apoptotic populations detected by AnnexinV/PI staining. In addition, an increase of nuclear γ-H2AX foci was observed in cells receiving combination MEHD7945A and radiation. We administered MEHD7945A systemically to athymic mice bearing human tumor xenografts. Using single dose and fractionated radiation schedules, we observed that combined MEHD7945A and radiation was significantly more potent than single modality treatment to induce HNSCC tumor growth inhibition. These in vitro and in vivo results indicate that MEHD7945A can sensitize cells to radiation and inhibit HNSCC tumor growth, suggesting the potential of MEHD7945A as a radiation sensitizer for future clinical investigations.

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 2721. doi:1538-7445.AM2012-2721
Abstract 2722: Active recruitment of immune effector cells mediates in vivo tumor growth inhibition by enavatuzumab, an antibody to human TWEAK receptor
Authors: Ye Shiming , Fox Melvin , Belmar Nicole , Sho Mien , Chao Debra T. , Choi Donghee , Fang Yuni , Zhao Vivian , Keller Stephen , Starling Gary C. , Culp Patricia A.
Published: August 2012

Enavatuzumab (PDL192) is a humanized anti-TWEAK receptor antibody currently under clinical evaluation for the treatment of solid malignancies. Enavatuzumab is postulated to exert its potent anti-tumor activity in xenograft models through two distinct mechanisms of action: direct inhibition of tumor cell growth and Fc-mediated function. The goal of this study was to elucidate the role of immune effector cells in Fc-mediated function. The initial evidence for a role of effector cells was obtained in a subset of tumor xenograft mouse models which responded to enavatuzumab but did not respond to a version of enavatuzumab containing a mutation in the FcαRIII binding region. Subsequent analysis of circulating effector cells showed increased expression of activation markers DX5 and CD27 on monocyte-like cells (CD45+CD11bHigh) and DX5 on NK-like cells (CD45+CD11bLow) after enavatuzumab treatment in xenograft models dependent on Fc-FcR interactions for enavatuzumab efficacy. The involvement of effector cells was further confirmed by immunohistochemistry, which revealed strong infiltration of CD45+ effector cells into tumor xenografts in responding models, but minimal infiltration in non-responders. Consistent with the in vivo xenograft studies, human effector cells migrated towards enavatuzumab-treated tumor cells in vitro. Effector cells preferentially migrated toward in vivo responsive tumor cells, and the majority of migratory cells were monocytes and NK cells. Conditioned media from enavatuzumab-treated tumor cells also induced migration, and contained elevated levels of cytokines/chemokines, including IL8 and MCP-1. The presence of an anti-MCP-1 neutralizing antibody in enavatuzumab-treated tumor cell conditioned medium significantly blocked effector cell migration, suggesting that MCP-1 might be responsible for effector cell migration triggered by enavatuzumab. We also observed elevated levels of human MCP-1 in the serum of both enavatuzumab-treated xenograft mouse models and in a subset of patients from the enavatuzumab Phase I clinical study. In summary, in vivo and in vitro studies suggest that enavatuzumab exerts its potent anti-tumor activity, in part, by actively recruiting effector cells and activating effectors to kill tumor cells. In addition, enavatuzumab-induced chemokines may be potential pharmacodynamic biomarkers and warrant further evaluation in clinical studies.

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 2722. doi:1538-7445.AM2012-2722
Abstract 2725: Preclinical development of an Fc-enhanced anti-B7-H3 monoclonal antibody with potent anti-tumor activity
Authors: Loo Deryk T. , Alderson Ralph , Chen Francine , Huang Ling , Zhang Wenjun , Gorlatov Sergey , Burke Steve , Ciccarone Valentina , Li Hua , Yang Yinhua , Son Thomas , Chen Yan , Li Jonathan , Rillema Jill , Licea Monica , Liang Tony , Mather Jennie P. , Koenig Scott , Stewart Stanford J. , Johnson Syd , Bonvini Ezio , Moore Paul
Published: August 2012

Antigens that are tumor-specific or over-expressed on cancer cells represent opportunities for developing target-specific antibody-based therapeutics. Utilizing a non-target-biased intact cell-based immunization approach, we have generated greater than 1600 mAbs to cell-surface proteins that are expressed on cancer cells. A subset of the mAbs exhibit differential reactivity to tumor cells compared to normal cells. One of the differentially expressed proteins identified was B7-H3 (also referred to as CD276). B7-H3 is a member of the B7 family of immune regulatory proteins. Over-expression of B7-H3 has been correlated with disease severity and outcome in a growing number of cancer types, and several lines of evidence support a functional role for B7-H3 in cancer. In this report we describe the development of a humanized anti-B7-H3 mAb, designated MGA271, which bears an engineered Fc domain that imparts enhanced antibody-dependent cellular cytotoxicity (ADCC) through increased affinity for the human activating Fc-gamma receptor IIIA (CD16A) and decreased affinity for the human inhibitory Fc-gamma receptor IIB (CD32B). MGA271 displays strong reactivity to multiple tumors including kidney, prostate, pancreatic, breast, colon, gastric and ovarian cancer as well as melanoma, but limited reactivity toward normal human tissues. Independently of the donor's CD16A genotype, MGA271 mediates ADCC in vitro against human tumor cell lines representing these tumor types, as well as to human lung and gastrointestinal cell lines that exhibit properties of cancer stem cells. MGA271 exhibits potent anti-tumor activity toward B7-H3-expressing tumor xenografts in mice knocked-out for the murine CD16 gene and transgenic for the low affinity allele of human CD16A. Single- and repeat-dose toxicology studies were carried out in cynomolgus monkeys and no significant test article-related safety findings were observed. Taken together, these data support the clinical development of MGA271 for the treatment of patients who have B7-H3-expressing cancers.

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 2725. doi:1538-7445.AM2012-2725
Abstract 2731: Cetuximab resistance is associated with increased dependence on lipogenesis
Authors: Lu Yang , Lu Haiquan , Li Xinqun , Fan Zhen
Published: August 2012

Sterol regulatory element binding proteins (SREBPs) are key transcriptional regulators of cellular lipid homeostasis. By regulating the maturation of SREBPs through the PI3K/Akt and MEK/Erk signaling pathways, the epidermal growth factor receptor (EGFR) regulates de novo lipogenesis, which is essential for the structural needs of proliferation of cancer cells. The objective of current study is to determine the role of inhibition of lipogenesis by cetuximab, an FDA-approved EGFR-blocking antibody, in cetuximab-induced antiproliferative/antisurvival effects in cancer cells and to identify new combinations of cetuximab with approaches interfering with lipid metabolism for improved therapy. We found that addition of cetuximab into culture medium inhibited the activation of SREBP-1 (appearance of a nuclear form through cleavage of SREBP-1 precursor) in HN5 head and neck cancer cells but not in a cetuximab-resistant subline of HN5 cells (HN5R). Compared with parental HN5 cells, HN5R cells exhibit remarkably increased sensitivity to treatment with two pharmacological lipogenesis inhibitors, C75 (a fatty acid synthase inhibitor) and TOFA (an acetyl-CoA carboxylase inhibitor), suggesting that the cetuximab-resistant cells are more dependent on de novo fatty acid synthesis for survival, and combination of cetuximab with lipogenesis inhibitors may be a novel combination therapy. On the other hand, the increased dependence of cancer cells on lipogenesis suggests that cetuximab-resistant cells might also be sensitive to agents that promote fatty acid α-oxidation. We found treatment of HN5R cells with fenofibrate, an agonist of peroxisome proliferator-activated receptor alpha that transcriptionally activates the genes for inducing fatty acid α-oxidation, disrupted the redox balance in the cetuximab-resistant cells, leading to increased production of ROS and depolarization of the mitochondrial membrane potential that resulted in apoptosis. In summary, our data indicate that the antiproliferative/antisurvival effects of cetuximab in cancer cells depend on effective inhibition of lipogenesis. Pharmacological approaches that forcibly switch cancer cell metabolism from aerobic glycolysis to fatty acid α-oxidation may overcome cetuximab resistance.

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 2731. doi:1538-7445.AM2012-2731
Abstract 2734: c-Met antibody LY2875358 (LA480) shows differential antitumor effects in non-small cell lung cancer
Authors: Zeng Wei , Yan Lei , Peek Victoria , Wortinger Mark , Tetreault Jonathan , Xia Jinqi , Chow Chi-Kin , Manro Jason R. , Stephens Jennifer R. , Weir Spring N. , Tang Ying , Vaillancourt Peter , Lu Jirong , Yan Betty S. , Liu Ling
Published: August 2012

c-Met is a member of the receptor tyrosine kinase family and is the receptor for hepatocyte growth factor (HGF). c-Met is involved in many mechanisms of cancer proliferation and metastasis. Inappropriate activation of c-Met can be induced by ligand-independent mechanisms such as gene amplification, specific genetic mutations, and transcriptional up-regulation, or by ligand-dependent autocrine or paracrine mechanisms. Lung cancer is the leading cause of cancer death worldwide. Despite the successful development of EGFR- or EML4-ALK-targetd therapies, treatment options remain limited for patients with advanced lung cancer, making the identification of new therapeutic targets essential. c-Met expression was reported in 41-72% non-small cell lung cancer (NSCLC), amplification of c-Met occurs in 5-10 % of patients, and c-Met mutations have been detected in 8-13% of patients. We have developed a bi-valent c-Met antibody LY2875358 (LA480), which blocks ligand-dependent and ligand-independent c-Met activations. It is currently in clinical development. Here, we have demonstrated that LY2875358 alone or in combination with standard-of-care (SOC) affected cell proliferation, migration and signal transduction in NSCLC cells with c-Met gene amplification, mutations and overexpression. In vitro, LY2875358 induces wild type and mutant c-Met internalization and degradation. In vivo, LY2875358 alone shows a marked antitumor activity in Met amplification NSCLC xenograft models. The combination of LY2875358 with SOC chemotherapeutics treatments has better efficacy than either treatment alone, both in vitro and in vivo.

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 2734. doi:1538-7445.AM2012-2734
Abstract 2743: Triapine sensitizes ovarian cancer cells to platinum drugs and PARP inhibitors
Authors: Lin Z. Ping , Ratner Elena S. , Sartorelli Alan C.
Published: August 2012

Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone) is a ribonucleotide reductase (RNR) inhibitor that is 1000-times more potent than clinically-used hydroxyurea. Consisting primarily of R2 and R1 subunits during the S phase of the cell cycle, RNR catalyzes the rate-limiting step in the production of deoxyribonucleotides (dNTPs) required for DNA synthesis. Triapine chelates iron to form the triapine-Fe complex that quenches the tyrosyl radical at the R2 subunit and leads to enzymatic inactivation. In recent phase I and II trials, treatment of locally advanced cervical cancer with triapine in combination with cisplatin and radiation was well tolerated and produced high durable complete clinical responses in patients. This promising combination therapy may be attributable to the inhibitory effects of triapine on the repair of cisplatin- and radiation-induced DNA damage. However, the exact DNA repair mechanisms modulated by triapine remain poorly understood. In this study, we demonstrate that treatment of ovarian cancer cells with triapine prompts rapid and prolonged depletion of dATP/dNTP pools, which in turn leads to formation of DNA double strand breaks (DSBs) and inhibition of DNA synthesis in S and G2/M phases of the cell cycle. Furthermore, we show that treatment with triapine results in enhanced sensitization of BRCA-proficient (wild-type) ovarian cancer cells to platinum drugs (cisplatin and carboplatin) and the PARP inhibitor olaparib. Both platinum drugs and PARP inhibitors indirectly cause DSBs which require BRCA1- and BRCA2-dependent homologous recombination (HR) to repair. Collectively, these results suggest that triapine acts to abrogate replicative DNA synthesis and post-replication repair, thereby deterring HR repair of DSBs caused by platinum drugs and other DNA damaging modalities. While 70% of ovarian cancer patients initially respond to platinum-based chemotherapy, the majority of these patients will develop recurrent cancer resistant to the platinum drugs. Emergence of platinum-resistant cancer populations may be associated with increasing proficiency of cancer cells to employ HR to repair DNA damage. Given that, our findings provide the rationale for the use of triapine to enhance the efficacy of platinum-based chemotherapy and PARP inhibitors, and potentially eradicate platinum-resistant ovarian cancer.

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 2743. doi:1538-7445.AM2012-2743
Abstract 2747: Synergistic antileukemic activity of F14512 in combination with AraC
Authors: Vandenberghe-Huez Isabelle , Pillon Arnaud , Créancier Laurent , Gomes Bruno , Annereau Jean-Philippe , Fournier Emmanuel , Brel Viviane , Cartron Valérie , Chansard Nathalie , Pourtau Sandrine , Roy Sabine , Blanchet Jean-Christophe , Verdier Jérôme , Dejean Caroline , Ricome Christel , Offrete Vanessa , Gras Stéphane , André Karine , Guminski Yves , Bailly Christian , Guilbaud Nicolas , Kruczynski Anna
Published: August 2012

New antileukemic agents are urgently needed to achieve improvement of the survival of patients suffering from Acute Myelogenous Leukemia (AML). F14512 combines an epipodophyllotoxin core with a spermine moiety that targets cells with a high demand for polyamines such as cancer cells. F14512 exhibits a high level of in vivo anti-tumor activity in a series of experimental murine and human solid tumor models and has entered into clinical phase one. In this study, we investigated the in vivo antileukemic activity of F14512 against cell line or primary human AML models and evaluated its potential in combination with the reference antileukemic agent, AraC. HL60 cells or AML cells collected from different patients were engrafted onto NSG mice. Using flow cytometry and q-PCR analysis, we demonstrated that multiple administrations of F14512 for 3 weeks resulted in an extensive reduction of AML cell number in the bone marrow and blood of treated mice. We also showed in vitro and in vivo synergistic activity of F14512 in combination with AraC in HL-60 and primary AML models when both compounds were used at suboptimal doses. The mechanisms triggering primary leukemic cell death were investigated and our results indicated that senescence could be involved. Collectively, these results demonstrate that F14512 exhibits a marked in vivo antileukemic activity, supporting the Phase I clinical trials of this novel promising drug candidate.

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 2747. doi:1538-7445.AM2012-2747
Abstract 275: Enhancing the anticancer activity of pegylated interferon by dual specificity protein phsphatase 1 (DUSP1) silencing in hepatocellular carcinoma based replicon
Authors: Choi Jung Eun , Hur Wonhee , Lyoo KawngSoo , Hong Sung Woo , Kim Sung Woo , Lee Yong Ki , Yoon Seung Kew
Published: August 2012

Chronic hepatitis C infection is one of the important causes of hepatocellular carcinoma (HCC), or primary liver cancer, throughout the world. Worldwide, HCC causes over a million deaths per year (about 10% of all deaths in the adult age range), making it one of the most common malignancies in adults. Although pegylated interferon (PEG-IFN) is a treatment for HCC among patients with HCV, non-responders remains a challenging issue. In this study, we investigated whether anticancer activity of IFN was enhanced after dual specificity protein phosphatase 1 (DUSP1) silencing by regulation of HCV titer. To investigate anticancer activity of IFN by DUSP1, we silenced DUSP1 expression into HCC based replicon. The DUSP1 expression was determined using RT-PCR and western blot analysis. Next, the quantification of viral RNA was measured by real-time PCR. The activity of the proteins belonged to IFN-mediated signaling pathway was detected by Western blot analysis. The number of copies of viral RNA was more decreased in DUSP1 than negative control. Furthermore, the activity of ERK was enhanced through DUSP1 silencing under treatment of IFN. Taken together, these results showed that modulation of DUSP1 activity enhanced the anticancer activity of IFN. Our study suggested that DUSP1 may play an important role in resistance of IFN non-responder patients.This work was supported by Basic Science Research Program through the National Research Foundation of Korea (2011-0026332).

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 275. doi:1538-7445.AM2012-275
Abstract 2750: Short-chain lipids catalyse intracellular drug accumulation by a transient molecular gateway that allows plasma membrane traversal
Authors: van Hell Albert J. , Gueth Dayana Martins , Melo Manuel Nuno , Marrink Siewert Jan , Verheij Marcel
Published: August 2012

BACKGROUND: The lipid composition of the plasma membrane provides an effective barrier towards exogenous, potentially cytotoxic molecules. As a consequence, membrane traversal of most therapeutic drugs is sub-optimal and remains a major limitation for clinical efficacy. We previously identified a class of short-chain sphingolipids that facilitate the accumulation of amphiphilic compounds, including the cytostatic drug doxorubicin, within tumor cells, leading to improved therapy response. AIM: In order to elucidate the mechanism of action of short-chain lipids, both in vitro and model membrane studies and in silico molecular dynamics simulation experiments were designed. RESULTS: We demonstrate that short-chain sphingolipids act at the level of the plasma membrane, however, independently of lipid microdomain (raft) formation or membrane proteins. In artificial lipid membranes of well-defined compositions short-chain sphingolipids enhanced doxorubicin-membrane traversal similar to cell membranes; N-octanoyl-glucosylceramide decreased the translocation half-time of doxorubicin over liquid ordered lipid membranes by a factor 1.93 (p < 0.05). In case of liquid disordered membranes, a comparable effect was observed (factor 1.91; p < 0.05); lipid phase separation (raft formation) did not affect enhanced doxorubicin translocation. Molecular dynamics simulations revealed that the short-chain lipids act by assembling a transient molecular gateway for doxorubicin. Accordingly, the free energy barrier for the hydrophilic head group of the drug to dehydrate and translocate to the opposite side of the membrane is reduced by two-fold (p < 0.05). CONCLUSION: Short-chain lipids catalyse the transbilayer movement of amphiphilic cytostatic drugs to achieve higher intratumoral drug accumulation, and their action is explained by the formation of a transient lipid gateway in the plasma membrane of the tumor cell, thus facilitating drug translocation and subsequent intracellular accumulation.

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 2750. doi:1538-7445.AM2012-2750