bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3878: Newly identified p53-pathway restoring small molecule, CB002 analog #4 induces apoptosis and appears non-toxic in vivo
Authors: Borrero Liz J. Hernandez , Lev Avital , Zhou Lanlan , Dicker David T. , El-Deiry Wafik S.
Published: August 2019

The transcription factor encoding TP53 tumor suppressor gene is mutated in more than half of human cancers. TP53 accounts for therapy resistance and poor patient survival in colorectal and other cancers. Upon cellular stress, p53 protein determines cell fate through the regulation of cell senescence, cell cycle arrest, and apoptosis pathways. Distinct from other tumor-suppressors, mutated p53 can acquire a gain-of-function activity, leading to chemotherapy resistance and a more aggressive tumor phenotype. Direct therapeutic targeting of transcription factors is challenging especially when reactivation is needed; thus, to date, there are no FDA approved drugs for p53 functional restoration in tumors harboring p53 mutations. To overcome this, we have screened for small molecules capable of restoring wild-type p53 pathway signaling rather than direct physical restoration of its function. We identified a small molecule, CB002 analog #4 capable of restoring the p53 pathway in HCT116, SW480 and DLD-1 colorectal cancer cell lines as indicated by the increased expression of p53-target genes NOXA, p21 and DR5, and apoptotic markers upon treatment. We found that analog #4 enhances ethidium homodimer staining of dead cells and decreases the number of positive Ki67 staining cells in colorectal cancer patient organoids. Sub-G1 analysis demonstrated that analog #4 does not induce apoptosis in normal human fibroblasts and preliminary in vivo studies indicate that it can be safely administered to mice. We are investigating the in vivo efficacy of analog #4 in addition to its mechanism of action through micro-array experiments. Our data supports the concept that small molecules can restore the p53-pathway as a therapeutic strategy that can be translated into a clinical setting.

Citation Format: Liz J. Hernandez Borrero, Avital Lev, Lanlan Zhou, David T. Dicker, Wafik S. El-Deiry. Newly identified p53-pathway restoring small molecule, CB002 analog #4 induces apoptosis and appears non-toxic in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3878.
Abstract 3886: Impact of nanosuspension of CZ48, a lactone stabilized camptothecin, on the biliary excretion and enterohepatic recycling of its active moiety, camptothecin
Authors: Chow Diana S-L , Kim Yu Jin , Dong Dong , Li Xiaohui
Published: August 2019

The biliary excretions of CZ48, a lactone-stabilized camptothecin (CPT), and CPT were evaluated in bile duct-cannulated SD rats after a single oral administration of CZ48 in two different types of formulations, co-solvent solution (CoS, control, in the mixture of DMSO, PEG 400, and EtOH (2:2:1, v/v/v) at 10 mg/ml) and nanosuspension (NS with stabilizers of TW 80 and F-108, sustained release of CZ48). Enterohepatic recycling was further characterized by collecting bile intermittently or continuously to modulate the recycling system in the rats. The results demonstrated that CZ48 and CPT were secreted into the bile as their parent forms with the dominant secretion of CPT as compared to CZ48. The AUCs0-12h of CPT in bile were 213.45 ± 232.09 and 250.40 ± 134.83 ng/ml*h/[mg/kg] in CoS and NS groups, respectively, which were 18.39 and 34.16 times higher than those of CZ48 (11.61 ± 7.99 ng/ml*h/[mg/kg] in the CoS group and 7.33 ± 2.22 ng/ml*h/[mg/kg] in the NS group). On the contrary, the AUCs0-12h of CZ48 in plasma were 6.10 and 6.80 times higher than those of CPT in CoS and NS groups, respectively. There was no significant impact of NS on the plasma AUCs0-12h and biliary excretions of CZ48 and CPT. Their concentrations in plasma and biliary excretions were sustained for 8 or 12 h post oral dose. Moreover, a pharmacokinetic co-model for CZ48 and CPT in plasma and bile was developed to characterize the biliary secretion and saturable process of enterohepatic recycling of CZ48 and CPT in rats.

Citation Format: Diana S-L Chow, Yu Jin Kim, Dong Dong, Xiaohui Li. Impact of nanosuspension of CZ48, a lactone stabilized camptothecin, on the biliary excretion and enterohepatic recycling of its active moiety, camptothecin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3886.
Abstract 3892: Population pharmacokinetics of siltuximab: An analysis across tumor types
Authors: Nikanjam Mina , Yang Jin , Capparelli Edmund V.
Published: August 2019

Introduction: Siltuximab is an IL-6 inhibiting monoclonal antibody which has been studied in solid tumors and hematologic malignancies, but no comprehensive pharmacokinetic (PK) analysis has been conducted to determine the impact of disease on siltuximab disposition.

Methods: Siltuximab pharmacokinetic data from 7 Phase I and II clinical trials included healthy subjects, Castleman’s disease, ovarian cancer, non-Hodgkin’s lymphoma, multiple myeloma, smoldering multiple myeloma, chronic lymphocytic leukemia, renal cell carcinoma, and solid tumors with KRAS mutations. Siltuximab was most commonly dosed at 11 or 15 mg/kg (range 1 - 20 mg/kg) with 70% of patients receiving multiple doses. Plasma samples were obtained 0.33 h - 27 weeks after dosing with siltuximab concentrations determined using a validated ELISA assay. The PK analysis was performed using nonlinear mixed effects modeling (NONMEM 7.3) and included data from 465 subjects (7,761 samples).

Results: Siltuximab concentration data was best fit with a two-compartment model. Healthy volunteer status (HV), Castleman’s disease (CD), albumin (ALB), and ALT were independent predictors of clearance (CL), while ALB, HV, serum creatinine (SCR), weight (WT), and smoldering multiple myeloma predicted volume of distribution (Vdss). There was no impact of dose level on CL or Vdss. In the final PK model CL was described as:

CL (mL/hr) = 8.93 x (ALB/4.1)-0.843 x (ALT/17)-0.0964 x 1.24 (if HV) x 0.765 (if CV);

between subject variability was 41.0%. The final model was used to simulate a dose of 11 mg/kg for 1000 subjects with the median (IQR) exposure (AUC) and CL as follows:

CL (mL/hr)AUC (mcg*day/mL)Half-lifeβ (days)Healthy volunteers6.61 (4.99 – 8.63)4,855.8 (3,717.4 - 6,426.3)24.5 (19.2 – 33. 6)Castleman’s Disease11.11 (8.48 - 14.36)2,884.3 (2,233.7 - 3,782.5)19.1 (14.6 - 25.0)Other tumor types9.13 (6.93 - 11.52)3,514.5 (2,786.2 - 4,627.0)22.2 (17.5 - 30.5)

Conclusions: This combined population PK analysis demonstrates that clearance can differ with disease type consistent with previously published variations in IL-6 activity. These population differences along with significant between subject variability suggest that clinical and disease factors influence siltuximab disposition and may need to be considered in dosing requirements.

Citation Format: Mina Nikanjam, Jin Yang, Edmund V. Capparelli. Population pharmacokinetics of siltuximab: An analysis across tumor types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3892.
Abstract 3894: Determination of the efficacious Entrectinib exposures required for pathway inhibition and anti-tumor activity in a subcutaneous and intracranialTPM3-NTRK1mutant tumor model
Authors: Cruz Cecile C. de la , Hunsaker Thomas , Vazvaei Faye , Draganov Dragomir , Yu Li , Merchant Mark
Published: August 2019

Entrectinib is a selective and brain penetrant inhibitor with potency against TRKA, TRKB, TRKC, ROS1 and ALK currently in clinical development for the treatment of tumors harboring NTRK or ROS1 gene fusions. In multiple non-clinical models harboring NTRK or ROS1 gene fusions, entrectinib demonstrates potent tumor growth inhibition leading to tumor regressions. Entrectinib achieves exposure in the brain across multiple species with brain-to-plasma concentration ratios of 0.4 in mice, 0.6-1.5 in rats, and 1.4-2.2 in dogs after multiple oral administration. Previously Cook, et al. demonstrated that entrectinib demonstrates anti-tumor efficacy in a BCAN-NTRK1 glioma model, however only testing higher doses. Here we sought to better understand the effective exposures of entrectinib required for pathway inhibition and anti-tumor efficacy through dose-ranging efficacy, pharmacokinetics (PK) and pharmacodynamics (PD) studies using the TPM3-NTRK1 KM12-Luciferase (KM12-Luc) tumor model inoculated subcutaneously or intracranially. In the subcutaneous setting, entrectinib treatment results in significant dose-dependent inhibition of TRKA pathway signaling for up to 12 hours and anti-tumor activity with doses of 5 mg/kg (dosed orally (PO), every day (QD)) and above resulting in strong pathway suppression and tumor regressions. PK analysis demonstrated that an exposure of AUC24h of ≥20 µM.hr was associated with potent TRKA pathway inhibition and tumor growth inhibition. In the intracranial setting, entrectinib similarly demonstrated a dose-dependent effect on inhibition of tumor bioluminescence and enhanced animal survival. Pathway inhibition was observed at all doses of entrectinib with significant activity observed at doses of 5 mg/kg, PO, QD and above. In contrast to tumors inoculated subcutaneously, entrectinib doses of 15 mg/kg, PO, twice daily (BID) or 30 mg/kg, PO, QD were required to strongly inhibit anti-tumor efficacy with the highest dose of 60 mg/kg, PO, BID achieving full suppression of intracranial tumor growth. These data help to establish a model connecting entrectinib drug exposure in circulation and in the brain to pathway suppression and anti-tumor efficacy in an NTRK gene fusion tumor model, which support clinical use of entrectinib in patients with brain NTRK or ROS1 gene fusion tumors.

Citation Format: Cecile C. de la Cruz, Thomas Hunsaker, Faye Vazvaei, Dragomir Draganov, Li Yu, Mark Merchant. Determination of the efficacious Entrectinib exposures required for pathway inhibition and anti-tumor activity in a subcutaneous and intracranialTPM3-NTRK1mutant tumor model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3894.
Abstract 3897: Stability and safety evaluation of STRO-002, a site-specific anti-folate receptor alpha antibody-drug conjugate for the potential treatment of ovarian and endometrial cancers
Authors: Solis Willy , Almeida Venita De , Abrahams Cristina , Li Xiaofan , Heibeck Tyler , Bruhns Maureen , Galan Adam , Hoffman Heidi , Kiss Robert , Hallam Trevor , Lupher Mark
Published: August 2019

Antibody-drug conjugates (ADCs) constitute an expanding class of therapeutic molecules in preclinical and clinical development for multiple oncology indications. Folate receptor alpha (FolRα) is a glycosylphosphatidylinositol-linked cell-surface glycoprotein that is overexpressed in ovarian, endometrial, lung, and triple negative breast cancers. In contrast, FolRα is minimally expressed on normal tissues, thus, making it an amenable ADC target. STRO-002, a site-specific ADC, is comprised of 3-aminophenyl hemiasterlin cytotoxic drug (SC209) conjugated to an aglycosylated anti-FolRα IgG1 antibody through a protease-cleavable linker at two engineered non-natural amino acids in each heavy chain (DAR ~4).

In vitro and in vivo stability studies, showed that STRO-002 is highly stable in circulation, with the warhead SC209 predominantly accumulating in tumor tissue. Toxicology and toxicokinetic studies were conducted to determine the safety profiles for STRO-002 and its metabolite SC209 in cynomolgous monkeys and rats, respectively. In single-dose toxicology studies in rats, SC209 was tolerated up to 0.6 mg/kg with the main toxicity findings predominantly found in hematopoietic/lymphoid tissue, consistent with tubulin targeting chemotherapeutic drugs. In a tissue cross-reactivity study with normal human tissues, STRO-002-specific membranous staining was detected in Fallopian tubes, kidney (tubules), and placenta (trophoblasts). In a definitive safety study in cynomolgus monkeys, pharmacologically relevant model for toxicity testing, STRO-002 was tolerated at up to 9 mg/kg when intravenously administered on days 1 and 22 followed by a 4-week observation period. The most prominent STRO-002-related antigen-independent toxicity finding was dose-related, minimal to marked, and cyclical neutropenia. There were no antigen-dependent toxicity findings and no evidence of ocular toxicity. Toxicokinetic analysis confirmed dose proportional STRO-002 exposures (total antibody, ADC, and SC209 catabolite) at all doses tested. In summary, STRO-002 ADC has a favorable nonclinical safety and pharmacokinetic profiles and a Phase I study of STRO-002 in patients with ovarian and endometrial cancer has been initiated.

Citation Format: Willy Solis, Venita De Almeida, Cristina Abrahams, Xiaofan Li, Tyler Heibeck, Maureen Bruhns, Adam Galan, Heidi Hoffman, Robert Kiss, Trevor Hallam, Mark Lupher. Stability and safety evaluation of STRO-002, a site-specific anti-folate receptor alpha antibody-drug conjugate for the potential treatment of ovarian and endometrial cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3897.
Abstract 39: Microvessel-on-a-chip for investigating glioma-vascular interactions
Authors: Gerigk Magda , Bulstrode Harry J. , Huang Yan Yan Shery
Published: August 2019

Introduction: Gliomas, which are heterogeneous tumors made up of malignant glial and stromal cells, can often grow and progress without angiogenesis and thus escape anti-angiogenic therapies. One of the alternative mechanisms of tumor blood supply is vessel co-option, where cancer cells migrate along the pre-existing vessel of the host organ, preserving the blood-brain barrier (BBB). However, studying this phenomenon is currently limited mainly to animal models. With the push to reduce in vivo approaches, developing an experimental, organ-on-a-chip model to encompass one or more tractable microenvironmental factors, will enable us to better understand their mechanistic roles in brain tumor progression.

Methods and Results: An extracellular matrix-integrated PDMS-based microfluidic chip with a rounded microvessel, mimicking the BBB, was generated using a human microvascular cell line (hCMEC/D3), in the presence of flow. In the chip, a vessel of ~100µm diameter was interfaced with a 3D brain cancer cell culture (either U87, glioma neural stem or normal neural stem cell, embedded in a collagen-based ECM). The system was coupled with live-cell imaging and image analysis, which enabled tracking of cell-cell and cell-microenvironment interactions. Changes in gene expression and protein distribution in endothelial cells were successfully quantified, thus enabling the characterization of the influence of cancer cells population on the microvessel.

Conclusions: Development and optimization of the novel device has given us the opportunity to study the influence of glioma cells on normal brain endothelium, when agiogenesis does not occur. Crucially, this can be done in controlled, user-defined environment (i.e. choice of ECM components and stiffness, microvessel size and flow rate) unlike in animal models.

Note: This abstract was not presented at the meeting.

Citation Format: Magda Gerigk, Harry J. Bulstrode, Yan Yan Shery Huang. Microvessel-on-a-chip for investigating glioma-vascular interactions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 39.
Abstract 3903: Acute toxicity studies of ethanolic fruit-skin extract of Annona muricata
Authors: Iyanda-Joel Wisdom O. , Israel-Ovirih Sandra O. , Chinedu Shalom N. , Iweala Emeka EJ
Published: August 2019

Recent reports have shown that the currently high demand for Annona muricata fruits and plant products is most likely due to their selective cytotoxic activity, where extracts and subsequent pure compounds exhibited more toxicity to cancer cell lines than standard drugs and even increased the viability of normal cells at certain concentrations. The current study explored the phytochemical screening and acute toxicity profile of ethanolic fruit-skin extract of Annona muricata (ESA) in female Wistar rats. Phytochemical screening were carried out following stipulated protocols while twenty-five female Wistar albino rats were treated with 2000 mg kgbwt-1and 5000 mg kgbwt-1 ESA for 24 - 72 hours and after 14 days to evaluate their toxicity against biochemical (ALT, AST, ALP, urea, creatinine, triglycerides, cholesterol, albumin and total protein), hematological (RBC, WBC, PCV, platelet count, MCV, MCH and MCHC, neutrophil, lymphocyte and monocyte) and histopathological parameters. The phytochemical screening of extract collectively revealed the presence of alkaloids, flavonoids, phenols, quinones, saponins, steroids, tannins and terpenoids. No sign of toxicity was observed in animals treated with ESA in the first critical four hours of dosage neither any mortality recorded. Toxicological assessment of ESA showed significant difference in values of extract-treated animals mostly at 5000 mg kgbwt-1 compared to normal control on ALT, ALP, WBC, M, N, PCV, MCH, MCV and platelet count within 72 hours of treatment compared to normal control but mostly later reversed after 14 days. Histopathology results also showed significant differences in morphology of certain organs compared to control with reversal of some lesions after 14 days. Ultimately, ethanolic fruit-skin extract of Annona muricata is non-toxic at moderate concentrations and may serve as a huge potential for nature-friendly antiproliferative and antitumour agents.

Note: This abstract was not presented at the meeting.

Citation Format: Wisdom O. Iyanda-Joel, Sandra O. Israel-Ovirih, Shalom N. Chinedu, Emeka EJ Iweala. Acute toxicity studies of ethanolic fruit-skin extract of Annona muricata [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3903.
Abstract 3935: PLK4 inhibition as a strategy for non-small cell lung cancer radiosensitization
Authors: Hayman Thomas J. , Bray Mark R. , Mason Jacqueline M. , Mak Tak W. , Contessa Joseph N.
Published: August 2019

Background/Purpose: Lung cancer remains the leading cause of cancer-related death. Concurrent chemoradiation is the standard of care for locally advanced non-small cell lung cancer (NSCLC). Despite advancements in treatment, local control remains an issue and survival is suboptimal, highlighting the need for novel therapeutic approaches. Polo-like kinase 4 (PLK4) is a serine/threonine kinase that controls centriole duplication. PLK4 is highly expressed in multiple malignancies including lung cancer. CFI-400945 is a specific PLK4 inhibitor currently undergoing clinical trial evaluation. As radiation causes cell death primarily via a mitotic death, we hypothesized that disruption of the mitotic machinery by inhibition of PLK4 would enhance the effects of radiation.

Methods: The effects of CFI-400945 on cell survival and radiation sensitivity were examined using the clonogenic survival assay in two KRAS-mutant lung cancer cell lines (H460 and A549). Confocal microscopy was utilized to determine the effects of PLK4 inhibition on radiation-induced mitotic catastrophe (defined as the presence of 2 or more distinct nuclear lobes within a single cell). Cell cycle distribution by flow cytometry was determined after treatment with CFI-400945 and radiation.

Results: Exposure of H460 and A549 lung cancer cell lines to 10nM CFI-400945 for 48h reduced clonogenic survival to 63.9% and 83.1% respectively. CFI-400945 treatment of H460 and A549 cells resulted in radiosensitization of both cell lines with dose enhancement factors (DEF) of 1.60 and 1.31. To understand the mechanism of enhanced radiosensitivity with CFI-400945 treatment the effects on radiation-induced mitotic catastrophe were determined. In both H460 and A549 cells the combination of radiation and PLK4 inhibition enhanced the proportion of cells undergoing mitotic catastrophe. The combination of CFI-400945 and radiation resulted in increased G2/M arrest and appearance of >4N populations by flow cytometric analysis when compared to drug or radiation treatment alone.

Conclusion: PLK4 inhibition with CFI-400945 enhances the radiosensitivity of lung cancer cell lines via mitotic catastrophe and G2/M arrest and these data support additional pre-clinical testing.

Citation Format: Thomas J. Hayman, Mark R. Bray, Jacqueline M. Mason, Tak W. Mak, Joseph N. Contessa. PLK4 inhibition as a strategy for non-small cell lung cancer radiosensitization [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3935.
Abstract 3942: Animal studies evaluating the safety of Tumor Treating Fields (TTFields) in the torso
Authors: Davidi Shiri , Munster Mijal , Cahal Shay , Giladi Moshe , Kirson Eilon D. , Weinberg Uri , Palti Yoram
Published: August 2019

TTFields therapy is an anti-neoplastic treatment modality targeting dividing cells by disrupting microtubules and septin filaments localization. TTFields therapy received FDA approval for the treatment of glioblastoma based on phase 3 studies demonstrating efficacy and high safety profile. TTFields are currently being tested as a treatment option for solid tumors in the torso. The aim of this work is to study whether TTFields’ safety profile is maintained in the torso, and specifically in tissues with high cellular proliferation rates. TTFields (2-3 V/cm) were applied for 2 weeks using the Novo-TTF 100 system to the rat torso at 150 and 200 kHz, intensities and frequencies known to be effective for the treatment of NSCLC, mesothelioma, pancreatic cancer, ovarian cancer and hepatocellular carcinoma. Throughout the treatment course, all animals underwent daily clinical examination by a certified experienced veterinarian. At the end of treatment, animal were euthanized and an experienced independent pathologist performed histological comparative evaluation of all major internal organs. No changes in the following parameters were observed: activity level, food intake, drinking, stools, motor neurological status and respiration. Further, no changes in weight were observed between the treated and control groups. No significant changes were observed in complete blood count and differential between the different groups. Histological analysis did not reveal any increase in pathological findings in the TTFields treated animals group. Taken together, these results demonstrate that safety of TTFields application at frequencies of 150-200 kHz to the rat torso and specifically to tissues with high cellular proliferation rates. Additional work is now underway to better understand the specificity of TTFields’ effects on rapidly dividing tumor cells.

Citation Format: Shiri Davidi, Mijal Munster, Shay Cahal, Moshe Giladi, Eilon D. Kirson, Uri Weinberg, Yoram Palti. Animal studies evaluating the safety of Tumor Treating Fields (TTFields) in the torso [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3942.
Abstract 3956: A novel compound screen for enhancing T-cell based immunotherapy identifies aurora kinases as a targetable mechanism for tumor immune escape in pancreatic ductal adenocarcinoma preclinical models
Authors: Ashkin Emily L. , Silverman Deborah , Punt Simone , Manrique Soraya Zorro , Williams Leila , Wang Yunfei , Hwu Patrick
Published: August 2019

Harnessing a patient’s immune system by attenuating endogenous immune checkpoints on T-cells has led to dramatic, durable tumor rejection for multiple tumor types. Nonetheless, many cancers, including pancreatic ductal adenocarcinoma (PDAC), still do not respond to immunotherapy. PDAC remains largely resistant to all therapies, leading to its notoriety as one of the most lethal malignancies, with a 6% 5-year survival rate. We aimed to find novel, targetable mechanisms by which tumors escape the adaptive immune system and resist immunotherapy. We conducted a high throughput screen of 1280 compounds producing a synergistic effect with T-cell killing to assess differences and similarities among distinct pathways inclusive between PDAC and melanoma. These screens identified several aurora kinase inhibitors as synergistic with autologous T-cell killing of tumor target. Here we present results underlying the mechanism by which aurora kinase inhibition enhances autologous T-cell mediated killing and may improve T-cell-mediated cancer immunotherapy. These findings may contribute to the design of new therapeutic combination strategies for enhancing immunotherapy treatment of melanoma, PDAC, and other “immunologically cold” tumors.

Note: This abstract was not presented at the meeting.

Citation Format: Emily L. Ashkin, Deborah Silverman, Simone Punt, Soraya Zorro Manrique, Leila Williams, Yunfei Wang, Patrick Hwu. A novel compound screen for enhancing T-cell based immunotherapy identifies aurora kinases as a targetable mechanism for tumor immune escape in pancreatic ductal adenocarcinoma preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3956.
Abstract 3965: Circulating levels of IFN gammaand neutrophil counts in breast cancer patients who received balixafortide and eribulin combination therapy
Authors: Zimmermann Johann , Douglas Garry , Romagnoli Barbara , Barker Debra , Obrecht Daniel
Published: August 2019

Background: Balixafortide (B) is a highly selective antagonist of the chemokine receptor CXCR4. Clinical proof-of-concept in combination with eribulin (E) was achieved in a recent Phase 1 single arm dose-escalation trial in patients with metastatic HER2-negative breast cancer (NCT01837095). Safety and tolerability of B in combination with E was similar to that of B or E monotherapy.

Anti-cancer effects of CXCR4 antagonists include sensitization of tumor cells to chemotherapy, suppression of metastatic spread, inhibition of angiogenesis, and activation of immune cells.

Methods: Plasma samples from patients who received initial E monotherapy (1.4 mg/m2, run-in cycle) or combination of B and E (escalating doses of B intravenous up to 5.5 mg/kg plus E 1.4 mg/m2 in 21 days cycles) were immediately processed and stored at -80°C. Circulating levels of IFN-γ, an important marker of anti-tumor immune response, were determined by a high-sensitive S-Plex assay (Meso Scale Diagnostics). Absolute neutrophil counts (ANC) were measured by automated hematology instruments.

Results: E monotherapy did not increase IFN-γ levels in the first 8 hours post dosing, but led to an increase after 24 hours. Combination with B modulated IFN-γ levels and led to a sustained ANC increase 5 days post dosing. The increase pre vs post treatment can be up to 100-fold and receded prior to the next treatment cycle. Conclusions: E treatment led to a strong, transient increase of plasma IFN-γ levels in breast cancer patients modulated by B. The ANC increase by B may balance possible neutropenic actions of E.

Citation Format: Johann Zimmermann, Garry Douglas, Barbara Romagnoli, Debra Barker, Daniel Obrecht. Circulating levels of IFN gammaand neutrophil counts in breast cancer patients who received balixafortide and eribulin combination therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3965.
Abstract 3970: PARP inhibitors increase expression of Type I interferon regulated genes mainly through trapping
Authors: Wielgos Monica E. , Jelinic Petar , Levine Douglas A.
Published: August 2019

Background: Currently, there are multiple ongoing clinical trials testing the efficacy of various poly (ADP-ribose) polymerase (PARP) inhibitors in combination with immune checkpoint blockade across many cancer types. However, there is no rationale as to which PARP inhibitor is best to use in these studies. Two PARPis (rucaparib and talazoparib) have been reported to activate IFN signaling genes through the stimulator of interferon genes (STING) pathway. The objective of this study is to characterize the effect of all clinically active PARPis on Type I interferon (IFN) regulated genes. We also aim to identify whether this effect is dependent on CHK1, which we have previously reported to be activated by PARP trappers (rucaparib, olaparib, niraparib, and talazoparib) and not by the mainly catalytic inhibitor (veliparib).

Methods: CCL5 and CXCL10 gene expression levels were measured using qRT-PCR in 293T after two days of treatment with the PARP inhibitors (velipairb, rucaparib, olaparib, niraparib, and talazoparib). CXCL10 mRNA levels were also measured in HGSOC BRCA wild-type cell lines (OVCAR3 and CAOV3) after two days of treatment with veliparib and talazoparib. We also measured CCL5 and CXCL10 expression after veliparib and niraparib treatment in 293T cells with stable CHK1 overexpression.

Results: The four PARP trappers consistently increased CCL5 and CXCL10 expression in 293T cells. Although, veliparib had little to no effect on the expression of these two genes as compared to the other four PARPis. CXCL10 mRNA levels were significantly upregulated after talazoparib treatment (p<0.01) but not affected after veliparib treatment in CAOV3 cells. Similarly, an increase in CXCL10 gene expression was observed in OVCAR3 cells (p<0.05). Although, veliparib also had a modest but not significant effect on CXCL10 levels. CCL5 and CXCL10 gene expression consistently increased when treated with niraparib in 293T cells with stable CHK1 overexpression. This same effect was not observed after veliparib treatment in 293T cells that stably overexpressed CHK1.

Conclusions: Our results suggest that all PARP trappers promote expression of IFN Type I regulated genes which may be dependent on CHK1 expression. These findings may better define the most ideal PARP and immune checkpoint inhibitor combination.

Citation Format: Monica E. Wielgos, Petar Jelinic, Douglas A. Levine. PARP inhibitors increase expression of Type I interferon regulated genes mainly through trapping [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3970.
Abstract 3972: Investigation of tumor intrinsic PD1/PD-L1 in canine urothelial carcinomas as a spontaneous translational model for human invasive bladder cancer
Authors: Wang Yu Jia , Pietrzak Katarzyna , Kocikowski Mikolaj , Argyle David , Hupp Ted , Parys Maciej
Published: August 2019

Urothelial carcinoma (UC) is the fourth most common malignancy in human and the most common form of urinary bladder cancer in dogs. This neoplasia tends to be invasive at advanced stages hence novel therapeutic approaches are urgently needed. As urothelial carcinomas share many similarities between the dog and human in the immunological responses, dogs are a perfect model for studying immunotherapeutic approaches. Recently immuno-checkpoint blockade using anti-PD1/PD-L1 antibodies have shown a promising effect and durable responses in the treatment of UC. Although until recently the PD1/PD-L1 axis was considered to be mostly affecting immune cells, recent reports identified, that PD-1/PD-L1 interaction is also capable of pro-tumorigenic signaling in melanoma and other cancers. Yet, little is known regarding this phenomenon in UC. In our study, we aim at identification of the expression level of PD-1 in canine UC and subsequently characterize the effect of overexpression and CRISPR-based knock-out of PD-1 and PD-L1. Using flow cytometry and immunocytochemistry, we identified that PD-1 is expressed on the surface of canine UC cell line. Interestingly, incubation with high concentration of PD-1 antibody decreased the proliferation rate of the tumor. After transfection with a PD-1 overexpression vector, we notice a significant morphological change and decrease in proliferation and colony formation. Our result provides the first report on PD-1 intrinsic signaling play as an important role in tumor growth of canine UC and thus may also be responsive to immune checkpoint blockade. The effect identified further strengthens the dog as a potential translational model for UC immunotherapy.

Citation Format: Yu Jia Wang, Katarzyna Pietrzak, Mikolaj Kocikowski, David Argyle, Ted Hupp, Maciej Parys. Investigation of tumor intrinsic PD1/PD-L1 in canine urothelial carcinomas as a spontaneous translational model for human invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3972.
Abstract 398: Overriding drug resistance in Philadelphia chromosome-positive acute B lymphoblastic leukemia by targeting both BCR-ABL and MAP4K signaling pathways
Authors: Ren Ruibao , Xiao Xinhua , Zhang Jianming , Jiao Bo
Published: August 2019

The Philadelphia chromosome (Ph) translocation, which leads to creation of a fusion gene product BCR-ABL, is found in chronic myelogenous leukemia (CML) and 20% of adult and 2-5% pediatric acute B-lymphoblastic leukemia (B-ALL). The selective ABL tyrosine kinase inhibitor (TKI) has been shown a remarkable clinical activity in patients with CML. The ABL TKI has also improved the clinical outcome of Ph+ B-ALL dramatically in combination with standard chemotherapy, but the morbidity and mortality of this disease remain high. The existence of ABL inhibitor-resistant leukemia cells in these patients indicates the presence of additional oncogenic pathways in Ph+ B-ALL. Discovery of a new therapeutic strategy to eradicate Ph+ B-ALL cells is, therefore, urgently needed. By using a chemical genetics approach, we identified a novel small molecule, AR4-13, which shows robust ABL kinase inhibition and potent pharmaceutical efficacy in Ph+ leukemias among 1094 cell lines from the Cancer Cell Line Encyclopedia (CCLE) project. Interestingly, AR4-13 possesses preferable potency than Dasatinib, a potent dual SRC/ABL TKI approved to treat CML and Ph+ B-ALL, to kill Ph+ B-ALL cells, but not do so in CML cells, both in vitro and in vivo. In particular, AR4-13 inhibits S6 and p38 phosphorylation much more potently than that of Dasatinib. Furthermore, kinome profiling data indicate that AR4-13 also inhibits Mitogen-activated protein kinase (MAPK) kinase kinase kinases (MAP4Ks), which belong to a kinase family that controls the MAPK signaling in lymphoid cells. Consistently, RNAi-based synthetic lethal screen with TKIs show that suppression of MAP4Ks could significantly enhance the sensitivity to ABL TKIs in Ph+ B-ALL cells, implying that MAP4K family kinases function as a parallel pathway to BCR-ABL signaling and confer ABL TKI resistance in Ph+ B-ALL. Our findings indicate that simultaneous targeting both the ABL and MAP4K signaling pathways might serve as a promising TKI therapeutic strategy for Ph+ B-ALL.

Citation Format: Ruibao Ren, Xinhua Xiao, Jianming Zhang, Bo Jiao. Overriding drug resistance in Philadelphia chromosome-positive acute B lymphoblastic leukemia by targeting both BCR-ABL and MAP4K signaling pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 398.
Abstract 3982: Isolation, culture & characterization ofthe circulating tumor cells from breast cancer patients’ peripheral blood in vitro
Authors: Zhao Pan , Zhang Huirong , Liu Chang , Wang Jianhong , Zhou Wenbin , Zou Chang
Published: August 2019

Background: Circulating tumor cells (CTCs) are rare tumor cells in peripheral blood. As a few studies showed CTCs would be a kind of intriguing drug targets and more beneficial for cancer patients if there genomic and proteomic information could be deciphered dynamically. However, the rarity, challenging isolation as well as the primary culture procedures limited the analysis of CTCs insightfully.

Methods: The method of density gradient centrifugation was used to obtain PBMCs. Cells adherent and suspension culture for collecting the CTCs.

Results: There was a cell cluster which named CTC-3 came out in the plate. CTC-3 steadily formed clones, displayed epithelial phenotype and showed stem-cell like properties. Immunofluorescence identification of CTC-3 were DAPI-positive, Cytokeratin-positive, and CD45-negative. The karyotyping results indicated that chromosomes were aneuploidthe, the chromosome number of CTC-3 varied from 56 to 60. CTC-3 had larger nuclear/cytoplasmic ratio and limitless replicative potential. Comparing with the MCF-7, CTC-3 grew more faster than MCF-7 from the fifth day. Furthermore, the sphere formation ability of CTC-3 was significantly higher than MCF-7 in vitro. Besides, the tumorigenesis of CTC-3 cells was almost the same as MCF-7 in vivo by the analysis of xenografting in immunodeficient mice. For drug resistance, CTC-3 cells were more resistant to anti-tumor drugs after 3D culture compared with 2D, survive rates of 3D CTC-3 cells after treatment were more than 80%. Finally, the RT-PCR results shows the expression of Vimentin, E-cadherin and CD44 were significantly higher in CTC-3.

Conclusion: We have successfully isolated and expanted a new breast cancer cell line from the breast cancer patient, which could provide more drug sensitivity information of the patient and open up novel avenues towards the understanding of breast cancer.

Keywords: Circulating tumor cell; Breast cancer

Citation Format: Pan Zhao, Huirong Zhang, Chang Liu, Jianhong Wang, Wenbin Zhou, Chang Zou. Isolation, culture & characterization ofthe circulating tumor cells from breast cancer patients’ peripheral blood in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3982.
Abstract 3987: Predicting MCL1 inhibitor sensitivity in large cell line panels using a gene expression signature
Authors: Wernitznig Andreas , Rudolph Dorothea , Samwer Matthias , Schweifer Norbert , Trapani Francesca , Wunberg Tobias , Arnhof Heribert , Lee Teakyu , Sensintaffar John L. , Olejniczak Edward T. , Benes Cyril H. , Fesik Stephen W. , Kraut Norbert
Published: August 2019

MCL1, an anti-apoptotic member of the BCL-2 family of proteins, is a key regulator of cancer cell survival and a known resistance factor to anti-cancer drugs, making it a highly desirable target for therapeutic intervention. Recently several MCL1 inhibitors have entered Phase I clinical development. Data derived from large cancer cell line panels suggest, that cell lines of hematopoietic origin are more broadly sensitive to MCL1 inhibition, than cell lines derived from solid tumor types. In particular, for the therapy of solid tumor patients with an MCL1 inhibitor, a patient selection biomarker would be highly desirable.

Published in vitro data using various MCL1 inhibitors, siRNA or CRISPR/Cas9 technology show that tumor cell lines with low BCL-XL gene expression are mostly sensitive to MCL1 inhibition, down-regulation or inactivation. Here we show that by adding the gene expression data of additional six genes (including the MCL1 binding partner BAK1) to BCL-XL, a supervised learning predictor was applied and could reach a performance of almost 80% correctly classified solid tumor cell lines. This new predictor has been applied to either tumor samples, adjacent normal tissues or normal tissue samples from TCGA and GTEx. Briefly, most normal tissue samples are categorized as being sensitive. Moreover, solid tumor samples in contrast to solid tumor cell lines are predicted to be broadly sensitive to MCL1 inhibition with a predicted anti-tumor effect rate of 60% to 95%. In summary, our work describes the translational challenges using cell line-derived predictors on ex vivo tumor samples.

Citation Format: Andreas Wernitznig, Dorothea Rudolph, Matthias Samwer, Norbert Schweifer, Francesca Trapani, Tobias Wunberg, Heribert Arnhof, Teakyu Lee, John L. Sensintaffar, Edward T. Olejniczak, Cyril H. Benes, Stephen W. Fesik, Norbert Kraut. Predicting MCL1 inhibitor sensitivity in large cell line panels using a gene expression signature [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3987.
Abstract 3988: Identifying prognostic biomarkers of hepatocellular carcinoma by weighted gene coexpression network analysis
Authors: Bai Yi , Long Junyu , Lin Jianzhen , Yang Xu , Wang Dongxu , Yang Xiaobo , Sang Xinting , Liu Jiahui , Zhao Haitao
Published: August 2019

Purpose: Exploring the molecular mechanisms of prognosis in patients with hepatocellular carcinoma (HCC) could assist in identifying novel biomarkers for effective therapy against this deadly disease. Hence, this study was designed to determine the prognostic biomarkers of HCC and to investigate potential mechanisms. Experimental Design: The RNA-Seq data as well as clinical data were downloaded from The Cancer Genome Atlas (TCGA) database, aiming at identifying differentially expressed genes (DEGs) between nontumorous tissues and HCC. Then, weighted gene coexpression network analysis (WGCNA) was performed for determining significant modules associated with overall survival (OS). Results: The mRNA expression profiles from 374 HCC patients in TCGA were included to determine 3270 DEGs. Then, WGCNA was carried out on the 3270 DEGs, and 10 coexpressed gene modules were determined. Pearson’s correlation analysis revealed that the turquoise module significantly positively correlated with OS and the blue module significantly negatively correlated with OS, followed by seven hub genes with high connectivity were identified in these two modules. Based on the Kaplan-Meier (K-M) survival curves and receiver operating characteristic (ROC) curves, the seven hub genes could predict prognosis for patients with HCC well, and the results were validated by GSE54236 dataset contained 78 HCC patients. Additionally, the univariate and multivariate Cox regression analyses showed that the seven hub genes were independent prognostic factors for patients with HCC. Conclusions: In conclusion, the current results provide novel insights into the prognostic biomarkers of HCC, which may contribute to the development of molecular targeted therapy for HCC.

Citation Format: Yi Bai, Junyu Long, Jianzhen Lin, Xu Yang, Dongxu Wang, Xiaobo Yang, Xinting Sang, Jiahui Liu, Haitao Zhao. Identifying prognostic biomarkers of hepatocellular carcinoma by weighted gene coexpression network analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3988.
Abstract 3989: Identification of biomarkers for UM-164 in triple-negative breast cancer
Authors: Merrill Nathan M. , Vandecan Nathalie M. , Lloyd John P. , Lachacz Eric J. , Ulintz Peter J. , Merajver Sofia D. , Soellner Matthew B.
Published: August 2019

Triple negative breast cancer (TNBC) is one of the deadliest forms of breast cancer due to limited treatment options beyond conventional chemotherapy. While making up approximately 10-20% of total breast cancer cases in the US, TNBC carries a serious burden of disease as it tends to be more aggressive, higher grade, and have a poorer prognosis than other forms of breast cancer. Though new therapies, such as PARP inhibitors, have shown promise in clinical trials in very select patients (e.g. BRCA1 mutation carriers), there is a general lack of predictive markers of therapeutic efficacy to identify subsets of patients most likely to positively respond to a given targeted or conventional therapy. Thus, there is a critical need for biomarkers of drug efficacy in TNBC to help design precision medicine clinical trials based on systematically derived predictive biomarkers. To fill this gap, we devised a strategy to identify biomarkers of drug efficacy in TNBC. As a paradigm of our approach, we treated a panel of 23 TNBC cell lines with our potent c-Src/p38 inhibitor, UM-164, and determined a drug sensitivity score (DSS) in each line. We then calculated correlations of DSS with a variety of molecular readouts, including RNA sequencing, reverse-phase protein array, DNA sequencing array, and Nanostring RNA and miRNA arrays. From these correlations, we have identified expression DJ1, MAPK11, and PCM1 as strong predictors of UM-164 efficacy in TNBC. Building on this, we used our results to identify companion drugs that lead to synergy or test others that could instead result in antagonism when used in combination. To verify our results, independently targeting the DJ1 pathway, we show that AKT inhibition results in synergy when combined with UM-164. The outcome of this research yields a robust and generalizable methodology for the identification of biomarkers in cancer to design Phase I-III trials and for generating the mechanistic evidence of effective rational combinations.

Citation Format: Nathan M. Merrill, Nathalie M. Vandecan, John P. Lloyd, Eric J. Lachacz, Peter J. Ulintz, Sofia D. Merajver, Matthew B. Soellner. Identification of biomarkers for UM-164 in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3989.