bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1277: Honokiol, a natural product, overcomes acquired resistance of EGFR mutant NSCLC cells to the third generation EGFR inhibitor, osimertinib
Authors: ZANG Hongjing , Fan Songqing , Arbiser Jack , Owonikoko Taofeek K. , Ramalingam Suresh S. , Sun Shi-Yong
Published: August 2019

Osimertinib (AZD9291) is a FDA-approved EGFR inhibitor for treating non-small cell lung cancer (NSCLC) patients with activating EGFR mutations (first-line) or those who have become resistant to 1st generation EGFR inhibitors through the T790M mutation (second-line). The development of acquired resistance to osimertinib limits the long-term benefits of patients, and effective treatment options are urgently needed. We have identified that honokiol, a natural product with potential antitumor activity, may be used to overcome osimertinib resistance. In several osimertinib-resistant cell lines including HCC827/AR, PC-9/AR, PC-9/GR/AR and PC-9/3M (with EGFR 19del, T790M and C797S mutations), the combination of honokiol and osimertinib had synergistic effects on decreasing the survival of these cell lines. The combination inhibited cell colony formation and growth, and augmented induction of apoptosis of resistant cells. This combination enhanced reduction of Mcl-1, a critical mechanism by which osimertinib induces apoptosis in sensitive EGFR mutant NSCLC cells; this effect is likely due to enhanced Mcl-1 degradation since Mcl-1 was degraded much faster in cells exposed to the combination of honokiol and osimertinib than in DMSO-treated control cells. Moreover enforced overexpression of ectopic Mcl-1 abolished the enhanced effect of honokiol and osimertinib combination on induction of apoptosis, supporting a critical role of Mcl-1 reduction in inducing apoptosis of the osimertinib-resistant cells by this combination. Our findings warrant further study of this combination for overcoming osimertinib-resistance in vivo and potentially in the clinic. (This work was supported by the NIH/NCI R01 CA223220 to SYS and Winship lung cancer pilot award to SYS).

Citation Format: Hongjing ZANG, Songqing Fan, Jack Arbiser, Taofeek K. Owonikoko, Suresh S. Ramalingam, Shi-Yong Sun. Honokiol, a natural product, overcomes acquired resistance of EGFR mutant NSCLC cells to the third generation EGFR inhibitor, osimertinib [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 1277.
Abstract 1280: Positive PD-L1 expression is associated with unfavorable clinical outcome in EGFR-mutated lung adenocarcinomas treated with EGFR-TKIs
Authors: Lee Seung Hyeun , Park Myung Jae , Chang Boksoon
Published: August 2019

Objectives: Clinical implication of programmed death ligand 1 (PD-L1) expression in oncogene-addicted non-small cell lung cancer treated with tyrosine kinase inhibitors (TKIs) is largely unknown. The objective of this study was to determine the frequency of PD-L1 expression and the clinical outcome according to PD-L1 expression in lung adenocarcinomas harboring EGFR mutation and treated with EGFR-TKIs.

Methods: We retrospectively evaluated PD-L1 expression using 22C3 pharmDx assay in lung adenocarcinoma patients with EGFR mutations at two referral hospitals between January 2017 and June 2018. Samples were obtained from surgically resected tumors, small biopsy, or cytologic cell blocks.

Results: Of all 71 patients analyzed, 44 (58.7%) had PD-L1 tumor proportion score (TPS) of < 1%, 23 (30.7%) had PD-L1 TPS of 1%-49%, and 8 (10.7%) had PD-L1 TPS of ≥ 50%. Of the 37 patients treated with first-line EGFR-TKIs, PD-L1 TPS ≥ 1% was associated with a significantly decreased response rate, compared with PD-L1 TPS < 1% (45.7% vs. 67.3%, p=0.005). Furthermore, PD-L1 TPS ≥ 1% was associated with a significantly shorter median progression free survival, compared with PD-L1 TPS < 1% (9.3 months vs. 14.2 months, p = 0.024). Multivariate analysis showed that PD-L1 TPS ≥1% is independently associated with shorter PFS (hazard ratio 1.32, p=0.012).

Conclusion: PD-L1 was positive in approximately 40% of patients with EGFR-mutated lung adenocarcinoma. Postive PD-L1 expression may be associated with unfavorable clinical outcome to EGFR-TKIs among those patients group.

Citation Format: Seung Hyeun Lee, Myung Jae Park, Boksoon Chang. Positive PD-L1 expression is associated with unfavorable clinical outcome in EGFR-mutated lung adenocarcinomas treated with EGFR-TKIs [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 1280.
Abstract 1285A: Erythropoietin can cancelchemo-resistances viadown regulation of ABC transporters
Authors: Matsui Hirofumi , Kurokawa Hiromi
Published: August 2019

Introduction: Erythropoietin (EPO) is a glycoprotein cytokine which stimulates red blood cell production (erythropoiesis) in the bone marrow. The receptor of it (EPOR) was reported to exist on the cancer cellular membrane: more than 85% cancer cell expresses EPOR. Several reports suggested to play an important role for cancer cellular growth, however, the role of EPOR in cancer cells is not confirmed. The authors have studied the cancer cellular porphyrin accumulation, metabolism and excretion to clear the pathogenetic mechanism which involved the high concentration of porphyrins. The authors found that reactive oxygen species (ROS) accelerate both the cancer cellular porphyrin accumulation and the effect of photodynamic therapy. However, we cannot confirm which substrate is a key of signal transduction. EPO has been known used to be up-regulated at the metabolic acidosis via the stabilization of HIF-1α, a nuclear factor. Since HIF-1α can be stabilized by not only acidosis but also the high concentration of nitric oxide (NO), NO rich cancer cells may involve EPOR. Moreover, the purpose of EPO-EPOR system is likely to survive the hypoxic condition, it may keep intracellular heme/ porphyrins. The authors’ hypothesis is EPO-EPOR system in cancer cells may down-regulate ABCG2 which excretes heme/ porphyrins, and several anti-cancer drugs. Moreover, if so, the excretion of several anti-cancer chemo reagents should be inhibited to involve more effective chemotherapy.

Methods: To prove these possibilities, the authors carry out following experiments with gastric and colorectal cancer cells. The existence of EPOR, the amount of ABC transporters (B1, C5, G2) after the recombinant EPO (rEPO) exposure (dose dependency and time dependency) were analyzed by western blotting. Cytotoxicity of anti-cancer drugs with or without rEPO was measured with the Cell Counting Kit-8.

Result: (1) EPOR existed in each cell line used in this study. (2) rEPO treatment involved down regulation of ABC transporters (B1, C5, G2) in dose dependently. (3) ABCG2 expression decreased until 24 hours after rEPO treatment. However, its expression re-increased 48 hours after treatment. (4) The 24 hours pretreatment of EPO significantly increased the effect of doxorubicin, paclitaxel, irrinotecan, cisplatin, 5-FU and oxaliplatin even in chemo-resistant cells.

Conclusions: rEPO accelerates the effect of anti-cancer drugs via the down regulation of ABC transporters.

Citation Format: Hirofumi Matsui, Hiromi Kurokawa. Erythropoietin can cancelchemo-resistances viadown regulation of ABC transporters [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 1285A.
Abstract 1300: Novel thyrointegrin αvβ3 antagonist in the treatment of glioblastoma multiforme
Authors: Mousa Shaker A. , Sudha Thangirala , Godugu Kavitha , Rajabi Mehdi , Sell Stewart , Davis Paul J.
Published: August 2019

Background: The proliferative and pro-angiogenic actions mediated by L-thyroxine, pro-inflammatory and all known growth factors in glioblastoma multiforme (GBM) are initiated at cell surface thyrointegrin αvβ3 receptors for thyroid hormone on the extracellular domain of integrin αvβ3. Thyrointegrin αvβ3 receptors are over-expressed on cancer and rapidly dividing blood vessel cells, but quiescent on normal cells. A macromolecule Polyethylene glycol-conjugated bi-TriAzole Tetraiodothyroacetic acid (P-bi-TAT) acts with high affinity (Ki 3.1 nM) and specificity for the thyrointegrin αvβ3 receptors without any significant nuclear translocation.

Methods: In the present studies, three primary human GBM cells and U87 glioma cell line were implanted orthotopically or subcutaneously (s.c.) into nude mice that were treated daily for up to 21 days with P-bi-TAT at different doses. Additionally, preclinical Pharmacokinetic and Safety assessments were carried out in multiple species.

Results: Pharmacokinetic profiles indicated once-a-day dosing, and safety assessment studies demonstrated high safety and tolerability at 100-fold over the anticipated human equivalent dose. Fluorescence labeled P-bi-TAT administered s.c. demonstrated high biodistribution to GBM tumor in the brain that was comparable to peripherally implanted tumor. P-bi-TAT administered daily for 10-21 days s.c. at 0.3-10 mg/kg resulted in a dose-dependent suppression of GBM tumor growth and viability monitored with IVIS imaging (p <0.001). Histopathological analysis of tumors revealed 95% loss of the vascularity of treated tumors at 10 days (p <0.001) along with extensive cellular necrosis and apoptosis, without intratumoral hemorrhage. GBM tumors had a 97% volume loss and maximal loss of GBM cell viability during a subsequent 22 days off-treatment period (p < 0.001). Genomic micro-array studies with human primary GBM revealed that over 30 pathways relevant to the progression of GBM are modulated by P-bi-TAT.

Conclusions: P-bi-TAT is a promising lead clinical candidate effective in the treatment of human GBM.

Citation Format: Shaker A. Mousa, Thangirala Sudha, Kavitha Godugu, Mehdi Rajabi, Stewart Sell, Paul J. Davis. Novel thyrointegrin αvβ3 antagonist in the treatment of glioblastoma multiforme [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 1300.
Abstract 1302: Targeting hormone receptor-dependent cancers with potent, selective and orally-available small molecule inhibitors of eIF4E
Authors: Chiang Gary G. , Parker Gregory S. , Hung Ivy N. , Goel Vikas K. , Staunton Jocelyn , Barrera Maria , Sung Eric , Parra Ana , Stumpf Craig R. , Chen Joan , Thompson Peggy A. , Nevarez Andreas , Wegerski Christopher J. , Parker Cody , Clarine Jeff , Sperry Samuel , Xiang Alan , Nilewski Christian , Packard Garrick K. , Urkalan Kaveri , Mukaiyama Takasuke , Michels Theo , Ernst Justin T. , Sprengeler Paul A. , Reich Siegfried H. , Webster Kevin R.
Published: August 2019

The PI3K/mTOR pathway is commonly dysregulated in many hormone receptor-dependent tumors and plays a key role in promoting tumor growth and mediating drug resistance. In particular, PI3K and mTORC1/2 inhibitors have been intensively studied in the treatment of hormone receptor-dependent cancers and have shown benefit in some clinical settings. However, issues such as dose-limiting toxicities and emergent resistance limit the broader utility of these inhibitors. The translation initiation factor eIF4E is essential for the translation of m7G-capped mRNA and is a key point of convergence for both the PI3K/mTOR and MAPK signaling pathways. We have designed a series of potent, selective and orally-available m7G cap-competitive inhibitors of eIF4E (eFT-4Ei) with favorable drug-like properties. These inhibitors bind to eIF4E either as its free form or with eIF4E-4EBP and eIF4F complexes within tumor cells and downregulate hormone receptor-dependent signaling. Ribosomal profiling of eIF4E inhibitor-treated tumor cells identified a subset of translationally regulated target genes that overlap with mTORC1/2 regulated genes, but also a unique set of translationally regulated target mRNAs. Consistent with this observation, our eIF4E inhibitors show some similarities yet several important differences from existing mTORC1 or mTORC1/2 dual inhibitors in both cellular and physiological assays. Finally, significant anti-tumor efficacy was observed with eIF4E inhibition in vitro and in vivo. Taken together, these results highlight the potential for targeting eIF4E as a novel therapeutic strategy to treat hormone-receptor dependent cancers.

Citation Format: Gary G. Chiang, Gregory S. Parker, Ivy N. Hung, Vikas K. Goel, Jocelyn Staunton, Maria Barrera, Eric Sung, Ana Parra, Craig R. Stumpf, Joan Chen, Peggy A. Thompson, Andreas Nevarez, Christopher J. Wegerski, Cody Parker, Jeff Clarine, Samuel Sperry, Alan Xiang, Christian Nilewski, Garrick K. Packard, Kaveri Urkalan, Takasuke Mukaiyama, Theo Michels, Justin T. Ernst, Paul A. Sprengeler, Siegfried H. Reich, Kevin R. Webster. Targeting hormone receptor-dependent cancers with potent, selective and orally-available small molecule inhibitors of eIF4E [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 1302.
Abstract 1304: Aryl hydrocarbon receptor ligands 5F 203 and 3,3'-Diindolylmethane disrupt mammospheres derived from MCF-7 cells and induce tumor suppressor miR125b-2 expression
Authors: Brantley Eileen , Mavingire Nicole , Wooten Jonathan , Campbell Petreena
Published: August 2019

While anti-estrogen tamoxifen (Tam) effectively treats many patients with estrogen receptor positive (ER+) tumors, up to 40% experience relapse following resistance. Breast cancer stem cells (CSCs) within tumors greatly contribute to tamoxifen resistance (TamR) and exhibit unique molecular signatures that drive metastasis and promote relapse. Tumor suppressor miRNAs aid in suppressing breast cancer progression. We have previously shown that aryl hydrocarbon receptor (AhR)-ligand Aminoflavone disrupts the formation of spheres and inhibits the expression of putative stemness marker α6-integrin and α6-integrin-src-Akt signaling. We hypothesize that two AhR ligands, 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) and 3,3'-Diindolylmethane (DIM), exhibit anticancer properties in MCF-7 breast cancer cells by targeting the CSC population in an AhR-dependent fashion. We found that DIM and 5F 203 disrupted mammospheres derived from MCF-7 cells but demonstrated a reduced capacity to do so in mammospheres derived from AHR100 cells (MCF-7 variants that are AhR-unresponsive). Wound healing and colony forming assays respectively revealed that 5F 203 and DIM also decreased cell migration and cell proliferation in MCF-7 cells and to a much lesser extent in AhR100 cells. 5F 203 and DIM induced miR125b-2 expression and suppressed the expression of stemness-regulating genes such as α6-integrin, a predicted miR125b-2 target. The reduction in stemness-gene expression in MCF-7 cells was attenuated following pretreatment with AhR antagonist CH223191. These data suggest that AhR ligands such as DIM and 5F 203 confer their anticancer actions including those against breast CSCs in an AhR-dependent manner. Our data is expected to provide a rationale for the development of anticancer AhR ligands designed to combat ER+ breast cancer and decrease the risk of relapse.

Citation Format: Eileen Brantley, Nicole Mavingire, Jonathan Wooten, Petreena Campbell. Aryl hydrocarbon receptor ligands 5F 203 and 3,3'-Diindolylmethane disrupt mammospheres derived from MCF-7 cells and induce tumor suppressor miR125b-2 expression [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 1304.
Abstract 1305: Identification of signal transduction kinases inhibited by pan-RAF inhibitor belvarafenib using FRET imaging technique
Authors: Bae Dong-Jun , Kim Sang-Yeob , Byun JooYun , Bae InHwan , Ahn YoungGil , Kim YoungHoon , Suh Kwee Hyun
Published: August 2019

The mitogen-activated protein kinase (MAPK) pathway plays an important role for the survival and proliferation of tumor cells. For example, the activation of the MAPK pathway due to mutations in BRAF, NRAS and KRAS kinases is known to be the causes of various solid tumors and hematologic malignancies. Accordingly, there is a strong need for effective therapeutic drugs for treating cancers caused by genetic mutation of BRAF, NRAS or KRAS. Belvarafenib (HM95573 or GDC5573), currently in Phase 1 clinical trials, is a selective and orally bioavailable pan-RAF kinase inhibitor. When biochemically assayed for hundreds of kinases, Belvarafenib showed selectivity toward RAF family kinases, including strong inhibition activities for BRAF WT, BRAF mutants and CRAF. Previously, we reported that Belvarafenib strongly inhibits the growth of cancer cell lines with BRAF, NRAS or KRAS mutations and also shows excellent anticancer efficacy in animal models using the corresponding cancer cells. In this study, employing fluorescence resonance energy transfer (FRET) imaging, we examined which protein kinases involved in signal transduction are regulated by Belvarafenib and investigated the mechanism of action for the regulation in typical cancer cells harboring BRAF, NRAS or KRAS mutations such as A375 (melamona), SK-MEL-30 (Kwmelamona), HCT116 (CRC), and Calu-6 (NSCLC). Among the various protein kinases that can be involved in signal transduction, we identified with time-lapse FRET imaging that the phosphorylation of ERK, AKT and S6K are inhibited after the treatment of Belvarafenib in the above cancer cells of BRAF, NRAS or KRAS mutations. Of note, BRAF mutant selective inhibitors, Vemurafenib and Dabrafenib were not active in cancer cells of NRAS or KRAS mutations. These results correlate with the in vitro and in vivo anticancer activity in cancer cells of BRAF, NRAS or KRAS mutations. In conclusion, unlike Vemurafenib and Dabrafenib, the pan-RAF inhibitor Belvarafenib could be effective for treating the cancer caused by NRAS or KRAS mutations, as well as BRAF mutations.

Citation Format: Dong-Jun Bae, Sang-Yeob Kim, JooYun Byun, InHwan Bae, YoungGil Ahn, YoungHoon Kim, Kwee Hyun Suh. Identification of signal transduction kinases inhibited by pan-RAF inhibitor belvarafenib using FRET imaging technique [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 1305.
Abstract 1309: Targeting GluN2C ion channels as a promising approach in the treatment of melanoma
Authors: Tabatabaee Hessam , Feng Yuchen , Yari Hamed , La Ting , Sherwin Simonne , Jin Lei , Lim Rebecca , Brichta Alan , Zhang Xu Dong
Published: August 2019

Ion channels are pore-forming integral membrane proteins that are known to have an impact on all hallmarks of cancer. Due to their expression on the surface of the cells, ion channels provide a distinct therapeutic target with more facilitated access from the extracellular milieu. NMDA receptors are a subtype of ligand-gated ion channels that express unique features including high calcium permeability as well as the requirement for binding of glutamate and the co-agonist glycine in order to be activated. Here we show that a glutamate ionotropic NMDA (N-methyl-D-aspartate) type ion channel, GluN2C is critically required for survival of human melanoma cells. Publicly available microarray data from Gene Expression Omnibus (GEO) were acquired in order to identify the differentially expressed ion channel genes in 127 melanoma patient samples relative to benign nevi or human epidermal melanocytes. Data exists into two major cohorts: First cohort consisted of 18 benign nevi and 45 melanoma (GSE3189), while second cohort contained 8 melanocytes and 82 melanoma (GSE29377). A bioinformatics approach was undertaken to determine commonly upregulated ion channels between the two cohorts. Subsequently, functional enrichment analysis along with pathway evaluation of these genes revealed GluN2C as a novel candidate for further investigation in this study. Upregulation of GluN2C was confirmed in a panel of melanoma cell lines and fresh melanoma isolates. Strikingly, silencing of GluN2C markedly reduced viability and clonogenicity in melanoma cells. Consistently, a pharmacological inhibitor of GluN2C potently killed melanoma cells with minimal effects on melanocytes and fibroblasts. Killing of melanoma cells by inhibition of GluN2C was not due to induction of apoptosis, since a general caspase inhibitor Z-VAD-FMK failed to rescue cells from dying. In contrast, the late stage autophagy inhibitor Bafilomycin A1 blocked the GluN2C induced cell death suggesting that killing of melanoma cells following inhibition of GluN2C is in part associated with induction of autophagy. Collectively, these results uncover a potential role for GluN2C ion channels in the pathogenesis of melanoma and suggest that these ion channels may constitute a promising target for melanoma treatment.

Citation Format: Hessam Tabatabaee, Yuchen Feng, Hamed Yari, Ting La, Simonne Sherwin, Lei Jin, Rebecca Lim, Alan Brichta, Xu Dong Zhang. Targeting GluN2C ion channels as a promising approach in the treatment of melanoma [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 1309.
Abstract 1321: TPX-0022, a polypharmacology inhibitor of MET/CSF1R/SRC for treatment of cancers with abnormal HGF/MET signaling
Authors: Zhai Dayong , Rogers Evan , Deng Wei , Zhang Xin , Lee Dong , Ung Jane , Zhang Han , Liu Jing , Lu Yuelie , Huang John , Graber Armin , Zimmerman Zach , Lim John , Whitten Jeffrey , Cui J. Jean
Published: August 2019

Aberrant activation of the HGF/MET pathway has frequently been found in human cancers via MET mutation, gene amplification and translocation, as well as HGF paracrine or autocrine upregulation. The abnormal HGF/MET signaling not only acts as an oncogenic driver but also confers resistance to many cancer therapies, such as EGFR targeted therapy in NSCLC. One key downstream effector for activated MET is SRC, which is also involved in malignancy formation, tumor metastasis and drug resistance. In the tumor microenvironment, CSF1R plays an important role in regulation of tumor associated macrophages, which promote tumor progression and angiogenesis. Therefore, the polypharmacological inhibition of MET/SRC/CSF1R has great potential for more effectively targeting cancers with abnormal HGF/MET signaling via targeting both tumor intrinsic signaling and the tumor microenvironment. TPX-0022, a novel macrocyclic compound, has been designed and optimized to inhibit MET/CSF1R/SRC with enzymatic kinase inhibition IC50s of 0.14, 0.76 and 0.12 nM, respectively. TPX-0022 potently inhibited cell proliferation of the MET-amplified MKN-45 and SNU-5 gastric cancer cells, with IC50s <0.2 nM, which ranked TPX-0022 as one of the most potent MET inhibitors. TPX-0022 caused suppression of MET auto-phosphorylation at an IC50 of approximately 0.3 nM in MKN-45 cell line. TPX-0022 also potently inhibited the phosphorylation of MET downstream signaling effectors, including AKT, ERK, STAT3 and PLCγ2 in a dose-dependent manner. In the cancer cell line- and patient-derived xenograft tumor models from gastric, lung and liver cancers harboring MET amplification or MET exon14 skipping mutations, TPX-0022 caused dramatic tumor regression and tumor growth inhibition, without overt abnormality and body weight loss in treated mice. Furthermore, the tumor inhibitory effect was associated with drastic inhibition of MET activity. Overall, TPX-0022 is a novel and potent MET inhibitor and has demonstrated desirable drug-like properties, a good preclinical safety profiles, that warrants further clinical development and an IND submission is currently planned.

Citation Format: Dayong Zhai, Evan Rogers, Wei Deng, Xin Zhang, Dong Lee, Jane Ung, Han Zhang, Jing Liu, Yuelie Lu, John Huang, Armin Graber, Zach Zimmerman, John Lim, Jeffrey Whitten, J. Jean Cui. TPX-0022, a polypharmacology inhibitor of MET/CSF1R/SRC for treatment of cancers with abnormal HGF/MET signaling [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 1321.
Abstract 1328: Exploring the pharmacokinetic-pharmacodynamic relationships of AZD3229, a novel and selective inhibitor of cKIT, in a range of mouse xenograft models of gastrointestinal stromal tumors
Authors: Reddy Venkatesh Pilla , Smith Aaron , Grondine Michael , Anjum Rana , Jones Rhys D.
Published: August 2019

cKIT belongs a family of transmembrane tyrosine kinase growth factor receptors and gain of function mutations result in constitutive c-KIT activation that provide an important pathogenic role in gastrointestinal stromal tumors (GIST). AZD3229 is a highly potent and selective oral best-in-class KIT inhibitor that is active against a wide spectrum of primary and secondary KIT mutations that are known to confer resistance to standard of care agents. AZD3229 demonstrates rapid, extensive and sustained inhibition of KIT signaling in preclinical xenograft models with KIT primary exon 11 del mutations and primary/secondary ATP-binding pocket mutations (GIST 430/654A and patient-derived xenograft (PDX) model of KIT V654A, HGiXF-106) and A-loop mutations (PDX model of KIT Y823D, HGiXF-105 and Ba/F3 KIT D816H). In these models, AZD3229 results in anti-tumour activity (tumour regressions ranging from -60% to -99 % TGI) when dosed orally up to 20 mg/kg BID.

The objective of this PK-PD modeling work was to (1) establish the PK-PD-Efficacy relationship for AZD3229 across the four cell-lines and PDX mouse models tested; (2) to confirm the extent and duration of pKIT inhibition required for optimal efficacy, as defined by tumor regressions.

Inhibition of KIT phosphorylation observed with AZD3229 shows a direct relationship to free mouse plasma concentration and an estimated in vivo EC90 was estimated for each model (Ba/F3 D816H = 20 nM; GIST 430/V654A= 43 nM; HGiX-106 = 76 nM; HGiX-105 = 4 nM). No change in the extent of inhibition of KIT phosphorylation was observed on repeat dosing. Optimal efficacy is observed when sustained inhibition of pKIT, >90% is achieved over the dosing interval.

Conclusion: Exploring the in vivo activity and PK-PD relationship in multiple cell-line derived xenograft and PDX models harboring different mutations provides a benchmark from which to anchor human dose predictions that partly reflect the spectrum of responses likely to be seen in GIST patients.

Citation Format: Venkatesh Pilla Reddy, Aaron Smith, Michael Grondine, Rana Anjum, Rhys D. Jones. Exploring the pharmacokinetic-pharmacodynamic relationships of AZD3229, a novel and selective inhibitor of cKIT, in a range of mouse xenograft models of gastrointestinal stromal tumors [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 1328.
Abstract 133: The role of the calcium-sensing receptor (CaSR) in the adaptation of breast cancer cells in high Ca2+ microenvironments
Authors: Beasley Heather K. , Actkins Ky'Era V. , Widatalla Sarrah E. , Whalen Diva S. , Williams Stephen D. , Korolkova Olga Y. , Sakwe Amos M.
Published: August 2019

Cancer-induced hypercalcemia (CIH) is common in cancer patients with metastatic disease and in up to 30% of cases without metastasis. During malignancy, tumor cells secrete factors such as parathyroid hormone related protein (PTHrP) that causes the destruction of bone tissue, or osteolysis. The resulting persistent osteolysis leads to a progressive increase in systemic calcium or CIH. High circulating Ca2+ is sensed by the calcium-sensing receptor (CaSR), which plays a significant role in maintaining Ca2+ homeostasis, and also stimulates the secretion of PTHrP which promotes tumor cell proliferation and motility. Moreover, more than 200 mutations including single nucleotide polymorphisms (SNPs) in the CaSR gene have been described, including the inactivating A986S CaSR at rs1801725 and Q1011E CaSR at rs1801726 SNPs with reduced sensitivity to Ca2+ . Although the CaSR is the major cell surface Ca2+ sensor in most cell types, its function in the Ca2+ rich bone microenvironment remains unclear. We show that high Ca2+ adaptation of MDA-MB-231 cells, did not lead to altered expression of the receptor in the surviving cells. However, the receptor was desensitized to high Ca2+ and the cells were more motile and formed larger colonies in 3D cultures. Meanwhile, gene expression profiling of triple negative breast cancer cells (TNBC) cells transiently exposed to high Ca2+ reveals the expression of early response genes and Ca2+ -inducible genes with known functions in tumor growth and/or motility. Since breast cancer (BC) frequently metastasizes to skeletal tissues, these data suggest that BC cells that successfully colonize the bone microenvironment undergo high Ca2+ adaptation or priming via the expression of high Ca2+ inducible genes that facilitate cell growth and/or motility.

Citation Format: Heather K. Beasley, Ky'Era V. Actkins, Sarrah E. Widatalla, Diva S. Whalen, Stephen D. Williams, Olga Y. Korolkova, Amos M. Sakwe. The role of the calcium-sensing receptor (CaSR) in the adaptation of breast cancer cells in high Ca2+ microenvironments [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 133.
Abstract 1343: SNPs in the NFKB alternative pathway genes CD40, BAFFR and LTβR in CRC
Authors: Antonacopoulou Anna , Kottorou Anastasia , Koutras Angelos , Dimitrakopoulos Foteinos-Ioannis , Makatsoris Thomas , Kalofonos Haralabos P.
Published: August 2019

We sought to assess the role of single nucleotide polymorphisms (SNPs) in genes of the alternative NF-KB pathway, important in regulating different aspects of immune functions in colorectal cancer (CRC). The study comprised DNA samples from 418 patients with CRC and 299 age-matched healthy individuals. Genotyping was performed with real time PCR followed by high resolution melt curve analysis for the following SNPs: CD40 rs1883832 (C/T), BAFFR rs7290134 (A/G), LTβR rs10849448 (A/G). Genotypes of random samples were confirmed by sequencing. Genotype frequencies differed between CRC and healthy individuals for CD40 rs1883832 and LTβR rs10849448 (p = 0.001 and p = 0.016, respectively) but were similar for BAFFR rs7290134. The LTβR rs10849448 G allele was more frequent in CRC patients compared to healthy controls and increased risk for CRC by 61% (p = 0.024). Moreover, the G allele was found more frequently in stage D patients compared to stages A and C while the A allele was more prevalent in stage B patients (p = 0.007). Additionally, most patients with grade III tumors were G allele carriers whereas the majority of grade I tumors were AA homozygotes (p = 0.019). The CD40 rs1883832 T allele was less frequent in CRC patients and reduced risk for CRC by 71% (p = 0.027). The CD40 rs1883832 SNP proved to be a prognostic factor for PFS with the CC individuals displaying a longer PFS compared to T carriers (p = 0.045). The BAFFR rs7290134 SNP was independent of all clinical parameters evaluated. Primary site was independent of genotypes for all three SNPs. SNPs within genes of receptors of the NF-KB alternative pathway, CD40 rs1883832 and LTβR rs10849448, influence PFS and risk for CRC development. Additionally, particular genotypes correlated with stage and grade.

Citation Format: Anna Antonacopoulou, Anastasia Kottorou, Angelos Koutras, Foteinos-Ioannis Dimitrakopoulos, Thomas Makatsoris, Haralabos P. Kalofonos. SNPs in the NFKB alternative pathway genes CD40, BAFFR and LTβR in CRC [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 1343.
Abstract 1345: Automated capture and analysis of circulating tumor cells across different types of tumors in pediatric cancer patients
Authors: Batth Izhar S. , Zaky Wafik , Khatua Soumen , Daw Najat C. , Mahadeo Kris M. , Khazal Sajad , Albert Aisha , Huang Wilber , Chen Diva , Gill Jonathan B. , Kleinerman Eugenie , Gorlick Richard , Li Shulin
Published: August 2019

The clinical utility of blood analysis such as circulating tumor cells (CTCs) has garnered increasing interest in recent years. However very few studies were conducted in pediatric cancer patients especially in brain tumor, osteosarcoma, and leukemia patients due to the lack of an effective tool to isolate/capture CTC from these patients. For example, only three independent studies were published to investigate CTC capture from adult brain tumor patients but zero studies were conducted with pediatric brain cancer patients. Our previous studies showed the high specificity of using cell surface vimentin (CSV) to identify and capture CTCs from various types of adult tumor patients using a manual isolation method. Here we present the first automated system for capturing CTCs across different types of pediatric tumors. This automated system utilizes the Abnova CytoQuest system loaded with the CSV antibody 84-1-coated microfluidic cassette for capturing CTCs from peripheral blood samples. This automated assay was very sensitive because as few as one tumor cell can be captured out from one million normal cells. Based on our preliminary study, our success rate for non-DIPG brain tumor, ALL, and AML patients is 100%. This success provides a potential opportunity for analyzing brain tumor genetic properties using blood samples instead of the invasive tumor biopsy; likewise, this high sensitivity assay opens up clinical opportunities to use this assay for transplant and treatment decision making.

Note: This abstract was not presented at the meeting.

Citation Format: Izhar S. Batth, Wafik Zaky, Soumen Khatua, Najat C. Daw, Kris M. Mahadeo, Sajad Khazal, Aisha Albert, Wilber Huang, Diva Chen, Jonathan B. Gill, Eugenie Kleinerman, Richard Gorlick, Shulin Li. Automated capture and analysis of circulating tumor cells across different types of tumors in pediatric cancer patients [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 1345.
Abstract 1349: Personalized circulating tumor DNA profiling in malignant pleural mesothelioma
Authors: Martinson Luke J. , Sharkey Annabel J. , Dawson Alan G. , Hastings Robert K. , Wilson Gareth , Waller David , Nakas Apostolos , Swanton Charles , Shaw Jacqui A. , Fennell Dean A.
Published: August 2019

Background:

Malignant pleural mesothelioma (MPM) is an aggressive tumor associated with exposure to asbestos and is rising in incidence worldwide. A lack of early detection methods and treatment successes have maintained a dismal prognosis of just 12 - 16 months. Circulating tumor DNA (ctDNA) is emerging as an important stratification biomarker in other thoracic malignancies, however research in this area has been lacking in MPM. Homozygous deletion of CDKN2A is one of the few established negatively prognostic molecular markers in MPM.

Methods and Results:

We conducted multiregional whole exome sequencing (m-WES) on tumor tissue (4 or 5 regions) and matched germline DNA from 11 patients with MPM that received surgery (extended pleurectomy decortication) as their primary treatment modality. Using a validated bioinformatics pipeline (developed as part of the TRACERx study), clonal single nucleotide variants (SNVs) and/or indels (present within all tumor regions) were selected from m-WES data for patient-specific assay design. Variants were prioritized for selection based on tumor driver status and higher mean variant allele frequencies (VAFs) amongst tumor regions. A minimum of 10 ng cfDNA isolated from pre-surgical blood was analyzed for ctDNA detection using Droplet Digital PCR (ddPCR), with positivity being defined as ≥ 3 mutant droplets and a plasma VAF ≥ 0.1%. Four out of eleven (36.4%) patients were ctDNA-positive using this patient-specific approach with VAFs ranging between 0.16% and 2.96%. Two additional patients had one or two positive mutant droplets, but these were excluded as potential false positives. In this pilot study, ctDNA-positive patients had significantly shorter survival than ctDNA-negative patients (P = 0.047), although this failed to reach significance by Cox regression analysis, likely due to a small sample size. Furthermore, in this cohort ctDNA status was a stronger prognostic biomarker than CDKN2A deletion status.

Conclusions:

Considering the short survival of patients with MPM despite surgery, we consider ctDNA-based analyses could be used to stratify patients regarding surgery, where risk-benefit would be marginal for those ctDNA-positive. This study provides proof-of-principle that the detection of tumor DNA from minimally invasive sources is possible in MPM and has alluded to how this could potentially impact clinical decision-making.

Citation Format: Luke J. Martinson, Annabel J. Sharkey, Alan G. Dawson, Robert K. Hastings, Gareth Wilson, David Waller, Apostolos Nakas, Charles Swanton, Jacqui A. Shaw, Dean A. Fennell. Personalized circulating tumor DNA profiling in malignant pleural mesothelioma [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 1349.
Abstract 1358: Tumor-derived extracellular vesicles as kidney cancer biomarkers
Authors: Zieren Richard C. , Dong Liang , Amend Sarah R. , Pierorazio Philip M. , Reijke Theo M. de , Pienta Kenneth J.
Published: August 2019

Renal cell carcinoma (RCC) is a fairly common and lethal cancer. The wide variety of RCC histological subtypes constitutes a challenge in treatment decision-making. Exosomes are extracellular membrane vesicles that are produced by all cell types in physiological conditions. Extracellular vesicles (EVs) are now accepted as a mode of intercellular communication and transport proteins, RNAs, DNA, and lipids to surrounding and distant cells. The lipid bilayer membrane of the EVs helps to protect these cargos. EVs are involved in many pathological processes, such as cancer, and can be easily obtained through liquid biopsy. Currently, EVs are rarely considered as candidate biomarkers for kidney cancer. However, improvements in the characterization of tumor-derived EVs could lead to the implementation of blood- and urine-derived EVs as biomarkers in the management of oncologic patients. Since all organs, not just the tumor, contribute to EV population, the thoughtful discrimination of tumor-derived EVs remains an unmet need for the clinical application of this kind of liquid biopsy technology. To determine the contribution of the tumor to blood- and urine-derived EVs, we utilize a novel approach to isolate tissue-derived EVs in parallel with liquid biopsy-derived EVs. To our knowledge, only a handful of studies (only one in RCC) have studied EVs directly derived from tissue. We propose the use tissue-derived EVs to screen for candidate EV biomarkers in plasma and/or urine. We hypothesize that using tissue-derived EVs would increase the tumor specificity for the characterization of EVs as liquid biopsy biomarkers. We optimized a protocol in which we used tissue of RCC patients (normal kidney or tumor) to condition media and isolate tumor-derived EVs alone by ultracentrifugation. Additionally, we isolated plasma- and urine EVs by ultracentrifugation using standard protocols. Nanoparticle Tracking Analysis (NTA) showed normalized concentrations of >2 x 109 particles/mL with a size distribution in the small EV-range. Transmission Electron Microscopy (TEM) images showed typical exosome morphology, with the characteristic cup-shaped membrane vesicles. Western Blot (WB) confirmed the presence of exosome markers. We successfully isolated EVs from human RCC and healthy kidney tissue. We will proceed with screening the EV-samples for candidate miRNA-biomarkers by multiplexed gene expression analysis, followed by confirmation of the candidate markers by RT-qPCR.

Citation Format: Richard C. Zieren, Liang Dong, Sarah R. Amend, Philip M. Pierorazio, Theo M. de Reijke, Kenneth J. Pienta. Tumor-derived extracellular vesicles as kidney cancer biomarkers [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 1358.
Abstract 1363: Identifying blood exosomal miRNAs as biomarkers in the diagnosis and prognosis of pancreatic ductal adenocarcinoma
Authors: Guo Shiwei , Wang Huan , Qin Hao , Zhang Dadong , Shao Zhuo , Zhang Yanan , Song Bin , Xu Xiaoya , Shen Jing , Chen Zishuo , Shi Xiaohan , Gao Suizhi , Pan Yaqi , Li Fugen , Jin Gang
Published: August 2019

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is of high mortality with a shortage of effective non-invasive biomarkers in the diagnosis and prognosis. Without a proper method to identify reasonable target molecules and their references for normalization, robust and accurate blood miRNA biomarkers have not been reported. We aim to explore the exosomal miRNAs as biomarkers for the diagnosis and prognosis of PDAC with sufficient biological insights and robustness.

Materials and Methods: miRNA-seq was performed on miRNAs extracted from blood exosomes. 16 non-metastatic PDAC, 11 metastatic PDAC and 15 pancreatitis patients were enrolled in 2017 as the training set. Another 18 non-metastatic PDAC, 12 metastatic PDAC and 18 pancreatitis patients were enrolled in 2018 as the testing set. Bayesian network was built on the levels of miRNAs to identify candidate biomarkers with biological insights. The area under the curve (AUC) of receiver operating characteristic (ROC) was used to measure the accuracy of each pair of miRNAs.

Results: The exosomal miRNA from the plasma of these patients with PDAC or pancreatitis has been successfully extracted and sequenced. The Bayesian network consisted of 337 nodes and 713 edges. The quotient of miR-95-3p (a “consequence” of “cancer”) over miR-26-5p (a “cause” of “pancreatitis”) performed 81.5% sensitivity and 93.3% specificity in the training cohort, and 86.7% sensitivity and 100% specificity in the testing cohort respectively. Furthermore, considering either high serum level of CA19-9 or the quotient of miR-95-3p/miR-26-5p as PDAC, the sensitivity increased to 96.5%, and the specificity was maintained at 96.9%. In addition, miR-335-5p level in blood exosome could predict metastasis with a mean accuracy of 77.2%, and showed strong relation with overall survival after surgeries.

Conclusions: MiRNAs biomarkers from blood exosomes in differential diagnostics and prognosis are identified and rationale by Bayesian network. Integration of biomarkers of various molecular types could enhance the diagnostic accuracy beyond single molecular types. Blood exosomal miRNAs could be applied to monitor the development of PDAC.

Citation Format: Shiwei Guo, Huan Wang, Hao Qin, Dadong Zhang, Zhuo Shao, Yanan Zhang, Bin Song, Xiaoya Xu, Jing Shen, Zishuo Chen, Xiaohan Shi, Suizhi Gao, Yaqi Pan, Fugen Li, Gang Jin. Identifying blood exosomal miRNAs as biomarkers in the diagnosis and prognosis of pancreatic ductal adenocarcinoma [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 1363.
Abstract 1407: Histone marks interplay at LIFR enhancer determines the response to HDAC inhibitors in breast cancer
Authors: Wang Xiaomin , Xu Jun , Ding Jian , Geng Meiyu , Huang Min
Published: August 2019

The dynamic crosstalk of epigenetic modifications is believed to impose a strong impact on epigenetically-targeted therapies, such as histone deacetylase (HDAC) inhibitors, but current understanding in this regard is extremely limited.Our previous work has revealed that the transcriptional feedback activation of leukemia inhibitory factor receptor (LIFR) limits the response to HDAC inhibitors in breast cancer. However, LIFR transcriptional response appears highly heterogeneous in breast cancer and the reason behind is unclear. This study takes LIFR as a representative to dissect how histone marks interplay determines the transcriptional outcome of epigenetically-targeted therapies. We herein discover that the H3K27 methylation specifically at LIFR enhancer restricts the H3K27 acetylation upon HDAC inhibition and prevents the upregulation of LIFR. The intrinsic level of H3K27 methylation at LIFR enhancer stratifies the responsive subset to HDAC-targeted therapies in a panel of patient-derived breast cancer models. This study provides strong evidence showing how existing histone marks and their specific localization together determine the transcriptional output and the outcome of epigenetically-targeted therapies, highlighting the significance of histone marks crosstalk in epigenetic therapeutics.

Note: This abstract was not presented at the meeting.

Citation Format: Xiaomin Wang, Jun Xu, Jian Ding, Meiyu Geng, Min Huang. Histone marks interplay at LIFR enhancer determines the response to HDAC inhibitors in 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 1407.