bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB050: Modulation of innate and adaptive immunity in blood and tumor of patients receiving the SHP2 inhibitor RMC-4630
Authors: Chen Ariel Yung-Chia , Haura Eric , Pacheco Jose , Koczywas Marianna , Gordon Michael , Ulahannan Susanna , Burris Howard A. , Ou Sai-Hong Ignatius , Wang Judy S. , Riess Jonathan W. , McCoach Caroline , Capasso Anna , Quintana Elsa , Hayes Josie , Dua Richa , Bitman Bojena , Guerra Martha , Wang Hongfang , Wang Xiaolin , Janne Pasi A.
Published: July 2021

RMC-4630 is a potent, selective, orally bioavailable allosteric inhibitor of SHP2, a central node in the RAS signaling pathway. In preclinical models, SHP2 inhibition not only directly inhibited tumor growth through suppression of tumor-intrinsic RAS signaling, but also resulted in transformation of the tumor immune microenvironment, characterized by an increase in CD8+T cell infiltrates and selective depletion of pro-tumorigenic M2 macrophages.

In this study, we evaluated pharmacodynamic biomarkers in blood and tumors from patients in the RMC-4630 phase I monotherapy clinical trial (NCT 03634982) by using flow cytometry and immunohistochemistry (IHC). Safety, PK and efficacy data are reported in a separate abstract.

Longitudinal analysis of immune cell phenotyping in blood was conducted in 35 patients. There was a trend for lower pre-study monocytic myeloid-derived suppressor cell (mMDSC) to be associated with a better clinical outcome on RMC-4630 therapy. While the proportion of circulating T cell and B cell populations did not change, both blood mMDSC and total monocytes were significantly reduced during RMC-4630 administration. Furthermore, tumor volumes changes, and the proportion of patients with SD versus PD, positively correlated with the ratio of mMDSCs to total monocytes on RMC-4630 treatment.

Inhibition of pERK was observed in a subset of patients. Three paired tumor biopsies from efficacy-evaluable patients, including 1 PR, 1 SD and 1 PD, were available for tumor microenvironment analysis by multiplexed-IHC assays. Increase in tumor infiltrating T cells in the tumors of one patient with a PR and another with SD was observed on RMC-4630 therapy. Inhibition of tumor PD-L1 expression and a decrease in M2 macrophages was also observed on treatment in the tumor biopsy of the PR patient.

Collectively, the preliminary clinical biomarker data supports the preclinical observations that SHP2 inhibition with RMC-4630 modulates both innate and adaptive anti-tumor immunity.

Citation Format: Ariel Yung-Chia Chen, Eric Haura, Jose Pacheco, Marianna Koczywas, Michael Gordon, Susanna Ulahannan, Howard A. Burris, Sai-Hong Ignatius Ou, Judy S. Wang, Jonathan W. Riess, Caroline McCoach, Anna Capasso, Elsa Quintana, Josie Hayes, Richa Dua, Bojena Bitman, Martha Guerra, Hongfang Wang, Xiaolin Wang, Pasi A. Janne. Modulation of innate and adaptive immunity in blood and tumor of patients receiving the SHP2 inhibitor RMC-4630 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB050.
Abstract LB060: Circulating tumor cells in desmoid tumors
Authors: Braun Alexcia Camila , Campos Fernando , Abdallah Emne Ali , Ruano Anna Paula , Tariki Milena , Pinto Fabio , de Mello Celso Abdon , Martins Vilma Regina , Chinen Ludmilla Thome
Published: July 2021

Introduction: Desmoid tumor (DT) is a rare neoplasm with high local recurrence rates. CTNNB1 mutations are found in most sporadic cases and are located in exon 3, usually in codons 41 or 45 (p.T41A, p.S45F and p.S45P). Circulating tumor cells (CTCs) isolated from the peripheral blood of patients with sarcomas and other neoplasms can be early biomarkers of tumor invasion and dissemination. Moreover, CTCs can also re-colonize their tumors of origin through a process of “tumor self-seeding.” Objectives: To identify CTCs in the peripheral blood of patients with DT; to evaluate their expressions of β- catenin and vimentin proteins. Materials and methods: We conducted a prospective study of patients with initially diagnosed and relapsed DT with measurable disease. Blood samples from each patient were processed and filtered by ISET® (Rarecells, France) for the isolation and quantification of CTCs. The expressions of β -catenin and vimentin in CTCs were analyzed by immunocytochemistry (ICC). Results: A total of 18 patients were included, and all had detectable CTCs. We found a concordance of β-catenin expression in CTCs and in primary tumors in 42.85% of cases by using ICC and immunohistochemistry respectively. Conclusions: Our study identified a high prevalence of CTCs in DT patients. Concordance of β-catenin expression between primary tumor and CTCs bring new perspectives to assess the dynamics of CTCs in the blood microenvironment, opening new avenues for studying the biology and behavior of DT. In addition, these results open the possibility of using CTCs to predict DT dynamics at the time of progression and during treatment. Further studies with larger sample sizes are needed to validate our findings.

Citation Format: Alexcia Camila Braun, Fernando Campos, Emne Ali Abdallah, Anna Paula Ruano, Milena Tariki, Fabio Pinto, Celso Abdon de Mello, Vilma Regina Martins, Ludmilla Thome Chinen. Circulating tumor cells in desmoid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB060.
Abstract LB065: Prostate cancer molecular immunophenotypes in biopsies with high vs average radiation sensitivity as predicted by post-operative radiation therapy outcomes (PORTOS) scores
Authors: Gaston Sandra M. , Punnen Sanoj , Kryvenko Oleksandr , Pollack Alan , Davicioni Elai , Liu Seagle , Stoyanova Radka
Published: July 2021

Background: The combination of radiation therapy and immunotherapy has emerged as an exciting field of research with the potential for significant clinical benefit. Using pre-treatment prostate biopsies from two clinical trials we explored the hypothesis that a validated gene expression signature of postoperative radiation therapy outcome score (PORTOS) is associated with differences in tumor molecular immunophenotype. In this study, we compared prostate tumors with high vs average PORTOS scores for expression of 32 molecular immunophenoscores that reflect cancer antigen profiles and the cellular composition of tumor infiltrating lymphocytes. Methods: Gene expression profiles were obtained from microdissected tumor tissue from 242 treatment naïve-prostate biopsy cores obtained from 92 patients enrolled in the University of Miami MAST (NCT02242773) and BLaStM (NCT02307058) clinical trials. For each biopsy the PORTOS score (PMID: 27743920) and 32 tumor molecular immunophenoscores (PMID: 28052254) were determined from Affymetrix Human Exon 1.0 ST microarray data using published methods. Results: 14% of the biopsy cores were predicted by the PORTOS signature to be more responsive to radiation therapy. Compared to the cores with average PORTOS scores, the “high PORTOS” biopsies showed a 2 fold or greater level of the tumor immunoactivation markers Act CD4, Act CD8, EC, HLA DPA1 and Tem CD8 and a 2 fold or lower level of the tumor immunosuppression markers MDSC, SC, TIM3 and T reg (Mann-Whitney P value of <0.0001 for all nine comparisons of medians). Discussion: Preliminary studies suggest that prostate cancers with PORTOS scores that predict greater sensitivity to radiation therapy also have immunophenotype profiles consistent with a higher level of overall immunogenicity.

Citation Format: Sandra M. Gaston, Sanoj Punnen, Oleksandr Kryvenko, Alan Pollack, Elai Davicioni, Seagle Liu, Radka Stoyanova. Prostate cancer molecular immunophenotypes in biopsies with high vs average radiation sensitivity as predicted by post-operative radiation therapy outcomes (PORTOS) scores [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB065.
Abstract LB082: Prostate cancer incidence and mortality in the United States, 2000-2016
Authors: Koko Michael Rutalira , Aranmolate Rasaki , Shah Raza Z. , Mutamba Glodi
Published: July 2021

Background/Purpose

Prostate cancer (PC) is the second most common and deadly cancer among men in the United States. In general, incidence rate of prostate cancer has declined while mortality rate has increased over the past 15 years. The purpose of this study is to assess the incidence and mortality rates of this cancer according to race/ethnicity from 2000-2016.

Methods

We obtained data from the Surveillance, Epidemiology and End Results (SEER) 18 program to calculate incidence and mortality rates by race/ethnicity from 2000 to 2016. The Annual Percent Change (APC) was also obtained for incidence and mortality rates by race/ethnicity.

Results

From 2000-2016, the overall incidence rate has decreased significantly from 77.4 to 49.1 per 100,000 (APC = -3.1). Asian and Pacific Islander had the highest decline in incidence rate from 44.4 to 23.4 per 100,000 whereas African-American had the lowest decline from 113.3 to 72.4 per 100,000 (APC -4.4 vs -2.9 respectively). Conversely, the death rate has increased substantially, particularly among White and Black (APC = 8.6 vs 6.6). However, African-Americans still have a disproportionate mortality rate compared to White (46.5 vs 28.8 per 100,000).

Conclusion

African-Americans are still suffering disproportionately from the PC. There is a need to implement public health interventions to improve PC screening among African-Americans, and examine additional factors that may contribute to the burden of this cancer among African-Americans.

Citation Format: Michael Rutalira Koko, Rasaki Aranmolate, Raza Z. Shah, Glodi Mutamba. Prostate cancer incidence and mortality in the United States, 2000-2016 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB082.
Abstract LB086: Methylation-derived neutrophil-to-lymphocyte ratio and lung cancer risk and survival
Authors: Zhao Naisi , Ruan Mengyuan , Koestler Devin , Lu Jiayun , Marsit Carmen , Kelsey Karl , Platz Elizabeth , Michaud Dominique S.
Published: July 2021

The neutrophil-to-lymphocyte ratio (NLR) is a biomarker of systemic inflammation and can be estimated using DNA methylation data as methylation-derived NLR (mdNLR). We examined associations between mdNLR and lung cancer risk in a nested case-control study, and among the cases, lung cancer survival, using pre-diagnostic blood samples of cases (median of 14 years before diagnosis) and controls in the CLUE I/II cohorts. The final analytic dataset included 208 pairs of lung cancer cases and controls matched on age, sex, and smoking intensity. We computed the mdNLR for each sample based on immune cell-proportion estimates obtained using established reference-based deconvolution methods. Using conditional logistic regression (to take into account matching factors), and further adjusting for BMI, batch effects, and a smoking-based methylation score, we observed a 47% increased risk of non-small cell lung cancer (NSCLC) for one standard deviation increase in mdNLR (n = 150 pairs; OR: 1.47 [1.08, 2.02]). To estimate association between mdNLR and lung cancer survival, we used Cox proportional-hazards models, adjusting age, sex, smoking status, smoking methylation score, BMI, batch effect, and stage. We observed a 27% increased risk of dying from lung cancer for one standard deviation increase in mdNLR (n = 145 deaths in 205 cases; HR: 1.27 [1.08, 1.50]). A 50% increased risk of dying from lung cancer for one standard deviation increase in mdNLR was observed for NSCLC cases (n = 103 deaths in 149 cases; HR: 1.50 [1.19, 1.89]). A better understanding of inflammation-associated biomarkers in lung cancer development could provide insight into critical pathways that may help identify new markers of early disease and survival.

Citation Format: Naisi Zhao, Mengyuan Ruan, Devin Koestler, Jiayun Lu, Carmen Marsit, Karl Kelsey, Elizabeth Platz, Dominique S. Michaud. Methylation-derived neutrophil-to-lymphocyte ratio and lung cancer risk and survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB086.
Abstract LB098: Vulnerability of MTAP-deleted nasopharyngeal carcinoma to MAT2A inhibition
Authors: Chan Yuk Yu , Bruce Jeff P. , Lui Vivian W.Y. , Chung Grace T. Y. , Tsao Sai-Wah , To Ka-Fai , Pugh Trevor J. , Lo Kwok-Wai
Published: July 2021

Nasopharyngeal carcinoma (NPC) is an EBV-associated cancer prevalent in Southern China and Southeast Asia. We have generated a comprehensive genomic profile of NPC using whole-genome sequencing (WGS) and established a catalogue of somatic alterations of this EBV-associated cancer. In addition to the significantly mutated genes reported in previous WES studies, our WGS study revealed recurrent structural variants (SVs) and copy number variants (CNVs) driving key oncogenic pathways, including cell cycle, NF-kappaB and TGF-beta signaling. While immediately druggable gene aberrations (e.g. PIK3CA mutations and FGFR3-TACC3 fusions) are found in only ~3-5% of NPC, a synthetic lethality-based target, homozygous deletion of MTAP defined by fine-mapping of CDKN2A/CDKN2B deletion breakpoints at chromosome 9p21.3 was frequently detected (34%). Notably, the study has also revealed mutual exclusivity among tumors with MTAP deletion and TP53 alterations (p=0.022). Loss of MTAP has further been validated in a cohort of advanced and recurrent tumors (16/50, 32%) by FISH analysis and immunohistochemistry staining. The high prevalence and clonal nature of MTAP deletion in NPC implicate synthetic lethal targeting of MTAP-deleted tumors as a potential precision treatment for NPC patients. Using a CRISPR-based MTAP-knockout cell line and MTAP-deleted patient derived xenograft (PDX), we revealed that MAT2A and PRMT5 inhibition selectively suppressed growth of MTAP-deleted NPC. Treatment with MAT2A inhibitor, FIADS-5, led to depleted PRMT5 activity and reduced symmetric arginine methylation (SAMe) in these in vitro and in vivo NPC models. In addition to selective growth inhibition, MAT2A inhibition also targeted various unique oncogenic properties in NPC. The FIADS-5 treatment was shown to induce TP53 and BAX expression, cellular differentiation and keratinization in these MTAP-deleted NPC. Our findings demonstrated the translational potential of targeting MTAP-deletion in this EBV-associated epithelial cancer.

Citation Format: Yuk Yu Chan, Jeff P. Bruce, Vivian W.Y. Lui, Grace T. Y. Chung, Sai-Wah Tsao, Ka-Fai To, Trevor J. Pugh, Kwok-Wai Lo. Vulnerability of MTAP-deleted nasopharyngeal carcinoma to MAT2A inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB098.
Abstract LB106: The EGF domains of MUC4 oncomucin interact with ErbB2 and mediate tumorigenic activity of cancer cells represent new potential therapeutic targets
Authors: STOUP Nicolas , LIBERELLE Maxime , SCHULZ Céline , VASSEUR Romain , MAGNEZ Romain , THURU Xavier , MELNYK Patricia , RENAULT Nicolas , JONCKHEERE Nicolas , LEBEGUE Nicolas , VAN SEUNINGEN Isabelle
Published: July 2021

The MUC4 mucin and its membrane partner ErbB2 form an oncogenic complex at the surface of epithelial cancer cells that promotes tumor progression. They directly physically interact via an extracellular region of MUC4 encompassing three EGF domains opening the route to therapeutic targeting of ErbB2 over-expressing cancers in which MUC4-ErbB2 is present. However, before small inhibitory molecules may be designed, it is mandatory (i) to decipher at the molecular level which amino acid regions are involved in the interaction and (ii) show that they mediate cancer cell tumorigenicity. By using in vitro (2D cell culture, Micro Scale Thermophoresis, PLA assay, Co-IP, GST pull down, Molecular Dynamics simulations) and in vivo (xenograft model of pancreatic cancer) approaches, we show that the EGF1 domain of MUC4 is central both in the interaction with ErbB2 and in the activation of cell proliferation and migration and tumor growth via activation of key oncogenic pathways (Src, Ras, p70S6K/AKT/mTOR, β-catenin, FAK). Finally, we have identified hotspots of interaction paving the way to the design of therapeutic inhibitory molecules targeting the EGF domains of MUC4 which may represent a new alternative strategy to overcome ErbB2 therapeutic failure in cancer.

Citation Format: Nicolas STOUP, Maxime LIBERELLE, Céline SCHULZ, Romain VASSEUR, Romain MAGNEZ, Xavier THURU, Patricia MELNYK, Nicolas RENAULT, Nicolas JONCKHEERE, Nicolas LEBEGUE, Isabelle VAN SEUNINGEN. The EGF domains of MUC4 oncomucin interact with ErbB2 and mediate tumorigenic activity of cancer cells represent new potential therapeutic targets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB106.
Abstract LB113: Regulation of PARP-1 expression in mammary tumor cell lines after treatment with olaparib
Authors: Moschetta-Pinheiro Marina Gobbe , Colombo Jucimara , de Souza Tuckumantel Murilo , Rebolho Gabriela Karam , Zuccari Debora Aparecida
Published: July 2021

Introduction: Breast cancer is the most common tumor type among women and has a high mortality rate, which is associated with late detection of the disease and treatment failure due to the acquisition of resistance to protocol treatments. It is known that a variety of antitumor drugs are capable of inducing chemoresistance by activating DNA repair pathways. Among these, the PARPs are involved in the recognition and repair of simple-strand breaks. As a consequence, new drugs such as PARP inhibitors (olaparib), are being investigated as potential therapeutic targets in cancer, as an alternative to evade the resistance of tumor cells to chemotherapeutic agents, such as those in the class of platinum salts. In this context, the aim of this study was to evaluate the PARP expression after olaparib tratament with in mammary tumor cell lines. Materials and Methods: Mammary tumor cell lines MDA-MB-468 and CF41 was cultured in DMEM high glucose culture medium, at 37°C in 5% CO2. Cell viability was measured by MTT assay after treatment with different concentrations of carboplatin. Once stablished the concentration of 10µM for carboplatin and 10µM of olaparib, the protein and gene expression of PARP-1 were detected by immunofluorescence and real time PCR, respectively. Results: There was a significantly decrease of cell viability after treatment with different concentrations of carboplatin in 24 hours. Both PARP-1 protein and gene expression significantly decreased after treatment with carboplatin and olaparib. In some cases, the treatment action was potentiated when performed in combination. Conclusion: Our results suggest the efficacy of olaparib in controlling the mechanism of DNA repair activated by PARPs in human and canine breast cancer cells.

Citation Format: Marina Gobbe Moschetta-Pinheiro, Jucimara Colombo, Murilo de Souza Tuckumantel, Gabriela Karam Rebolho, Debora Aparecida Zuccari. Regulation of PARP-1 expression in mammary tumor cell lines after treatment with olaparib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB113.
Abstract LB133: Targetting IL-6/gp130 signalling axis attenuates acquired drug resistance in medulloblastoma
Authors: Sreenivasan Lakshana , Leclair Pascal , Lim Chinten James
Published: July 2021

Medulloblastoma (MB) is the most common pediatric brain tumour comprising of four distinct molecular subgroups exhibiting high level of intertumoural heterogeneity. The standard multimodal treatment yields a survival rate of 70% but the aggressive treatment affects the long-term sequelae of MB patients. The tumour microenvironment (TME) is a regulator of cancer progression and affects therapeutic efficacy in primary and metastatic brain malignancies. Mechanistic insights into the tumor-promoting role of the individual components of the brain TME will aid in identifying key survival pathways and design of potential therapeutics to combat drug resistance and pathogenesis of the disease. We hypothesize that tumor associated macrophages (TAMs) in the brain TME facilitate drug resistance via the IL-6/STAT3 signalling axis in MB. To understand the role of paracrine signaling resulting from TAMs, a co-culture system was used to evaluate the expression of pSTAT3 and correlated with drug sensitivity and/or resistance in Med8A cell line. When co-cultured with HMC3, a human microglia cell line, the chemosensitive Med8A-S cells exhibited enhanced pSTAT3 expression and acquired drug resistance. Interestingly, Med8A cells lacking expression of IL-6 receptor (IL6R-/-) also exhibited high pSTAT3 levels and drug resistance; suggesting that HMC3 may release soluble factors in addition to IL-6 sufficient to drive chemoresistance in Med8A variants. To assess this, we conditioned cells with stimulatory cytokines belonging to the IL-6 family. We found that oncostatin M (OSM), interleukin-11 (IL-11) and leukemia inhibitory factor (LIF) induced drug resistance and enhanced pSTAT3 levels in IL6R-/- cells. Receptors of the IL-6 family share a common signal transducing beta subunit, glycoprotein (gp130) that transduces the signal intracellularly and phosphorylates janus activated kinases (JAKs) and subsequently STAT3. Our results suggest that paracrine proinflammatory cytokines found in the TME can promote MB drug resistance by signalling through a common signal transducer gp130, hence targeting any one cytokine receptor of the IL-6 family of cytokines may not sufficiently abrogate acquired drug resistance. Currently, we are evaluating the efficacy of agents that target common downstream elements of the IL-6/STAT3 signalling axis, including gp130, JAKs and STAT3, as a potentially improved therapeutic strategy to circumvent acquired drug resistance in medulloblastoma.

Citation Format: Lakshana Sreenivasan, Pascal Leclair, Chinten James Lim. Targetting IL-6/gp130 signalling axis attenuates acquired drug resistance in medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB133.
Abstract LB143: BNZ-2, a dual specific IL15/IL21 inhibitor, rescues humanized NOG-IL15 transgenic mice from intestinal acute graft versus host disease without disrupting NK and CD8 T cell engraftment
Authors: Kipp Kevin R. , Doerr Nick , Al-Mawsawi Laith Q. , Kim Woo Jae , Giovannone Adrian J. , Azimi Nazli
Published: July 2021

Advances in adoptive transfer immunotherapy have found beneficial effects for Interleukin-15 (IL-15) in the graft versus tumor (GvT) activity of NK and cytotoxic T cells. However, the benefits of this activity must be weighed against the increased risk of acute graft versus host disease (GvHD) in patients. We propose that BNZ-2, a peptide antagonist of IL-15 and IL-21 signaling, as a therapeutic option for GvHD that may relieve intestinal pathologies while retaining adoptive transfer activity. As a novel model of intestinal inflammatory disease, we have found that humanization with peripheral blood mononuclear cells (PBMCs) of NOG mice with transgenic expression of human IL-15 (NOG-IL15) consistently catalyzes the onset of intestinal GvHD within twenty days of engraftment. To investigate whether BNZ-2 can inhibit IL-15-catalized intestinal GvHD we treated NOG-IL15 mice and assessed the degree of intestinal GvHD and the immunophenotype of engrafted cells following twenty days of humanization with four million unmanipulated PBMCs. BNZ-2 treatment inhibited with equal efficacy to anti-IL-15 the localization of immune cells to the intestinal lamina propria protecting the tissue from inflammation-induced loss of tissue integrity. However, BNZ-2 treatment retained the systemic engraftment of the blood and spleen, including NK and CD8 cytotoxic T-cells. These data support BNZ-2 as a therapeutic candidate for GvHD treatment, describe a new model of intestinal GvHD, and suggest that a therapeutic window exists that separates intestinal GvHD pathologies from the benefits of adoptive cell transfer.

Citation Format: Kevin R. Kipp, Nick Doerr, Laith Q. Al-Mawsawi, Woo Jae Kim, Adrian J. Giovannone, Nazli Azimi. BNZ-2, a dual specific IL15/IL21 inhibitor, rescues humanized NOG-IL15 transgenic mice from intestinal acute graft versus host disease without disrupting NK and CD8 T cell engraftment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB143.
Abstract LB169: Systemic Administration of an antibody/RNA complex results in tumor specific delivery of immunostimulatory RNAs and tumor growth suppression in a mouse model of melanoma
Authors: Quijano Elias , Liu Yanfeng , Squinto Stephen , Turner Bruce C. , Glazer Peter M.
Published: July 2021

There is intense interest in the development of nucleic acid ligands for immune stimulation of the tumor microenvironment via pattern recognition receptors, especially for the treatment of “cold” tumors. However, delivery of these ligands in a tumor-specific manner to avoid systemic toxicity has been a challenge. Many current efforts rely on direct intra-tumoral injection of RNAs or other stimulatory immune ligands, which is therapeutically sub-optimal, especially for metastatic disease. Here we report studies evaluating the utility of a lupus-derived, cell-penetrating antibody, to deliver nucleic acids including mRNA to tumors in vivo. This antibody, a modified version of 3E10-D31N, forms non-covalent complexes with RNAs and can mediate highly specific delivery broadly into tumors via intravenous injection by targeting the nucleoside transporter ENT2. Studies with labeled RNAs and with mRNAs expressing a GFP reporter gene show tumor specific delivery and functional expression by imaging, with minimal delivery to healthy tissues. Cell culture studies show antibody-mediated delivery of a series of RIG-I ligands, including hairpin RNAs and poly(I:C), resulting in robust RIG-I stimulation and induction of type-1 interferon signaling. Using mouse B16 melanoma tumors as a model, we observe substantial tumor growth suppression upon i.v. injection of a combination of 3E10 complexed with poly(I:C) (synthetic double-stranded RNA). These results highlight a novel approach for the systemic delivery of immunostimulatory RNAs in a targeted manner that may offer treatment advantages over current approaches.

Citation Format: Elias Quijano, Yanfeng Liu, Stephen Squinto, Bruce C. Turner, Peter M. Glazer. Systemic Administration of an antibody/RNA complex results in tumor specific delivery of immunostimulatory RNAs and tumor growth suppression in a mouse model of melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB169.
Abstract LB185: BBX and PLK1 feedback mechanisms regulate mitotic entry & exit
Authors: Li Gaiyun , Gillison Maura L.
Published: July 2021

Bobby Sox Homolog (BBX) is a highly conserved member of the high mobility group (HMG) box family of transcription factors, but its function remains largely unknown. We find human papillomavirus positive oropharyngeal squamous cell carcinomas (HPV-OPSCC) are enriched for BBX amplification and single nucleotide variants clustered within the BBX lysine rich domain. We therefore used the immortalized keratinocyte cell line HaCaT to elucidate BBX function. BBX is localized primarily in the nucleus. Cell synchronization at G1-S or G2-M shows BBX mRNA transcription and protein expression are highest at G1-S and rapidly decline at G2-M. Immunofluorescence (IF) shows high nuclear BBX expression during interphase and rapid reduction at mitosis (M). Induced overexpression of BBX decreases cellular proliferation, prolongs M phase, induces senescence, increases frequency of binucleated cells, and increases DNA damage as measured by γH2AX. Knockdown of BBX expression decreases cell proliferation, shortens M phase, and results in several mitotic defects, including lagging chromosomes, micronuclei, multi-polar spindles, and binucleated cells. Because effects of BBX dysregulation mirror those of Polo-like kinase-1 (PLK1), we investigated possible BBX-PLK1 interactions. BBX induction increases, whereas knockdown decreases, PLK1 mRNA and protein expression. BBX strongly activated transcription of the PLK1 promoter in a luciferase reporter assay. In contrast, PLK1 dramatically decreased BBX protein, but not mRNA, expression, and this effect was attenuated by a PLK1 T210 inactivating mutation and by a PLK1 small molecule inhibitor. We found a strong positive correlation between BBX and PLK1 mRNA expression in HNSCC tumors, but not in normal tissues. We conclude that BBX and PLK1 interact in a feedback mechanism to precisely regulate the G2-M transition. Future work will investigate interactions between BBX, HPV oncoproteins, and regulation of the cell cycle.

Citation Format: Gaiyun Li, Maura L. Gillison. BBX and PLK1 feedback mechanisms regulate mitotic entry & exit [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB185.
Abstract LB190: DNAscopeTM: A novel chromogenic in-situ hybridization technology for high-resolution detection of DNA copy number and structural variations
Authors: Wang Li-Chong , Tondnevis Farzaneh , Todorov Courtney , Gaspar Jayson , Sahajan Aparna , Murlidhar Vasudha , Zhang Bingqing , Ma Xiao-Jun
Published: July 2021

Genomic DNA anomalies such as copy number variations (gene duplication, amplification, deletion) and gene rearrangements are important biomarkers and drug targets in many cancer types. DNA in-situ hybridization (ISH) is the gold standard method to directly visualize these molecular alterations in formalin-fixed paraffin-embedded (FFPE) tumor tissues at single-cell resolution within a histological section. However, currently available fluorescent ISH (FISH) assays provide limited morphological detail due to the use of fluorescent nuclear staining compared to chromogenic staining. Furthermore, FISH techniques rely on expensive fluorescence microscopes, risk loss of fluorescent signal over time and involve tedious imaging at high magnifications (100X). There is thus an unmet need for a sensitive and robust chromogenic DNA-ISH assay that can enable high-resolution detection of genomic DNA targets with the ease of bright-field microscopy. We present here DNAscope - a novel chromogenic DNA-ISH assay - for detecting and visualizing genomic DNA targets under a standard light microscope. DNAscope is based on the widely used RNAscope® double-Z probe design and signal amplification technology and provides unparalleled sensitivity and specificity with large signal dots readily visualized at 40X magnification and with full morphological context. Furthermore, DNAscope ensures specific DNA detection without interference from RNA due to the use of a novel RNA removal method. Using a duplex chromogenic detection assay in red and blue, we demonstrate highly specific and efficient detection of gene rearrangements (ALK, ROS1, RET and NTRK1), gene amplification (ERBB2, EGFR, MET) and deletion (TP53 and CDKN2A). The DNAscope assay has been carefully optimized for probe signal size and color contrast to enable easy interpretation of signal patterns under conventional light microscopy or digital pathology. Compared to conventional FISH assays, DNAscope probes are standard oligos that are designed in silico to be free of any repetitive sequences and can be rapidly synthesized for any DNA target. In conclusion, the DNAscope assay provides a powerful and convenient alternative to commonly used FISH assays in many cancer research applications.

Citation Format: Li-Chong Wang, Farzaneh Tondnevis, Courtney Todorov, Jayson Gaspar, Aparna Sahajan, Vasudha Murlidhar, Bingqing Zhang, Xiao-Jun Ma. DNAscopeTM: A novel chromogenic in-situ hybridization technology for high-resolution detection of DNA copy number and structural variations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB190.
Abstract LB193: Lysine demethylase 5A is required for MYC driven transcription in multiple myeloma
Authors: Qi Jun , Ohguchi hiroto , Park Paul MC , wang tingjian , Anderson Kenneth C. , Hideshima Teru , Johansson Catrine , Oppermann Udo , Durbin Adam D. , Gryder Berkley , Khan Javed , zhang xiaofeng
Published: July 2021

Multiple myeloma (MM) is a malignant plasma cell disorder accounting for 10% of hematologic malignancies. Although high dose chemotherapy and targeted agents have improved patient outcomes, MM remains an incurable disorder. Thus, there is an urgent need to develop novel therapeutic strategies. We discovered that the distinct lysine demethylase 5A (KDM5A) plays a critical role in MM cell growth, through a unique link to MYC-driven transcriptional programs. KDM5A is a dominant regulator of histone H3K4 trimethylation, a histone mark associated with activated gene transcription. We identify that KDM5A interacts with P-TEFb complex and cooperates with MYC to control MYC targeted genes in MM cells. We develop a novel, cell-permeable and selective KDM5 inhibitor, JQKD82 that increases histone H3K4me3, and inhibits downstream MYC-driven transcriptional output in vitro and in vivo. Utilizing genetic ablation together with our inhibitor, we established a detail mechanism that KDM5A is required for transcriptional pause release by P-TEFb at MYC target genes. These data identify KDM5A as a unique vulnerability in MM through regulation of the driving MYC oncogene in MM, and defined JQKD82 as a tool compound to block KDM5A function as a potential therapeutic strategy for MM.

Citation Format: Jun Qi, hiroto Ohguchi, Paul MC Park, tingjian wang, Kenneth C. Anderson, Teru Hideshima, Catrine Johansson, Udo Oppermann, Adam D. Durbin, Berkley Gryder, Javed Khan, xiaofeng zhang. Lysine demethylase 5A is required for MYC driven transcription in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB193.
Abstract LB213: ACTL6A (Actin-like Protein 6A) enhances the cancer phenotype
Authors: Shrestha Suruchi , Adhikary Gautam , Xu Wen , Kandaysamy Sivaveera , Eckert Richard L.
Published: July 2021

Epidermal squamous cell carcinoma (SCC) is an extremely common, invasive and metastatic cancer. ACTL6A, an important protein subunit of the SWI/SNF epigenetic regulatory complex, is frequently overexpressed in cancer cells. In the present study, we show that ACTL6A drives SCC cell proliferation, invasion, migration and tumor formation, and that this aggressive phenotype is markedly reduced in ACTL6A knockdown cells. Expression of ACTL6A is associated with reduced p21Cip1 level and treatment with ACTL6A-siRNA results in a marked increase in p21Cip1 and attenuation of the cancer phenotype. Molecular studies reveal that ACTL6A suppresses p21Cip1 promoter activity to reduce mRNA and p21Cip1 protein and that loss of p21Cip1 expression appears to be biologically meaningful, as p21Cip1 knockdown enhances the aggressive phenotype. ACTL6A suppression of p21Cip1 expression requires the p53 and Sp1 transcription response elements in the p21Cip1 gene promoter. In addition, ACTL6A knockdown results in increased p53 tumor suppressor expression. These studies show that ACTL6A facilitates an aggressive cancer phenotype by reducing p53 and p21Cip1 mRNA and protein and suggests that ACTL6A contributes to an aggressive cancer phenotype in epidermal squamous cell carcinoma.

Citation Format: Suruchi Shrestha, Gautam Adhikary, Wen Xu, Sivaveera Kandaysamy, Richard L. Eckert. ACTL6A (Actin-like Protein 6A) enhances the cancer phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB213.
Abstract ND04: CLBR001+SWI019: A novel switchable CAR-T cell platform enabling functionally reversible on/off control of CAR-T cell activity for B cell malignancies
Authors: Young Travis
Published: July 2021

Chimeric antigen receptor (CAR) T cell therapy targeting CD19 has been transformative in the treatment of patients with relapsed, refractory B cell malignancies. However, despite remarkable response rates, CAR-T cell therapy is limited by the potential for uncontrolled cytokine production from the genetically engineered cells, resulting in cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). Further, continuous activity of CD19-targeted CAR-T cells can result in persistent B cell aplasia due to on-target, off-tumor activity of CAR-T cells.

To address these challenges, we have developed a novel “switchable” CAR-T cell therapy which affords greater versatility and the potential for improved efficacy and safety compared with existing CAR-T cell approaches. The therapy has been designed in two parts - first, a “universal” genetically engineered autologous humanized, third generation CAR-T cell (CLBR001); and second, a humanized antibody-based “switch” molecule (SWI019) with conventional drug-like properties that controls the genetically engineered cells. As designed, SWI019 controls the turning “on” and “off” of the CLBR001 CAR-T cells. We have shown, the dose of SWI019 tightly correlates with the amount of cytokine produced from CLBR001 while retaining potent in vivo activity in mouse models of leukemia. Importantly, cessation of SWI019 dosing in preclinical models led to termination of CLBR001 cytotoxic and cytokine production within 5 days. This is expected to be important in mitigating adverse events such as CRS and ICANS in patients. We further found that the cyclical nature of on/off stimulation of the switchable CAR-T cells affords greater memory and persistence of the cells in surrogate mouse models, while also allowing B cell repopulation, thus avoiding potential long-term adverse events due to B cell aplasia. A Phase 1 trial was initiated in mid-2020 for patients with relapsed, refractory B cell malignancies. We believe this approach has the potential to be applied to solid tumors in the future leveraging these “universal” CLBR001 CAR-T cells.

Citation Format: Travis Young. CLBR001+SWI019: A novel switchable CAR-T cell platform enabling functionally reversible on/off control of CAR-T cell activity for B cell malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr ND04.
Abstract ND10: Discovery of RMC-5552: A selective bi-steric inhibitor of mTORC1 that suppresses 4EBP1 phosphorylation, for the treatment of mTORC1-activated tumors including RAS pathway escape
Authors: Burnett G. Leslie
Published: July 2021

The PI3K/mTOR and RAS signaling pathways are hyperactivated in a wide range of human cancers. Several points of cross-talk and intersecting feedback mechanisms have been described and activation of mTOR signaling frequently mediates escape from RAS pathway inhibition. Revolution Medicines has developed a novel class of selective mTORC1 inhibitors, termed ‘bi-steric inhibitors', that interact with both the ATP- and FKBP12/FRB-binding sites of mTORC1. These compounds potently and selectively inhibit mTORC1 over mTORC2 and other lipid kinases. Unlike rapalogs, such as everolimus, these bi-steric inhibitors suppress 4EBP1 phosphorylation in vivo and induce growth suppression and apoptosis in various genetically-defined preclinical models of human cancer. We will describe our SAR investigations and findings for our preclinical tool compound, RMC-6272 (also known as RM-006) and for RMC-5552, our clinical candidate. We will demonstrate that mTORC1-selective bi-steric inhibitors show combinatorial activity with both KRASG12C(OFF) and KRASG12C(ON) inhibitors, in KRASG12C STK11deficient NSCLC models and can forestall resistance to KRASG12C inhibitor monotherapy. In addition, we will show single agent activity of bi-steric mTORC1 inhibitors in preclinical models of tumors bearing PI3K/mTOR pathway alterations as primary drivers, including PTEN-deficient glioblastoma multiforme, TSC1/2-deficient renal cystadenoma cancer, and hepatocellular cancers harboring mTOR-activating β-catenin mutations. RMC-5552, through reactivation of 4EBP1 and inhibition of cap-dependent translation, has the potential to benefit cancer patients with genetically-defined tumors with activating mutations in the RAS and PI3K/mTOR pathways both as a single agent or in combination with RAS inhibitors.

Citation Format: G. Leslie Burnett. Discovery of RMC-5552: A selective bi-steric inhibitor of mTORC1 that suppresses 4EBP1 phosphorylation, for the treatment of mTORC1-activated tumors including RAS pathway escape [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr ND10.
Abstract PL03-03: Inherited susceptibility to cancer: From family reunions to the front line of precision healthcare
Authors: Olopade Olufunmilayo I.
Published: July 2021

Cancer genomics has shed much light on tumorigenesis, leading to improved diagnoses and treatments. The marriage of Big Data and genetics research has produced groundbreaking, epidemiologic studies of large swaths of the world's population showing the links between cancer(s) and inherited risk. This work has led to breakthroughs in our understanding of pathogenic mutations, such as in BRCA1 and BRCA2 genes—strong predictors of breast and ovarian cancer risk and possibly the strongest known predictors of aggressive prostate cancer risk. Inherited and sporadic forms of cancer often share common mutational events, with implications for diagnosis, prognosis, treatment and prevention. Our work and that of others demonstrate the significant burden of early onset ER negative breast cancer as well as high rates of pathogenic BRCA1, BRCA2 and PALB2 mutations among young women diagnosed with breast cancer. Our more recent work on the BRCA1 pseudogene identifies a novel mechanism of innate immunity driven by a host pseudogene RNA that inhibits innate immune defense mechanisms and anti-tumor responses through regulation of antiviral gene expression. Genome-Wide Association Studies (GWAS) have also identified single nucleotide polymorphisms (SNPS) associated with increased breast cancer risk, including SNP rs13074711 identified from GWAS in women of African Ancestry with breast cancer, which regulates TNFSF10/TRAIL expression in ER negative breastcancer cells. Germline genetics influence somatic mutations and the evolutionary trajectory and life history of individual cancer genomes in diverse populations. Deeper understanding of the nature of this influence will allow us to explore innovative interventions to accelerate progress in precision health care and promote health equity.

Citation Format: Olufunmilayo I. Olopade. Inherited susceptibility to cancer: From family reunions to the front line of precision healthcare [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr PL03-03.
Abstract SY16-02: Using patient-derived models for functional precision oncology in advanced breast cancer
Authors: Welm Alana L.
Published: July 2021

Patient derived xenografts (PDX) are valuable, clinically-relevant models of cancer. Their close genomic, phenotypic, and temporal association with patient tumors makes them well-suited for pre-clinical and co-clinical studies that assess the potential of new therapeutics. However, PDX models are not amenable to large-scale drug sensitivity studies or real-time precision oncology due to their relatively slow growth, high cost, and low throughput. To address this, we established and characterized organoid lines from breast cancer patient tumors and PDXs and evaluated their fidelity to the original tumors and their utility in high-throughput therapeutic studies. Results of comparisons between in vitro and in vivo patient-derived models of breast cancer will be presented, along with extension of this technology to inform patient care in an IRB-approved study of precision oncology. Our work demonstrates that breast cancer organoid models are a powerful parallel resource to PDX models, especially useful for efficient determination of drug responses, and are amenable to informing real-time patient care in a functional precision oncology setting.

Citation Format: Alana L. Welm. Using patient-derived models for functional precision oncology in advanced breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr SY16-02.