bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5465: Discovery of LXRβ selective agonists promote immune cell activation and induce tumor growth inhibition in syngeneic tumor model
Authors: Pujala Brahmam , Sathe Balaji Dashrath , Gupta Ashu , Danodia Abhinandan , Soni Sanjeev , Kumar Vivek , Saeed Uzma , Chakravarty Sarvajit
Published: June 2022

Nuclear receptors, liver X receptor-α (LXRα) and liver X receptor-β (LXRβ), are considered master regulators of lipid homeostasis and play pivotal roles in several physiological and pathological processes ranging from energy supply, cardiovascular, immunity, neurodegenerative disorders and cancer. Therapeutic agonism of the LXR/ApoE axis has proven to promote anti-tumor immunity by targeting immunosuppressive innate immune cells.1 LXR-ApoE pathway regulate the innate immune system in cancer, via modulation of the activity and abundance of myeloid derived suppressor cells (MDSC) and DCs. ApoE binds to Lipoprotein receptor-related protein (LRP) on MDSC induces apoptosis, thus resulting in immune-mediated anti-tumor activity of LXR agonists. Development of LXR agonists as therapeutics has proven quite challenging due to their precipitation of hepatic steatosis and hypertriglyceridemia. Most of the lipogenic effects of LXR agonists are mediated through LXRα.2 LXR subtype-specific agonists (LXRβ specific), may overcome hepatic triglyceride accumulation and (transient) hypertriglyceridemia. Here we report the discovery of IBS624 which is the most selective LXR agonist till date, >185X selective for LXRβ over LXRα. IBS-624 has reasonable exposure in mouse with 40% oral bioavailability. IBS-624 was well tolerated at 100mg/kg, BID for 14 days with no increase in triglycerides and neutropenia. IBS-624 has shown efficacy in MC38 colon cancer model as single agent as well as in combination with Checkpoint inhibitor. 1. Cell. 2018, 172(4): 825-840. 2. Biochemical pharmacology 2006, 71, 453-463

Citation Format: Brahmam Pujala, Balaji Dashrath Sathe, Ashu Gupta, Abhinandan Danodia, Sanjeev Soni, Vivek Kumar, Uzma Saeed, Sarvajit Chakravarty. Discovery of LXRβ selective agonists promote immune cell activation and induce tumor growth inhibition in syngeneic tumor model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5465.
Abstract 5480: Aristolochic acid as a scaffold for antitumor drug development
Authors: Hashimoto Keiji , Chennamshetti Rajesh , Bonala Radha , Johnson Francis , Grollman Arthur P. , Sidorenko Viktoriya S.
Published: June 2022

We have synthesized an analog of aristolochic acid (AA) with potent growth inhibitory activity in various human cancer cell lines and report here on mechanistic studies of this potential therapeutic. AA is a natural product and the main active principle of Aristolochia plants, a known source of antitumor agents. In 1964 due to nephrotoxicity, drug development efforts with AA were terminated following Phase I clinical trial in patients with terminal cancer of different origin. Structure activity studies of AA species allowed us to select a structural analog of AA (RJ-34) that lacks the determinants responsible for the renal toxicity and carcinogenicity of the parent compound. Building further on our experience with AA molecules, we developed a synthetic approach that affords efficient high-yield synthesis of RJ-34. Its structure and purity has been confirmed by high-performance liquid chromatography, liquid chromatography coupled with two-stage mass spectrometry and high resolution nucleic magnetic resonance. Sulforhodamine B assay revealed that RJ-34 has growth inhibitory activity in A549 and HCT-15 human cancer cell lines comparable to or stronger than that of paclitaxel or topotecan. At five nanomolar, RJ-34 inhibited DNA synthesis and cut the growth of A549 cells by 50%, leading to cell cycle arrest in G1/M and G2/S, with apparent apoptosis at concentrations greater than 200 nanomolar. Notably, protein synthesis in cultured cells, as evaluated by puromycin labelling, remained unaffected. RJ-34 was screened against the NCI-60 cell line panel - encompassing sixty human cancer cell lines from various tissues - providing clues to its mechanisms of action; namely, that RJ-34 acts through inhibition of DNA topoisomerases I and II and/or DNA intercalation. Follow-up studies using purified calf Topo I and human Topo II alpha and various plasmid substrates confirmed the role of RJ-34 as a DNA intercalator and human Topoisomerase II alpha poison. The pattern of activity of RJ-34 in the NCI-60 panel was distinct from that of AA and aristolactam - another related compound - suggesting that RJ-34 acts by mechanisms distinct from AA. In summary, RJ-34— a non-nephrotoxic analog of aristolochic acid— has a potent growth inhibitory activity in various human cancer cell lines with a mechanism of action different from the parent AA. Moving forward, pre-clinical pharmacokinetics, safety and efficacy studies are necessary to establish the potential of RJ-34 for development as an anticancer therapeutic.

Citation Format: Keiji Hashimoto, Rajesh Chennamshetti, Radha Bonala, Francis Johnson, Arthur P. Grollman, Viktoriya S. Sidorenko. Aristolochic acid as a scaffold for antitumor drug development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5480.
Abstract 5482: Natural product inhibitor of Stat3, G6PD, and TrxR1 functions induces an early oxidative stress and pyroptosis, and a late-stage DNA damage and cell cycle arrest to block tumor growth in human breast cancer models
Authors: Zhu Yinsong , Dickinson Cody F. , Yang Justin , Datanagan Kyrstin , Zhai Ning , Yue Peibin , Lopez-Tapia Francisco , Tius Marcus A. , Turkson James
Published: June 2022

Bioactive natural products have led to new drugs or been the inspiration for developing new treatments. Signal transducer and activator of transcription (STAT)3 is a an oncogene that has been implicated in many human cancers. We report that the hirsutinolide natural product, R001, blocks STAT3 DNA-binding activty in vitro. Treatment with R001 of the human triple-negative breast cancer (TNBC) cells, MDA-MB-231 and MDA-MB-468 led to the concurrent inhibition of constitutively-active STAT3 and the expression and activities of glucose-6-phosphate 1-dehydrogenase (G6PD) and thioredoxin reductase (TrxR)1, early suppression of glutathione (GSH), and the induction of reactive oxygen species (ROS), which peaked at 6-24 h post R001-treatment. In the short term, R001-treated TNBC cells showed evidence of pyroptotic cell death. Prolonged treatment of TNBC cells with R001 led to DNA damage and G2/M-phase cell cycle arrest, which are late-stage responses that were preceded by the suppression of ATM-Chk2-Cdc25c pathway, and the induction of p21 and γH2AX phosphorylation by the natural product. Accordingly, R001 suppressed the viable cell numbers, colony formation, growth in 3D-matrigel, and the migration of MDA-MB-231 and MDA-MB-468 cells in vitro. The oral administration of R001 at 5 mg/kg signficantly inhibited growth of human MDA-MB-468 xenografts in mice. Results together show that R001 inhibits STAT3, G6PD and TrxR1 functions that lead to early oxidative stress and pyroptosis and late-stage DNA damage and cell cycle arrest, which collectively cause tumor cell death and tumor growth inhibition in human TNBC models.

Citation Format: Yinsong Zhu, Cody F. Dickinson, Justin Yang, Kyrstin Datanagan, Ning Zhai, Peibin Yue, Francisco Lopez-Tapia, Marcus A. Tius, James Turkson. Natural product inhibitor of Stat3, G6PD, and TrxR1 functions induces an early oxidative stress and pyroptosis, and a late-stage DNA damage and cell cycle arrest to block tumor growth in human breast cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5482.
Abstract 5492: Activity of RP7214, a novel, selective, and potent small molecule inhibitor of DHODH, in AML
Authors: Viswanadha Srikant , Eleswarapu Satyanarayana , Vakkalanka Swaroop
Published: June 2022

Background: Dihydroorotate dehydrogenase (DHODH), a rate limiting enzyme in pyrimidine synthesis, is overexpressed in certain cancers and impedes tumor cell proliferation via cell cycle arrest. RP7214 is a novel and potent DHODH inhibitor that inhibited DHODH activity in enzyme and PHA induced HWB/PBMC proliferation with IC50 and EC50 values of 7.8 & 2.5/0.60 nM respectively. Herein, we describe the efficacy of RP7214 as a single agent and in combination with standard of care drugs in preclinical models of AML

Methods: Cell viability of AML cell lines (U937, HL-60, THP-1, and KG-1) following incubation with RP7214 as a single agent or in combination with Azacytidine or Venetolcax for 72 h was determined in an MTT-based assay. Cell surface expression of CD11b in THP-1 and human primary bone marrow AML mononuclear cells in presence of RP7214 was evaluated by flow cytometry. Apoptosis was evaluated following incubation of cell lines with compound for 48 or 72 h, subsequent staining with Annexin-V-PE and 7-AAD, and analysis by flow cytometry. Anti-tumor potential of RP7214 as single agent was tested in subcutaneous MV-4-11 human leukemia xenograft model.

Results: RP7214 inhibited AML cell proliferation in all the four cell lines tested with GI50 ranging from 2.4 to 7.6 µM. Expression of the CD11b marker on THP-1 cell surface was enhanced by 40% following incubation with 5 µM compound; effect of which was reduced to 15% in the presence of 300 µM Uridine. Incubation of primary human bone marrow AML mononuclear cells with 10 µM of RP7214 increased the CD11b+ cells by > 15 %. Combination of 3 µM-RP7214 and 1 µM-Azacytidine inhibited cell proliferation by > 25% (P < 0.05) compared to single agents in MV-4-11 cells. Similarly, combination of 3 µM-RP7214 with 3 nM Venetoclax demonstrated 15% (P < 0.05) inhibition of cell growth compared to single agents in MV-4-11 cell line. RP7214 at 3, 10, and 30 mg/kg BID demonstrated significant anti-tumor activities in both tumor size and tumor weight in subcutaneous MV-4-11 human leukemia xenograft model.

Conclusions: Results demonstrate the utility of RP7214 as a single agent and in combination with standard of care drugs in inducing apoptosis and promoting differentiation to fully mature cells in AML. A Phase 2a trial in AML patients is planned.

Citation Format: Srikant Viswanadha, Satyanarayana Eleswarapu, Swaroop Vakkalanka. Activity of RP7214, a novel, selective, and potent small molecule inhibitor of DHODH, in AML [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5492.
Abstract 5493: Activity of RP12146, a novel, selective, and potent small molecule inhibitor of PARP 1/2, in solid tumors
Authors: Viswanadha Srikant , Eleswarapu Satyanarayana , Rasamsetti Kondababu , Polimati Haritha , Veeraraghavan Sridhar , Vakkalanka Swaroop
Published: June 2022

Introduction: The Poly (ADP-ribose) polymerase (PARP) family plays an important role in the regulation of transcription, apoptosis and DNA damage response. Several PARP inhibitors have been approved for the treatment of BRCA-mutated ovarian, breast and pancreatic cancer. Through ‘synthetic lethality’, the applicability PARP inhibitors can be expanded to cancers beyond the well-defined BRCA defects either as monotherapy or in combination with established therapy across various solid tumor types. Herein, we describe the efficacy of RP12146 as a single agent and in combination with approved therapies in preclinical models of solid tumors.

Methods: Enzymatic potency was evaluated using a PARP Chemiluminescent Activity Assay Kit (BPS biosciences). Cell growth was determined following incubation with RP12146 as a single agent or in combination with approved agents in various solid tumor cell lines. Apoptosis was evaluated following incubation of cell lines with compound for 48 or 72 h, subsequent staining with Annexin-V-PE and 7-AAD, and analysis by flow cytometry. Anti-tumor potential of RP12146 as a single agent or in combination with chemotherapeutic agents was tested in OVCAR-3 and NCI-H69 Xenografts. Expression of downstream PAR, PARP-trapping, and cleaved PARP expression were determined in cell lines and xenograft tumor samples by Western blotting. Plasma and tumor concentration of RP12146 in NCI-H69 xenograft samples were also determined.

Results: RP12146 demonstrated equipotent inhibition of PARP1 (0.6 nM) and PARP2 (0.5 nM) with several fold selectivity over the other members of the PARP family. Compound caused a dose-dependent growth inhibition of both BRCA mutant and non-mutant cancer cell lines with GI50 in the range of 0.04 µM to 9.6 µM. Combination of RP12146 with Temozolomide, Topotecan, Lurbinectedin, and Abemaciclib demonstrated either additive or synergistic effects manifested by an inhibition in growth of solid tumor cell lines. RP12146 exhibited anti-tumor potential with TGI of 28% and 21.8% as a single agent in OVCAR-3 and NCI-H69 Xenograft model respectively. In NCI-H69 xenograft model, RP12146 in combination with cisplatin exhibited TGI of 69.3 %.

Conclusion: Data demonstrate the therapeutic potential of RP12146 as single agent and in combination in solid tumors. RP12146 is currently being evaluated in Phase 1 clinical trials in patients with locally advanced or metastatic solid tumors (NCT05002868).

Citation Format: Srikant Viswanadha, Satyanarayana Eleswarapu, Kondababu Rasamsetti, Haritha Polimati, Sridhar Veeraraghavan, Swaroop Vakkalanka. Activity of RP12146, a novel, selective, and potent small molecule inhibitor of PARP 1/2, in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5493.
Abstract 5548: PB101 simultaneously targets tumor angiogenesis and immunity and enhances the efficacy of PD-L1 immune checkpoint blockade
Authors: Yang Hannah , Lee Seung Joon , Yang Hyun-Gul , Lee Won Suk , Cheon Jaekyung , Kang Beodeul , Kim Sung-Eun , Lim Hyeseong , Chon Hong Jae , Kim Chan
Published: June 2022

Introduction: Tumor vasculature plays an important role in promoting tumor progression and immune evasion. Previously, we developed PB101, a novel glycosylated decoy receptor that can neutralize VEGF-A, VEGF-B, and PlGF, and demonstrated that it potently inhibits tumor angiogenesis, thereby retarding tumor growth and metastasis. However, its impact on tumor microenvironment (TME), especially anti-cancer immunity, has not been fully elucidated. Here, we investigated distinct modes of immune modulation by PB101 compared with other anti-angiogenic agents, and evaluated its immunotherapeutic potential when combined with immune checkpoint inhibitors (ICIs).

Methods: MC38 colon or Hepa-V liver cancer-bearing mice were treated with PB101 or other anti-angiogenic agents with or without various ICIs. The TME was evaluated by histologic, flow cytometric, and Nanostring immune profiling analyses.

Results: PB101 markedly suppressed MC38 colon and Hepa-V liver cancer growth in vivo. It simultaneously inhibited both VEGF and PlGF signaling within the TME, thus suppressing tumor angiogenesis. PB101 also induced extensive immune remodeling of the TME. PB101 enhanced intratumoral dendritic cells, but reduced M2-like tumor-associated macrophages. Moreover, PB101 resulted in high influx of activated CD8+, but not CD4+, T cells into the TME. PB101 exhibited the most prominent immune-modulating effect compared with other vascular targeting agents. When combined with various ICIs, PB101 had the greatest synergism with anti-PD-L1 antibody, inducing complete tumor regression and long-term survival. Furthermore, PB101-based combination immunotherapy induced a durable and protective immunity against subcutaneous tumor re-challenge and hematogenous lung metastasis.

Conclusion: PB101 elicited strong anti-tumor immunity more effectively than other anti-angiogenic agents. PB101 can strengthen the immunotherapeutic efficacy of PD-L1 inhibitor by establishing a potent and durable immune memory. The combination of PB101 and PD-LI needs to be further validated in clinical trials.

Citation Format: Hannah Yang, Seung Joon Lee, Hyun-Gul Yang, Won Suk Lee, Jaekyung Cheon, Beodeul Kang, Sung-Eun Kim, Hyeseong Lim, Hong Jae Chon, Chan Kim. PB101 simultaneously targets tumor angiogenesis and immunity and enhances the efficacy of PD-L1 immune checkpoint blockade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5548.
Abstract 5564: QLS31901, a novel bifunctional anti-PD-L1/TGF-β fusion protein for treatment of solid tumors
Authors: Jiang Jiahua , Han Cuicui , Chen Qi , Wu Yun , Yan Xiaodan , Cao Ping
Published: June 2022

Immunosuppressive pathway blocking antibodies (e.g., anti-programmed death ligand 1 [PD-L1] antibodies) are effective and feasible cancer therapy, but some patients have poor individual drug responses to this class of drugs. Simultaneous targeting other immunosuppressive pathways is therefore a novel method to enhance the efficacy. While the antitumor activity of bifunctional anti-PD-L1/transforming growth factor-β (TGF-β) fusion protein bintrafusp alfa (M7824) in preclinical studies is well known, clinical studies to date with M7824 have led to limited success. QLS31901 is another bifunctional fusion protein composed of the truncated extracellular domain of the TGF-β receptor II fused to the C-terminus of humanized anti-PD-L1 heavy chain (αPD-L1) with function as a “trap” for all three TGF-β isoforms and the blockage of PD-L1 immunosuppressive pathway. The present study demonstrated its superior antitumor activity over M7824 in a humanized MDA-MB-231 model. Furthermore, toxicology studies of QLS31901 only showed a transient interleukin 6 elevation. There were no other cytokine release and organ toxicity in cynomolgus monkeys. Overall, these data provided a rationale for an expansion cohort study of QLS31901 for the treatment of patients with solid tumors and dual blockade of TGF-β as well as PD-L1 with QLS31901 may be a promising therapy.

Citation Format: Jiahua Jiang, Cuicui Han, Qi Chen, Yun Wu, Xiaodan Yan, Ping Cao. QLS31901, a novel bifunctional anti-PD-L1/TGF-β fusion protein for treatment of solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5564.
Abstract 5575: Pre-clinical validation of a LGR5-targeting CAR-T against colorectal cancer
Authors: Bandara Veronika , Mills Stuart , Thompson Emma , Tan Lih , Gundsambuu Batjargal , Napoli Silvana , Foeng Jade , McPeake Dylan , Coombs Justin , Cowin Allison , Bonder Claudine , Sadlon Timothy , McColl Shaun , Barry Simon
Published: June 2022

Chimeric antigen receptor T cells (CAR-T) have demonstrated robust clinical activity against B-cell malignancies, and rapid translation to approval for use in man has inspired the search for CAR-T cells against solid tumors. Cancer stem cells are a small population of cells within a tumor that have the capacity to self-renew, differentiate, and initiate new tumors. Cancer stem cells are known to be resistant to chemotherapy and radiotherapy and are enriched in residual disease which allows relapse. Targeting cancer stem cells will reduce the tumors’ ability to generate new cells resulting in tumor remission. We have tested a novel CAR-T cell that has the potential to target cancer stem cells. Leucine-rich G protein-coupled receptor 5 (LGR5) expression is restricted to stem cell populations in multiple tissues in adults. In addition, LGR5 is a marker of cancer stem cells and LGR5+ cells are implicated in tumor progression and metastasis. We designed six lentiviral CAR-T constructs targeting the extra cellar domain of LGR5 with differing linker lengths and binding domain orientation, and tested gene delivery to purified human CD3 T cells and in vitro cytotoxicity. All constructs were expressed robustly (>90%), and four of six LGR5-targeting CAR-T cells showed significant antigen-specific cytotoxicity against colorectal cancer cell lines in vitro. We confirmed the on-target specificity of the LGR5 targeting CAR-T using a cell line over-expressing the LGR5 protein and antibody competition assays, which blocked cytotoxicity. Using optimized gene delivery and CAR-T manufacturing protocols, we generated pre-clinical scale batches of the four lead constructs to evaluate their potency in a pre-clinical colorectal cancer xenograft mouse model. Post expansion our cell products expressed markers of self-renewing naïve-like and central memory phenotype and three out of four LGR5-targeting CAR-T cells were able to significantly inhibit the growth of human colorectal tumors. These results suggest a CAR-T targeting LGR5 may provide long-term protection against tumor growth. Our data positions LGR5-targeting CAR-T therapy as a viable therapeutic for human metastatic colorectal cancer types with minimal off-target effects, which we now aim to test in human clinical trials.

Citation Format: Veronika Bandara, Stuart Mills, Emma Thompson, Lih Tan, Batjargal Gundsambuu, Silvana Napoli, Jade Foeng, Dylan McPeake, Justin Coombs, Allison Cowin, Claudine Bonder, Timothy Sadlon, Shaun McColl, Simon Barry. Pre-clinical validation of a LGR5-targeting CAR-T against colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5575.
Abstract 5581: A genetically modified tumor-infiltrating lymphocytes product (GT202) exhibits enhanced persistence and anti-tumor efficacy against solid tumor in vivo
Authors: Sun Jingwei , Jin Jiahui , Tan Yongchao , Chen Lingyun , Wang Quanwei , Liu Yarong
Published: June 2022

Adoptive cell therapy by tumor-infiltrating lymphocytes (TILs) has demonstrated significant clinical benefits for patients with solid tumors. However, the toxicities related to high-dose IL-2 that is required to support TIL survival and the exhaustion status of the final TIL product after rapid expansion in culture largely limits the clinical application and long-term efficacy of TIL therapy. Grit Biotechnology designed a genetically engineered TIL product (GT202) to express a membrane-bound cytokine that is critical for T cell activation and effector function, leading to enhanced cytotoxicity as well as persistence in vitro and in vivo. Multiple designs of the transmembrane domain of GT202 were compared and the best design was selected based on stable and efficient expression of GT202 on the membrane of TILs. GT202 demonstrated significantly increased cytotoxicity and cytokine production when cocultured with tumor cells in vitro than conventional TILs and better tumor control ability during a serial killing assay. In the meanwhile, GT202 TILs showed enhanced long-term survival and better preservation of TCR clonality without IL-2 in vitro, as well as persisted longer in multiple tissues without IL-2 over conventional TILs + IL-2 in NGS mice. Notably, GT202 TILs achieved better anti-tumor efficacy with low IL-2 in NSG mice inoculated with HLA-matched tumor cells than conventional TILs, corelated with their better infiltration and proliferation in spleen and tumor. In summary, GT202 demonstrated enhanced anti-tumor efficacy and persistence as well as decreased IL-2 dependency in vitro and in vivo. Currently, an investigator-initiated trial of GT202 is ongoing in China.

Citation Format: Jingwei Sun, Jiahui Jin, Yongchao Tan, Lingyun Chen, Quanwei Wang, Yarong Liu. A genetically modified tumor-infiltrating lymphocytes product (GT202) exhibits enhanced persistence and anti-tumor efficacy against solid tumor in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5581.
Abstract 5619: Co-occurrence ofLactobacillusandCandida sp.in periodontal disease severity suggests cancer-related dysbiosis
Authors: Acosta-Pagán Kimil T. , Godoy-Vitorino Filipa , Bolaños-Rosero Bejamín , Ortíz Ana P. , Oramas-Sepúlveda Carla , Pérez Cynthia M. , Vivaldi-Oliver José A. , Pérez-Santiago Josué , Castañeda-Avila Maira
Published: June 2022

Introduction: Microbiota plays an essential role in the oral cavity and oral dysbiosis, leading to inflammatory diseases such as periodontitis. Periodontal disease is associated with a two-fold increase in the risk of oral cancer; thus, evaluating polymicrobial associations across a gradient of periodontitis will help understand the microbial processes that could influence cancer development. We aimed to study the association of oral bacteria and fungi linked to high-risk behavior and periodontal disease.

Methods: This cross-sectional study recruited individuals aged 21 to 49 from sexually transmitted infection clinics in Puerto Rico. A total of 88 participants underwent a full-mouth periodontal examination following the NHANES protocol. Periodontal severity was defined according to the CDC/AAP. Saliva was collected for genomic DNA extraction, and downstream 16S V4 and ITS-2 genes were amplified, sequenced, and analyzed with standard bioinformatics pipelines.

Results: Nearly 29% of individuals had some degree of periodontal disease. Bacterial community analyses revealed differences in both composition and diversity as the periodontal disease progressed. The predominance of Prevotella and Veillonella in the salivary microbiota was attributed to periodontal conditions with low levels of Lactobacillus in patients with severe disease. In contrast, the predominance of Neisseria was related to healthy participants. Fungal communities changed in composition with disease severity, including the dominance of Candida tropicalis. Co-occurrence analyses revealed that Lactobacillus co-occurred with Candida dubliniensis, C. tropicalis, and Saccharomyces cerevisiae in individuals with periodontal disease.

Conclusion: Co-occurrence patterns of bacteria and fungi changed from participants with no disease to periodontal severity. Lactobacillus has been identified in caries, xerostomia, and saliva of HPV-positive head and neck cancer patients. This study is the first to report the co-occurrence of this Lactobacillus with oral candidiasis in periodontal severity. We expect that these biofilms induce inflammation in periodontal pockets while also making them more resistant to treatments.

Citation Format: Kimil T. Acosta-Pagán, Filipa Godoy-Vitorino, Bejamín Bolaños-Rosero, Ana P. Ortíz, Carla Oramas-Sepúlveda, Cynthia M. Pérez, José A. Vivaldi-Oliver, Josué Pérez-Santiago, Maira Castañeda-Avila. Co-occurrence ofLactobacillusandCandida sp.in periodontal disease severity suggests cancer-related dysbiosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5619.
Abstract 5654: Degradation of Bcl-xL by DT2216 is lethal to T-cell acute lymphoblastic leukemia
Authors: Jaiswal Arunima S. , Williamson Elizabeth , Hromas Robert A. , Zhou Daohong
Published: June 2022

Cancer is a multistep process where genomic and epigenomic alterations results in abnormal cellular proliferation and dissemination. This unregulated cellular proliferation can be interrupted through intervention therapy. One such strategy utilizes proteolysis targeting chimeras (PROTACs). PROTACs are heterobifunctional small molecular structures consisting of a ligand that binds to a target protein, and upon binding can recruit an E3 ligase which ubiquitinates the target protein, and eventually directs ubiquitinated protein for proteasomal degradation. This has been exploited as a revolutionary therapeutic strategy to degrade oncogenic and/or anti-apoptotic protein(s) that are overly expressed and offer a growth advantage in actively growing tumors. The accumulation of anti-apoptotic proteins creates resistance within the tumor against cancer treatments and preventative strategies in the clinical setting. In the present study, we used DT2216, a PROTAC that targets and promotes degradation of the anti-apoptotic protein Bcl-xL via the VHL (E3 ligase) pathway in T-cell acute lymphoblastic leukemia cells (T-ALL). Unlike other preclinical studies, like ABT263, DT2216 does not cause thrombocytopenia because VHL is poorly expressed in platelets. In our preclinical study, we treated thirteen human T-ALL cells with varying concentrations of DT2216 (0-1 µM) for 24 h and analyzed Bcl-xL expression by western blot analysis. Our data suggests that DT2216 results in the robust degradation of Bcl-xL in a dose-dependent manner at a minimal dose of 10 nM in eight of the cell lines studied (ALL-SIL, P12-Ichikawa, Jurkat, SUP-T1, HBP-ALL, HSB-2, PEER, and DND-41). Bcl-xL degradation triggers apoptosis, which was evident through the presence of cleaved products for Caspase-3 and PARP-1. We examined the expression of other anti-apoptotic proteins, Bcl-2 and Mcl-1 in response to DT2216 and neither protein was changed, which highlights DT2216’s specificity. We further evaluated the effect of DT2216 on the survival of T-ALL cells. Our data suggests that the IC50 for all the T-ALL cell lines ranges from 2-100 nM, with the exception of SUP-T1, which exhibited an IC50 above 1 µM. Our data suggests that DT2216 could serve as a viable, safe, and potent alternative or addition to traditional clinical treatments of T-ALL.

Citation Format: Arunima S. Jaiswal, Elizabeth Williamson, Robert A. Hromas, Daohong Zhou. Degradation of Bcl-xL by DT2216 is lethal to T-cell acute lymphoblastic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5654.
Abstract 5667: EZH2 inhibition targets B7-H3 in Myc amplified medulloblastoma
Authors: Shishido Katherine , Venkataraman Sujatha , Vibhakar Rajeev , Velpula Kiran , Asuthkar Swapna
Published: June 2022

Medulloblastoma (MB) is the most common malignant pediatric brain tumor. The most aggressive MB subtype Group 3, is characterized by Myc amplifications. However, targeting Myc has proven unsuccessful, necessitating alternative therapies for MB. The histone methyltransferase, enhancer of zeste homolog 2 (EZH2), is well-known for its role in catalyzing the tri-methylation of H3K27 (H3K27me3). Recent studies have demonstrated that EZH2 is overexpressed in Group 3 MB and that Myc and EZH2 regulate the expression of the B7 homolog 3 (B7-H3). As we previously showed the oncogenic functions of B7-H3 in Group 3 MB, this study aims to investigate the efficacy of EZH2 inhibition to reduce B7-H3 levels in an effort to improve treatment options and patient survival. Datamining studies conducted using MB patient datasets showed a positive correlation between EZH2 and B7-H3 transcripts. Additionally, we showed that inhibition of EZH2 using EPZ005687 in Myc-amplified MB cell lines downregulated B7-H3 and Myc expression. Furthermore, targeting EZH2 through shRNA and pharmacological inhibition reduced the viability and augmented apoptosis, as indicated by LDH, MTT, clonogenic, and FACS assays. We additionally tested the consequences of EZH2 inhibition on the C17.2, murine neural stem cells, and C17.2 NSC transformed with EZH2 oncogene (C17.2_EZH2OX). Furthermore, the C17.2_EZH2OXcells were susceptible to EPZ005687 treatment compared to C17.2 control cells, as demonstrated by MTT and FACS. Collectively, our study highlights the therapeutic benefits of targeting EZH2 in Myc-amplified MB cell survival.

Citation Format: Katherine Shishido, Sujatha Venkataraman, Rajeev Vibhakar, Kiran Velpula, Swapna Asuthkar. EZH2 inhibition targets B7-H3 in Myc amplified medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5667.
Abstract 5679: Application of a hypoxia metric to investigate tumor mutational burden and cancer cell immunogenicity in vitro
Authors: Khouzam Raefa Abou , Zeinelabdin Nagwa Ahmed , Sharda Mohak , Nawafleh Husam , Mahmood Ayda shah , Khan Munazza Samar , Venkatesh Goutham Hassan , Chouaib Salem , Rao Shyama Prasad
Published: June 2022

Hypoxia afflicts the microenvironment of solid tumors fueling tumor malignancy. Using an 8-gene in vitro hypoxia signature, we have recently shown that pancreatic cancer patients with highly hypoxic tumors experience worse survival and exhibit markers of an immunosuppressed microenvironment. Simultaneously, we obtained evidence of increased mutation count in more hypoxic tumors, which accommodates previous reports associating hypoxia with the regulation of tumor mutational burden (TMB) and genomic instability. These two features could enhance tumor immunogenicity by increasing neoantigen expression, enabling immune recognition and tumor eradication. In this work our aim is to further elucidate the underlying role of hypoxia in generating TMB and genomic instability, and how it contributes to cancer cells immunogenicity. To this end, we applied our recently identified 8-gene hypoxia signature to score the hypoxic response of different cancer cells, considering their median expression levels of the signature genes upon exposure to hypoxia (1% oxygen). The hypoxia score was then applied as a metric to distinguish between the highest and lowest scoring cells, enabling a novel approach for evaluating the intrinsic impact of hypoxia on immunogenicity. After twenty passages under hypoxic conditions (1% oxygen), scored cancer cells were subjected to whole exome sequencing (WES) using the Ion Chef System. Following data processing using appropriate bioinformatic tools, variants were called in the hypoxia-treated cells using their normoxic (21% oxygen) counterparts as controls. We first demonstrated that hypoxia induced an increase in TMB in all cell lines. More interestingly, higher scoring cells were found to display, on average, higher TMB than lower scoring cells, suggesting that cells that have a lower hypoxia score tend to be less mutable. Copy number alterations, mutational signature and neoantigen load predictions generated from the WES data will be discussed. The microarray analysis of transcriptomic data from these hypoxia-treated cells, as well as the relationship between the high TMB, high neoantigen load and increased activation of immune response pathways will also be illustrated.

Citation Format: Raefa Abou Khouzam, Nagwa Ahmed Zeinelabdin, Mohak Sharda, Husam Nawafleh, Ayda shah Mahmood, Munazza Samar Khan, Goutham Hassan Venkatesh, Salem Chouaib, Shyama Prasad Rao. Application of a hypoxia metric to investigate tumor mutational burden and cancer cell immunogenicity in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5679.
Abstract 5700: Increasing efficacy of iBET-151, a small molecule inhibitor of BET protein in combination with paclitaxel in gastric cancer
Authors: Kang Sun Kyoung , Cho Sang Woo , Kwon Woo Sun , Kim Tae Soo , Chung Hyun Cheol , Rha Sun Young
Published: June 2022

Epigenetic dysregulation is a common characteristic of cancers, including gastric cancer (GC), which contributes to the development and progression of GC. BRD4 is one of the leaders for epigenetic regulation and is known to regulate the expression of oncogenes such as c-MYC, BCL-2, and CDK4. In a previous study, we evaluated the efficacy of iBET-151 in a large panel of GC cell lines and xenograft mouse models. We found that iBET-151 showed a modest growth-inhibitory effect in GC cells. Recent report showed, lowering the expression of BCL-2 and BCL-xL, which are the targets of BRD4, induces sensitivity to paclitaxel, frequently used antimitotic agent in GC. Therefore, we evaluate iBET-151 plus paclitaxel as a new combination treatment regimen for GC. The synergistic effect and possible mechanisms of iBET-151 with paclitaxel were evaluated in 49 GC cell lines or 10 GC organoids using cell proliferation assay, flow cytometry, western blotting, colony formation, and migration assays. We found that the addition of iBET-151 increased the sensitivity to paclitaxel alone treatment from 15% to 50% in approximately 70% (34/49) of GC cells. iBET-151 plus paclitaxel significantly promoted cell-cycle arrest at G1 or G2/M phase and increased sub-G1 phase and cleaved PARP expression, which correlates to increased cell death. Also, combined treatment suppressed c-Myc, Bcl-2, and Bcl-xL expression in AGS, YCC-1, YCC-32, and YCC-34. We found BET proteins were overexpressed in most patient-derived GC organoids whereas c-Myc, BCL-2, and BCL-xL were expressed at variable levels. We observed that there was a synergistic growth inhibition in 6 out of 10 (60%) organoids. The data suggests iBET-151 and paclitaxel have a synergistic effect not only in GC cell lines but also in GC organoids. In summary, our data show the combination of iBET-151 and paclitaxel resulted in markedly higher anti-tumor effects compared with either treatment alone for GC. With further studies to validate the efficacy and biomarker explorations, the combination of iBET-151 and paclitaxel represents a promising therapeutic strategy in GC.

Citation Format: Sun Kyoung Kang, Sang Woo Cho, Woo Sun Kwon, Tae Soo Kim, Hyun Cheol Chung, Sun Young Rha. Increasing efficacy of iBET-151, a small molecule inhibitor of BET protein in combination with paclitaxel in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5700.
Abstract 5702: Cancer-specific glycosylation regulated by epigenomic alteration in renal cell carcinoma
Authors: Kitazume Yoshiko , Arai Eri , Matsuda Atsushi , Ohara Kentaro , Maeshima Akiko Miyagi , Yoshida Teruhiko , Kuno Atsushi , Kanai Yae
Published: June 2022

Background and Aims: Cancer-specific glycosylation plays an important role in the development and progression of cancer. Epigenetics may contribute to forming cancer-specific glycosylation by regulating the expression of glycogenes. Although comprehensive analysis of epigenetics is routinely performed, comprehensive glycan analysis, especially using human clinical samples, has been limited due to technical underdevelopment. Our aims are to understand the significance of glycosylation and its epigenetic regulation on renal carcinogenesis and to identify cancer-specific glycosylation as a potential diagnostic marker and a novel therapeutic target.

Materials and Methods: Comprehensive glycomics and methylome analysis were performed by lectin microarray and Infinium HumanMethylation450 BeadChip on 50 non-cancerous renal cortex tissue (N) and 50 clear cell renal cell carcinoma (RCC) (T) microdissected from formalin-fixed and paraffin-embedded tissue samples.

Results: Compared to N samples, T samples showed higher fluorescence intensity for lectins recognizing mannose-type glycans, and lower intensity for lectins recognizing sialyl and fucosyl groups. In RCC, the metabolism of N-glycans may remain in an immature state. By hierarchical clustering using lectin microarray data, T samples were divided into Clusters A and B with significant differences in patients’ outcome. Increased high-mannose type N-glycan and core fucosylation and decreased sialylation were observed in T samples of Cluster A. According to these results, glycosylation profiles showed heterogeneity associated with patients’ outcome among RCCs, and immature N-glycan may be specific in some RCCs. Methylome analysis suggests that specific glycosylation profiles of RCCs may be induced by DNA methylation alteration on glycogenes. Association between DNA methylation and mRNA expression was confirmed on some glycogenes using real-time reverse transcription PCR. As a result of examining whether the signal intensity pattern of each lectin reflects the prognosis of clear cell RCC, we could identify the lectins that reflect the RCCs prognosis.

Conclusion: In RCC, the metabolism of N-glycans may remain in an immature state. The glycan profiles show heterogeneity among individual RCCs, and some of the specific glycan profiles may be associated with patients’ outcome. Cancer-specific glycan profiles may be regulated by epigenetic alteration of glycogenes.

Citation Format: Yoshiko Kitazume, Eri Arai, Atsushi Matsuda, Kentaro Ohara, Akiko Miyagi Maeshima, Teruhiko Yoshida, Atsushi Kuno, Yae Kanai. Cancer-specific glycosylation regulated by epigenomic alteration in renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5702.
Abstract 5728: A druggable FOXA1-glucocorticoid receptor transcriptional axis drives tumor growth in NSCLC
Authors: Dorso Madeline
Published: June 2022

FOXA1 is a pioneer factor that is essential to steroid receptor function in hormone-dependent adenocarcinomas, including breast and prostate cancer. FOXA1 expression is also observed in other tumors of epithelial lineage such as non-small cell lung cancer (NSCLC), but whether and how it is required for tumor growth in these contexts is not known. Analyzing data from genome-scaled pooled loss-of-function screens, we identified and validated a subset of NSCLC cell lines with reduced cellular fitness following FOXA1 knockout. We performed a rapid immunoprecipitation and mass spectrometry of endogenous proteins (RIME) screen to nominate candidate factors that may cooperate with FOXA1 to mediate oncogenic transcription programs. This screen revealed a chromatin-localized interaction between FOXA1 and the glucocorticoid receptor (GR). Depletion of GR expression using shRNA or CRISPR/Cas9 suppressed the proliferation of FOXA1-dependent, but not FOXA1-independent NSCLC models, suggesting GR specifically contributes to tumor growth in the FOXA1-dependent context. To assess the potential therapeutic utility of targeting the FOXA1-GR signaling axis, we employed two structurally distinct ligand antagonists of GR from ORIC Pharmaceuticals: ORIC-101, a steroidal antagonist, and OP-4954, a non-steroidal antagonist. Both antagonists inhibited dexamethasone stimulated GR-transactivation of a glucocorticoid response element (GRE)-luciferase reporter with equal potency. However, proliferation and colony formation of the FOXA1/GR-dependent NSCLC cells were only inhibited upon treatment with ORIC-101, and not OP-4954. Gene expression analysis uncovered a discrete set of GR target genes, including SFTPB, TRAF4 and SGK1, whose expression was reduced by ORIC-101 but unaffected or even induced by OP-4954. The specific inhibition of GR target gene expression and attendant induction of apoptosis by ORIC-101 suggest a hierarchy of GR targets relevant to the FOXA1/GR-growth program in NSCLC. Finally, we evaluated the in vivo therapeutic potential of ORIC-101 using NSCLC xenografts and found that single-agent ORIC-101 exhibited potent antitumor effects in these models. Taken together, these data establish a model of FOXA1-GR-dependent tumor growth amongst a subset of NSCLCs and demonstrate that effective blockade of this complex is a rational therapeutic avenue to be explored in the clinic.

Citation Format: Madeline Dorso. A druggable FOXA1-glucocorticoid receptor transcriptional axis drives tumor growth in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5728.
Abstract 5750: Quantification of histone methylation regulator-associated modification patterns was a potential biomarker for prognosis and associated with immunotherapy in gastric cancer
Authors: Kang Jiapeng , Yang Lu , Lin Jialin , Zhou Dan , Fang Canbin , Ye Feng , Tang Weiwei
Published: June 2022

Background: Histone methylation (HM) is an abundant form of histone modification and recent studies have highlighted it strongly related to tumorigenicity and progression. However, histone methylation modification patterns and potential roles in gastric cancer have not been systematically elucidated.

Method: In this study, we curated 53 histone methyltransferase regulators and 9 histone demethylase regulators. Identified histone methylation(HM)modification clusters based on the expression of 62 HM regulators. Principal component analysis (PCA) served to construct histone methylation score (HMScore) base on differential genes among three HM clusters. Evaluating the relationship between HMScore and clinical prognosis, tumor mutation burden (TMB), microsatellite instability (MSI), immune cell infiltration and immunotherapy.

Results: We identified distinct three HM modification clusters in patients with gastric cancer based on the expression of 62 HM regulators, which were association with different clinical prognosis, biological pathways and tumor microenvironment characterization. Based on HMScore to quantitatively evaluate the histone methylation modification patterns in gastric cancer patients. We founded that patients with a low-HMScore group(score<2.276) was association with poor prognosis. In addition, high-HMScore group(score≥2.276) displayed tumor mutation burden-high (TMB-H) and microsatellite instability-high (MSI-H), and correlation analysis indicated that HMScore was positively correlated with tumor mutation burden. Immune infiltration correlation analysis showed that HMScore strongly negative related to MDSC cell, mast cell and regulatory T cell. Survival analysis indicated that patients with TMB-H and high-HMScore were related to long clinical prognosis in gastric cancer. Moreover, patients with high-HMScore group had high abundance of PD-L1, and high-HMScore was confirmed sensitive response to immunotherapy in gastric cancer.

Conclusion: This study provided a new model to evaluate individual gastric cancer histone methylation modification patterns. HMScore was benefit to evaluate clinical prognosis value and guide strategies to improve treatment in gastric cancer.

Citation Format: Jiapeng Kang, Lu Yang, Jialin Lin, Dan Zhou, Canbin Fang, Feng Ye, Weiwei Tang. Quantification of histone methylation regulator-associated modification patterns was a potential biomarker for prognosis and associated with immunotherapy in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5750.