bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3993: A tunable safety switch for solid tumor CAR T-cell therapy
Authors: Misawa Kyohei , Taleb Meriem , Banerjee Srijita , Vista William-Ray , Chintala Navin K. , Adusumilli Prasad S.
Published: March 2024

On-target off-tumor toxicity, cytokine release syndrome (CRS), and immune effector cell-associated neurotoxicity syndrome (ICANS) are severe immune-related adverse events (irAEs) that are frequently associated with Chimeric Antigen Receptor (CAR) T-cell therapy. Current efforts to manage such therapy-related toxicities involve incorporation of an inducible suicide agent within CAR constructs, such as iCaspase-9 or herpes simplex virus type 1 thymidine kinase that can be selectively activated to produce toxic effects within CAR T cells and attenuate their activity. However, while activation of these agents helps to mitigate or overcome such unwarranted toxicities, the therapeutic benefit of CAR T cells anti-tumor activity is also compromised. Therefore, to continue maintenance of CAR T cells’ therapeutic function while minimizing irAEs, an ideal safety switch should 1) rapidly inhibit the activation and proliferation of CAR T cells exposed to the target antigen, 2) reversibly inhibit activity without inducing CAR T cell elimination and 3) be clinically translatable for safe application in patients. Our laboratory investigated one such safety switch to inhibit CAR T-cell activity while maintaining their therapeutic function. We showed that incorporating a mutant variant of c-KIT D816V (KITv) in the intracellular domain of mesothelin-targeting second-generation CAR T cells (M28z-KITv) improved efficacy in solid tumors with low antigen, or an immunosuppressive environment. Herein, we evaluate the use of Dasatinib, a clinically available multitarget (BCR, SRC, c-KIT) tyrosine kinase inhibitor (TKI), as a tunable safety switch to reversibly inhibit M28z-KITv CAR T-cell functional activity. In cohorts of mice established with lung adenocarcinoma, daily administration of Dasatinib starting on day 1 or day 3 after CAR T-cell administration stabilized tumor growth, which otherwise continued to regress in untreated mice, indicating inhibition of CAR T-cell functional activity. Upon discontinuation of Dasatinib, tumors regressed, indicating reversal of CAR T-cell functional activity. In an experiment conducted to investigate functional persistence of CAR T cells upon long-term exposure to Dasatinib (1 month), we noted uninhibited activity of CAR T cells to rechallenged tumors. Dasatinib, thus may act as a tunable safety switch to regulate M28z-KITv CAR T-cell activity without compromising its therapeutic function.

Citation Format: Kyohei Misawa, Meriem Taleb, Srijita Banerjee, William-Ray Vista, Navin K. Chintala, Prasad S. Adusumilli. A tunable safety switch for solid tumor CAR T-cell therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3993.
Abstract 4011: Locoregional GPC3 chimeric antigen receptor (CAR)-T cell therapy is associated with improved tumor control in hepatocellular carcinoma by enhancing CAR-T cell trafficking and functionality
Authors: Wang Jue , Tsang Kinching , Qiu Jiale , Feng Bo
Published: March 2024

Despite the rapid development of anti-cancer immunotherapy, the prognosis of hepatocellular carcinoma (HCC) patients is far from satisfactory. Glypican-3 (GPC3) CAR-T cell therapy has shown varied patient response. One of the potential reasons of low response rates may be due to the limited CAR-T cell infiltration. Therefore, locoregional GPC3 CAR-T therapy has been a promising option, with a hope of enhancing CAR-T cell tumor penetration. In this study, the therapeutic efficacy and underlying mechanisms of locoregional GPC3 CAR-T cell delivery were explored using HCC mouse xenografts. Orthotopic NOD-scid IL2Rgnull (NSG) HCC models were established by tumor fragment implantation into the liver. CAR-T cell injections were performed via the tail vein and portal vein to simulate systemic and locoregional administrations, respectively. Compared to the systemic treatment, locoregional therapy could better control the tumor growth, and was associated with improved liver function. In addition, the locoregional therapy group demonstrated a higher percentage of tumor-infiltrating CAR-T cells which showed an increased expression level of the cytotoxicity marker GZMB and a reduced level of the exhaustion marker LAG3. Moreover, significantly higher IFN-gamma level was found in the blood of the locoregional therapy group, indicating a better CAR-T cell functionality. In conclusion, we have demonstrated that locoregional administration of CAR-T cells is associated with increased CAR-T cell infiltration and better therapeutic efficacy. Additionally, CAR-T cells being injected locoregionally are correlated with enhanced functionality and reduced exhaustion phenotype. These findings highlight the potential of locoregional GPC3 CAR-T therapy as a promising treatment strategy for HCC patients.

Citation Format: Jue Wang, Kinching Tsang, Jiale Qiu, Bo Feng. Locoregional GPC3 chimeric antigen receptor (CAR)-T cell therapy is associated with improved tumor control in hepatocellular carcinoma by enhancing CAR-T cell trafficking and functionality [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4011.
Abstract 4019: Development of mRNA chimeric antigen receptor T cells targeting MET in aggressive B-cell lymphomas
Authors: Chen Po-Han , Raghunandan Rianna , Muschen Markus , Katz Samuel G.
Published: March 2024

Multiple versions of CAR T cells targeting the cell surface protein CD19 are approved by the FDA to treat refractory B-cell malignancies. However, durable remissions range from 60% in B-cell leukemias to 40% in B-cell lymphomas. Major reasons for resistance to CD19-CAR treatment relate to heterogeneous or loss of CD19 expression. In addition, CD19-CAR leads to B-cell depletion which increases the risk for infection. These limiting factors necessitate research into alternative targets for CAR therapy against B-cell lymphomas.Using a large data set from clinical trials, we found that approximately 30-70% of diffuse large B-cell lymphomas (DLBCL) express MET. We hypothesize that these MET-positive B-cell lymphomas can potentially be targeted with chimeric antigen receptor (CAR) T-cells against MET receptor. We constructed a second-generation anti-MET-CAR by fusing the scFv fragment of an anti-MET monoclonal antibody with the human CD28 hinge/transmembrane/cytoplasmic domain and CD3ζ cytoplasmic domain. Stable MET-CAR Jurkat cells showed increased CD69 expression upon stimulation by MET-positive lymphoma cell lines such as Karpas-422 and OCI-LY3. Using primary human T cells, we further demonstrated that the mRNA MET-CAR T-cells mediated cytotoxicity against DLBCL cell lines. Of note, while CD19-CAR T-cells showed only low level of cytotoxicity against the CD19-/MET+ OCI-LY3 cell line, MET-CAR T cell was able to mediate substantial tumor cell lysis.In summary, the preliminary data demonstrate that MET-CAR is capable of mediating cytotoxicity against MET-positive DLBCL. Some cell lines such as OCI-LY3 are negative for CD19 but positive for MET expression, and MET-CAR is capable of mediating cell lysis while CD19-CAR is ineffective. These results suggest that some large B-cell lymphomas negative for CD19, either intrinsic or secondary to loss of CD19 as a result of resistance mechanism, may show MET expression and will likely benefit from MET-targeted immunotherapy.

Citation Format: Po-Han Chen, Rianna Raghunandan, Markus Muschen, Samuel G. Katz. Development of mRNA chimeric antigen receptor T cells targeting MET in aggressive B-cell lymphomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4019.
Abstract 4021: The development of CAR T cell therapeutics targeting tumor specific CD146
Authors: Uzuner Erez , Mole Holly , Wong Chun W. , Carro Macarena L. Fernandez , Leshem Rotem , Sefton Kieran , Tovey Helen , Picken Andrew , Blot-Chabaud Marcel , Hurlstone Adam F.
Published: March 2024

Chimeric antigen receptor (CAR) T cells represent a promising class of "living drugs" for cancer treatment. These primary T cells are genetically engineered to express a synthetic antigen receptor, incorporating various domains to enhance their effector functions. While CAR T cells have shown success against liquid cancers, their application to solid cancers is hindered by significant "on-target/off-tumor" toxicities due to the absence of specific target proteins. In this study, we aim to enhance the tumor specificity of CAR T cells by targeting a tumor-specific version of CD146. CD146 is a glycoprotein widely expressed in several solid tumors, particularly melanoma and ovarian cancer. However, it is also expressed on benign cells, such as endothelial cells, pericytes, and smooth muscle cells. Nevertheless, a CD146 isoform exists that is enriched in cancer cells.

We assessed CAR activity using flow cytometry to measure surface CD69 expression (an early activation marker) on CAR-expressing Jurkat cells co-cultured with various CD146-positive and CD146-negative human melanoma and ovarian cancer cell lines. The killing ability of primary CAR-T cells was evaluated by measuring the relative luciferase activity of target cells, and their effector functions were further analyzed by ELISA for the secretion of IFN-g and TNF-a.

Through multiple rounds of protein engineering, we have developed a CAR construct capable of reprogramming T cells to respond to a tumour-enriched CD146 isoform. Our CAR demonstrated antigen-dependent activation of Jurkat cells when co-cultured with CD146-positive human melanoma and ovarian cancer cell lines, comparable to a CAR targeting pan-CD146. Moreover, primary CAR T cells exhibited proportional killing activity and other effector functions.

We have successfully engineered a CAR with specificity for a tumour-enriched isoform of CD146. Our future work will involve rigorously evaluating the tumor selectivity of our CAR, as well as assessing the ability of primary CAR T cells expressing this CAR to control tumor growth in vivo.

Citation Format: Erez Uzuner, Holly Mole, Chun W. Wong, Macarena L. Fernandez Carro, Rotem Leshem, Kieran Sefton, Helen Tovey, Andrew Picken, Marcel Blot-Chabaud, Adam F. Hurlstone. The development of CAR T cell therapeutics targeting tumor specific CD146 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4021.
Abstract 4026: The combination of DLL4/VEGF-a blockade and immunomodulation can eliminate MHC class I negative tumors in mice
Authors: Albu Diana I. , Duffy Rachael , Ulumben Amy Daniel , Kong Jason , Zolotarevsky Jessica , Brundin Melissa , Su Mei , Jadhav Ruturaj , Sachsenmeier Kris F. , Gong Bing , Schuetz Thomas J. , Visintin Alberto
Published: March 2024

CTX-009 is a bispecific antibody targeting VEGF-A and DLL4 which is undergoing clinical investigation in patients with multiple tumor types, including biliary tract and colon cancers. In biliary tract cancers, checkpoint inhibitor therapy has been shown to improve outcomes when combined with chemotherapy. In an effort to increase the breadth and duration of response of CTX-009, we set out to investigate the combined anti-tumor efficacy of this bispecific antibody and immunotherapy in preclinical models. Here we report the evaluation of the combination of the mouse surrogates of CTX-009 and CTX-471, an agonistic anti-mouse CD137 antibody, or monoclonal antibodies that disrupt the PD-1/PD-L1 signaling axis. Coupling VEGF-A/DLL4 targeting with either CD137 agonism or PD-1/PD-L1 blockade markedly increased the anti-tumor efficacy of the individual treatments alone in multiple syngeneic mouse tumor models. Tumor growth inhibition was accompanied by pharmacodynamic evidence consistent with enhancement of anti-tumor immunity. Notably, the combination of CTX-009 and CTX-471 retained potent anti-tumor activity even in a tumor line (MC38) which was made MHC I deficient through the deletion of the beta 2 microglobulin gene. This system may model the clinically relevant unmet need characterized by tumor escape through the loss of antigen presentation machinery such as HLA LOH. Interestingly, the model cell lines CT26 and MC38 failed to thrive in the B2M-deficient setting and depletion of NK cells markedly increased their ability to grow. This implies that NK cells might be involved in controlling tumor growth in this setting, and that the combined action of CTX-471 and CTX-009 in the tumor stroma enhances NK cell activity. The findings presented here suggest that CTX-009 may provide enhanced clinical benefit when combined with immunomodulatory agents, such as agonistic anti-CD137 antibodies or PD-1/PD-L1 blockers in tumors where immune checkpoint inhibitors have failed. 

Citation Format: Diana I. Albu, Rachael Duffy, Amy Daniel Ulumben, Jason Kong, Jessica Zolotarevsky, Melissa Brundin, Mei Su, Ruturaj Jadhav, Kris F. Sachsenmeier, Bing Gong, Thomas J. Schuetz, Alberto Visintin. The combination of DLL4/VEGF-a blockade and immunomodulation can eliminate MHC class I negative tumors in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4026.
Abstract 4043: Nanoparticle-mediated combination therapy to synergistically harness Type I interferons and senescence in the pancreatic tumor microenvironment
Authors: Atukorale Prabhani , Ruscetti Marcus , Chibaya Loretah , Lusi Christina , DeMarco Kelly , Kane Griffin , Brassil Meghan , Parikh Chaitanya , Murphy Katherine
Published: March 2024

We seek to combine a unique innate immunomodulatory nanoparticle (NP) system with RAS inhibitors for a multi-faceted therapy that mitigates the formidable drug delivery challenges in pancreatic ductal adenocarcinoma (PDAC). PDAC has quickly risen to the third most deadly cancer largely due to its fibrotic, desmoplastic, and immunosuppressive tumor microenvironment (TME) that limits delivery and efficacy of chemo- and immunotherapeutics. We have engineered unique lipid-based NPs that co-encapsulate agonists of the Stimulator of Interferon Genes (STING) and Toll-like Receptor 4 (TLR4) pathways. NPs can be safely delivered in the systemic blood circulation to achieve TME deposition, uptake by innate antigen-presenting cells (APCs), and robust, synergistic production of Type I interferons by dual STING/TLR4 activation. Here, we hypothesize that combination therapy of proinflammatory NPs with tumor senescence-inducing RAS inhibitors, tremetinib and palbociclib, will not only augment CD8+ T cell recruitment to the TME but enhance their sustained activation by mitigating local immunosuppression. In mice bearing orthotopic transplant KPC tumors or KPC GEMMs, combination NP/inhibitor treatment promoted significant NP delivery to tumors, APC and natural killer (NK) cell activation, and CD8+ T cell-mediated clearance, compared to monotherapies and untreated controls. Unexpectedly and strikingly, these studies also showed that, besides innate immune cells, combination therapy also promoted Type I interferon and other proinflammatory cytokine production by PDAC tumor cells, which are otherwise notoriously unresponsive to current state-of-the-art treatments. Further, in KPC GEMMs, 25% of mice exhibited apparent complete responses following combination treatment, which, to our knowledge, is challenging to achieve in this model. Current studies include the mechanistic elucidation of immune- and tumor-intrinsic factors that govern efficacy of our combination therapy. In conclusion, these findings strongly corroborate the use of this NP-based system as a platform therapy for similar drugs and across other aggressive cancers. They also strongly make the case for the rational design of combination therapies to achieve synergistic therapeutic outcomes with minimal systemic toxicities.

Citation Format: Prabhani Atukorale, Marcus Ruscetti, Loretah Chibaya, Christina Lusi, Kelly DeMarco, Griffin Kane, Meghan Brassil, Chaitanya Parikh, Katherine Murphy. Nanoparticle-mediated combination therapy to synergistically harness Type I interferons and senescence in the pancreatic tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4043.
Abstract 4052: Neutrophil recruitment and activation promotes cutaneous adverse effects with T cell immunotherapies
Authors: Hirschhorn Daniel , Kraehenbuehl Lukas , Budhu Sadna , Navarro Valeria Estrada , Mangarin Levi Mark B , Marouf Yacine , Ricca Jacob , Gasmi Billel , De Henau Olivier , Li Yanyun , Cortez Czrina , Linda Hamadene , Schulze Isabell , Liu Cailian , Panageas Katherine , Lacuoture Mario , Rizzuto Gabrielle A. , Egeblad Mikala , Wolchok Jedd D. , Merghoub Taha Merghoub
Published: March 2024

Immune-based therapies that induce tumor regression are often accompanied by immune-related adverse events (irAEs) which can occasionally present with severe and lethal symptoms. Currently, there are no well-defined preventative approaches to uncouple anti-tumor immunity from irAEs. Currently approved immunotherapies include agents that activate T cell responses, such as antibodies blocking immune checkpoints and infusion of tumor-derived, T cell receptor-transgenic or chimeric antigen receptor-modified T cells. While the beneficial and toxic effects of T cell-based therapies in the clinic are being extensively explored, the precise mechanisms underlying their activity remain the subject of investigation. In this study, we treated preclinical models of established melanomas with tumor-specific adoptive CD4+ T cell transfer in combination with T cell co-stimulation via OX40 agonism or CTLA-4 blockade. We found that, despite adequate T cell stimulation, acute local inflammation plays an important role in tumor elimination and the manifestation of irAEs. While stimulated T cells are necessary for initiating a therapeutic response, activation of endogenous neutrophils constitutes an important and necessary effector mechanism for both tumor destruction and the development of irAEs. Extensive neutrophil extracellular traps (NETs) were associated with irAEs. Furthermore, melanoma patients treated with immune checkpoint blockade with skin rashes equivalent to irAEs found in mice showed increased survival and NETs in biopsies from both rashes and tumors. Our results bring forward a novel paradigm where T cells prime an anti-tumor immune response that is followed by an inflammatory effector mechanism provided by the innate immune system, resulting in both curative and undesirable side effects in mice and patients.

Citation Format: Daniel Hirschhorn, Lukas Kraehenbuehl, Sadna Budhu, Valeria Estrada Navarro, Levi Mark B Mangarin, Yacine Marouf, Jacob Ricca, Billel Gasmi, Olivier De Henau, Yanyun Li, Czrina Cortez, Hamadene Linda, Isabell Schulze, Cailian Liu, Katherine Panageas, Mario Lacuoture, Gabrielle A. Rizzuto, Mikala Egeblad, Jedd D. Wolchok, Taha Merghoub Merghoub. Neutrophil recruitment and activation promotes cutaneous adverse effects with T cell immunotherapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4052.
Abstract 412: Discovery and preclinical characterization of ISM9342A, a novel, potent, and orally bioavailable WRN inhibitor that suppresses MSI-H tumor growth
Authors: Zhao Pei , Zhu Wei , Ding Xiaoyu , Wan Jianfei , Chen Xiaojing , Zhang Man , Ding Xiao , Bavadekar Supriya , Rao Sujata , Ren Feng , Zhavoronkov Alex
Published: March 2024

Loss of function mutations in DNA mismatch repair genes can result in microsatellite instabilities (MSI) and high levels of MSI (MSI-H) contributes to tumorigenesis and is frequently observed in endometrial carcinoma, gastric cancer, and colorectal cancer. Although immune checkpoint inhibitors have been approved for the treatment of MSI-H tumors, there is still a large proportion of patients with MSI-H tumors who fail to respond to these therapies. Recently, two independent genome-wide loss of function screens have identified Werner syndrome helicase (WRN) as the top dependency for MSI-H cancer cell viability. WRN plays important roles in DNA repair and in the maintenance of genome integrity. Given that WRN deficiency selectively impairs the viability of MSI-H but not microsatellite stable cancer cells, WRN is a synthetic lethal target for MSI-H tumors.

ISM9342A is a novel and potent WRN inhibitor exhibiting single digit nanomolar IC50 values in both ATPase and helicase assays. ISM9342A suppressed the proliferation and increased double strand break markers in MSI-H cancer cells. Moreover, ISM9342A demonstrated promising in vivo anti-tumor efficacy in an MSI-H xenograft model along with tumor regression. ISM9342A demonstrated good drug-like properties, including excellent in vitro ADMET profiles and good in vivo exposure, including low clearance and optimal oral bioavailability across multiple preclinical species. Collectively, these findings highlight the potential of ISM9342A as a highly potent WRN inhibitor for the treatment of MSI-H tumors

Citation Format: Pei Zhao, Wei Zhu, Xiaoyu Ding, Jianfei Wan, Xiaojing Chen, Man Zhang, Xiao Ding, Supriya Bavadekar, Sujata Rao, Feng Ren, Alex Zhavoronkov. Discovery and preclinical characterization of ISM9342A, a novel, potent, and orally bioavailable WRN inhibitor that suppresses MSI-H tumor growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 412.
Abstract 4149: Real-time intravital trafficking of tumor infiltrating lymphocytes in breast cancer models
Authors: Ahn Soyeon , Akyildiz Kubra , Kim Hyunseok , Kim Pilhan
Published: March 2024

Cancer immunotherapy utilizing the immunoreactive efficiency of immune cells via adoptive cell therapy (ACT) has been a novel method of cancer treatment. In tumor microenvironment, immune cell reactivity of tumor-infiltrating lymphocytes (TILs) can facilitate cancer cell attack, which finally derives efficient suppression of tumor growth. However, the conventional evaluation for cancer immunotherapy has been generally performed by ex vivo methods, providing restricted information on lymphocyte motility and immune cell dynamics within the tumor microenvironment. In vivo data with the dynamic behavior of TILs in breast cancer can provide new insight to investigate novel targets of immune checkpoint inhibitors. In this research, longitudinal intravital imaging of motility trafficking of TILs in breast cancer animal models has been performed by utilizing intravital microscopy to unveil the immunoreactive dynamics of T cell activity in early stage. In vivo analysis of TIL motility within different breast cell lines, including 4T1 (mouse breast cancer cell), MDA-MB-231 (human triple-negative breast cancer cell), and MCF7 (human breast cancer cell), respectively, has been investigated for immune responses to cancer. We’ve monitored spatiotemporal dynamics of TIL over 11 days in breast cancer xenograft mouse model generated by tumor implantation into the dorsal skinfold imaging chamber and adoptive T cell transfer by blood circulation. In the results, the adoptive immunoreactivity of TIL has been differentiated by the timepoint of adoptive T cell transfer, distance proximity of T cells in tumors, and breast cancer types. Furthermore, anti-cancer effect coordinated with dendritic cells behaviors showed induced immune responses with accumulated dendritic cells with increased TIL count over time in breast cancer model treated with various cancer therapy such as immunotherapy, radiation therapy and anti-cancer drug (anti-PD-L1), which implied a relationship between programmed death-ligand 1 expression levels and TIL/dendritic cell motility. The result demonstrates that intravital TIL motility trafficking analysis in cancer model can be an invaluable assessment method to explain the detailed cellular/molecular mechanism of immune response to cancer involved with T lymphocytes, dendritic cells, and immune checkpoint inhibitors to accelerate the efficiency of cancer immunotherapy.

Citation Format: Soyeon Ahn, Kubra Akyildiz, Hyunseok Kim, Pilhan Kim. Real-time intravital trafficking of tumor infiltrating lymphocytes in breast cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4149.
Abstract 416: Development of substituted oxindole derivatives as a Ku-targeted DNA-PK inhibitors for cancer therapy
Authors: Chauhan Dineshsinha , Mendoza-Munoz Pamela L. , Kushwaha Narva Deshwar , Aruri Hariprasad , Turchi John J. , Gavande Navnath S.
Published: March 2024

DNA double strand breaks (DSBs) are the most cytotoxic type of DNA damage. DSB repair pathway deficiency, often observed in cancer cells, results in translocations and genetic mutations that contribute to genomic instability. The generation of DNA DSBs is the primary mechanism of numerous chemo- and radio-therapeutic strategies used to treat various cancers. Modulating DSB repair pathways can have a profound impact on the clinical efficacy of DNA damaging therapies. DNA-dependent protein kinase (DNA-PK), which is composed of a DNA-PK catalytic subunit (DNA-PKcs) and Ku80-Ku70 heterodimer, acts as the molecular sensor for DSB and plays a prime role in DSB repair through non-homologous end joining (NHEJ). DNA-PK inhibitors become an attractive therapeutic target for cancer in combination with DSB-inducing radiotherapy and chemotherapy. There are at least 6-7 DNA-PK inhibitors in the preclinical and clinical stages which exhibit potential as treatment for various cancers. However, we have taken a unique and innovative approach to inhibiting DNA-PK via blocking the Ku70/80 heterodimer interaction with DNA, an essential step in DNA-PK activation and phosphorylation activity. Exploiting this unique mechanism of kinase activation, we have expanded our structure-activity relationships of pyrrolone derivatives. Modified synthetic schemes have been developed to allow a series of modifications to the X80 core structure. We have prepared furan, thiophene and pyrrole derivatives that enabled the identification of pharmacophores that impact in vitro potency and cellular off-target toxicity. Towards addressing cellular uptake and bioavailability, we identified substituted oxindole derivatives as potent Ku and DNA-PK inhibitors. These oxindole derivatives exhibited a better cellular uptake while retaining potent Ku inhibitory activity. Our data demonstrate that the cellular effects observed are a function of Ku inhibition and that this novel class of DNA-PK inhibitors can be further developed as anti-cancer therapeutics that can be used as an adjuvant to, or concomitant with radiotherapy and other cancer therapies that induce DNA damage.

Citation Format: Dineshsinha Chauhan, Pamela L. Mendoza-Munoz, Narva Deshwar Kushwaha, Hariprasad Aruri, John J. Turchi, Navnath S. Gavande. Development of substituted oxindole derivatives as a Ku-targeted DNA-PK inhibitors for cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 416.
Abstract 4209: Unraveling the effects of the microenvironment on glioblastoma multiforme invasiveness using a xeno-free 3D hydrogel platform
Authors: Díaz Alejandra I. Ferrer , Huang John
Published: March 2024

Glioblastoma multiforme (GBM) is a grade IV astrocytoma and the most common type of adult brain malignancy. The overall survival of patients diagnosed with GBM is less than 5 years. Therefore, it is imperative to understand the mechanisms contributing to GBM progression, invasiveness, and survival. This study aimed to evaluate the effect of the extracellular matrix (ECM) on GBM cell invasion by performing the traditional invasion assay as well as novel  in vitro invasion assay strategies. A significant challenge with in vitro cell invasion assays is the use of animal-based ECM: the components of animal-based ECM are not characterized; the batch-to-batch variability of animal-based ECM can influence experimental findings and affect potential clinical applications; and the temperature-sensitive operation protocols make the use of animal-based ECM time-consuming and difficult for automated high-throughput assays. These challenges can be circumvented using VitroGel®, a synthetic xeno-free, bio-functional hydrogel resembling the physiological ECM with tunable biophysical and biochemical properties. In this study, we harnessed the properties of the synthetic xeno-free hydrogel system to examine how different mechanical strengths and functional ligands as well as cytokines and serum within the hydrogel matrices or in the outer well, affect GBM cell invasion. The results indicated that adjusting the mechanical strength of the ECM system affects GBM cell invasion. We further showed that the bio-functional ligands within the hydrogel matrix, such as matrix metalloproteinases, RGD peptide, and others, stimulated cell invasion. This finding exemplifies the importance of using a well-characterized ECM system given that it is difficult to evaluate how specific ECM components contribute to cell invasion using the undefined animal-based ECM. Since the composition of the hydrogel system is chemically defined, we could further control the cytokine milieu within the matrix to understand how the ECM composition affects cell migration. To demonstrate this, we added the cytokine TGF-β1 to the hydrogel and examined GBM cell invasion. Indeed, we showed that adding TGF-β1 to the synthetic VitroGel enhanced GBM cell invasion, thus illustrating that incorporating factors inside the matrix is a powerful method to evaluate chemotaxis. Altogether, this study demonstrates the potency and flexibility of using a xeno-free hydrogel for a myriad of invasion assay applications.

Citation Format: Alejandra I. Ferrer Díaz, John Huang. Unraveling the effects of the microenvironment on glioblastoma multiforme invasiveness using a xeno-free 3D hydrogel platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4209.
Abstract 4217: An engineered breast tumor microenvironment model, with single-cell spatial resolution, to assess spatial dynamics of tumor evolution
Authors: Helms Haylie R. , Oyama Kody A. , Davies Alexander E. , Langer Ellen M. , Bertassoni Luiz E.
Published: March 2024

Cellular heterogeneity is a prominent feature of the tumor microenvironment, and the organization of these cells has been linked to clinical outcomes such as disease progression and drug resistance. While retrospective analysis of patient tumors has produced a myriad of insights, samples are limited and highly complex making it challenging to validate causality. Here we present an engineered breast tumor microenvironment model, with single cell spatial resolution, to systematically identify which cell phenotypes and their spatial arrangements may be driving ductal carcinoma in situ disease progression. A microfluidic dispenser (Biopixlar, Fluicell) was optimized to enable the spatial patterning of single cells to replicate native histology. To demonstrate the high spatial precision of our method, we first replicated an annotated 2D section of a breast tumor biopsy region of interest (ROI) using MCF10A, MDA-MB-231, primary mammary fibroblasts, THP-1 derived macrophages, and primary mesenchymal stem cells. The XY coordinate of each cell was identified to create a print map matching the original biopsy. Deposited cells adhered to their intended target with an average print fidelity of 2.4 µm. Next, the stromal compartment of the ROI was altered to include phenotypes associated with tumor promoting microenvironments (i.e. cancer associated fibroblasts, M2 macrophages) and the core of the MCF10A ring filled with MDA-MB-231. Each deposited cell contained a fluorescent tag corresponding with its cell type to facilitate real time spatial tracking and annotation. The tumor microenvironments were live cell imaged for 24 hours at 5 minute intervals. MCF10A cells spread to form their junctions and create a cohesive ring, MDA-MB-231 cells proliferated and rapidly moved around within the confined space, and the cells of the stromal compartment spread to create a dense tissue like structure. The microenvironments were cultured for an additional 2-6 days, fixed, and stained for markers of proliferation, phenotype shifts, cell-cell junctions, and morphology. Unlocking the relative contributions of the specific cell types in ductal carcinoma in situ tumor microenvironment to the overall evolution of invasive breast cancer may hold the answer for many questions in early detection, treatment, and cancer avatar models.

Citation Format: Haylie R. Helms, Kody A. Oyama, Alexander E. Davies, Ellen M. Langer, Luiz E. Bertassoni. An engineered breast tumor microenvironment model, with single-cell spatial resolution, to assess spatial dynamics of tumor evolution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4217.
Abstract 4243: Revolutionizing cancer research, new drug screening approach with vascularized cancer organoid platform mimicking patient tumor microenvironment
Authors: Lee Mingyun , Yoon Yeo-Joon , Lee Yong-Soo , Rheey Jinguen
Published: March 2024

Patient-derived organoids (PDOs) are improving our understanding of cancer heterogeneity and personalized medicine. In particular, patients' intrinsic and acquired treatment resistance is being evaluated with PDOs, which has become an essential factor in developing new anticancer drugs and designing successful clinical trials. However, there are obstacles to cancer heterogeneity and patient-specific cancer therapy due to lack of understanding of tumoral diversity resulting from the tumor microenvironment (TME). Complex direct and indirect interactions between various types of TME cells and the resulting tumoral diversity are challenges that must be addressed for customized cancer therapy. Standard cancer therapy targets tumor cells without considering possible damage on the tumor microenvironment that could impair therapy response. Therefore, the construction and analysis of a platform for co-culturing cancer organoids with other cell types that make up the TME over a long period of time is necessary. We generated and performed characterization of blood vessel organoid (BVO). The BVO expressed endothelial marker CD31 and pericyte marker PDGFRβ. We attempted to co-culture with patient-derived lung cancer organoid (LCO) on Matrigel by dissociating the constructed BVO, and it was confirmed that BVO and LCO were interconnected after 10 days. This new platform was treated with Gefitinib and Poziotinib, and after 5 days of drug treatment, the IC50 value increased compared to LCO-only culture. Additionally, flow cytometry analysis confirmed that co-culturing with BVO during drug treatment resulted in a lower percentage of dead LCO cells compared to LCO-only culture. Image-based analysis also verified that co-culturing with blood vessels enhances the viability of LCOs when treated with drugs. Taken together, the co-culture of cancer organoids and BVOs present a platform that closely mimics the in vivo TME compared to the existing cancer organoid culture method. This innovative platform demonstrates higher drug resistance than existing approaches, offering a novel method for drug screening.

Citation Format: Mingyun Lee, Yeo-Joon Yoon, Yong-Soo Lee, Jinguen Rheey. Revolutionizing cancer research, new drug screening approach with vascularized cancer organoid platform mimicking patient tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4243.
Abstract 4256: Autologous organoids and T cell co-cultures as a powerful personalized platform for immunotherapy development
Authors: Beaurivage Claudia , Sridharan BanuPriya , Mucuk Sumeyra , Nadwodny Kimberly , Poore Derek , Schepers Anna , Pourfarzad Farzin , Boj Sylvia F.
Published: March 2024

Recent advances in cancer immunotherapy have had a positive impact on the life expectancy of patients for an extensive range of clinical indications. With new treatment strategies and druggable targets being identified at an increasing pace, the number of patients eligible for cancer immunotherapy is expected to expand steadily. However, promising therapeutic developments face hurdles in translating preclinical findings into therapy since conventional 2D cancer models hold low clinical predictive value. We developed an innovative alternative, building on the discovery that adult stem cells proliferate and organize into three-dimensional organotypic structures when they are embedded into extracellular matrix. Patient-derived organoids are generated from normal and malignant tissues and stored as high-quality biobanks that yield highly reproducible results. HUB Organoids® recapitulate complex characteristics of the parental tissue, including molecular heterogeneity, as well as morphological and functional traits. Since cancer progression and response to immunotherapy are governed by immune cell interactions in the tumor microenvironment, we developed an assay in which colorectal (CRC) and non-small cell lung cancer (NSCLC) tumor organoids are co-cultured with paired tumor infiltrating lymphocytes (TIL) that are simultaneously expanded as a source of tumor reactive cells. Paired resources allow for the screening of immune-modulatory therapies under physiologic conditions, not depending on peptide-pulsing and alloreactivity. We quantify tumor organoid killing and TILs reactivity by combining imaging-based analysis of apoptotic cells with flow cytometry to measure cytokine release by cytotoxic TILs. Here, we show that our system is robust and reproducible with an establishment rate of 75%, allowing for expansion of TILs that preserve T cell receptor repertoires. First line expansion of both PDO and TIL components can be used to effectively build coculture models and probe the tumor and immune components, respectively. Our system offers a powerful tool for the development and validation of cancer immunotherapy and can help to stratify cancer patients for susceptibility to various types of immunotherapies. We certify that the research use of each of the HBS marked above was conducted according to the expectations of each institution.

Citation Format: Claudia Beaurivage, BanuPriya Sridharan, Sumeyra Mucuk, Kimberly Nadwodny, Derek Poore, Anna Schepers, Farzin Pourfarzad, Sylvia F. Boj. Autologous organoids and T cell co-cultures as a powerful personalized platform for immunotherapy development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4256.
Abstract 4299: A lineage-specific role of oncogenic protein kinase Cι in lung adenocarcinoma
Authors: Nguyen Duy T. , Yin Ning , Weems Capella R. , Jamieson Lee , Meneses Kayleah , Liu Yi , Murray Nicole R. , Fields Alan P.
Published: March 2024

Lung adenocarcinoma (LUAD), the most prevalent subtype of lung cancer, can arise from two different cell populations: alveolar type 2 (AT2) cells and bronchiolar club cells. By utilizing genomic data from the cancer genome atlas program, human LUAD cell lines, and the well-characterized LSL-KrasG12D/Trp53-/- (KP) mouse model, we demonstrated that tumors arising from club cells are much more aggressive and follow a different trajectory of tumorigenesis when compared to those arising from AT2 cells. Intriguingly, our data strongly suggest that expression and signaling activity of protein kinase C iota (PKCι) can profoundly affect the cell of origin and oncogenic signaling pathways employed by resultant tumors. Specifically, KP-mediated transformation of club cells appears to be dependent on PKCι-ELF3-NOTCH3 and PKCι-YAP1 signaling axes, while AT2 cell malignancy is dependent on the PKCι-independent WNT signaling. In addition, club-cell-origin tumors exhibit an enrichment of cancer stem cells and increased infiltration of immunosuppressive myeloid cells in comparison to AT2-cell-origin tumors. This results in accelerated progression and increased likelihood of metastasis by LUAD tumors that originate from club cells. Taken together, our results indicate that PKCι expression and signaling activity can profoundly influence the cells of origin, tumor trajectories, and therapeutic vulnerabilities of LUAD tumors.

Citation Format: Duy T. Nguyen, Ning Yin, Capella R. Weems, Lee Jamieson, Kayleah Meneses, Yi Liu, Nicole R. Murray, Alan P. Fields. A lineage-specific role of oncogenic protein kinase Cι in lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4299.
Abstract 4319: HSF1 inhibition induces pancreatic ductal adenocarcinoma autophagy through JNK
Authors: Ghai Shruti , Young Alex , Su Kuo-Hui
Published: March 2024

Background: Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related mortality, with a 5-year survival rate of 12%. Chemoresistance due to autophagy, a natural process of proteotoxic stress response, is the most common chemotherapy challenge for pancreatic cancer. Autophagy, which maintains cellular homeostasis by removing damaged or unnecessary proteins and organelles, is a self-degradation process regulated by the mammalian target of rapamycin complex (mTORC1). Excessive levels of autophagy can be detrimental and lead to cell death. Nevertheless, this dual function of autophagy in regulating pancreatic cancer remains poorly understood. It has been reported that heat shock factor 1 (HSF1), a critical pro-oncogenic transcription factor in the proteotoxic stress response, inhibits c-Jun N-terminal kinase 1/2 (JNK1/2) signaling pathway to maintain mTORC1 activity and control cell size. HSF1 is highly expressed in pancreatic tumors, and inhibition of HSF1 via small molecules enhances the chemotherapy drug effect on PDAC programmed cell death. However, the PDAC autophagy response in HSF1 inhibition is currently not fully understood. Objective: The objective of this study is to investigate the molecular mechanism of HSF1 inhibition in PDAC autophagy.

Methods and Results: In human PDAC cells, Western blotting analysis revealed that HSF1 inhibition via small molecular including CCT361814/NXP800, an HSF1 inhibitor in phase I clinical trials, increased autophagy marker microtubule-associated protein 1A/1B-light chain 3 (LC3) lipidation and decreased expression of phosphorylation of HSF1 at Ser326 and total HSF1 protein, conversely using HSF1 overexpression model reversed this effect. Inhibition of autophagy via 3-methyladenine reversed HSF1 inhibition-induced autophagy. Results from transmission electron microscopy and GFP-LC3 reporter revealed that HSF1 inhibition induced autophagosome formation and accumulation. Furthermore, HSF1 inhibition induced phosphorylation of JNK1/2 at Thr183/Tyr185 and decreased mTORC1 activity, while knockdown JNK1/2 diminished HSF1 inhibition-induced LC3 lipidation. The combination of chemotherapy drugs with HSF1 inhibitors decreased PDAC cell viability. Additionally, blocking autophagy increased HSF1 inhibition-induced apoptosis.

Conclusions: In conclusion, JNK1/2 is involved in HSF1 inhibition-induced PDAC autophagy, targeting autophagy could unveil a novel treatment strategy for pancreatic cancer through targeted HSF1 inhibition.

Citation Format: Shruti Ghai, Alex Young, Kuo-Hui Su. HSF1 inhibition induces pancreatic ductal adenocarcinoma autophagy through JNK [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4319.
Abstract 432: The noncanonical mechanism of metabolic enzyme LDHA in cancer progression
Authors: Liu Juan , Hu Wenwei , Feng Zhaohui
Published: March 2024

Metabolic reprogramming is a hallmark of cancer cells and a key contributor to cancer progression, which is a promising target for cancer therapies. The enhanced glycolysis, also known as the Warburg effect, represents the most widely recognized metabolic alteration in cancer, wherein the majority of cancer cells undergoes reprogramming to heavily rely on glycolysis for their accelerated growth and proliferation. The glycolytic enzyme lactate dehydrogenase A (LDHA) catalyzes the conversion of pyruvate to lactate in the final stage of glycolysis. LDHA is frequently overexpressed in cancers, which plays a critical role in promoting glycolysis and cancer progression. To deepen our understanding of the oncogenic mechanism of LDHA, we screened for LDHA-interacting proteins in human breast cancer cells by liquid chromatography mass spectrometry (LC/MS) analysis. Through this strategy, small GTPase Rac1 was identified as an LDHA-interacting protein. LDHA interacted with the active form of Rac1, Rac1-GTP, and impaired the interaction of Rac1-GTP with its negative regulators, GTPase-activating proteins, leading to Rac1 activation independently of the glycolytic enzyme activity of LDHA. In addition, LDHA overexpression was significantly associated with increased Rac1 activity in clinical breast cancer specimens. Inhibiting Rac1 significantly attenuated the oncogenic effect of LDHA. Combining small-molecule inhibitors targeting LDHA enzyme activity and Rac1 activity displayed a synergistic inhibitory effect on breast cancers with LDHA overexpression in mouse models. Thus, our results revealed a novel and critical noncanonical mechanism of LDHA in promoting cancer progression through its direct interaction and activation of Rac1. Given that LDHA is frequently overexpressed in cancer, LDHA overexpression constitutes an important mechanism contributing to aberrant Rac1 activation in cancer. Importantly, our findings also suggest that pharmacologically targeting LDHA enzyme activity and Rac1 activity simultaneously is a promising strategy to treat breast cancers with LDHA overexpression.

Citation Format: Juan Liu, Wenwei Hu, Zhaohui Feng. The noncanonical mechanism of metabolic enzyme LDHA in cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 432.