bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 6607: Serine depletion promotes antitumor immunity throughmitochondrial DNA-mediated cGAS/STING1 activation
Authors: Saha Suchandrima , Ghosh Monisankar , Jinyu Li , Wen Asher , Galluzzi Lorenzo , Martinez Luis , Montrose David C.
Published: March 2024

Serine is critical for supporting cancer metabolism, and as such, depriving malignant cells of this non-essential amino acid exerts anticancer effects, in large part, through disrupting their metabolic pathways. However, the impact of these metabolic defects on tumor-targeting immunity remains poorly understood. Here, we show that restricting endogenous and exogenous serine in colorectal cancer (CRC) cells results in mitochondrial dysfunction coupled to cytosolic mitochondrial DNA accumulation and cGAS/STING1-dependent type I interferon secretion. Serine-deprived tumors have suppressed growth, accompanied by type I interferon signaling and tumor infiltration by immune effector cells. Blocking cGAS/STING1 signaling in tumor cells limits the immunostimulatory and anticancer effects of serine deprivation. Moreover, serine-depleted tumors exhibit increased sensitivity to a programmed cell death 1 blocker. Lastly, transcriptomic data from human CRCs suggest that malignant lesions with reduced serine abundance have higher immune infiltration. Taken together, our findings reveal a novel role for serine as a gatekeeper of mitochondrial integrity and hence a suppressor of anticancerimmunity.

Citation Format: Suchandrima Saha, Monisankar Ghosh, Li Jinyu, Asher Wen, Lorenzo Galluzzi, Luis Martinez, David C. Montrose. Serine depletion promotes antitumor immunity throughmitochondrial DNA-mediated cGAS/STING1 activation [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 6607.
Abstract 6626: Functional and molecular interrogation of a high-plasticity cell state in lung cancer
Authors: Chan Jason Earl , Pan Chun-Hao , Sussman Carleigh , Styers Hannah , Brown Emma , Hartmann Griffin , Meškauskaitė Brigita , Blum Melissa , Ding Selena , Torborg Stefan , Li Zhuxuan , Joost Simon , Rivas-Hernandez Eliud , Norman Thomas , Chaligne Ronan , Yan Yan , Tammela Tuomas
Published: March 2024

Despite recent advancements in lung adenocarcinoma (LUAD) treatment, mortality remains high. Thus, a need exists for novel therapeutic concepts to enhance treatment efficacy and improve patient survival. Cancer cell plasticity, the capacity for cancer cells to differentiate and adapt to cell-extrinsic pressures, drives LUAD progression and enables treatment resistance. We discovered a molecularly distinct "high-plasticity cell state" (HPCS), which emerges during the initial stages of tumor development and is maintained in established tumors, comprising 10-15% of the cancer cell pool. We hypothesized that the HPCS is critical for tumor progression and drug resistance. To functionally interrogate this cell state, we engineered a novel genetic system that enables both in situ ablation (via a suicide gene) and longitudinal lineage tracing (via secreted luciferases) of the HPCS in an autochthonous genetically engineered mouse LUAD model. Lineage-tracing revealed the HPCS harbors high differentiation potential (plasticity) and growth potential in situ. Strikingly, ablation of the HPCS led to robust tumor regression and growth suppression. Motivated by these findings, we sought to identify molecular drivers of the HPCS using an in vivo multiplexed gene perturbation approach coupled to single-cell RNA sequencing. This effort led to the identification of central transcriptional plasticity drivers. This study motivates the therapeutic targeting of the HPCS in lung cancer and uncovers candidate targets.

Citation Format: Jason Earl Chan, Chun-Hao Pan, Carleigh Sussman, Hannah Styers, Emma Brown, Griffin Hartmann, Brigita Meškauskaitė, Melissa Blum, Selena Ding, Stefan Torborg, Zhuxuan Li, Simon Joost, Eliud Rivas-Hernandez, Thomas Norman, Ronan Chaligne, Yan Yan, Tuomas Tammela. Functional and molecular interrogation of a high-plasticity cell state in lung cancer [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 6626.
Abstract 6632: Adipocyte death drives dormant breast cancer cell reactivation
Authors: Yuan Xiaoyu , Ren Qihao , Stewart Sheila A.
Published: March 2024

Despite significant responses to initial treatments, upwards of 30% of breast cancer patients will experience a recurrence of their disease. Unfortunately, there are few clinical features that predict which patients will recur, relegating patients and their doctors to a wait-and-see approach where they must remain vigilant. Recent studies have reported that the presence of disseminated tumor cells (DTCs) in the bone marrow of early-stage breast cancer patients predicts a higher chance of recurrence and that obese patients experience 35%-40% higher rates of recurrence than lean patients. Interestingly, in addition to increased adipocyte size, obese patients experience higher rates of adipocyte apoptosis, macrophage recruitment to adipocyte tissue, and increased inflammation, shown as the formation of crown-like structures (CLSs). Given the rising prevalence of obesity, the need for mechanistic studies to elucidate its contribution to breast cancer dormancy and recurrence is urgent. To investigate how microenvironmental changes associated with obesity affect breast cancer dormancy, we utilized a well-established syngeneic mouse model of ER+ breast cancer dormancy (D2.0R). We found that D2.0R cells remained dormant in the visceral fat of wildtype mice but were reactivated upon adipocyte death due to obesity or genetic manipulation, and this reactivation required the recruitment of macrophages. To understand why macrophages were recruited to the adipose tissue and how they led to dormant tumor cell reactivation, we profiled the microenvironmental changes in visceral fat using single-cell RNA-sequencing and found that the infiltrating macrophages exhibited unique pro-inflammatory and lipid regulatory phenotypes. Further investigation revealed that macrophages activated the integrin-focal adhesion kinase (FAK) pathway in dormant D2.0R cells and the inhibition of integrin and FAK inhibited this activation. Given tumor cells can metastasize to visceral fat depots in breast cancer patients, our findings provide an important model to determine what drives dormant tumor cell growth in adipose tissue. Our study provides novel insights into how tumor microenvironment (TME) impacts breast cancer dormancy and also highlights the importance of adipose tissue as a unique reservoir that potentiates cancer relapse.

Citation Format: Xiaoyu Yuan, Qihao Ren, Sheila A. Stewart. Adipocyte death drives dormant breast cancer cell reactivation [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 6632.
Abstract 6640: Zap! Irreversible electroporation in pancreatic cancer cells induces proinflammatory cell death and improves progression free survival
Authors: Powar Manali , Imran Khan Mohammad , Allen Irving C. , Davalos Rafael V. , Salamah Zaid , Aycock Kenneth , Brock Rebecca M. , Coutermarsh-Ott Sheryl , Orr Katie
Published: March 2024

Pancreatic cancer is the third leading cause of cancer-related death due to its late diagnosis, few treatment options, and extremely low survival rates due to its immunosuppressive microenvironment. Irreversible electroporation (IRE),is a tumor non-thermal ablation technique that applies high-voltage electrical pulses to permeabilize the cell membrane that is irreversible and leads to necrotic cell death. IRE has had strong success in clinical trials nevertheless, little is known about the effect of IRE beyond the initiation of cell death in the tumor tissue. We hypothesize that IRE can not only induce cell death by membrane disruption to facilitate a proinflammatory microenvironment but also causes death via cell cycle arrest. We utilized in-vitro, and immunocompetent in-vivo murine models to investigate changes to pancreatic cancer and the tumor microenvironment. Our findings show that treating the cells with an increasing voltage of IRE induces more cell death. We observed cell cycle arrest in the G1 phase which may have been caused by DNA damage. There was upregulation of DNA damage repair machinery in the treated samples. Our histopathology data suggests increased necrosis on the tumor treated with IRE, as also PCR array analysis showed more proinflammatory cell death caused by pyroptosis. Finally, we demonstrated a reduction in the tumor size and a better survival rate aftertreatment. Our data suggest that Irreversible electroporation has a promising future in inducing proinflammatory type of cell death in the tumor and benefits increased patient survival. More investigation is needed to define ideal parameters for the electrical pulses and device development for tumor ablation in larger animals like porcine models.

Citation Format: Manali Powar, Khan Mohammad Imran, Irving C. Allen, Rafael V. Davalos, Zaid Salamah, Kenneth Aycock, Rebecca M. Brock, Sheryl Coutermarsh-Ott, Katie Orr. Zap! Irreversible electroporation in pancreatic cancer cells induces proinflammatory cell death and improves progression free survival [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 6640.
Abstract 6678: Microbial regulation of anti-tumor immunity in colorectal cancer
Authors: Chung Charlie , Ozcelik Elif , Habel Jill , Zhang Jialin , Qin Yihan , Garcia Libia , Merrill Joseph , Chung Taemoon , Lyons Scott , Shen Zeli , Fox James G. , Westcott Peter , Beyaz Semir
Published: March 2024

Colorectal cancer (CRC) is the 3rd leading site of cancers and cause of cancer cell death. Although Immunotherapies revolutionized cancer therapy, the majority of CRC patients, particularly with metastatic disease, do not respond to the treatments. This necessitates a better mechanistic understanding of the tumor-immune cell interactions in the context of CRC. Microbiome influences multiple biological aspects of the host including immune responses against cancers. Here, we show that the gut microbiome influences cancer MHC-I and -II expression levels and restricts tumor progression and metastasis, resulting in longer survival in 3 different CRC models and two different mouse strains. We found that the anti-tumor effects are dependent on T cells and B cells. Interestingly, depletion of B cell negated anti-metastatic effects of gut microbiome. Mechanistically, MHC-II expression in cancer cells mediates the anti-tumor effects of the microbiome. MHC-II upregulation on human CRC organoids enhances cancer-immune cell interactions and associated apoptosis, demonstrating an anti-tumor role and significance of MHC-II in human CRC. Thus, gut microbes that enhance MHC-II antigen presentation promotes anti-tumor immunity and may be utilized to enhance efficacy of immunotherapy in metastatic CRC.

Citation Format: Charlie Chung, Elif Ozcelik, Jill Habel, Jialin Zhang, Yihan Qin, Libia Garcia, Joseph Merrill, Taemoon Chung, Scott Lyons, Zeli Shen, James G. Fox, Peter Westcott, Semir Beyaz. Microbial regulation of anti-tumor immunity in colorectal cancer [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 6678.
Abstract 6689: Modulation of MAITs by the tumor microbiome in anti-PD1 treated cancers
Authors: Birla Pakhi , Yang Lansaol , Sears Cynthia , Shaikh Fyza , Pardoll Drew , Housseau Franck
Published: March 2024

Mucosal associated invariant T (MAIT) cells are innate like T-cells that recognize non-peptide metabolite antigens presented on monomorphic MHC related-1 (MR1) making them an attractive off the shelf tool for cancer immunotherapy. In this study, we investigate the function of MAITs in the tumor microenvironment of neoadjuvant anti-PD1 treated lung cancer patients (NCT02259621)). Paired single cell RNA/TCR sequencing analysis revealed an oligoclonal expansion of MAITs comprising of canonical TRAV1-2+ and non-canonical MAITs TRAV1-2-. TCR capture from canonical MAIT clonotypes confirmed their in vitro recognition of 5-OP-RU, bacteria derived riboflavin derivative as well as MR1 dependent recognition of live bacteria present in the tumor. However, the nature of antigens recognized by non-canonical MAITs remains poorly understood. On mining transcriptional profiles of MAITs, we observed that canonical MAITs were characterized by high clonal amplification whereas the non-canonical clonotypes expressed a strong activation/exhaustion gene signature. This suggests that both these MAIT populations recognize different types of antigens, differentially activate, and respond to immune checkpoint blockade (ICB), the non-canonical MAITs being highly dysfunctional. Using bacterial 16S RNA amplicon and metagenomics sequencing, we seek to identify microbial and metabolomics signatures associated with MAIT activation and response to ICB. We identified MAITs to express a cytotoxic signature making them a potential target for cancer immunotherapy. Our findings will provide further insights into the nature of ligands recognized by MAITs and the mechanisms associated with MR1 dependent recognition and tumor killing. Investigating the role of unconventional T-cells in response to ICB has the potential to reveal new tumor-associated antigens which could open avenues into innovative combination immunotherapies.

Citation Format: Pakhi Birla, Lansaol Yang, Cynthia Sears, Fyza Shaikh, Drew Pardoll, Franck Housseau. Modulation of MAITs by the tumor microbiome in anti-PD1 treated cancers [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 6689.
Abstract 6747: Engineering M13 filamentous phages to target dendritic cells and elicit anti-tumor immunity
Authors: Au-Yeung Yee Man Betty , Zeng Zheng , Huang Jiandong
Published: March 2024

Filamentous phage is a safe and effective vaccine vector that can elicit robust immune responses by activating Toll-like receptor pathways. However, engineering neoantigen-displaying phages for cancer vaccines using phage display technology has been challenging and yielded inconsistent results.

We developed a dendritic cell (DC)-targeting cancer vaccine platform with M13 filamentous phages using the phage display technology. The engineered phages express DC-targeting peptides (SLS) on p3 sites and spy-catcher proteins on p8 positions, allowing neoantigens and proteins of interest to be linked to the phage vector. We named our platform SCP (SLS-spy catcher phage). Imaging and western blot showed that spy-tagged proteins can be easily attached to SCP by simple mixing. Further studies demonstrated that targeting DCs can enhance antigen presentation and anti-cancer immunity.

We tested SCP in MB49 and B16 mouse models and the serum, spleen and tumor tissues were isolated for further investigation of immune response upon treatment. We found that SCP effectively suppressed tumor growth by inducing systemic anti-tumor humoral and cell-mediated immunity. SCP also showed efficacy in late-stage tumor models. SCP treatment triggered particularly robust local anti-tumor response. Histological and flow cytometry analysis revealed increased infiltration of innate and adaptive immune cells, reduced PDL1 expression, and restricted neovascularization in the tumor microenvironment after intratumoral administration of SCP.

Our study demonstrated that SCP can induce multifactorial modifications in the tumor microenvironment to impede tumor growth. SCP overcomes the limitations of traditional phage display technology, enabling a wide variety of peptides and proteins to be loaded onto the phage vectors. SCP is also cost-effective and scalable as phage production and purification processes are relatively mature. We propose that SCP can serve as a universal platform for cancer immunotherapy, and may offer novel treatment options for patients.

Citation Format: Yee Man Betty Au-Yeung, Zheng Zeng, Jiandong Huang. Engineering M13 filamentous phages to target dendritic cells and elicit anti-tumor immunity [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 6747.
Abstract 6754: A microneedle array patch chemo-immunotherapy for cutaneous squamous cell carcinoma
Authors: Yang Yufan , Zhang Haotong , Carey Cara D. , Zhang Jiying , Balmert Stephen C. , Korkmaz Emrullah , Falo Louis D.
Published: March 2024

Cutaneous squamous cell carcinoma (cSCC) is the second most common human malignancy worldwide. Current therapies, including surgical excision, are associated with significant morbidities and considerable expense. Multiple efforts are now underway to develop novel therapies that are effective, durable, safe, cost-effective, and patient-friendly. Here, we report ongoing efforts to develop a localized dissolvable microneedle array patch (MAP) based therapy for cSCC. Our approach is based on the hypothesis that the delivery of an immunogenic cell death (ICD) inducing chemotherapeutic agent to the tumor microenvironment (TME) of accessible cSCCs could kill tumor cells as a source of antigen and induce a proinflammatory TME to generate a potent patient-specific anti-tumor immune response. Specifically, we evaluated MAP therapy using a UV-induced preclinical cSCC mouse model. We applied MAPs delivering the potent ICD-inducing chemotherapeutic agent, doxorubicin (DOX) to UV-induced tumors. MAPs efficiently delivered DOX to the tumor microenvironment. Compared to traditional needle injection, MAP delivery resulted in sustained high levels of DOX in the TME with minimally systemic exposure. Cell death was evident in MAP-DOX-treated tumors, and treatment resulted in tumor regression, increased survival, and long-term immune protection. Further, we found that tumor regression was associated with an early proinflammatory neutrophilic infiltrate. Taken together, our results suggest that MAP delivery of doxorubicin may be a promising approach to cSCC treatment. and that proinflammatory neutrophils are likely an important component of the early infiltrate that leads to tumor regression.

Citation Format: Yufan Yang, Haotong Zhang, Cara D. Carey, Jiying Zhang, Stephen C. Balmert, Emrullah Korkmaz, Louis D. Falo. A microneedle array patch chemo-immunotherapy for cutaneous squamous cell carcinoma [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 6754.
Abstract 6782: 3D-EXpress - an ex vivo platform using viably cryopreserved tumoroids for rapid assessment of targeted therapeutic outcomes
Authors: Garrido Vanessa , Ataya Michelle , Dhanushkodi Nisha R. , Currlin Seth , Humphrey Alliyah , Ehrhart Jared , Chakraborty Rikhia
Published: March 2024

Background: it has been a significant challenge to select, combine, and sequence the multiple FDA-approved IO therapies and pharmaceutical agents, highlighting the need to develop a precision oncology platform to explore novel combination treatments. 3D-EXpress is a unique ex vivo therapeutics testing platform using a biorepository of fresh patient tumoroids that were never dissociated, propagated, or reassembled to retain an intact microenvironment. Therefore, these specimens provide an excellent ex vivo platform to investigate the efficacy of therapeutics targeting the tumor microenvironment. Here, we employed the 3D-EXpress platform to compare the efficacy of different therapeutic modalities targeting tumor antigens and immune checkpoint ex vivo.

Methods: Tumoroids measuring 150 μm in size retaining tumor cell heterogeneity, tumor-resident immune cells, stromal components, and extracellular matrix interaction were prepared from human endometrial and colorectal tumors. Tumoroids were cryopreserved and were selected based on tumor antigen status. Samples were treated for 72 hours ex vivo with antibody-drug conjugates, chimeric antigen receptor (CAR)T cells, or bispecific antibodies alone and in combinations. Treatment-mediated changes in tumor cell killing and tumor immune microenvironment were investigated.

Results: 3D high throughput confocal imaging and Nilogen Oncosystem’s proprietary algorithm were used to detect and analyze treatment-induced tumor cell killing activity in tumoroids. The impact of ex vivo treatment by different modalities in combination with chemotherapeutic agents upon tumor resident immune cell populations was monitored by deep immune phenotyping and multiplex cytokine release assay. Based on the ex vivo responses tumors were assigned to treatment sensitive and resistant groups. Correlative analysis was performed and compared with detailed clinicopathologic data that is readily available for Biorepository tumors.

Conclusions: The 3D-EXpress platform using cryopreserved 3D tumoroids with intact tumor microenvironment is an effective tool for the pre-clinical assessment of rational drug combinations for treatment of solid tumors. Furthermore, the 3D-EXpress platform provides unique insight into the microenvironment of both treatment responsive and non-responsive tumors and can aid in the development of patient-centered therapeutic regimens.

Citation Format: Vanessa Garrido, Michelle Ataya, Nisha R. Dhanushkodi, Seth Currlin, Alliyah Humphrey, Jared Ehrhart, Rikhia Chakraborty. 3D-EXpress - an ex vivo platform using viably cryopreserved tumoroids for rapid assessment of targeted therapeutic outcomes [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 6782.
Abstract 6792: Investigating differential expression of Palladin isoform 3 in 2D and 3D pancreatic cancer cell cultures
Authors: Biswas Sonali , Bush Jason A.
Published: March 2024

Palladin (PALLD) is an actin-binding protein widely expressed in mammalian tissues that modulates cytoskeletal dynamics. Palladin is linked to the progression of breast, pancreatic, and renal cancers. There are at least 9 known isoforms of PALLD but isoforms 3 (iso3) and 4 (iso4) appear most significant in cancer cells and associated fibroblasts. Our goal is to understand iso3 in pancreatic cancer (PC) cell lines grown in various culture environments to shed light on the intricate interplay between culture conditions and gene regulation. Cell models were developed as 3D spheroids from hanging drops after optimizing culture conditions by utilizing a combination of inexpensive methylcellulose (MC) and rat tail collagen viscosity ranges across cell seeding densities. The quality of the developed spheroids was assessed using multiple parameters, like diameter, integrity, and circularity to determine ideal spheroid characteristics. Spheroids that formed at a lower MC viscosity range (350-550 mPa·s) led to peripheral loose cells and a higher viscosity range (7,000-10,000 mPa·s) resulted in elongated shapes. Moderate viscosity ranges (1,000-1,800 mPa·s and 3,500-5,600 mPa·s) consistently produced circular and compact spheroids. Optimal incubation times varied from 72 to 96 hr depending on the cell line. Invasion dynamics within collagen-MC gels revealed that PANC-1 had significantly higher invasion potential compared to BxPC-3 and a control cell line C2C12. RT-qPCR results show that PALLD iso3 was particularly overexpressed in the 3D culture environment of PANC-1, suggesting that elevated PALLD isoform 3 expression may be a characteristic of 3D culture, particularly in invasive PC types. Taken together, the study validates the importance of extracellular viscosity for influencing spheroid characteristics toward generating reproducible 3D spheroids. The investigation also highlights PALLD iso3 as a potentially valuable biomarker for aggressive forms of pancreatic cancer.

Citation Format: Sonali Biswas, Jason A. Bush. Investigating differential expression of Palladin isoform 3 in 2D and 3D pancreatic cancer cell cultures [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 6792.
Abstract 6833: Microenvironment-specific transcriptomic changes in osteosarcoma metastasis
Authors: Gunawardana-Zeigler Shimara , Peng Dan , Cahan Patrick , Loeb David
Published: March 2024

Osteosarcoma (OS) is the most common primary malignancy of bone in children and adolescents. While conventional chemotherapy has improved 5-year survival rates for localized disease to 70%, metastatic disease remains at 20-30%. Failure of modern treatment options to improve survival reflects the failure of agents that appear promising in preclinical models to demonstrate clinical efficacy in human patients. We hypothesize that this is because most preclinical testing is performed on tumors implanted subcutaneously in immune deficient mice. Our previous work has shown that tumors implanted subcutaneously do not metastasize, whereas genetically identical tumors implanted orthotopically (in the tibia) metastasize to lungs and bones. Thus, to better understand non-genetic drivers of metastasis, we implanted patient-derived xenografts (PDXs) either orthotopically or subcutaneously into NSG mice. Once tumors reached 1.5cm, tumors were extracted along with distant metastases and analyzed by single-cell RNA sequencing. Transcriptomic analysis reveals 1) that fragments of the same tumor implanted subcutaneously have a vastly different transcriptome than fragments implanted orthotopically, 2) the transcriptome of distant metastases is dramatically different from the transcriptome of the primary tumor, and 3) the gene expression profile of metastases is different in different metastatic sites. In all 3 of these circumstances, these differences reflect differences in differentiation status, signaling pathway activation, and immune cell infiltrate. Thus, we conclude that the environment in which a tumor grows significantly alters its gene expression and phenotype. Our study highlights the need for careful consideration of the tumor microenvironment when designing pre-clinical studies to ensure accurate representation of human osteosarcoma and may help to explain the dismal record of translating novel agents from preclinical studies into standard therapy.

Citation Format: Shimara Gunawardana-Zeigler, Dan Peng, Patrick Cahan, David Loeb. Microenvironment-specific transcriptomic changes in osteosarcoma metastasis [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 6833.
Abstract 6901: Paired colorectal and pancreatic cancer patient-derived tumor and organoids biobank
Authors: Wang Juiling , Ma Wen-Hui , Lo Yun-Chi , Hsieh Hsiao-Chun , Hsiao Li-Ju , Bau Yu-Pin , Yang Nai-Chieh , Tsai Shaw-Jenq , Shan Yan-Shen , Chen Tzu-Yu , Chen Yu-Ling , Chiang Pei-Ju , Chen Tzu-Ling , Chang Hsiu-Ping , Chin Hsian-Jean
Published: March 2024

Patient-derived xenograft (PDX) models constitute a crucial tool in precision cancer medicine owing to their high accuracy in predicting the response to therapeutic drugs among patients in clinical settings. Our center has established a biobank that collects more than 80 colorectal cancer and 25 pancreatic cancer PDX tissues, along with essential information about patients’ tumors and PDX models. However, cost-intensive and time-consuming limit the usage of PDX model in high throughput screening during drug development. To overcome this hurdle, we are generating a PDX-match paired organoid (PDXO) biobank by using emerging three-dimensional culture techniques. Before large-scaled expansion, the concordance between PDX tissues and PDXOs of partial specimens was evaluated firstly using short-tandem repeat (STR) analysis, immunohistochemistry (IHC) and H&E staining. Data of STR analysis performed by using AmpFLSTR Identifiler PLUS PCR Amplification Kit demonstrated that PDX tissues and PDXOs have identical DNA fingerprinting. IHC and H&E staining revealed PDX tissues and PDXOs have highly similar organ-specific markers expression (e.g., Cytokeratin 20, Caudal Type Homeobox 2, and Pan Cytokeratin) and histological morphology. Even after passing to at least five generations, passed PDXOs maintained high fidelity to their original state, as confirmed by whole-exome sequencing (WES) and STR analysis across passages. The WES analysis for passage 0 (P0) and passage 5 (P5) of PDXOs from different PDX tissues revealed there is more than 95% intersection between P0 and P5 PDXOs with the same missense mutation gene. The results of STR analysis showed that P0 and P5 PDXOs have identical STR profile. To evaluate the capability of PDXOs in clinical response prediction, several effective and ineffective drugs (e.g., oxapliplatin, 5-FU, gemcitabine) were tested. The results of drug testing indicated that PDXOs can be used to accurately predict the response to therapeutic drugs as PDX model but more efficient than PDX model. Therefore, PDXO biobank can serve as a valuable resource for high throughput in vitro drug screening prior in vivo efficacy confirmation using PDX models.

Citation Format: Juiling Wang, Wen-Hui Ma, Yun-Chi Lo, Hsiao-Chun Hsieh, Li-Ju Hsiao, Yu-Pin Bau, Nai-Chieh Yang, Shaw-Jenq Tsai, Yan-Shen Shan, Tzu-Yu Chen, Yu-Ling Chen, Pei-Ju Chiang, Tzu-Ling Chen, Hsiu-Ping Chang, Hsian-Jean Chin. Paired colorectal and pancreatic cancer patient-derived tumor and organoids biobank [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 6901.
Abstract 6958: CRIPTO-regulated extracellular vesicles mediate heterotypic cellular crosstalk in triple negative breast cancers
Authors: Freeman David W. , Gates Brooke L. , Spendlove Mauri D. , Spike Benjamin T.
Published: March 2024

Tumor progression involves dynamic interaction between various cell types within the tumor microenvironment. Fibroblasts, which normally participate in wound healing, reciprocally communicate with breast cancer cells to promote tumor cell plasticity and heterogeneity. Gaining insights into the molecular mechanisms underlying this cell-to-cell communication, could unlock novel therapeutic avenues for inhibiting cellular plasticity, breast cancer progression and metastasis. The small GPI-anchored adaptor protein CRIPTO is a key player in this context though important molecular details remain to be elucidated. CRIPTO orchestrates TGF-β pathway signaling as well as growth factor-like signaling pathways that activate c-Src/MEK/AKT, in an autocrine and paracrine manner. CRIPTO is expressed during mammary development, wound healing, and breast cancer but is largely undetectable in homeostatic tissue, making it a promising therapeutic target. Our previous studies have demonstrated that the activity of CRIPTO is contingent upon cellular stress, with pronounced influence within pro-fibrotic, hypoxic domains of tumors. Importantly, we have shown that inhibition of CRIPTO using the soluble recombinant protein antagonist A4Fc effectively impedes the progression of triple negative breast cancer (TNBC) in murine xenograft models. Building upon these findings, we have been dissecting CRIPTO’s role in coordinating fibroblast activation and cell-state reprogramming in TNBC. We find that inhibition of CRIPTO with A4Fc suppresses cancer associated fibroblast (CAF) activation and collagen remodeling in vivo. Further, by modeling tumor cell:fibroblast crosstalk in vitro, we have demonstrated mechanistically that CRIPTO expression in tumor cells mediates subsequent extracellular vesicle (EV) uptake by fibroblasts, as well as fibroblast SMAD pathway activation and priming for reciprocal signaling back to tumor cells to promote transcriptional reprogramming and cellular invasion.The significance of these findings lies in their elucidation of key EV control mechanisms that could be exploited to intervene in essential tumor cell:fibroblast crosstalk or to enhance targeting of therapeutic moieties based on EV architecture and function in cancer and/or normative regenerative processes.

Citation Format: David W. Freeman, Brooke L. Gates, Mauri D. Spendlove, Benjamin T. Spike. CRIPTO-regulated extracellular vesicles mediate heterotypic cellular crosstalk in triple negative breast cancers [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 6958.
Abstract 6959: Acetylcholine potentiates invasion and migration of human pancreatic cancer cells under hypoxia through α7 nAChR-mediated increases in HIF-1α expression
Authors: Cho Yunmi , Oh Eun-Taex , Kim Ha Gyeong , Park Heon Joo
Published: March 2024

The most significant nerve-related problem in clinical pancreatic cancer management is perineural invasion (PNI), characterized as the neoplastic invasion of cancer cells into or surrounding the nerves. It is a characteristic feature of pancreatic ductal adenocarcinoma (PDAC) associated with a poor prognosis, tumor recurrence, and emergent pain. However, why PDAC is associated with a higher incidence of PNI remains unclear. HIF-1 (hypoxia-inducible factor-1) regulates the expression of ~1000 genes involved in angiogenesis, metastasis, tumor growth, chemoresistance and radioresistance, underscoring the growing interest in targeting HIF-1 for cancer control. In the present study, we investigated the molecular mechanisms underlying neurotransmitter acetylcholine (Ach)-potentiated HIF-1α expression and subsequent increase in invasion and migration of human pancreatic cancer cells in hypoxia (2% O2). The expression of various acetylcholine receptors in six types of pancreatic cancer cell lines (MIA-PaCa-2, PANC-1, HPAF-II, Capan-1, AsPC-1, and BxPC-3 cells) was observed using qPCR, and α7 nAChRs was observed to be expressed in all pancreatic cancer cells. Therefore, we chose MIA-PaCa-2 cells, expressing high levels of α7 nAChRs, and HPAF-II cells, expressing low levels of α7 nAChRs, for loss- and gain-of-function studies, respectively. In vitro assays showed that, under hypoxic conditions, Ach caused a concentration-dependent increase in α7 nAChRs-mediated HIF-1α expression, enhancing expression of HIF-1α target genes, and promoting invasion and migration of human pancreatic cancer cells. We further found that Ach increased HIF-1α protein stability in pancreatic cancer cells under hypoxic conditions. This effect was mediated by YAP signaling, as evidenced by the fact that Ach-induced increases in HIF-1α protein stability were blocked by siRNA-mediated knockdown of YAP. Consistent with these findings, an investigation of the relationship between α7 nAChRs and clinicopathological features in pancreatic cancer patients using publicly available datasets showed that high levels of α7 nAChRs are correlated with a poorer prognosis in pancreatic cancer patients. Collectively, these findings identify novel mechanisms by which Ach potentiates invasion and migration of pancreatic cancer cells and provide further evidence that HIF-1α is a potential anticancer target in Ach-associated pancreatic cancer.

Citation Format: Yunmi Cho, Eun-Taex Oh, Ha Gyeong Kim, Heon Joo Park. Acetylcholine potentiates invasion and migration of human pancreatic cancer cells under hypoxia through α7 nAChR-mediated increases in HIF-1α expression [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 6959.
Abstract 6965: Characterizing the proteome landscape of extracellular vesicles from prostate cancer cell lines by mass spectrometry
Authors: Ludwig Megan L. , Day Abderrahman , Bergom Hannah E. , Sychev Zoi , Horrmann Alec , Hwang Justin , Drake Justin M.
Published: March 2024

Multiple subtypes of prostate cancer can emerge in advanced stages of disease, such as tumors that maintain androgen receptor features (AR+), those without AR but with neuroendocrine features (AR-/NE+), and those without AR or NE features (AR-/NE-). These latter subtypes are particularly aggressive and incredibly lethal. Extracellular vesicles (EVs) are small particles that are mediators of cell-cell communication and have been nominated as potential biomarkers of disease state. We hypothesized that the proteome of EVs contains information about their originating cell that can distinguish between prostate cancer subtypes. To address this, we isolated EVs from cell lines of differing subtypes – AR+ (LNCaP, LNCaP95, C4-2, 22RV1), AR-/NE+(NCI-H660, EF1, LASCPC-01), and AR-/NE- (PC3, DU145) – and prepared the EV proteome for quantitative, label-free mass spectrometry analysis. This identified 2,000+ proteins in the EVs for each cell line where EVs from similar subtypes clustered together. Interestingly, we also found that EVs contained enough protein information to utilize developed gene signatures for AR or NE activity. EVs isolated from AR-/NE+ cells contained known NE signature proteins such as SYP, CHGA, and UCHL1. EVs from the AR+ cell lines displayed >50% AR activity driven by PSA and STEAP1 proteins in addition to other significant distinguishing protein markers. This supports the potential for using the proteome of tumor-derived EVs to identify novel signature molecular markers besides those already known to the field for developing liquid-based biomarker assays. In addition, our work characterizes the EV surfaceome which is critical for enriching signals from tumor-derived EVs feasible for clinical diagnostics assay development. While PSMA has been a reliable marker for cells reliant on AR signaling, less is known about protein markers in the AR- subset. Our work highlights TROP2 as especially enriched in the EVs from AR-/NE- cell lines, supporting its relevance as a target in patients without treatment options. To evaluate disease outcomes, further clinical studies are needed to develop specific and sensitive tests based on the EV proteome derived from advanced prostate cancer patients.

Citation Format: Megan L. Ludwig, Abderrahman Day, Hannah E. Bergom, Zoi Sychev, Alec Horrmann, Justin Hwang, Justin M. Drake. Characterizing the proteome landscape of extracellular vesicles from prostate cancer cell lines by mass spectrometry [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 6965.
Abstract 7040: Mutations in cytoskeleton genes SPTAN1/SPTBN1 serve as novel predictive markers for immunotherapy against bladder cancer
Authors: Kuo Brian Yu-Ting
Published: March 2024

Cancer progression is often driven by somatic mutations. Despite several well-known driver mutations, more evidence has shown that genetic alterations in cytoskeleton organization enhance tumor aggressiveness and promote cancer progression, suggesting their roles as potential drivers. In this study, pan-cancer genetic analyses by using TCGA cohorts, more frequent mutation events were found in cytoskeleton-related genes as compared to total annotated genes, especially in cancers derived from hollow organs. High-dimensional analysis of molecular alterations in cancer (HD-MAC) suggested gene mutations in SPTAN1 and its partner SPTBN1 as potential prognostic biomarkers for clinical outcomes of patients with bladder cancer. Gene knockdown in either SPTAN1 or SPTBN1, mimicking silencing mutations in cancer tissues, caused cell morphology changes, DNA breaks, and alternations in cytokine profiles via activating cGAS-STING mediated interferon signaling. Xenograft tumor models also indicate accelerated tumor growth in SPTAN1- or SPTBN1-silenced cells, suggesting a more advanced cancer type. Based on immune staining in both human and mouse samples, increased CD8+ T cell infiltration was in tumor lesions with mutations or truncations in SPTAN1/SPTBN1 genes. In addition, several known substitution mutations were found as potent neo-antigens based on MHC II binding prediction, which could be utilized as targets for immune checkpoint therapy. This study provides a novel insight into how the cytoskeleton can contribute to cancer progression and find out predictive biological indicators with therapeutic values.

Citation Format: Brian Yu-Ting Kuo. Mutations in cytoskeleton genes SPTAN1/SPTBN1 serve as novel predictive markers for immunotherapy against bladder cancer [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 7040.
Abstract 7046: Proteogenomic and immunologic profiles of head and neck cancer patients of African ancestry
Authors: Yang Fan , Chen Fanghui , Shay Chloe , Saba Nabil F. , Teng Yong
Published: March 2024

Blacks/African Americans (BAAs) with head and neck squamous cell carcinoma (HNSCC) have worse survival than Whites. However, the complex molecular biomarkers and signatures of HNSCC among BAAs and molecular distinction associated with HNSCC disparities are largely unknown. Here we show the results of a multi-omics analysis of 500 patients (48 BAAs and 452 Whites). Comparative analyses between the racial groups were performed at the level of genomics, pathways, molecular subtype, tumor immune infiltration, protein alterations and prognosis. We found that overall survival in BAAs with HPV-unrelated HNSCC is significantly shorter than in White patients. Ancestry-related differential mutation spectrum, DNA methylation, gene and protein expression pattern and immune infiltration landscape were identified. Particularly, FAT1 mutation is significantly associated with its gene expression in BAA HNSCC and poor overall survival in this group. In BAA HNSCC, SALL3 gene expression is positively associated with its gene CNVs, while RTP4 gene expression is inversely correlated with its methylation. High EGFR_pY1068 and RAD50 levels correlate with poor prognosis in BAAs with HNSCC. The immune infiltration enrichment scores of Th17 cells, activated dendritic cells, monocytes and neutrophils in BAA HNSCC were significantly lower than those in White HNSCC. By combining multi-omics analysis and data validation using in-house-made tumor tissue arrays, this study comprehensively elucidates the genetic landscape, immune response, and tumor biology in BAA and White HNSCC patients, providing a molecular basis for future research in identifying appropriate screening modalities and therapeutic interventions leading to improved outcomes in BAAs with HNSCC.

Citation Format: Fan Yang, Fanghui Chen, Chloe Shay, Nabil F. Saba, Yong Teng. Proteogenomic and immunologic profiles of head and neck cancer patients of African ancestry [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 7046.
Abstract 7060: Mitochondrial metabolism and racial disparity of bladder cancer
Authors: Kami Reddy Karthik Reddy , Park Jun Hyoung , Bollag Roni J. , Terris Martha K. , Lerner Seth P. , Siddiqui Minhaj , Lotan Yair , Gao Jianjun , Kaipparettu Benny Abraham , Putluri Nagireddy
Published: March 2024

Bladder cancer mortality is significantly higher in African American patients compared to their European American counterparts. This inferior survival of African American cancer patients is driven at least in part by distinctive intrinsic tumor biology, more specifically altered metabolic activity. However, underlying molecular mechanism for the African American bladder cancer mortality are largely unexplored. Our pioneering metabolomic findings demonstrate alterations in metabolic pathways between African American and European American bladder cancer, specifically those involved in driving energy metabolism. Along these line, we observed increased electron transport chain activity and ATP production in African American bladder cancer could be a result of distinctive rewiring of energy metabolism compared to their European American counterparts. We further performed gene set enrichment analysis by mapping metabolites to genes and observed that oxidative phosphorylation pathway was uniquely enriched in African American tumors compared to European American tumors. In addition, from in vitro assays, mitochondrial complex protein and activity were altered in African American bladder cancer. To determine the role of glutamine mediated increased electron transport chain activity and ATP production in African American bladder cancer, we evaluated the metabolic flux using 13C labeled tracers in both African American and European American bladder cancer cell lines. Metabolic flux analysis revealed that African American cell lines are more glutamine dependent and that producing increased tricarboxylic acid intermediates. Overall, our data indicate that elevated mitochondrial metabolism and oxidative phosphorylation driven by enhanced glutaminolysis may facilitate African American bladder cancer progression. These findings provide the rationale to use mitochondrial-specific inhibitors to target at least a subset of African American bladder cancer patients.

Citation Format: Karthik Reddy Kami Reddy, Jun Hyoung Park, Roni J. Bollag, Martha K. Terris, Seth P. Lerner, Minhaj Siddiqui, Yair Lotan, Jianjun Gao, Benny Abraham Kaipparettu, Nagireddy Putluri. Mitochondrial metabolism and racial disparity of bladder cancer [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 7060.