tbuckley/cabot-search huggingface dataset:
Abstract A053: The effects of chemotherapy on B cells and T cells in blood and tumor tissue in patients with pancreatic cancer – from diagnosis to terminal disease
Authors: Hedda Jacobsen
Journal: Cancer Research (2024)

Abstract Pancreatic cancer (PC) is a devastating disease and is almost always synonymous with a poor outcome. Chemotherapy is the standard treatment and is administered in either an adjuvant or palliative setting. However, nearly all patients, regardless of treatment intent, eventually develop chemoresistance. Little is known about the events causing chemoresistance, but increased knowledge is essential for improving patient outcomes. The aim of this study was to increase the knowledge of how the immune system, locally and systemically, is affected by chemotherapy and how this influences patient outcomes. Hence, immunohistochemical analysis of T and B cell prevalence in post-mortem tumor tissue was performed and combined with flow cytometric analysis of the dynamics of circulating T and B cell subsets during chemotherapy in nine PC patients enrolled in a clinical study. Despite the small number of patients included in this study, some interesting results were found. A high number of tertiary lymphoid-like structures (TLLSs) in the primary tumor was associated with shorter survival, which is contradictory to previous findings and possibly indicates a negative effect of chemotherapy on TLLSs. Certain subpopulations of T and B cells exhibited variations during treatment, possibly in response to chemotherapy. The frequency of T cells in blood also tended to correlate inversely with the frequency in primary tumor and liver metastases. Overall, this exploratory study provides insights into how the immune system in PC is affected by chemotherapy. Further study is warranted to shed more light on the intrinsic chemoresistance of PC and to identify new therapeutic strategies. Citation Format: Hedda Jacobsen. The effects of chemotherapy on B cells and T cells in blood and tumor tissue in patients with pancreatic cancer – from diagnosis to terminal disease [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A053.
Abstract A092: <i>Exploiting the neural-like properties of a new pancreatic cancer morpho-biotype for the development of a combinatorial treatment targeting tumor heterogeneity</i>
Authors: Giuseppe R. Diaferia, Pierluigi Di Chiaro, Francesca Fiumani, Lucia Nacci, Alessandro Zerbi, Paola Spaggiari, Iros Barozzi, Gioacchino Natoli
Journal: Cancer Research (2024)

Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers in which high intra-tumor heterogeneity and plasticity makes PDAC poorly responsive to available treatments. Coupling transcriptional profiling with laser capture microdissection of groups of cancer cells defined by distinct histological patterns, we were able to describe three PDAC “morpho-biotypes”. Such morpho-biotypes represent the combined morphological, molecular and functional properties of PDAC cells that coexist, in various proportions, in nearly all patients analyzed. Compared to single cells, our approach, that integrates morphological and spatial features, was able to clearly identify a novel morpho-biotype, primed toward a neural-like lineage differentiation. Only combining the expression of those genes able to discriminate all three morpho-biotypes, we achieved high prognostic power, underscoring the relevance of the co-existence of different cancer populations for clinical assessment. We therefore hypothesize that only combinatorial therapies, that target all the different biotypes simultaneously, can result in an effective cancer treatment. We identified an antiepileptic drug to be the best candidate to interfere with the neuronal-like program we unexpectedly found enriched in one of the PDAC morpho-biotypes. Using this drug with other oncogenic inhibitors specific for the other morpho-biotypes we obtained a complete stop of the tumor progression in a mouse model of xenografted human tumor fragments that maintained tumor heterogeneity. A similar neural progenitor-like signature was recently found enriched in single cell data form neo-adjuvant treated patients. This founding indirectly suggests that the new morpho-biotype we described in treatment-naïve patients could be responsible for the failure of the available treatments. This study not only contributes to our understanding of the effects of the combinatorial treatment, but also provides valuable molecular data for development of improved treatment schemes and histological maps that can guide pathologists’ diagnosis. Citation Format: Giuseppe R. Diaferia, Pierluigi Di Chiaro, Francesca Fiumani, Lucia Nacci, Alessandro Zerbi, Paola Spaggiari, Iros Barozzi, Gioacchino Natoli. Exploiting the neural-like properties of a new pancreatic cancer morpho-biotype for the development of a combinatorial treatment targeting tumor heterogeneity [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A092.
Abstract C033: The circadian rhythm gene Dec2 promotes pancreatic cancer dormancy by facilitating immune evasion
Authors: Lan Wang, Orjola Prela, Ching-Hua Shih, Juliana Cazarin de Menezes, Brian Altman, Paula Vertino, Chris Harris, Darren Carpizo
Journal: Cancer Research (2024)

Abstract Metastatic recurrence following curative-intent pancreatic cancer surgery is a major clinical problem as nearly all die of this at both early and latent periods following surgery. Latent recurrences are due to reactivation of dormant tumor cells that disseminate before the primary tumor has been removed. The mechanisms that drive cancer dormancy are poorly understood in part because of the lack of animal models that recapitulate the biology of the resected patient. Here we introduce a novel mouse model of pancreatic cancer dormancy in which we establish distal pancreatic tumors by orthotopic injection, resect them four weeks later and then follow the mice for recurrence. We observed recurrence patterns and survival outcomes that mimic human patients undergoing surgery for pancreatic cancer where two thirds of the mice succumb to early metastatic recurrence (median survival 26 days) and one third of the mice (called dormant mice) live substantially long (median survival 554 days) without clinical evidence of disease yet harbor disseminated tumor cells in most organs of the body. Disseminated tumor cells isolated from the livers of dormant mice were quiescent, exhibited stem cell properties and upregulated the expression of Dec2, a transcriptional repressor previously best known for its importance in maintaining circadian rhythms. Dec2 enabled the dormant tumor cells to evade the immune system by reducing the amount of MHC1 on their surfaces, and thereby lowered the number of CD8+ T cells within the tumor microenvironment. Knocking out Dec2 significantly improved the overall survival of immunocompetent mice and increased CD8+ T cell tumor infiltration. The decrease in cell surface MHCI was likely due to impaired surface localization of the protein. RNA-seq analysis demonstrated a loss of antigen presentation pathway genes in Dec2 WT cells, particularly in genes encoding subunits of the proteasome. Proper localization of MHC1 is known to depend upon proteasome-generated peptides. By cut-and-run analysis, Dec2 bound directly to the promoters of a number of proteasomal genes, lowered expression of these genes, and decreased proteasomal activity. These studies describe a new mechanism for Dec2 in regulating cancer dormancy through its downregulation of proteasomal activity which in turn converts a hot to a cold TME by decreasing cell surface MHC1. Citation Format: Lan Wang, Orjola Prela, Ching-Hua Shih, Juliana Cazarin de Menezes, Brian Altman, Paula Vertino, Chris Harris, Darren Carpizo. The circadian rhythm gene Dec2 promotes pancreatic cancer dormancy by facilitating immune evasion [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C033.
Abstract A007: Expression and activity of Rac, Cdc42, and their downstream effector PAK in Puerto Rican pancreatic cancer patients
Authors: Anamaris Torres-Sanchez, Jahdiel Berrios-Rodriguez, Jerry Cruz-Rodriguez, Jasmin Contreras-Santini, Victor Carlo, Suranganie Dharmawardhane
Journal: Cancer Research (2024)

Abstract Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed after the localized tumor has metastasized, which decreases its survival rate to a grim 3%. Mortality from PDAC is also increasing in Puerto Rico with lower survival rates than in the US. Therefore, it is pivotal to identify viable targets for the late stages of PDAC. The small GTPase Ras is the most mutated oncogene in PDAC. Oncogenic Ras, as well as multiple oncogenic cell surface receptors, activate the related GTPases Rac and Cdc42, which in turn activate p21-activated kinase (PAK) by autophosphorylation (p-PAK), to drive cancer cell invasion, and thus metastasis. Rac and Cdc42 are overexpressed in 21% of PDAC patients and contribute to poor prognosis. To determine the feasibility of treating PDAC with Rac/Cdc42 inhibitors that we are developing, this study aims to identify the p-PAK levels and Rac/Cdc42 expression in PDAC tissue from Puerto Rican patients. The hypothesis is that p-PAK levels, as well as Rac/Cdc42 expression, are selectively elevated in high-grade invasive PDAC. Immunohistochemistry for p-PAK and immunofluorescence for Rac/Cdc42 were conducted in fixed, paraffin-embedded PDAC biopsy samples of Puerto Rican patients. Preliminary results demonstrate that higher p-PAK levels are correlated with stage 3 and stage 4 tissue, and Rac and Cdc42 are expressed in ductal regions of PDAC tissue. Taken together, p-PAK has potential as a diagnostic biomarker for high-grade PDAC and will aid patient stratification in the planned clinical trials for our lead Rac/Cdc42 inhibitor, MBQ-167. Citation Format: Anamaris Torres-Sanchez, Jahdiel Berrios-Rodriguez, Jerry Cruz-Rodriguez, Jasmin Contreras-Santini, Victor Carlo, Suranganie Dharmawardhane. Expression and activity of Rac, Cdc42, and their downstream effector PAK in Puerto Rican pancreatic cancer patients [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A007.
Abstract C087: Window-of-opportunity trial of metastatic pancreatic cancer reveals mechanisms of response to targeting RAS signaling
Authors: Motoyuki Tsuda, Colin J. Daniel, Carl Pelz, Sam Sivagnanam, Dove Keith, Christopher L. Corless, Koei Chin, Lisa M. Coussens, Jonathan R. Brody, Charles D. Lopez, Gordon B. Mills, Rosalie C. Sears
Journal: Cancer Research (2024)

Abstract KRAS is mutated in ~85% of pancreatic ductal adenocarcinoma (PDAC) patients' tumors, suggesting that it is a key node of PDAC targeted therapy. RAF/MEK/ERK signaling is downstream of KRAS signaling. Preclinical studies targeting MEK showed promises but clinical trials failed to show the benefit compared to Standard-of-Care treatment chemotherapy. To elucidate the mechanism of action and resistance to several targeted therapies including MEK inhibition in human PDAC, we conducted a Window-Of-Opportunity trial for Metastatic pancreatic cancer (WOOM trial). In this trial, metastatic PDAC patients received 10 days of Cobimetinib, a FDA approved MEK inhibitor, therapy and specimens of pre- and post- treatment were obtained by biopsy to evaluate the response to targeted treatment using deep multi-omic analytics including DNA-seq, RNA-seq, multiplex IHC, cyclic IF and Digital Spatial Profiling (DSP). The clinical grade KI67 staining positivity was used as a readout of tumor response. We found three of 15 patients’ tumors had significantly decreased KI67 staining after MEKi treatment. Genomic sequence showed that two of three KI67-decreased patient’s tumors had KrasG12R mutations, which is significantly higher penetration compared to none of twelve KI67-non-responsive patient’s tumors. RNA-seq analysis showed that these KI67-decreased tumors are more classical-like compared to Ki67-non-responsive tumors. DSP analysis confirmed the downregulation of ERK phosphorylation after treatment in all examined cases. Moreover, MYC protein expression change is significantly correlated with KI67 protein expression change, which suggests MYC downregulation is the mechanism of action of MEK-inhibitor. Interestingly, MEK phosphorylation was upregulated after treatment in all examined cases. This suggests paradoxical RAF activation as a potential resistance mechanism. Furthermore, we found that Cobimetinib treatment changed the tumor microenvironment. Here, we summarize the multi-omics data and discuss the mechanism of response and resistance to target RAS signaling and related microenvironmental changes. Citation Format: Motoyuki Tsuda, Colin J. Daniel, Carl Pelz, Sam Sivagnanam, Dove Keith, Christopher L. Corless, Koei Chin, Lisa M. Coussens, Jonathan R. Brody, Charles D. Lopez, Gordon B. Mills, Rosalie C. Sears. Window-of-opportunity trial of metastatic pancreatic cancer reveals mechanisms of response to targeting RAS signaling [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C087.
Abstract C017: The anti-fungal itraconazole improves immunotherapy efficacy in pancreatic ductal adenocarcinoma by reversing the immune-suppressive tumor microenvironment
Authors: Sean Porazinski, Jennifer Man, Diego Chacon-Fajardo, Howard Yim, Emad El-Omar, Anthony Joshua, Marina Pajic
Journal: Cancer Research (2024)

Abstract Pancreatic cancer (PC) has 5-year survival rates of 11% and is projected to become the second leading cause of cancer-related deaths by 2030. Poor outcomes result from early metastasis and a lack of effectual therapies for advanced disease. Our previous large-scale genomics studies revealed PC is molecularly highly varied (1). This heterogeneity, lack of effective therapies and high mortality rate make PC a prime arena to advance personalised medicine strategies, where individual cancers are selected for optimal therapy depending on molecular subtype. Utilising our significant experience of molecular-guided anti-cancer therapies (2-6) and stromal biology expertise (2,6,7), we are taking drug-repurposing approaches to test agents with effects on stromal biology in combination with standard-of-care chemotherapies and immunotherapy, to improve clinical outcomes. Itraconazole is an FDA-approved anti-fungal with potential anti-cancer effects, although its efficacy in PC remains relatively unexplored. Preliminary in vivo findings indicate that itraconazole, in combination with standard-of-care chemotherapy gemcitabine/nab-paclitaxel, significantly delays disease progression in both mouse and patient-derived xenograft models of PC. Single cell RNA-seq analyses of tumors from the KPC orthotopic model of PC suggest itraconazole treatment can inhibit immunosuppressive aspects of the stroma and pro-tumorigenic, pro-metastatic signalling. Excitingly, combining itraconazole with anti-PD1/-CTLA4 immunotherapy provides significant survival advantages in the KPC orthotopic model of PC. Finally, using a model of metastatic PC, we show that itraconazole hinders metastatic colonisation in the liver. This work aims to identify subtypes of PC responsive to itraconazole allowing optimisation and translation of tailored therapies combining itraconazole and the latest clinically-utilised chemotherapies and immunotherapies. References1. Waddell, N. et al. Nature (2015). 2. Chou, A. et al. Gut (2018). 3. Li, L. et al. Br. J. Cancer (2020). 4. Belali, T. et al. BBA - GRM (2020). 5. Uzor, S. et al. Sci. Rep. (2021). 6. Porazinski, S. et al. Nature (2015). 7. Vennin, C. et al. Science Translational Medicine (2017). Citation Format: Sean Porazinski, Jennifer Man, Diego Chacon-Fajardo, Howard Yim, Emad El-Omar, Anthony Joshua, Marina Pajic. The anti-fungal itraconazole improves immunotherapy efficacy in pancreatic ductal adenocarcinoma by reversing the immune-suppressive tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C017.
Abstract C046: Enhancing T cell infiltration and migration in the pancreatic tumor microenvironment
Authors: Hongrong Zhang, Guhan Qian, Zhongming Chen, Branden Moriarity, Ingunn Stromnes, David Odde, Paolo Provenzano
Journal: Cancer Research (2024)

Abstract Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers, with a five-year survival rate only increasing from 6% to 12% in the last decade, indicating an urgent need for new therapeutic approaches. In recent years, immunotherapies like chimeric antigen receptor (CAR)-T cell therapy, have demonstrated promising therapeutic results in treating several hematological malignancies. However, the success has been limited in treating solid tumors, especially for PDAC. Factors contributing to this poor response include poor immunogenicity, highly heterogeneous and robust fibrotic and immunosuppressive tumor microenvironments (TMEs). Here, we used state-of-the-art imaging coupled with quantitative analysis to study dynamic T cell migration behavior in organotypic pancreatic tumor slices harvested from genetically engineered KPC mice. Our data showed that T cell speed and overall motility are both significantly lower in stroma-rich region PDA regions than observations in carcinoma cell-rich regions, where collagen fibers are loosely connected. Next, we utilized stroma-targeted approaches to deplete collagen and hyaluronan, the most abundant ECM components in the TME, to remove the biophysical barriers for effective immune therapy. Indeed, preliminary data demonstrated improved T cell infiltration and migration in the tumor slices in the STT-treated groups compared to the control groups. The observation is also confirmed with a therapeutic cell line generated with mesothelin-specific T cell receptors. Furthermore, we utilized genome engineering to generate CD8+ T cells that more effectively migrate in fibrous TMEs. Time-lapse imaging of the engineered T cells shows an increased 3D migration compared to control groups. Taken together, our data suggest that engineered T cell approaches in combination with stromal targeted therapies to diminish stromal ECM content have the potential to improve immunotherapy by allowing effector T cells to sample the tumor volume more effectively. Citation Format: Hongrong Zhang, Guhan Qian, Zhongming Chen, Branden Moriarity, Ingunn Stromnes, David Odde, Paolo Provenzano. Enhancing T cell infiltration and migration in the pancreatic tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C046.
Abstract C078: Inhibiting the autophagy-lysosomal pathway in pancreatic ductal adenocarcinoma using novel small molecules
Authors: Yangjingyi Ruan, Daniel W. Worroll, Grady Nelson, Yue-Ming Li
Journal: Cancer Research (2024)

Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers with a 5-year survival rate of 11.5% due to poor early detection and a lack of effective therapies. To meet the energetic demands, PDAC relies on autophagy to sustain growth and proliferation. Autophagy inhibitors such as hydroxychloroquine (HCQ) only showed limited autophagy inhibition in vivo and failed to provide clinical benefit to patients. However, studies have shown that the combination of HCQ and the MEK/ERK inhibitors can render better therapeutic results with stronger cytotoxicity. Our lab has designed and developed a class of small molecules (GN compounds) that target the autophagy-lysosomal pathway (ALP). Our GN compounds show autophagy inhibition and induction of extrinsic apoptosis markers by Western blot. Furthermore, GN64 affects the function of endosomes and lysosomes by immunofluorescence (IF). The combination treatment of GN79 and Binimetinib, a MEKi, inhibits the ALP and confers enhanced cytotoxicity in a panel of human PDAC cell lines. Future directions are aimed at determining the protein target and mechanism of GN compounds that leads to ALP inhibition. Completion of this project will advance the therapeutic development of novel ALP inhibitors and advance our understanding of the ALP with the possibility to imrpove the current therapeutic regimen for PDAC patients. Citation Format: Yangjingyi Ruan, Daniel W. Worroll, Grady Nelson, Yue-Ming Li. Inhibiting the autophagy-lysosomal pathway in pancreatic ductal adenocarcinoma using novel small molecules [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C078.
Abstract B095: Leukemia inhibitory factor fosters tumor growth in KRAS-driven pancreatic ductal adenocarcinoma
Authors: Lisa Miller-Phillips, Imene Boukhalfa Hanafi, Sarah Umetsu, Adam Olshen, Ritu Roy, Ashley Kiemen, Man-Tzu Wang, Eric Collisson
Journal: Cancer Research (2024)

Abstract While inflammation is a known and well-validated risk factor for developing pancreatic ductal adenocarcinoma (PDA), it remains unclear how Leukemia inhibitory factor (LIF), a cytokine of the IL-6 class family, influences tumor initiation and progression in PDA. LIF is highly upregulated in PDA when compared to the normal healthy pancreas. Using a human single-cell RNAseq PDA data set, we identified pancreatic cancer cells as the main source of LIF, followed by fibroblasts and stellate cells. After confirming that Pdx1-expressing cells represent the majority of Lif-expressing cells in the pancreas, we crossed our newly developed Lif flox/flox allele into the well-established KrasLSL-G12D/+, Trp53flox/flox, Pdx1-Cre (KPC) mouse model. Lif flox/flox, Pdx1-Cre (LC) mice present with normal pancreas histology, mouse weight, and mouse size at 12 months, indicating that Lif is dispensable for mouse pancreas development and function. Lif flox/flox, Trp53flox/flox, Pdx1-Cre (LPC) mice also showed no differences in pancreas histology when compared to normal Lif-expressing PC mice. Lif flox/floxKPC (LKPC) mice develop PDA tumors. Cell lines from LKPC tumors (n=4) presented with undetectable Lif expression and no LIF protein secretion. Control KPC tumor cell lines (n=4) showed Lif expression and LIF secretion, confirming the successful deletion of Lif in our newly developed mouse model. LKPC mice (n=21) showed a significant increase in disease-specific overall survival at 72 days when compared to control KPC mice (n=26) at 62 days (p&amp;lt;0.05). When mice reached endpoint, LKPC mice presented with significantly smaller tumors with an average tumor weight of 0.7g compared to KPC control animals with an average tumor weight of 1.3g (p&amp;lt;0.05). In summary, we find that cancer-cell expressed LIF augments tumor growth and shortens disease-specific overall survival, nominating leukemia inhibitory factor depletion as a promising therapeutic target in KRAS-driven pancreatic cancer. Citation Format: Lisa Miller-Phillips, Imene Boukhalfa Hanafi, Sarah Umetsu, Adam Olshen, Ritu Roy, Ashley Kiemen, Man-Tzu Wang, Eric Collisson. Leukemia inhibitory factor fosters tumor growth in KRAS-driven pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B095.