KRAS G13D Mutation Research Articles

Combination of farnesyl-transferase inhibition with KRAS G12D targeting breaks down therapeutic resistance in pancreatic cancer

Pancreatic adenocarcinoma is one of the deadliest forms of cancer with no effective therapeutic options. A KRAS mutation can be found in up to 90% of all pancreatic tumors, making it a promising therapeutic target. The introduction of new KRAS inhibitors has been a milestone in the history of KRAS mutant tumors; however, therapeutic resistance limits their efficacy. Thus, new therapeutic options, including combination therapies, are urgently needed. Recently, we have shown that KRAS G12C inhibitors in combination with farnesyl-transferase inhibitors exert synergistic antitumor effects. Here, we provide evidence for the feasibility of this combinational approach to break down resistance in KRAS G12D mutant pancreatic cancer. Although we have shown that the 3D environment dramatically sensitizes cells to MRTX1133 treatment, the synergistic effect of this drug combination is present in both 2D and 3D in the PANC1 pancreatic adenocarcinoma model, which showed high resistance to MRTX1133 in 2D. The effects of the combination treatment show an association with the inhibition of farnesylated regulatory proteins, including HRAS and RHEB, along with the expression level of KRAS. Our study warrants further investigation for the potential applicability of KRAS G12D inhibitors in combination with farnesyl-transferase inhibitors for the treatment of KRAS mutant pancreatic adenocarcinoma.

Abstract PR012: KRAS mutation-specific effects on the tumor immune microenvironment drive tumor progression in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with abysmal survival rates. The highly immunosuppressive microenvironment of PDAC poses a major barrier to effective therapy. KRAS mutations are near-ubiquitous in PDAC, and studies indicate clinical outcomes vary depending on the specific KRAS genotype. Given that tumor genotype can shape the immune cell composition of tumors, we examined the immune cell composition of pancreatic tumors with specific KRAS mutations, focusing on KRASG12D mutations (representing 40% of PDAC cases which have the worst prognosis) and KRASG12R mutations (which make up 20% of PDAC cases and have a better prognosis). Orthotopically implanted Kras G12R/+ ;Trp53 KO mouse pancreatic tumors have a distinct immune profile in comparison to Kras G12D/+ ;Trp53 KO tumors, characterized by an influx of intratumoral CD3+ T cells and mature dendritic cells. Selective depletion of CD4+ T cells induces a rapid progression in KRASG12R, but not KRASG12D mouse tumors. RNA sequencing of KRASG12R tumor cells revealed enrichment of Type I interferon (IFN) pathways accompanied by related chemokines, CXCL9 and CXCL10 in comparison to KRASG12D tumors. Analysis of publicly available and real-world human PDAC datasets and enrichment of dendritic cells and other immune related cell types in KRASG12R tumors. Collectively, these data link the KRASG12R mutation to a unique immunogenic role. Citation Format: Andrew Wenger, Tal Baron, Erika Hissong, Rohit Chandiwani, Lukas Dow, Despina Siolas, Katherine Bacchi, Huanhuan Sun, Erika Hissong, Adrian Vega, Whitney Sisso, and Kawther Abdilleh. KRAS mutation-specific effects on the tumor immune microenvironment drive tumor progression in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr PR012.

Characterization of A Bronchoscopically Induced Transgenic Lung Cancer Pig Model for Human Translatability.

There remains a need for animal models with human translatability in lung cancer (LC) research. Findings in pigs have high impact on humans due to similar anatomy and physiology. We present the characterization of a bronchoscopically-induced LC model in Oncopigs carrying inducible KRAS G12D and TP53 R167H mutations. Twelve Oncopigs underwent 29 injections via flexible bronchoscopy. Eighteen Adenovirus-Cre recombinase gene (AdCre) inductions were performed endobronchially (n=6) and transbronchially with a needle (n=12). Eleven control injections were performed without AdCre. Oncopigs underwent serial contrast-enhanced chest CT with clinical follow-up for 29 weeks. Following autopsy, lung and organ tissues underwent histopathology, immunohistochemistry, and RNA-sequencing with comparative analysis with The Cancer Genome Atlas (TCGA) human LC data. All 18 sites of AdCre injections had lung consolidations on CT imaging. Transbronchial injections led to histopathologic invasive cancer and/or carcinoma in situ (CIS) in 11/12 (91.7%), and invasive cancer (excluding CIS) in 8/12 (66.6%). Endobronchial inductions led to invasive cancer in 3/6 (50%). A soft tissue metastasis was observed in one Oncopig. Immunohistochemistry confirmed expression of Pan-CK+/epithelial cancer cells, with macrophages and T cells infiltration in the tumor microenvironment. Transcriptome comparison showed 54.3% overlap with human LC (TCGA), in contrast to 29.88% overlap of KRAS-mutant mouse LC with human LC. The transgenic and immunocompetent Oncopig model has a high rate of LC following bronchoscopic transbronchial induction. Overlap of the Oncopig LC transcriptome with human LC transcriptome was noted. This pig model is expected to have high clinical translatability to the human LC patient.

MGST1 facilitates novel KRASG12D inhibitor resistance in KRASG12D-mutated pancreatic ductal adenocarcinoma by inhibiting ferroptosis

BackgroundPancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer with a low 5-year survival rate. Treatment options for PDAC patients are limited. Recent studies have shown promising results with MRTX1133, a KRASG12D inhibitor that demonstrated potent antitumor activity in various types of tumors with KRASG12D mutation. Resistance to KRAS inhibitors is frequently occurred and one of the main reasons for treatment failure. Understanding resistance mechanisms to novel KRAS inhibitors is crucial to ensure sustained and durable remissions.MethodsTwo KRASG12D inhibitor MRTX1133-resistant PDAC cell lines were established in vitro. The resistance mechanisms to KRASG12D inhibitor MRTX1133 against PDAC in vitro and in vivo were characterized by RNA sequencing, reverse transcript polymerase chain reaction, cytotoxicity test, plasmid transfection, lentivirus transfection, lipid peroxidation detection, malondialdehyde levels detection, glutathione levels detection, western blot, immunofluorescence, nude mice tumorigenesis experiment and immunohistochemistry.ResultsThe bioinformatics analysis and transcriptome sequencing showed that ferroptosis was involved in the resistant effect of the KRASG12D inhibitor treatment, and MGST1 was the key molecule against MRTX1133-induced ferroptosis. Increased expression of MGST1 weakened the cytotoxicity of MRTX1133 by inhibiting lipid peroxidation-induced ferroptosis in KRASG12D inhibitor-resistant PDAC cells. Knockdown or overexpression of MGST1 conferred sensitivity or resistance to KRASG12D inhibitor MRTX1133, respectively. Mechanismly, increased nuclear localization and higher levels of active β-catenin were observed in MRTX1133-resistant PDAC cells, which contributed to higher MGST1 expression. Knockdown of CTNNB1 or TCF4 can decreased MGST1 expression. Additionally, we found that PKF-118-310, an antagonist of β-catenin/Tcf4 complex, repressed MGST1 expression. In both in vitro and in vivo models, a synergistic effect was observed when combining MRTX1133 and PKF-118-310 in KRASG12D inhibitor MRTX1133-resistant PDAC cells and tumors.ConclusionOur data showed that KRASG12D inhibitor MRTX1133 combined with PKF-118-310 could enhance the effectiveness of MRTX1133 treatment response through induction of ferroptosis via inhibiting MGST1 expression in MRTX1133-resistant PDAC cells and tumors. This evidence may provide a promising strategy to overcome KRASG12D inhibitor MRTX1133 resistance in PDAC patients with KRASG12D mutations.Graphical

KRASG12D-Mutated Metastatic Colorectal Cancer: Clinical, Molecular, Immunologic, and Prognostic Features of a New Emerging Targeted Alteration.

KRASG12D mutation (mut) occurs in about 10%-12% of metastatic colorectal cancer (mCRC). Recently, novel KRASG12D inhibitors have been developed and are currently under investigation in phase I/II clinical trials in solid tumors including mCRC. We aimed at performing a comprehensive characterization of clinical, molecular, immunologic, and prognostic features of KRASG12D-mutated mCRC to inform the design and the interpretation of future trials. We performed a pooled analysis of phase III TRIBE and TRIBE2 studies comparing 5-fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI)/bevacizumab (bev) to doublets (5-fluorouracil, leucovorin, and oxaliplatin or 5-fluorouracil, leucovorin, and irinotecan)/bev. One hundred and thirty-six (16%) of 854 patients with available KRASG12D mutational status were KRASG12D mutated. KRASG12D-mutated patients had more frequently right-sided primary tumor and were less likely to present liver-only metastases with respect to other RAS mutated and all-wild-type (wt) patients. Compared with the BRAFV600E-mutated group, KRASG12D-mutated patients had more frequently left-sided primary tumor, resected primary tumor at the time of diagnosis, and Eastern Cooperative Oncology Group performance status 0. KRASG12D-mutated patients had better prognosis than BRAFV600E-mutated and worse prognosis than all wt patients. No prognostic difference was evident between KRASG12D mut and other RAS mut patients overall or according to other specific KRAS or NRAS hotspot mutations. No interaction effect was observed between KRASG12D mut and the benefit provided by FOLFOXIRI/bev compared with doublets/bev. PIK3CA mut were reported more frequently among KRASG12D-mutated tumors compared with both other RAS mut and all wt. A detail estimation of KRASG12D mut mCRC patients' characteristics and expected outcomes may be useful when planning future studies in this subgroup. The high prevalence of PI3K/PTEN/Akt pathway activating alterations may affect the efficacy of targeted strategies.

Comprehensive structure-function analysis reveals gain- and loss-of-function mechanisms impacting oncogenic KRAS activity.

To dissect variant-function relationships in the KRAS oncoprotein, we performed deep mutational scanning (DMS) screens for both wild-type and KRASG12D mutant alleles. We defined the spectrum of oncogenic potential for nearly all possible KRAS variants, identifying several novel transforming alleles and elucidating a model to describe the frequency of KRAS mutations in human cancer as a function of transforming potential, mutational probability, and tissue-specific mutational signatures. Biochemical and structural analyses of variants identified in a KRASG12D second-site suppressor DMS screen revealed that attenuation of oncogenic KRAS can be mediated by protein instability and conformational rigidity, resulting in reduced binding affinity to effector proteins, such as RAF and PI3-kinases, or reduced SOS-mediated nucleotide exchange activity. These studies define the landscape of single amino acid alterations that modulate the function of KRAS, providing a resource for the clinical interpretation of KRAS variants and elucidating mechanisms of oncogenic KRAS inactivation for therapeutic exploitation.

Abstract A032: KRAS mutations have distinct effects on the tumor immune microenvironment in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with abysmal survival rates. The highly immunosuppressive microenvironment of PDAC poses a major barrier to effective therapy. KRAS mutations are near-ubiquitous in PDAC, and studies indicate clinical outcomes vary depending on the specific KRAS genotype. Given that tumor genotype can shape the immune cell composition of tumors, we examined the immune cell composition of pancreatic tumors with specific KRAS mutations, focusing on KRASG12D mutations (representing 40% of PDAC cases which have the worst prognosis) and KRASG12R mutations (which make up 20% of PDAC cases and have a better prognosis). Orthotopically implanted Kras G12R/+ ;Trp53 KO mouse pancreatic tumors have a distinct immune profile in comparison to Kras G12D/+ ;Trp53 KO tumors, characterized by an influx of intratumoral CD3+ T cells and mature dendritic cells. Selective depletion of CD4+ T cells induces a rapid progression in KRASG12R, but not KRASG12D mouse tumors. RNA sequencing of KRASG12R tumor cells revealed enrichment of Type I interferon (IFN) pathways accompanied by related chemokines, CXCL9 and CXCL10 in comparison to KRASG12D tumors. Analysis of publicly available human PDAC cohorts revealed enrichment of genes in inflammatory pathways in KRASG12R tumors. Collectively, these data link the KRASG12R mutation to an immunogenic role that is distinct from KRASG12D tumors. Citation Format: Andrew Wenger, Tal Baron, Adrian Vega-Perez, Whitney Sisso, Maria Paz Zafra, Lukas Dow, Despina Siolas. KRAS mutations have distinct effects on the tumor immune microenvironment in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2024 Oct 18-21; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2024;12(10 Suppl):Abstract nr A032.

Semaphorin 3D promotes pancreatic ductal adenocarcinoma progression and metastasis through macrophage reprogramming.

Axon guidance molecules are frequently altered in pancreatic ductal adenocarcinoma (PDA) and influence PDA progression. However, the molecular mechanism remained unclear. Using genetically engineered mouse models to examine semaphorin 3D (SEMA3D), we identified a dual role for tumor- and nerve-derived SEMA3D in the malignant transformation of pancreatic epithelial cells and invasive PDA development. Pancreatic-specific knockout of the SEMA3D gene from the KRASG12D and TP53R172H mutation knock-in, PDX1-Cre(KPC) mouse model demonstrated delayed tumor initiation, prolonged survival, absence of metastasis, and reduced M2 macrophage expression. Mechanistically, tumor- and nerve-derived SEMA3D indirectly reprograms macrophages through KRASMUT-dependent ARF6 signaling in PDA cells, resulting in increased lactate production, which is sensed by GPCR132 on macrophages to stimulate protumorigenic M2 polarization. Multiplex immunohistochemistry demonstrated increased M2-polarized macrophages proximal to nerves in SEMA3D-expressing human PDA tissue. This study suggests that altered SEMA3D expression leads to an acquisition of cancer-promoting functions, and nerve-derived SEMA3D is "hijacked" by PDA cells to support growth and metastasis in a KRASMUT-dependent manner.

Mutational analysis differentiating sporadic carcinomas from colitis-associated colorectal carcinomas

BackgroundUlcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) that is associated with increased risk of developing colitis-associated carcinoma (CAC). The genetic profile of CACs is fairly similar to the sporadic colorectal carcinomas (sCRCs), although showing certain differences in the timing and sequence of alterations that contribute to carcinogenesis. Also, both cancer types typically show a strong histological resemblance, which complicates the pathologists’ diagnosis. Due to the different clinical consequences, it is of utmost importance to categorize the corresponding cancer type correctly.MethodsIn this study, we determined the mutation profiles of 64 CACs and sCRCs in the hotspot regions of 50 cancer-associated genes and compared them to 29 controls to identify genetic gene variants that can facilitate the pathologists’ diagnosis. Pearson Chi-Square or Fisher’s exact tests were used for statistical analyses.ResultsWe found that sCRCs tend to mutate more frequently in APC and PIK3CA genes than CACs and that mainly males were affected. Our CAC cohort identified the KRAS G12D mutation as group-specific variant that was not detected in the sCRCs. When separating conventional from non-conventional CACs, it was discovered that the conventional type shows significantly more mutations for ATM.ConclusionsTaken together, our data highlights genetic differences between sCRC and CAC and enables the possibility to utilize specific gene alterations to support the pathologist’s diagnosis.

221 (PB209): Combination effect of the KRAS G12D-specific degrader ASP3082 with Cetuximab in xenograft models of colorectal and pancreatic cancer cells with KRAS G12D mutation

221 (PB209): Combination effect of the KRAS G12D-specific degrader ASP3082 with Cetuximab in xenograft models of colorectal and pancreatic cancer cells with KRAS G12D mutation

Abstract C025: A novel pan-RAS/β-catenin inhibitor, ADT-030, produces tumor regression in PDX models of pancreatic cancer

Abstract BACKGROUND: The absence of symptoms often leads to late diagnosis of pancreatic ductal adenocarcinoma (PDAC) limiting treatment options. Tumor cell proliferation and invasion/metastasis are usually driven by KRAS mutations and activation of Wnt/β-catenin pathway components. The recent approval of KRASG12C-specific inhibitors for lung cancer has validated RAS as a druggable target but has had limited application for PDAC given the rarity of this codon in PDAC. In addition, no Wnt/β-catenin inhibitors have been FDA approved. Thus, drugs which inhibit these important targets are urgently needed for PDAC and other cancers. Here, we describe treatment results with ADT-030, a novel dual pan-RAS/β-catenin inhibitor in murine models of PDAC and lung cancer. METHODS: In vitro assays of growth inhibition, colony formation, apoptosis, and cell cycle, along with western blotting for RAS signaling were performed to assess potency and selectivity of ADT-030. Murine 2838c3-Luc KRASG12D PDAC cells were implanted orthotopically into the pancreas of C57BL/6J mice and cells from two PDAC patient-derived xenograft (PDX) models harboring KRASG12D or KRASG12C mutations were implanted subcutaneously (SC) in NSG mice to evaluate the antitumor activity of ADT-030. ADT-030 was administered once daily by gavage 5x/week for 4 weeks. RESULTS: ADT-030 potently inhibited the growth of PDAC cells in vitro harboring the most prevalent KRASG12D mutation as well as those with KRASG12C. Annexin V assay revealed the capacity of ADT-030 to trigger apoptosis in KRAS mutant cells with minimal impact on BxPC3 RASWT cells. Cell cycle analysis using propidium iodide staining revealed that ADT-030 arrested cells in the G2/M phase. Other experiments showed that ADT-030 simultaneously suppressed both MAPK/AKT signaling and β-catenin transcriptional by inhibiting PDE10 and activating cGMP/PKG signaling. ADT-030 caused tumor regression in SC PDAC PDX mouse tumor models harboring either KRASG12D or KRASG12C mutations without discernable toxicity. Inhibition of orthotopic PDAC tumor growth by ADT-030 was dose-dependent, causing up to 80% reduction in tumor volume following a 4-week treatment period. In addition, ADT-030 significantly extended survival and yielded a high percentage of cures after stopping treatment in a murine model of KRAS- mutant lung cancer. CONCLUSION: ADT-030, novel dual pan-RAS/β-catenin inhibitor, showed strong and durable antitumor activity in clinically relevant and aggressive murine models of PDAC and lung cancer. ADT-030 is a promising development candidate for treatment of PDAC and other RAS-driven cancers, particularly given the complex KRAS mutation landscape of many cancers. Citation Format: Dhana Sekhar Reddy Bandi, Ganji P Nagaraju, Jeremy B Foote, Adam B Keeton, Xi Chen, Kristy L Berry, Yulia Y Maxuitenko, Upender Manne, Donald J Buchsbaum, Gary A Piazza, Bassel F El-Rayes. A novel pan-RAS/β-catenin inhibitor, ADT-030, produces tumor regression in PDX models of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C025.

Abstract C027: Efficacy advantages of a novel pan-RAS inhibitor, ADT-1004, over mutant- specific KRAS inhibitors for suppressing pancreatic tumor growth in murine models

Abstract Background/Objective: Prognosis remains grim for localized or metastasized pancreatic ductal adenocarcinoma (PDAC) with 5-year survival rates of 3-16%. More than 90% of PDAC cases harbor KRAS mutations. KRASG12C inhibitors recently developed have limited use for PDAC because only 3% of cases express this mutation. We developed a novel pan-RAS inhibitor, ADT-1004 and evaluated antitumor activity in tumor models established from murine or human PDAC cell lines or patient-derived xenografts (PDX). ADT-1004 is an orally bioavailable prodrug of ADT-007, a highly potent and selective pan-RAS inhibitor (doi.org/10.1101/2023.05.17.541233). Methods: Murine PDAC cells harboring the KRASG12D mutation (KPC-Luc or 2838C3-Luc) were orthotopically implanted into the pancreas of C57BL/6J mice. Four PDX PDAC tumors harboring KRAS mutations were implanted orthotopically in NSG mice. To assess potential to overcome RAS inhibitor resistance, parental KRASG12C MIA PaCa-2 PDAC cells and a resistant derivative of MIA PaCa-2 cells were implanted subcutaneously. To assess selectivity, mice were implanted with RASWT BxPC-3 cells SC. Mice were treated orally with ADT-1004 (40mg/kg) 5x/week for 4 weeks. Sotorasib and adagrasib KRASG12C inhibitors were administered at the same dose, route, and schedule as ADT-1004. Results: ADT-007 potently and selectively inhibited the growth of human and mouse PDAC cell lines in vitro. For example, the IC50 value of ADT-007 for KRASG12C MIA PaCa-2 PDAC cells was 2 nM compared to 2500 nM for RASWT BxPC-3 PDAC cells. Growth inhibition by ADT-007 was dependent on activated RAS and associated with reduced GTP-RAS levels and MAPK/AKT signaling. ADT-1004 was well tolerated in mice at doses up to 175 mg/kg bid orally with sustained plasma levels of ADT-007 exceeding growth IC50 values. ADT-1004 displayed robust antitumor activity in mouse tumor models using human- or mouse-derived PDAC cell lines with G12D, G12V, G12C, or G13Q KRAS mutations, causing selective inhibitory effects on ERK phosphorylation in tumors but not in normal tissues. ADT-1004 also inhibited growth of KRASG12C mutant MIA PaCa-2 tumors to a comparable extent as sotorasib and adagrasib. Sotorasib and adagrasib were ineffective against xenografted tumors of resistant cells derived from MIA PaCa-2 cells, while ADT-1004 strongly inhibited tumor growth. Target selectivity of ADT-1004 was confirmed in vivo, as ADT-1004 did not affect the growth of RASWT BxPC-3 tumors. Conclusions: ADT-1004 inhibited tumor growth of KRAS mutant PDAC tumors by blocking activated RAS to disrupt downstream MAPK/AKT signaling. Side-by-side comparisons reveal antitumor efficacy advantages of ADT-1004 over mutant-specific KRAS inhibitors. These results highlight the promise of ADT-1004 for treatment of PDAC and other RAS-driven cancers by addressing the complex genetic landscape of many cancers and limitations from resistance to mutant specific KRAS inhibitions. Citation Format: Dhana Sekhar Reddy Bandi, Ganji P Nagaraju, Jeremy B Foote, Adam B Keeton, Xi Chen, Kristy L Berry, Yulia Y Maxuitenko, Upender Manne, Donald J Buchsbaum, Gary A Piazza, Bassel F El-Rayes. Efficacy advantages of a novel pan-RAS inhibitor, ADT-1004, over mutant- specific KRAS inhibitors for suppressing pancreatic tumor growth in murine models [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C027.

Abstract A051: Innate immune cell dynamics and pancreatic tumor progression in alcoholic pancreatitis

Abstract Introduction: Persistent inflammation due to alcoholic chronic pancreatitis (ACP) is associated with pancreatic ductal adenocarcinoma (PDAC). Myeloid cell infiltration within the pancreas, particularly with oncogenic mutant KrasG12D/+ (*Kras), is crucial for driving PDAC carcinogenesis. Our previous work demonstrated that hyperactivation of cyclic AMP response element binding protein (CREB) accelerates ADM/PanIN progression with heightened fibroinflammation. However, the association between CREB in precursor neoplastic lesions and innate myeloid cells remains unclear. Methods: We established an ACP mouse model using an alcohol diet along with prolonged caerulein administration in Ptf1aCreERTM/+; LSL-KrasG12D/+ (KC), and CREB deleted [Crebfl/fl in KC (KCC-/-)] mice. Single-cell RNA sequencing (scRNA-seq) of the mouse pancreas, multiparametric immunophenotyping of tumor-infiltrating myeloid cells and chromatin immunoprecipitation (ChIP-seq) with CREB pulldown were performed. Cytokine arrays and qPCR studies followed co-culture assays using mouse neutrophils (J774M) and macrophages (RAW 264.7) with epithelial cell lines harboring *Kras with in vitro ACP induction were conducted. Results: ACP induction in KC mice led to increased infiltration of neutrophils and alternatively activated macrophages with the pancreas. Conversely, Creb-deleted mice exhibited significantly reduced myeloid cell infiltration despite ACP induction. ChIP-Seq and qPCR identified CREB-regulated chemokines and immunomodulators as mediators of myeloid cell trafficking. Co-culture of mouse neutrophils and macrophages with KC-ACP conditioned media significantly increased IL-1 receptor antagonist (Il-1ra) expression and secretion. Single-cell transcriptomic analysis revealed heightened Il1rn mRNA levels in neutrophils and macrophages in KC-ACP when compared with KC pancreatic tumors. Creb-deleted PDAC models showed strong downregulation of Il1rn in macrophages, confirming CREB’s role in modulating myeloid cell interactions via epithelial cell signaling. Conclusions: Our findings highlight that CREB activation in epithelial cells under ACP conditions facilitates crosstalk with myeloid cells, promoting IL-1ra upregulation in neutrophils and macrophages. This CREB-driven regulation of IL-1ra in myeloid cells contributes to inflammation-associated tumorigenesis. Targeting this axis may offer a novel therapeutic approach to curb pancreatic cancer progression. Citation Format: Siddharth Mehra, Sudhakar Jinka, Varun Krishnamoorthy, Supriya Srinivasan, Anna Bianchi, Andrew Adams, Haleh Amirian, Manan Patel, Jashodeep Datta, Nipun Merchant, Nagaraj Nagathihalli. Innate immune cell dynamics and pancreatic tumor progression in alcoholic pancreatitis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A051.

Abstract C010: Single-cell profiling unleashes KRAS-driven redrafting of the tumor microenvironment before cancer onset

Abstract Pancreatic cancer is a highly lethal and aggressive disease, commonly characterized by a unique tumor microenvironment, where mutant KRAS signaling plays a pivotal role in its pathophysiology. To deepen our understanding of KRAS-dependent signaling in earliest tumor development, oncogenic KRAS (KRASG12D) expression was induced in human stem cell-derived pancreatic ductal-like organoids (PDLOs), followed by time-resolved single-cell RNA and bulk ATAC sequencing. This unique precancerous state model facilitated a comprehensive characterization of early oncogenic events at cellular resolution. Furthermore, a machine learning approach was applied to accurately predict KRAS-dependent cell identities. Within seven days, mutated KRAS triggers distinct gene signature programs related to extracellular matrix remodeling and inflammation. Although derived from dysplastic yet non-cancerous states, these gene signatures negatively correlated with overall survival in PDAC (pancreatic ductal adenocarcinoma) patients. The KRAS-dependent signatures retrieved with the machine learning approach allowed the grouping of 24 published PDAC cases, showing differences in niche composition and communication patterns. Various co-culture systems demonstrated that KRASG12D-expressing PDLOs could activate pancreatic stellate cells, inducing a cancer- associated fibroblast (CAF)-like state. Simultaneously, these KRAS-activated organoids were protected from T cell infiltration in vitro. Furthermore, in silico approaches were employed to reconstruct a virtual pancreatic cancer space, demonstrating that our PDLOs transcriptionally bridge healthy and malignant ductal states. This also revealed potential KRAS-driven pathways mediating CAF activation and T cell shielding preceding cancer onset. In summary, our human PDLO model enables us to explore the transition from normal to cancerous states, addressing gaps in our understanding of tumor development and tumor niche preparation. Citation Format: Chantal Allgoewer, Markus Breunig, Meike Hohwieler, Medhanie Mulaw, Alexander Kleger. Single-cell profiling unleashes KRAS-driven redrafting of the tumor microenvironment before cancer onset [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C010.

11P Therapeutic effects of MRTX1133 in KRAS G12D mutant appendiceal cancer: Insights from organoid and in vivo studies

11P Therapeutic effects of MRTX1133 in KRAS G12D mutant appendiceal cancer: Insights from organoid and in vivo studies

Molecular Docking Study of Natural Compounds from Indonesian Medicinal plants as AKT and KRAS G12D Inhibitors Candidates

Resistance to anti-EGFR treatment in colorectal cancer may arise due to the loss of PTEN function or the presence of KRAS G12D mutation. These genetic events can lead to persistent activation of the PI3K-AKT or RAS-MAPK signaling pathways, respectively. Overcoming anti-EGFR resistance can be achieved by inhibiting these signaling pathways using AKT or KRAS G12D inhibitors. The exploration of plant-derived compounds with anticancer activity offers a promising avenue for discovering potential AKT or KRAS G12D inhibitors. Therefore, this study aimed to identify natural compounds from Indonesian medicinal plants that could be developed as AKT or KRAS G12D inhibitors using a molecular docking approach. The in-silico screening of natural compounds involved the utilization of oral drug parameters. Subsequently, the filtered natural compounds were docked into the binding sites of respective proteins. The analysis involved evaluating the AutoDock Vina scoring function and examining the ligand interactions with residues within the binding site to assess the potential of the natural compounds. The findings revealed that among the 1311 natural compounds from 320 Indonesian medicinal plant species, 274 compounds met the oral drug parameters and predicted to pose anticancer activities based on QSAR analysis. Notably, morindone and porphyrin demonstrated the highest potential for development as AKT inhibitors, while phaseollin exhibited the most potential as a KRAS G12D inhibitor.

Tuning assembled DNA nanoarchitecture into disassembled state to enhance accurate and ultrasensitive detection of KRAS G12D mutation

Cancer remains a formidable global health challenge, necessitating precise diagnostic tools. The KRAS gene, particularly the G12D mutation, holds pivotal clinical significance across various cancer subtypes. Existing DNA sensing techniques using single-stranded and double-stranded oligonucleotide probes are susceptible for enzymatic degradation, especially in complex biological samples like blood or serum. To address these challenges, we present an innovative approach that involves tuning assembled DNA nanoarchitecture into a disassembled state to accurate and ultrasensitive detection of the KRAS G12D mutation. Our method utilized a pair of multifunctional assembly hairpin probes to construct a DNA wire with both of a fluorophore labeled probe and a quencher labeled probe attached. Upon binding with the target DNA, the DNA wire undergoes gradual disassembly, separating all fluorophores from quenchers to significantly amplify fluorescence signals. This approach offers exceptional sensitivity and reaction kinetics, capable of detecting the KRAS G12D at femtomolar levels, and demonstrates outstanding specificity in discriminating single-base mutations. Furthermore, the DNA nanoarchitecture with well-demonstrated ability to nuclease resistance makes our method exhibits robustness in detecting KRAS G12D mutation in human serum samples. This innovative approach represents an advancement in cancer diagnostics, providing a promising tool for early disease diagnosis and biomedical study.

Targeting BCL2 with Venetoclax Enhances the Efficacy of the KRASG12D Inhibitor MRTX1133 in Pancreatic Cancer.

MRTX1133 is currently being evaluated in patients with pancreatic ductal adenocarcinoma (PDAC) tumors harboring a KRASG12D mutation. Combination strategies have the potential to enhance the efficacy of MRTX1133 to further promote cell death and tumor regression. In this study, we demonstrated that MRTX1133 increased the levels of the proapoptotic protein BIM in PDAC cells and conferred sensitivity to the FDA-approved BCL2 inhibitor venetoclax. Combined treatment with MRTX1133 and venetoclax resulted in cell death and growth suppression in 3D cultures. BIM was required for apoptosis induced by the combination treatment. Consistently, BIM was induced in tumors treated with MRTX1133, and venetoclax enhanced the efficacy of MRTX1133 in vivo. Venetoclax could also resensitize MRTX1133-resistant PDAC cells to MRTX1133 in 3D cultures, and tumors established from resistant cells responded to the combination of MRTX1133 and venetoclax. These results provide a rationale for the clinical testing of MRTX1133 and venetoclax in patients with PDAC. Significance: The combination of MRTX1133 and the FDA-approved drug venetoclax promotes cancer cell death and tumor regression in pancreatic ductal adenocarcinoma, providing rationale for testing venetoclax with KRASG12D inhibitors in patients with pancreatic cancer.

A phase I/II study of nanoliposomal irinotecan and carboplatin in patients with advanced or metastatic, poorly differentiated gastroenteropancreatic neuroendocrine carcinoma characterized by tissue and liquid next-generation sequencing.

52 Background: For locally advanced or metastatic gastroenteropancreatic neuroendocrine carcinomas (GEP-NECs), standard chemotherapy typically incorporates etoposide or irinotecan plus platinum agents. Herein, we initiate a phase I/II trial to apply Nal-IRI in combination with carboplatin as the 1st line treatment in patients with GEP-NECs to define the dose-limiting toxicity (DLT) and recommended phase II dose (RP2D). Methods: In the phase I part, traditional 3+3 design was applied. Enrolled patients would receive escalating dose of 60 (level -1), 80 (starting dose, level 0) or 100 (level 1) mg/m2 salt-form nal-IRI plus carboplatin AUC=4 with maximum total dose of 600 mg on D1, every 21 days as a cycle. DLTs were evaluated during the first one cycle of treatment with tumor assessment every 6 weeks. Prophylaxis G-CSF was not allowed in the first cycle Paired testing of tissue (TBx) and liquid biopsy (LBx) was done by Illumina TSO500 platform before treatment. The second LBx would be repeated for confirmed partial responders when progression. Results: Totally 6 GEP-NEC patients with primary sites of colon in three, and each one in esophagus, ampulla of Vater and pancreas were enrolled to level 0. One patient had DLT of grade 4 neutropenia lasting for 3 days even under salvage G-CSF. Treatment-related adverse events showed grade 3/4 neutropenia (33.4%), grade 2 anemia (16.7%), grade 3 fatigue (16.7%), and grade 2 skin rash (16.7%). Four patients achieved confirmed partial response and 2 patients got stable disease, with the objective response rate of 66.7% (95% confidence interval: 22%-96%). After the data and safety monitoring board meeting, level 0 was decided as RP2D but not escalation to level 1 because of acceptable toxicity profiles and promising efficacies. Comprehensive genomic profiling showed that driver mutations were identified in three cases including two harboring BRAFV600E mutation and one with KRASG12D mutation. The other three cases lacking driver mutation showed frequent copy number alteration including 1 with MDM2 amplification (copy number 27) and a wild-type TP53. Homologous recombination deficiency (HRD), as determined by GIS score, was identified in a colon GEP-NEC who remained to be HRD-positive at progression but a higher TMB (from 4.7 to 10.2 Muts/Mb) and a higher BRAFV600E mutation allele frequency (from 24.1% to 43.6%) in tumor tissue, compared to the baseline profiling. Conclusions: Based on current data, the RP2D is 80 mg/m2 of nal-IRI (salt-form) and carboplatin of AUC=4, every 3 weeks. The extension phase II study in GEP-NEC is ongoing. Clinical trial information: NCT05385861 .

A potent and selective pan-RAS inhibitor, ADT-1004, targeting complex KRAS mutations for pancreatic cancer.

90 Background: Pancreatic ductal adenocarcinoma (PDAC) is a challenging cancer with a 5-year survival rate of under 12%. More than 90% of PDAC cases involve KRAS mutations. KRASG12C inhibitors recently developed have limited use because only 3% of PDAC express this mutation, highlighting the urgent need for pan-RAS inhibitors to address the complex mutation landscape in PDAC while avoiding resistance mechanisms. We synthesized and evaluated a novel pan-RAS inhibitor, ADT-1004, in mouse tumor models transplanted with mouse PDAC cell lines or patient-derived xenografts. ADT-1004 is an orally bioavailable prodrug of ADT-007, a highly potent and selective pan-RAS inhibitor (doi.org/10.1101/2023.05.17.541233). Methods: Human and mouse PDAC cell lines were utilized to evaluate in vitro growth inhibitory potency and selectivity of ADT-007. For in vivo experiments, KPC-Luc (1 × 105) and 2838C3-Luc (1.5 × 105) PDAC cells harboring the KRASG12D mutation were injected into the pancreas of C57BL/6J mice. After one week, the mice were randomly divided into treatment groups (n = 7 per group) and received oral ADT-1004 at a dose of 40mg/kg body weight five times a week for 4 weeks. Tumor burden was assessed weekly by monitoring bioluminescence signals using the IVIS Xenogen imaging system. Four patient-derived xenografts from PDAC patients with KRASG12C, KRASG12D, KRASG12V, KRASG13Q mutations were subcutaneously implanted in NSG mice by a small incision in the right flank. A week later, when the tumors reached a size of 100mm3 mice were randomized (n=7 per group) and treated orally with 40mg/kg of ADT-1004 five times a week for 6 weeks. Body weight and tumor size were measured twice weekly. Results: ADT-007 potently and selectively inhibited the growth of human and mouse PDAC cell lines. For example, the IC50 value pf ADT-007 for KRASG12C MIA PaCA-2 PDAC cells was as low as 2 nM compared to 2500 nM for RASWT BxPC3 PDAC cells. Growth inhibition was dependent on activated RAS and associated with reduced GTP-RAS levels and MAPK/AKT signaling. ADT-1004 was well tolerated in mice at a dose up to 175 mg/kg bid orally with sustained plasma levels of ADT-007 far exceeding growth IC50 values. When administered orally at 40 mg/kg body weight, ADT-1004 displayed robust antitumor activity in mouse tumor models using patient or mouse derived PDAC cell lines with G12D, G12V, G12C, or G13Q KRAS mutations, causing significant inhibitory effects on ERK phosphorylation. Conclusions: ADT-1004 inhibited tumor growth of KRAS mutant PDA tumors by targeting activated RAS to disrupt downstream MAPK/AKT signaling. The results highlight the promise of ADT-1004 as a novel pan-RAS inhibitor and open new strategies for addressing the complex genetic landscape of PDAC and other RAS driven cancers.