Abstract
Immunotherapy has revolutionized clinical care for many cancers, yet these treatments fail to control disease in many patients and new strategies are needed to improve anti-tumor immunity ...and enhance response rates. There is great need for an increased understanding of the cellular crosstalk within tumors and the identification of stromal and immune populations involved in shaping the tumor microenvironment (TME). Local immunosuppression (LIS) is one of the striking hallmarks of Pancreatic Ductal Adenocarcinoma (PDAC), a disease that is highly resistant to existing immunotherapies. Oncogenic Kras activation in tumor cells promotes the invasion and proliferation of tumor-supporting stromal cells, while excluding cancer-targeted cytotoxic T cells. LIS is mediated by multiple subtypes of cancer-associated fibroblasts (CAFs) and myeloid cells resident within the tumor parenchyma. Multiple prior attempts to reverse LIS in PDAC by targeting individual stromal cell populations have been unsuccessful, alluding to the complexity of stromal crosstalk within the TME. The stromal diversity of PDAC complicates investigating paracrine cascades involving multiple cell types. To decipher diverse drug effects on altering the TME, we employ in vivo studies in mouse models recapitulating the human disease, as well as a novel tumor explant model that enables the short-term culture of intact human or murine PDAC. Importantly, PDAC explants maintain their histopathological architecture and cellular diversity over time. This medium-throughput platform allows for testing of multiple drugs and mechanistic hypotheses in the native PDAC TME. We show in preliminary data that Smoothened inhibition (SMOi) decreases proliferation and activity of myCAFs, but provokes the expansion of CD11b-positive myeloid cells in vivo. Thus, we hypothesize that LIS in PDAC is maintained by a delicate balance between myCAFs and myeloid cells, preventing effective T cell invasion. Single cell RNA-seq data comparing ctrl vs. SMOi-treated murine PDAC elucidates stromal subpopulations involved in the LIS phenotype and guides the identification of myeloid subtypes emerging after SMOi. Strikingly, we demonstrated that simultaneous SMOi and targeting myeloid cells via anti-Gr1 or CCR1 inhibition (CCR1i) significantly elevates cytotoxic T cell numbers within the TME. We are currently investigating whether the activity of these T cells may be further potentiated through combination with immunomodulatory agents. By testing various treatment combination in the same TME, we will identify the best synergistic effects for future immunotherapy approaches in human PDAC. In summary, we are elucidating the complex mechanism behind LIS in PDAC by employing our novel explant culture system alongside in vivo studies. We aim to develop a translatable regimen to neutralize LIS, reactivating the cytotoxic T cells in the tumor periphery to invade, proliferate, and attack cancer cells.
Citation Format: Marie C. Hasselluhn, Lukas J. Vlahos, Dafydd Thomas, Alvaro Curiel Garcia, Amanda R. Decker, Tanner C. Dalton, Stephen A. Sastra, Carmine F. Palermo, Andrea Califano, Kenneth P. Olive. Combination CAF/myeloid targeting in PDAC abstract. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C032.
Abstract Sensitivity to therapeutic agents is impacted both by genetic heterogeneity between patients or among clones within a tumor and by heterogeneity of epigenetic cell states. Prior work ...demonstrates that human pancreatic tumors comprise malignant cells in a mixture of multiple cell states with distinct genetic dependencies, leading to a reservoir of chemoresistance across the tumor; targeting just one or two malignant cell states is insufficient to achieve durable therapeutic responses. One approach to overcome this challenge is to identify agents with efficacy against malignant cells in multiple cell states. However, in the absence of genetic distinctions between cell states, identifying therapeutic vulnerabilities for each malignant cell state present in a patient’s tumor in real time remains a challenge. OncoTreat is a CLIA certified algorithm that matches drugs to patients based on tumor gene expression profiles. The approach utilizes regulatory network analysis, a systems biology framework that transforms gene expression data into regulatory protein activity profiles, in a manner that facilitates the identification of master transcriptional regulators of cell state. We carried out a Phase 1 clinical trial of the OncoTreat framework to examine feasibility for implementing RNA-based precision medicine in patients with metastatic pancreatic ductal adenocarcinoma (2nd line and beyond). Patient-derived xenografts were established from subjects prior to 1st line therapy, and selected agents matched by OncoTreat were assessed co-clinically while subjects received standard of care regimens, with the potential for subsequent treatment with successful agents upon progression. Two subjects in the study matched to selenexor, an XPO1 inhibitor that is FDA approved for multiple myeloma. Co-clinical studies of selinexor in patient-derived xenograft models generated from the matched subjects showed prolonged survival compared to control regimens. Single-cell RNA sequencing analysis of these tumors found that the activity of master regulators confirmed that the activity of selinexor-responsive master regulators were inverted in response to treatment in vivo, reducing the fraction of malignant cells in the tumors. Strikingly, selenexor treatment was associated with significant inhibition of RAS/MAPK signaling, suggesting a potential novel role for selinexor targeting Ras. Together, these data indicate a potential therapeutic vulnerability for a subset of PDAC patients that can be predicted by a CLIA-certified RNA-based precision medicine platform. Citation Format: Alvaro Curiel-Garcia, Lorenzo Tomassoni, Tanner C. Dalton, Amanda R. Decker-Farrell, Carmine F. Palermo, Daniel R. Ross, Stephen A. Sastra, Urszula N. Wasko, Isabel M. Goncalves, Prabhot Mundi, Basil S. Bakir, Rachael A. Safyan, Hanina Hibshoosh, Gulam A. Manji, Andrea Califano, Kenneth P. Olive. RNA-based precision medicine predicts sensitivity to selinexor in select pancreatic ductal adenocarcinoma patients 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 934.
Abstract More than 90% of pancreatic ductal adenocarcinoma (PDAC) cases are driven by activating mutations in KRAS that drive it into an active, GTP-bound state (KRAS(ON)), producing excessive ...signaling via MAPK and other effector pathways. RMC-7977 is a potent inhibitor of GTP-bound RAS proteins (RAS(ON)), including both wild type and mutant variants of KRAS, NRAS, and HRAS. The related investigational agent, RMC-6236, is a first-in-class, potent, orally bioavailable, RASMULTI(ON) inhibitor currently in Phase 1/1b clinical trials (NCT05379985). Exposure to RMC-7977 suppressed the MAPK biomarker p-ERK, reduced cell growth, and induced apoptosis in multiple human RAS-addicted cancer cell lines. Assessment of RMC-7977 in a series of PDAC preclinical model systems revealed broad anti-tumor activity and treatment was well tolerated at translatable doses. The K-rasLSL.G12D/+, p53LSL.R172H/+, Pdx1Cretg/+ (KPC) autochthonous mouse model was utilized to study the effects of Ras-GTP inhibition in both tumor and normal tissues. At doses that drove anti-tumor activity, RMC-7977 dosing produced a metronomic effect on RAS signaling in tumor and normal tissue, with full pathway inhibition at 4 h post treatment that was restored by 24 h. This pattern yielded tumor-selective effects on apoptosis and proliferation, consistent with RAS oncogene addition in PDAC. RMC-7977 treatment drove regressions and an unprecedented ~3-fold extension of overall survival in KPC mice. After an initial response, all tumors eventually developed resistance on treatment, affording the opportunity to study acquired resistance mechanisms to RAS-GTP inhibition. Strikingly, in all resistant tumors, acute inhibition of MAPK and PI3K signaling was still apparent following treatment. These results indicate that RAS signaling re-activation mechanisms that have been reported as clinical mechanisms of resistance to mutant-selective KRASG12C inhibitors (e.g. second-site mutations or upregulation of upstream RTK) may be insufficient to confer resistance to a compound that inhibits all RAS isoforms. Rather, in this model we observed activation of alternative oncogenic mechanisms downstream of RAS effector signaling, including frequent focal amplification of Myc, focal amplification of Jun, and/or activation of Yap/Taz/Tead signaling in most resistant KPC tumors. Together these results demonstrate preclinical activity of RMC-7977 at tolerable doses, producing unprecedented responses even in highly chemoresistant PDAC models such as the KPC mouse. The observed range of potential resistance mechanisms suggests that RAS-GTP inhibition imposes a narrow evolutionary path to the development of acquired resistance in this context. These preclinical findings may help inform the ongoing development of investigational RAS inhibitors and the design of potential combinatorial treatment strategies to forestall resistance. Citation Format: Urszula N. Wasko, Jingjing Jiang, Yingyun Wang, Lorenzo Tomassoni, Lingyan Jiang, Marie Menard, Alvaro Curiel-Garcia, Tanner C. Dalton, Margo Orlen, Cole Edwards, Clint Stalnecker, Julien Dilly, Stephanie Chang, Stephen A. Sastra, Carmine F. Palermo, Timour Baslan, Sha Tian, Matthew Holderfield, Elsa Quintana, Zhengping Wang, Jacqueline A. Smith, Andrea Califano, David Wildes, Andrew J. Aguirre, Robert H. Vonderheide, Ben Z. Stanger, Scott W. Lowe, Channing J. Der, Mallika Singh, Kenneth P. Olive. Resistance to RAS-GTP inhibition in models of pancreatic ductal adenocarcinoma arises downstream of RAS effectors 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 1927.
Because a genetic diagnosis can guide clinical management and improve prognosis in critically ill patients, much effort has gone into developing methods that result in rapid, reliable results. The ...authors describe extremely rapid sequencing and analysis of the genomes of 12 patients, 5 of whom received a diagnosis.
Previous studies have failed to identify mutations in the Wilson's disease gene ATP7B in a significant number of clinically diagnosed cases. This has led to concerns about genetic heterogeneity for ...this condition but also suggested the presence of unusual mutational mechanisms. We now present our findings in 181 patients from the United Kingdom with clinically and biochemically confirmed Wilson's disease. A total of 116 different ATP7B mutations were detected, 32 of which are novel. The overall mutation detection frequency was 98%. The likelihood of mutations in genes other than ATP7B causing a Wilson's disease phenotype is therefore very low. We report the first cases with Wilson's disease due to segmental uniparental isodisomy as well as three patients with three ATP7B mutations and three families with Wilson's disease in two consecutive generations. We determined the genetic prevalence of Wilson's disease in the United Kingdom by sequencing the entire coding region and adjacent splice sites of ATP7B in 1000 control subjects. The frequency of all single nucleotide variants with in silico evidence of pathogenicity (Class 1 variant) was 0.056 or 0.040 if only those single nucleotide variants that had previously been reported as mutations in patients with Wilson's disease were included in the analysis (Class 2 variant). The frequency of heterozygote, putative or definite disease-associated ATP7B mutations was therefore considerably higher than the previously reported occurrence of 1:90 (or 0.011) for heterozygote ATP7B mutation carriers in the general population (P < 2.2 × 10(-16) for Class 1 variants or P < 5 × 10(-11) for Class 2 variants only). Subsequent exclusion of four Class 2 variants without additional in silico evidence of pathogenicity led to a further reduction of the mutation frequency to 0.024. Using this most conservative approach, the calculated frequency of individuals predicted to carry two mutant pathogenic ATP7B alleles is 1:7026 and thus still considerably higher than the typically reported prevalence of Wilson's disease of 1:30 000 (P = 0.00093). Our study provides strong evidence for monogenic inheritance of Wilson's disease. It also has major implications for ATP7B analysis in clinical practice, namely the need to consider unusual genetic mechanisms such as uniparental disomy or the possible presence of three ATP7B mutations. The marked discrepancy between the genetic prevalence and the number of clinically diagnosed cases of Wilson's disease may be due to both reduced penetrance of ATP7B mutations and failure to diagnose patients with this eminently treatable disorder.
Increasingly, youth experiencing mental health crises present to acute care medical hospitals and "board" on medical units due to inpatient psychiatric bed shortages. We conducted a retrospective ...cohort study of children experiencing mental health boarding at a US children's hospital from October 2020 to September 2022. We examined associations between patients' characteristics and their disposition and outcomes. Our cohort included 1891 boarding hospitalizations: 53.9% transferred to an inpatient psychiatric hospital and 46.1% discharged home. Characteristics associated with not being transferred to an inpatient psychiatric hospital included age <13 years (adjusted odds ratio aOR 0.6; 95% confidence interval CI: 0.4-0.7), disruptive or aggressive behavior (aOR 0.6; 95% CI: 0.4-0.8), psychosis (aOR 0.5; 95% CI: 0.3-0.8), COVID-19 infection (aOR 0.3; 95% CI: 0.2-0.6), or a complex chronic medical condition (aOR 0.8; 95% CI: 0.6-1.0). Our findings suggest that certain populations of children experiencing mental health boarding face disparate access to inpatient psychiatric care.
The aim of this study was to compare the effects of vibration (Vib versus noVib) during a maximal graded cycling exercise on hormonal response, precisely on cortisol (C) and testosterone (T). Twelve ...active males (25 #177; 5yrs; 181 #177; 5cm; 80.7 #177; 11.1kg) randomly performed two maximal incremental cycling tests on two separate days and at the same time of the day (09:00). The protocol consisted of incremental steps of 3 min duration performed on a PowerBIKE.sup.TM that induces vibration cycling. The study was a repeated measures design and participants performed the test with and without vibration. Gas exchange and heart rate (HR) were continuously assessed and blood lactate (Bla) was recorded at the end of each incremental stage. Saliva samples were collected before and immediately after the test, and analysed for (C) and (T). The results show that C and T increased in both cycling conditions; however, the C's magnitude of change was significantly higher by 83% after Vib cycling in comparison to the no Vib (p = 0.014), whereas the T's magnitude of change were not statistically different between trials (p = 0.715). Vibration induced a decrease of the T/C ratio (p = 0.046) but no significant changes were observed following noVib (p = 0.476). As a conclusion, the investigation suggests that adding mechanical vibration to cycling may potentiate a catabolic exercise-induced state, which could have potential clinical implications in rehabilitation and injury treatment. Sport experts should take this message home to carefully plan the recovery process and time during training and competitions.
Surface mount chip resistors are amongst the simplest and most inexpensive of all components used in electronic circuits and systems. Typically, resistor failure modes include open circuits, ...resistive shorts or variations in resistance indicating parametric drift or intermittent failure, which in some applications result in overall system failure. Corrosion is currently believed to be the number one failure mechanism for chip resistors deployed in developing markets such as Central and Latin America, Asia, India and Pacific regions where aggressive corrosive conditions are prevalent. The objective of this study is to develop a test to identify or screen out corrosion-susceptible parts. Ten precision chip resistors types representative of resistors in contemporary printed circuit board assemblies are subjected to a well-defined multi-stress screen which comprises thermal cycling and mixed flowing gas exposure. The combination of thermal cycling and corrosive gas exposure is shown to provide an acceptable acceleration test to identify corrosion-susceptible parts by replicating field failures. Currently, no other test method exists which is capable of replicating field failures.
Abstract Background Prognostic indices for patients with brain metastases (BM) are needed to individualize treatment and stratify clinical trials. Two frequently used tools to estimate survival in ...patients with BM are the Recursive Partitioning Analysis (RPA) and the diagnosis-specific Graded Prognostic Assessment (DS-GPA). Given recent advances in therapies and improved survival for patients with BM, this study aims to validate and analyze these two models in a modern cohort. Methods Patients diagnosed with BM were identified via our institution’s Tumor Board meetings. Data were retrospectively collected from the date of diagnosis with BM. Concordance of the RPA and GPA was calculated using Harrell’s C index. A Cox proportional hazards model with backwards elimination was used to generate a parsimonious model predictive of survival. Results Our study consisted of 206 patients diagnosed with BM between 2010 and 2019. The RPA had a prediction performance characterized by Harrell’s C index of 0.588. The DS-GPA demonstrated a Harrell’s C index of 0.630. A Cox proportional hazards model assessing the effect of age, presence of lung or liver metastases, and ECOG performance status score of 3/4 on survival yielded a Harrell’s C index of 0.616. Revising the analysis with an uncategorized ECOG demonstrated a C index of 0.648. Conclusion We found that performance of the RPA remains unchanged from previous validation studies a decade earlier. The DS-GPA outperformed the RPA in predicting overall survival in our modern cohort. Analyzing variables shared by the RPA and DS-GPA produced a model that performed analogously to the DS-GPA.
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