Worse Outcomes In Patients Research Articles

Abstract PO3-27-02: A novel PTK6 PROTAC degrader induces apoptosis of drug resistant breast cancer cells

Abstract Background. PTK6/Brk, a non-receptor tyrosine kinase, is an oncogenic driver for several tumor types, including breast, prostate, liver, and pancreatic cancers. PTK6 is expressed in all breast cancer subtypes and higher levels of expression are associated with worse patient outcomes. The optimal approach to targeting PTK6 for therapeutic benefit has not been established. Although several inhibitors of PTK6 kinase activity have been developed, none have thus far been successfully translated to clinical trials. This may be in part due to kinase activity-independent functions of PTK6, for which there is growing evidence, that are not effectively targeted by traditional small molecule kinase inhibitors. Downregulation of PTK6 using shRNA inhibits growth, invasion/migration, survival and metastasis of breast cancer cells, including those that are resistant to standard therapies. PTK6 kinase inhibitor treatment phenocopies effects of PTK6 downregulation with respect to some, but not all PTK6-driven oncogenic activities. Moreover, growth of PTK6 CRISPR-targeted cells can be rescued either with wild type or catalytically inactive PTK6, supporting kinase activity-independent activities of PTK6 in regulating growth and viability of breast cancer cells. Therefore, PROTAC degraders may be a better way to chemically target and downregulate PTK6 expression in cancer, thereby phenocopying the effects of PTK6 shRNA. Methods. We developed a first-in-class PTK6 degrader using PROTAC (proteolysis-targeting chimeric) technology to target PTK6 expression in breast cancer cells of diverse subtypes. Degrader controls were also synthesized to assess specificity of MS105’s effects. Results. PTK6 degrader, but not degrader controls, potently downregulates PTK6 expression in multiple breast cancer cell types. Proteomic and kinome profiling confirm the specificity of our PTK6 degrader. PTK6 PROTAC degrader inhibits viability and induces apoptosis of PTK6-expressing breast cancer cells, whereas treatment with parent kinase inhibitor or degrader controls that do not engage PTK6 or E3 ligase have minimal effect. Treatment with PTK6 degrader, but not kinase inhibitor or degrader controls, induces expression of pro-apoptotic Bim, phenocopying the effects observed with PTK6 shRNA. In contrast, PTK6 degrader and kinase inhibitor are comparably effective in inhibiting cell migration, supporting the differential kinase dependency of PTK6-dependent oncogenic functions. Therefore, our PTK6 PROTAC degrader effectively inhibits both kinase-dependent and independent oncogenic activities of PTK6. Our studies support the development of PTK6 PROTAC degraders as a preferred approach to clinically targeting PTK6 in cancer. Citation Format: Hanna Irie, Criseyda Martinez, Yan Xiong, Alison Bartkowski, Jessica Byerly, Jian Jin. A novel PTK6 PROTAC degrader induces apoptosis of drug resistant breast cancer cells [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-27-02.

Abstract PO2-18-08: Identification of novel genetic/therapeutic vulnerabilities in breast cancer

Abstract Background: Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death among women worldwide. Triple negative breast cancer (TNBC) is an aggressive subtype that is defined by the lack of expression of estrogen and progesterone receptors in the absence of HER2 amplification or overexpression. TNBC represents 15-20% of all breast cancers and occurs more frequently in young premenopausal women. TNBC often ends with a poor clinical outcome due to high histological grade, rapid recurrence in many patients combined with few treatment options. These realities highlight the urgent need to identify novel therapeutics vulnerabilities that can be leveraged to improve TNBC patient outcomes. Methods: We utilized the publicly available DepMap and Kaplan Meier datasets to identify essential genes that were unique to TNBC cells and whose expression levels were associated with worse patient outcomes. siRNA based approaches were used to confirm the relevance of top hits in mediating cancer cell phenotypes including viability, cell-cycle profiles and induction of apoptosis among others. A novel drug currently being developed was identified for the top hit in these studies and was subsequently employed in multiple in vitro approaches to characterize the mechanisms of action in TNBC as well as initial efficacy studies using clinically relevant ex vivo patient derived models. Results: Using the DepMap database, we interrogated genome-wide sgRNA knockout screens conducted in over 40 breast cancer cell lines to identify specific genes whose expression was required for cell viability in TNBC cells, but not other breast cancer cell lines. This endeavor identified 6 genes (CTPS1, HUS1, PRKRA, RAD1, RAD9A and RHOA) that were preferentially essential in TNBC cells. Further profiling of these genes revealed that CTPS1 expression is higher in cancer relative to normal tissue and that its expression is further upregulated in chemotherapy- and PARPi-resistant models. Knockdown of CTPS1 in TNBC cells was shown to decrease cell proliferation and viability with no effects observed in estrogen receptor+ cell lines. Using a first-in-class, highly selective and orally bioavailable CTPS1 inhibitor (STP938) developed by Step-Pharma, we identified IC50s in the low nM range for many TNBC cell lines, including cell models that are resistant to existing standard-of-care therapies. Inhibition of CTPS1 was shown to arrest cells in S phase. Conclusions: Our studies have identified CTPS1 as an essential gene in TNBC. CTPS1 encodes an enzyme responsible for the catalytic conversion of UTP (uridine triphosphate) to CTP (cytidine triphosphate), an essential step in the biosynthesis of nucleic acids. These findings are timely in light of the recent and ongoing development of the first-in-class CTPS1 inhibitor, STP938, for which first-in-human studies are underway for refractory B- and T-cell lymphomas. Based on our initial studies using this drug, we provide pre-clinical evidence of its efficacy in multiple models of primary and advanced TNBC. Efforts are currently underway to move this work toward a clinical trial for TNBC patients. Citation Format: Xiyin Wang, Michael Emch, Lauren Voll, Rebecca Russell, Esther Rodman, Philip Beer, John Hawse. Identification of novel genetic/therapeutic vulnerabilities in breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-18-08.

Abstract PO5-24-09: Optimizing the Therapeutic Treatment of Breast Cancer Through a Dual Data-driven Theoretical Model

Abstract Despite rapid advancements in treatments and technology, breast cancer remains the second leading cause of cancer related morbidity in women in the US. As a heterogeneous disease, the unique genetic and phenotypic profile of each tumor complicates the prediction of treatment responses and optimized treatment strategies. One primary manifestation of phenotypic plasticity and concomitant intra-tumoral heterogeneity is the Epithelial-Mesenchymal Transition (EMT). The acquisition of migratory and invasive properties through EMT facilitates tumor metastasis and results in worse patient outcomes. As a result, the EMT and its reverse process (MET) often influence treatment response. However, the different mechanisms through which these therapeutic drugs affect the EMT-related phenotypic switching rates as well as each phenotype’s replication rates are unclear, and further investigation is required for better understanding their precise effect for directing optimal treatment strategies and improved patient outcomes. Here, we compile an atlas of publicly available metastatic and non-metastatic RNA sequencing data of breast cancer cell lines treated with therapeutic and chemotherapeutic drugs and propose a dual data-driven theoretical framework for understanding the effects of each drug on breast cancer treatment response. We infer the cell fractions, EMT phenotypic transition rates and phenotypic replication rates of each case through an extension of our previously developed hybrid data-driven and theoretical model, COMET. We infer single-cell RNA sequencing-derived EMT-related trajectories and apply a continuous time Markov chain model to infer inter-state transition rates. By analyzing the atlas of RNA sequencing data and integration with our framework, we gain novel insights into the context-specific mechanisms by which therapeutic drugs affect the phenotypic transition rates. This comprehensive understanding will contribute to optimizing breast cancer therapy and ultimately improving patient outcomes. Citation Format: A. Najafi. Optimizing the Therapeutic Treatment of Breast Cancer Through a Dual Data-driven Theoretical Model [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-24-09.

Improving patient outcomes following vital sign monitoring protocol failure: A retrospective cohort study.

Vital sign monitoring needs to be timely and correct to recognize deteriorating patients early and trigger the relevant clinical response. The aim of this study is to retrospectively evaluate compliance specifically toward the regional vital sign monitoring protocol the so called early warning score protocol (EWS-protocol) 72 h before a medical emergency team response (MET-response) and thereby illuminate whether poor compliance translates into a worse patient outcome. It was investigated all eligible patients that underwentMETresponses during the calendar year 2019. The inclusion criteria encompassed somatic patients above 18 years of age admitted to the hospital and detailed evaluations of the medical records of the included patients were conducted. Four hundred and twenty-nineMET-responses were included in the final analysis. EWS-protocol failure was observed for more than half the patients within all the time frames assessed. Thirty-day mortality was significantly higher for patients subject to EWS protocol failure in the timeframes 24-16, 16-8, 8-0 h before MET response. Adjusting for admission length, age, and gender, patients subject to EWS-protocol failure had an odds ratio (OR) of 1.9, 2.0, 2.1, 2.3 for mortality in the time frames 72-48, 24-16, 16-8, and 8-0 h before the MET-response, respectively. The adjusted OR for ICU-admission was 1.7, and 1.6 for patients subject to EWS-protocol failure in the time frames 16-8and 8-0 h before MET-response, respectively. According to all the data analysis in this article, there is evidence that compliance towardthe NEWS-protocol is poor. EWS-protocol failure is associated with a significant higher mortality and ICU-admission rate.

Machine Learning-Based Prediction of Malnutrition in Surgical In-Patients: A Validation Pilot Study.

Malnutrition in hospitalised patients can lead to serious complications, worse patient outcomes and longer hospital stays. State-of-the-art screening methods rely on scores, which need additional manual assessments causing higher workload. The aim of this prospective study was to validate a machine learning (ML)-based approach for an automated prediction of malnutrition in hospitalised patients. For 159 surgical in-patients, an assessment of malnutrition by dieticians was compared to the ML-based prediction conducted in the evening of admission. The model achieved an accuracy of 83.0% and an AUROC of 0.833 in the prospective validation cohort. The results of this pilot study indicate that an automated malnutrition screening could replace manual screening tools in hospitals.

Solutions for Addressing the Dermatologist Shortage in Rural Canada: A Review of the Literature.

In Canada, there is a maldistribution of dermatologists, with as many as 5.6 dermatologists per 100,000 population in urban areas and as low as 0.6 per 100,000 in rural areas. Considering trends of dermatologists to work in group practices in urban areas, and the low number of rural dermatologists, one solution may be to incentivize dermatologists to practice rurally. Several solutions using the following themes are discussed: dermatology program-specific incentives, dermatology practice-specific incentives, and other indirect incentives. The low number of dermatologists in rural areas in Canada is concerning and has negative consequences for access to care for patients in rural areas, ultimately resulting in worse patient outcomes. Future research is needed to evaluate the impact of these initiatives and assess future access to dermatological care.

Isthmin-1 alleviates cardiac ischemia/reperfusion injury through cGMP-PKG signaling pathway.

Ischemia/reperfusion (I/R) injury is an important complication of reperfusion therapy for acute myocardial infarction, extremely compromising the cardiac benefits of revascularization, however, specific and efficient treatment for cardiac I/R injury is still lacking. Isthmin-1 (ISM1) is a novel adipokine, and plays indispensable roles in regulating glycolipid metabolism and cell survival. The present study aims to investigate the potential role and molecular mechanism of ISM1 in cardiac I/R injury using gain- and loss-of-function approaches. Cardiac-specific ISM1 overexpression and silence were achieved using an adeno-associated virus serotype 9 system, and then these mice were subjected to I/R surgery, followed by biochemical test, echocardiography and histopathologic examinations, etc. Meanwhile, neonatal rat cardiomyocytes (NRCMs) with ISM1 silence or overexpression also received simulated I/R (sI/R) injury to further verify its role in vitro. The potential downstream pathways and molecular targets of ISM1 were screened by RNA-sequencing. We also treated injured mice and NRCMs with recombinant ISM1 (rISM1) to explore whether supplementation with ISM1 was sufficient to protect against I/R injury. Furthermore, acute myocardial infarction patients with percutaneous coronary intervention (PCI) and paired healthy controls were included to reveal the clinical relevance of circulating ISM1. Cardiac-specific ISM1 silencing aggravated while ISM1 overexpression alleviated I/R-induced acute cardiac injury and cardiac remodeling and dysfunction. Mechanistically, ISM1 targeted αvβ5 integrin to facilitate the nuclear accumulation of nuclear transcription factor Y subunit alpha, transcriptionally increased soluble guanylyl cyclase beta subunit expression, and eventually enhanced cGMP generation. Besides, we confirmed that treatment with rISM1 before or after reperfusion could confer cardioprotective effects in mice. Clinically, lower ISM1 levels post-PCI was associated with worse outcome in patients. ISM1 can protect against cardiac I/R injury through cGMP-PKG signaling pathway, and it is a promising therapeutic and predictive target of cardiac I/R injury.

Level One Trauma Center Proliferation May Worsen Patient Outcomes.

From 2013 to 2020, Arizona state trauma system expanded from seven to thirteen level 1 trauma centers (L1TCs). This study utilized the state trauma registry to analyze the effect of L1TC proliferation on patient outcomes. Adult patients age≥15 in the state trauma registry from 2007-2020 were queried for demographic, injury, and outcome variables. These variables were compared across the 2 time periods: 2007-2012 as pre-proliferation (PRE) and 2013-2020 as post-proliferation (POST). Multivariate logistic regression was performed to assess independent predictors of mortality. Subgroup analyses were done for Injury Severity Score (ISS)≥15, age≥65, and trauma mechanisms. A total of 482,896 trauma patients were included in this study. 40% were female, 29% were geriatric patients, and 8.6% sustained penetrating trauma. The median ISS was 4. Inpatient mortality overall was 2.7%. POST consisted of more female, geriatric, and blunt trauma patients (P < .001). Both periods had similar median ISS. POST had more interfacility transfers (14.5% vs 10.3%, P < .001). Inpatient, unadjusted mortality decreased by .5% in POST (P < .001). After adjusting for age, gender, ISS, and trauma mechanism, being in POST was predictive of death (OR: 1.4, CI:1.3-1.5, P < .001). This was consistent across all subgroups except for geriatric subgroup, which there was no significant correlation. Despite advances in trauma care and almost doubling of L1TCs, POST had minimal reduction of unadjusted mortality and was an independent predictor of death. Results suggest increasing number of L1TCs alone may not improve mortality. Alternative approaches should be sought with future regional trauma system design and implementation.

Psychiatric Diagnosis Does Not Influence Management or Resolution of Confirmed Fracture-Related Infection.

The purpose of this study was to determine if the presence of a standing Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, psychiatric diagnosis is associated with worse outcomes for patients who develop a confirmed fracture-related infection (FRI). Included patients had open or closed fractures managed with internal fixation and had confirmed FRIs. Baseline demographics, injury information, and outcomes were collected via chart review. All patients who had a diagnosis of psychiatric illness, which included depression, bipolar disorder, anxiety disorder, and schizophrenia, were identified. Patients with and without a psychiatric diagnosis were statistically compared. Two hundred eleven patients were diagnosed with a confirmed FRI. Fifty-seven (27.0%) patients had a diagnosis of a psychiatric illness at the time of FRI diagnosis. Patients with a psychiatric diagnosis had a higher rate of smoking (56% vs 40%, P=.039) and drug use (39% vs 19%, P=.004) and a higher American Society of Anesthesiologists (ASA) classification (2.35±1.33 vs 1.96±1.22, P=.038); however, there were no other demographic differences. Clinical outcomes also did not differ between the groups, as patients with an FRI and a psychiatric diagnosis had a similar time to FRI diagnosis, similar confirmatory FRI characteristics, and a similar rate of reoperation. Furthermore, there was no difference between patients with FRI with and without a psychiatric diagnosis regarding rate of infection resolution (89% vs 88%, P=.718) or time to final follow-up (20.13±24.93 vs 18.11±21.81 months, P=.270). The presence of a psychiatric diagnosis does not affect clinical outcomes in the patient population with FRI. This is the first study exploring the impact of psychiatric illness on patient outcomes after a confirmed FRI diagnosis. [Orthopedics. 202x;4x(x):xx-xx.].

Are measures and related symptoms of cachexia recorded as outcomes in gastrointestinal cancer chemotherapy clinical trials?

Cachexia is prevalent in gastrointestinal cancers and worsens patient outcomes and chemotherapy compliance. We examined to what extent registered gastrointestinal cancer chemotherapy clinical trials record measures and related symptoms of cachexia as outcomes, and whether these were associated with trial characteristics. Four public trial registries (2012-2022) were accessed for Phase II and/or III randomized controlled pancreatic, gastric, and colorectal cancer chemotherapy trial protocols. Trial outcome measures of overall survival and toxicity/side effects, and those related to cachexia [physical activity, weight/body mass index (BMI), dietary limitations, caloric intake, lean muscle mass] and symptoms (appetite loss, diarrhoea, pain, fatigue/insomnia, constipation, nausea, vomiting, and oral mucositis) were extracted, along with the number and types of performance status and patient-reported outcomes (PROs) tools. Data were summarized descriptively. Chi-square tests examined associations between outcomes and trial characteristics (cancer type, trial location, funding source, PROs tools, and commencement year). Statistical significance was set at P<0.05. We included 540 trial protocols (pancreatic (35.2%), colorectal (33.3%) and gastric (31.5%)), with most trials from Europe (44.1%). Trial lead investigator was from academia (28.3%), industry (27.6%) and government (26.3%). Allied health professional involvement (26.9%) occurred at eligibility. Adjuvant therapy in trials was mainly treatment-related (68.1%). Additional medication included anti-nausea (2.2%) and analgesia (0.9%). Trial protocols mostly recorded overall survival (90.4%) and toxicity (78.9%), and the symptoms appetite loss (26.1%) and diarrhoea (19.1%), with the other symptoms recorded in <10% of the trials. Reporting of physical activity (P=0.001), dietary limitations (P=0.002), lean muscle mass (P=0.027), appetite loss (P<0.001), pain (P=0.001), nausea (P=0.012), and oral mucositis (P=0.049) varied depending cancer type. Toxicity/side effects (P=0.022), physical activity (P<0.001), appetite loss, nausea, and vomiting (all P<0.001), diarrhoea (P=0.010), pain (P=0.001), fatigue/insomnia (P=0.001) varied depending on the trial location. Trial funding was predominantly from private/industry (34.3%) and influenced the reporting of overall survival (P=0.049), weight/BMI (P=0.005), caloric intake (P=0.015), and pain (P=0.031). Performance status and PROs tools were mentioned in 91.2% and 46.3% of the trials, respectively. Trials that incorporated PROs tools were more likely to report cachexia related outcomes, except for overall survival, lean muscle mass, and oral mucositis. The proportion of trials measuring weight/BMI increased with trial commencement year (P=0.04). Cachexia-related outcomes were under-recorded in gastrointestinal cancer chemotherapy trials. As trial patients experience a high symptom burden, cachexia-relevant measures and symptoms should be assessed throughout the trial, and integrated with primary endpoints to support their progress.

Abstract 1394: The CXCL10-CXCR3 axis as Jekyll and Hyde: A regulator of metastasis and immune response in osteosarcoma

Abstract The CXCL10-CXCR3 axis is known to promote tumor growth and metastasis via autocrine signaling, while it can also elicit anti-tumor responses by paracrine signaling. However, its roles are still elusive in osteosarcoma (OS), the most common malignant bone tumor in children. In this study, we utilized in vitro assays, mouse models, and gene expression analysis to characterize the roles of the CXCL10-CXCR3 axis in OS. To understand the autocrine signaling, we performed in vitro phenotypic assays on three OS cell lines with and without CXCL10. The results showed that the chemokine increased AKT phosphorylation and tumor cell migration. Using a CRISPR-based CXCR3 deletion mutant, we demonstrated that the lack of the receptor inhibited OS tumor growth and pulmonary metastasis in an orthotopic xenograft mouse model. The results indicate that the CXCL10-CXCR3 axis is sufficient and necessary to promote aggressive phenotypes in OS via autocrine signaling. Next, using gene expression datasets from two cohorts of OS patients, we showed that high expression of CXCL10 or its cognate receptor CXCR3 was associated with a better prognosis. Since CXCL10 is known to recruit CXCR3+ immune cells to fight against cancer, we further found that the expression of the T cell marker CD3D was associated with a better prognosis. These results suggest that the chemokine may also play a protective role in osteosarcoma by recruiting anti-tumor immune cells via paracrine signaling. Lastly, we have previously reported that a high circulating level of CXCL10 correlates with a poor prognosis in osteosarcoma patients. In this study, we demonstrated that increasing the circulating CXCL10 level in immunodeficient orthotopic xenograft mouse models of OS did not significantly promote the development of pulmonary metastases, suggesting circulating CXCL10 may exert its chemotactic effect mainly on immune cells, not on tumor cells. Taken together, we propose a model that tumor expression of CXCL10 promotes osteosarcoma growth and metastasis development via autocrine signaling. The increase of the local level of CXCL10 attracts CXCR3+ immune cells to the tumor site and promotes anti-tumor function via paracrine signaling. Metastatic cells colonize the lungs and cause tissue damage and inflammation, which increases the production of CXCL10 in the circulation. The higher circulating CXCL10 recruits T cells away from the primary tumor site and indicates the occurrence of metastasis and, hence, correlates with a worse outcome in patients. Our research highlights the importance of understanding the opposite effects of CXCL10 on tumor and immune cells as well as in the tumor microenvironment and circulation. Identification of the mechanistic differences in the CXCL10-CXCR3 signaling between tumor and immune cells will provide a novel therapeutic approach against tumor cells while promoting anti-tumor immune response in OS. Citation Format: Benjamin B. Gyau, Xiang Chen, Junyan Wang, Margaret A. Clement, Angela M. Major, Jun Xu, M. John Hicks, Tsz-Kwong Man. The CXCL10-CXCR3 axis as Jekyll and Hyde: A regulator of metastasis and immune response in osteosarcoma [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 1394.

Abstract 1797: Investigating the significance of OXPHOS activity in non-small cell lung cancer brain metastases

Abstract Background: Brain metastasis is a common and devastating occurrence for patients with non-small cell lung cancer (NSCLC). NSCLC patients with brain metastases have a poor median overall survival of 2-3 months, highlighting the urgency for novel treatment strategies. One approach to understanding and potentially targeting metastasis is via cancer metabolism. During the metastatic cascade, cancer cells must survive and adapt to the differential nutrient environments they encounter, including the brain. The blood brain barrier limits the availability of many metabolites, leading metastatic cells to alter their nutrient use to survive. RNA sequencing analyses of NSCLC brain metastases suggest that increased oxidative phosphorylation (OXPHOS) may be one such metabolic adaptation in the brain. The aim of this study was to determine the necessity of OXPHOS activity as a metabolic adaptation for NSCLC cells to proliferate in the unique metabolic environment of the brain. Materials and Methods: NSCLC cells were cultured in media mimicking the metabolic environments of the brain and blood. Expression of mitochondrial markers were evaluated by immunoblot in cells cultured across media conditions. The effects of the OXPHOS inhibitor IACS-010759 were assessed by cell growth as well as stable isotope tracing with [U-13C] glucose. Patient derived xenografts (PDXs) were derived from a cohort of patients with NSCLC who underwent stable isotope tracing with [U-13C] glucose. Mice bearing subcutaneously implanted PDXs were treated daily with 5mg/kg IACS-010759 and metastatic burden was measured by flow cytometry and histology. Results: Tracing studies in patients revealed that high enrichment in OXPHOS-related metabolites in the primary tumor correlated with worse patient outcomes. Compared with other media conditions, cells cultured in media replicating the metabolic environment of the brain have increased expression of mitochondrial proteins, increased 13C glucose labeling in the TCA cycle, and a larger reduction in proliferation with IACS-010759 treatment. Using our PDX models, inhibition of OXPHOS with IACS-010759 had little effect on subcutaneous tumor growth but reduced metastasis in the lung and the brain. Conclusions: OXPHOS activity may be enhanced in NSCLC brain metastases due to the unique metabolic environment of the brain. This elevated OXPHOS activity may be necessary for NSCLC brain metastasis growth, as OXPHOS inhibition reduced metastasis in the brain. NSCLC cells may undergo mitochondrial biogenesis to support survival in this unique metabolic environment, and this may represent an area of therapeutic vulnerability for brain metastases. Citation Format: Nia G. Hammond, Massar Alsamraae, Mayher Kaur, Rachel Zuckerman, Brianna Chang, Robert Cameron, Aaron Dyas, Brandon Faubert. Investigating the significance of OXPHOS activity in non-small cell lung cancer brain metastases [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 1797.

Abstract 7539: First-in-class anti-PVR mAb NTX1088 advancing through Phase I: Safe and potent in restoring DNAM1 expression to enhance antitumor immunity

Abstract NTX1088, a first-in-class anti-PVR (CD155) mAb, is currently evaluated in a Phase 1, open-label, multi-center study (NCT05378425). The trial initiated at MD Anderson Cancer Center, and was expanded into additional sites, including City of Hope, Ochsner Health, Sheba Medical Center and Hadassah Medical Center. Study objectives are safety, dose-finding, and efficacy with focus on pharmacokinetics, pharmacodynamics, and biomarker discovery. NTX1088 is investigated as a single agent and in combination with the anti-PD1 mAb, pembrolizumab (Keytruda) in patients with advanced solid malignancies. Ongoing dose escalation demonstrates a safe profile across ascending dose levels. NTX1088 is a high affinity humanized IgG4-S228P mAb that binds PVR and blocks all known interacting receptors at a single nM EC50. PVR, is a highly upregulated membrane protein on numerous tumor cells. PVR expression has been associated with worse patient outcome, due to its central role in immune suppression. PVR’s impact is mediated through interaction with the key stimulatory receptor, DNAM1 (CD226), on T and NK cells, leading to internalization and degradation of DNAM1. PVR also interacts with the inhibitory immune checkpoint receptors, TIGIT, CD96 and KIR2DL5A. Blocking PVR by NTX1088 has multiple immune-stimulating roles, through restoration of DNAM1 immune activation function, while simultaneously neutralizing TIGIT, CD96 and KIR2DL5A inhibitory signals in immune cells. Importantly, DNAM1 downmodulation was recently identified as a key resistance mechanism to approved immune checkpoint inhibitors, and its restoration by NTX1088 is a novel MoA, not demonstrated previously by other therapies.In vitro, as a monotherapy, NTX1088 significantly increased immune cell activation, superior to TIGIT, CD112R, and PD1 antibody blockade, leading to a greater immune-mediated tumor cell killing, IFNγ secretion, and CD137 induction. Importantly, only NTX1088 was able to restore DNAM1 to the surface of immune cells. Synergy was obtained when NTX1088 was combined with PD1 blockers, or with the anti-CD112R mAb, NTX2R13.Syngeneic models of PVRK.O, demonstrated a complete immune-mediated tumor regression. Numerous humanized murine xenograft models were investigated whereby NTX1088 exhibited robust tumor growth inhibition as a standalone and in combination with PD1 blockade.In conclusion, PVR blockade by NTX1088 has a remarkable pre-clinical efficacy, suggesting a potential clinical breakthrough, based on its ability to simultaneously overcome multiple tumor escape mechanisms. First-in-human (FIH) trial is currently ongoing and biomarker analysis is showing initial mechanistic proof of concept for NTX1088 mode of action, including the restoration of DNAM1 surface expression on patients’ immune cells. This is the first case of surface DNAM1 elevation in clinical settings. Citation Format: Anas Atieh, Akram Obeidat, Alon Vitenshtein, Guy Cinamon, Keren Paz, Tihana Roviš, Paola Brilc, Ofer Mandelboim, Stipan Jonjic, Pini Tsukerman. First-in-class anti-PVR mAb NTX1088 advancing through Phase I: Safe and potent in restoring DNAM1 expression to enhance antitumor 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 7539.

Abstract 2770: A novel MIRO2/MYO9B/RhoA signaling axis controls tumor cell invasion and metastasis

Abstract Metastasis of cancer cells to vital organs remains the leading cause of cancer related deaths, emphasizing a strong need for actionable targets in advanced stage cancer. To address this, we study novel dysregulated mitochondrial signaling mechanisms that cells utilize to metastasize. Here, we focus on how outer mitochondrial membrane protein—Mitochondrial Rho GTPase 2 (MIRO2)—promotes tumor cell invasion and metastasis. Our previous work identified higher MIRO2 mRNA expression in cancer vs. normal patient samples in a multitude of cancer types, which correlated with worse patient outcomes. Furthermore, we demonstrated that MIRO2 was critical for prostate cancer cell growth and survival in vitro and in vivo. However, it remains unknown if MIRO2 only affects primary tumor growth or if this protein is important throughout tumor progression. Using siRNA mediated knockdown (KD) of MIRO2 we find MIRO2 KD ubiquitously reduces tumor cell invasion in breast, melanoma, pancreatic, and prostate cancer cells. Utilizing metastatic prostate and breast cancer models, we demonstrate that mice injected with MIRO2 shRNA cells have significantly lower metastatic burden compared to mice injected with control shRNA cells. To determine the mechanism that MIRO2 controls invasion and metastasis, we looked at which of the top protein-binding partners for MIRO2 may regulate tumor cell invasion. Of our top hits, we found that depletion of atypical myosin IXB (MYO9B) by siRNA most significantly reduced tumor cell invasion and phenocopied MIRO2 depletion. MYO9B has a well-defined role in controlling cell motility via inactivation of RhoA. Excitingly, we have found 1) MIRO2 KD results in increased active RhoA, phenocopying MYO9B KD, 2) dual ablation of MIRO2 and RhoA fully rescues tumor cell invasion, and 3) MIRO2 is required for MYO9B driven invasion. Taken together, we propose a novel signaling mechanism by which MIRO2 broadly promotes invasion and metastasis through MYO9B dependent inactivation of RhoA. Citation Format: Dillon P. Boulton, Connor J. Hughes, Valentina Vaira, Ajita Jindal, Masoom Raza, Stephen Connor Purdy, Shilpa Sant, Heide L. Ford, M. Cecilia Caino. A novel MIRO2/MYO9B/RhoA signaling axis controls tumor cell invasion and 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 2770.

Abstract 1878: CTPS1: An unexplored vulnerability in breast and ovarian cancer

Abstract Breast and ovarian cancer represent the most common cancer types in women worldwide and are among the top fatal cancers. Despite the use of cytotoxic chemotherapy and targeted agents, recurrence is frequent and survival rates for patients with advanced metastatic disease are dismal. These realities highlight the need to identify novel biomarkers and therapeutic vulnerabilities in such tumors and to develop alternative treatment strategies. We took an unbiased approach to tackle this problem in which we leveraged publically available (DepMap) and in-house generated genome-wide CRISPR screens conducted in over 1000 cancer cell lines. We initially focused on the identification of essential genes that were unique to triple-negative breast cancer (TNBC) cells and whose expression levels were associated with worse patient outcomes. This interrogation revealed six genes (CTPS1, RHOA, PRKRA, RAD9A, HUS1, and RAD1) meeting these initial criteria. The essentiality of these genes was validated using gene-specific siRNAs in a panel of TNBC cells and knockdown of CTPS1 was shown to elicit the most inhibitory effect. CTPS1 depletion resulted in a rapid S-phase cell cycle arrest followed by apoptosis, not only in TNBC cells but also in highly aggressive ovarian cancer cells which share many molecular features with TNBC. CTPS1 converts uridine triphosphate to cytidine triphosphate, forming an essential nucleic acid required for multiple cellular processes. CTPS1 mRNA expression was substantially elevated in tumor vs. normal tissue, for both breast and ovarian cancer. Using over 40 breast and ovarian cancer cell lines, RT-PCR analyses confirmed increased expression of CTPS1 in TNBC and most ovarian cancer cell lines compared to other disease sub-types and “normal” cell line/tissue controls. Interestingly, chemoresistant and PARP inhibitor-resistant models exhibited the highest levels of CTPS1 among all cells analyzed. We subsequently identified and acquired STP938, a first-in-class highly selective CTPS1 inhibitor being developed by Step-Pharma. STP938 was found to elicit potent anti-cancer effects at nM concentrations across many cell line and patient-derived models, in both 2D and 3D culture systems. RNAseq analysis in aggressive cell line models following STP938 treatment or CTPS1 knockdown revealed significant regulation of genes related to DNA replication and the cell cycle pathways suggesting that combinatorial/sequential treatments of STP938 with replication stress/DNA damage response related drugs may be synergistic. STP938 is currently being developed for the treatment of lymphoma, and our findings support the repurposing of STP938 for breast and ovarian cancer, an avenue that we are currently developing. Citation Format: Xiyin Wang, Michael Emch, Lauren Voll, Rebecca Russell, Esther Rodman, Nicole Pearson, Xiaonan Hou, Scott Kaufmann, Saravut Weroha, Philip Beer, John Hawse. CTPS1: An unexplored vulnerability in breast and ovarian 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 1878.

Abstract 6161: Investigating the relationships between race and socioeconomic status on the biology of ER+ breast cancer

Abstract Black women in the US have worse health care options, poorer educational opportunities, and decreased income quality which collectively contribute to an overall lower socioeconomic status (SES) compared to white women. Furthermore, although the incidence of estrogen receptor positive (ER+) breast cancer is similar for Black and white women in the US, Black patients have significantly worse outcomes. The field has traditionally focused on systemic factors such as SES to explain outcome disparities. Consequently, differences in the molecular biology between tumors from Black and White women remains a gap in knowledge in the field. Recent studies have found that Black cancer patients have a unique gene expression profile that may modulate treatment response. However, how SES contributes to these differences in molecular biology and whether these differences in SES alter treatment response remain unknown. One challenge to addressing these questions is that existing datasets significantly underrepresent Black women and are not sufficiently annotated to understand the complex interplay between molecular biology and SES. Here, we present analysis of RNA expression datasets from 60 ER+ patient tumors (38 Black, 22 White), with corresponding SES and patient outcome annotations which suggest that the ECM and TIME of ER+ breast cancer are influenced by race and factors of SES including BMI and community poverty burden. We further provide evidence that these alterations in the TME may also associate with worse patient outcomes. Citation Format: Jerry Tyler DeWitt, Elena Oropeza, Svasti Haricharan. Investigating the relationships between race and socioeconomic status on the biology of ER+ breast 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 6161.

Abstract 6628: Mapping the spatial and molecular determinants of macrophage heterogeneity in breast cancer

Abstract Tumor-infiltrating macrophages support critical steps in tumor progression, and their accumulation in the tumor microenvironment (TME) is associated with adverse outcomes and therapeutic resistance across human cancers. In the TME, macrophages adopt diverse phenotypic alterations, giving rise to heterogeneous immune activation states and induction of cell cycle. While the transcriptional profiles of these activation states are well-annotated across human cancers, the underlying signals that regulate macrophage heterogeneity and accumulation remain incompletely understood. Here, we leveraged a novel ex vivo organotypic TME (oTME) model of breast cancer, in vivo murine models, and human samples to map the determinants of functional heterogeneity of TME macrophages. We identified a subset of F4/80high Sca-1+ self-renewing macrophages maintained by type-I interferon (IFN) signaling and requiring physical contact with cancer-associated fibroblasts. We discovered that the contact-dependent self-renewal of TME macrophages is mediated via Notch4, and its inhibition abrogated tumor growth of breast and ovarian carcinomas in vivo, as well as lung dissemination in a PDX model of triple-negative breast cancer (TNBC). Through spatial multi-omic profiling of protein markers and transcriptomes, we found that the localization of macrophages further dictates functionally distinct but reversible phenotypes, regardless of their ontogeny. Whereas immune-stimulatory macrophages (CD11C+CD86+) populated the tumor epithelial nests, the stroma-associated macrophages (SAMs) were proliferative, immunosuppressive (Sca-1+CD206+PD-L1+), resistant to CSF-1R depletion, and associated with worse patient outcomes. Notably, following cessation of CSF-1R depletion, macrophages rebounded primarily to the SAM phenotype, which was associated with accelerated growth of mammary tumors. Our work reveals the spatial determinants of macrophage heterogeneity in breast cancer and highlights the disruption of macrophage self-renewal as a potential new therapeutic strategy. Citation Format: Nir Ben Chetrit, Xiang Niu, Jesus Sotelo, Ariel Swett, Vinagolu Rajasekhar, Maria Jiao, Caitlin Stewart, Priya Bhardwaj, Sanjay Kottapalli, Saravanan Ganesan, Pierre-Louis Loyher, Catherine Potenski, Kristy Brown, Neil M. Iyengar, Dilip D. Giri, Scott W. Lowe, John H. Healey, Frederic Geissmann, Irit Sagi, Johanna A. Joyce, Dan A. Landau. Mapping the spatial and molecular determinants of macrophage heterogeneity in breast 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 6628.

Abstract 3487: Molecular dynamic simulations of RAS family protein interactions: Mutant KRAS binding with wildtype HRAS and NRAS

Abstract Introduction: Mutations in the KRAS, HRAS, and NRAS genes are frequently associated with worse patient outcomes. Previous analyses of the structure and function of the associated proteins have been explored but not conclusively. The actual binding conformations of the three isoforms, especially when mutated are essential in designing inhibitory drugs. Recent studies have identified important interactions between the three isoforms that affect the oncogenic strength of the others when they are mutated. We use a bioinformatics approach to examine the modifications of the structural properties, mechanisms, and kinetic energies of eight KRAS mutants interacting with wildtype HRAS, and again with wildtype NRAS. Methodology: AlphaFold AI predicted models of KRAS, HRAS, and NRAS were downloaded from Uniprot and relevant mutations were induced using PyMOL. Pairs of KRAS mutants and either HRAS or NRAS were submitted to ClusPro for docking. PyMOL was used to separate proteins by chain identities before being repaired in GROMACS. Molecular dynamics simulations (MDS) were performed between proteins using GROMACS, a Linux based MDS software that renders a topology regulated by Newton’s Laws. XmGrace was used to analyze structure, MMPBSA.py was used to derive energy calculations, and VMD was used to visualize the interaction mechanisms. Results: RMSF data indicated C-terminus residues in KRAS mutants and WT-HRAS and WT-NRAS are the most mobile in their interactions. Notably, when WT-HRAS interacts with G12R, G12S, G12V, and Q61H, its C-terminus decreases fluctuation. G13D had the greatest binding strength and strength fluctuation with WT-HRAS. G12V had the greatest binding strength with WT-NRAS. All other mutants had weaker binding with WT-NRAS than WT-KRAS. WT-HRAS had stronger binding at residue Val187 with WT-KRAS than all mutants did. WT-HRAS residues Cys184, Lys185, and Cys186 each had weaker binding energies with WT-KRAS than most mutants did. WT-KRAS residues Gln25 and Lys117 both exhibited stronger binding energy in interactions with WT-HRAS than most mutants did. WT-NRAS had stronger binding at residues Met182 and Met189 with WT-KRAS than all mutants did. Residue Pro185 in WT-NRAS did not have significant interaction with WT-KRAS, but had a strong interaction with all mutants. WT-NRAS residue Val187 had weaker binding energy with WT-KRAS than most mutants. WT-KRAS residues Tyr32 and Asp38 both exhibited weaker binding energy in interactions with WT-NRAS than most mutants did. Conclusion: MDS between KRAS mutants and WT-HRAS and WT-NRAS present notable structural modification and binding kinetics. In each KRAS mutation, different segments of the protein complexes are involved in the interaction, indicating unique inhibitory methods are required to approach each mutant. Citation Format: Isaac Silverman, Michael S. Gerber, Aaron Shaykevich, Yitzchak F. Stein, Alexander Siegman, Sanjay Goel, Radhashree Maitra. Molecular dynamic simulations of RAS family protein interactions: Mutant KRAS binding with wildtype HRAS and NRAS [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 3487.

The Presence of Chronic Total Occlusion in Noninfarct-Related Arteries Is Associated With Higher Mortality and Worse Patient Outcomes Following Percutaneous Coronary Intervention for STEMI: A Systematic Review, Meta-Analysis and Meta-Regression.

Reperfusion therapy with percutaneous coronary intervention improves outcomes in patients with ST-elevation myocardial infarction. We conducted a meta-analysis to assess the impact of chronic total occlusion (CTO) in noninfarct-related artery on the outcomes of these patients. Comprehensive searches were performed using PubMed, Google Scholar, and EMBASE. The primary endpoint was the 30-day mortality rate, with secondary endpoints including all-cause mortality, repeat myocardial infarction, and stroke. Forest plots were created for the pooled analysis of the results, with statistical significance set at P < 0.05. A total of 19 studies were included in this meta-analysis, with 23,989 patients (3589 in CTO group and 20,400 in no-CTO group). The presence of CTO was associated with significantly higher odds of 30-day mortality [18.38% vs 5.74%; relative risk (RR), 3.69; 95% confidence intervals (CI), 2.68-5.07; P < 0.00001], all-cause mortality (31.00% vs 13.40%; RR, 2.79; 95% CI, 2.31-3.37; P < 0.00001), cardiovascular-related deaths (12.61% vs 4.1%; RR, 2.61; 95% CI, 1.99-3.44; P < 0.00001), and major adverse cardiovascular events (13.64% vs 9.88%; RR, 2.08; 95% CI, 1.52-2.86; P < 0.00001) than the non-CTO group. No significant differences in repeated myocardial infarction or stroke were observed between the CTO and non-CTO groups. Our findings underscore the need for further research on the benefits and risks of performing staged or simultaneous percutaneous coronary intervention for CTO in the noninfarct-related artery in patients with ST-elevation myocardial infarction.

The Roots and Clinical Effects of Racial Bias in Medicine

In a growing society, healthcare has become an essential part of a country’s development, standard of living, and life expectancy. The past decade has seen unprecedented growth in both scientific and medical discoveries, leading to improved treatment plans and innovative treatments, yet there are some aspects of healthcare that remain stunted. Discrimination, particularly on the basis of race, is still prevalent and ingrained in the American healthcare system, leading to worsened patient outcomes for people of color and a discomfort with seeking medical care that disproportionately affects those in marginalized groups. This bias continues even into the education of healthcare providers, which perpetuates the cycle of prejudice in the medical field. While the intersection of racism in the medical field varies greatly and maintains its prevalence amongst different races, this dissertation focuses mainly on discrimination of Black patients in the American healthcare system. For further information on the effects of racial bias both abroad and amongst a wider variety of races, valuable resources can be found below the works cited in this review. The sources analyzed in this review are analytical and scientific, with little to no use of primary anecdotal evidence. While such an emotional topic as racism and how it affects patient care relies heavily on personal experience, these sources have confounded the feelings of many patients nationally and adapted them into a well-reviewed analysis of how those feelings reflect nationwide opinions. Furthermore, it includes historical papers detailing the foundations of the medical field and how it was developed in hand with racism. The following sections will include definitions of terminology surrounding the issue, information on the history that led to modern-day biases, the ways in which these biases are seen by patients, and how it affects their care. This will demonstrate the link between past practices and the discriminatory actions in the medical system currently. Furthermore, it will establish evidence that there are effects felt by patients of color as well as offer information on possible solutions to help better their treatment.