Recent Studies Research Articles

Inflammatory factors secreted from endothelial cells induced by high glucose impair human retinal pigment epithelial cells

Abstract Objectives Diabetic retinopathy (DR) is a retinal disease that arises from impaired glucose tolerance and leads to retinal microvascular leakages. Recent studies have indicated that DR pathogenesis is linked to dysfunctional retinal pigment epithelial (RPE) cells. Methods Investigating the potential interplay between endothelial cells (ECs) and RPE cells by treating ECs with high glucose (HG) and evaluating the function of cytokines released from ECs on the growth of RPE cells. Results The results revealed that high glucose-stimulated Human Umbilical Vein Endothelial Cells (HUVECs) activated the NF-κB signaling pathway, increased intracellular levels of reactive oxygen species (ROS) and expression of caspase 3 while also elevating HUVECs delivery of cytokines such as VEGF, TNF-α, IL-6, and IL-1β. Conclusions As a result of our study, cytokines released from HG-treated HUVECs impede the growth of ARPE-19 in vitro, highlighting the importance of functional ECs for exploring the underlying mechanisms of vascular-associated retinal dysfunction. Inflammatory factors secreted from endothelial cells induced by high glucose impair human retinal pigment epithelial cells.

Revisiting the scattering regime map based on transport scattering coefficient for dielectric particulate medium

The independent scattering assumption is frequently employed in radiative transfer, as it is applicable to numerous scientific and practical scenarios involving sparsely distributed scatterers. However, dependent scattering effects must be considered if the particle distribution is not sparse, which requires a relatively more rigorous analysis. A scattering regime map that summarizes the conditions where the independent scattering assumption can be used safely was established in the 1980s. The validity of this regime map and corresponding transition criteria has been questioned due to revealed inaccuracies in certain portions of the map based on the recent experimental studies. This study aims to reevaluate the regime map for dielectric particulate medium through numerical simulations utilizing dense medium radiative transfer theory relying on static structure factor for incorporating the effects of dependent scattering. The transport scattering coefficient, encompassing both the scattering coefficient and the asymmetry parameter, is employed as the metric of evaluation as it accounts for both the quantitative and directional behavior of the scattering. Besides, it also reflects the behavior of reflectance/transmittance closely, which is presented by comparing the regime maps based on transport scattering coefficient and reflectance. While the resulting modified regime map agrees mostly with the established map, it corrects the parts where discrepancies were observed so that the modified map is in agreement with all available data. Moreover, the effects of particle size distribution and material properties are also investigated and it was found that a regime map for lower relative refractive index miss-match between particle and medium produces a demarcation line that is more conservative.

Identification of non-canonical antagonistic bacteria via interspecies contact-dependent killing.

Canonical biocontrol bacteria were considered to inhibit pathogenic bacteria mainly by secreting antibiotic metabolites or enzymes. Recent studies revealed that some biocontrol bacteria can inhibit pathogenic bacteria through contact-dependent killing (CDK) mediated by contact-dependent secretion systems. The CDK was independent of antibiotic metabolites and often ignored in normal biocontrol activity assay. In this study, we aimed to use a pathogen enrichment strategy to isolate non-canonical bacteria with CDK ability. Rhizosphere soil samples from Chinese cabbage showing soft rot symptom were collected and Pectobacterium carotovorum subsp. carotovorum (Pcc), the pathogen of cabbage soft rot, were added into these samples to enrich bacteria which attached on Pcc cells. By co-culture with Pcc, four bacteria strains (named as PcE1, PcE8, PcE12 and PcE13) showing antibacterial activity were isolated from Chinese cabbage rhizosphere. These four bacteria strains showed CDK abilities to different pathogenic bacteria of horticultural plants. Among them, PcE1 was identified as Chryseobacterium cucumeris. Genome sequencing showed that PcE1 genome encoded a type VI secretion system (T6SS) gene cluster. By heterologous expression, four predicted T6SS effectors of PcE1 showed antibacterial activity to Escherichia coli. Overall, this study isolated four bacteria strains with CDK activity to various horticultural plant pathogens, and revealed possible involvement of T6SS of Chryseobacterium cucumeris in antibacterial activity. These results provide valuable insight for potential application of CDK activity in biocontrol bacteria. © 2024 Society of Chemical Industry.

Sentiment Analysis of X(twitter) Data-a Review Study

Social networking Sites have captured the attention of the every generation. The advancement of technology and social networking sites has enabled anyone to easily express and share their ideas, opinions, feelings, expressions and reviews about any topic like- social, political, brands, business etc, with other people around the world. Thus Social media contains large amount of data in the form of text, image, audio and video uploaded by users. This data can be used as valuable information to check the reviews of people. It is also possible to diagnose every sentiment of the user by his/her text and posts on social media using emotion theories, machine learning techniques, and natural language processing techniques. This paper reviews the recent studies of sentiment analysis by social networking site X(Twitter). The steps of the methodology and related work analysis of the existing system is discussed in this review paper.

Moderate Message Passing Improves Calibration: A Universal Way to Mitigate Confidence Bias in Graph Neural Networks

Confidence calibration in Graph Neural Networks (GNNs) aims to align a model's predicted confidence with its actual accuracy. Recent studies have indicated that GNNs exhibit an under-confidence bias, which contrasts the over-confidence bias commonly observed in deep neural networks. However, our deeper investigation into this topic reveals that not all GNNs exhibit this behavior. Upon closer examination of message passing in GNNs, we found a clear link between message aggregation and confidence levels. Specifically, GNNs with extensive message aggregation, often seen in deep architectures or when leveraging large amounts of labeled data, tend to exhibit overconfidence. This overconfidence can be attributed to factors like over-learning and over-smoothing. Conversely, GNNs with fewer layers, known for their balanced message passing and superior node representation, may exhibit under-confidence. To counter these confidence biases, we introduce the Adaptive Unified Label Smoothing (AU-LS) technique. Our experiments show that AU-LS outperforms existing methods, addressing both over and under-confidence in various GNN scenarios.

Simultaneous Optimization of Bid Shading and Internal Auction for Demand-Side Platforms

Online advertising has been one of the most important sources for industry's growth, where the demand-side platforms (DSP) play an important role via bidding to the ad exchanges on behalf of their advertiser clients. Since more and more ad exchanges have shifted from second to first price auctions, it is challenging for DSPs to adjust bidding strategy in the volatile environment. Recent studies on bid shading in first-price auctions may have limited performance due to relatively strong hypotheses about winning probability distribution. Moreover, these studies do not consider the incentive of advertiser clients, which can be crucial for a reliable advertising platform. In this work, we consider both the optimization of bid shading technique and the design of internal auction which is ex-post incentive compatible (IC) for the management of a DSP. Firstly, we prove that the joint design of bid shading and ex-post IC auction can be reduced to choosing one monotone bid function for each advertiser without loss of optimality. Then we propose a parameterized neural network to implement the monotone bid functions. With well-designed surrogate loss, the objective can be optimized in an end-to-end manner. Finally, our experimental results demonstrate the effectiveness and superiority of our algorithm.

Towards Trustworthy Deep Learning

Deep neural networks (DNNs) have achieved unprecedented success across many scientific and engineering fields in the last decades. Despite its empirical success, unfortunately, recent studies have shown that there are various failure modes and blindspots in DNN models which may result in unexpected serious failures and potential harms, e.g. the existence of adversarial examples and small perturbations. This is not acceptable especially for safety critical and high stakes applications in the real-world, including healthcare, self-driving cars, aircraft control systems, hiring and malware detection protocols. Moreover, it has been challenging to understand why and when DNNs will fail due to their complicated structures and black-box behaviors. Lacking interpretability is one critical issue that may seriously hinder the deployment of DNNs in high-stake applications, which need interpretability to trust the prediction, to understand potential failures, and to be able to mitigate harms and eliminate biases in the model. To make DNNs trustworthy and reliable for deployment, it is necessary and urgent to develop methods and tools that can (i) quantify and improve their robustness against adversarial and natural perturbations, and (ii) understand their underlying behaviors and further correct errors to prevent injuries and damages. These are the important first steps to enable Trustworthy AI and Trustworthy Machine Learning. In this talk, I will survey a series of research efforts in my lab contributed to tackling the grand challenges in (i) and (ii). In the first part of my talk, I will overview our research effort in Robust Machine Learning since 2017, where we have proposed the first attack-agnostic robustness evaluation metric, the first efficient robustness certification algorithms for various types of perturbations, and efficient robust learning algorithms across supervised learning to deep reinforcement learning. In the second part of my talk, I will survey a series of exciting results in my lab on accelerating interpretable machine learning and explainable AI. Specifically, I will show how we could bring interpretability into deep learning by leveraging recent advances in multi-modal models. I'll present recent works in our group on automatically dissecting neural networks with open vocabulary concepts, designing interpretable neural networks without concept labels, and briefly overview our recent efforts on demystifying black-box DNN training process, automated neuron explanations for Large Language Models and the first robustness evaluation of a family of neuron-level interpretation techniques.

Impact of Drug-Mediated Inhibition of Intestinal Transporters on Nutrient and Endogenous Substrate Disposition…an Afterthought?

A large percentage (~60%) of prescription drugs and new molecular entities are designed for oral delivery, which requires passage through a semi-impervious membrane bilayer in the gastrointestinal wall. Passage through this bilayer can be dependent on membrane transporters that regulate the absorption of nutrients or endogenous substrates. Several investigations have provided links between nutrient, endogenous substrate, or drug absorption and the activity of certain membrane transporters. This knowledge has been key in the development of new therapeutics that can alleviate various symptoms of select diseases, such as cholestasis and diabetes. Despite this progress, recent studies revealed potential clinical dangers of unintended altered nutrient or endogenous substrate disposition due to the drug-mediated disruption of intestinal transport activity. This review outlines reports of glucose, folate, thiamine, lactate, and bile acid (re)absorption changes and consequent adverse events as examples. Finally, the need to comprehensively expand research on intestinal transporter-mediated drug interactions to avoid the unwanted disruption of homeostasis and diminish therapeutic adverse events is highlighted.

Abstract 3211: Development of first in class zip code drug conjugate in pancreatic ductal adenocarcinoma

Abstract Pancreatic ductal adenocarcinoma (PC) is the fourth most common cancer-related cause of death in Western countries. It is projected that PC will become the second most prevalent cause of cancer-related mortality by the year 2030. Although chemotherapy may offer certain advantages to those who have been diagnosed with pancreatic cancer, its effectiveness is notably constrained by the emergence of chemoresistance and excessive toxicity. In recent studies, it has been established that circulating tumor DNA (ctDNA) serves as a mechanism for cell-specific genetic transfer. We discovered that transposon sequences (known as Zip Codes, ZC) were responsible for ctDNA cell targeting. Therefore, we investigated the possibility of hijacking these ZC to deliver drugs specifically. We began by determining whether PDCA ZC synthesized chemically could target PDCA cells selectively. To achieve this, ZC sequences were labeled with CY5 for high-throughput microscopy. Results show that numerous PDCA-ZC were specific and efficient at targeting PC cell lines while sparing other cancer cell lines. The AluSc8 (PCZC) sequence was chosen for further investigation. The specificity of PCZC for targeting cells was validated using pancreatic islet cells. Based on these findings, we developed a technique for conjugating PCZC with SN38 via a CL2A linker. The results indicated that PCZC-SN38 was a very effective agent at killing PC cells (IC50: 1 μg), but not other cancer cell lines. The therapeutic efficacy of PCZC-N38 was evaluated in vivo using PDX (patient-derived xenografts, Garcia et al Plos One 2013). Maximum tolerated dose testing (MTD) (dosing from 1 to 21 mg of PCZC-SN38/Kg) failed to reach an MTD. Subsequently, we evaluated the efficacy signal of PCZC-SN38 by administering PCZC-SN38 to animals three times per week for three weeks at concentrations of 3 and 30 mg/kg of DNA (equivalent to 0.05 and 0.5 SN38 mg/kg). We used animals treated with vehicle, PCZC alone, and irinotecan (either once per week (50 mg/kg) or three times per week (0.5 mg/Kg) as a comparison. PCZC-SN38 decreased tumor growth by 41% and 70%, respectively, when compared to the vehicle or PCZC alone. The observed efficacy did not result in a change in body weight. In contrast, every animal administered irinotecan at a dosage of 50 mg/kg died within a week. On the contrary, animals that were given irinotecan at a dosage of 0.5 mg/kg demonstrated a growth inhibition of 60% and exhibited remarkable tolerability. Currently, research is being undertaken to determine the therapeutic efficacy of PCZC-SN38 at higher doses. The results outlined in this study illustrate the preliminary application of PC targeted drug delivery using a PC zip code drug conjugate. The results of our study demonstrate an innovative methodology for targeting PC cells specifically with therapeutic cargo material and supports further preclinical development of PCZC-SN38 for PC. Citation Format: Munnever Cinar, Purnachandra Ganji, Andrey Pisarev, Lourdes Martinez-Medina, Dhana S. Bandi, Pavan K. Puvvula, Steven Chang, Daniel Maneval, Bassel El-Rayes, Leon Bernal-Mizrachi. Development of first in class zip code drug conjugate in pancreatic ductal adenocarcinoma [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 3211.

Abstract 5682: Micro RNA level changes in prostate cancer cells treated with MDMX and MDM2 inhibitors

Abstract INTRODUCTION: Prostate Cancer (PCa) is the most common non-cutaneous cancer and the second leading cause of cancer death among men in the United States. Most of the PCa cases are diagnosed in men between the ages of 65-74. Due to the recent push for frequent prostate screenings, these cancers are being detected early and treated much faster, leading to a 5-year survival of a localized or regional PCa to >99%. However, the 5-year survival of PCa with distant metastasis is significantly reduced to 32%, especially with involvement of osteoblastic bone lesions, lung lesions, and brain lesions. Therefore, there is a clinical need to identify prognostic markers and new targets for developing therapies and effectively treating advanced PCa. Previous studies have shown that levels of MDMX and MDM2, oncogenic inhibitors of p53 tumor suppressor protein, are significantly elevated in PCa cells. Inhibition of MDM2 and MDMX using specific inhibitors has been shown to elevate the levels of p21, p27, and p53 in LNCaP (Lymph Node Carcinoma of the Prostate) cells leading to cell death. Recent studies have demonstrated that micro RNAs (miRNAs) play an important role in supporting the tumor suppressor function of p53 through regulating the balance between p53 and MDM2. In this regard, several miRNAs were found to be significantly altered to modulate the level and intracellular mechanisms of p53 and MDM2 in various cancers. OBJECTIVES: To determine the relative levels of miRNA31, miRNA-34a and miRNA-128 in LNCaP cells that were treated with NSC-207895 (MDMX inhibitor), SJ-172550 (MDMX inhibitor), and RG-7388 (MDM2 inhibitor). METHODS: LNCaP cells were treated with NSC-207895 (20 uM), SJ-172550 (20 uM) or RG-7388 (2 uM) for 24 hrs. After completing the treatments, the miRNAs were extracted from the LNCaP cells using the miRNeasy Tissue/Cells Advanced Kit from Qiagen. We analyzed the levels of miRNA-31, miRNA-34a, and miRNA-128 in the treated samples using qRT-PCR analysis method and compared the levels to the control. During the qRT-PCR analysis the cDNA was amplified using Meridian Biosciences qPCR Master Mix and specific primers for miRNAs from Origene were used according to the manufacturer's protocol. RESULTS: Our experimental results indicate that inhibition of MDMX using NSC-207895 and SJ-172550 can elevate the levels of p21, p27, and p53 leading to cell death. Determination of cell death markers in the past revealed induction of necroptosis following drug treatments. Our current results indicate measurable changes in the levels of miRNA-31 and miRNA-34a following inhibition of MDMX using SJ-172550. We are in the process of determining the possible link between the changes in the levels of miRNAs and cell death. ACKNOWLEDGEMENT: This research was supported by the Royal Dames of Cancer Research, Ft. Lauderdale, Florida. Citation Format: Rojin Fatirkhorani, Ahmed Saleh Alsarrani, Shyam Sundar Jaganathan, Umamaheswari Natarajan, Appu Rathinavelu. Micro RNA level changes in prostate cancer cells treated with MDMX and MDM2 inhibitors [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 5682.

Safety of Concomitant Cortical and Thalamic Stereoencephalography Explorations in Patients With Drug-Resistant Epilepsies.

Intracranial electrophysiology of thalamic nuclei has demonstrated involvement of thalamic areas in the propagation of seizures in focal drug-resistant epilepsy. Recent studies have argued that thalamus stereoencephalography (sEEG) may aid in understanding the epileptogenic zone and treatment options. However, the study of thalamic sEEG-associated hemorrhage incidence has not been investigated in a cohort study design. In this article, we present the largest retrospective cohort study of sEEG patients and compare hemorrhage rates between those with and without thalamic sEEG monitoring. Retrospective chart review of clinical and epilepsy history, electrode implantation, rationale, and outcomes was performed for 76 patients (age 20-69 years) with drug-resistant epilepsy who underwent sEEG monitoring at our institution (2019-2022). A subset of 38% of patients (n = 30) underwent thalamic monitoring of the anterior thalamic nucleus (n = 14), pulvinar nucleus (n = 25), or both (n = 10). Planned perisylvian orthogonal sEEG trajectories were extended to 2- to 3-cm intraparenchymally access thalamic area(s).The decision to incorporate thalamic monitoring was made by the multidisciplinary epilepsy team. Statistical comparison of hemorrhage rate, type, and severity between patients with and without thalamic sEEG monitoring was made. Our approach for thalamic monitoring was not associated with local intraparenchymal hemorrhage of thalamic areas or found along extended cortical trajectories, and symptomatic hemorrhage rates were greater for patients with thalamic coverage (10% vs 0%, P = .056), although this was not found to be significant. Importantly, patients with perisylvian electrode trajectories, with or without thalamic coverage, did not experience a higher incidence of hemorrhage (P = .34). sEEG of the thalamus is a safe and valuable tool that can be used to interrogate the efficacy of thalamic neuromodulation for drug-resistant epilepsy. While patients with thalamic sEEG did have higher incidence of hemorrhage at any monitoring site, this finding was apparently not related to the method of perisylvian implantation and did not involve any trajectories targeting the thalamus.

Abstract 5415: Fibroblast mediated head and neck tumor cell invasion in 3D culture is independent of partial epithelial to mesenchymal transition

Abstract Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with a five-year-survival of 61-64%. Recent studies have demonstrated tumor keratinocytes with features of a partial transition from epithelial to a mesenchymal phenotype, also known as partial-EMT (pEMT), at the edge of invading tumor islands associates with metastatic disease. As such, pEMT likely results from direct interactions between tumor cells and their surrounding microenvironment. To test if specific secreted factors or cell interactions drive the acquisition of pEMT, we first analyzed a series of primary and established HNSCC cell populations to determine TGF-β1 responsiveness since TGF-β1 is a known driver of pEMT. Of the eight populations tested, six displayed an increased level of pSMAD3 upon incubation with 5 ng/mL of TGF-β1 (p < 0.0001). To determine if this TGF-β1 response leads to an increase in pEMT phenotype, a pEMT-score (derived from mRNA expression of 9 pEMT markers) for each HNSCC population was determined following TGF-β1 treatment. As expected, the two non-responsive HNSCC populations showed no increase in pEMT-score, whilst five of the six TGF-β1-responsive HNSCC populations demonstrated a significant increase in pEMT-score (p = 0.006). To assess if TGF-β induced pEMT phenotype correlates with increased invasive potential, we produced 3D skin equivalent models using the eight HNSCC keratinocyte populations, in the presence or absence of primary fibroblasts and/or TGF-β1 treatment. TGF-β1 treatment alone caused a significant increase in invasion of all five TGF-β1-induced pEMT HNSCC populations (r2 = 0.449, p = 0.0045), whilst the three populations previously shown to be pEMT unresponsive to TGF-β1 treatment showed no increase. Interestingly, addition of primary fibroblasts without TGF-β1 treatment caused a universal dramatic increase in invasion in 3D organ culture (p = 0.0064, 34-fold increase), regardless of the previously determined TGF-β1-induced pEMT status. Unexpectedly, TGF-β1 treatment in the presence of fibroblasts caused no significant increase in invasion in 3D cultures (r2 = 0.00001, p = 0.9906). We next compared levels of pEMT markers in 3D cultures using immunofluorescence and observed a significant increase in PDPN in six of the eight HNSCC populations (p = 0.0136) with the addition of fibroblasts suggesting that factors independent of TGF-β1 contributes to pEMT marker expression and invasion in 3D culture. Overall, these data demonstrate fibroblasts induce HNSCC keratinocyte invasion regardless of the population’s ability to respond to TGF-β1-induced pEMT and that pEMT may be driven by factors independent of TGF-β1 in 3D culture. Citation Format: Pyung Hun Park, Michael M. Alexander, Joseph M. Curry, Adam J. Luginbuhl, Andrew P. South. Fibroblast mediated head and neck tumor cell invasion in 3D culture is independent of partial epithelial to mesenchymal transition [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 5415.

Abstract 3237: KDM1A/LSD1 inhibition enhances chemotherapy response in ovarian cancer

Abstract Background: Ovarian cancer (OCa) is the deadliest of all gynecological cancers. The standard treatment for OCa is platinum-based chemotherapy, such as carboplatin or cisplatin in combination with paclitaxel. Most patients are initially responsive to these treatments; however, nearly 90% will develop recurrence and inevitably succumb to chemotherapy-resistant disease. Recent studies have revealed that the epigenetic modifier lysine-specific histone demethylase (KDM1A/LSD1) is highly overexpressed in OCa. However, whether KDM1A plays a role in chemoresistance and whether its inhibition enhances chemotherapy response in OCa is unknown. In this study, we explored the hypothesis that KDM1A inhibition will sensitize OCa cells to standard-of-care chemotherapy. Methods: Transduction of KDM1A-specific shRNA was used to generate KDM1A knockdown (KD) cells. Cell viability, colony formation, and apoptosis assays were used to determine the impact of KDM1A KD on sensitization of SKOV3, OVCAR8, and OVCAR5 OCa cells to cisplatin, carboplatin, and paclitaxel. The combination effect of KDM1A inhibitors (NCD38 and SP2509) and chemotherapy drugs was further determined. Mechanistic studies were conducted using RNA-sequencing, RT-qPCR, and Western blotting. In vivo efficacy ofKDM1A knockdown with or without chemotherapy was determined using OCa orthotopic xenograft models. Results: Analysis of TCGA datasets revealed that KDM1A expression is negatively correlated with OCa survival, and its expression is high in patients who do not respond to chemotherapy. Further, Western blotting results show that treatment with chemotherapy drugs cisplatin, carboplatin, and paclitaxel increased KDM1A expression in OCa cells. KDM1A-KD or KDM1A inhibition sensitized OCa cells to chemotherapy drugs in reducing cell viability, survival, and enhancing apoptosis. Moreover, knockdown of KDM1A sensitized carboplatin-resistantA2780-CP70 cells to carboplatin treatment. RNA-seq studies revealed that KDM1A-KD and cisplatin-regulated genes showed negative correction with epithelial-mesenchymal transition (EMT) and positive correlation with apoptosis-related pathways. Importantly, KDM1A KD in combination with cisplatin significantly reduced the tumor growth in the orthotopic OCa xenograft model. Conclusion: These results suggest that the combination of KDM1A inhibitors with chemotherapy is a viable therapeutic approach for the treatment of OCa Citation Format: Jessica D. Johnson, Yihong Chen, Sridharan Jayamohan, Yi He, Diksha Jamwal, Neetesh Pandey, Edward Kost, Ratna K. Vadlamudi, Gangadhara R. Sareddy. KDM1A/LSD1 inhibition enhances chemotherapy response in 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 3237.

Abstract 6525: Modulating the immune response in cholangiocarcinoma: Targeting sulfatase-2 for therapeutic intervention

Abstract Cholangiocarcinoma (CCA) is an aggressive epithelial malignancy of the bile ducts. Recent reports have suggested a rise in the incidence of CCA globally. Current treatments for CCA have limited effectiveness, with only 20-30% response rates in patients with advanced cancer. Thus, there is a growing need to investigate new therapeutic targets for CCA. The tumor microenvironment (TME) is a potential target for novel therapies. The TME plays an important role in progression and metastasis of cancer through facilitating immune escape. Recent studies have demonstrated potential roles for heparan sulfate proteoglycans (HSPGs) in tumorigenesis. Sulfatase 2 (SULF2) is a heparan sulfate editing sulfatase that removes the 6-O sulfate moiety within the heparan sulfate (HS) chains and alters the affinity of HS chains for growth factors and cytokines and their receptors, thus modulating HSPG function in cell signaling pathways. HSPG specific sulfatases have been recently identified as a potential therapeutic target in CCA. We aimed to assess the effects of anti-Sulfatase-2 antibody on immune cells in the tumor microenvironment of syngeneic CCA xenografts in C57BL6 mice. Mice bearing syngeneic CCA xenografts were treated with an anti-sulf2 antibody, and the tumors compared to untreated control xenografts. After treatment, the tumors were harvested and analyzed by Cytometry by time of flight (Cytof) to identify changes in the types and numbers of immune cells in the tumor xenografts. Treatment with anti-sulf2 antibody resulted in a decrease in immunosuppressive cells such as tumor associated macrophages (TAMs) and myeloid derived suppressor cells (MDSC) compared to the control. There was also an increase in anti-tumor cells such as T-cells and NK cells, suggesting that suppressing sulf-2 in the microenvironment can shift the TME toward an anti-tumorigenic rather than a pro-tumorigenic environment. In summary, our work demonstrates the potential to target Sulfatase 2 as a therapeutic mechanism for immunomodulation of the tumor microenvironment. Future experiments to determine the relationship between specific clinical phenotypes and the number, activities and types of immune cells seen in the TME, and experiments in other hepatobiliary cancers models, such as hepatocellular carcinoma and gallbladder cancer, will be conducted. Citation Format: Tayla R. Brooks, Nellie Campbell, Melanie Keim, Lewis R. Roberts. Modulating the immune response in cholangiocarcinoma: Targeting sulfatase-2 for therapeutic intervention [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 6525.

Sestrin2 and Sestrin3 protect spermatogenesis against heat-induced meiotic defects.

Heat stress (HS) induces testicular oxidative stress, impairs spermatogenesis, and increases the risk of male infertility. Recent studies have highlighted the antioxidative properties of the Sestrins family in reducing cellular oxidative damage. However, the role of Sestrins (Sestrin1, 2, and 3) in the testicular response to heat stress remains unclear. Here, we found that Sestrin 2 and 3 were highly expressed in the testis relative to Sestrin1. Then, the Sestrin2-/- and Sestrin3-/- mice were generated by CRISPR/Cas9 to investigate the role of them on spermatogenesis after HS. Our data showed that Sestrin2-/- and Sestrin3-/- mice testes exhibited more severe damage manifested by exacerbated loss of germ cells and higher levels of oxidative stress as compared to wild-type counterparts after HS. Notably, Sestrin2-/- and Sestrin3-/- mice underwent a remarkable increase in heat-induced spermatocyte apoptosis than that of controls. Mechanistically, the transcriptome landscape of spermatocytes and chromosome spreading showed that loss of Sestrin2 and Sestrin3 exacerbated meiotic failure by compromising DNA double-strand breaks (DSBs) repair after heat stress. Taken together, our work demonstrated a critical protective function of Sestrin2 and Sestrin3 in mitigating the impairments of spermatogenesis against heat stress.

Abstract 7117: Convection enhanced delivery of a novel ATR inhibitor synergizes with systemic lomustine for improved treatment of glioblastoma

Abstract Developing effective strategies for treating glioblastoma (GBM), the most common and aggressive form of brain cancer, has been a long-standing challenge. Despite rigorous treatment regimens including surgical resection with concomitant radiotherapy and chemotherapy, the prognosis for this disease remains poor, largely due to tumor recurrence, resistance to conventional therapeutics, pharmacokinetic and brain delivery challenges, and dose-limiting toxicities of existing therapies. The DNA damage response and DNA repair mechanisms such as the ataxia telangiectasia and Rad3-related (ATR) pathway are key mediators of therapeutic responses, and recent studies have shown that targeting DNA repair proteins alongside standard-of-care options is a promising anti-tumor strategy. Here, we employ a combination approach using a next-generation macrocyclic ATR inhibitor, ATRIN-333, to sensitize GBM tumors to alkylators. We establish the potency of ATRIN-333 and report a robust synergistic interaction between it and the alkylator lomustine in GBM cell-based assays and in a murine flank tumor model. This combinatorial treatment was then applied to a mouse intracranial tumor model, where we utilized a convection enhanced delivery (CED) system combined with nanoparticle technology for direct intracranial administration of ATRIN-333. ATRIN-333 was successfully encapsulated into a novel polymeric nanoparticle formulation using poly(ethylene glycol)-co-poly(ethylene brassylate-co-dioxanone) (PEG-EB-co-DO). CED of both free and encapsulated ATRIN-333 potently sensitized intracranial GBM tumors to low-dose (5 mg/kg) systemically-delivered lomustine, reducing tumor size and conferring a substantial survival benefit compared to cohorts treated with lomustine or the ATR inhibitor alone. The combination approach was well tolerated by the mice, with no hematological toxicity observed as assessed by bone marrow analysis and blood cell counts. Our results demonstrate that ATR inhibitor/lomustine combination therapy, used in conjunction with a CED platform, is a powerful avenue for GBM treatment and a viable option for potential clinical implementation. Note: AJ and TL contributed equally to this work. Citation Format: Alexander Josowitz, Teresa Lee, Ranjini K. Sundaram, Jinal Pothupitiya, Eric J. Brown, Amrita Sule, Jason Beckta, Yongheng Wang, Joseph Vacca, Oren Gilad, Ranjit S. Bindra, W Mark Saltzman. Convection enhanced delivery of a novel ATR inhibitor synergizes with systemic lomustine for improved treatment of glioblastoma [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 7117.

Abstract 232: Multi-dimensional patient-derived organoid analysis highly correlates with progression-free survival of pancreatic cancer patients in a retrospective clinical trial

Abstract Patient-derived tumor organoids (PDOs) are promising cancer models, since they preserve the clonal heterogeneity, mutational landscape, and histological architecture of the originating patient tumor1-2. Recent studies have even provided first evidence that PDOs responded similarly to the corresponding patient when treated with the same standard of care therapy, but these studies were only able to predict clinical responses in a subset of patients3,4. This restriction was largely due to the limitation of current analysis methods. The gold-standard analysis method for PDO-based research, CellTiter-Glo 3D,5,6 fails to account for the heterogeneity of PDOs by relying on a bulk lysis approach, and thus only extracts a fraction of the clinically-relevant information that PDOs could provide7. Therefore, we hypothesized that using higher-dimensional analysis methods, will further unlock the predictive performance of PDOs and facilitate translation of research. In this study, we developed an artificial intelligence-driven analysis platform for live-PDO imaging. By combining drug screening metrics with dynamic quantification of organoids on a single-organoid resolution, we unraveled patient-specific tumor heterogeneity and PDAC aggressiveness in response to therapies8. Using a fully characterized a PDAC organoid panel (n=8) we matched our PDO analysis with retrospective clinical patient response to standard of care therapies (gemcitabine-paclitaxel and FOLFIRINOX). Our results demonstrated that our PDO analysis method identified patient-specific sensitives to therapy that were in-line with clinical outcomes. Moreover, our PDO readouts highly correlated with progression-free survival of matched patients (R=0.97), which was a significant improvement to the current, conventional drug response readouts. Taken together, our approach increased the clinical translatability of PDOs by more accurately recapitulating and measuring the complexity of human tumors. This work highlights the potential applications (extendable to other tumor types) and clinical translatability of our approach in drug discovery and clinical care, in the emerging era of personalized medicine.

Demystifying the likelihood of reidentification in neuroimaging data: A technical and regulatory analysis

Abstract Sharing research data has been widely promoted in the field of neuroimaging and has enhanced the rigor and reproducibility of neuroimaging studies. Yet the emergence of novel software tools and algorithms, such as face recognition, has raised concerns due to their potential to reidentify defaced neuroimaging data that are thought to have been deidentified. Despite the surge of privacy concerns, however, the risk of reidentification via these tools and algorithms has not yet been examined outside the limited settings for demonstration purposes. There is also a pressing need to carefully analyze regulatory implications of this new reidentification attack because concerns about the anonymity of data are the main reason that researchers think they are legally constrained from sharing their data. This study aims to tackle these gaps through rigorous technical and regulatory analyses. Using a simulation analysis, we first tested the generalizability of the matching accuracies in defaced neuroimaging data reported in a recent face recognition study (Schwarz et al., 2021). The results showed that the real-world likelihood of reidentification in defaced neuroimaging data via face recognition would be substantially lower than that reported in the previous studies. Next, by taking a US jurisdiction as a case study, we analyzed whether the novel reidentification threat posed by face recognition would place defaced neuroimaging data out of compliance under the current regulatory regime. Our analysis suggests that defaced neuroimaging data using existing tools would still meet the regulatory requirements for data deidentification. A brief comparison with the EU’s General Data Protection Regulation (GDPR) was also provided. Then, we examined the implication of NIH’s new Data Management and Sharing Policy on the current practice of neuroimaging data sharing based on the results of our simulation and regulatory analyses. Finally, we discussed future directions of open data sharing in neuroimaging.

Abstract 4995: Impact of radiotherapy on extracellular vesicle mediated anti-tumor immunity in oligometastatic prostate cancer

Abstract Metastasis-ablative radiotherapy is a new therapeutic approach that prolongs survival in patients with advanced cancers. Tumour irradiation can elicit an immunogenic cell death resulting in the expansion of tumour-reactive T cells and eradication of both irradiated and distant non-irradiated metastases, referred to as the “abscopal effect”. This abscopal response, nevertheless, is observed in a minority of patients suggesting uncharacterized mechanisms that prevent robust systemic anti-tumor immune response. Tumour-derived extracellular vesicles (TdEVs) have recently emerged as mediators of antitumor immunity but their immunomodulatory role in response to radiotherapy remains largely unknown. Recent clinical studies by our lab have demonstrated that circulating levels of tumour-derived extracellular vesicles (tdEVs) are elevated in response to radiotherapy and high tdEV concentrations are associated with reduced levels of peripheral cytotoxic CD8+ T cells and higher risk of disease recurrence in advanced prostate cancer. Based on our findings, we hypothesize that radiotherapy induces the release of tumor-derived EVs that suppress anti-tumor immunity. Prostate cancer cells (PC3 and DU145) were irradiated with clinically used doses of ionizing radiation (20Gy x 1 or 10Gy x 3 fractions) and tdEVs were co-cultured with human CD8+ T cells to measure their proliferation and cytotoxic activity. Increased levels of tdEVs were released by tumour cells treated with radiotherapy. A higher frequency of impaired T cell cytotoxic activity and a reduction in CD8 T cell proliferation was found in the 10Gy x 3 radiation regimen. Proteomic analysis and western blot showed an increased expression of the immune checkpoint molecule B7-H3 on the tumour cell surface and tdEVs in response to radiotherapy. While coculture of CD8 T cells with B7-H3 depleted tdEVs led to recovery of T-cell cytotoxic ability, overexpression of the B7-H3 in tdEVs inhibited cytotoxic activity. This study provides a rationale for future studies in which we will test the immune-mediated effects of radiotherapy-induced tdEVs in immunocompetent mouse models and investigate B7-H3 blockade as a therapeutic approach to boost abscopal response in the treatment of advanced prostate cancer. Citation Format: Chisom J. Uzendu, Yohan Kim, Roxane R. Lavoie, Haidong Dong, Sean Park, Fabrice Lucien-Matteoni. Impact of radiotherapy on extracellular vesicle mediated anti-tumor immunity in oligometastatic prostate 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 4995.

Abstract 4871: Colorectal cancer incidence and overall survival by race, stage, and age: A SEER database analysis, 2009-2020

Abstract Introduction: In the United States, colorectal cancer (CRC) is the fourth most common cancer and the second leading cause of cancer-related deaths. Although incidence rates of CRC have been decreasing overall, recent studies suggest a shift in demographics, specifically an increase in the number of new CRC cases among younger individuals and a higher incidence among those who identify as non-Hispanic Native American/Alaska Native. To examine the latest trends in incidence and overall survival (OS) among adults with CRC in the United States, we conducted an observational study using the Surveillance, Epidemiology, and End Results (SEER) Program database. Methods: Patients aged ≥18 years with newly diagnosed CRC between January 1, 2009, and December 31, 2020 were identified in the SEER 17 database. Age-adjusted incidence rates for CRC were calculated by race/ethnicity and age groups (18-49, 50-64, and ≥65 years) from 2009 to 2020. Kaplan-Meier curves were generated to examine 5-year OS by race/ethnicity, stage, and age groups. Results: There were 429,218 CRC cases identified with a median age of 67 years. Most were male (52.4%) with stage 0-II CRC (51.4%). Most patients identified as non-Hispanic White (66.3%), followed by non-Hispanic Black (11.5%), non-Hispanic Asian/Pacific Islander (8.9%), non-Hispanic Native American/Alaska Native (0.7%), and Hispanic of any race (12.7%). The age-adjusted incidence rate between 2009 and 2020 was 51.9 per 100,000 persons; incidence decreased from 59.5 per 100,000 persons in 2009 to 44.2 per 100,000 persons in 2020, with male patients having a higher incidence rate than female patients. By 2020, non-Hispanic Native American/Alaska Native patients had the highest incidence rate (54.5 per 100,000 persons) followed by non-Hispanic Black patients (50.6 per 100,000 persons). CRC incidence rates increased slightly for age <50 years (10.5 to 12.9 per 100,000 persons) and decreased for ages 50-64 (74.6 to 63.9 per 100,000 persons) and ≥65 years (222.4 to 136.1 per 100,000 persons). Non-Hispanic Black patients (53%), age ≥65 years (47%), and those with stage III-IV CRC (41%) had a lower 5-year OS from 2015 to 2019 compared to patients who were non-Hispanic White (57%), aged 50-64 (68%) and <50 years (70%), and with stage 0-II CRC (77%). Conclusion: Our results confirm a slight increase in CRC incidence among younger (<50 years) individuals over the 2009-2020 time period. Patients who were non-Hispanic Native American/Alaska Native had the highest CRC incidence rate and patients who were non-Hispanic Black had the poorest OS. Targeted preventative efforts such as CRC screening programs in addition to improved access to care/treatment may be needed to reduce the number of new cases and improve outcomes among historically underserved groups. Citation Format: Alicia C. McDonald, Seongjung Joo, Jiemin Ma, Mayur M. Amonkar, Changxia Shao, Kaushal Desai, Anne C. Deitz. Colorectal cancer incidence and overall survival by race, stage, and age: A SEER database analysis, 2009-2020 [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 4871.