Target In Cancer Research Articles

Simultaneous targeting and suppression of heat shock protein 60 to overcome heat resistance and induce mitochondrial death of tumor cells in photothermal immunotherapy

As the most aggressive and metastatic subtype of breast cancer, clinical demands of triple negative breast cancer (TNBC) have far not been met. Heat shock protein 60 (HSP60) is over expressed in tumor cells and impair the efficacy of photothermal therapy. In this work, a conjugate composed of self-designed peptide targeting HSP60 and gold nanorods was constructed, referred to as AuNR-P17. Results showed that AuNR-P17 was able to simultaneously down regulate the level of HSP60 and locate in the mitochondria where HSP60 is enriched in the tumor cells of TNBC, which also impeded the interaction between HSP60 and integrin α3, thereby reducing the tumor cells' heat tolerance and metastatic capabilities. At the same time, AuNR-P17 induced remarkable mitochondrial apoptosis when exposed to the laser irradiation of 808 nm. The dual functions of AuNR-P17 led to the decrement of BCL-2 and the activation of p53 and cleaved caspase-3. The danger associated molecular patterns (DAMPs) generated from the mitochondrial apoptosis elicited strong and long-term specific immune responses against TNBC in vivo and ultimately inhibited the tumor metastasis and recurrence with significantly prolonged survival (>100 days) on TNBC mice. In conclusion, this study demonstrated HSP60 a promising potential therapeutic target for triple negative breast cancer and exhibited powerful capacity of AuNR-P17 in photothermal immune therapy.

The use of SP/Neurokinin-1 as a Therapeutic Target in Colon and Rectal Cancer.

Different studies have highlighted the role of Substance P / Neurokinin 1 Receptor (SP/NK-1R) axis in multiple hallmarks of cancer including cell transformation, proliferation, and migration as well as angiogenesis and metastasis of a wide range of solid tumors including colorectal cancer. Until now, the selective high-affinity antagonist of human SP/NK1-R aprepitant (Emend) has been authorized by the Food and Drug Administration as a low dosage medication to manage and treat chemotherapy-induced nausea. However, increasing evidence in recent years support the potential utility of high doses of aprepitant as an antitumor agent and thus, opening the possibility to the pharmacological repositioning of SP/NK1-R antagonists as an adjuvant therapy to conventional cancer treatments. In this review, we summarize current knowledge on the molecular basis of colorectal cancer as well as the pathophysiological importance of SP/NK1-R and the potential utility of SP/NK-1R axis as a therapeutic target in this malignancy.

Deciphering the cellular landscape and potential targets of nasopharyngeal and oral cancers using single-cell RNA sequencing.

Cellular heterogeneity in nasopharyngeal cancer (NPC) and oral cancer remains unclear. In the current study, using single-cell RNA sequencing techniques, we investigated the cellular landscape in NPC and oral cancers. We identified a diverse range of cell types within the tumor microenvironment (TME) and variations in cell infiltration between NPC and oral cancer. In oral cancer, we observed a predominant infiltration of epithelial cells, fibroblasts, and endothelial cells (ECs), while T cells were the main infiltrating cell population in NPCs. We further classified these infiltrating cells into subclusters. Additionally, we observed complex interactions among cells that led to distinct trajectories. In particular, a unique epithelial subcluster with high expression of major histocompatibility complex class II (MHC-II) molecules was correlated with a favorable outcome and infiltration of CD4+ T cells. In addition, MHC-II+ epithelial cells inhibited mouse tumor growth and promoted T-cell infiltration. Consequently, our findings provide a deep understanding of the TME showing a significant prognostic value and therapeutic potential.

AI-Assisted Generation and In-depth In-silico Evaluation of Potential Inhibitor Targeting Aurora Kinase A (AURKA): An Anticancer Discovery Exploiting Synthetic Lethality Approach

Genetic alterations are lead causative agents behind the complex pathologies of cancers which render all treatments unarmed. Such alterations in oncogenes can be treated by direct inhibition by specific drugs while alteration in tumor suppressor genes mediating loss of function is challenging to treat. Identification of synthetic lethal partners to specific tumor suppressor genes and mediating their inhibition can be a potential approach to deal with loss of function mutations. Aurora kinase A (AURKA) has been established as an effective synthetic lethal partner of several tumor suppressor genes and is overexpressed in cancerous conditions, mediating adverse pathologies. The present AI-assisted study deals with the generation of novel inhibitor compounds against AURKA and the exhaustive evaluation of the best compound using molecular docking, molecular dynamic simulation, MM/PBSA, and QM/MMGBSA-based analysis. Out of the 200 novel compounds generated using features of ATP binding pocket of AURKA and previously reported inhibitor, compound 1 (4-{5-fluoro-6-[(1Z)-3-hydrazinyl-3-oxo-2-phenylprop-1-en-1-yl]pyridin-2-yl}benzoic acid) was identified as the most potent candidate with high negative binding energy of -10.4 kcal/mol in molecular docking analysis. The molecular dynamic simulation analysis of the AURKA-compound 1 complex and the apo-AURKA protein resulted in major conformational changes in the conserved DFG motif and loop 277-291 of AURKA in the AURKA-compound 1 complex thus inhibiting the entry of ATP to its binding site. The free energy landscape displayed a persistence of folded states of the enzyme in complex form. The MM/PBSA revealed effective Gibb’s free energy of binding of -11 kcal/mol for compound 1 inhibiting AURKA. The QM/MMGBSA analysis resulted in a significantly high negative binding energy of -13.98 kcal/mol proving significant inhibition potential of compound 1 against AURKA. Therefore, further in-vitro investigation can provide a novel effective, and safe treatment against a wide range of cancers by targeting a well-established cancer target AURKA.

Development of new LSM-83177 analogues as anti-tumor agents against colorectal cancer targeting p53-MDM2 interaction

LSM-83177, a phenoxy acetic acid derivative, is a small molecule reported for its promising anti-tumor properties. Via inhibiting the interaction between MDM2 and p53, LSM-83177 can elevate the active p53 levels within cells, thereby promoting apoptosis and inhibiting tumor growth. Also, LSM-83177 has been shown to inhibit GST activity in colorectal cancer HT29 cells. In the current work, novel LSM-83177 hydrazone analogs 5a-f, 7a-b, 10a-e, and 13a-b have been designed according to the structure features of LSM-83177 and their binding mode in the active site of MDM2. The anti-cancer activity of the newly synthesized analogs is evaluated against the HT29 cell line. The most potent compounds, 7a and 10a, showed IC50 = 12.48 and 10.44 µg/ml, respectively, when compared with Cisplatin (IC50 = 11.32 µg/ml) as a reference drug. Compounds 7a and 10a were introduced for further inspection for p53-MDM2 protein–protein interaction, where they displayed IC50 values of 3.65 and 11.08 µg/ml, respectively. Furthermore, hydrazones 7a and 10a increased the p-53 expression levels by 3.22– and 4.25-fold, respectively; in addition, they effectively reduced the GST expression levels in HT29 cancer cells with 0.56- and 0.30-fold increments in comparison to the untreated control.

An in-silico approach to target Breast cancer with novel phytochemicals

Aging leads to the manifestation of various diseases. Cancer being one of the major illness that is associated with the age. Breast cancer is still a relatively global health concern as the leading cancer cause of death among women. The current study also utilizes an in-silico approach to discover and characterize new phytochemicals as potential therapeutic agents to breast cancer. Here, we explore the molecular basis driving the makeup of breast cancer, with an emphasis on the PI3K/AKT/mTOR pathway, a well-known signaling cascade implicated in cell growth and therapy response. Two candidates (Thalidasine (-8.80 Kcal/mol) and 7-Epiclusianone (-8.62 Kcal/mol)) were found to be promising leads displaying high binding affinity and therapeutic potential through screening a diverse library of phytochemicals against key breast cancer target proteins. These phytochemicals exhibit diverse antineoplastic effects as cell proliferation, angiogenesis, and metastasis inhibitors, and/or as inducers of apoptosis. Besides, their ability to specifically target breast cancer stem cells and to increase sensitivity to traditional therapies make them an appealing option for breast cancer adjuvant therapy. Taken together our data suggest that these phytochemicals should be further studied alone and in novel nano formulations that enhance bioavailability and reduce toxicity. This study adds to the evidence for the potential role of natural products in breast cancer and the role of lifestyle in cancer prevention.

Oxidative Stress and Cancer Therapy: Controlling Cancer Cells Using Reactive Oxygen Species

Cancer is a multifaceted disease influenced by various mechanisms, including the generation of reactive oxygen species (ROS), which have a paradoxical role in both promoting cancer progression and serving as targets for therapeutic interventions. At low concentrations, ROS serve as signaling agents that enhance cancer cell proliferation, migration, and resistance to drugs. However, at elevated levels, ROS induce oxidative stress, causing damage to biomolecules and leading to cell death. Cancer cells have developed mechanisms to manage ROS levels, including activating pathways such as NRF2, NF-κB, and PI3K/Akt. This review explores the relationship between ROS and cancer, focusing on cell death mechanisms like apoptosis, ferroptosis, and autophagy, highlighting the potential therapeutic strategies that exploit ROS to target cancer cells.

Abstract B009: Characterization and CRISPR perturbation of cancer-associated fibroblast heterogeneity in vitro models

Abstract Cancer-associated fibroblasts (CAFs) are attractive therapeutic targets for cancer due to their abundance in the tumor microenvironment (TME) and extensive pro- and antitumorigenic functions. However, formulating CAF-targeting strategies remains challenging due to the complexity of CAF biology. CAFs specialize into phenotypically and functionally distinct subtypes that may respond differently to specific treatments. Thus, designing CAF-targeting therapies necessitates a thorough understanding of CAF heterogeneity and preclinical model systems that can reliably prototype CAF biology observed in tumors. However, CAF heterogeneity is still not well-understood for many solid tumors, including the stroma-rich pancreatic ductal adenocarcinoma (PDAC), and the translatability of stroma models has not been comprehensively evaluated. In this work, we developed in vitro cell lines of tumor-CAF cocultures using primary CAFs derived from PDAC and used single-cell transcriptomics and CRISPR perturbation to investigate CAF heterogeneity and subtype-specific responses. We found that coculturing primary CAFs with the BxPC3 PDAC cell line could capture the tumor-CAF crosstalks underlying CAF activation. We characterized eight subtypes, including myofibroblastic, inflammatory, extracellular matrix (ECM)-like, and interferon CAFs, which could be preserved with immortalization. We also delineated the trajectories of CAF subtype interconvertibility, highlighting inflammatory CAFs as the likely initial diseased state and ECM CAFs as a “reservoir” that seeded the later states. By correlating the in vitro subtypes with clinical data of immunotherapy responses, we established that the in vitro cell lines could model the immuno-modulatory and immunoresistant phenotypes of CAFs. Finally, using an immortalized tumor-CAF coculture line, we performed Perturb-seq single-cell perturbation to perturb several stroma genes of interest, including TGFBR1, SPATS2L, AEBP1, and PTGS1, and evaluated the subtype-specific effects of the perturbations. We found that perturbing TGFBR1 resulted in the expected eradication of myofibroblastic CAFs, while the other perturbations resulted in subtype-specific modulations of metabolic and extracellular matrix related pathways. Overall, our findings underscored that in vitro tumor-CAF coculture models could serve as a translatable system that effectively captured CAF biology and heterogeneity observed in tumors and highlighted some similarities between PDAC CAFs and previously characterized breast cancer CAFs. We also demonstrated that single-cell perturbation could be a useful approach for interrogating the distinct responses of different CAF subtypes to perturbations. Citation Format: Elysia Saputra, Shamsudheen Karuthedath Vellarikkal, Lixia Li, Hong Sun, Suchitra Natarajan, Federica Piccioni, Alex M. Tamburino, Xin Yu, Aleksandra K. Olow. Characterization and CRISPR perturbation of cancer-associated fibroblast heterogeneity in vitro models [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B009.

Parallel Analyses by Mass Spectrometry (MS) and Reverse Phase Protein Array (RPPA) Reveal Complementary Proteomic Profiles in Triple-Negative Breast Cancer (TNBC) Patient Tissues and Cell Cultures.

High-plex proteomic technologies have made substantial contributions to mechanism studies and biomarker discovery in complex diseases, particularly cancer. Despite technological advancements, inherent limitations in individual proteomic approaches persist, impeding the achievement of comprehensive quantitative insights into the proteome. In this study, we employed two widely used proteomic technologies, mass spectrometry (MS) and reverse phase protein array (RPPA) to analyze identical samples, aiming to systematically assess the outcomes and performance of the different technologies. Additionally, we sought to establish an integrated workflow by combining these two proteomic approaches to augment the coverage of protein targets for discovery purposes. We used 14 fresh frozen tissue samples from triple-negative breast cancer (TNBC: seven tumors versus seven adjacent non-cancerous tissues) and cell line samples to evaluate both technologies and implement this dual-proteomic strategy. Using a single-step protein denaturation and extraction protocol, protein samples were subjected to reverse-phase liquid chromatography (LC) followed by electrospray ionization (ESI)-mediated MS/MS for proteomic profiling. Concurrently, identical sample aliquots were analyzed by RPPA for profiling of over 300 proteins and phosphoproteins that are in key signaling pathways or druggable targets in cancer. Both proteomic methods demonstrated the expected ability to differentiate samples by groups, revealing distinct proteomic patterns under various experimental conditions, albeit with minimal overlap in identified targets. Mechanism-based analysis uncovered divergent biological processes identified with the two proteomic technologies, capitalizing on their complementary exploratory potential.

Senescence as a therapeutic target in cancer and age-related diseases.

Cellular senescence is a stress response that restrains the growth of aged, damaged or abnormal cells. Thus, senescence has a crucial role in development, tissue maintenance and cancer prevention. However, lingering senescent cells fuel chronic inflammation through the acquisition of a senescence-associated secretory phenotype (SASP), which contributes to cancer and age-related tissue dysfunction. Recent progress in understanding senescence has spurred interest in the development of approaches to target senescent cells, known as senotherapies. In this Review, we evaluate the status of various types of senotherapies, including senolytics that eliminate senescent cells, senomorphics that suppress the SASP, interventions that mitigate senescence and strategies that harness the immune system to clear senescent cells. We also summarize how these approaches can be combined with cancer therapies, and we discuss the challenges and opportunities in moving senotherapies into clinical practice. Such therapies have the potential to address root causes of age-related diseases and thus open new avenues for preventive therapies and treating multimorbidities.

High Expression of GABAA Receptor β Subunit Genes Is Associated with Longer Overall Survival in Medulloblastoma

Background/Objectives: Most of the rapid inhibitory neurotransmission in the brain is mediated through activation of the γ-aminobutyric acid (GABA) type A (GABAA) receptor, which is a ligand-gated ion channel. GABAA receptor activation via GABA binding allows for an intracellular influx of Cl− ions, thus inducing cellular hyperpolarization. Each GABAA receptor consists of a combination of five subunits, and several subunits have been proposed as biomarkers and therapeutic targets in cancer. Here, we show the expression of genes encoding β subunits of the GABAA receptor, namely GABRB1, GABRB2, and GABRB3, across the four different molecular subgroups of medulloblastoma (MB), which is the most common malignant pediatric brain tumor. We also show the associations of GABAA receptor β subunits with MB patients’ overall survival (OS). Methods: The expression of genes encoding GABAA receptor β subunits was analyzed using a previously described dataset comprising 763 MB tumor samples. Patients were classified into high- and low-gene-expression groups, and the Kaplan–Meier estimate was used to examine the relationship between gene expression levels and patient OS. Results: High GABRB1 expression was associated with better OS within each of the four molecular subgroups. The GABRB2 gene showed higher transcript levels in Group 3 MB compared to all other subgroups, and high expression was associated with better prognosis in Group 3 tumors. GABRB3 expression was significantly higher in Group 3 and Group 4 MB, and high expression of GABRB3 genes was associated with longer OS in the sonic hedgehog (SHH) subgroup. The high expression of GABRB1, GABRB2, and GABRB3 is associated with longer patient OS in a subgroup-specific manner. Conclusions: These results indicate a role for GABAA receptors containing β subunits in influencing MB progression.

Genetic variation perspective reveals potential drug targets for subtypes of endometrial cancer.

The study aims to identify potential drug targets for endometrial cancer (EC) subtypes through a Mendelian randomization (MR) approach, assessing their clinical relevance. We utilized genetic instruments for 4,907 plasma proteins from the deCODE Genetics study dataset, and data with EC (n = 12,906) from a genome-wide study (GWAS) meta-analysis in European populations for MR analyses. Complementary analyses included protein-protein interactions (PPI) network analysis, therapeutic efficacy evaluation, differential gene expression assessment, and prognosis evaluation. The expression levels of key drug targets were quantitatively measured at both the transcriptional and translational stages utilizing reverse transcription quantitative PCR (RT-qPCR) and immunohistochemistry (IHC). Additionally, we analyzed various clinicopathological features. Five drug targets for EC (CBR3, GSTO1, HHIP, IGF2R, and MMP10), seven for endometrioid subtypes (ACAP2, CBR3, GSTO1, HHIP, IGF2R, MMP10, and TLR2), and seven for non-endometrioid subtypes (CST3, DNAJB14, FSTL5, GMPR2, IFI16, MAPK9, and NEO1) were identified. Among these, IGF2R (OR = 1.165; 95% CI 1.067-1.272; p = 1.046 × 10- 2) and CST3 (OR = 0.523; 95% CI 0.339-0.804; p = 7.010 × 10- 3) were highlighted as key drug targets with causal evidence both at transcriptional and translational levels. This study preliminarily confirms that IGF2R and CST3 may serve as novel targets for the treatment of EC, providing a foundational reference for innovative clinical approaches to this disease.

Clinical advances and challenges in targeting FGF/FGFR signaling in lung cancer.

Fibroblast growth factors (FGFs) and their receptors regulate numerous cellular processes, such as metabolism and signal transduction, but can also drive tumorigenesis. Specifically, in lung cancer, the overexpression of FGFs, as well as the amplification, mutation and fusion of FGFR genes, are closely linked to the initiation, progression and resistance of the disease, suggesting that targeting FGF/FGFR is an attractive therapeutic strategy for lung cancer treatment. Nintedanib, a multitarget tyrosine kinase inhibitor (TKI) used in combination with docetaxel, has shown some success as a second-line therapy for lung cancer. However, clinical trials evaluating other FGFR inhibitors have yielded mixed results, indicating substantial complexity in targeting aberrant FGF/FGFR signaling. In this review, we describe the aberrations in FGF/FGFR signaling in lung cancer and summarize the clinical efficacy of FGFR inhibitors, such as multitarget TKIs, selective FGFR-TKIs and biological agents. We also discuss various challenges associated with FGFR targeting in lung cancer, including precision patient selection, toxicity and resistance. Finally, we provide perspectives on future directions, namely, developing novel FGFR-targeting drugs, such as FGFR degraders and more specific FGFR-TKIs, adopting combination therapy and targeting FGFs.

New Therapeutic Targets in RAS Wild-type Pancreatic Cancer.

The landscape of treatment of advanced PDAC is witnessing significant changes. This is in part due to the advent of molecular profiling, which has highlighted molecularly-distinct subsets of pts, especially those with KRAS wild-type disease. We now know that these pts harbor genomic alterations that not only serve as molecular drivers but also pose as therapeutically relevant markers. In the absence of strong evidence to support the use of targeted therapy in the front-line setting, we continue to offer chemotherapy for treatment-naïve pts. However, an argument can be made for the front-line use of targeted therapy in pts who are not fit for chemotherapy or who are not interested in it. The challenge is ensuring that molecular profiling is done in a timely fashion to prevent significant delays in therapy. In our practice, we offer molecular testing to all pts with a new diagnosis of advanced PDAC. We prefer the utility of targeted therapy in the second line and beyond for pts who have an actionable target, over the use of further chemotherapy, as targeted therapy appears to confer deep and durable responses and longer survival. For pts with MSI-H or MMRd disease, the use of immunotherapy is indicated, although it has to be noted that MSI-H/MMRd PDAC performed worse that other MSI-H/MMRd cancers treated with immunotherapy. Therefore, in the presence of MSI-H/MMRd and an additional actionable target, we prefer treating with targeted therapy and reserving immunotherapy for later lines. Pt preference has to be taken into consideration at all times though.

Acute Kidney Injury Following CAR-T Cell Therapy: A Nephrologist Perspective

Abstract Chimeric antigen receptor T-cell (CAR-T cell) therapy, an emerging personalized immunotherapy for various hematologic malignancies, autoimmune diseases, and other conditions, involves the modification of patients’ T cells to express a chimeric antigen receptor which recognizes tumor or autoimmune cell antigens. Thereby CAR-T cells destroy cancerous and other target cells selectively. Despite remarkable clinical improvements in patients, multiple adverse effects have been associated with CAR-T cell therapy. Among the most recognized adverse effects are cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, and tumor lysis syndrome. Even though less recognized, the incidence of acute kidney injury (AKI) ranges from 5% to 33%. The wide range of reported AKI incidence rates might depend on patient population characteristics and comorbidities and specific CAR-T cell therapy features. Even though the exact pathophysiology remains unknown, several key mechanisms including cytokine release syndrome, tumor lysis syndrome, and other factors such as direct renal toxicity of CAR-T cell therapy, conditioning regimens or other medications (e.g. antibiotics), and infectious complications (e.g. sepsis) have been proposed. Risk factors for CAR-T-related AKI include lower baseline glomerular filtration rate, higher rates of allopurinol or rasburicase use, intravenous contrast material exposure, elevated baseline lactate dehydrogenase, and grade 3 or higher cytokine release syndrome. Future prospective studies with larger patient populations are needed to gain more insight regarding the pathophysiology of CAR-T-related AKI, and, more importantly, to be able to prevent as well as to develop novel and more efficient treatment modalities. In this narrative review, we discuss the underlying pathophysiology, risk factors, potential interventions, and future directions related to AKI following CAR-T cell therapy.

Abstract B008: Exploring the Dual Roles of RNAs as Oncogenic Drivers and Therapeutic Targets in Cancer: A Cross-Sectional Study

Abstract RNAs have emerged as pivotal molecules in the complex landscape of cancer biology, acting as both drivers of oncogenesis and therapeutic targets. This cross-sectional experimental design research explores the dual roles of RNAs, particularly focusing on the interplay between non-coding RNAs (ncRNAs), messenger RNAs (mRNAs), and their regulatory networks in various cancer types. The study systematically analyzes RNA expression profiles across a broad spectrum of cancer samples, employing high-throughput sequencing technologies combined with bioinformatics tools to identify key RNA species that contribute to tumorigenesis. The experimental design includes the collection of tumor and adjacent normal tissues from patients diagnosed with breast, lung, and colorectal cancers. RNA extraction and sequencing are performed to generate comprehensive expression profiles. Differential expression analysis is conducted to pinpoint RNAs that are significantly dysregulated in cancerous tissues compared to their normal counterparts. Subsequently, functional assays, including RNA interference (RNAi) and CRISPR/Cas9-mediated gene editing, are utilized to validate the oncogenic or tumor-suppressive roles of these RNAs in cancer cell lines. To further elucidate the mechanistic pathways, the study integrates data from RNA-binding protein immunoprecipitation (RIP) and crosslinking immunoprecipitation (CLIP) assays, providing insights into the RNA-protein interactions that influence cancer progression. Additionally, the research evaluates the therapeutic potential of targeting these RNAs, using small interfering RNAs (siRNAs) and antisense oligonucleotides (ASOs) in preclinical cancer models. Preliminary findings highlight the significance of long non-coding RNAs (lncRNAs) and micro RNAs (miRNAs) in modulating key signaling pathways involved in cell proliferation, apoptosis, and metastasis. This study underscores the importance of RNA-based diagnostics and therapeutics, paving the way for innovative treatment strategies in cancer management. Citation Format: Fathelrahman M Gameel. Exploring the Dual Roles of RNAs as Oncogenic Drivers and Therapeutic Targets in Cancer: A Cross-Sectional Study [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr B008.

Abstract I002: Alternative polyadenylation as a therapeutic target in cancer

Abstract Alternative polyadenylation (APA) is markedly dysregulated across cancer types. Although this phenomenon is well established and associated with altered patient prognosis, the functional importance of most dysregulated polyadenylation to cancer phenotypes remains unknown, as does the potential therapeutic impact of dysregulated APA. Recent work by our lab and others to address this gap has systematically identified specific APA events that alter key tumor phenotypes, including malignant cell growth and tumor recognition by cytotoxic T cells. Motivated by these studies, we sought to identify small molecules that modulate APA for therapeutic intent. We created a sensitive reporter of APA and used this reporter to conduct a molecular phenotypic reporter screen for APA-altering compounds. This screen revealed a diversity of compounds that altered APA transcriptome-wide. Phenotypic characterization of the strongest hit emerging from this screen revealed that it strongly induced cell differentiation and death of myeloid leukemia cells, with negligible toxicity for normal hematopoietic stem cells. Overall, these results highlight the untapped but promising therapeutic potential of targeting APA in cancer. Citation Format: Toshihiro Banjo, Satoshi Kaito, Austin M Gabel, Omar Abdel-Wahab, Robert K Bradley. Alternative polyadenylation as a therapeutic target in cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr I002.

Abstract A025: RNA-Based Therapeutics to target the p53 pathway in high-grade serous ovarian cancer: TAp63-Regulated Oncogenic LncRNAs (TROLLs) as novel therapeutic targets in cancer

Abstract High-grade serous ovarian cancer (HGSOC) is the most common and malignant type of ovarian cancer with a high frequency of p53 mutation and hyperactivation of the AKT pathway. Even though roughly 85% of patients achieve remission after initial surgical debulking and chemotherapy, four out of five HGSOC patients will experience disease recurrence, resulting in a 5-year survival rate of 43%. We have identified and characterized two TAp63 Regulated Oncogenic Long non-coding RNAs (TROLL-2 and TROLL-3) whose transcription is induced by mutant p53 and high expression level correlate with a more aggressive ovarian cancer grade and phosphorylation of AKT. In-depth analysis demonstrated that TROLL-2 and TROLL-3 directly activate AKT in tumor cells, thus linking p53 alterations to AKT activity. The use of AKT inhibitors in the clinic is limited because of frequent adverse effects, likely due to the constitutive expression of AKT in all cells. TROLL-2 and TROLL-3 expression is limited to tumor cells and provides a more specific target for decreasing AKT activation, potentially minimizing off-target effects. We have optimized reduction of TROLL-2 and TROLL-3 expression using antisense oligonucleotides (ASOs) in an ex vivo perfusion platform for 3D culture of microtumors from primary patient derived tumors. Samples show maximum reduction of proliferation (EdU) and phosphorylation of AKT when TROLL-2 and TROLL-3 ASOs are used concurrently. We also performed phospho-proteomics and single cell RNAseq to compare individual ASO-mediated knockdown of each lncRNA to combined targeted ASO treatments. We have developed primary patient derived xenograft models using ovarian tumors orthotopically implanted into NSG mice generating a relevant preclinical model to determine the efficacy of ASO treatment. To reduce the rapid degradation and clearance of ASOs in circulation, ASOs were encapsulated into lipid nanoparticles and metal-organic frameworks (MOFs) and we are currently testing these in vivo. Since AKT activation is associated with increased staging and resistance to platinum and targeted therapies in ovarian cancer patients, our data provides preclinical rationale for the implementation of ASOs and the use of new delivery methods as a relevant translational therapy and novel method to exploit the specificity of TROLL-2 and TROLL-3 expression in HGSOC. Citation Format: Ashley Lui, Marco Napoli, Jaden R Baldwin, Christina L Carr, Angie Rivera, Duy Nguyen, W. Gregory Sawyer, Michael R Dunne, Erin George, Omar K Farha, Michelle Teplensky, Elsa R Flores. RNA-Based Therapeutics to target the p53 pathway in high-grade serous ovarian cancer: TAp63-Regulated Oncogenic LncRNAs (TROLLs) as novel therapeutic targets in cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr A025.

Abstract B004: Ovarian cancer long intergenic noncoding RNA 1 is a potential therapeutic target in advanced ovarian cancer by promoting glycolytic pathway and hypoxic response

Abstract Ovarian cancer (OvC) is often diagnosed as an advanced disease because symptoms do not develop at earlier stages. Besides current treatments, alternative efficient therapies for OvC need to be established. We have previously identified that a novel long intergenic noncoding RNA (lincRNA) originated from chromosome 10q21 was predominantly expressed in clinical ovarian cancer tissues, designated as ovarian cancer lincRNA 1 (OIN1). Silencing of OIN1 in OvC cell lines substantially exhibited the inhibition of in vitro and in vivo cell proliferation, by upregulating apoptosis-related genes. In the present study, we aimed to evaluate whether OIN1 can be a therapeutic target in advanced OvC and how OIN1 drives the progression of OvC. We established long-term culturable spheroid cultures of OvC patient-derived cells (OvC-PDCs) from ascites of OvC patients as an advanced OvC model. The OvC-PDC spheroid cultures abundantly expressed OIN1 and stemness-related genes. OIN1-targeted siRNAs could suppress the spheroid growth and upregulate apoptosis-related genes such as RASSF5 and ADORA1 in OvC-PDC cultures. In a bloody ascites-generating xenograft in vivo model of mice intraperitoneally injected with OvC-PDC, OIN1-targeted siRNA treatment engineered by drug delivery system alleviated ascites production and prolonged the mice survival time. Based on transcriptomic analysis of OIN1 silencing in OvC-PDC cultures, we found that OIN1 inhibition exerts the downregulation of genes involved in glycolytic pathway and hypoxic response. We further demonstrated that OIN1 modulates HIF1a-mediated transcriptional regulation in OvC- PDCs. The present findings provide promising evidence that OIN1 can be a potential therapeutic target for advanced OvC. Citation Format: Kuniko Horie, Wataru Sato, Kazuhiro Ikeda, Satoshi Inoue. Ovarian cancer long intergenic noncoding RNA 1 is a potential therapeutic target in advanced ovarian cancer by promoting glycolytic pathway and hypoxic response [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr B004.

Chimeric SFT2D2-TBX19 Promotes Prostate Cancer Progression by Encoding TBX19-202 Protein and Stabilizing Mitochondrial ATP Synthase through ATP5F1A Phosphorylation.

Specific chimeric RNAs and their products are consistently regarded as ideal tumor diagnostic markers and therapeutic targets. Chimeric RNAs can mediate tumor cell plasticity, neuroendocrine processes, polarization of tumor-associated macrophages, and resistance to chemotherapy and immunotherapy. However, the discovery of chimeric RNAs in prostate cancer is still in its early stages. This study identifies the chimeric SFT2D2-TBX19 as a novel transcript encoding the TBX19-202 protein. Both TBX19-202 and its parental TBX19, which share homologous amino acid sequences, enhance prostate cancer cell proliferation, migration, and invasion. Additionally, SFT2D2-TBX19 also functions as a lncRNA, interacting with the ATP synthase F1 subunit ATP5F1A, thereby increasing ATP5F1A phosphorylation mediated by TNK2/ACK1, which stabilizes the interaction between ATP5F1A and ATP5F1B. The region spanning 1801-2400bp of SFT2D2-TBX19 and the intermediate structural domain of ATP5F1A are crucial functional areas. This stabilization of ATP5F1A and ATP5F1B enhances mitochondrial ATP synthase activity and ATP production. Even under conditions of mitochondrial vulnerability, SFT2D2-TBX19 protects mitochondrial structural stability to maintain prostate cancer cell proliferation. This research provides comprehensive evidence that chimeric SFT2D2-TBX19 promotes prostate cancer progression by encoding the TBX19-202 protein and stabilizing mitochondrial ATP synthase via ATP5F1A phosphorylation. These findings highlight SFT2D2-TBX19 as a potential therapeutic target for prostate cancer.