Effective Cancer Therapeutics Research Articles

Pan-Cancer Drug Sensitivity Prediction from Gene Expression using Deep Learning.

Cancer is a group of complex diseases, with tumor heterogeneity, durable drug efficacy, emerging resistance, and host toxicity presenting major challenges to the development of effective cancer therapeutics. While traditionally used methods have remained limited in their capacity to overcome these challenges in cancer drug development, efforts have been made in recent years toward applying "big data" to cancer research and precision oncology. By curating, standardizing, and integrating data from various databases, we developed deep learning architectures that use perturbation and baseline transcriptional signatures to predict efficacious small molecule compounds and genetic dependencies in cancer. A series of internal validations followed by prospective validation in prostate cancer cell lines were performed to ensure consistent performance and model applicability. We report SensitivitySeq, a novel bioinformatics tool for prioritizing small molecule compounds and gene dependencies in silico to drive the development of targeted therapies for cancer. To the best of our knowledge, this is the first supervised deep learning approach, validated in vitro, to predict drug sensitivity using baseline cancer cell line gene expression alongside cell line-independent perturbation-response consensus signatures.

Abstract A030: Beyond the LNP: Self-amplifying RNA with LION nanoformulation technology for development of safe and effective cancer therapeutics

Abstract HDT Bio, a Seattle biotech company, has developed a platform technology based on self-amplifying RNA and a proprietary nanoparticle delivery system. mRNA have been increasingly used in the development of vaccines in both infectious diseases and oncology. Especially LNP- delivered mRNA has been deployed, following the success during the COVID pandemic, However, self-ampliying RNA (repRNA) possesses several features of particular relevance to cancer medicine. HDT has developed a nanoparticle technology named LION[TM] to safely and effectively deliver RNA to patients. In vivo studies showed that repRNA not only is capable of delivering robust cell-mediated immune responses but also doing so with a significanlty improved safety profile compared to administration using LNP-based formulations. These data will be presented in the context of clinical safety data with repRNA/LION. Furthermore, repRNA/LION was siuccessfully used to induce robust T-cell responses against tumor antigens, and will be discussed. Citation Format: Peter Berglund. Beyond the LNP: Self-amplifying RNA with LION nanoformulation technology for development of safe and effective cancer therapeutics [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 A030.

Abstract PR012: A first-in-class EGFR-directed KRAS G12V selective inhibitor

Abstract The KRAS proto-oncogene encodes a small GTPase that is crucial for the activation of intracellular signaling pathways that control cell proliferation, survival and differentiation. KRAS is frequently mutated in cancer resulting in its constitutive activation and dysregulation of downstream signaling pathways that drive oncogenic transformation. KRAS G12V is the second most common KRAS mutation in cancer, and occurs frequently in lung, colon and pancreatic cancers. However, while significant advancements have been made in developing KRAS G12C, G12D and pan-KRAS inhibitors, there remain no direct KRAS G12V inhibitors in the clinic. Due to challenges targeting oncogenes with traditional small molecule approaches, RNA interference (RNAi) has become an attractive therapeutic approach for many oncogenes. RNAi has faced many obstacles as an effective cancer therapeutics, including the lack of cancer- specific tissue targeting, rapid oligonucleotide nuclease degradation and clearance from circulation, the need for endosomal escape, and unwanted immune stimulation. However, recently, the use of targetable ligands conjugated to chemically modified siRNAs have shown promise in circumventing these barriers. Here, we describe the development of EFTX-G12V, a fully-modified, mutant-selective siRNA conjugated to an EGFR ligand that shows improved tumor delivery and significant anti-tumor activity in lung and colon cancer models. We used a structure-activity relationship screening approach to identify a highly mutant-selective fully chemically modified siRNA that inhibits KRAS G12V expression at both the mRNA and protein level while completely sparing KRAS WT. Furthermore, this siRNA inhibited cancer cell growth in vitro and showed no off-target effects. To address the issue of tumor-specific delivery, we conjugated a non-mitogenic EGFR ligand to the siRNA and found enhanced delivery to tumors with varying levels of EGFR expression. EFTX-G12V significantly inhibited KRAS G12V mRNA and protein in vivo and showed significant anti-tumor activity in lung and colon xenograft models. Importantly, EFTX-G12V showed no off-target effects on WT KRAS in somatic tissues including kidney, skin and bladder. Unexpectedly, we found that mutant-selective targeting showed improved efficacy in comparison to a pan-KRAS siRNA. EFTX-G12V significantly inhibited tumor angiogenesis while pan-KRAS targeting had inconsistent effects suggesting that mutant-selective targeting has advantages within the tumor microenvironment. Together our findings represent a technologic advance in ligand-directed, mutant-selective oncogene targeting using RNAi and reveal new biologic insights in KRAS targeting that may have broader implications with regards to safety and efficacy. Citation Format: Lyla Stanland, Hayden Huggins, Alessandro Porrello, Yogitha Chareddy, Salma Azam, Jillian Perry, Pradeep Pallan, Kristina Whately, Lincy Edatt, Matthew Fleming, Jonah Im, Christina Gutierrez-Ford, Imani Simmons, Vandanaa Jayaprakash, Rani Sellers, Gabriela de la Cruz, Albert Wielgus, Martin Egli, Albert Bowers, Chad Pecot. A first-in-class EGFR-directed KRAS G12V selective inhibitor [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 PR012.

Have plastic culture models prevented the discovery of effective cancer therapeutics?

Conventional cell culture techniques generally fail to recapitulate the expression profiles or functional phenotypes of the in vivo equivalents they are meant to model. These cell culture models are indispensable for preclinical drug discovery and mechanistic studies. However, if our goal is to develop effective therapies that work as intended in the human body, we must revise our cell culture models to recapitulate normal and disease physiology to ensure that we identify compounds that are useful and effective beyond our in vitro models.

Incidence, definitions and outcomes of anthracycline induced subclinical and clinical left ventricular dysfunction: a systematic review and meta-analysis

Abstract Purpose To assess incidence and risk factors for anthracycline-induced left ventricular dysfunction, and associated mortality in order to inform patients and providers of the risk, as well as for clinical trial endeavours. Background Anthracyclines (ACs) are very effective cancer therapeutics, but their use is confronted by the risk of cardiotoxicity. Estimates of AC-induced cardiotoxicity based on systematic analyses are limited and have not recently been defined. We present here a systematic review and meta-analysis of the incidence of anthracycline induced subclinical (AC-LVD) and clinical LV dysfunction (AC-CHF) and AC-CHF related mortality in non-liposomal AC recipients over the last 3 decades. Methods We searched Ovid MEDLINE(R), Embase, Cochrane Database and other major databases from their inception until June 22, 2023 for studies examining the rate of AC induced cardiomyopathy in patients receiving ACs and anthraquinones for haematologic, breast (BC) and sarcomatous malignancies. Covidence was used to aid with the management of our systematic review. Screening of abstracts and data extraction was independently performed by 2 reviewers. Results 6,365 abstracts were reviewed, of which 74 were included in the final analysis. 72 studies (n=41,138) reported data on AC-LVD, and 47 studies (n=27,012) reported data on AC-CHF. The average age was 53 years and 50% of the patients were female. Data on cardiac function at baseline was available in only 70% of the studies. Overall, AC-LVD occurred in 8.2% (95% CI 6.8%-10.2% I2 97%) (Fig 1). AC-CHF was noted in 2.2% (95% CI 1.6% to 2.9%, I2 91%) (Fig 2A), mortality related to decompensated AC-CHF was 0.5% (95% CI 0.3%-0.9%, I2 88%) (Fig 2B) while total mortality rate among AC recipients was 24.9% (95% CI 14.8-38.7%, I2 99%). Incidence of AC-LVD was higher in doxorubicin recipients (vs other ACs 10.5% vs 5-5.6%), studies from North America & Asia (vs other regions; 9.3-9.6% vs 6.7%), and prospective studies (vs retrospective studies; 8.7% vs 7.5%). AC-LVD was more common in BC patients (vs other cancers; 8.7% vs 3.5-7.2%) while AC-CHF was more common in lymphoma patients (8.5% vs 1.6-4.1%). AC-LVD was 4.6 times (95% CI 1.2-17.1, p=0.02) more likely in patients with a mean age >70 (vs <70). 21 definitions for AC-LVD were used across the studies. The most common definition (15 studies; n=7904) was "any decline in LVEF from baseline" resulting in a 5.8% rate of AC-LVD. Conclusions AC-LVD and AC-CHF has been reported in up to 10% and 3% of AC recipients, respectively. AC-CHF related mortality occurs in <1% of anthracycline recipients and has a 2-3% share in overall mortality among these patients. The type of malignancy and anthracycline can influence the rate of AC-LVD, AC-CHF and AC-CHF related mortality. Global region, age of the patient population and study design also seem to influence incidence rates. There is noteworthy heterogeneity in definitions for cardiotoxicity across studies.

Engineered microparticles modulate arginine metabolism to repolarize tumor-associated macrophages for refractory colorectal cancer treatment

BackgroundArginase is abundantly expressed in colorectal cancer and disrupts arginine metabolism, promoting the formation of an immunosuppressive tumor microenvironment. This significant factor contributes to the insensitivity of colorectal cancer to immunotherapy. Tumor-associated macrophages (TAMs) are major immune cells in this environment, and aberrant arginine metabolism in tumor tissues induces TAM polarization toward M2-like macrophages. The natural compound piceatannol 3ʹ-O-glucoside inhibits arginase activity and activates nitric oxide synthase, thereby reducing M2-like macrophages while promoting M1-like macrophage polarization.MethodsThe natural compounds piceatannol 3ʹ-O-glucoside and indocyanine green were encapsulated within microparticles derived from tumor cells, termed PG/ICG@MPs. The enhanced cancer therapeutic effect of PG/ICG@MP was assessed both in vitro and in vivo.ResultsPG/ICG@MP precisely targets the tumor site, with piceatannol 3ʹ-O-glucoside concurrently inhibiting arginase activity and activating nitric oxide synthase. This process promotes increased endogenous nitric oxide production through arginine metabolism. The combined actions of nitric oxide and piceatannol 3ʹ-O-glucoside facilitate the repolarization of tumor-associated macrophages toward the M1 phenotype. Furthermore, the increase in endogenous nitric oxide levels, in conjunction with the photodynamic effect induced by indocyanine green, increases the quantity of reactive oxygen species. This dual effect not only enhances tumor immunity but also exerts remarkable inhibitory effects on tumors.ConclusionOur research results demonstrate the excellent tumor-targeting effect of PG/ICG@MPs. By modulating arginine metabolism to improve the tumor immune microenvironment, we provide an effective approach with clinical translational significance for combined cancer therapy.

Anti-cancer activity of brucine loaded Cu(OH)2/ZnO nanoparticles against chronic myeloid leukemia cell line (K562) via apoptotic signaling pathway

Background and objectiveChronic myeloid leukemia (CML) is marked by abnormal blood cell production and traditional treatments often cause severe side effects and resistance. This study improves cancer therapy by using copper (II) hydroxide (Cu(OH)₂) and zinc oxide (ZnO) nanoparticles combined with brucine (Bru) to enhance targeted drug delivery and efficacy. Materials and methodsBru-Cu(OH)₂-ZnO NPs were synthesized and characterized using various analytical techniques. Their cytotoxicity was evaluated on K562 myeloid leukemia cells through cell viability assays, dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining, and measurement of oxidative stress indicators such as nitric oxide and lipid peroxidation levels. Antioxidant activity was assessed by glutathione (GSH) levels, while apoptosis was investigated via Caspase 3 and 9 activity and gene expression analysis (Bax, p53, and Bcl-2) using real-time polymerase chain reaction (RT-PCR). ResultsThe novel Bru-Cu(OH)₂-ZnO NPs demonstrated significant anti-cancer activity by markedly reducing K562 cell viability and enhancing cytotoxicity in a dose-dependent manner. These nanoparticles effectively scavenged free radicals, increased lipid peroxidation and nitric oxide levels, and improved caspase activity. Notably, gene expression analysis revealed that Bru-Cu(OH)₂-ZnO NPs led to overexpression of pro-apoptotic genes (Bax and p53) and downregulation of the anti-apoptotic gene (Bcl-2), highlighting their potential as effective cancer therapeutics. ConclusionThe synthesized Bru-Cu(OH)2-ZnO NPs shown excellent anti-cancer efficacy against the K562 cell line. This study underscores the potential of combining bioactive compounds with metal oxide nanoparticles to enhance targeted drug delivery and therapeutic effectiveness, offering a promising approach for advancing cancer treatment.

Dietary plants for oral cancer prevention and therapy: A review of preclinical and clinical studies.

Oral cancer is a disease with high mortality and rising incidence worldwide. Although fragmentary literature on the anti-oral cancer effects of plant products has been published, a comprehensive analysis is lacking. In this work, a critical and comprehensive evaluation of oral cancer preventative or therapeutic effects of dietary plants was conducted. An exhaustive analysis of available data supports that numerous dietary plants exert anticancer effects, including suppression of cell proliferation, viability, autophagy, angiogenesis, invasion, and metastasis while promoting cell cycle arrest and apoptosis. Plant extracts and products target several cellular mechanisms, such as the reversal of epithelial-to-mesenchymal transition and the promotion of oxidative stress and mitochondrial membrane dysfunction by modulation of various signaling pathways. These agents were also found to regulate cellular growth signaling pathways by action on extracellular signal-regulated kinase and mitogen-activated protein kinase, inflammation via modulation of cyclooxygenase (COX)-1, COX-2, and nuclear factor-κB p65, and metastasis through influence of cadherins and matrix metalloproteinases. In vivo studies support these findings and demonstrate a decrease in tumor burden, incidence, and hyperplastic and dysplastic changes. Clinical studies also showed decreased oral cancer risk. However, high-quality studies should be conducted to establish the clinical efficacy of these plants. Overall, our study supports the use of dietary plants, especially garlic, green tea, longan, peppermint, purple carrot, saffron, tomato, and turmeric, for oral cancer prevention and intervention. However, further research is required before clinical application of this strategy.

Cellular and molecular mechanisms underlying the potential of betulinic acid in cancer prevention and treatment

BackgroundBetulinic acid (BA), which is a pentacyclic triterpenoid found in the bark of plane, birch, and eucalyptus trees, has emerged as a compound of significant interest in scientific research due to its potential therapeutic applications. BA has a range of well-documented pharmacological and biological effects, including antibacterial, immunomodulatory, diuretic, antiviral, antiparasitic, antidiabetic, and anticancer activities. Although numerous research studies have explored the potential anticancer effects of BA, there is a noticeable gap in the literature, highlighting the need for a more up-to-date and comprehensive evaluation of BA's anticancer potential. PurposeThe aim of this work is to critically assess the reported cellular and molecular mechanisms underlying the cancer preventive and therapeutic effects of BA. MethodsRelevant research on the inhibitory effects of BA against cancerous cells was searched using Science Direct, Scopus, Web of Science, and PubMed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. ResultsThe anticancer properties of BA are mediated by the activation of cell death and cell cycle arrest, production of reactive oxygen species, increased mitochondrial permeability, modulation of nuclear factor-κB and Bcl-2 family signaling. Emerging evidence also underscores the combined anticancer effects of BA with other natural bioactive compounds or approved drugs. Notably, several novel BA nanoformulations have been found to exhibit encouraging antineoplastic activities. ConclusionBA, whether used alone or in combination, or as a form of nanoformulation, shows significant potential for cancer prevention and treatment. Nevertheless, further detailed studies are necessary to confirm the therapeutic effectiveness of this natural compound.

Modulation of the Prostate Cancer Resistance Factor Hsp27 by the Chemotherapeutic Drugs Abiraterone, Cabazitaxel, Docetaxel and Enzalutamide.

The cytoprotective heat shock protein 27 (HSP27) acts as a protein chaperone, antioxidant, and apoptosis regulator and is involved in cytoskeletal remodeling in prostate cancer. This study was designed to assess the effect of prostate cancer therapeutics on HSP27 to identify drugs that may benefit from an HSP27 inhibitor combination therapy. Cell counting was utilized to assess drug treatment efficiency. Changes in protein levels after drug treatment were assessed using western blot analysis. Abiraterone, cabazitaxel, docetaxel and enzalutamide significantly reduced cell proliferation in LNCaP and PC3 cells. Treatment with abiraterone and enzalutamide led to a significant reduction in HSP27 protein levels. In contrast, treatment with cabazitaxel and docetaxel did not change the HSP27 protein levels. Treatment with abiraterone and enzalutamide reduces HSP27 protein in an AR-independent manner and thus suppresses HSP27-correlated resistance mechanisms. However, docetaxel and cabazitaxel do not alter HSP27 protein levels, so that taxanes' efficacy may be enhanced by combining them with HSP27-inhibiting drugs.

Extracting Systemic Anticancer Therapy and Response Information From Clinical Notes Following the RECIST Definition.

The RECIST guidelines provide a standardized approach for evaluating the response of cancer to treatment, allowing for consistent comparison of treatment efficacy across different therapies and patients. However, collecting such information from electronic health records manually can be extremely labor-intensive and time-consuming because of the complexity and volume of clinical notes. The aim of this study is to apply natural language processing (NLP) techniques to automate this process, minimizing manual data collection efforts, and improving the consistency and reliability of the results. We proposed a complex, hybrid NLP system that automates the process of extracting, linking, and summarizing anticancer therapy and associated RECIST-like responses from narrative clinical text. The system consists of multiple machine learning-/deep learning-based and rule-based modules for diverse NLP tasks such as named entity recognition, assertion classification, relation extraction, and text normalization, to address different challenges associated with anticancer therapy and response information extraction. We then evaluated the system performances on two independent test sets from different institutions to demonstrate its effectiveness and generalizability. The system used domain-specific language models, BioBERT and BioClinicalBERT, for high-performance therapy mentions identification and RECIST responses extraction and categorization. The best-performing model achieved a 0.66 score in linking therapy and RECIST response mentions, with end-to-end performance peaking at 0.74 after relation normalization, indicating substantial efficacy with room for improvement. We developed, implemented, and tested an information extraction system from clinical notes for cancer treatment and efficacy assessment information. We expect this system will support future cancer research, particularly oncologic studies that focus on efficiently assessing the effectiveness and reliability of cancer therapeutics.

Lineage-Selective Dependencies in Pediatric Cancers.

The quest for effective cancer therapeutics has traditionally centered on targeting mutated or overexpressed oncogenic proteins. However, challenges arise in cancers with low mutational burden or when the mutated oncogene is not conventionally targetable, which are common situations in childhood cancers. This obstacle has sparked large-scale unbiased screens to identify collateral genetic dependencies crucial for cancer cell growth. These screens have revealed promising targets for therapeutic intervention in the form of lineage-selective dependency genes, which may have an expanded therapeutic window compared to pan-lethal dependencies. Many lineage-selective dependencies regulate gene expression and are closely tied to the developmental origins of pediatric tumors. Placing lineage-selective dependencies in a transcriptional network model is helpful for understanding their roles in driving malignant cell behaviors. Here, we discuss the identification of lineage-selective dependencies and how two transcriptional models, core regulatory circuits and gene regulatory networks, can serve as frameworks for understanding their individual and collective actions, particularly in cancers affecting children and young adults.

NIR‐II Ratiometric Fluorescent Nanoplatform for Real‐Time Monitoring and Evaluating Cancer Sonodynamic Therapy Efficacy

AbstractReal‐time monitoring the therapeutic process of sonodynamic therapy (SDT) is essential to optimize the treatment course in time and eventually improve the efficacy. The generation of singlet oxygen (1O2) is a quintessential characteristic of SDT, which permits non‐invasive monitoring of SDT by real‐time imaging of 1O2 inside the tumor. Nonetheless, the majority of probes are unable to measure 1O2 in real time because of its short half‐life and strong oxidative capacity. Here, the study constructs a ratiometric nanoplatform (DTPI) utilizing two fluorescent probes and the sonosensitizer TiO2. The poisonous 1O2 generated by DTPI following ultrasonic (US) radiation efficiently destroys tumor cells. The structural disruption of fluorescent dye IR‐1061 by 1O2 leads to a reduction in the DTPI fluorescence signal at 1100 nm, while US radiation has no impact on the fluorescence signal at 1550 nm. Thus, DTPI provides a precise and consistent reflection of the treatment efficacy at the tumor site, leveraging the ratiometric fluorescence signal and variations in oxygen content throughout the treatment process. This ratiometric‐fluorescence‐based reflection strategy establishes an effective and dependable platform for the real‐time monitoring and assessment of the cancer therapeutic effect through ratiometric probes.

Development and crystal structures of a potent second-generation dual degrader of BCL-2 and BCL-xL

Overexpression of BCL-xL and BCL-2 play key roles in tumorigenesis and cancer drug resistance. Advances in PROTAC technology facilitated recent development of the first BCL-xL/BCL-2 dual degrader, 753b, a VHL-based degrader with improved potency and reduced toxicity compared to previous small molecule inhibitors. Here, we determine crystal structures of VHL/753b/BCL-xL and VHL/753b/BCL-2 ternary complexes. The two ternary complexes exhibit markedly different architectures that are accompanied by distinct networks of interactions at the VHL/753b-linker/target interfaces. The importance of these interfacial contacts is validated via functional analysis and informed subsequent rational and structure-guided design focused on the 753b linker and BCL-2/BCL-xL warhead. This results in the design of a degrader, WH244, with enhanced potency to degrade BCL-xL/BCL-2 in cells. Using biophysical assays followed by in cell activities, we are able to explain the enhanced target degradation of BCL-xL/BCL-2 in cells. Most PROTACs are empirically designed and lack structural studies, making it challenging to understand their modes of action and specificity. Our work presents a streamlined approach that combines rational design and structure-based insights backed with cell-based studies to develop effective PROTAC-based cancer therapeutics.

Abstract 2920: In vitro assays for investigating the effects of cancer therapeutics on bone

Abstract Bone microenvironment is an important factor in regulating bone metastasis. When cancer cells home to bone they secrete factors that stimulate osteoclast activity leading to increased bone resorption. Stimulatory factors released from the resorbed bone matrix in turn promote proliferation of cancer cells and this process, referred as the vicious cycle, often leads to osteolytic lesions in bone when osteoclastic bone resorption exceeds osteoblastic bone formation. The vicious cycle observed in osteolytic disease occurs also in osteoblastic metastases, and in addition cancer cells produce osteoblast-stimulating factors. Cancers with bone metastases often include both osteolytic and osteoblastic lesions. Our aim was to establish in vitro cell culture models to study the effects of cancer therapeutics on osteoblast and osteoclast differentiation and activity. In the osteoclast differentiation assay, human osteoclast precursor cells (Lonza) were cultured on bovine bone slices for 7 days. Denosumab was added in the cultures at day 0, and tartrate-resistant acid phosphatase isoform 5b (TRACP 5b) activity was measured from the culture medium collected at day 7. Osteoclast activity was studied by allowing osteoclasts resorb bone after 7 days’ maturation period for additional 3 days in the presence of odanacatib. The amount of C-terminal cross-linked telopeptides of type I collagen (CTX-I) was measured in the culture medium collected at day 10 to quantitate osteoclast activity. Denosumab and odanacatib showed strong concentration dependent inhibition of osteoclast differentiation and activity, respectively. A mouse osteoblast progenitor cell line KS483 (Pharmatest Services) was used to study differentiation and activity of osteoblasts with test compounds bone morphogenetic protein 2 (BMP-2) and estradiol (E2). In the osteoblast differentiation assay, the activity of cellular alkaline phosphatase (ALP), a marker of osteoblast differentiation, was measured at day 8. In the osteoblast activity assay, the cells were cultured for 13 days. N-terminal propeptide of type I procollagen (PINP) secreted into the culture medium was determined at day 11 to indicate the effects on organic bone formation and calcium deposition was determined at the end of the study as a marker of inorganic bone formation. BMP-2 and E2 stimulated osteoblast differentiation and activity indicated by the increase in ALP activity, PINP and calcium levels. We conclude that these culture systems can be used for studying the effects of cancer therapeutics and identifying new potential compounds affecting the disease process of bone metastases with different mechanisms of action. Citation Format: Jenni H. Mäki-Jouppila, Mervi Ristola, Jukka Rissanen, Katja Fagerlund. In vitro assays for investigating the effects of cancer therapeutics on bone [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 2920.

Abstract 1219: In vivo delivery of CRISPR-Cas9 using lipid nanoparticles enables ATAD3A gene depletion to enhance RAS-targeted therapy

Abstract Targeting mitochondrial oncoproteins presents a new concept in developing effective cancer therapeutics. ATAD3A is a nuclear-encoded mitochondrial enzyme that contributes to mitochondrial dynamics, cholesterol metabolism, and signal transduction. Our previous study has demonstrated elevated expression of ATAD3A in head and neck squamous cell carcinoma (HNSCC) primary tissues and cultured cell lines. Loss of function suppresses HNSCC cell growth and elicits tumor regression in orthotopic tumor-bearing mice. Mechanistically, ATAD3A interacts with ERK1/2 in the mitochondria of HNSCC cells in the presence of VDAC1, and the ATAD3A-ERK1/2 signaling axis drives HNSCC development in a RAS-independent fashion. CRISPR-Cas9 has revolutionized genome engineering and has been intensively used to modify cancer-associated genes. However, challenges remain as CRISPR editing components must be transported into cells to exert their function. There is a need to explore effective in vivo delivery systems to accelerate the clinical use of CRISPR-Cas9. As no drug is available to target ATAD3A directly, we developed CRISPR-based ATAD3A-targeting nanodrugs by loading Cas9 mRNA and anti-ATAD3A sgRNAs into lipid nanoparticles (LNPs) that have become clinically acceptable delivery system due to low toxicity and high delivery efficacy and biocompatibility. As expected, treatment tongue tumors established in NSG mice with LNP-sgATAD3A remarkably repressed tumor growth. Most interestingly, the addition of LNP-sgATAD3A to the RAS inhibitor salirasib potentiated anticancer activity for HNSCC compared with the efficacy resulting from single-arm treatment. These novel and significant findings demonstrate a novel approach to inhibiting ATAD3A in tumor cells and provide a possible therapeutic strategy to enhance the success of multimodality therapy in cancer patients. Citation Format: Fanghui Chen, Liwei Lang, Yamin Li, Wei Zheng, Yong Teng. In vivo delivery of CRISPR-Cas9 using lipid nanoparticles enables ATAD3A gene depletion to enhance RAS-targeted therapy [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 1219.

The Vitamin C Enantiomers Possess a Comparable Potency in the Induction of Oxidative Stress in Cancer Cells but Differ in Their Toxicity.

The use of vitamin C (VC) in high doses demonstrates a potent tumor suppressive effect by mediating a glucose-dependent oxidative stress in Kirsten rat sarcoma (KRAS) mutant cancer cells. VC with arsenic trioxide (ATO) is a promising drug combination that might lead to the development of effective cancer therapeutics. Considering that a tumor suppressive effect of VC requires its high-dose administration, it is of interest to examine the toxicity of two enantiomers of VC (enantiomer d-optical isomer D-VC and natural l-optical isomer L-VC) in vitro and in vivo. We show that the combinations of L-VC with ATO and D-VC with ATO induced a similar cytotoxic oxidative stress in KrasG12D-expressing mutant cancer cells as indicated by a substantial increase in reactive oxidative species (ROS) production and depolarization of mitochondria. To examine the L-VC and D-VC toxicity effects, we administered high doses of D-VC and L-VC to CD1 mice and carried out an evaluation of their toxic effects. The daily injections of L-VC at a dose of 9.2 g/kg for 18 days were lethal to mice, while 80% of mice remained alive following the similar high-dose administration of D-VC. Following the drug injection courses and histopathological studies, we determined that a natural form of VC (L-VC) is more harmful and toxic to mice when compared to the effects caused by the similar doses of D-VC. Thus, our study indicates that the two enantiomers of VC have a similar potency in the induction of oxidative stress in cancer cells, but D-VC has a distinctive lower toxicity in mice compared to L-VC. While the mechanism of a distinctive toxicity between D-VC and L-VC is yet to be defined, our finding marks D-VC as a more preferable option compared to its natural enantiomer L-VC in clinical settings.

Mitigating phospholipid peroxidation of macrophages in stress-induced tumor microenvironment by natural ALOX15/PEBP1 complex inhibitors

BackgroundThe intricate interactions between chronic psychological stress and susceptibility to breast cancer have been recognized, yet the underlying mechanisms remain unexplored. Danzhi Xiaoyao Powder (DZXY), a traditional Chinese medicine (TCM) formula, has found clinical utility in the treatment of breast cancer. Macrophages, as the predominant immune cell population within the tumor microenvironment (TME), play a pivotal role in orchestrating tumor immunosurveillance. Emerging evidence suggests that lipid oxidation accumulation in TME macrophages, plays a critical role in breast cancer development and progression. However, a comprehensive understanding of the pharmacological mechanisms and active components of DZXY related to its clinical application in the treatment of stress-aggravated breast cancer remains elusive. PurposeThis study sought to explore the plausible regulatory mechanisms and identify the key active components of DZXY contributing to its therapeutic efficacy in the context of breast cancer. MethodsInitially, we conducted an investigation into the relationship between the phagocytic capacity of macrophages damaged by psychological stress and phospholipid peroxidation using flow cytometry and LC–MS/MS-based phospholipomics. Subsequently, we evaluated the therapeutic efficacy of DZXY based on the results of the tumor size, tumor weight, the phospholipid peroxidation pathway and phagocytosis of macrophage. Additionally, the target-mediated characterization strategy based on binding of arachidonate 15-lipoxygenase (ALOX15) to phosphatidylethanolamine-binding protein-1 (PEBP1), including molecular docking analysis, microscale thermophoresis (MST) assay, co-immunoprecipitation analysis and activity verification, has been further implemented to reveal the key bio-active components in DZXY. Finally, we evaluated the therapeutic efficacy of isochlorogenic acid C (ICAC) based on the results of tumor size, tumor weight, the phospholipid peroxidation pathway, and macrophage phagocytosis in vivo. ResultsThe present study demonstrated that phospholipid peroxides, as determined by LC–MS/MS-based phospholipidomics, triggered in macrophages, which in turn compromised their capacity to eliminate tumor cells through phagocytosis. Furthermore, we elucidate the mechanism behind stress-induced PEBP1 to form a complex with ALOX15, thereby mediating membrane phospholipid peroxidation in macrophages. DZXY, demonstrates potent anti-breast cancer therapeutic effects by disrupting the ALOX15/PEBP1 interaction and inhibiting phospholipid peroxidation, ultimately enhancing macrophages' phagocytic capability towards tumor cells. Notably, ICAC emerged as a promising active component in DZXY, which can inhibit the ALOX15/PEBP1 interaction, thereby mitigating phospholipid peroxidation in macrophages. ConclusionCollectively, our findings elucidate stress increases the susceptibility of breast cancer by driving lipid peroxidation of macrophages and suggest the ALOX15/PEBP1 complex as a promising intervention target for DZXY.

Targeting SWI/SNF Complexes in Cancer: Pharmacological Approaches and Implications.

SWI/SNF enzymes are heterogeneous multi-subunit complexes that utilize the energy from ATP hydrolysis to remodel chromatin structure, facilitating transcription, DNA replication, and repair. In mammalian cells, distinct sub-complexes, including cBAF, ncBAF, and PBAF exhibit varying subunit compositions and have different genomic functions. Alterations in the SWI/SNF complex and sub-complex functions are a prominent feature in cancer, making them attractive targets for therapeutic intervention. Current strategies in cancer therapeutics involve the use of pharmacological agents designed to bind and disrupt the activity of SWI/SNF complexes or specific sub-complexes. Inhibitors targeting the catalytic subunits, SMARCA4/2, and small molecules binding SWI/SNF bromodomains are the primary approaches for suppressing SWI/SNF function. Proteolysis-targeting chimeras (PROTACs) were generated by the covalent linkage of the bromodomain or ATPase-binding ligand to an E3 ligase-binding moiety. This engineered connection promotes the degradation of specific SWI/SNF subunits, enhancing and extending the impact of this pharmacological intervention in some cases. Extensive preclinical studies have underscored the therapeutic potential of these drugs across diverse cancer types. Encouragingly, some of these agents have progressed from preclinical research to clinical trials, indicating a promising stride toward the development of effective cancer therapeutics targeting SWI/SNF complex and sub-complex functions.

Identification of Breast Cancer Immune-related Prognostic Characteristics in Tumor Microenvironment.

Accumulated evidence suggest that tumor microenvironment (TME) plays a crucial role in breast cancer (BRCA) progression and therapeutic effects. This study aimed to characterize immune-related BRCA subtypes in TME, and identify genes with prognostic value. RNA sequencing profiles with corresponding clinical data from The Cancer Genome Atlas (TCGA) database of BRCA patients were downloaded to evaluate immune infiltration using the single-sample gene set enrichment (ssGAEA) algorithm. Further, BRCA was clustered according to immune infiltration status by consensus clustering analysis. Using Venn analysis, differentially expressed genes (DEGs) were overlapped to obtain candidate genes. Kaplan-Meier (K-M) analysis was performed to identify prognostic genes, and the results were verified in the GEO and METABRIC datasets. RT-qPCR was conducted to detect the mRNA expression of prognostic genes. In the TCGA database, 3 immune-related BRCA subtypes were identified [cluster1 (C1), cluster2 (C2), and cluster3 (C2)]. The C2 subtype had better overall survival (OS) compared to the C1 subtype. Higher levels of immune markers and checkpoint protein were found in the C2 subtype than in others. By combining DEGs between BRCA and normal tissues, with the C1 and C2 subtypes associated with different OS, 25 BRCA candidate genes were identified. Among these, 8 genes were identified as prognostic genes for BRCA. RT-qPCR showed that the expressions of 2 genes were significantly elevated in BRCA tissues, while that of other genes were decreased. Three BRCA subtypes were identified with the immune index, which may help design advanced treatment of BRCA. The data code used for the analysis in this article was available on GitHub (https://github.com/tangzhn/BRCA1.git).