Improve Chemotherapy Efficacy Research Articles

Correlation of the abundance of MDSCs, Tregs, PD-1, and PD-L1 with the efficacy of chemotherapy and prognosis in gastric cancer.

The aim of this study was to investigate the relationship between tumor microenvironment markers (myeloid-derived suppressor cells [MDSCs], regulatory T cells [Tregs], programmed cell death 1 [PD-1], and programmed death ligand 1 [PD-L1]) and chemotherapy efficacy and prognosis in advanced gastric cancer, identifying potential monitoring indicators. Advanced gastric cancer patients' MDSC and Treg expression was measured by flow cytometry pre- and postchemotherapy; PD-1 and PD-L1 expression in cancer tissues was assessed by immunohistochemistry. Correlations with chemotherapy outcomes and prognosis were analyzed. Postchemotherapy reductions in MDSC and Treg levels correlated with chemotherapy efficacy (P <.01). Negative PD-1 and PD-L1 expression in cancer tissues predicted better chemotherapy responses (P <.01). Patients with lower MDSC and Treg levels and negative PD-1 and PD-L1 had significantly longer median progression-free survival (PFS) and overall survival (OS) (P <.05). In advanced gastric cancer, reduced peripheral blood MDSC and Treg levels postchemotherapy and negative PD-1 and PD-L1 expression in tissues are associated with improved chemotherapy efficacy and are independent prognostic factors for PFS and OS.

Dihydroartemisinin Sensitizes Lung Cancer Cells to Cisplatin Treatment by Upregulating ZIP14 Expression and Inducing Ferroptosis.

Despite significant advances in lung cancer treatment, cisplatin (DDP)-based chemotherapy remains a cornerstone for managing the disease. However, the prevalence of chemoresistance presents a major challenge, limiting its effectiveness and contributing to poor outcomes. This underscores the urgent need for novel therapeutic strategies to overcome chemoresistance and improve chemotherapy efficacy in lung cancer patients. Exploring approaches to sensitize tumors to cisplatin could enhance treatment responses and overall survival rates. Our study utilized a variety of lung cancer models, including cell lines, mouse models, and patient-derived organoids, to validate the synergistic cytotoxic effects of dihydroartemisinin (DHA) and cisplatin (DDP). When combined with DDP, we demonstrate that DHA is a promising therapeutic agent that effectively triggers ferroptosis in lung cancer cells, offering a potential strategy for overcoming chemoresistance. Mechanistically, the combination of DHA and DDP synergistically enhances ZIP14 expression, modulating iron homeostasis and upregulating oxidative stress, leading to both invitro and invivo ferroptosis. Notably, our findings revealed that the sequential administration of DDP followed by DHA significantly increases ZIP14 expression and induces superior therapeutic outcomes compared to the simultaneous administration or DHA followed by DDP. This observation underscores the importance of the drug administration order in optimizing treatment efficacy, providing new insights into enhancing chemotherapy response in lung cancer. Our findings suggest that combining dihydroartemisinin (DHA) with cisplatin (DDP) presents a promising strategy to overcome chemoresistance in lung cancer patients. Importantly, administering DHA during chemotherapy intervals could further optimize treatment outcomes, enhancing the overall efficacy of lung cancer chemotherapy.

Abstract PR-09: Temporally resolved proteomics identifies nidogen-2 as a co-target in pancreatic cancer that modulates fibrosis and therapy response

Abstract Pancreatic cancer (PC) is highly lethal, with a five-year survival rate of ∼13%. PC is characterised by progressive cancer-associated fibrosis. We and others have shown that targeting cancer fibrosis can improve chemotherapy efficacy and impair metastasis in pre-clinical models. As such, we aimed to use integrated temporal proteomics to dissect the matrix signatures of pancreatic tumours from the highly-metastatic KPC (Pdx1-Cre; LSL-K-rasG12D/+; LSL-p53R172H/+) and poorly-metastatic KPflC (Pdx1-Cre; LSL-K-rasG12D/+; LSL-p53fl/+) mouse models, with an aim to identify new metastatic drivers in this deadly disease. We collected pancreatic tissue from KPflC, KPC and wildtype (WT) controls at early (∼50 days), mid (∼90 days) and late-stage disease (∼200 days), enriched them for matrix proteins using ISDoT de-cellularisation and analysed them using data independent acquisition liquid chromatography-tandem mass spectrometry (DIA LC-MS/MS). DIA LC-MS/MS revealed an increased abundance of Nidogen-2 (NID2) in KPC tumours compared to KPflC. Organotypic matrices generated with NID2 CRISPR-interference (CRISPRi) CAFs had reduced fibrosis, shown via second harmonic generation (SHG) multiphoton imaging and Picrosirius Red/birefringence analysis. Organotypic invasion assays revealed that depletion of CAF NID2 significantly impeded the 3D invasion of cancer cells. Subcutaneous and orthotopic co-seeding experiments using NID2 CRISPRi CAFs with cancer cells showed that NID2 inhibition significantly impeded tumour growth and fibrosis. Intravital (in vivo) imaging with quantum dots revealed improved vascular patency in live NID2 targeted tumours, with improved response to chemotherapy. Strikingly, in orthotopic models, mice bearing NID2 targeting had significantly reduced liver metastasis and increased survival, revealing NID2 as a new stromal co-target in this aggressive disease. Citation Format: Paul Timpson, Brooke Pereira, Shona Ritchie, katie Gordon, Thomas Cox. Temporally resolved proteomics identifies nidogen-2 as a co-target in pancreatic cancer that modulates fibrosis and therapy response [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr PR-09.

Neutralizing IL-38 activates γδ T cell-dependent antitumor immunity and sensitizes for chemotherapy

BackgroundThe interleukin (IL)-1-family receptor antagonist IL-38 has emerged as a negative regulator of auto-inflammation. Given the intricate interplay between antitumor immunity and auto-inflammation, we hypothesized that blocking IL-38 may enhance...

Galunisertib promotes bevacizumab-induced vascular normalization in nasopharyngeal carcinoma: Multi-parameter MRI evaluation

Tumor vascular normalization (TVN) is associated with antitumor therapeutic efficacy in nasopharyngeal carcinoma (NPC). However, the short time window of TVN is the biggest hindrance to its wide clinical application. We investigated whether targeting TGFB can enhance the TVN effect of BEV-induced PDX models of NPC. We constructed mouse subcutaneous PDX models of NPC and classified the mice into four drug treatment groups, including placebo control, galunisertib, bevacizumab (BEV), and galunisertib + BEV. We performed MRI multi-parameter examinations at different time points and evaluated the vascular density, vascular structure, and tumor hypoxia microenvironment by histopathology. The efficacy of chemotherapy and drug delivery was evaluated by administering cisplatin (DDP). We found that combined therapy with galunisertib and BEV significantly delayed tumor growth, enhanced TVN effect, and improved chemotherapy efficacy compared with monotherapy. Mechanistically, galunisertib reversed the EMT process and inhibited the expression of HIF-1α and VEGF by downregulating LAMC2. Correlation analysis of MRI data and pathological indicators showed that there was a good correlation between them. In this study, we described a novel therapeutic strategy to enhance the TVN effect on NPC. Multi-parameter MRI imaging can replace pathological indicators for non-invasive and real-time monitoring of tumor anti-angiogenesis therapeutic response and guide clinical treatment decisions.

Aqueous Extracts of Ocimum gratissimum Sensitize Hepatocellular Carcinoma Cells to Cisplatin through BRCA1 Inhibition.

Ocimum gratissimum (O. gratissimum), a medicinal herb with antifungal and antiviral activities, has been found to prevent liver injury and liver fibrosis and induce apoptosis in hepatocellular carcinoma (HCC) cells. In this study, we evaluated the effect of aqueous extracts of O. gratissimum (OGE) on improving the efficacy of chemotherapeutic drugs in HCC cells. Proteomic identification and functional assays were used to uncover the critical molecules responsible for OGE-induced sensitization mechanisms. The antitumor activity of OGE in combination with a chemotherapeutic drug was evaluated in a mouse orthotopic tumor model, and serum biochemical tests were further utilized to validate liver function. OGE sensitized HCC cells to the chemotherapeutic drug cisplatin. Proteomic analysis and Western blotting validation revealed the sensitization effect of OGE, likely achieved through the inhibition of breast cancer type 1 susceptibility protein (BRCA1). Mechanically, OGE treatment resulted in BRCA1 protein instability and increased proteasomal degradation, thereby synergistically increasing cisplatin-induced DNA damage. Moreover, OGE effectively inhibited cell migration and invasion, modulated epithelial-to-mesenchymal transition (EMT), and impaired stemness properties in HCC cells. The combinatorial use of OGE enhanced the efficacy of cisplatin and potentially restored liver function in a mouse orthotopic tumor model. Our findings may provide an alternate approach to improving chemotherapy efficacy in HCC.

Ketomimetic Medium Promotes Metastatic Disposition and Chemoresistance in Breast Cancer Cells through Hypersialylation and Lipid Synthesis.

Although metastasis accounts for the vast majority of cancer-related fatalities, the triggers for the metastatic transformation of breast cancer (BC) cells remain unknown. Recent evidence suggests that a common feature of invasive and resistant cells could be their metabolic state. However, attempts to control metabolic state via nutrient intake, e.g., ketogenic or low carbohydrate diets, have shown inconsistent results with respect to improving chemotherapy efficacy and curbing metastasis. Aiming to decode the molecular mechanisms that alter cell phenotype upon nutrient alteration, we study how a ketomimetic (ketone body-rich, low glucose) medium affects Doxorubicin (DOX) susceptibility and invasive disposition of BC cells. We quantified glycocalyx sialylation and found an inverse correlation with DOX-induced cytotoxicity and DOX internalization. These measurements were coupled with single-cell metabolic imaging, bulk migration studies, and transcriptomic and metabolomic analyses to map the mechanisms involved in ketone body-driven BC cell metabolic maneuvering. Our findings revealed that a ketomimetic medium enhances chemoresistance and invasive disposition of BC cells via two main oncogenic pathways: hypersialylation and lipid accumulation. We propose that the crosstalk between these pathways leads to synthesis of the glycan precursor UDP-GlcNAc, which leads to advancement of a metastatic phenotype in BC cells under ketomimetic conditions.

Effects of Dietary Modifications and Physical Activity on Cancer Prevention and Treatment

To prevent and treat cancer, this review aims to assess the goals, mechanisms, and advantages of altered diets and physical exercise. A comprehensive examination of scholarly publications from various databases, including Springer, Scopus, Elsevier, Google Scholar, Wiley, Web of Science, PubMed, and Taylor &amp; Francis, was the method utilized to obtain the data. Additionally, data compilation also made use of PhD and MSctheses. Despite the limited data available, diet modifications and intervention may prove to be beneficial to cancer patients, including reduced toxicity, improved chemotherapy efficacy, and curbing long term complications. Diet and physical activity are critical components of human survival. Imbalanced and improper levels of these factors might disrupt normal homeostasis and impair resilience to external stresses. This can show in a variety of ways, such as susceptibility to infections, cardio-metabolic disease, or cancer. Diet modifications coupled with physical activity may influence cancer risk in a variety of ways because some foods and drinks could predispose the consumers to cancer. Keywords: Cancer, diet, physical exercise, sedentary lifestyle

Co-targeting JAK1/STAT6/GAS6/TAM signaling improves chemotherapy efficacy in Ewing sarcoma

Ewing sarcoma is a pediatric bone and soft tissue tumor treated with chemotherapy, radiation, and surgery. Despite intensive multimodality therapy, ~50% patients eventually relapse and die of the disease due to chemoresistance. Here, using phospho-profiling, we find Ewing sarcoma cells treated with chemotherapeutic agents activate TAM (TYRO3, AXL, MERTK) kinases to augment Akt and ERK signaling facilitating chemoresistance. Mechanistically, chemotherapy-induced JAK1-SQ phosphorylation releases JAK1 pseudokinase domain inhibition allowing for JAK1 activation. This alternative JAK1 activation mechanism leads to STAT6 nuclear translocation triggering transcription and secretion of the TAM kinase ligand GAS6 with autocrine/paracrine consequences. Importantly, pharmacological inhibition of either JAK1 by filgotinib or TAM kinases by UNC2025 sensitizes Ewing sarcoma to chemotherapy in vitro and in vivo. Excitingly, the TAM kinase inhibitor MRX-2843 currently in human clinical trials to treat AML and advanced solid tumors, enhances chemotherapy efficacy to further suppress Ewing sarcoma tumor growth in vivo. Our findings reveal an Ewing sarcoma chemoresistance mechanism with an immediate translational value.

Gelatin nanoparticles loaded with 3-alkylpyridinium salt APS7, an analog of marine toxin, are a promising support in human lung cancer therapy

This study demonstrates the potential of gelatin nanoparticles as a nanodelivery system for antagonists of nicotinic acetylcholine receptors (nAChRs) to improve chemotherapy efficacy and reduce off-target effects. Too often, chemotherapy for lung cancer does not lead to satisfactory results. Therefore, new approaches directed at multiple pharmacological targets in cancer therapy are being developed. Following the activation of nAChRs (e.g. by nicotine), cancer cells begin to proliferate and become more resistant to chemotherapy-induced apoptosis. This work shows that the 3-alkylpyridinium salt, APS7, a synthetic analog of a toxin from the marine sponge Haliclona (Rhizoneira) sarai, acts as an nAChR antagonist that inhibits the pro-proliferative and anti-apoptotic effects of nicotine on A549 human lung adenocarcinoma cells. In this study, gelatin-based nanoparticles filled with APS7 (APS7-GNPs) were prepared and their effects on A549 cells were compared with that of free APS7. Both APS7 and APS7-GNPs inhibited Ca2+ influx and increased the efficacy of cisplatin chemotherapy in nicotine-stimulated A549 cells. However, significant benefits from APS7-GNPs were observed – a stronger reduction in the proliferation of A549 lung cancer cells and a much higher selectivity in cytotoxicity towards cancer cells compared with non-tumorigenic lung epithelial BEAS-2B cells.

Overcoming chemoresistance in triple-negative breast cancer (TNBC): Targeting PD-L1 stability and ferroptosis through integrated lipid metabolism and immune modulation.

e15149 Background: Triple-negative breast cancer (TNBC) is notorious for its aggressive nature and high recurrence rates, exacerbated by the lack of specific molecular targets, leading to poor prognosis and emergent chemoresistance. Our study explores ferroptosis mechanisms in TNBC, focusing on the interaction between lipid metabolism and immune system modulation to identify targets that enhance chemosensitivity, potentially improving chemotherapy efficacy. Methods: We employed RNA transcriptomics, proteomics, metabolomics, and lipidomics to compare gene transcription, protein expression, and metabolic profiles between TNBC cell lines MDA-MB-231/ADR (doxorubicin-resistant) and MDA-MB-231/S (sensitive). The impact of the ferroptosis inducer Erastin on MDA-MB-231/ADR was assessed through lipidomics. We also performed gene expression profiling on 152 TNBC patients unresponsive to Anthracycline-based chemotherapy, correlating with data from TCGA and METABRIC. Functional loss and gain experiments were undertaken to explicate the role of the SCD1-TRIM28-PD-L1 axis in mediating ADR resistance. Immunohistochemistry and RT-qPCR analyses were performed on tumor tissues and serum EVs from TNBC patients to identify chemosensitivity-enhancing targets. Results: Our investigation revealed marked transcriptional and proteomic variances between MDA-MB-231/ADR and MDA-MB-231/S cell lines, with SCD1 showing significant upregulation at both mRNA and protein levels. Metabolomic analyses revealed distinct lipid metabolic profiles between these two cell lines. Further studies found that Erastin treatment increased PD-L1 expression, along with changes in SCD1, p53, and TNFAIP3 expression levels. These molecules are closely associated with poor prognosis and resistance to therapy. Our findings also elucidated that TRIM28 modulates PD-L1 stability via SUMOylation and facilitates p53 ubiquitination and degradation through a TRIM28-MDM2 dependent pathway, thereby impacting immune surveillance and therapeutic response. Additionally, in TNBC patients treated with anthracycline-based chemotherapy, higher SCD1 and TNFAIP3 but lower TRIM28 expressions were observed in the PD/SD group compared to PR/CR. Similar expression patterns were observed in serum EVs. Conclusions: Our study highlights the potential of targeting the SCD1-TRIM28-PD-L1 axis in TNBC to overcome chemoresistance. We propose combining SCD1 inhibition with ferroptosis inducers to enhance PD-L1 blockade efficacy, offering a promising approach for TNBC patients with limited response to Anthracycline-based chemotherapy. This investigation represents a pivotal step towards advancing targeted therapeutics in TNBC, potentially transforming the clinical management of this aggressive and refractory breast cancer subtype.

DOES EXERCISE CHANGE BLOOD FLOW TO TUMOURS? ACUTE AEROBIC EXERCISE EFFECTS ON LIVER METASTASES BLOOD FLOW: A CASE SERIES

AIM Effective cancer treatment relies on intravenous chemotherapy penetrating the entire tumour in sufficient concentrations, which is largely reliant on effective blood supply into and within the tumour. However, tumours contain abnormal vasculature with inefficient blood perfusion leading to the inability for chemotherapy to reach the target tumour. Pre-clinical evidence suggests acute exercise may increase blood flow by 200%. However, most pre-clinical studies investigate the effects of light-to-moderate intensity exercise and subsequently there is little evidence regarding the most effective exercise intensity for improved tumour vasculature. Therefore, the aim of this ongoing case series is to determine whether exercise changes tumour blood flow in a clinical model using non-invasive techniques, and how exercise intensity effects degree of change in blood flow to tumours in patients with liver metastases. METHODS Participants were eligible if they were aged over 18 years, had stage IV cancer with liver metastasis and ECOG 0-2. The study visit consisted of an aerobic fitness test (YMCA) to determine cardiorespiratory fitness and three 5-minute bouts of exercise at low, moderate and high intensities. After each exercise bout, Doppler ultrasound was used to measure a liver tumour vessel and the hepatic artery (as a control) to determine blood flow parameters. RESULTS Exercise increased peak systolic velocities (PSV) to liver tumours at all intensities compared to rest. Moderate and high exercise intensities showed a marked increase in PSV within the first 2 minutes after exercise. The hepatic artery showed less variability in PSV with time compared to the liver tumour. Cardiorespiratory fitness did not affect tumour PSV. CONCLUSION The results of this case series thus far suggest that exercise increases tumour blood flow at all exercise intensities with particular emphasis on moderate and high intensities. This supports the potential for using exercise as an adjunct to standard treatment to improve chemotherapy efficacy.

Minocycline and photodynamic priming significantly improve chemotherapy efficacy in heterotypic spheroids of pancreatic ductal adenocarcinoma

The prognosis for patients with advanced-stage pancreatic ductal adenocarcinoma (PDAC) remains dismal. It is generally accepted that combination cancer therapies offer the most promise, such as Folforinox, despite their associated high toxicity. This study addresses the issue of chemoresistance by introducing a complementary dual priming approach to attenuate the DNA repair mechanism and to improve the efficacy of a type 1 topoisomerase (Top1) inhibitor. The result is a regimen that integrates drug-repurposing and nanotechnology using 3 clinically relevant FDA-approved agents (1) Top1 inhibitor (irinotecan) at subcytotoxic doses (2) benzoporphyrin derivative (BPD) as a photoactive molecule for photodynamic priming (PDP) to improve the delivery of irinotecan within the cancer cell and (3) minocycline priming (MNP) to modulate DNA repair enzyme Tdp1 (tyrosyl-DNA phosphodiesterase) activity. We demonstrate in heterotypic 3D cancer models that incorporate cancer cells and pancreatic cancer-associated fibroblasts that simultaneous targeting of Tdp1 and Top1 were significantly more effective by employing MNP and photoactivatable multi-inhibitor liposomes encapsulating BPD and irinotecan compared to monotherapies or a cocktail of dual or triple-agents. These data are encouraging and warrant further work in appropriate animal models to evolve improved therapeutic regimens.

Ginsenoside Rh4 alleviates gastrointestinal mucositis and enhances chemotherapy efficacy through modulating gut microbiota

BackgroundGastrointestinal mucositis stands as one of the most severe side effects of irinotecan (CPT-11). however, only palliative treatment is available at present. Therefore, there is an urgent need for adjunctive medications to alleviate the side effects of CPT-11. PurposeIn this study, our objective was to explore whether ginsenoside Rh4 could serve as a modulator of the gut microbiota and an adjunctive agent for chemotherapy, thereby alleviating the side effects of CPT-11 and augmenting its anti-tumor efficacy. Study designA CPT-11-induced gastrointestinal mucositis model was used to investigate whether ginsenoside Rh4 alleviated CPT-11-induced gastrointestinal mucositis and enhanced the anti-tumor activity of CPT-11. MethodsIn this study, we utilized CT26 cells to establish a xenograft tumor model, employing transcriptomics, genomics, and metabolomics techniques to investigate the impact of ginsenoside Rh4 on CPT-11-induced gastrointestinal mucositis and the effect on the anti-tumor activity of CPT-11. Furthermore, we explored the pivotal role of gut microbiota and their metabolites through fecal microbiota transplantation (FMT) experiments and supplementation of the key differential metabolite, hyodeoxycholic acid (HDCA). ResultsThe results showed that ginsenoside Rh4 repaired the impairment of intestinal barrier function and restored intestinal mucosal homeostasis in a gut microbiota-dependent manner. Ginsenoside Rh4 treatment modulated gut microbiota diversity and upregulated the abundance of beneficial bacteria, especially Lactobacillus_reuteri and Akkermansia_muciniphila, which further regulated bile acid biosynthesis, significantly promoted the production of the beneficial secondary bile acid hyodeoxycholic acid (HDCA), thereby alleviating CPT-11-induced gut microbiota dysbiosis. Subsequently, ginsenoside Rh4 further alleviated gastrointestinal mucositis through the TGR5-TLR4-NF-κB signaling pathway. On the other hand, ginsenoside Rh4 combination therapy could further reduce the weight and volume of colon tumors, promote tumor cell apoptosis, and enhance the anti-tumor activity of CPT-11 by inhibiting the PI3K-Akt signaling pathway, thus exerting a synergistic anti-tumor effect. ConclusionIn summary, our findings confirm that ginsenoside Rh4 can alleviate CPT-11-induced gastrointestinal mucositis and enhance the anti-tumor activity of CPT-11 by modulating gut microbiota and its related metabolites. Our study validates the potential of ginsenoside Rh4 as a modulator of the gut microbiota and an adjunctive agent for chemotherapy, offering new therapeutic strategies for addressing chemotherapy side effects and improving chemotherapy efficacy.

Effect of the combined binding of topotecan and catechin/protocatechuic acid to a pH-sensitive DNA tetrahedron on release and cytotoxicity: Spectroscopic and calorimetric studies

The therapeutic efficacy of chemotherapy drugs can be effectively improved through the dual effects of their combination with natural polyphenols and the delivery of targeted DNA nanostructures. In this work, the interactions of topotecan (TPT), (+)-catechin (CAT), or protocatechuic acid (PCA) with a pH-sensitive DNA tetrahedron (MUC1-TD) in the binary and ternary systems at pHs 5.0 and 7.4 were investigated by fluorescence spectroscopy and calorimetry. The intercalative binding mode of TPT/CAT/PC to MUC1-TD was confirmed, and their affinity was ranked in the order of PCA > CAT > TPT. The effects of the pH-sensitivity of MUC1-TD and different molecular structures of CAT and PCA on the loading, release, and cytotoxicity of TPT were discussed. The weakened interaction under acidic conditions and the co-loading of CAT/PCA, especially PCA, improved the release of TPT loaded by MUC1-TD. The targeting of MUC1-TD and the synergistic effect with CAT/PCA, especially CAT, enhanced the cytotoxicity of TPT on A549 cells. For L02 cells, the protective effect of CAT/PCA reduced the damage caused by TPT. The single or combined TPT loaded by MUC1-TD was mainly concentrated in the nucleus of A549 cells. This work will provide key information for the combined application of TPT and CAT/PCA loaded by DNA nanostructures to improve chemotherapy efficacy and reduce side effects.

Evaluation of the Role of AXL in Fusion-positive Pediatric Rhabdomyosarcoma Identifies the Small-molecule Inhibitor Bemcentinib (BGB324) as Potent Chemosensitizer.

Rhabdomyosarcoma (RMS) is a highly aggressive pediatric cancer with features of skeletal muscle differentiation. More than 80% of the high-risk patients ultimately fail to respond to chemotherapy treatment, leading to limited therapeutic options and dismal prognostic rates. The lack of response and subsequent tumor recurrence is driven in part by stem cell-like cells, the tumor subpopulation that is enriched after treatment, and characterized by expression of the AXL receptor tyrosine kinase (AXL). AXL mediates survival, migration, and therapy resistance in several cancer types; however, its function in RMS remains unclear. In this study, we investigated the role of AXL in RMS tumorigenesis, migration, and chemotherapy response, and whether targeting of AXL with small-molecule inhibitors could potentiate the efficacy of chemotherapy. We show that AXL is expressed in a heterogeneous manner in patient-derived xenografts (PDX), primary cultures and cell line models of RMS, consistent with its stem cell-state selectivity. By generating a CRISPR/Cas9 AXL knock-out and overexpressing models, we show that AXL contributes to the migratory phenotype of RMS, but not to chemotherapy resistance. Instead, pharmacologic blockade with the AXL inhibitors bemcentinib (BGB324), cabozantinib and NPS-1034 rapidly killed RMS cells in an AXL-independent manner and augmented the efficacy of the chemotherapeutics vincristine and cyclophosphamide. In vivo administration of the combination of bemcentinib and vincristine exerted strong antitumoral activity in a rapidly progressing PDX mouse model, significantly reducing tumor burden compared with single-agent treatment. Collectively, our data identify bemcentinib as a promising drug to improve chemotherapy efficacy in patients with RMS.

Abstract A104: Losartan rewires ovarian cancer tumor-immune microenvironment and suppresses IGF-1 to amplify chemo-immunotherapy sensitivity

Abstract Background: Ovarian Cancer (OvCa) is the most lethal gynecologic malignancy worldwide. The use of immune checkpoint inhibitors (ICIs) has revolutionized the therapy of several malignancies. Unfortunately, ICIs have had limited efficacy in OvCa, with objective response rates in only 10 to 15% of patients. Prevailing preclinical and clinical data indicate that abnormalities in the tumor microenvironment (TME) contribute to immunosuppression and dictate the outcome of ICIs. OvCa harbors an abnormal TME, characterized by a desmoplastic extracellular matrix with high collagen levels. The accumulation of extracellular matrix components gives rise to increased compressive forces within the tumor, leading to blood vessel collapse and vessel perfusion reduction, causing impaired drug delivery and compromised trafficking of cytotoxic T-cells. The resulting TME is hypoxic and immunosuppressive. In our attempts to normalize the TME, we discovered that angiotensin II receptor 1 (AT1) is a key regulator of compressive solid stress. We showed in OvCa models that treatment with losartan – a widely prescribed anti-hypertensive drug – reduced matrix content and re-opened compressed vessels. As a result, blood perfusion increased, leading to enhanced drug delivery and improved chemotherapy efficacy. Furthermore, our retrospective analysis demonstrated that treatment with angiotensin blockers is associated with a 30-month overall survival benefit in OvCa patients. As a natural extension of this study, we are now asking the question: Can losartan reprogram the immunosuppressive TME of OvCa to enhance immunotherapy alone or with chemotherapy? Methods and Results: Here, using two syngeneic immunocompetent OvCa models and genetic and pharmacologic perturbations, we discovered that losartan – a widely prescribed anti-hypertensive drug – exhibits dual effects on both the TME and cancer cells to sensitize OvCa to chemo-immunotherapy. Specifically, losartan treatment i) reprograms the TME, leading to increased vascular perfusion, and thus enhances ICI drug delivery and immune effector cell intratumoral infiltration and function; and ii) rewires the OvCa cells by suppressing the IGF-1 signaling, resulting in enhanced chemosensitivity. As a result of the combined tumor and stromal effects, losartan treatment enhances the efficacy of chemo-immunotherapy in OvCa models. Conclusions: Two of the greatest problems in ovarian cancer are chemotherapy resistance and the failure of immunotherapeutics to successfully alter the course of patients with OvCa. Our study offers a novel combination treatment strategy that can potentially enhance chemo-immunotherapy efficacy. As one of the most prescribed drugs for hypertension, the safety and low cost (less than $1-2/day) of losartan warrants rapid translation of our research to patients with OvCa. Citation Format: Yao Sun, Zhenzhen Yin, Limeng Wu, Changli Yue, Sonu Subudhi, Pinji Lei, Alona Muzikansky, Bo R. Rueda, Lei Xu. Losartan rewires ovarian cancer tumor-immune microenvironment and suppresses IGF-1 to amplify chemo-immunotherapy sensitivity [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A104.

Abstract B083: Single-cell and spatial transcriptomic characterization of treatment resistance and immune dynamics in high-grade serous ovarian cancer

Abstract B083: Single-cell and spatial transcriptomic characterization of treatment resistance and immune dynamics in high-grade serous ovarian cancer

Bioinspired ginsenoside Rg3 PLGA nanoparticles coated with tumor-derived microvesicles to improve chemotherapy efficacy and alleviate toxicity.

Breast cancer, a pervasive malignancy affecting women, demands a diverse treatment approach including chemotherapy, radiotherapy, and surgical interventions. However, the effectiveness of doxorubicin (DOX), a cornerstone in breast cancer therapy, is limited when used as a monotherapy, and concerns about cardiotoxicity persist. Ginsenoside Rg3, a classic compound of traditional Chinese medicine found in Panax ginseng C. A. Mey., possesses diverse pharmacological properties, including cardiovascular protection, immune modulation, and anticancer effects. Ginsenoside Rg3 is considered a promising candidate for enhancing cancer treatment when combined with chemotherapy agents. Nevertheless, the intrinsic challenges of Rg3, such as its poor water solubility and low oral bioavailability, necessitate innovative solutions. Herein, we developed Rg3-PLGA@TMVs by encapsulating Rg3 within PLGA nanoparticles (Rg3-PLGA) and coating them with membranes derived from tumor cell-derived microvesicles (TMVs). Rg3-PLGA@TMVs displayed an array of favorable advantages, including controlled release, prolonged storage stability, high drug loading efficiency and a remarkable ability to activate dendritic cells in vitro. This activation is evident through the augmentation of CD86+CD80+ dendritic cells, along with a reduction in phagocytic activity and acid phosphatase levels. When combined with DOX, the synergistic effect of Rg3-PLGA@TMVs significantly inhibits 4T1 tumor growth and fosters the development of antitumor immunity in tumor-bearing mice. Most notably, this delivery system effectively mitigates the toxic side effects of DOX, particularly those affecting the heart. Overall, Rg3-PLGA@TMVs provide a novel strategy to enhance the efficacy of DOX while simultaneously mitigating its associated toxicities and demonstrate promising potential for the combined chemo-immunotherapy of breast cancer.

Identification of Hypoxia and Mitochondrial-related Gene Signature and Prediction of Prognostic Model in Lung Adenocarcinoma.

Background: The correlation between hypoxia and tumor development is widely acknowledged. Meanwhile, the foremost organelle affected by hypoxia is mitochondria. This study aims to determine whether they possess prognostic characteristics in lung adenocarcinoma (LUAD). For this purpose, a bioinformatics analysis was conducted to assess hypoxia and mitochondrial scores related genes, resulting in the successful establishment of a prognostic model. Methods: Using the single sample Gene Set Enrichment Analysis algorithm, the hypoxia and mitochondrial scores were computed. Differential expression analysis and weighted correlation network analysis were employed to identify genes associated with hypoxia and mitochondrial scores. Prognosis-related genes were obtained through univariate Cox regression, followed by the establishment of a prognostic model using least absolute shrinkage and selection operator Cox regression. Two independent validation datasets were utilized to verify the accuracy of the prognostic model using receiver operating characteristic and calibration curves. Additionally, a nomogram was employed to illustrate the clinical significance of this study. Results: 318 differentially expressed genes associated with hypoxia and mitochondrial scores were identified for the construction of a prognostic model. The prognostic model based on 16 genes, including PKM, S100A16, RRAS, TUBA4A, PKP3, KCTD12, LPGAT1, ITPRID2, MZT2A, LIFR, PTPRM, LATS2, PDIK1L, GORAB, PCDH7, and CPED1, demonstrates good predictive accuracy for LUAD prognosis. Furthermore, tumor microenvironments analysis and drug sensitivity analysis indicate an association between risk scores and certain immune cells, and a higher risk scores suggesting improved chemotherapy efficacy. Conclusion: The research established a prognostic model consisting of 16 genes, and a nomogram was developed to accurately predict the prognosis of LUAD patients. These findings may contribute to guiding clinical decision-making and treatment selection for patients with LUAD, ultimately leading to improved treatment outcomes.