Combination Cancer Therapy Research Articles

A Porphyrin-Based 3D Metal-Organic Framework Featuring [Cu8Cl6]10+ Cluster Secondary Building Units: Synthesis, Structure Elucidation, Anion Exchange, and Peroxidase-Like Activity.

Herein, we report a rare example of cationic three-dimensional (3D) metal-organic framework (MOF) of [Cu5Cl3(TMPP)]Cl5 ⋅ xSol (denoted as Cu-TMPP; H2TMPP=meso-tetrakis (6-methylpyridin-3-yl) porphyrin; xSol=encapsulated solvates) supported by [Cu8Cl6]10+ cluster secondary building units (SBUs) wherein the eight faces of the Cl--based octahedron are capped by eight Cu2+. Surface-area analysis indicated that Cu-TMPP features a mesoporous structure and its solvate-like Cl- counterions can be exchanged by BF4 -, PF6 -, and NO3 -. The polyvinylpyrrolidone (PVP) coated Cu-TMPP (denoted as Cu-TMPP-PVP) demonstrated good ROS generating ability, producing ⋅OH in the absence of light (peroxidase-like activity) and 1O2 on light irradiation (650 nm; 25 mW cm-2). This work highlights the potential of Cu-TMPP as a functional carrier of anionic guests such as drugs, for the combination therapy of cancer and other diseases.

Designing combination therapies for cancer treatment: application of a mathematical framework combining CAR T-cell immunotherapy and targeted radionuclide therapy.

Cancer combination treatments involving immunotherapies with targeted radiation therapy are at the forefront of treating cancers. However, dosing and scheduling of these therapies pose a challenge. Mathematical models provide a unique way of optimizing these therapies. Using a preclinical model of multiple myeloma as an example, we demonstrate the capability of a mathematical model to combine these therapies to achieve maximum response, defined as delay in tumor growth. Data from mice studies with targeted radionuclide therapy (TRT) and chimeric antigen receptor (CAR)-T cell monotherapies and combinations with different intervals between them was used to calibrate mathematical model parameters. The dependence of progression-free survival (PFS), overall survival (OS), and the time to minimum tumor burden on dosing and scheduling was evaluated. Different dosing and scheduling schemes were evaluated to maximize the PFS and optimize timings of TRT and CAR-T cell therapies. Therapy intervals that were too close or too far apart are shown to be detrimental to the therapeutic efficacy, as TRT too close to CAR-T cell therapy results in radiation related CAR-T cell killing while the therapies being too far apart result in tumor regrowth, negatively impacting tumor control and survival. We show that splitting a dose of TRT or CAR-T cells when administered in combination is advantageous only if the first therapy delivered can produce a significant benefit as a monotherapy. Mathematical models are crucial tools for optimizing the delivery of cancer combination therapy regimens with application along the lines of achieving cure, maximizing survival or minimizing toxicity.

Efficacy and safety of bispecific antibodies vs. immune checkpoint blockade combination therapy in cancer: a real-world comparison.

Emerging tumor immunotherapy methods encompass bispecific antibodies (BSABs), immune checkpoint inhibitors (ICIs), and adoptive cell immunotherapy. BSABs belong to the antibody family that can specifically recognize two different antigens or epitopes on the same antigen. These antibodies demonstrate superior clinical efficacy than monoclonal antibodies, indicating their role as a promising tumor immunotherapy option. Immune checkpoints are also important in tumor immunotherapy. Programmed cell death protein-1 (PD-1) is a widely acknowledged immune checkpoint target with effective anti-tumor activity. PD-1 inhibitors have demonstrated notable therapeutic efficacy in treating hematological and solid tumors; however, more than 50% of patients undergoing this treatment exhibit a poor response. However, ICI-based combination therapies (ICI combination therapies) have been demonstrated to synergistically increase anti-tumor effects and immune response rates. In this review, we compare the clinical efficacy and side effects of BSABs and ICI combination therapies in real-world tumor immunotherapy, aiming to provide evidence-based approaches for clinical research and personalized tumor diagnosis and treatment.

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.

Tumor-targeted PROTAC prodrug nanoplatform enables precise protein degradation and combination cancer therapy.

Proteolysis targeting chimeras (PROTACs) have emerged as revolutionary anticancer therapeutics that degrade disease-causing proteins. However, the anticancer performance of PROTACs is often impaired by their insufficient bioavailability, unsatisfactory tumor specificity and ability to induce acquired drug resistance. Herein, we propose a polymer-conjugated PROTAC prodrug platform for the tumor-targeted delivery of the most prevalent von Hippel-Lindau (VHL)- and cereblon (CRBN)-based PROTACs, as well as for the precise codelivery of a degrader and conventional small-molecule drugs. The self-assembling PROTAC prodrug nanoparticles (NPs) can specifically target and be activated inside tumor cells to release the free PROTAC for precise protein degradation. The PROTAC prodrug NPs caused more efficient regression of MDA-MB-231 breast tumors in a mouse model by degrading bromodomain-containing protein 4 (BRD4) or cyclin-dependent kinase 9 (CDK9) with decreased systemic toxicity. In addition, we demonstrated that the PROTAC prodrug NPs can serve as a versatile platform for the codelivery of a PROTAC and chemotherapeutics for enhanced anticancer efficiency and combination benefits. This study paves the way for utilizing tumor-targeted protein degradation for precise anticancer therapy and the effective combination treatment of complex diseases.

Cell Membrane-Coated Biomimetic Nanoparticles in Cancer Treatment.

Nanoparticle-based drug delivery systems hold promise for cancer treatment by enhancing the solubility and stability of anti-tumor drugs. Nonetheless, the challenges of inadequate targeting and limited biocompatibility persist. In recent years, cell membrane nano-biomimetic drug delivery systems have emerged as a focal point of research and development, due to their exceptional traits, including precise targeting, low toxicity, and good biocompatibility. This review outlines the categorization and advantages of cell membrane bionic nano-delivery systems, provides an introduction to preparation methods, and assesses their applications in cancer treatment, including chemotherapy, gene therapy, immunotherapy, photodynamic therapy, photothermal therapy, and combination therapy. Notably, the review delves into the challenges in the application of various cell membrane bionic nano-delivery systems and identifies opportunities for future advancement. Embracing cell membrane-coated biomimetic nanoparticles presents a novel and unparalleled avenue for personalized tumor therapy.

Orchestrating apoptosis and ferroptosis through enhanced sonodynamic therapy using amorphous UIO-66-CoOx

The development of efficient and multifunctional sonosensitizers is crucial for enhancing the efficacy of sonodynamic therapy (SDT). Herein, we have successfully constructed a CoOx-loaded amorphous metal-organic framework (MOF) UIO-66 (A-UIO-66-CoOx) sonosensitizer with excellent catalase (CAT)- and glutathione-oxidase (GSH-OXD)-like activities. The A-UIO-66-CoOx exhibits a 2.6-fold increase in singlet oxygen (1O2) generation under ultrasound (US) exposure compared to crystalline UIO-66 sonosensitizer, which is attributed to its superior charge transfer efficiency and consistent oxygen (O2) supply. Additionally, the A-UIO-66-CoOx composite reduces the expression of glutathione peroxidase (GPX4) by depleting glutathione (GSH) through Co3+ and Co2+ valence changes. The high levels of highly cytotoxic 1O2 and deactivation of GPX4 can lead to lethal lipid peroxidation, resulting in concurrent apoptosis and ferroptosis. Both in vitro and vivo tumor models comprehensively confirmed the enhanced SDT antitumor effect using A-UIO-66-CoOx sonosensitizer. Overall, this study emphasizes the possibility of utilizing amorphization engineering to improve the effectiveness of MOFs-based sonosensitizers for combined cancer therapies.

Codelivery of Doxorubicin and p53 Gene by β-Cyclodextrin-Based Supramolecular Nanoparticles Formed via Host-Guest Complexation and Electrostatic Interaction.

We developed a supramolecular system for codelivery of doxorubicin (Dox) and p53 gene based on a β-CD-containing star-shaped cationic polymer. First, a star-shaped cationic polymer consisting of a β-CD core and 3 arms of oligoethylenimine (OEI), named CD-OEI, was used to form a supramolecular inclusion complex with hydrophobic Dox. The CD-OEI/Dox complex was subsequently used to condense plasmid DNA via electrostatic interactions to form CD-OEI/Dox/DNA polyplex nanoparticles with positive surface charges that enhanced the cellular uptake of both Dox and DNA. This supramolecular drug and gene codelivery system showed high gene transfection efficiency and effective protein expression in cancer cells. The codelivery of Dox and DNA encoding the p53 gene resulted in reduced cell viability and enhanced antitumor effects at low Dox concentrations. With its enhanced cellular uptake and anticancer efficacy, the system holds promise as a delivery carrier for potential combination cancer therapies.

Engineered Luminescent Oncolytic Vaccinia Virus Activation of Photodynamic-Immune Combination Therapy for Colorectal Cancer.

Oncolytic virus therapy is currently regarded as a promising approach in cancer immunotherapy. It has greater therapeutic advantages for colorectal cancer that is prone to distant metastasis. However, the therapeutic efficacy and clinical application of viral agents alone for colorectal cancer remain suboptimal. In this study, an engineered oncolytic vaccinia virus (OVV-Luc) that expresses the firefly luciferase gene is developed and loaded Chlorin e6 (Ce6) onto the virus surface through covalent coupling, resulting in OVV-Luc@Ce6 (OV@C). The OV@C infiltrates tumor tissue and induces endogenous luminescence through substrate catalysis, resulting in the production of reactive oxygen species. This unique system eliminates the need for an external light source, making it suitable for photodynamic therapy (PDT) in deep tissues. Moreover, this synergistic effect between PDT and viral immunotherapy enhances dendritic cell maturation, macrophage polarization, and reversal of the immunosuppressive microenvironment. This synergistic effect has the potential to convert a "cold" into a "hot" tumor, it offers valuable insights for clinical translation and application.

Enzyme-activatable disk-shaped nanocarriers augment tumor permeability for breast cancer combination therapy

Enzyme-activatable disk-shaped nanocarriers augment tumor permeability for breast cancer combination therapy

Inhibition of Carbohydrate Metabolism Potentiated by the Therapeutic Effects of Oxidative Phosphorylation Inhibitors in Colon Cancer Cells.

Cancer cells undergo a significant level of "metabolic reprogramming" or "remodeling" to ensure an adequate supply of ATP and "building blocks" for cell survival and to facilitate accelerated proliferation. Cancer cells preferentially use glycolysis for ATP production (the Warburg effect); however, cancer cells, including colorectal cancer (CRC) cells, also depend on oxidative phosphorylation (OXPHOS) for ATP production, a finding that suggests that both glycolysis and OXPHOS play significant roles in facilitating cancer progression and proliferation. Our prior studies identified a semisynthetic isoflavonoid, DBI-1, that served as an AMPK activator targeting mitochondrial complex I. Furthermore, DBI-1 and a glucose transporter 1 (GLUT1) inhibitor, BAY-876, synergistically inhibited CRC cell growth in vitro and in vivo. We now report a study of the structure-activity relationships (SARs) in the isoflavonoid family in which we identified a new DBI-1 analog, namely, DBI-2, with promising properties. Here, we aimed to explore the antitumor mechanisms of DBIs and to develop new combination strategies by targeting both glycolysis and OXPHOS. We identified DBI-2 as a novel AMPK activator using an AMPK phosphorylation assay as a readout. DBI-2 inhibited mitochondrial complex I in the Seahorse assays. We performed proliferation and Western blotting assays and conducted studies of apoptosis, necrosis, and autophagy to corroborate the synergistic effects of DBI-2 and BAY-876 on CRC cells in vitro. We hypothesized that restricting the carbohydrate uptake with a KD would mimic the effects of GLUT1 inhibitors, and we found that a ketogenic diet significantly enhanced the therapeutic efficacy of DBI-2 in CRC xenograft mouse models, an outcome that suggested a potentially new approach for combination cancer therapy.

Strategi Intervensi Non-Farmakologi untuk Gangguan Tidur pada Pasien Kanker Payudara

This research aims to determine non-pharmacological intervention strategies in treating sleep disorders in breast cancer patients. The method uses a systematic review, by identifying nursing problems faced by breast cancer survivors, determining research questions, exploring relevant research, and carrying out data extraction. The results show that there are various non-pharmacological intervention strategies for sleep disorders in breast cancer patients, both single and combination therapy. These interventions such as Cognitive Behavioral Therapy for Insomnia (CBT-I), Sleep Hygiene Education (SHE), Bright Light Therapy (BLT), internet-based interventions, Acupressure, Acupuncture, Tai Chi, Dance Therapy, Mindfulness-Based Stress Reduction (MBSR) and Yoga. In conclusion, various non-pharmacological intervention strategies can be carried out by oncology nurses independently, where each intervention has its own advantages. In its implementation to patients, should adapt to cultural backgrounds, be flexible, easy to apply, doesn’t require large costs, effective, efficient, and focuses on patient needs. Keywords: Sleep Disorders, Non-pharmacological Intervention, Breast Cancer

Organic nanoparticles based on aza-boron dipyrromethene derivatives for combined photothermal and photodynamic cancer therapy

Cancer is one of the major diseases that threaten human being's health and life. Recently, phototherapy has gained great attention due to the advantages of high selectivity and low toxicity. Nonetheless, the development a single photosensitizer capable of simultaneously achieving photothermal and photodynamic effects remains a great challenge. Aza-boron-dipyrromethene (aza-BODIPY) dyes have been widely studied in biomedical area for their significant absorption in the near infrared region and high fluorescence quantum yield. In this contribution, three aza-BODIPY molecules (TAS-BP, TES-BP and TESO-BP) that conjugated with triphenylamine (TPA) or tetraphenylethylene (TPE) were designed and synthesized. The presence of donor-acceptor-donor pairs within compounds enables the intermolecular electron transfer, leading to the augmentation of near-infrared (NIR) absorbance and the generation of non-radiative heat. The nanoparticles were prepared via the assembly of the related organic compounds with amphiphilic polymer (DSPE-PEG2000), which were named as TAS-BP NPs, TES-BP NPs and TESO-BP NPs, respectively. Importantly, three nanoparticles can generate heat and reactive oxygen species (ROS) simultaneously induced by a single laser (808 nm). The photothermal conversion efficiency of TAS-BP NPs, TES-BP NPs and TESO-BP NPs were determined to be 64.5%, 65.7%, and 53.6%, respectively. Furthermore, the cellular experiments demonstrated the good biocompatibility and outstanding photocytotoxicity of three nanoparticles, and the TES-BP NPs exhibited the highest photodynamic/photothermal synergistic effect. Thus, the as-prepared organic nanomaterials were demonstrated as potential candidates for cancer treatment through phototherapy.

Abstract 3282: Endocrine resistance genes driving cross-resistance to current combination therapies in HR-positive breast cancer

Abstract Introduction: Treatment failure to multiple treatment lines in hormone receptor positive (HR+) patients brings cross-resistance into the stage. The study aimed to determine if tamoxifen resistance genes cause cross-resistance to commonly employed metastatic breast cancer (combination) treatments. Materials & Methods: Parental and tamoxifen resistant MCF7A models (BCAR3, BCAR4, EGFR, AKT1 and AKT2) were cultured for 10 days with different concentrations of tamoxifen and fulvestrant (endocrine therapy), ribo-, abema-, and palbociclib (CDK4/6 inhibitors) and alpelisib (PIK3CA inhibitor). Compounds were tested as mono- and combination therapy in replicate experiments estimating cell growth using the Sulforhodamine B assay and half maximal inhibitory concentration (IC50) was calculated by Graphpad PRISM v5 software. Resistance was declared when IC50 was significantly different from parental (p<0.05, Mann-Whitney U test). Results: The BCAR3, BCAR4 and EGFR models were not only resistant to tamoxifen but also to fulvestrant monotherapy (see table). In the two AKTs models the initial results could not be reproduced and were excluded from the study. The BCAR4 model was also resistant to all CDK4/6- and PIK3CA-inhibitors monotherapy. Analysis of the combination regimens demonstrated cross-resistance in the BCAR4 model for all compound combinations tested, in the EGFR model for all combinations except fulvestrant combined with alpelisib, and in the BCAR3 model only for tamoxifen combined with alpelisib. Discussion/Conclusion: Tamoxifen resistance genes BCAR3, BCAR4 and EGFR show various degrees of cross-resistance to other breast cancer treatments. It might be worthwhile to evaluate these genes or their associated biological pathways as predictive biomarkers for cross-resistance in HR+ breast cancer patients treated with the mentioned (combination) therapies. Summary of median IC50 (IQR) for different conditions parental BCAR3 BCAR4 EGFR AKT1 AKT2 Monotherapy Tamoxifen 9.8 (7.0) 47.3 (121) ** 2210 (1280) ** 515 (495) ** 8.0 (21.3) 3.8 (21.8) Fulvestrant 0.1 (0.35) 0.8 (0.8) ** 309 (407) ** 11.4 (37.7) ** Ribociclib 479 (285) 423 (1102) 3099 (1212)** 719 (669) Abemaciclib 94.9 (82.5) 28.9 (52.6) 206 (197) * 189 (172) Palbociclib 138 (163) 91.1 (107) 608 (347) ** 158 (128) Alpelisib 14.1 (676) 322 (94.0) 1424 (372) ** 375 (356) Combination therapy Tamoxifen with Ribociclib 1.7 (1.0) 17.2 (29.0) 111 (159) * 54.4 (35.8) * Abemaciclib 2.5 (1.9) 6.0 (10.7) 19.5 (15.0) ** 40.0 (53.6) * Palbociclib 1.6 (2.0) 5.4 (4.6) 74.9 (80.9) * 29.2 (3.1) * Alpelisib 2.1 (0.3) 9.6 (12.4)* 157 (69.9) * 17.8 (9.9) * Combination therapy Fulvestrant with Ribociclib 0.07 (0.02) 0.1 (0.3) 14.4 (8.8) * 6.9(16.8) * Abemaciclib 0.07 (0.02) 0.1 (0.1) 4.6 (2.6) ** 2.6 (6.5) * Palbociclib 0.2 (0.1) 0.2 (1.6) 5.6 (0.9) * 1.3 (1.5) * Alpelisib 0.05 (0.05) 1.6 (20.6) 13.3 (8.1) * 2.1 (0.9) *:p<0.05, **:p<0.01 compared to parental cell line. Citation Format: Zhangzan Huang, Noor Wortelboer, Corine Beaufort, Seda N. Ortak, Da-wei Chan, Hamit H. Dag, Jean Helmijr, John Martens, Maurice Jansen. Endocrine resistance genes driving cross-resistance to current combination therapies in HR-positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3282.

Abstract 2630: Identifying most promising combination therapies for immune suppressive breast cancer using a combined in vitro/in vivo approach

Abstract Combining epigenetic therapy with immunotherapy is a promising strategy to address the complexities of cancer biology. However, it's important to note that the field is still evolving, and more research is needed to understand the optimal combinations, timing, and patient populations that will benefit the most from these approaches. We evaluated a combination of two different checkpoint inhibitor therapies (anti-CTLA4 and anti-PD1) with two different hypomethylating agents (5-azacytidine, AZA and Decitabine, DEC) in vitro and in vivo using a mouse breast cancer cell line 4T1 known to be resistant towards checkpoint inhibition (CPi). Beside tumor cell killing and tumor volume measurement, cytokine expression and immune cell phenotyping was determined. In a co-culture assay with autologous T cells and 4T1 cells, antitumor efficacy weas increased in all combination arms using AZA but not in combination with DEC. The combination of AZA with anti-CTLA4 was significantly better than the respective monotherapies (oneway ANOVA, p< 0.001). This effect was observed as well in the combination with anti-PD1 and AZA, however it was less pronounced (oneway ANOVA, p< 0.01). Of note, AZA restored the CTLA4 expression on CD8+ T cells in vitro, which was reduced by co-culture with tumor cells alone. In the follow-up in vivo experiment we focus on the combination of both CPi with AZA on different treatment schedules in the combination arms. The combination of anti-CTLA4 and AZA in a staggered treatment schedule displayed significant efficacy compared to control (oneway ANOVA, p< 0.05). The implantation of 4T1 reduced the number of T cells in bone marrow (BM), peripheral blood (PB) and spleen of the mice, confirming the immune-suppressive nature of the breast cancer line. This effect was restored under treatment with AZA in monotherapy and combination with CPi. Interestingly AZA reduced the number of immunosuppressive MDSC in BM, spleen and in tumor tissue. Vice versa NK cells were increased in BM, spleen and tumor tissue under treatment with AZA. AZA reduced the number of circulation tumor cells in PB and increased as already shown in vitro the percentage of CD8/CTLA4++ in PB. The PCA analysis of 36 mouse cytokines in vivo displayed two main clusters separated mainly by the presence of absence of AZA in the treatment arms. The combination arms which displayed the highest efficacy showed an increase in CXCL1, G-CSF, IL-6, LIF, M-CSF, MCP-1 (CCL2) and MCP-3 (CCL7) and a decrease of IFN-gamma, CXCL2. This is in line with the more inflammatory pattern of the tumor infiltrating lymphocytes in those groups. In summary, we have strong evidence that AZA influences the immune landscape of breast cancer towards a more inflammatory subtype. The combination with CPi was superior to the monotherapy. In addition, our data indicate that the treatment schedule of the combination might have a crucial influence on efficacy. Citation Format: Hannah Silberzahn, Mattias Bleisch, Anne Löhr, Volker Knauff, Kanstantsin Lashuk, Julia B. Schueler. Identifying most promising combination therapies for immune suppressive breast cancer using a combined in vitro/in vivo approach [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 2630.

Abstract 4529: Characterization of PARP inhibitor combination therapies in triple-negative breast cancer

Abstract Introduction: Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer, with limited targeted treatment options. TNBC patients can, however, benefit from targeted drugs known as Poly (ADP-Ribose) Polymerase inhibitors (PARPi). PARPi disrupt DNA repair pathways by targeting tumors with germline BRCA1/2 mutations (BRCA-MUT) via synthetic lethality and PARP-DNA trapping mechanisms. Only 15-20% of the TNBC patient population are BRCA-MUT and can thus benefit from PARPi. However, preclinical studies and clinical trials have suggested that PARPi can also be effective in BRCA1/2 wild-type (BRCA-WT) cancer cells that have genomic phenotypes similar to BRCA-MUT cells, a phenomenon known as BRCAness. Previously, we used whole transcriptome analysis in a panel of TNBC cell lines to identify a 63-gene signature for BRCAness. The 63-gene signature was shown to predict response to PARPi with an accuracy of 86% in patient-derived xenografts, and was present in 45% of TNBC patients. We hypothesize that targeting genes in this 63-gene signature can enhance the sensitivity of PARPi in BRCA-WT and BRCA-MUT TNBC cells. Our aim is to identify and target genes from this signature that are involved in DNA synthesis and repair pathways, to identify effective combination strategies with PARPi. Methods: Using a PARPi-resistant TNBC cell line, MDAMB231, we carried out an siRNA screen of six genes from the 63-gene signature (BARD1, BUB1, RRM2, FEN1, EXO1, and USP1), chosen based on DNA repair functions and small-molecule inhibitor availability. The gene knockdowns were combined with the application of a potent PARPi, talazoparib, to determine the impact on DNA damage and cell death in TNBC cell lines. We then focused on targeting FEN1 function with the inhibitor LNT1. Using the Chou & Talalay combination index, we combined LNT1 with talazoparib to determine drug synergy in TNBC cell lines. Results: The individual siRNA knockdowns of BARD1, BUB1, FEN1, EXO1, and USP1, in combination with talazoparib, led to increased γ-H2AX and cleaved-caspase 3 levels, indicating augmentation of DNA damage and apoptosis. In particular, the FEN1 inhibitor, LNT1 demonstrated efficacy as a single-agent and synergy in combination with talazoparib in both BRCA-WT and BRCA-MUT TNBC cell lines. Conclusions: The siRNA screens, in combination with talazoparib, show that there are indeed targets within the 63-gene signature that can be used with PARPi that enhance DNA damage and cell death. The drug synergy shown between LNT1 and talazoparib in both BRCA-WT and BRCA-MUT TNBC cells suggests that LNT1 with PARPi could be an effective targeted combination approach, with great potential for TNBC patients. Citation Format: Elicia Fyle, Djihane Abdesselam, Mallory Frederick, Saima N. Hassan. Characterization of PARP inhibitor combination therapies in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4529.

Prediction of radiation complications by determining the blood oxidation processes in cervical cancer patients under chemoradiotherapy

Background. Radiotherapy (RT) is one of the principal methods in cancer management, and its administration in oncology practice is much wider nowadays because of the increased incidence of newly diagnosed cancer cases with wide spread and aggressive course of tumor process, and also in view of organ-sparing strategies in the combined treatment. However, the radiation reactions, especially local ones in rectum or bladder, can’t be completely avoided even using the most advanced radiotherapy facilities and dosimetry planning. Therefore, at present time not only technical modernization, but also the progress in radiobiology should be considered. Given the cytotoxic properties of some anticancer drugs, they are used in the combined therapy of cervical cancer (CC) to receive a radiosensitizing effect on the malignant cells. In particular, cisplatin inhibits reparative processes by affecting the enzymes involved in restoring the integrity of DNA or chromosome structure. Administration of the combined radiation and chemotherapy leads not only to an increase in the percentage of tumor regression, but also to an increase in the number of radiation injuries to healthy tissues. Therefore, prediction of such injuries, research and development of means of their prevention and treatment in the regimen of chemoradiotherapy (ChRT) of CC is extremely urgent and remains an unsolved problem to date. Purpose. Development of personalized approaches in ChRT in CC patients by studying its efficiency, assessing its toxicity, and predicting radiation injuries according to the data of blood oxidative processes in patients. Materials and methods. The combined radiotherapy (CRT) and ChRT were administered to the stage IIB–IIIB CC (T2b-3bN0-1M0) patients (n = 105) at the National Cancer Institute. Patients aged 25–75 years were divided into two groups: the study group and the comparison group. Complex clinical examination was conducted prior to treatment featuring the assay of tumor parameters, state of «critical organs». At the stage I of CRT regimen, conformal irradiation on pelvis minor was delivered at the electron linear accelerator «Clinac 2100 CD» with an energy of 6 MeV per area of pelvis minor with single radiation dose (SRD) of 2.0 Gy and total radiation dose (TRD) of up to 46 Gy. Patients in the study group received the CRT along with administration of chemoradiomodifying agent cisplatin 40 mg/m2 once a week intravenously (drip-feed), patients in the comparison group received no radiomodifier. At the stage II of CRT regimen, an intracavitary brachytherapy (ICBT) was administered to the CC patients at the gamma therapy equipment «AGAT-VU» using 60Co (high dose rate – HDR) sources in the mode of SRD of 5 Gy 2 times a week, 7–8 fractions, and TRD of 35–40 Gy at p. A. The TRD in total was 77–89 Gy at the p. A and 54–60 Gy at p. B. Administration of cisplatin 40 mg/m2 at the stage II of CRT was continued in the study group once a week intravenously (drip-feed), total dose of up to 200–300 mg. Radiobiological studies were performed on the peripheral blood samples from the CC patients (n = 39) before and after ChRT. The control group consisted of healthy women of the appropriate age. Blood was sampled into the special 6 ml Vacutainer type tubes with an anticoagulant according to the manufacturer’s instructions (BioReagent). Intensity of generation of О• 2– in PBL was evaluated by the chemiluminescence method using the lucigenin indicator, which, as a result of reacting with О• 2–, emits light quanta recorded by the device. Measurements were carried out on the AutoLumat LB 953 device (Germany) with appropriate corrections made to the methodology. Results and discussion. Effectiveness of CRT in CC patients was evaluated according to regression of the primary tumor focus (clinical, ultrasound, MRI or SCT data) and presence/absence of toxic manifestations of treatment following the criteria for evaluating the solid tumors regression according to the Response Evaluation Criteria in Solid Tumor (RECIST). Conclusions. The results of the study indicate that chemoradiotherapy contributes to pronounced regression of cervical tumors and does not increase toxicity of treatment due to timely correction of complications.

Abstract 7150: Molecular insights into the oncogenic influence between mutant HER3, mutant KRAS, and their synergistic interplay in colorectal cancer pathogenesis

Abstract Colorectal cancer (CRC) is a disease of the colon and rectum that will claim about 52,550 American lives in 2023. In recent years, more attention has been paid to HER2 and HER3’s roles in colorectal cancers, as they may cause resistance to targeted therapies. We are investigating the role of naturally co-occurring HER3 and KRAS mutations in colorectal cancer, as about 6% of all colorectal cancers contain a HER3 mutation and 41% contain a KRAS mutation. We have observed that there is a statistically significant co-occurrence of HER3 and KRAS mutations in CRCs while there is mutual exclusivity with mutations in EGFR or HER4 and mutant KRAS in CRC examining 6791 samples from 17 studies. There is a tendency for co-occurrence with HER2 and KRAS mutations that is not statistically significant in these CRC tumor samples. We have found that genetic knockdown of both KRAS and HER3 with siRNA targeting KRAS and HER3 in the CRC cell line SNU-407 (HER3V104M, KRASG12D) results in a statistical reduction in cell proliferation in comparison to genetic knockdown with only KRAS or HER3. Using the SW620 CRC cell line (HER3WT, KRASG12V) as a comparison, we have observed that knocking down HER3 using siRNA had no effect on cell proliferation whereas KRAS knockdown reduced proliferation and the combination showed no statistical difference compared to knocking down only KRAS. Additionally, we have found that there is a striking increase in total HER3 levels in SNU-407 cells when treated with the KRASG12D inhibitor MRTX1133. This feedback loop could limit the efficacy of the KRAS inhibitor. We wished to delineate mutant HER3’s binding partner(s) as HER3 is kinase impaired. Strikingly, we have found that EGFR immunoprecipitates with HER3 in SNU-407 cells. We are expanding our studies to CRC patient derived xenografts (PDXs) with co-occurring HER3 and KRAS mutations and have generated patient derived organoids from these PDXs. Ongoing studies are determining if there is a synergistic relationship with KRAS inhibitors and HER family inhibitors including a HER3 antibody-drug conjugate. Our findings may present a new paradigm for targeted combination therapies in colorectal cancer with the eventual goal of increased overall patient survival. Citation Format: Mary K. Kilroy, Briley Park, Rosalin Mishra, Wasim Feroz, Cecilia Wischmeier, Joan T. Garrett. Molecular insights into the oncogenic influence between mutant HER3, mutant KRAS, and their synergistic interplay in colorectal cancer pathogenesis [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 7150.

Dual biomarkers-activatable hollow MnO2-Based theranostic nanoplatform for efficient breast cancer-specific multisite fluorescence imaging and synergistic therapy

BackgroundTheranostic nanoplatforms with integrated diagnostic imaging and multiple therapeutic functions play a vital role in precise diagnosis and efficient treatment for breast cancer, but unfortunately, these nanoplatforms are usually stuck in single-site imaging and single mode of treatment, causing unsatisfactory diagnostic and therapeutic efficiency. Herein, a dual biomarkers-activatable facile hollow mesoporous MnO2 (H–MnO2)-based theranostic nanoplatform, DNAzyme@H–MnO2-MUC1 aptamer (DHMM), was constructed for the simultaneous multi-site diagnosis and multiple treatment of breast cancer. ResultsThe DHMM acted as an integrated diagnostic and therapeutic nanoplatform that realizes multi-site fluorescence imaging-guided high-efficient photothermal/chemodynamic/gene synergistic therapy (PTT/CDT/GT) for breast cancer. The H–MnO2 exhibits high loading capacity for Cy5-MUC1 aptamer (3.05 pmoL μg−1) and FAM-DNAzyme (3.37 pmoL μg−1), and excellent quenching for the probes. In the presence of MUC1 on the cell membrane and GSH in the cytoplasm, Cy5-MUC1 aptamer and FAM-DNAzyme was activated triggering dual-channel fluorescence imaging at different sites. Moreover, the self-supplied Mn2+ was further supplied as DNAzyme cofactors to catalytic cleavage intracellular EGR-1 mRNA for high-efficient GT and stimulated the Fenton-like reaction for CDT. The H–MnO2 also showcases a favorable photothermal performance with a photothermal conversion efficiency of 44.16%, which ultimately contributes to multi-site fluorescence imaging-guided synergistic treatment with an apoptosis rate of 71.82%. SignificanceThis dual biomarker-activatable multiple therapeutic nanoplatform was realized multi-site fluorescence imaging-guided PTT/CDT/GT combination therapy for breast cancer with higher specificity and efficiency, which provides a promising theranostic nanoplatform for the precision and efficiency of breast cancer treatment.

Abstract 4044: Potentiated antitumor activity of poly-γ-glutamic acid combined with anti PD-L1 blockade on murine models of colorectal cancer

Abstract Objective: Immune checkpoint inhibitors(ICIs) have been shown to be key role in cancer therapy. Especially, antibodies targeting programmed cell death ligand1(PD-L1) promoted T cells to activate immune response against cancer cells. However, the current ICIs still have insignificant to motivate effective antitumor immunity by blocking PD-1/PD-L1 pathway and the regulatory network of PD-L1 by cytokines in the tumor microenvironment remains to be uncovered. Previously, we have reported the anti-cancer effects of combination treatment with a natural product, poly-γ-glutamic acid(γ-PGA), and PD-1 blockade. Now, we show that combination therapy with anti PD-L1 and γ-PGA can overcome the limits of ICIs and enhance anticancer effect in murine colorectal cancer. Design: In vivo efficacy studies were performed by intraperitoneal injection of antibody targeting PD-L1 and oral administration of γ-PGA in C57BL/6 model transplanted with mouse tumor cell lines. Systemic changes in immunophenotype was measured by tumor volume size and body weight. The splenocyte was isolated from mice and the populations of myeloid-driven suppressor cells(MDSCs) and CD4/CD8 T cells were analyzed by FACS. Also, the significant cytokines activated by T- cell, IFN-γ and IL-2, were measured by ELISA. Results and Conclusions: In murine model of colorectal cancer, γ-PGA and anti PD-L1 blockade combination therapy significantly improved anti-tumor activity compared with single agents. In addition, tumoral infiltration of CD8+ T cells and IFN-γ productions were increased by γ-PGA, and its antitumoral activity was attenuated by antibody-mediated depletion of these cells, indicating that g-PGA suppressed tumor growth in a CD8 T cell-dependent manner. Therefore, our results suggest that γ-PGA promote ICI-mediated antitumor responses by the transformation of "cold tumors" into “hot tumors” Citation Format: Jae-Pyung Jang, Chan-Hee Yoo, Kyung-Soo Hahm, Do Young Lee, Young-Chul Park, Jae Chul Choi. Potentiated antitumor activity of poly-γ-glutamic acid combined with anti PD-L1 blockade on murine models of colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4044.