Effect Of Combination Therapy Research Articles

Radionuclide labeled nanocarrier for imaging guided combined radionuclide, sonodynamic, and photothermal therapy of pancreatic tumours

Radionuclide therapy (RNT) is an effective method for the clinical precise treatment of cancer. However, the uneven dose distribution and rapid metabolism of nuclides limit the effective killing of tumors. To overcome the limitations of radionuclide therapeutic approaches, combining different therapeutic strategies to treat cancer has manifested great promise in basic and clinical research. Here, a new combination therapy strategy was developed to combine radionuclide therapy, sonodynamic therapy and photothermal therapy (RNT-SDT-PTT) under radionuclide imaging guided achieve highly effective combination therapy. We prepared a polydopamine-modified Au nanostar (AN), then loaded with the acoustic sensitizer protoporphyrin (IX) and labeled with diagnostic (99mTc) or therapeutic (131I) radionuclides (131I/99mTc-AN@D/IX) for the precise diagnosis and treatment of pancreatic cancer. After intratumor administration, single photon emission computed tomography imaging showed that the nanocarriers were mostly retained in the tumor compared to free radionuclide. As well as using near-infrared light to trigger PTT and ultrasound with high penetration depth to activate IX to generate reactive oxygen species achieved SDT of tumor. The ultimate significantly improved the inhibitory effects by the RNT-SDT-PTT combined therapy for pancreatic cancer. Therefore, this study proposes an effective radionuclide combination therapy regimen consisting of three widely used treatments, offering promising prospects for the future of oncology.

A Multipronged Unbiased Strategy Guides the Development of an Anti-EGFR/EPHA2-Bispecific Antibody for Combination Cancer Therapy.

Accumulating analyses of pro-oncogenic molecular mechanisms triggered a rapid development of targeted cancer therapies. Although many of these treatments produce impressive initial responses, eventual resistance onset is practically unavoidable. One of the main approaches for preventing this refractory condition relies on the implementation of combination therapies. This includes dual-specificity reagents that affect both of their targets with a high level of selectivity. Unfortunately, selection of target combinations for these treatments is often confounded by limitations in our understanding of tumor biology. Here, we describe and validate a multipronged unbiased strategy for predicting optimal co-targets for bispecific therapeutics. Our strategy integrates ex vivo genome-wide loss-of-function screening, BioID interactome profiling, and gene expression analysis of patient data to identify the best fit co-targets. Final validation of selected target combinations is done in tumorsphere cultures and xenograft models. Integration of our experimental approaches unambiguously pointed toward EGFR and EPHA2 tyrosine kinase receptors as molecules of choice for co-targeting in multiple tumor types. Following this lead, we generated a human bispecific anti-EGFR/EPHA2 antibody that, as predicted, very effectively suppresses tumor growth compared with its prototype anti-EGFR therapeutic antibody, cetuximab. Our work not only presents a new bispecific antibody with a high potential for being developed into clinically relevant biologics, but more importantly, successfully validates a novel unbiased strategy for selecting biologically optimal target combinations. This is of a significant translational relevance, as such multifaceted unbiased approaches are likely to augment the development of effective combination therapies for cancer treatment. See related commentary by Kumar, p. 2570.

The heterogeneous transition state of resistance to RET kinase inhibitors converges on ERK1/2-driven Aurora A/B kinases

AimWhile most patients with RET-altered cancer responded to the RET protein tyrosine kinase inhibitors (TKIs) pralsetinib (BLU667) and selpercatinib (LOXO292), few achieved a complete response. Heterogeneity in residual tumors makes it difficult to target their diverse genetic alterations individually. The aim of this study is to characterize the cancer cells that persist under continuous RET TKI treatment and identify the shared vulnerability of these cells. MethodsWe analyzed residual RET-altered cancer cells under prolonged RET TKI treatment by whole exome sequencing (WES), RNA-seq analysis, and drug-sensitivity screening. These were followed by tumor xenograft experiments of mono- and combinational drug treatments. ResultsBLU667- and LOXO292-tolerated persisters were cellularly heterogeneous, contained slowly proliferating cells, regained low levels of active ERK1/2, and displayed plasticity in growth rate, which we designated as in the transition state of resistance (TSR). TSR cells were genetically heterogeneous. Aurora A/B kinases were among the most significantly upregulated genes and that the MAPK pathway activity had significantly higher transcript footprints. MEK1/2 and Aurora kinase inhibitors were the most effective drugs when combined with a RET kinase inhibitor. In a TSR tumor model, combination of BLU667 with an Aurora kinase or a MEK1/2 kinase inhibitor caused TSR tumor regression. ConclusionOur experiments reveal that the heterogeneous TSR cancer cells under continuous RET TKI treatment converge on the targetable ERK1/2-driven Aurora A/B kinases. The discovery of the targetable convergent point in the genetically heterogeneous TSR points to an effective combination therapy approach to eliminate the residual tumors.

The role of ubiquitin pathway-mediated regulation of immune checkpoints in cancer immunotherapy.

With the continuous cognition of the relationship between tumor cells and tumor immune microenvironment, immunotherapy based on the immune checkpoint blockade has achieved great breakthroughs, led to improved clinical outcomes, and prolonged survival for cancer patients in recent years. Nevertheless, the de novo or acquired resistance to immunotherapy has greatly counteracted the efficacy, leading to a 20%-40% overall response rate. Thus, further in-depth understanding of the regulation of the tumor microenvironment and antitumor immunity is urgently warranted. Ubiquitination-mediated protein degradation plays vital roles in protein stabilization, activation, and dynamics as well as in cellular homeostasis modulation. The dysregulated ubiquitination and deubiquitination are closely related to the changes in physiological and pathological processes, which subsequently result in a variety of diseases including cancer. In this review, the authors first summarize the current knowledge about the involvement of the ubiquitin-proteasome system in tumor development with the ubiquitin conjugation-regulated stability of p53, phosphatase and tensin homolog, and Myc protein as examples, then dissect the potential implications of ubiquitination-mediated immune checkpoints degradation in tumor microenvironment and immune responses, and finally discuss the effects of therapeutically targeting the ubiquitin-proteasome pathway on immunotherapy, with the goal of providing deep insights into the exploitation of more precise and effective combinational therapy against cancer.

Abstract PD2-08: Targeting of eIF4A1 along with anti-PD-L1 therapy limits lung metastases efficaciously in triple-negative breast cancer

Abstract Background: Triple-negative breast cancer (TNBC) is the most aggressive subtype of metastatic breast cancer with poor clinical prognosis. Currently used neoadjuvant chemotherapy for TNBC, such as taxanes, and/or anthracyclines demonstrate an initial treatment response but is often followed by drug resistance, tumor relapse, and high proclivity to develop metastases. There is an unmet need to develop effective combination therapies against metastatic TNBC (mTNBC). eIF4A1 is an mRNA helicase that help translate many oncogenic mRNAs including PD-L1 (through STAT1 translational regulation) that are involved in tumor growth, chemoresistance and metastases. Our prior studies pointed out that eIF4A1 is intricately linked to cancer stemness and drug resistance in TNBC. Emerging evidence has revealed that the tumor immune microenvironment (TIME) of TNBC do consist of mononuclear cells and lymphocytes. Combining chemotherapy with immune checkpoint inhibition had demonstrated a significant benefit for high-risk TNBC patients. In this study, we examine the efficacy of targeting eIF4A1 along with anti-PD-L1 therapy as an effective therapeutic strategy to limit cancer stemness, primary tumor progression and metastasis in an immunocompetent murine model of TNBC. Approach: Initially, we examined the human TNBC biospecimens and found that eIF4A1 protein level is upregulated in drug-resistant cases. STAT1 is an upstream regulator of PD-L1 and a downstream effector of eIF4A1. The protein level of STAT1 was significantly elevated as assessed by immunoblotting of human tumor lysates. In human TNBC cells, when eIF4A1 is pharmacologically or genetically targeted, PD-L1 was downregulated at the protein level. Based on this premise, we targeted eIF4A1 with the small molecule inhibitor, Rocaglamide A (RocA), along with anti-PD-L1 immunotherapy in orthotopically implanted 4T1 mouse TNBC tumors in BALB/c mice. The treatment arms were 1) Control (vehicle for RocA + control IgG) 2) RocA 3) RocA + anti-PD-L1 antibodies 4) Control IgG only 5) Anti-PD-L1 antibodies only with 10 mice in each group. Results: The combination treatment comprising of RocA and anti-PD-L1 antibodies worked out efficaciously as the primary tumor volume, wet tumor weight, bioluminescent tumor imaging and quantitation were significantly lower than the combination vehicle control. Furthermore, metastasis to the lungs were significantly impaired (1 out of 10 mice only had metastasis and that too it was small). On the contrary, ‘RocA single arm’ group had 6 out of 10 mice with lung metastasis. The lung metastases were observed in 4 out of 10 mice in the PD-L1 single arm and 6 out of 10 mice in control IgG single arm group. The RocA was tolerated well at 0.6 mg/kg with no significant change in the body weight and the liver and kidney function test values were within the normal range. Importantly, the combination treatment with RocA and PD-L1 was also tolerated well. Conclusions: The combination therapy involving RocA and PD-L1 had the significant impact in reducing lung metastases and may pave the way for phase I/II clinical trials. Citation Format: Dharmindra Dulal, Andrew Boring, Dayanidhi Raman. Targeting of eIF4A1 along with anti-PD-L1 therapy limits lung metastases efficaciously in triple-negative breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD2-08.

Proton Therapy, Magnetic Nanoparticles and Hyperthermia as Combined Treatment for Pancreatic BxPC3 Tumor Cells.

We present an investigation of the effects on BxPC3 pancreatic cancer cells of proton therapy combined with hyperthermia, assisted by magnetic fluid hyperthermia performed with the use of magnetic nanoparticles. The cells' response to the combined treatment has been evaluated by means of the clonogenic survival assay and the estimation of DNA Double Strand Breaks (DSBs). The Reactive Oxygen Species (ROS) production, the tumor cell invasion and the cell cycle variations have also been studied. The experimental results have shown that the combination of proton therapy, MNPs administration and hyperthermia gives a clonogenic survival that is much smaller than the single irradiation treatment at all doses, thus suggesting a new effective combined therapy for the pancreatic tumor. Importantly, the effect of the therapies used here is synergistic. Moreover, after proton irradiation, the hyperthermia treatment was able to increase the number of DSBs, even though just at 6 h after the treatment. Noticeably, the magnetic nanoparticles' presence induces radiosensitization effects, and hyperthermia increases the production of ROS, which contributes to cytotoxic cellular effects and to a wide variety of lesions including DNA damage. The present study indicates a new way for clinical translation of combined therapies, also in the vision of an increasing number of hospitals that will use the proton therapy technique in the near future for different kinds of radio-resistant cancers.

BAX as the mediator of C-MYC sensitizes acute lymphoblastic leukemia to TLR9 agonists

BackgroundThe prognosis of B-cell acute lymphoblastic leukemia (B-ALL) has improved significantly with current first-line therapy, although the recurrence of B-ALL is still a problem. Toll-like receptor 9 (TLR9) agonists have shown good safety and efficiency as immune adjuvants. Apart from their immune regulatory effect, the direct effect of TLR9 agonists on cancer cells with TLR9 expression cannot be ignored. However, the direct effect of TLR9 agonists on B-ALL remains unknown.MethodsWe discussed the relationship between TLR9 expression and the clinical characteristics of B-ALL and explored whether CpG 685 exerts direct apoptotic effect on B-ALL without inhibiting normal B-cell function. By using western blot, co-immunoprecipitation, immunofluorescence co-localization, and chromatin immunoprecipitation, we explored the mechanism of the apoptosis-inducing effect of CpG 685 in treating B-ALL cells. By exploring the mechanism of CpG 685 on B-ALL, the predictive biomarkers of the efficacy of CpG 685 in treating B-ALL were explored. These efficiencies were also confirmed in mouse model as well as clinical samples.ResultsHigh expression of TLR9 in B-ALL patients showed good prognosis. C-MYC-induced BAX activation was the key to the effect of CpG oligodeoxynucleotides against B-ALL. C-MYC overexpression promoted P53 stabilization, enhanced Bcl-2 associated X-protein (BAX) activation, and mediated transcription of the BAX gene. Moreover, combination therapy using CpG 685 and imatinib, a BCR-ABL kinase inhibitor, could reverse resistance to CpG 685 or imatinib alone by promoting BAX activation and overcoming BCR-ABL1-independent PI3K/AKT activation.ConclusionTLR9 is not only a prognostic biomarker but also a potential target for B-ALL therapy. CpG 685 monotherapy might be applicable to Ph− B-ALL patients with C-MYC overexpression and without BAX deletion. CpG 685 may also serve as an effective combinational therapy against Ph+ B-ALL.

An Effective Combination Therapy for the Treatment of Pediatric Monomorphic Post-transplant Lymphoproliferative Disorder With Plasmacytic Differentiation.

Post-transplant lymphoproliferative disorder (PTLD) is a complication of immunosuppressive therapy following solid organ or hematopoietic cell transplantation. Initial treatment typically includes a reduction of immunosuppression with or without rituximab. However, the optimal therapy for PTLD with plasmacytic differentiation is unclear. We present 3 cases of pediatric patients with plasmacytic PTLD. Two patients received a standard rituximab-based approach and relapsed, prompting additional chemotherapy. The third patient was treated with a novel regimen of bortezomib, dexamethasone, and daratumumab. This regimen was safe, well-tolerated, and resulted in a 2-year remission. Larger studies are needed to further explore this regimen.

Targeting the anaphase-promoting complex/cyclosome (APC/C) enhanced antiproliferative and apoptotic response in bladder cancer

Improving the chemotherapy sensitivity of bladder cancer is a current clinical challenge. It is critical to seek out effective combination therapies that include low doses of cisplatin due to its dose-limiting toxicity. This study aims to investigate the cytotoxic effects of the combination therapy including proTAME, a small molecule inhibitor, targeting Cdc-20 and to determine the expression levels of several APC/C pathway-related genes that may play a role in the chemotherapy response of RT-4 (bladder cancer) and ARPE-19 (normal epithelial) cells. The IC20 and IC50 values were determined by MTS assay. The expression levels of apoptosis-associated (Bax and Bcl-2) and APC/C-associated (Cdc-20, Cyclin-B1, Securin, and Cdh-1) genes were assessed by qRT-PCR. Cell colonization ability and apoptosis were examined by clonogenic survival experiment and Annexin V/PI staining, respectively. Low-dose combination therapy showed a superior inhibition effect on RT-4 cells by increasing cell death and inhibiting colony formation. Triple-agent combination therapy further increased the percentage of late apoptotic and necrotic cells compared to the doublet-therapy with gemcitabine and cisplatin. ProTAME-containing combination therapies resulted in an elevation in Bax/Bcl-2 ratio in RT-4 cells, while a significant decrease was observed in proTAME-treated ARPE-19 cells. Cdc-20 expression in proTAME combined treatment groups were found to be decreased compared to their control groups. Low-dose triple-agent combination induced cytotoxicity and apoptosis in RT-4 cells effectively. It is essential to evaluate the role of APC/C pathway-associated potential biomarkers as therapeutic targets and define new combination therapy regimens to achieve improved tolerability in bladder cancer patients in the future.

ATM inhibitor KU60019 synergistically sensitizes lung cancer cells to topoisomerase II poisons by multiple mechanisms

Type II topoisomerases (TOP2) poisons represent one class of the most successful and widely prescribed chemotherapeutics, which is frontline therapy for a myriad of systemic cancers and solid tumors, including lymphomas, leukemias, and lung cancer. Despite this, treatment with this class of drugs induces unwanted side effects (including cardiovascular morbidity and secondary malignancies). Additionally, the emergence of drug resistance also greatly compromises the clinical use of these drugs. To enhance therapeutic efficiency while lowering unwanted side effects, new insights into effective combination therapy are required. In this study we found that KU60019, a novel, and highly specific ATM kinase inhibitor interferes with the association of ATM with TOP2β and stabilizes TOP2β-DNA cleavage complex, thereby impairing the repair of TOP2 poison-induced DSBs and contributes to genome stability, leading to accelerated cell death. In H1299 as well as in A549 lung cancer cell lines, biologically, KU60019 combined with VP-16 (one of the TOP2 poisons) synergistically suppressed the growth of cells and survival and triggered a much higher apoptosis rate. In summary, we provide a proof-of-concept strategy that ATM inhibitors combined with TOP2 poison would synergistically suppresses lung cancer cell survival as well as reduce DNA damage responses, thus may lowering the possibility of cardiotoxicity and secondary malignancy linked to therapy.

Development of a Polymersome-Based Nanomedicine for Chemotherapeutic and Sonodynamic Combination Therapy.

In anticancer therapy, combination therapy has been suggested as an alternative to the insufficient therapeutic efficacy of single therapy. Among combination therapies, combination chemo- and photodynamic therapy are actively investigated. However, photodynamic therapy shows a limitation in the penetration depth of the laser. Therefore, sonodynamic therapy (SDT), using ultrasound instead of a laser as a trigger, is an upcoming strategy for deep tumors. Additionally, free drugs are easily degraded by enzymes, have difficulty in reaching the target site, and show side effects after systemic administration; therefore, the development of drug delivery systems is desirable for sufficient drug efficacy for combination therapy. However, nanocarriers, such as microbubbles, and albumin nanoparticles, are unstable in the body and show low drug-loading efficiency. Here, we propose polylactide (PLA)-poly (ethylene glycol) (PEG) polymersomes (PLs) with a high drug loading rate of doxorubicin (DOX) and verteporfin (VP) for effective combination therapy in both in vitro and in vivo experiments. The cellular uptake efficiency and cytotoxicity test results of VP-DOX-PLs were higher than that of single therapy. Moreover, in vivo biodistribution showed the accumulation of the VP-DOX-PLs in tumor regions. Therefore, VP-DOX-PLs showed more effective anticancer efficacy than either single therapy in vivo. These results suggest that the combination therapy of SDT and chemotherapy could show novel anticancer effects using VP-DOX-PLs.

A heuristic algorithm solving the mutual-exclusivity-sorting problem.

Binary (or Boolean) matrices provide a common effective data representation adopted in several domains of computational biology, especially for investigating cancer and other human diseases. For instance, they are used to summarize genetic aberrations-copy number alterations or mutations-observed in cancer patient cohorts, effectively highlighting combinatorial relations among them. One of these is the tendency for two or more genes not to be co-mutated in the same sample or patient, i.e. a mutual-exclusivity trend. Exploiting this principle has allowed identifying new cancer driver protein-interaction networks and has been proposed to design effective combinatorial anti-cancer therapies rationally. Several tools exist to identify and statistically assess mutual-exclusive cancer-driver genomic events. However, these tools need to be equipped with robust/efficient methods to sort rows and columns of a binary matrix to visually highlight possible mutual-exclusivity trends. Here, we formalize the mutual-exclusivity-sorting problem and present MutExMatSorting: an R package implementing a computationally efficient algorithm able to sort rows and columns of a binary matrix to highlight mutual-exclusivity patterns. Particularly, our algorithm minimizes the extent of collective vertical overlap between consecutive non-zero entries across rows while maximizing the number of adjacent non-zero entries in the same row. Here, we demonstrate that existing tools for mutual-exclusivity analysis are suboptimal according to these criteria and are outperformed by MutExMatSorting. https://github.com/AleVin1995/MutExMatSorting. Supplementary data are available at Bioinformatics online.

PH/GSH dual-responsive supramolecular nanomedicine for hypoxia-activated combination therapy.

Moderate oxygen (O2) supply and uneven distribution of oxygen at the tumor site usually hinder the therapeutic efficacy of hypoxia-activated prodrugs. In this report, we designed a ferrocene-containing supramolecular nanomedicine (PFC/GOD-TPZ) with the PEG corona and disulfide-bond cross-linked core to co-encapsulate 4-di-N-oxide tirapazamine (TPZ) and glucose oxidase (GOD). The PEG corona of PFC/GOD-TPZ could be weakly acidic tumor pH-responsively detached for an enhanced cellular internalization, while the disulfide-bond cross-linked core could be cleavaged by intracellular glutathione (GSH) to present a GSH-triggered drug-release behavior. Subsequently, the cascade reactions, including catalytic reactions among the released GOD, glucose, and O2 to generate H2O2 and the subsequent Fenton reaction between ferrocene and H2O2, occurred. With the depletion of O2, the non-toxic TPZ was activated and converted into the cytotoxic therapeutic agent benzotriazinyl (BTZ) radical under the exacerbated hypoxic microenvironment. Collectively, the PFC/GOD-TPZ provides a promising strategy for effective combination therapy of GOD-mediated starvation therapy, chemodynamic therapy (CDT), and hypoxia-activated chemotherapy (CT).

The bovine dialyzable leukocyte extract, immunepotent CRP, synergically enhances cyclophosphamide-induced breast cancer cell death, through a caspase-independent mechanism.

Breast cancer (BC) is one of the leading causes of cancer death worldwide. Cyclophosphamide (CTX) remains a mainstay in cancer therapy despite harmful adverse effects and cell death-resistances. To face this, combinational therapy of chemotherapies and immunotherapies has been proposed. IMMUNEPOTENT CRP (ICRP) is an immunotherapy that has cytotoxic effects in several cancer cells without affecting peripheral blood mononuclear cells (PBMC) and CD3+ cells. The aim of this study was to evaluate cytotoxicity, the type of cytotoxic effect, and several features involved in cell death induced by the combination of CTX with ICRP (ICRP+CTX) in breast cancer cells as well as their effect on healthy cells. For this purpose, human and murine breast cancer cells, MCF-7, MDA-MB-231 and 4T1, or PBMC were treated for 24 hours with ICRP, CTX or ICRP+CTX in different combination ratios for the assessment of cell death. Flow cytometry and microscopy were used to determine biochemical and morphological characteristics of cell death. Assays showed that ICRP in combination with CTX induce potentiated cell death manifested with morphological changes, loss of mitochondrial membrane potential, reactive oxygen species (ROS) production, and caspase activation. In addition, it was determined that ICRP+CTX-cell death is caspase-independent in all the breast cancer cells assessed. On the other hand, ICRP did not affect CTX-cytotoxicity in PBMC. For all the above, we can propose that the combination of ICRP with CTX an effective combination therapy, promoting their use even in tumoral cells with defects on proteins implicated in the apoptotic pathway.

Effective Combination Therapy with Human Amniotic Membrane Mesenchymal Stem Cells and Low-Level Laser Therapy in Wound Healing in Animal Models.

Introduction: Many studies have recognized the importance of new methods in wound healing. This study aims to investigate the healing effects of allograft extra embryonic mesenchymal stem cells (MSCs) with and without low-level diode laser irradiation when grafted into full-thickness skin defects in diabetic animal models. Methods: In this experimental study, in order to make the rats diabetic, we used an intra-peritoneal injection of streptozotocin. Human amniotic membrane derived mesenchymal stem cells (hAMSCs) were irradiated with a low-level diode laser. Two full-thickness excisions were made on the backs of the rats. Next, the rats were divided into the following groups: group 1: low-level laser (LLL) irradiated hAMSCs and group 2: hAMSCs alone transplanted into skin wound. Histopathologic, ultrasound and elasticity evaluations were performed 7, 14 and 21 days after grafting. Results: In the evaluated rats, epithelial formation was on day 7 and increased until day 14. On days 7, 14 and 21, the percentage of epithelial formation in the irradiated cell group was significantly higher than that in the cell group, so that, on day 21, the epithelium in this group completely covered the wound surface while in the control group the wound surface was still not completely covered. In terms of angiogenesis, on day 7, the irradiated cells were significantly lower than the cells. Also, the formation of collagen in the cellular hydrogel group could confirm the effectiveness of amniotic MSCs in collagen production and thus accelerate the wound healing process. In comparison with hAMSCs alone, irradiated hAMSCs increased the thickness and elasticity of the skin. Conclusion: Low-power laser along with MSCs can be effective in improving chronic wound condition in the animal model.

Deep learning-based multi-drug synergy prediction model for individually tailored anti-cancer therapies.

While synergistic drug combinations are more effective at fighting tumors with complex pathophysiology, preference compensating mechanisms, and drug resistance, the identification of novel synergistic drug combinations, especially complex higher-order combinations, remains challenging due to the size of combination space. Even though certain computational methods have been used to identify synergistic drug combinations in lieu of traditional in vitro and in vivo screening tests, the majority of previously published work has focused on predicting synergistic drug pairs for specific types of cancer and paid little attention to the sophisticated high-order combinations. The main objective of this study is to develop a deep learning-based approach that integrated multi-omics data to predict novel synergistic multi-drug combinations (DeepMDS) in a given cell line. To develop this approach, we firstly created a dataset comprising of gene expression profiles of cancer cell lines, target information of anti-cancer drugs, and drug response against a large variety of cancer cell lines. Based on the principle of a fully connected feed forward Deep Neural Network, the proposed model was constructed using this dataset, which achieved a high performance with a Mean Square Error (MSE) of 2.50 and a Root Mean Squared Error (RMSE) of 1.58 in the regression task, and gave the best classification accuracy of 0.94, an area under the Receiver Operating Characteristic curve (AUC) of 0.97, a sensitivity of 0.95, and a specificity of 0.93. Furthermore, we utilized three breast cancer cell subtypes (MCF-7, MDA-MD-468 and MDA-MB-231) and one lung cancer cell line A549 to validate the predicted results of our model, showing that the predicted top-ranked multi-drug combinations had superior anti-cancer effects to other combinations, particularly those that were widely used in clinical treatment. Our model has the potential to increase the practicality of expanding the drug combinational space and to leverage its capacity to prioritize the most effective multi-drug combinational therapy for precision oncology applications.

Efficacy of ceftazidime-avibactam in various combinations for the treatment of experimental osteomyelitis due to Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae

Optimal treatment of carbapenemase-producing Enterobacterales (CPE) bone infections is poorly defined. This study evaluated the efficacy of the novel beta-lactam-beta-lactamase inhibitor-ceftazidime-avibactam (CAZ-AVI)-with different antibiotic combinations in an experimental model of CPE osteomyelitis. KPC-99YC is a clinical strain of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae with intermediate susceptibility to meropenem (MIC 4 mg/L), gentamicin (MIC 0.25 mg/L), colistin (MIC 0.25 mg/L), fosfomycin (MIC 4 mg/L) and ceftazidime-avibactam (MIC 1 mg/L). Time-kill curves were performed at 4x MIC. Osteomyelitis was induced in rabbits by tibial injection of 2×108 CFU of KPC-99YC. Six groups started treatment 14 days later for 7 days: control, colistin, CAZ-AVI, CAZ-AVI plus gentamicin, CAZ-AVI plus colistin and CAZ-AVI plus fosfomycin. Antibiotic dosages were selected to simulate plasma concentrations obtained in humans. Treatment was evaluated according to bone cultures quantified in log10 CFU. In vitro, CAZ-AVI plus colistin or gentamicin were rapidly bactericidal in contrast with CAZ-AVI plus fosfomycin. In vivo, compared with controls, colistin alone (P=0.045) and CAZ-AVI alone or in combination significantly lowered bone bacterial counts (P < 0.001). Bone sterilisation was achieved in 67% and 100% of animals with combinations of CAZ-AVI plus colistin or gentamicin (P=0.001 and P < 0.001, respectively) whereas other treatments were no different from controls. CAZ-AVI plus gentamicin provided greater bone bacterial reduction than CAZ-AVI plus colistin (P=0.033). No CAZ-AVI-resistant strains emerged in treated rabbits, regardless of combination. CAZ-AVI plus gentamicin was the best effective combination therapy. Combinations with CAZ-AVI appear to be a promising treatment of KPC-producing Klebsiella pneumoniae osteomyelitis.

Abstract PR001: Mutant NPM1 hijacks transcriptional hub to maintain pathogenic gene programs and block differentiation in acute myeloid leukemia

Abstract Nucleophosmin (NPM1) is a ubiquitously expressed nucleolar protein with a wide range of functions including ribosome biogenesis, mRNA processing, and maintenance of genomic stability. In acute myeloid leukemia (AML), the terminal exon of NPM1 is often mutated (~30% of adult AMLs), changing the nucleolar localization signal into a nuclear export signal, which results in a shift of the protein to the cytoplasm (NPM1c). AMLs carrying this mutation have an aberrant expression of the HOXA genes, whose overexpression leads to leukemogenic transformation. The gene regulatory role of NPM1c has long been an enigma. Recently, it was shown that depletion or re-localization of the NPM1c protein into the nucleus [PG1] causes downregulation of the HOXA genes, leading to the speculation that NPM1c modulates transcription of HOXA genes. Here, we found NPM1c binds to chromatin and is located genome-wide at gene promoters and colocalized at active regions marked by H3K27ac in NPM1c leukemia cell lines and primary leukemia blasts. NPM1c clearly binds to known leukemia-driving genes - posterior HOXA, HOXB, and MEIS1/PBX3 genes as well as novel targets -IRX5 and NKX2-3. After PROTAC degradation of NPM1c, we observed a significant RNA polymerase II elongation defect genome-wide. The dramatic elongation defect is caused by the loss of the Super Elongation Complex (SEC) chromatin binding. Further tests suggest that loss of NPM1c leads to disruption of RNA polymerase II condensates as well as other direct transcriptional regulators of HOX genes - Menin and AFF4 through IDR interactions. We found that pulse PROTAC degradation of NPM1c leads to sustained differentiation with the loss of histone acetylation at NPM1c target loci. Further, NPM1c maintains the active chromatin state of target genes by antagonizing HDAC activity. Additionally, we found that NPM1c’s activation of the leukemia driving genes depends on the pre-established active chromatin state in the transformed hematopoietic stem and progenitor cells. NPM1c alone is not sufficient to activate these leukemia driving genes with heterochromatin marks accumulated. We also found that NPM1c binds to genomic regions that have been pre-bound by its export partner, XPO1. The XPO1 inhibitors Selinexor and Eltanexor can displace NPM1c from chromatin. The combination of clinical-grade XPO1 inhibitor eltanexor and Menin inhibitor MI-3454 displayed a strong synergy in inducing differentiation and reducing leukemia driving gene expression in the NPM1 mutated leukemia cell lines and PDX model, which promises to be an effective combination therapy for NPM1c leukemia patients. Citation Format: Xue Qing Wang, Dandan Fan, Yiman Liu, Qinyu Han, Jolanta Grembecka, Tomasz Cierpicki, Jianzhong Su, Shasha Chong, Liling Wan, Xiaotian Zhang. Mutant NPM1 hijacks transcriptional hub to maintain pathogenic gene programs and block differentiation in acute myeloid leukemia. [abstract]. In: Proceedings of the AACR Special Conference: Cancer Epigenomics; 2022 Oct 6-8; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_2):Abstract nr PR001.

Recent advances in the progress of immune checkpoint inhibitors in the treatment of advanced gastric cancer: A review.

Most patients with advanced gastric cancer were treated with palliative therapy, which had a poor curative effect and a short survival time. In recent years, the clinical research of immune checkpoint inhibitors in advanced gastric cancer has made a breakthrough and has become an important treatment for advanced gastric cancer. The modes of immune checkpoint inhibitors in the treatment of advanced gastric cancer include single drug, combined chemotherapy, radiotherapy, and multiple immune drug combination therapy, among which combination therapy shows better clinical efficacy, and a large number of trials are currently exploring more effective combination therapy programs. In this paper, the new clinical research progress of immune checkpoint inhibitors in the treatment of advanced gastric cancer is reviewed, with an emphasis on combination therapy.

Inhibition of mitochondrial translocase SLC25A5 and histone deacetylation is an effective combination therapy in neuroblastoma.

The mitochondrion is a gatekeeper of apoptotic processes, and mediates drug resistance to several chemotherapy agents used to treat cancer. Neuroblastoma is a common solid cancer in young children with poor clinical outcomes following conventional chemotherapy. We sought druggable mitochondrial protein targets in neuroblastoma cells. Among mitochondria-associated gene targets, we found that high expression of the mitochondrial adenine nucleotide translocase 2 (SLC25A5/ANT2), was a strong predictor of poor neuroblastoma patient prognosis and contributed to a more malignant phenotype in pre-clinical models. Inhibiting this transporter with PENAO reduced cell viability in a panel of neuroblastoma cell lines in a TP53-status-dependant manner. We identified the histone deacetylase inhibitor, suberanilohydroxamic acid (SAHA), as the most effective drug in clinical use against mutant TP53 neuroblastoma cells. SAHA and PENAO synergistically reduced cell viability, and induced apoptosis, in neuroblastoma cells independent of TP53-status. The SAHA and PENAO drug combination significantly delayed tumour progression in pre-clinical neuroblastoma mouse models, suggesting that these clinically advanced inhibitors may be effective in treating the disease.