Combined Approach Research Articles

Decoding the diagnostic and therapeutic potential of microbiota using pan-body pan-disease microbiomics

The human microbiome emerges as a promising reservoir for diagnostic markers and therapeutics. Since host-associated microbiomes at various body sites differ and diseases do not occur in isolation, a comprehensive analysis strategy highlighting the full potential of microbiomes should include diverse specimen types and various diseases. To ensure robust data quality and comparability across specimen types and diseases, we employ standardized protocols to generate sequencing data from 1931 prospectively collected specimens, including from saliva, plaque, skin, throat, eye, and stool, with an average sequencing depth of 5.3 gigabases. Collected from 515 patients, these samples yield an average of 3.7 metagenomes per patient. Our results suggest significant microbial variations across diseases and specimen types, including unexpected anatomical sites. We identify 583 unexplored species-level genome bins (SGBs) of which 189 are significantly disease-associated. Of note, the existence of microbial resistance genes in one specimen was indicative of the same resistance genes in other specimens of the same patient. Annotated and previously undescribed SGBs collectively harbor 28,315 potential biosynthetic gene clusters (BGCs), with 1050 significant correlations to diseases. Our combinatorial approach identifies distinct SGBs and BGCs, emphasizing the value of pan-body pan-disease microbiomics as a source for diagnostic and therapeutic strategies.

Short Peptides as Powerful Arsenal for Smart Fighting Cancer

Short peptides have been coming around as a strong weapon in the fight against cancer on all fronts—in immuno-, chemo-, and radiotherapy, and also in combinatorial approaches. Moreover, short peptides have relevance in cancer imaging or 3D culture. Thanks to the natural ‘smart’ nature of short peptides, their unique structural features, as well as recent progress in biotechnological and bioinformatics development, short peptides are playing an enormous role in evolving cutting-edge strategies. Self-assembling short peptides may create excellent structures to stimulate cytotoxic immune responses, which is essential for cancer immunotherapy. Short peptides can help establish versatile strategies with high biosafety and effectiveness. Supramolecular short peptide-based cancer vaccines entered clinical trials. Peptide assemblies can be platforms for the delivery of antigens, adjuvants, immune cells, and/or drugs. Short peptides have been unappreciated, especially in the vaccine aspect. Meanwhile, they still hide the undiscovered unlimited potential. Here, we provide a timely update on this highly active and fast-evolving field.

Bimetallic AgCo Nanoparticle Synthesis via Combinatorial Nanosecond Laser‐Induced Dewetting of Thin Films

Herein, a combinatorial approach is developed to conduct high‐throughput studies on the nanosecond pulsed laser‐induced dewetting phenomenon of bilayer Ag–Co metallic thin films. Laser irradiation results in the spontaneous rupture of these films in nanosecond timescale, forming bimetallic nanoparticles (NPs) through intermediate stages of hole formation and bicontinuous nanostructures. This approach utilizes bilayer thin films with thickness gradients in both Ag and Co layers (referred to as bigradient samples) while maintaining a constant overall thickness. The laser irradiation on such bigradient bilayer films facilitates control on Ag and Co ratio in the thin films, thus enabling material libraries of Ag–Co NPs covering a large compositional variation. The evolution of NPs with a correlation between NP diameter and interparticle spacings is further studied. The study reveals monotonic increase in NP size and interparticle spacing in Co/Ag bilayer arrangement, while an increase and subsequent decrease in the NP size is observed at 50% Ag in Ag/Co bigradient films. A transition from intermediate stage hole formation to bicontinuous nanostructures with changing composition is also observed. These changes in intermediate stage morphologies and dewetting mechanism are attributed to variation of the free energy of the bilayer system dominated by intermolecular interaction forces.

Engineered Tools to Advance Cell Transplantation in the Nervous System Towards a Clinical Reality

Abstract Purpose of the Review The goal of this review is to highlight engineered tools for overcoming challenges in cell survival and engraftment for tissue regeneration and mitigation of neuropathic pain following cell transplantation for neural applications. Recent Findings There is a growing body of evidence supporting the safety of cell transplantation for the treatment of injuries to the brain, spinal cord, and peripheral nerves. However, the efficacy of these cell therapies is inconclusive, and the path forward remains unclear due to a lack of evidence of transplant survival and engraftment. Engineered biomaterials offer promising pre-clinical evidence of enhanced survival and engraftment of cells transplanted within the nervous system. Biomaterials have been used alone or in combination with drug and gene delivery to direct cell transplant outcomes and represent a future direction for clinical evaluation given pre-clinical survival rates that may eliminate reliance on systemic immunosuppression. Summary Biomaterial approaches under pre-clinical evaluation can support cell survival, localize cells in the injured tissue where they are needed, and enable tissue engraftment, yet have not advanced towards the clinic. Existing biomaterials provide passive support of survival during delivery and/or place a premium on supporting cell engraftment, but active remediation of tissue-local inflammation that inhibits transplant survival and leads to neuropathic pain has seen very little advancement in recent years. Combinatorial approaches capable of addressing challenges in both survival and engraftment of cell transplants in the nervous system represent an area for significant growth in the coming years.

Systemic Codelivery of Thymoquinone and Doxorubicin by Targeted Mesoporous Silica Nanoparticle Sensitizes Doxorubicin-Resistant Breast Cancer by Interfering between the MDR1/P-gp and miR 298 Crosstalk.

Multi drug resistance (MDR) in breast carcinoma still poses a significant impairment to successful chemotherapy. As the arsenal of anticancer agents increases with improved preclinical methods, the growth of therapeutic drug combinations is now unprecedented. The malignancies addressed by mono drugs often fail to limit cancer progression, resulting in resistant cancer, thereby offering combinatorial therapies a terrific edge over monodrug regimes. However, the selection of drug combinations required enough preliminary evidence for their synergistic effect. The fundamental mechanisms of MDR to chemotherapeutics are associated with the overexpression of membrane efflux pumps, alternations in drug targets, and increased drug metabolism. Unfortunately, it is very difficult for drugs to overcome resistance produced on their own or by another different drug action. In this context, herein, we report a simple delivery system for coencapsulation and intracellular codelivery of dual-drug thymoquinone (TQ) and doxorubicin (DOX) to resensitize DOX-resistant MDA MB231 cell line (231 R). The 231 R cell line developed in our lab showed an enhanced expression of the ATP-binding cassette (ABC) transporters P-gp1/MDR-1 and a declined miR-298 expression. The present delivery system is based on amine-functionalized mesoporous silica nanoparticles (MSNs), in which the side chain amine functional group was used to react with the carbonyl group of TQ, which acts as a pro-drug system (TQ-MSN) to release TQ and DOX simultaneously. DOX was encapsulated later into the above TQ-MSN by a simple diffusion method. The drugs containing MSNs were further coated with a hyaluronic acid-conjugated PEG-PLGA polymer (HA@TQ-DOX-MSN). This simple nanostrategy interferes with the MDR-1/miR-298 cross-talk, thereby allowing a significant reduction in drug efflux from the cell and highlighting a promising nanotechnology-based combinatorial delivery approach in managing breast cancer chemoresistance.

HCMV detection in Asian gastric cancer RNA-seq data sets and clinical validation in Indian GC patients reveals the HCMV-GC specific gene signatures.

Gastric cancer (GC) prevalence is very high in the Asian population. Oncogenic viruses play a crucial role in the progression of different types of cancers. Through reanalysis of clinical RNA-seq data sets derived from Asian GC patients, this study identified the presence of human cytomegalovirus (HCMV) in Asian GC tumors, next to the well-studied association of EBV. Clinical recruitment of the Indian GC cohort and screening for HCMV presence identified a 14.28% occurrence, similar to that observed in the bioinformatics analysis. A combinatorial approach of rank-based meta-analysis and ranking of groups based on an expectation-maximization algorithm identified that the upregulated LINC02864 and MAGEA10 correlated with poor survival of GC patients and downregulated tumor suppressor genes enriching for gastric acid secretion pathway to be associated with HCMV-positive GC patients, revealing the progressive role of HCMV infection in GC. Genes that discriminate between different stages of GC were identified through feature selection implemented in a machine-learning approach. LTF and KLK10 expressions were found to be specifically dysregulated by HCMV and can also indicate the GC stages. The results of this study will guide future studies to identify the functional role of these genes in the HCMV-associated GC.IMPORTANCENearly 75% of gastric cancer (GC) cases reported globally are from the Asian population. Most existing public databases, such as TCGA, comprise only a fractional portion of data derived from Asian ancestry. This study identified EBV and human cytomegalovirus (HCMV)'s higher detection in GC patients. The presence and role of EBV associated with GC are well-known, and the observation of HCMV prompted us to validate the findings in a small cohort of 40 Indian GC patients. We observed a 14.28% occurrence of HCMV in the Indian cohort, similar to that observed from next-generation sequencing. A combinatorial approach of rank-based meta-analysis and ranking of groups based on an expectation-maximization algorithm identified that the upregulated LINC02864 and MAGEA10 correlated with poor survival of GC patients and downregulated tumor suppressor genes enriching for gastric acid secretion pathway to be associated with HCMV-positive GC patients, revealing the progressive role of HCMV infection in GC.

Abstract C018: Targeting KRAS inhibitor resistance by ferroptosis induction in PDAC

Abstract KRAS inhibitors (KRASi) have shown promising antitumor activity in PDAC patients; however, intrinsic and acquired resistance will likely preclude durable monotherapy responses in the clinic. Genetic and pharmacologic targeting of the KRAS pathway is associated with transcriptional and metabolic adaptations, including epithelial-to-mesenchymal transition (EMT) and dysregulated iron homeostasis that contribute to resistance. Therapy resistant mesenchymal cancer cells have a high reliance on iron that increases their susceptibility to ferroptosis, an iron-dependent form of cell death characterized by generation of lipid reactive oxygen species (ROS). We hypothesize that KRASi resistance characterized by EMT can be overcome by ferroptosis induction in PDAC. Here, we use in vitro and ex vivo PDAC models and transcriptomic and proteomic profiling to define critical ferroptotic liabilities in KRASi-treated PDAC. First, we evaluated the effect of inhibiting different ferroptosis defense mechanisms (e.g. SLC7A11, GPX4, FSP1) using newly developed ferroptosis inducers (FINs) in a panel of epithelial and mesenchymal PDAC cells. Mesenchymal cells were more sensitive to ferroptosis induction compared to epithelial cells. Since ferroptotic death is regulated by multiple ferroptosis defense pathways, and in general PDAC are relatively resistant to ferroptosis induction, it is unlikely that a single ferroptosis inducer will be successful. Therefore, targeting multiple nodes with FINs in a combinatorial approach may lead to a more pronounced effect. Combination GPX4 and SLC7A11 inhibition and GPX4 and FSP1 inhibition were the most effective combinations compared to respective monotherapies. Next, we evaluated if combination of KRASi and ferroptosis induction is synergistic. Transcriptomic analysis of KRAS-mutant PDAC cell lines sensitive or with a priori resistance to KRASi revealed that EMT-related gene sets were upregulated in KRASi resistant cell lines. Quantitative proteomics revealed that PDAC cells treated long-term with KRASi undergo EMT and likewise long-term KRASi in in vivo PDAC models induces EMT. A KRASi-anchored CRISPR/Cas9 screen showed that sgRNAs targeting GPX4 dropped out in multiple cell lines indicating that ferroptosis induction may be synergistic upon KRAS inhibition. Remarkably, KRASi induced an increase of lipid peroxidation levels in PDAC cells which was rescued with antioxidant ferrostatin-1. We also observed that previously generated KRASi resistant cells were more sensitive to GPX4 inhibition. Combination of GPX4 inhibitor with KRASi led to a synergistic effect on cell viability and a significantly higher level of lipid peroxidation compared to monotherapy. These findings highlight the importance of investigating ferroptosis induction as a novel strategy to overcome therapeutic resistance in KRAS-mutant PDAC. We aim to further evaluate these combinations in vivo to determine the best combinatorial strategies in PDAC to prevent or circumvent KRASi resistance. Citation Format: Aparna Padhye, Qijia Yu, Nicole Sindoni, Huan Zhang, Julien Dilly, Hanrong Feng, Andrew Aguirre, Joseph Mancias. Targeting KRAS inhibitor resistance by ferroptosis induction in PDAC [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 C018.

Abstract C028: Challenging PDAC adaptability: Uncovering therapeutic vulnerabilities in APE1 DNA repair mechanisms

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a therapeutically challenging malignancy notorious for its resilience to therapeutic strategies and ability to thrive under extreme conditions. The cancer's inherent ability to adaptively resist treatments underscores the need for novel and combinatorial therapeutic approaches. Our research focuses on elucidating the role of Apurinic-apyrimidinic endonuclease/Redox effector factor 1 (APE1/Ref-1), a critical multifunctional protein in PDAC pathobiology. APE1 serves two essential functions: as the principal endonuclease in the base excision repair (BER) pathway for DNA repair and as a redox regulator of transcription factors essential for cancer cell proliferation. While the therapeutic targeting of APE1’s redox function has been effective and continues to yield significant advances, the development of treatments aimed at its DNA repair function has proven more challenging with comparatively limited progress. Since standard PDAC treatment regimens involve DNA damaging agents potentially repaired via BER and APE1, we engineered three mutant cell lines with knock-in mutations resulting in a reduction of APE1’s BER activity while maintaining full redox activity. Biochemical evaluations confirmed the effects of the mutation, revealing a 30-fold reduction in DNA repair capacity. Surprisingly, with respect to growth and proliferation, the mutant and wild-type cell lines behaved similarly. Analyses of cytotoxic vulnerabilities revealed similar findings with the mutant lines exhibiting minimal phenotypic differences in sensitivity when challenged with cytotoxic and DNA damaging agents in proliferation-based assays. These findings led us to posit that the mutant cell lines were relying on compensatory DNA repair pathways which were providing sufficient compensation for the decrease in APE1 activity. We further hypothesized that the cell lines may still have hidden, long-term deficiencies in DNA damage processing which are not apparent during the initial stress response. Subsequent colony formation assays revealed that the mutant cell lines do exhibit poor long-term survival even after only short-term exposure to DNA damage. In vivo orthotopic mouse model experiments further corroborated these findings, showing a significant reduction in tumor size and decreased metastasis to the lungs and liver in mutant cell lines compared to wild-type controls. While APE1 is the primary endonuclease in the BER pathway, studies have demonstrated APE1-independent BER in rare, specific contexts. We are probing the hypothesis that these APE1-independent BER pathways function as the compensatory mechanism safeguarding these cells in short-term stress situations. Identifying and characterizing these backup pathways will not only offer a better understanding of APE1’s DNA repair capabilities within PDAC but will also provide a better understanding of how DNA repair mechanisms can be therapeutically targeted for novel therapeutic options or combinations. This opens the path to enhance standard of care treatments such as FOLFIRINOX. Citation Format: Eyram K Kpenu, Randall Wireman, Mahmut Mijiti, Silpa Gampala, Melissa L Fishel, Mark R Kelley. Challenging PDAC adaptability: Uncovering therapeutic vulnerabilities in APE1 DNA repair mechanisms [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 C028.

Characterization of DNA damage repair pathway utilization in high-grade serous ovarian cancers yields rational therapeutic approaches

While poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) have improved the prognosis of ovarian high-grade serous carcinoma (HGSC) tumors that are homologous recombination (HR) deficient (HRD), new therapeutic strategies are needed for tumors that are HR proficient (HRP) because they demonstrate greater resistance to current treatments and thus have poorer clinical outcomes. Additionally, clinical precautionary statements regarding potential risks associated with PARPi, such as myelodysplastic syndrome, highlight the need for combinatorial approaches that can lessen the dose and duration of PARPi treatment to reduce toxicities. Here, we evaluated DNA double-strand damage repair pathways in HRD and HRP ovarian cancer cell lines and found that in HRD cell lines, PARPi therapy reduced non-homologous end joining (NHEJ)-mediated repair, specifically due to decreased theta-mediated end-joining. The combination of PARPi with ATM serine/threonine kinase inhibitor (ATMi) suppressed both NHEJ and HR pathways in HRD and HRP cell lines, with synergistic increases in apoptosis and decreases in cell viability and colony formation. Interestingly, PARPi plus ATMi also decreased NF-κB p65 phosphorylation, which was not observed when PARPi was combined with inhibition of the ATR kinase (ATRi). These findings indicate that PARPi plus ATMi is a promising strategy for HGSC independent of underlying tumor HR status.

Glioma nanotherapy: Unleashing the synergy of dual-loaded DIM and TMZ

Glioblastoma multiforme (GBM) is a highly aggressive form of primary brain tumor in adults, which unfortunately has an abysmal prognosis and poor survival rates. The reason behind the poor success rate of several FDA-approved drug is mainly attributed to insufficient drug distribution to the tumor site across the blood–brain barrier (BBB) and induction of resistance. In this study, we have developed a novel nanotherapeutic approach to achieve our goal. PLGA-based nanoencapsulation of both Temozolomide (TMZ) and EGFR inhibitor 3,3′-diindoyl methane (DIM) in a combinatorial approach enhances the delivery of them together. Their synergistic mode of actions, significantly enhances the cytotoxic effect of TMZ in vitro and in vivo. Moreover, the dual-loaded nanoformulation works more efficiently on DNA damage and apoptosis, resulting in a several-fold reduction in tumor burden in vivo, systemic drug toxicity, and increased survival. These findings suggest the preclinical potential of this new treatment strategy.

Exploring the Therapeutic Implications of Co-Targeting the EGFR and Spindle Assembly Checkpoint Pathways in Oral Cancer.

Head and neck cancer (HNC), the sixth most common cancer worldwide, is increasing in incidence, with oral squamous cell carcinoma (OSCC) as the predominant subtype. OSCC mainly affects middle-aged to elderly males, often occurring on the posterior lateral border of the tongue, leading to significant disfigurement and functional impairments, such as swallowing and speech difficulties. Despite advancements in understanding OSCC's genetic and epigenetic variations, survival rates for advanced stages remain low, highlighting the need for new treatment options. Primary treatment includes surgery, often combined with radiotherapy (RT) and chemotherapy (CT). Cetuximab-based chemotherapy, targeting the overexpressed epidermal growth factor receptor (EGFR) in 80-90% of HNCs, is commonly used but correlates with poor prognosis. Additionally, monopolar spindle 1 (MPS1), a spindle assembly checkpoint (SAC) component, is a significant target due to its role in genomic fidelity during mitosis and its overexpression in several cancers. This review explores EGFR and MPS1 as therapeutic targets in HNC, analyzing their molecular mechanisms and the effects of their inhibition on cancer cells. It also highlights the promise of combinatorial approaches, such as microtubule-targeting agents (MTAs) and antimitotic agents, in improving HNC therapies, patient outcomes, and survival rates.

Combinatorial iterative method for metabolic engineering of Yarrowia lipolytica: Application for betanin biosynthesis

Combinatorial library-based metabolic engineering approaches allow lower cost and faster strain development. We developed a genetic toolbox EXPRESSYALI for combinatorial engineering of the oleaginous yeast Yarrowia lipolytica. The toolbox enables consecutive rounds of engineering, where up to three combinatorially assembled gene expression cassettes can be integrated into each yeast clone per round. The cassettes are integrated into distinct intergenic sites or an open reading frame of a target gene if a simultaneous gene knockout is desired. We demonstrate the application of the toolbox by optimizing the Y. lipolytica to produce the red beet color betanin via six consecutive rounds of genome editing and screening. The library size varied between 24 and 360. Library screening was facilitated by automated color-based colony picking. In the first round, betanin pathway genes were integrated, resulting in betanin titer of around 20 mg/L. Through the following five consecutive rounds, additional biosynthetic genes were integrated, and the precursor supply was optimized, resulting in a titer of 70 mg/L. Three beta-glucosidases were deleted to prevent betanin deglycosylation, which led to a betanin titer of 130 mg/L in a small scale and a titer of 1.4 g/L in fed-batch bioreactors. The EXPRESSYALI toolbox can facilitate metabolic engineering efforts in Y. lipolytica (available via AddGene Cat. Nr. 212682–212704, Addgene kit ID # 1000000245).

Metabolic engineering of Saccharomyces cerevisiae for enhanced taxadiene production

BackgroundMetabolic engineering enables the sustainable and cost-efficient production of complex chemicals. Efficient production of terpenes in Saccharomyces cerevisiae can be achieved by recruiting an intermediate of the mevalonate pathway. The present study aimed to evaluate the engineering strategies of S. cerevisiae for the production of taxadiene, a precursor of taxol, an antineoplastic drug.ResultSCIGS22a, a previously engineered strain with modifications in the mevalonate pathway (MVA), was used as a background strain. This strain was engineered to enable a high flux towards farnesyl diphosphate (FPP) and the availability of NADPH. The strain MVA was generated from SCIGS22a by overexpressing all mevalonate pathway genes. Combining the background strains with 16 different episomal plasmids, which included the combination of 4 genes: tHMGR (3-hydroxy-3-methylglutaryl-CoA reductase), ERG20 (farnesyl pyrophosphate synthase), GGPPS (geranyl diphosphate synthase) and TS (taxadiene synthase) resulted in the highest taxadiene production in S. cerevisiae of 528 mg/L.ConclusionOur study highlights the critical role of pathway balance in metabolic engineering, mainly when dealing with toxic molecules like taxadiene. We achieved significant improvements in taxadiene production by employing a combinatorial approach and focusing on balancing the downstream and upstream pathways. These findings emphasize the importance of minor gene expression modification levels to achieve a well-balanced pathway, ultimately leading to enhanced taxadiene accumulation.

Efficacy of PARP inhibitor therapy after targeted BRAF/MEK failure in advanced melanoma

Modern advancements in targeted therapy and immunotherapy have significantly improved survival outcomes for advanced melanoma; however, there remains a need for novel approaches to overcome disease progression and treatment resistance. In recent years, PARPi therapy has shown great promise both as a single regimen and in combination with other therapeutics in melanoma. Here, we describe three unique cases of advanced BRAF V600 mutated melanoma that progressed on targeted BRAF/MEK agents that subsequently exhibited partial to near-complete responses to combinatory PARPi and BRAF/MEK inhibitors. This highlights both a potential synergy underlying this combinatory approach and its efficacy as a treatment option for patients with advanced melanoma refractory to targeted and/or immunotherapies. Prospective clinical trials are needed to explore this synergic effect in larger melanoma cohorts to investigate this combination for treating refractory advanced melanoma.

Anti-neoplastic Properties of Boswellic Acids and their Novel Semi-synthetic Analogs: In vitro, In vivo and Clinical Evidence

Introduction: Recently, Boswellia gum resin extract has been shown to exhibit therapeutic properties against multiple inflammatory illnesses, comprising arthritis, asthma, diabetes, inflammatory bowel disease, and different malignancies. There are growing shreds of evidence that Boswellia extracts and their phytoconstituents could be used in adjuvant and combinatorial chemotherapeutic approaches for the management and prevention of cancer. Aim: The principal objective of this comprehensive investigation is to offer up-to-date and in-depth insights into the anticancer potential of boswellic acids along with their semisynthetic analog that are novel and preventive/therapeutic substitutes for the management of cancer and inflammatory diseases due to their strong potential. Materials and Methods: In the course of this review, a comprehensive compilation of In-vitro, Invivo, and clinical evidence on the antineoplastic potential of boswellic acids was assembled through systematic computerized searches utilizing platforms such as Google Scholar, PubMed, Sci-Hub, and Research Gate. Result: Boswellic acids, the key compounds found in the resin of nearly all the species of the Boswellia plant, have been reported to exhibit therapeutic effects by modulating various targets in different disease conditions. Moreover, semisynthetic derivatives of boswellic acids show strong cytotoxic effects, particularly those with cyanoenone moieties, endoperoxides, and hybrids, which exhibit enhanced potency. Conclusion: In this review, we have sincerely highlighted the effectiveness of novel boswellic acids as alternative preventive and therapeutic agents for the treatment of cancer and inflammatory conditions. Their strong anticancer potential could provide a basis for promising future direction to develop potent anticancer drugs for human malignancies.

The type of DNA damage response after decitabine treatment depends on the level of DNMT activity.

Decitabine and azacytidine are considered as epigenetic drugs that induce DNA methyltransferase (DNMT)-DNA crosslinks, resulting in DNA hypomethylation and damage. Although they are already applied against myeloid cancers, important aspects of their mode of action remain unknown, highly limiting their clinical potential. Using a combinatorial approach, we reveal that the efficacy profile of both compounds primarily depends on the level of induced DNA damage. Under low DNMT activity, only decitabine has a substantial impact. Conversely, when DNMT activity is high, toxicity and cellular response to both compounds are dramatically increased, but do not primarily depend on DNA hypomethylation or RNA-associated processes. By investigating proteome dynamics on chromatin, we show that decitabine induces a strictly DNMT-dependent multifaceted DNA damage response based on chromatin recruitment, but not expression-level changes of repair-associated proteins. The choice of DNA repair pathway hereby depends on the severity of decitabine-induced DNA lesions. Although under moderate DNMT activity, mismatch (MMR), base excision (BER), and Fanconi anaemia-dependent DNA repair combined with homologous recombination are activated in response to decitabine, high DNMT activity and therefore immense replication stress induce activation of MMR and BER followed by non-homologous end joining.

Selenium Nanoparticles Synergize with a KRAS Nanovaccine against Breast Cancer.

Selenium (Se) is an element crucial for human health, known for its anticancer properties. Although selenium nanoparticles (SeNPs) have shown lower toxicity and higher biocompatibility than other Se compounds, bare SeNPs are unstable in aqueous solutions. In this study, several materials, including bovine serum albumin (BSA), chitosan, polymethyl vinyl ether-alt-maleic anhydride, and tocopherol polyethylene glycol succinate, are explored to develop stable SeNPs and further evaluate their potential as candidates for cancer treatment. All optimized SeNP are spherical, <100nm, and with a narrow size distribution. BSA-stabilized SeNPs produced under acidic conditions present the highest stability in medium, plasma, and at physiological pH, maintaining their size ≈50-60nm for an extended period. SeNPs demonstrate enhanced toxicity in cancer cell lines while sparing primary human dermal fibroblasts, underscoring their potential as effective anticancer agents. Moreover, the combination of BSA-SeNPs with a nanovaccine results in a strong tumor growth reduction in an EO771 breast cancer mouse model, demonstrating a three-fold decrease in tumor size. This synergistic anticancer effect not only highlights the role of SeNPs as effective anticancer agents but also offers valuable insights for developing innovative combinatorial approaches using SeNPs to improve the outcomes of cancer immunotherapy.

Reductive alkyl-alkyl coupling from isolable nickel-alkyl complexes.

The selective cross-coupling of two alkyl electrophiles to construct complex molecules remains a challenge in organic synthesis1,2. Known reactions are optimized for specific electrophiles and are not amenable to interchangeably varying electrophilic substrates that are sourced from common alkyl building blocks, such as amines, carboxylic acids and halides3-5. These limitations restrict the types of alkyl substrate that can be modified and, ultimately, the chemical space that can be explored6. Here we report a general solution to these limitations that enables a combinatorial approach to alkyl-alkyl cross-coupling reactions. This methodology relies on the discovery of unusually persistent Ni(alkyl) complexes that can be formed directly by oxidative addition of alkyl halides, redox-active esters or pyridinium salts. The resulting alkyl complexes can be isolated or directly telescoped to couple with a second alkyl electrophile, which represent cross-selective reactions that were previously unknown. The utility of this synthetic capability is showcased in the rapid diversification of amino acids, natural products, pharmaceuticals and drug-like building blocks by various combinations of dehalogenative, decarboxylative or deaminative coupling. In addition to a robust scope, this work provides insights into the organometallic chemistry of synthetically relevant Ni(alkyl) complexes through crystallographic analysis, stereochemical probes and spectroscopic studies.

Design of Oxidation-Resistant Alloys Using Combinatorial Approaches with Chemically Graded Materials

This work introduces a new high-throughput method to characterize the oxidation behavior of chemically graded Ni-based alloys in order to feed databases destined to numerical metallurgy approaches. A Ni–wCr–3Al (w ∈ [0, 30]) chemically graded material was obtained from two homogeneous samples by a diffusion couple method at 1300 °C for 100 h. The composition range was selected in order to observe the three types of oxidation behavior identified in the reference work of Giggins and Pettit (Giggins and Pettit in Journal of The Electrochemical Society 118:1782, 1971). The excellent agreement between simulated and experimental diffusion profiles validated the experimental method used to manufacture the chemically graded material (CGM). The CGM was then oxidized at 1200 °C in air. Surface and cross-section characterization was conducted by SEM/EDS and Raman spectroscopy to identify the oxides formed on the CGM. To accelerate the Raman characterization treatment, a method linking principal component analysis and K-means unsupervised clustering algorithm was developed. It allowed for the identification of the oxide type without peak indexation issues and is well suited for CGM. These results show that results similar to well-recognized reference experiments (Giggins and Pettit in Journal of The Electrochemical Society 118:1782, 1971) can be achieved using only one CGM.

IBFFM Low-Lying States and Their Spin- Dependent Level Densities For Even-A Nuclei Associated with SU(6) Approximation and It’s O(6) Dynamical Symmetry of IBM

Objective: in this paper spin dependent level density dependence from dynamical, exchange particle-quasiparticle interactions and residual proton-neutron interactions are investigated. Theoretical framework: in the interacting boson-fermion-fermion model(IBFFM) for odd-odd nuclei 196Au the low-lying states and their densities are calculated for π d 3/2 , π d 5/2 , π s ½ , π h11/2 proton quasiparticles and ν p1/2, ν f5/2, ν p3/2, ν f7/2, ν i13/2 neutron quasiparticles and ν p1/2, ν f5/2, ν p3/2, ν f7/2, ν i13/2 neutron quasiparticles states, coupled to the IBM core in Su(6) approximation and it's O(6) dynamical symetry of interacting boson model (IBM). Method: we also applied cutting bosons and fermions space and investigated their impacts on spin dependent level density. The results are shown graphically and compared to the previous combinatorial, thermodynamic and spectral distribution approaches for 132Pr, 244 am and 114 Cd. Results and discussion: the IBFFM low-lying states up to 2 MeV are exactely in acordance with experimentala data. The IBFFM spin–dependent level densities can be well accounted by bethe and modified spin distribution formula. For small changes of dynamical, exchange and residual interactions we have a small changes in the spin-dependent level density of states. Research implications: the complex collective features and interplay between collective and quasiparticle degrees of freedom do not influence sizeable the IBFFM spin-dependent level density distribution. Originality/value: this study contributes to the literature of IBFFM low-lying states and their spin- dependent level densities for even-A nuclei.