Pharmacological boosting of cGAS activation sensitizes chemotherapy by enhancing antitumor immunity.

Enhancing chemosensitivity is one of the largest unmet medical needs in cancer therapy. Cyclic GMP-AMP synthase (cGAS) connects genome instability caused by platinum-based chemotherapeutics to type I interferon (IFN) response. Here, by using a high-throughput small-molecule microarray-based screening of cGAS interacting compounds, we identify brivanib, known as a dual inhibitor of vascular endothelial growth factor receptor and fibroblast growth factor receptor, as a cGAS modulator. Brivanib markedly enhances cGAS-mediated type I IFN response in tumor cells treated with platinum. Mechanistically, brivanib directly targets cGAS and enhances its DNA binding affinity. Importantly, brivanib synergizes with cisplatin in tumor control by boosting CD8+ T cell response in a tumor-intrinsic cGAS-dependent manner, which is further validated by a patient-derived tumor-like cell clusters model. Taken together, our findings identify cGAS as an unprecedented target of brivanib and provide a rationale for the combination of brivanib with platinum-based chemotherapeutics in cancer treatment.

Naringin: antitumor potential in silico and in vitro on bladder cancer cells

Introduction: Urothelial carcinoma is a significant public health problem. Transitional cell carcinoma (TCC) is the most common subtype, accounting for approximately 90 % of all bladder cancers. Chemotherapeutic protocols have been studied, but some present high toxicity and low tolerability. Naringin is a polyphenolic compound found mainly in citrus fruits, which antitumor activity has been studied in several types of cancer. However, there is little information about naringin effects on bladder cancer. This study aimed to evaluate the antitumor potential of naringin in silico and in vitro using two bladder cancer cell lines. Method: In silico analysis was carried out by PASS Online software. In vitro , the effects of naringin treatment (12.5 - 400 µM) were evaluated regarding its cytotoxicity, clonogenic survival, morphological alterations, cell cycle progression, migration, and mutagenicity Results: In silico analyses predicted antitumor activity through several mechanisms of action. In vitro results showed naringin presented cytotoxic effects, reduced the number of colonies, inhibited cell migration, and changed the morphology and cell cycle progression of the two cell lines evaluated. However, naringin did not present mutagenic effects. Conclusions: Naringin has antiproliferative activity and is a promising candidate for bladder cancer treatment.(AU)

Introducción: El carcinoma urotelial es un problema de salud pública importante. El carcinoma de células de transición es el subtipo más común y representa aproximadamente el 90 % de todos los cánceres de vejiga. Se han estudiado protocolos quimioterapéuticos, pero algunos presentan alta toxicidad y baja tolerabilidad. La naringina es un compuesto polifenólico que se encuentra principalmente en los cítricos, cuya actividad antitumoral se ha estudiado en varios tipos de cáncer. Sin embargo, hay poca información sobre los efectos de la naringina en el cáncer de vejiga. Este estudio tuvo como objetivo evaluar el potencial antitumoral de la naringina in silico e in vitro utilizando dos líneas celulares de cáncer de vejiga. Método: El análisis in silico se llevó a cabo mediante el software PASS Online. In vitro, se evaluaron los efectos del tratamiento con naringina (12,5 - 400 µM) en cuanto a su citotoxicidad, supervivencia clonogénica, alteraciones morfológicas, progresión del ciclo celular, migración y mutagenicidad. Resultados: los análisis in silico predijeron la actividad antitumoral a través de varios mecanismos de acción. Los resultados in vitro mostraron que la naringina presentó efectos citotóxicos, redujo el número de colonias, inhibió la migración celular y cambió la morfología y la progresión del ciclo celular de las dos líneas celulares evaluadas. Sin embargo, la naringina no presentó efectos mutagénicos. Conclusiones: la naringina tiene actividad antiproliferativa y es un candidato prometedor para el tratamiento del cáncer de vejiga.(AU)

Cancer cell metabolism connects epigenetic modifications to transcriptional regulation.

Adaptation of cellular function with the nutrient environment is essential for survival. Failure to adapt can lead to cell death and/or disease. Indeed, energy metabolism alterations are a major contributing factor for many pathologies, including cancer, cardiovascular disease, and diabetes. In particular, a primary characteristic of cancer cells is altered metabolism that promotes survival and proliferation even in the presence of limited nutrients. Interestingly, recent studies demonstrate that metabolic pathways produce intermediary metabolites that directly influence epigenetic modifications in the genome. Emerging evidence demonstrates that metabolic processes in cancer cells fuel malignant growth, in part, through epigenetic regulation of gene expression programs important for proliferation and adaptive survival. In this review, recent progress toward understanding the relationship of cancer cell metabolism, epigenetic modification, and transcriptional regulation will be discussed. Specifically, the need for adaptive cell metabolism and its modulation in cancer cells will be introduced. Current knowledge on the emerging field of metabolite production and epigenetic modification will also be reviewed. Alterations of DNA (de)methylation, histone modifications, such as (de)methylation and (de)acylation, as well as chromatin remodeling, will be discussed in the context of cancer cell metabolism. Finally, how these epigenetic alterations contribute to cancer cell phenotypes will be summarized. Collectively, these studies reveal that both metabolic and epigenetic pathways in cancer cells are closely linked, representing multiple opportunities to therapeutically target the unique features of malignant growth.

SELECTION AND TESTING OF EXPERIMENTAL MODELS OF NORMAL AND MALIGNANT HUMAN CELLS IN VITRO AND EVALUATION OF THEIR SENSITIVITY RANGE TO THE NEUTRON/CAPTURE AND PHOTON/CAPTURE AGENTS AND PHOTOSENSITIZERS. / VIDBIR TA APROBUVANNIa EKSPERYMENTAL'NYKh MODELEI NORMAL'NYKh TA ZLOIaKISNYKh KLITYN LIuDYNY IN VITRO TA DOSLIDZhENIa MEZh ÏKhN'OÏ ChUTLYVOSTI DLIa NEITRONOZAKhVATNYKh, FOTON/ZAKhVATNYKh AGENTIV TA FOTOSENSYBILIZATORIV.

OBJECTIVE: to investigate the structural and morpho-functional changes in test systems of malignant (A-549 cellline) and normal (fibroblasts of the 6th passage) human cells during incubation with gadolinium-containing pho-ton-capture agent «Dotavist¼ and photosensitizer «Fotolon¼. METHODS: The passaged (continuously interweaved) cell culture technique on normal human fibroblasts and malig-nant human cells; cytological, biophysical, statistical methods. RESULTS: The cytotoxic properties of «Dotavist¼ gadolinium-containing photon-capturing agent and «Photolon¼photosensitizer in a wide range of concentrations (5, 10, 25, 50, 100 and 200 µl/ml) were studied by the morpho-functional characteristics (growth kinetics, proliferative and mitotic activity, presence of atypical cells) in the invitro test systems of malignant (non-small cell lung cancer cell line A-549) and normal (6th passage fibroblasts)human cells. It was found that the cytotoxic properties of «Dotavist¼ in test systems of malignant and normal cellsare expressed under its administration in high concentrations (100 and 200 µl/ml). During incubation with«Photolon¼ photosensitizer the cytotoxic effect on malignant cells was determined at the lowest concentrations (5and 10 µl/ml). Photosensitizer administration in the increasing concentrations has lead to genotoxic effects.Cytotoxic effect of photosensitizer on the normal human fibroblasts was evident in the 5-200 µl/ml concentrationrange. There was a moderate decrease in mitotic activity along with increasing concentration. Genotoxic propertiesof photosensitizer were evident at 25 µl/ml concentration and above. CONCLUSION: Study results of the effectiveness of neutron-capture and photon-capture technologies by the sensi-tivity assay in the in vitro test systems of human malignant cells (non-small cell lung cancer cell line A-549) andnormal cells (transplantable human fibroblast culture, the 6th passage) to the gadolinium-containing photon-cap-ture «Dotavist¼ agent and «Photolon¼ photosensitizer in different concentrations provide the basis for pre-clinicalstage of evaluating the effectiveness of medications used in binary technologies.

Identification of key genes in osteosarcoma - before and after CDK7 treatment.

BACKGROUND: Osteosarcoma is one of the most common bone tumors, with a high degree of malignancy and a poor prognosis. Recent studies have shown that THZ2, a cyclin-dependent kinase 7 inhibitor, can exhibit strong antibone tumor effects in vivo and in vitro by inhibiting transcriptional activity. In this study, by screening the differentially expressed genes (DEGs) of osteosarcoma cells before and after THZ2 treatment, it provides new possible targets for the future targeted therapy of osteosarcoma. METHODS: Download the gene expression profile of GSE134603 from the Gene Expression Omnibus database, and use the R software package "limma Geoquery" to screen DEGs. DAVID database was used for gene ontology analysis of DEGs. Use search tool for the retrieval of interacting genes online database and Cytoscape software to construct protein-protein interaction network. Use the "MCODE" plugin in Cytoscape to analyze key molecular complexes (module) of DEGs, and use the "Cluego" plugin to perform Kyoto Encyclopedia of Genes and Genomes enrichment analysis on module genes. The Hub gene is selected from the genes in DEGs that coexist in the top 30 Degree and the Kyoto Encyclopedia of Genes and Genomes pathway. RESULTS: A total of 1033 DEGs were screened, including 800 up-regulated genes and 233 down-regulated genes. Gene ontology analysis showed that cell component is the main enrichment area of DEGs, mainly in the nucleus, cytoplasm, and nucleoplasm. In addition, in molecular function analysis, DEGs are mainly enriched in the process of protein binding. In biological process analysis, changes in DEGs can also be observed in transcription and regulation using DNA as a template. Twenty-nine module genes are enriched in the Ribosome biogenesis in eukaryotes pathway. Finally, 4 key genes are drawn: essential for mitotic growth 1, U3 SnoRNP protein 3 homolog, U3 small nucleolar RNA-associated protein 15 homolog, and WD repeat domain 3. CONCLUSION: This study found that the 4 genes essential for mitotic growth 1, U3 SnoRNP protein 3 homolog, U3 small nucleolar RNA-associated protein 15 homolog, WD repeat domain 3, and the ribosome biogenesis in eukaryotes pathway play a very important role in the occurrence and development of osteosarcoma, and can become a new target for molecular targeted therapy of osteosarcoma in the future.

Human-Relevant Sensitivity of iPSC-Derived Human Motor Neurons to BoNT/A1 and B1.

The application of botulinum neurotoxins (BoNTs) for medical treatments necessitates a potency quantification of these lethal bacterial toxins, resulting in the use of a large number of test animals. Available alternative methods are limited in their relevance, as they are based on rodent cells or neuroblastoma cell lines or applicable for single toxin serotypes only. Here, human motor neurons (MNs), which are the physiological target of BoNTs, were generated from induced pluripotent stem cells (iPSCs) and compared to the neuroblastoma cell line SiMa, which is often used in cell-based assays for BoNT potency determination. In comparison with the mouse bioassay, human MNs exhibit a superior sensitivity to the BoNT serotypes A1 and B1 at levels that are reflective of human sensitivity. SiMa cells were able to detect BoNT/A1, but with much lower sensitivity than human MNs and appear unsuitable to detect any BoNT/B1 activity. The MNs used for these experiments were generated according to three differentiation protocols, which resulted in distinct sensitivity levels. Molecular parameters such as receptor protein concentration and electrical activity of the MNs were analyzed, but are not predictive for BoNT sensitivity. These results show that human MNs from several sources should be considered in BoNT testing and that human MNs are a physiologically relevant model, which could be used to optimize current BoNT potency testing.

Establishment of patient-derived organotypic tumor spheroid models for tumor microenvironment modeling.

Patient-derived cancer models that reconstitute the characteristics of the tumor microenvironment may facilitate efforts in precision immune-oncology and the discovery of effective anticancer therapies. Organoids that have recently emerged as robust preclinical models typically contain tumor epithelial cells and lack the native tumor immune microenvironment. A patient-derived organotypic tumor spheroid (PDOTS) is a novel and innovative ex vivo system that retains key features of the native tumor immune microenvironment. Here, we established and characterized a series of colorectal cancer PDOTS models for use as a preclinical platform for testing effective immunotherapy and its combinations with other drugs. Partially dissociated (> 100 µm in diameter) tumor tissues were embedded in Matrigel-containing organoid media and subsequently formed into organoid structures within 3 to 7 days of culture. The success rate of growing PDOTS from fresh tissues was ~86%. Morphological analysis showed that the PDOTSs varied in size and structure. Immunofluorescence and flow cytometry analysis revealed that the PDOTSs retained autologous tumor-infiltrating lymphoid cells and tumor-infiltrating lymphoid cells were continually decreased through serial passages. Notably, PDOTSs from tumors from a high-level microsatellite instability-harboring patient were sensitive to anti-PD-1 or anti-PD-L1 antibodies. Our results demonstrate that the PDOTS model in which the tumor immune microenvironment is preserved may represent an advantageous ex vivo system to develop effective immune therapeutics.

Anti-Glioma Effect of Pseudosynanceia melanostigma Venom on Isolated Mitochondria from Glioblastoma Cells

Background: Glioblastoma is the most common primary malignant tumor of the central nervous system that occurs in the spinal cord or brain. Pseudosynanceia melanostigma is a venomous stonefish in the Persian Gulf, which our knowledge about is little. This study's goal is to investigate the toxicity of stonefish crude venom on mitochondria isolated from U87 cells. Methods: In the first stage, we extracted venom stonefish and then isolated mitochondria have exposed to different concentrations of venom. Finally, mitochondrial toxicity parameters (Succinate dehydrogenase (SDH) activity, Reactive oxygen species (ROS), cytochrome c release, Mitochondrial Membrane Potential (MMP), and mitochondrial swelling) have evaluated. Results: To determine mitochondrial parameters, we used 115, 230, and 460 µg/ml concentrations. The results of our study show that the venom of stonefish selectively increases upstream parameters of apoptosis such as mitochondrial swelling, cytochrome c release, MMP collapse and ROS. Conclusion: This study suggests that Pseudosynanceia melanostigma crude venom has selectively caused toxicity by increasing active mitochondrial oxygen radicals. This venom could potentially be a candidate for the treatment of glioblastoma.

Hydroxyethyl chitosan hydrogels for enhancing breast cancer cell tumorigenesis.

Polysaccharide hydrogels are promising candidate matrices for recapitulating the characteristics of extracellular matrix (ECM) in breast tumors in terms of their structure and composition. Herein, to obtain an ECM-mimetic matrix, hydroxyethyl chitosan (HECS) hydrogels were prepared through Schiff-base crosslinking reaction using dialdehyde hyaluronic acid as crosslinker. The obtained HECS hydrogels displayed a highly porous structure, a stiffness comparable to that of breast tissue, and a fast water-absorption speed. The amount of crosslinker had great effects on the swelling and rheological behaviors of the HECS hydrogels. Preliminary results from in vitro biological assessments confirmed that MCF-7 cells incubated within HECS hydrogels preferred to grow into three-dimensional spheroids. Importantly, the cells displayed enhanced migrative capability and upregulated expression levels of MMP-2, TGF-ß and VEGF in comparison to two-dimension cultured cells. Hence, the HECS hydrogels show great promise as a biomimetic ECM in constructing breast tumor models.

Meet me halfway: Are in vitro 3D cancer models on the way to replace in vivo models for nanomedicine development?

The complexity and diversity of the biochemical processes that occur during tumorigenesis and metastasis are frequently over-simplified in the traditional in vitro cell cultures. Two-dimensional cultures limit researchers' experimental observations and frequently give rise to misleading and contradictory results. Therefore, in order to overcome the limitations of in vitro studies and bridge the translational gap to in vivo applications, 3D models of cancer were developed in the last decades. The three dimensions of the tumor, including its cellular and extracellular microenvironment, are recreated by combining co-cultures of cancer and stromal cells in 3D hydrogel-based growth factors-inclusive scaffolds. More complex 3D cultures, containing functional blood vasculature, can integrate in the system external stimuli (e.g. oxygen and nutrient deprivation, cytokines, growth factors) along with drugs, or other therapeutic compounds. In this scenario, cell signaling pathways, metastatic cascade steps, cell differentiation and self-renewal, tumor-microenvironment interactions, and precision and personalized medicine, are among the wide range of biological applications that can be studied. Here, we discuss a broad variety of strategies exploited by scientists to create in vitro 3D cancer models that resemble as much as possible the biology and patho-physiology of in vivo tumors and predict faithfully the treatment outcome.

Drug responsiveness of leukemic cells detected in vitro at diagnosis correlates with therapy response and survival in patients with acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is the most common acute leukemia in adults, and chemotherapy remains the most commonly used treatment approach for this group of hematological disorders. Drug resistance is one of the predictors of unfavorable prognosis for leukemia patients. AIM: The purpose of this study was to perform a retrospective analysis of the survival rate in AML patients according to age, tumor status, and chemotherapy regimen received and to analyze the therapy response of AML patients depending on the treatment received, initial responsiveness of tumor cells to chemotherapeutic drugs measured in vitro at diagnosis and expression of immunological markers. METHODS: The survival of AML patients (n = 127) was analyzed using the Kaplan-Meier method. Drug sensitivity of tumor cells of AML patients (n = 37) and the expression of immunological markers were evaluated by the WST test and flow cytometry, respectively. Correlation analysis was performed using Spearman's rank order correlation coefficient. RESULTS: We found the treatment regimen to be the defining factor in the patient survival rate. In addition, the initial responsiveness of tumor cells to chemotherapeutic drugs measured in vitro at diagnosis correlated with the therapy response of AML: patients with high tumor cell sensitivity to particular cytotoxic drugs demonstrated a good response to treatment including these drugs, and patients with initial resistance of tumor cells to a particular chemotherapeutic agents and received it according to the clinical protocols demonstrated a poor response to antitumor therapy. Correlations of drug resistance in leukemic cells with the expression of immature and aberrant immunophenotype markers as established unfavorable prognostic factors confirm our assumption. CONCLUSION: The evaluation of the responsiveness of tumor cells to chemotherapy in vitro at diagnosis can be a useful tool for predicting the response of leukemia patients to planned chemotherapy.

9-Arylimino noscapinoids as potent tubulin binding anticancer agent: chemical synthesis and cellular evaluation against breast tumour cells.

A library of 9-arylimino derivatives of noscapine was developed by coupling of Schiff base containing imine groups. Virtual screening using molecular docking with tubulin revealed three molecules, 12-14 that bind with high affinity. An improved predicted free energy of binding (FEB) of -5.390, -6.506 and -6.679 kcal/mol for the molecules 12-14 was found compared to noscapine (-5.135 kcal/mol). Furthermore, molecular dynamics simulation in combination with Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) revealed robust binding free energy of -166.03, -169.75 and -170.63 kcal/mol for the molecules 12, 13 and 14, respectively. These derivatives were strategically synthesized and experimentally validated for their anticancer activity. Tubulin binding assay revealed substantial binding of molecules 12-14 with purified tubulin. Further, their anticancer activity was demonstrated using two cancer cell lines (MCF-7 and MDAMB-231) and a panel of primary breast tumour cells. All these derivatives inhibited cellular proliferation in all the cancer cells that ranged between 30.1 and 5.8 µM, which is 1.7 to 7.52 fold lower than that of noscapine. Further, these novel derivatives arrest cell cycle in the G2/M-phase followed by induction of apoptosis. Thus, 9-arylimino noscapinoids 12-14 have a great potential to be a novel therapeutic agent for breast cancers.

ILF3-AS1 promotes cell proliferation and inhibits cell apoptosis of breast cancer by binding with miR-4429 to upregulate RAB14.

As one of the leading causes of cancer-related deaths among women, breast cancer accounts for a 30% increase of incidence worldwide since 1970s. Recently, increasing studies have revealed that the long non-coding RNA ILF3-AS1 is involved in the progression of various cancers. Nevertheless, the role of ILF3-AS1 in breast cancer remains largely unknown. In the present study, we found that ILF3-AS1 was highly expressed in breast cancer tissues and cells. ILF3-AS1 silencing inhibited breast cancer cell proliferation, migration and invasion, and promoted cell apoptosis. ILF3-AS1 bound with miR-4429 in breast cancer cells. Moreover, RAB14 was a downstream target of miR-4429, and miR-4429 expression was negatively correlated with RAB14 or ILF3-AS1 expression in breast cancer tissues. The result of rescue experiments demonstrated that overexpression of RAB14 can reverse the inhibitory effect of ILF3-AS1 knockdown on breast cancer cell proliferation, migration and invasion. Overall, ILF3-AS1 promotes the malignant phenotypes of breast cancer cells by interacting with miR-4429 to regulate RAB14, which might offer a new insight into the underlying mechanism of breast cancer.

Effect of fenofibrate on proliferation of SMMC-7721 cells via regulating cell cycle.

Liver cancer is a malignant cancer with great harmfulness. Fenofibrate is a peroxisome proliferation activated receptor (PPARα) agonist widely used in the treatment of dyslipidemia. Previous studies have shown that fenofibrate may promote cell proliferation, but the underlying mechanism has not been fully characterized. The aim of this study was to investigate the role of PPARα agonist fenofibrate in cell proliferation of SMMC-7721 cells compared with that of THLE-2 cells. SMMC-7721 and THLE-2 cells were treated with different concentrations of fenofibrate. Cell proliferation was analyzed by MTT, using flow cytometry for cell cycle analysis, and CyclinD1, Cyclin-dependent kinases2 (CDK2) and Proliferating Cell Nuclear Antigen (PCNA) were analyzed by Western blotting. RT-qPCR method was used to assess CDK2, CyclinD1 and PCNA mRNA levels. The results showed that 10-9-10-4 mol/L fenofibrate could induce cell growth and 10-4, 10-5, 10-6 mol/L fenofibrate could reduce the number of G0/G1 phase cells and increased in the number of cells in S and G2/M phase of cell cycle in SMMC-7721 cells. Furthermore, fenofibrate could significantly increase the expression of cell cycle related protein (CyclinD1, CDK2)and cell proliferation related proteins (PCNA). The use of PPARα inhibitor MT886 inhibited cell cycle progression and promote tumor cell apoptosis. But fenofibrate had no obvious effect on THLE-2 cells. These results revealed the effect of fenofibrate on the cell cycle of liver cancer cells, and provided a reasonable explanation for studying how fenofibrate promotes cell proliferation.

α-Melanocyte-Stimulating Hormone Triggers Melanogenesis Via Activation of the Aryl Hydrocarbon Receptor Pathway in B16F10 Mouse Melanoma Cells.

Melanin is a group of natural pigments that determines the human skin color and provides fundamental protection against the harmful impacts of physical and chemical stimuli. The aim of this study was to establish the regulatory role of aryl hydrocarbon receptor (AhR) in α-melanocyte-stimulating hormone (α-MSH) induced melanogenesis. In the present study, following knockdown of AhR, murine B16F10 cells were treated with α-MSH (200 nM) and tyrosinase activities, cellular melanin content, mRNA levels of several important genes involved in melanogenesis including AhR, CTNNB1, TYR2, and microphthalmia-associated transcription factor (MITF) were measured as endpoints. Exposure to α-MSH led to elevated expression of AhR, CTNNB1, MITF, and TYR in accordance with increased tyrosinase enzyme activity as well as a significant rise in the total melanin content. Our results suggest that AhR plays a regulatory role in α-MSH-stimulated melanogenesis.

A new look at 9-substituted acridines with various biological activities.

Heterocycles have long been the focus of intensive study in attempts to develop novel therapeutic compounds, and acridine, a polynuclear nitrogen molecule containing a heterocycle, has attracted a considerable amount of scientific attention. Acridine derivatives have been studied in detail and have been found to possess multitarget properties, which inhibit topoisomerase enzymes that regulate topological changes in DNA and interfere with the essential biological function of DNA. This article describes some recent advancements in the field of new 9-substituted acridine heterocyclic agents and describes both the structure and the structure-activity relationship of the most promising molecules. The article will also present the IC50 values of the novel derivatives against various human cancer cell lines. The mini review also investigates the topoisomerase inhibition and antibacterial and antimalarial activity of these polycyclic aromatic derivatives.

Pharmacologic Screening Identifies Metabolic Vulnerabilities of CD8+ T Cells.

Metabolic constraints in the tumor microenvironment constitute a barrier to effective antitumor immunity and similarities in the metabolic properties of T cells and cancer cells impede the specific therapeutic targeting of metabolism in either population. To identify distinct metabolic vulnerabilities of CD8+ T cells and cancer cells, we developed a high-throughput in vitro pharmacologic screening platform and used it to measure the cell type-specific sensitivities of activated CD8+ T cells and B16 melanoma cells to a wide array of metabolic perturbations during antigen-specific killing of cancer cells by CD8+ T cells. We illustrated the applicability of this screening platform by showing that CD8+ T cells were more sensitive to ferroptosis induction by inhibitors of glutathione peroxidase 4 (GPX4) than B16 and MC38 cancer cells. Overexpression of ferroptosis suppressor protein 1 (FSP1) or cytosolic GPX4 yielded ferroptosis-resistant CD8+ T cells without compromising their function, while genetic deletion of the ferroptosis sensitivity-promoting enzyme acyl-CoA synthetase long-chain family member 4 (ACSL4) protected CD8+ T cells from ferroptosis but impaired antitumor CD8+ T-cell responses. Our screen also revealed high T cell-specific vulnerabilities for compounds targeting NAD+ metabolism or autophagy and endoplasmic reticulum (ER) stress pathways. We focused the current screening effort on metabolic agents. However, this in vitro screening platform may also be valuable for rapid testing of other types of compounds to identify regulators of antitumor CD8+ T-cell function and potential therapeutic targets.

Involvement of a novel regulatory cascade consisting of SET-H3K18ac/H3K27ac-53BP1 in Cr(VI)-induced malignant transformation of 16HBE cells.

Hexavalent chromium (Cr(VI)) is a well-established human carcinogen with DNA damaging effects. Recently we established a Cr(VI)-induced malignant transformation model from a human bronchial epithelial (16HBE) cell line, and in the transformed (16HBE-T) cells reduced levels of 53BP1 (critical for DNA repair) and the acetylated histone H3K18/27 (H3K18/27ac) were observed. In 16HBE-T cells SET (a multifunctional protein) was elevated by Cr(VI) through quantitative proteomics analysis. In the present study, we further explore the involvement of SET in the H3K18/27ac/53BP1 cascade in the 16HBE-T model, primarily by knockdown of SET. Bioinformatic analysis of the differentially expressed proteins indicated enrichment in histone modifications, in which SET was a major regulator. In 16HBE cells SET expression was enhanced by Cr(VI) in a concentration- and exposure duration-dependent manner. In 16HBE-T cells, SET knockdown showed the following effects: reversal of H3K18/27ac and 53BP1 levels, enhanced enrichment H3K18/27ac in 53BP1's promotor region, increase rate of apoptosis and cell cycle G0/G1 arrest (with or without Cr(VI) treatment), and reduced colony-forming efficiency. Finally, In comparison with benzo(a)pyrene-transformed (malignant, 16HBE-B) cells from 16HBE where no changes in H3K18/27ac, 53BP1 or SET were observed, while the H3K18/27ac/53BP1 cascade was downregulated and SET upregulated in 16HBE-T cells, as compared with the parental 16HBE cells; thus the changes in 16HBE-T might be a specific effect of Cr(VI). In conclusion, our results suggest that SET may be involved in the malignant cell transformation, through inhibiting the H3K18/27ac/53BP1 cascade, at least in the 16HBE cell model.

Phenotypic profiling with a living biobank of primary rhabdomyosarcoma unravels disease heterogeneity and AKT sensitivity.

Cancer therapy is currently shifting from broadly used cytotoxic drugs to patient-specific precision therapies. Druggable driver oncogenes, identified by molecular analyses, are present in only a subset of patients. Functional profiling of primary tumor cells could circumvent these limitations, but suitable platforms are unavailable for most cancer entities. Here, we describe an in vitro drug profiling platform for rhabdomyosarcoma (RMS), using a living biobank composed of twenty RMS patient-derived xenografts (PDX) for high-throughput drug testing. Optimized in vitro conditions preserve phenotypic and molecular characteristics of primary PDX cells and are compatible with propagation of cells directly isolated from patient tumors. Besides a heterogeneous spectrum of responses of largely patient-specific vulnerabilities, profiling with a large drug library reveals a strong sensitivity towards AKT inhibitors in a subgroup of RMS. Overall, our study highlights the feasibility of in vitro drug profiling of primary RMS for patient-specific treatment selection in a co-clinical setting.

The effects of size and shape of the ovarian cancer spheroids on the drug resistance and migration.

BACKGROUND: High fatality in ovarian cancer is attributed to metastasis, propagated by the release of multi-cellular aggregates/spheroids into the peritoneal cavity and their subsequent mesothelial invasion of peritoneal organs. Spheroids are therefore a common and clinically relevant in vitro model for ovarian cancer research. Spheroids in patients vary significantly in size and shape and display enhanced resistance to anti-cancer drugs compared to monolayers. However, there is no consensus on how spheroid size and shape affect drug resistance. Moreover, existing data regarding the influence of epithelial-to-mesenchymal transition (EMT) profile on spheroid shape and migration is inconclusive. METHODS: We formed spheroids with OVCAR-3 and OVCAR-8 cells, chosen for their established genetic similarity to the patient tumor samples. We monitored their morphology using confocal microscope with dipping objective and fluorescent microscope. We characterized important EMT biomarkers; E-cadherin, Vimentin and Slug through western blotting in monolayers and spheroids. We treated these spheroids with Taxol and Cisplatin and investigated their migratory profile based on their morphology. RESULTS: We report two distinct multicellular structures: loose aggregates (OVCAR-3) and compact spheroids (OVCAR-8). We attribute these different morphologies to the expression of the EMT biomarkers, and their changes upon spheroid formation. Importantly, we did not observe a difference in resistance to the anti-cancer drugs as a function of spheroid size and shape. However, migration capacity of compact spheroid (OVCAR-8) was 15-fold higher compared to that of loose aggregates (OVCAR-3). CONCLUSIONS: These results highlight the importance of spheroid size and shape on anti-cancer drug resistance and migration profiles. The results of this study can, therefore, help to elucidate general rules for ovarian cancer studies based on 3D samples.