Resistant Models Research Articles

An in vitro Model to Study Placental Functions in Gestational Diabetes Mellitus

Background: Gestational diabetes mellitus (GDM) is a serious pregnancy complication that affects around 14 % of pregnancies worldwide. It not only causes short-term complications in the mother and child but also significantly increases the risks of several chronic diseases, including cardiovascular diseases and diabetes. An excess production of the soluble vascular endothelial growth factor (VEGF) receptor 1 in the placenta, which is a natural inhibitor of VEGF, has been linked to various pregnancy complications. However, placentas affected by GDM often exhibit increased vascularization, suggesting that the role of VEGF in GDM differs from its impact on typical pregnancy complications. Unfortunately, limited studies on placental functions in GDM have been conducted due to a lack of reliable culture models. Methods: In this study, we developed an in vitro model of GDM using the human choriocarcinoma trophoblast cell line BeWo and examined the effects of VEGF on glucose uptake. The BeWo cells were treated with a high glucose-containing (25 mM) syncytialization differentiation medium to produce insulin-resistant cells. Insulin resistance was assessed by a glucose uptake assay using the fluorescent glucose analog 2-NBDG and flow cytometry analysis. Results: The cells treated with high glucose exhibited a significant decrease in glucose uptake, suggesting the successful development of glucose resistance in these cells. However, VEGF treatment did not show a significant impact on glucose uptake in high glucose-treated cells. Conclusions: It is important to note that glucose homeostasis is a complex process involving multiple cell types, and further studies are necessary to fully understand the functions of VEGF on GDM placentas. Nevertheless, the in vitro model we have developed and validated will be a valuable tool for studying placental pathophysiology in GDM and evaluating the effectiveness of potential therapeutic agents. HIGHLIGHTS BeWo cells are the choriocarcinoma cell line which were cultured in the in vitro condition BeWo cells were differentiated using forskolin and 8-Br Camp Insulin resistant model of BeWo cells were prepared by high glucose (25 mM) treatment The effect of VEGF on glucose homeostasis in GDM model of BeWo cells was observed GRAPHICAL ABSTRACT

Ultrasound targeted microbubble destruction using docetaxel and Rose Bengal loaded Microbubbles for targeted Chemo-Sonodynamic therapy treatment of prostate cancer

Docetaxel (DTX) chemotherapy is commonly used in the treatment of patients with advanced prostate cancer demonstrating modest improvements in survival. As these patients are often elderly and the chemotherapy treatment is not targeted, it is often poorly tolerated. More targeted approaches that increase therapeutic efficacy yet reduce the amount of toxic chemotherapy administered are needed. In this manuscript, we investigate the potential of ultrasound targeted microbubble destruction (UTMD) to deliver a combination of docetaxel chemotherapy and Rose Bengal mediated sonodynamic therapy (SDT) in pre-clinical prostate cancer models. A Rose Bengal modified phospholipid was synthesized and used as a component lipid to prepare a microbubble (MB) formulation that was also loaded with DTX. The DTX-MB-RB formulation was used in the UTMD mediated treatment of androgen sensitive and androgen resistant 3D spheroid and murine models of prostate cancer. Results from the 3D spheroid experiments showed UTMD mediated DTX-MB-RB chemo-sonodynamic therapy to be significantly more effective at reducing cell viability than UTMD mediated DTX or SDT treatment alone. In an androgen sensitive murine model of prostate cancer, UTMD mediated DTX-MB-RB chemo-sonodynamic therapy was as effective as androgen deprivation therapy (ADT) at controlling tumour growth. However, when both treatments were combined, a significant improvement in tumour growth delay was observed. In an androgen resistant murine model, UTMD mediated DTX-MB-RB chemo-sonodynamic therapy was significantly more effective than standard DTX monotherapy. Indeed, the DTX dose administered using the DTX-MB-RB formulation was 91% less than standard DTX monotherapy. As a result, UTMD mediated DTX-MB-RB treatment was well tolerated while animals treated with DTX monotherapy displayed significant weight loss which was attributed to acute toxic effects. These results highlight the potential of UTMD mediated DTX-MB-RB chemo-sonodynamic therapy as a targeted, well tolerated alternative treatment for advanced prostate cancer.

Resistance to PRMT5-targeted therapy in mantle cell lymphoma

AbstractMantle cell lymphoma (MCL) is an incurable B-cell non-Hodgkin lymphoma, and patients who relapse on targeted therapies have poor prognosis. Protein arginine methyltransferase 5 (PRMT5), an enzyme essential for B-cell transformation, drives multiple oncogenic pathways and is overexpressed in MCL. Despite the antitumor activity of PRMT5 inhibition (PRT-382/PRT-808), drug resistance was observed in a patient-derived xenograft (PDX) MCL model. Decreased survival of mice engrafted with these PRMT5 inhibitor–resistant cells vs treatment-naive cells was observed (P = .005). MCL cell lines showed variable sensitivity to PRMT5 inhibition. Using PRT-382, cell lines were classified as sensitive (n = 4; 50% inhibitory concentration [IC50], 20-140 nM) or primary resistant (n = 4; 340-1650 nM). Prolonged culture of sensitive MCL lines with drug escalation produced PRMT5 inhibitor–resistant cell lines (n = 4; 200-500 nM). This resistant phenotype persisted after prolonged culture in the absence of drug and was observed with PRT-808. In the resistant PDX and cell line models, symmetric dimethylarginine reduction was achieved at the original PRMT5 inhibitor IC50, suggesting activation of alternative resistance pathways. Bulk RNA sequencing of resistant cell lines and PDX relative to sensitive or short-term–treated cells, respectively, highlighted shared upregulation of multiple pathways including mechanistic target of rapamycin kinase [mTOR] signaling (P < 10-5 and z score > 0.3 or < 0.3). Single-cell RNA sequencing analysis demonstrated a strong shift in global gene expression, with upregulation of mTOR signaling in resistant PDX MCL samples. Targeted blockade of mTORC1 with temsirolimus overcame the PRMT5 inhibitor–resistant phenotype, displayed therapeutic synergy in resistant MCL cell lines, and improved survival of a resistant PDX.

The Effect of Interconnecting Ribbons in External Resistance of Crystalline Silicon Photovoltaic Modules

The interconnecting ribbons in commercial crystalline silicon (c-Si) photovoltaic (PV) modules significantly contribute to the external resistance of the modules. This external resistance plays a major role in resistive losses in the modules and thus measures should be taken in minimization of such resistances. A wider ribbon cause blockage for the incoming light in the solar cells. In addition, the selection of wrong ribbon configuration essentially leads to breakage in fingers which further enhances resistive losses in the modules. In this paper, an analytical approach using a resistive network model has been proposed which effectively describes the effect of ribbon dimension on the blockage area as well as external resistance of the modules. The model has been useful to understand the resistive effect in the PV modules in a quantitative manner. The results show that the number of busbars and the width of the busbars in a solar cell play a significant role in choosing the right ribbon configuration. The proposed approach is useful to understand the optimum ribbon configuration in newly manufactured c-Si PV modules.

Combination Immunotherapy with Partial Versus Whole Tumor Radiotherapy in a Preclinical Melanoma Tumor Model

Partial tumor radiotherapy (PTRT) with immune checkpoint inhibition (ICI) is currently the subject of clinical trials and may be used clinically for large volume tumors when the full gross tumor volume (GTV) cannot be safely treated with full dose. PTRT delivers RT to a portion of the GTV, underdosing or not treating the remainder of the GTV, hypothesizing that ICI-mediated tumor infiltrating lymphocyte (TIL) infiltration will produce adequate disease control in un- or under-irradiated GTV. Standard treatment is whole tumor radiotherapy (WTRT), and potential differences in disease control between PTRT and WTRT with ICI have not been robustly assessed. We hypothesized that PTRT with ICI and WTRT with ICI will demonstrate similar tumor regression, and both RT regimens will demonstrate superior tumor regression as compared to ICI alone. B78 melanoma flank tumors were generated in C57B/L6 mice, with randomization at tumor size of 1 cm to experimental cohorts of PTRT + ICI and WTRT + ICI and control groups of no RT ± ICI. Custom lead shields were fabricated to deliver 16 Gy single fraction PTRT (50% tumor treatment) and WTRT, with dosimetry confirmation via radiochromic film. ICI was delivered through I.P. injection of murine anti-CTLA4 and anti-PD-L1 at days 0, 3, and 6 post-RT. Tumor regression was assessed via differences in tumor volume at ten days post completion of ICI, and mean cohort tumor volumes were compared with ANOVA (α <0.05). Variances between individual cohorts were assessed via t-test (α <0.05). Treatment cohorts demonstrated significant variance in tumor volume at ten days following treatment completion (p = 0.007, Table 1). WTRT + ICI demonstrated superior tumor regression when compared to PTRT + ICI (p = 0.006), ICI alone (p = 0.002), and control cohorts (p = 0.013). There was no difference in tumor regression between PTRT + ICI and ICI alone (p = 0.709), and PTRT + ICI did not achieve significant regression when compared to control (p = 0.083). Tumor regression did not differ between cohorts receiving no RT ± ICI (p = 0.103). Our results in this ICI resistant melanoma model demonstrated superior tumor regression with WTRT + ICI as compared to PTRT + ICI and ICI alone, suggesting that even with concurrent ICI, PTRT may not be sufficient treatment for melanoma. PTRT + ICI tumor regression was similar to ICI alone, suggesting that PTRT may not overcome immune resistance in the unirradiated tumor volume. Further investigation of optimal RT regimens to potentiate ICI response is warranted and correlative studies examining spatial immunomodulation in unirradiated and irradiated portions of the same tumor are underway.

Pevonedistat, a first-in-class NEDD8-activating enzyme inhibitor, sensitizes cancer cells to VSVΔ51 oncolytic virotherapy

The clinical efficacy of VSVΔ51 oncolytic virotherapy has been limited by tumor resistance to viral infection, so strategies to transiently repress antiviral defenses are warranted. Pevonedistat is a first-in-class NEDD8-activating enzyme (NAE) inhibitor currently being tested in clinical trials for its antitumor potential. In this study, we demonstrate that pevonedistat sensitizes human and murine cancer cells to increase oncolytic VSVΔ51 infection, increase tumor cell death, and improve therapeutic outcomes in resistant syngeneic murine cancer models. Increased VSVΔ51 infectivity was also observed in clinical human tumor samples. We further identify the mechanism of this effect to operate via blockade of the type 1 interferon (IFN-1) response through neddylation-dependent interferon-stimulated growth factor 3 (ISGF3) repression and neddylation-independent inhibition of NF-κB nuclear translocation. Together, our results identify a role for neddylation in regulating the innate immune response and demonstrate that pevonedistat can improve the therapeutic outcomes of strategies using oncolytic virotherapy.

Kisspeptin-mediated improvement of sensitivity to BRAF inhibitors in vemurafenib-resistant melanoma cells.

Metastatic dissemination is still one of the major causes of death of melanoma's patients. KiSS1 is a metastasis suppressor originally identified in melanoma cells, known to play an important physiological role in mammals' development and puberty. It has been previously shown that expression of KiSS1 could be increased in lung cancer cells using epigenetic agents, and that KiSS1 could have a pro-apoptotic action in combination with cisplatin. Thus, the aim of the present study was to examine in human melanoma vemurafenib sensitive- and -resistant BRAF mutant cells characterized by different mutational profiles and KiSS1, KiSS1 receptor and KiSS1 drug-induced release, if peptides derived from KiSS1 cleavage, i.e., kisspeptin 54, could increase the sensitivity to vemurafenib of human melanoma, using cellular, molecular and biochemical approaches. We found that kisspeptin 54 increases vemurafenib pro-apoptotic activity in a statistically significant manner, also in drug resistant cellular models. The efficacy of the combination appears to reflect the intrinsic susceptibility of each cell line to PLX4032-induced apoptosis, together with the different mutational profile as well as perturbation of proteins regulating the apoptotic pathway, The results presented here highlight the possibility to exploit KiSS1 to modulate the apoptotic response to therapeutically relevant agents, suggesting a multitasking function of this metastasis suppressor.

Abstract PO-093: Crenolanib improves PD-1 response and overall survival in immune checkpoint inhibitor resistant murine models of oral squamous cell carcinoma

Abstract Background: Present line indications for pembrolizumab are for patients with metastatic or unresectable recurrent (i.e. incurable) head and neck squamous cell carcinoma (HNSCC). However, only a minority of patients on immunotherapy will realize a durable survival benefit because &amp;gt;80% of patients with metastatic HNSCC do not respond to PD-1 blockade. Tumor microenvironment mesenchymal stem cells (MSCs) and cancer associated fibroblasts (CAFs) have been reported significantly contribute to chemotherapy and radiation resistance. Moreover, MSCs have been shown to contribute to an immunosuppressive tumor microenvironment by upregulating PD-L1 in breast cancer models. We have previously shown crenolanib improves MSC mediated cisplatin resistance in vitro through modulation of MSC-mediated activation of AKT signaling, therefore we hypothesize that targeting MSCs may be of therapeutic benefit alone and in combination with anti-PD1 immunotherapy. Methods: Oral cancer was induced in the buccal space of C56/BL6 mice with the murine oral cancer cell lines MOC1 or PD-1 resistant cell line, MOC2. When tumors reached approximately 5 × 5 mm, mice were treated with 15 mg/kg (low dose) or 30 mg/kg crenolanib (high dose) for five consecutive days over 3 weeks. Tissue were harvested for immunohistochemistry and immunofluorescence analysis and ex vivo cell cultures prepared for analysis by western immunoblotting and flow cytometry. Results: There was a significant reduction in tumor volume in mice bearing MOC1 and MOC2 tumors (p&amp;lt;0.03) treated with either low or high dose crenolanib compared to vehicle control. Overall survival was also significantly improved in mice bearing MOC1 tumors treated with high dose crenolanib compared to mice treated with vehicle control (p&amp;lt;0.04) and approached significance in MOC2 mice treated with low dose crenolanib. Tumor sections were imaged by immunofluorescence microscopy. There was a decrease in expression of PDGFR-α on MOC1 tumor cells and α-SMA on tumor microenvironment stromal cells in mice treated with crenolanib compared to vehicle control, suggesting crenolanib targets both cell types. There was a significant reduction in tumor volume (p&amp;lt;0.0001) and improved overall survival (p&amp;lt;0.0004) in mice bearing MOC2 tumors treated with combination crenolanib plus pembrolizumab compared to vehicle plus pembrolizumab. Conclusions: Preliminary in vivo data suggests crenolanib may be efficacious when used in combination with anti-PD1 immunotherapy by inhibiting the immunosuppressive effects of tumor microenvironment MSCs. Citation Format: Xiangfeng Shen, Katherine Gonzalez, Rico Castillo, Ashlyn Rickard, Yvonne Mowery, Tammara Watts. Crenolanib improves PD-1 response and overall survival in immune checkpoint inhibitor resistant murine models of oral squamous cell carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Innovating through Basic, Clinical, and Translational Research; 2023 Jul 7-8; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2023;29(18_Suppl):Abstract nr PO-093.

Abstract PO-078: Tissue-resident memory CD8+ T cells correlate with anti-PD-1 response in head and neck cancer and expand upon cDC1 activation in tumor-draining lymph nodes to overcome PD-1 resistance

Abstract Introduction: Tumor infiltrating tissue-resident memory CD8+ T (TRM) cells correlate with immunotherapy response against several solid tumor types. Recent data from neoadjuvant immunotherapy studies highlight CD8+ TRM cells as early responders in head and neck squamous carcinoma (HNSCC). Here, we defined anti-tumor CD8+ TRM cell representation in neoadjuvant anti-PD1 clinical trial HNSCC tumors and examined their development in anti-PD1 responsive and resistant HNSCC mouse models. Methods: CD8+ CD103+ TRM cells were quantified using CODEX (CO-detection by inDEXing) in tumor tissue microarray cores from 28 HNSCC patients treated with neoadjuvant anti-PD1 on a previously reported clinical trial (NCT02296684). Anti-PD1 sensitive MOC1 and isogenic anti-PD1 resistant MOC1-esc1 cells were engineered to express ovalbumin derived SIINFEKL peptide (OVA). OVA-specific CD8+ TRM induction and activation from endogenous T cells and following OT-1 adoptive transfer was evaluated in orthotopic (buccal) MOC1/MOC1esc1-OVA tumor bearing mice by ELISA and flow cytometry employing SIINFEKL-H2Kbdextramers. In vitro OVA-directed T cell activity was evaluated using co-culture of OT-1 T cells and MOC1/MOC1OVA/MOC1esc1OVA cells, OVA peptide, or IL-2. OT-1 CD8+ T cells were transferred into MOC1OVA or MOC1-esc1OVA-bearing mice and the dynamics of TRM development were evaluated using flow cytometry. Conventional Dendritic cells 1 (cDC1s) from tumor-draining lymph nodes (TDLNs) were cocultured with OT-1 cells and evaluated for antigen-specific TRM development. Results: CD8+ CD103+ TRM cells were more frequent in baseline tumors that developed pathological tumor response following neoadjuvant pembrolizumab compared to baseline nonresponding tumors (p=0.011). In mouse orthotopic models, MOC1-esc1OVA cells maintained in vivo PD-1 resistance despite eliciting SIINFEKL dextramer+ antigen-specific T cells in the tumors that expanded in response to PD-1 blockade. Further characterization of these tumor antigen specific T cells showed that compared to MOC1OVA, MOC1-esc1OVA had reduced CD69 and CD103 expression (MOC1OVA, Average 17.55% (14.1-19.4%); MOC1-esc1OVA, Average 11.84% (9.42-15.8%); p=0.025) and reduced response to SIINFEKL restimulation (MOC1OVA, Average 1093.3 pg/mL (860.6-1240.9 pg/mL); MOC1-esc1OVA, Average 533.3 pg/mL (254.5-749.0 pg/mL); p=0.006). A time course analysis in vivo showed that OVA-specific TRM cells were generated in TDLN and migrated into tumor. Compared to MOC1-OVA, MOC1-esc1OVA TDLN cDC1s had reduced CD40 expression and fewer TRM cells. Anti-CD40 blocking monoclonal antibodies reduced OVA-specific TRM cells in MOC1OVA while CD40 agonist antibodies increased antitumor TRMs and reduced PD1-resistant tumor growth compared to the control IgG groups. Conclusion: These findings highlight TRM CD8_+ T cells as a correlate of PD-1 blockade response in HNSCC patient tissues and mouse models and delineate cDC1 CD40 function in the TDLN as critical for effective antitumor TRM development. Citation Format: Michihisa Kono, Shin Saito, Geoff Ivison, Ayano Kondo, Aaron Mayer, Jonathan D. Schoenfeld, Ann Marie Egloff, Ravindra Uppaluri. Tissue-resident memory CD8+ T cells correlate with anti-PD-1 response in head and neck cancer and expand upon cDC1 activation in tumor-draining lymph nodes to overcome PD-1 resistance [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Innovating through Basic, Clinical, and Translational Research; 2023 Jul 7-8; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2023;29(18_Suppl):Abstract nr PO-078.

Theranostic imaging and multimodal photodynamic therapy and immunotherapy using the mTOR signaling pathway

Tumor metastases are considered the leading cause of cancer-associated deaths. While clinically applied drugs have demonstrated to efficiently remove the primary tumor, metastases remain poorly accessible. To overcome this limitation, herein, the development of a theranostic nanomaterial by incorporating a chromophore for imaging and a photosensitizer for treatment of metastatic tumor sites is presented. The mechanism of action reveals that the nanoparticles are able to intervene by local generation of cellular damage through photodynamic therapy as well as by systemic induction of an immune response by immunotherapy upon inhibition of the mTOR signaling pathway which is of crucial importance for tumor onset, progression and metastatic spreading. The nanomaterial is able to strongly reduce the volume of the primary tumor as well as eradicates tumor metastases in a metastatic breast cancer and a multi-drug resistant patient-derived hepatocellular carcinoma models in female mice.

Study of fingolimod, nitric oxide inhibitor, and P-glycoprotein inhibitor in modulating the P-glycoprotein expression via an endothelin-sphingolipid pathway in an animal model of pharmacoresistant epilepsy.

The overexpression of P-glycoprotein (P-gp) contributes to drug resistance in patients with epilepsy, and the change of P-gp expression located at the blood-brain barrier alienates the anti-seizure effects of P-gp substrates. Thus, the present study explored the effect of fingolimod (FTY720) acting through an endothelin-sphingolipid pathway on P-gp-induced pentylenetetrazol (PTZ)-kindled phenobarbital (PB)-resistant rats. PTZ kindling (30 mg/kg; i.p.) and PB (40 mg/kg; orally) were used to develop an animal model of refractory epilepsy. The effect of Fingolimod on seizure score (Racine scale), plasma and brain levels of PB (high-performance liquid chromatography), and blood-brain barrier permeability (Evans blue dye) was determined. Further, Fingolimod's neuroprotective effect was determined by measuring the levels of various inflammatory cytokines, oxidative stress parameters, and neurotrophic factors in rat brain homogenate. The Fingolimod's effect on P-gp expression was estimated by reverse transcriptase-polymerase chain reaction and immunohistochemistry in rat brain. The H and E staining was done to determine the neuronal injury. Fingolimod significantly (P < 0.001) reduced the seizure score in a dose-dependent manner and alleviated the blood-brain barrier permeability. It decreased the P-gp expression, which further increased the brain PB concentration. Fingolimod significantly (P < 0.01) reduced oxidative stress as well as inflammation. Moreover, it attenuated the raised neuronal injury score in a resistant model of epilepsy. The modulation of the P-gp expression by Fingolimod improved drug delivery to the brain in an animal model of refractory epilepsy. Therefore, S1P signaling could serve as an additional therapeutic target to overcome refractoriness.

Wheelchair Rugby Sprint Force-Velocity Modeling Using Inertial Measurement Units and Sport Specific Parameters: A Proof of Concept.

Para-sports such as wheelchair rugby have seen increased use of inertial measurement units (IMU) to measure wheelchair mobility. The accessibility and accuracy of IMUs have enabled the quantification of many wheelchair metrics and the ability to further advance analyses such as force-velocity (FV) profiling. However, the FV modeling approach has not been refined to include wheelchair specific parameters. The purpose of this study was to compare wheelchair rugby sprint FV profiles, developed from a wheel-mounted IMU, using current mono-exponential modeling techniques against a dynamic resistive force model with wheelchair specific resistance coefficients. Eighteen athletes from a national wheelchair rugby program performed 2 × 45 m all-out sprints on an indoor hardwood court surface. Velocity modelling displayed high agreeability, with an average RMSE of 0.235 ± 0.07 m/s-1 and r2 of 0.946 ± 0.02. Further, the wheelchair specific resistive force model resulted in greater force and power outcomes, better aligning with previously collected measures. The present study highlights the proof of concept that a wheel-mounted IMU combined with wheelchair-specific FV modelling provided estimates of force and power that better account for the resistive forces encountered by wheelchair rugby athletes.

Viscous Effects on Nonlinear Double Tearing Mode and Plasmoid Formation in Adjacent Harris Sheets

In this paper, we study the effects of viscosity on the evolution of the double tearing mode (DTM) in a pair of adjacent Harris sheets based on the resistive MHD model in the NIMROD code. Similar to the tearing mode in the conventional single Harris sheet, a transition is observed in the generation of both normal and monster plasmoids at Prandtl number Pr=1. In the Pr&lt;1 regime of the DTM, normal plasmoids (small plasmoids) are generated along with monster plasmoid, whereas in the single tearing mode (STM) cases, such a generation is not observed. When Pr is above the critical value, the generation of monster plasmoid is halted. Correspondingly, in the Pr&lt;1 regime, a quadrupolar flow advects along the poloidal direction, but in the Pr&gt;1 regime this flow advection is inhibited.

The acquisition order of leukemic drug resistance mutations is directed by the selective fitness associated with each resistance mechanism

In Chronic Myeloid Leukemia, the transition from drug sensitive to drug resistant disease is poorly understood. Here, we used exploratory sequencing of gene transcripts to determine the mechanisms of drug resistance in a dasatinib resistant cell line model. Importantly, cell samples were collected sequentially during drug exposure and dose escalation, revealing several resistance mechanisms which fluctuated over time. BCR::ABL1 overexpression, BCR::ABL1 kinase domain mutation, and overexpression of the small molecule transporter ABCG2, were identified as dasatinib resistance mechanisms. The acquisition of mutations followed an order corresponding with the increase in selective fitness associated with each resistance mechanism. Additionally, it was demonstrated that ABCG2 overexpression confers partial ponatinib resistance. The results of this study have broad applicability and help direct effective therapeutic drug usage and dosing regimens and may be useful for clinicians to select the most efficacious therapy at the most beneficial time.

An oncolytic virus-delivered TGFβ inhibitor overcomes the immunosuppressive tumor microenvironment.

While checkpoint blockade immunotherapies have widespread success, they rely on a responsive immune infiltrate; as such, treatments enhancing immune infiltration and preventing immunosuppression are of critical need. We previously generated αPD-1 resistant variants of the murine HNSCC model MEER. While entirely αPD-1 resistant, these tumors regress after single dose of oncolytic vaccinia virus (VV). We then generated a VV-resistant MEER line to dissect the immunologic features of sensitive and resistant tumors. While treatment of both tumor types induced immune infiltration and IFNγ, we found a defining feature of resistance was elevation of immunosuppressive cytokines like TGFβ, which blunted IFNγ signaling, especially in regulatory T cells. We engineered VV to express a genetically encoded TGFβRII inhibitor. Inhibitor-expressing VV produced regressions in resistant tumor models and showed impressive synergy with checkpoint blockade. Importantly, tumor-specific, viral delivery of TGFβ inhibition had no toxicities associated with systemic TGFβ/TGFβR inhibition. Our data suggest that aside from stimulating immune infiltration, oncolytic viruses are attractive means to deliver agents to limit immunosuppression in cancer.

Theoretical analysis for low voltage ride through capability in doubly-fed induction generator-based wind turbines with stator resistive hardware model

Theoretical analysis for low voltage ride through capability in doubly-fed induction generator-based wind turbines with stator resistive hardware model

Isoalantolactone Suppresses Glycolysis and Resensitizes Cisplatin-Based Chemotherapy in Cisplatin-Resistant Ovarian Cancer Cells.

Cisplatin is a potent chemotherapeutic drug for ovarian cancer (OC) treatment. However, its efficacy is significantly limited due to the development of cisplatin resistance. Although the acquisition of cisplatin resistance is a complex process involving various molecular alterations within cancer cells, the increased reliance of cisplatin-resistant cells on glycolysis has gained increasing attention. Isoalantolactone, a sesquiterpene lactone isolated from Inula helenium L., possesses various pharmacological properties, including anticancer activity. In this study, isoalantolactone was investigated as a potential glycolysis inhibitor to overcome cisplatin resistance in OC. Isoalantolactone effectively targeted key glycolytic enzymes (e.g., lactate dehydrogenase A, phosphofructokinase liver type, and hexokinase 2), reducing glucose consumption and lactate production in cisplatin-resistant OC cells (specifically A2780 and SNU-8). Importantly, it also sensitized these cells to cisplatin-induced apoptosis. Isoalantolactone-cisplatin treatment regulated mitogen-activated protein kinase and AKT pathways more effectively in cisplatin-resistant cells than individual treatments. In vivo studies using cisplatin-sensitive and resistant OC xenograft models revealed that isoalantolactone, either alone or in combination with cisplatin, significantly suppressed tumor growth in cisplatin-resistant tumors. These findings highlight the potential of isoalantolactone as a novel glycolysis inhibitor for treating cisplatin-resistant OC. By targeting the dysregulated glycolytic pathway, isoalantolactone offers a promising approach to overcoming drug resistance and enhancing the efficacy of cisplatin-based therapies.

BTK inhibition potentiates anti-PD-L1 treatment in murine melanoma: potential role for MDSC modulation in immunotherapy.

Myeloid-derived suppressor cells (MDSC) have been linked to loss of immune effector cell function through a variety of mechanisms such as the generation of reactive oxygen and nitrogen species and the production of inhibitory cytokines. Our group has shown that signaling through Bruton's tyrosine kinase (BTK) is important for MDSC function. Ibrutinib is an orally administered targeted agent that inhibits BTK activation and is currently used for the treatment of B cell malignancies. Using a syngeneic murine model of melanoma, the effect of BTK inhibition with ibrutinib on the therapeutic response to systemic PD-L1 blockade was studied. BTK was expressed by murine MDSC and their activation was inhibited by ibrutinib. Ibrutinib was not directly cytotoxic to cancer cells in vitro, but it inhibited BTK activation in MDSC and reduced expression of inducible nitric oxide synthase (NOS2) and production of nitric oxide. Ibrutinib treatments decreased the levels of circulating MDSC in vivo and increased the therapeutic efficacy of anti-PD-L1 antibody treatment. Gene expression profiling showed that ibrutinib decreased Cybb (NOX2) signaling, and increased IL-17 signaling (upregulating downstream targets Mmp9, Ptgs2, and S100a8). These results suggest that further exploration of MDSC inhibition could enhance the immunotherapy of advanced melanoma.PrécisInhibition of Bruton's tyrosine kinase, a key enzyme in myeloid cellular function, improves therapeutic response to an anti-PD-L1 antibody in an otherwise fairly resistant murine melanoma model.

Defining the spatial distribution of extracellular adenosine revealed a myeloid-dependent immunosuppressive microenvironment in pancreatic ductal adenocarcinoma

BackgroundThe prognosis for patients with pancreatic ductal adenocarcinoma (PDAC) remains extremely poor. It has been suggested that the adenosine pathway contributes to the ability of PDAC to evade the immune...

Mammalian SWI/SNF chromatin remodeling complexes promote tyrosine kinase inhibitor resistance in EGFR-mutant lung cancer.

Acquired resistance to tyrosine kinase inhibitors (TKI), such as osimertinib used to treat EGFR-mutant lung adenocarcinomas, limits long-term efficacy and is frequently caused by non-genetic mechanisms. Here, we define the chromatin accessibility and gene regulatory signatures of osimertinib sensitive and resistant EGFR-mutant cell and patient-derived models and uncover a role for mammalian SWI/SNF chromatin remodeling complexes in TKI resistance. By profiling mSWI/SNF genome-wide localization, we identify both shared and cancer cell line-specific gene targets underlying the resistant state. Importantly, genetic and pharmacologic disruption of the SMARCA4/SMARCA2 mSWI/SNF ATPases re-sensitizes a subset of resistant models to osimertinib via inhibition of mSWI/SNF-mediated regulation of cellular programs governing cell proliferation, epithelial-to-mesenchymal transition, epithelial cell differentiation, and NRF2 signaling. These data highlight the role of mSWI/SNF complexes in supporting TKI resistance and suggest potential utility of mSWI/SNF inhibitors in TKI-resistant lung cancers.