Adverse pharmacokinetic interactions between illicit substances and clinical drugs.

Adverse pharmacokinetic interactions between illicit substances and clinical drugs are of a significant health concern. Illicit substances are taken by healthy individuals as well as by patients with medical conditions such as mental illnesses, acquired immunodeficiency syndrome, diabetes mellitus and cancer. Many individuals that use illicit substances simultaneously take clinical drugs meant for targeted treatment. This concomitant usage can lead to life-threatening pharmacokinetic interactions between illicit substances and clinical drugs. Optimal levels and activity of drug-metabolizing enzymes and drug-transporters are crucial for metabolism and disposition of illicit substances as well as clinical drugs. However, both illicit substances and clinical drugs can induce changes in the expression and/or activity of drug-metabolizing enzymes and drug-transporters. Consequently, with concomitant usage, illicit substances can adversely influence the therapeutic outcome of coadministered clinical drugs. Likewise, clinical drugs can adversely affect the response of coadministered illicit substances. While the interactions between illicit substances and clinical drugs pose a tremendous health and financial burden, they lack a similar level of attention as drug-drug, food-drug, supplement-drug, herb-drug, disease-drug, or other substance-drug interactions such as alcohol-drug and tobacco-drug interactions. This review highlights the clinical pharmacokinetic interactions between clinical drugs and commonly used illicit substances such as cannabis, cocaine and 3, 4-Methylenedioxymethamphetamine (MDMA). Rigorous efforts are warranted to further understand the underlying mechanisms responsible for these clinical pharmacokinetic interactions. It is also critical to extend the awareness of the life-threatening adverse interactions to both health care professionals and patients.

Mg2+/Mn2+-dependent phosphatase 1A is involved in regulating pregnane X receptor-mediated cytochrome p450 3A4 gene expression.

Variations in the expression of human pregnane X receptor (hPXR)-mediated cytochrome p450 3A4 (CYP3A4) in liver can alter therapeutic response to a variety of drugs and may lead to potential adverse drug interactions. We sought to determine whether Mg(2+)/Mn(2+)-dependent phosphatase 1A (PPM1A) regulates hPXR-mediated CYP3A4 expression. PPM1A was found to be coimmunoprecipitated with hPXR. Genetic or pharmacologic activation of PPM1A led to a significant increase in hPXR transactivation of CYP3A4 promoter activity. In contrast, knockdown of endogenous PPM1A not only attenuated hPXR transactivation, but also increased proliferation of HepG2 human liver carcinoma cells, suggesting that PPM1A expression levels regulate hPXR, and that PPM1A expression is regulated in a proliferation-dependent manner. Indeed, PPM1A expression and hPXR transactivation were found to be significantly reduced in subconfluent HepG2 cells compared with confluent HepG2 cells, suggesting that both PPM1A expression and hPXR-mediated CYP3A4 expression may be downregulated in proliferating livers. Elevated PPM1A levels led to attenuation of hPXR inhibition by tumor necrosis factor-α and cyclin-dependent kinase-2, which are known to be upregulated and essential during liver regeneration. In mouse regenerating livers, similar to subconfluent HepG2 cells, expression of both PPM1A and the mouse PXR target gene cyp3a11 was found to be downregulated. Our results show that PPM1A can positively regulate PXR activity by counteracting PXR inhibitory signaling pathways that play a major role in liver regeneration. These results implicate a novel role for PPM1A in regulating hPXR-mediated CYP3A4 expression in hepatocytes and may explain a mechanism for CYP3A repression in regenerating livers.

Utilizing genomic prediction to boost hybrid performance in a sweet corn breeding program.

Sweet corn breeding programs, like field corn, focus on the development of elite inbred lines to produce commercial hybrids. For this reason, genomic selection models can help the in silico prediction of hybrid crosses from the elite lines, which is hypothesized to improve the test cross scheme, leading to higher genetic gain in a breeding program. This study aimed to explore the potential of implementing genomic selection in a sweet corn breeding program through hybrid prediction in a within-site across-year and across-site framework. A total of 506 hybrids were evaluated in six environments (California, Florida, and Wisconsin, in the years 2020 and 2021). A total of 20 traits from three different groups were measured (plant-, ear-, and flavor-related traits) across the six environments. Eight statistical models were considered for prediction, as the combination of two genomic prediction models (GBLUP and RKHS) with two different kernels (additive and additive + dominance), and in a single- and multi-trait framework. Also, three different cross-validation schemes were tested (CV1, CV0, and CV00). The different models were then compared based on the correlation between the estimated breeding values/total genetic values and phenotypic measurements. Overall, heritabilities and correlations varied among the traits. The models implemented showed good accuracies for trait prediction. The GBLUP implementation outperformed RKHS in all cross-validation schemes and models. Models with additive plus dominance kernels presented a slight improvement over the models with only additive kernels for some of the models examined. In addition, models for within-site across-year and across-site performed better in the CV0 than the CV00 scheme, on average. Hence, GBLUP should be considered as a standard model for sweet corn hybrid prediction. In addition, we found that the implementation of genomic prediction in a sweet corn breeding program presented reliable results, which can improve the testcross stage by identifying the top candidates that will reach advanced field-testing stages.

A novel preclinical model of craniospinal irradiation in pediatric diffuse midline glioma demonstrates decreased metastatic disease.

Background: Diffuse midline glioma (DMG) is an aggressive pediatric central nervous system tumor with strong metastatic potential. As localized treatment of the primary tumor improves, metastatic disease is becoming a more important factor in treatment. We hypothesized that we could model craniospinal irradiation (CSI) through a DMG patient-derived xenograft (PDX) model and that CSI would limit metastatic tumor. Methods: We used a BT245 murine orthotopic DMG PDX model for this work. We developed a protocol and specialized platform to deliver craniospinal irradiation (CSI) (4 Gy x2 days) with a pontine boost (4 Gy x2 days) and compared metastatic disease by pathology, bioluminescence, and MRI to mice treated with focal radiation only (4 Gy x4 days) or no radiation. Results: Mice receiving CSI plus boost showed minimal spinal and brain leptomeningeal metastatic disease by bioluminescence, MRI, and pathology compared to mice receiving radiation to the pons only or no radiation. Conclusion: In a DMG PDX model, CSI+boost minimizes tumor dissemination compared to focal radiation. By expanding effective DMG treatment to the entire neuraxis, CSI has potential as a key component to combination, multimodality treatment for DMG designed to achieve long-term survival once novel therapies definitively demonstrate improved local control.

Interplay between the Cannabinoid System and microRNAs in Cancer.

Cancer patients often use cannabinoids for alleviating symptoms induced by cancer pathogenesis and cancer treatment. This use of cannabinoids can have unexpected effects in cancer patients depending on the cancer type, resulting in either beneficial (e.g., anticancer) or adverse (e.g., oncogenic) effects. While cannabinoids can enhance the growth and progression of some cancers, they can also suppress the growth and progression of other cancers. However, the underlying mechanisms of such differential effects are poorly understood. miRNAs have been shown to be involved in driving the hallmarks of cancer, affecting cancer growth and progression as well as cancer therapy response. Although the understanding of the effects of cannabinoids and miRNAs as they relate to cancer continues to improve, the interplay between cannabinoid system and miRNAs in cancer pathogenesis and cancer treatment response is poorly understood. Investigation of such interactions between the cannabinoid system and miRNAs could provide novel insights into the underlying mechanisms of the differential effects of cannabinoids in cancer and can help predict and improve the prognosis of cancer patients.

Gefitinib Inhibits Rifampicin-Induced CYP3A4 Gene Expression in Human Hepatocytes.

During multidrug combination chemotherapy, activation of the nuclear receptor and the transcription factor human pregnane xenobiotic receptor (hPXR) has been shown to play a role in the development of chemoresistance. Mechanistically, this could occur due to the cancer drug activation of hPXR and the subsequent upregulation of hPXR target genes such as the drug metabolism enzyme, cytochrome P450 3A4 (CYP3A4). In the context of hPXR-mediated drug resistance, hPXR antagonists would be useful adjuncts to PXR-activating chemotherapy. However, there are currently no clinically approved hPXR antagonists in the market. Gefitinib (GEF), a tyrosine kinase inhibitor used for the treatment of advanced non-small-cell lung cancer and effectively used in combinational chemotherapy treatments, is a promising candidate owing to its hPXR ligand-like features. We, therefore, investigated whether GEF would act as an hPXR antagonist when combined with a known hPXR agonist, rifampicin (RIF). At therapeutically relevant concentrations, GEF successfully inhibited the RIF-induced upregulation of endogenous CYP3A4 gene expression in human primary hepatocytes and human hepatocells. Additionally, GEF inhibited the RIF induction of hPXR-mediated CYP3A4 promoter activity in HepG2 human liver carcinoma cells. The computational modeling of molecular docking predicted that GEF could bind to multiple sites on hPXR including the ligand-binding pocket, allowing for potential as a direct antagonist as well as an allosteric inhibitor. Indeed, GEF bound to the ligand-binding domain of the hPXR in cell-free assays, suggesting that GEF directly interacts with the hPXR. Taken together, our results suggest that GEF, at its clinically relevant therapeutic concentration, can antagonize the hPXR agonist-induced CYP3A4 gene expression in human hepatocytes. Thus, GEF could be a potential candidate for use in combinational chemotherapies to combat hPXR agonist-induced chemoresistance. Further studies are warranted to determine whether GEF has sufficient hPXR inhibitor abilities to overcome the hPXR agonist-induced chemoresistance.

Acute Psychosis Due to Anti-N-Methyl D-Aspartate Receptor Encephalitis Following COVID-19 Vaccination: A Case Report.

Anti-N-methyl D-aspartate (NMDA) receptor (anti-NMDAR) encephalitis has been reported after SARS-CoV-2 infection, but not after SARS-CoV-2 vaccination. We report the first known case of anti-NMDAR encephalitis after SARS-CoV-2 immunization in a young female presenting with acute psychosis, highlighting a rare potential immunological complication of vaccination against SARS-CoV-2 that is currently being distributed worldwide. The patient presented initially with anxiety and hypochondriacal delusions which progressed to psychosis and catatonia but returned to baseline with aggressive immunomodulatory therapy consisting of intravenous immunoglobulin, high-dose glucocorticoids, and rituximab. This study highlights that the workup of acute psychosis should include establishing a history of recent vaccination followed by a thorough neurological assessment, including for anti-NMDAR antibodies in blood and cerebrospinal fluid.

A clinically relevant combination treatment with doxorubicin and cyclophosphamide does not induce hepatotoxicity in C57BL/6J mice.

BACKGROUND AND AIM: Chronic exposure to chemotherapeutics can lead to severe adverse events including hepatotoxicity. A combination chemotherapy regimen of doxorubicin (DOX) and cyclophosphamide (CPS) is employed in treatment of several cancers such as leukemia, lymphoma, and breast cancer. It is not well understood whether a combination therapy of DOX and CPS can induce hepatotoxicity. We therefore sought to determine whether co-administration of DOX and CPS at their clinically relevant doses and frequency results in hepatotoxicity. METHODS: Male C57BL/6J mice received one intraperitoneal injection of saline or DOX-2mg /kg and CPS-50mg/kg once a week for 4 weeks. After the treatment period, liver histology and various serum biomarkers of hepatotoxicity were assessed. RESULTS: Co-treatment of DOX and CPS did not alter the serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin, albumin, globulin, or total protein. Similarly, co-administration of DOX and CPS did not result in a noticeable change in liver histology. However, it was notable that the concomitant treatment with DOX and CPS resulted in a significant increase in serum levels of aspartate aminotransferase (AST). Elevated serum AST levels were also associated with increased serum creatinine kinase (CK) levels, suggesting that the elevated serum AST levels are likely due to muscle injury following the co-administration of DOX and CPS. CONCLUSION: Taken together, our results, for the first time, suggest that co-administration of DOX and CPS, at their clinically relevant doses and frequency does not induce a significant hepatotoxicity in the mice.

Oroxylum indicum extract, at a physiologically relevant dosage, does not induce hepatotoxicity in C57BL/6J mice.

BACKGROUND: Botanical supplements have been proven to provide beneficial health effects. However, they can induce unintended adverse events such as hepatotoxicity. Oroxylum indicum extract (OIE, Sabroxy®) has several health benefits including anti-inflammatory, anti-arthritic, antifungal, antibacterial, and neuroprotective effects. It is currently unknown whether OIE has the potential to induce hepatotoxicity. PURPOSE: In the current study, we sought to determine whether OIE can induce hepatotoxicity in C57BL/6J mouse model. METHODS: The male mice were fed powdered rodent food (control group) or powdered rodent food mixed with OIE (Sabroxy®, 500mg/kg) daily for 4 weeks. Following the treatment, we assessed liver histology and serum levels of biomarkers commonly associated with liver damage, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). RESULTS: No significant alterations were observed in liver histology, and serum levels of ALT, AST, ALP, bilirubin, albumin, globulin and total protein in the OIE fed mice compared to the control mice. CONCLUSION: Taken together, our results suggest that OIE, when fed at its physiologically relevant dosage, does not induce hepatotoxicity in C57BL/6J mice.

Deconvoluting Mechanisms of Acquired Resistance to RAF Inhibitors in BRAFV600E-Mutant Human Glioma.

PURPOSE: Selective RAF-targeted therapy is effective in some patients with BRAFV600E-mutated glioma, though emergent and adaptive resistance occurs through ill-defined mechanisms. EXPERIMENTAL DESIGN: Paired pre-/post- RAF inhibitor (RAFi)-treated glioma samples (N = 15) were obtained and queried for treatment-emergent genomic alterations using DNA and RNA sequencing (RNA-seq). Functional validation of putative resistance mechanisms was performed using established and patient-derived BRAFV600E-mutant glioma cell lines. RESULTS: Analysis of 15 tissue sample pairs identified 13 alterations conferring putative resistance were identified among nine paired samples (including mutations involving ERRFI1, BAP1, ANKHD1, and MAP2K1). We performed functional validation of mechanisms of resistance, including loss of NF1, PTEN, or CBL, in BRAFV600E-mutant glioma lines, and demonstrate they are capable of conferring resistance in vitro. Knockdown of CBL resulted in increased EGFR expression and phosphorylation, a possible mechanism for maintaining ERK signaling within the cell. Combination therapy with a MEKi or EGFR inhibitor was able to overcome resistance to BRAFi, in NF1 knockdown and CBL knockdown, respectively. Restoration of wild-type PTEN in B76 cells (PTEN-/-) restored sensitivity to BRAFi. We identified and validated CRAF upregulation as a mechanism of resistance in one resistant sample. RNA-seq analysis identified two emergent expression patterns in resistant samples, consistent with expression patterns of known glioma subtypes. CONCLUSIONS: Resistance mechanisms to BRAFi in glioma are varied and may predict effective precision combinations of targeted therapy, highlighting the importance of a personalized approach.

Comprehensive molecular characterization of pediatric radiation-induced high-grade glioma.

Radiation-induced high-grade gliomas (RIGs) are an incurable late complication of cranial radiation therapy. We performed DNA methylation profiling, RNA-seq, and DNA sequencing on 32 RIG tumors and an in vitro drug screen in two RIG cell lines. We report that based on DNA methylation, RIGs cluster primarily with the pediatric receptor tyrosine kinase I high-grade glioma subtype. Common copy-number alterations include Chromosome (Ch.) 1p loss/1q gain, and Ch. 13q and Ch. 14q loss; focal alterations include PDGFRA and CDK4 gain and CDKN2A and BCOR loss. Transcriptomically, RIGs comprise a stem-like subgroup with lesser mutation burden and Ch. 1p loss and a pro-inflammatory subgroup with greater mutation burden and depleted DNA repair gene expression. Chromothripsis in several RIG samples is associated with extrachromosomal circular DNA-mediated amplification of PDGFRA and CDK4. Drug screening suggests microtubule inhibitors/stabilizers, DNA-damaging agents, MEK inhibition, and, in the inflammatory subgroup, proteasome inhibitors, as potentially effective therapies.

Correlation of PPM1A Downregulation with CYP3A4 Repression in the Tumor Liver Tissue of Hepatocellular Carcinoma Patients.

BACKGROUND AND OBJECTIVE: In many patients with hepatocellular carcinoma (HCC), cytochrome P450 3A4 (CYP3A4) expression has been reported to be significantly reduced in the tumor liver tissue. Moreover, this CYP3A4 repression is associated with decreased CYP3A4-mediated drug metabolism in the tumor liver tissue. However, the underlying mechanisms of CYP3A4 repression are not fully understood. We have previously shown that Mg2+/Mn2+-dependent phosphatase 1A (PPM1A) positively regulates human pregnane X receptor (hPXR)-mediated CYP3A4 expression in a PPM1A expression-dependent manner. We sought to determine whether PPM1A expression is downregulated and whether PPM1A downregulation is correlated with CYP3A4 repression in the tumor liver tissue of HCC patients. METHODS: Quantitative RT-PCR and western blot analyses were performed to study mRNA and protein expression, respectively. Cell-based reporter gene assays were conducted to examine the hPXR transactivation of CYP3A4 promoter activity. RESULTS: Arginase-1 and glypican-3 gene expression studies confirmed that the tumor samples used in our study originate from HCC livers but not non-hepatocellular tumors. mRNA and protein expression of PPM1A and CYP3A4 was found to be significantly repressed in the tumor liver tissues compared to the matched non-tumor liver tissues. In the reporter gene assays, elevated PPM1A levels counteracted the inhibition of hPXR-mediated CYP3A4 promoter activity by signaling pathways that are upregulated in HCC, suggesting that decreased PPM1A levels in HCC could not fully counteract the hPXR-inhibiting signaling pathways. CONCLUSIONS: Together, these results are consistent with the conclusion that PPM1A downregulation in the tumor liver tissue of HCC patients correlates with CYP3A4 repression. Downregulation of PPM1A levels in the tumor liver tissue may contribute to reduced hPXR-mediated CYP3A4 expression, and provide a novel mechanism of CYP3A4 repression in the tumor liver tissue of HCC patients.

Crazy-Paving: A Computed Tomographic Finding of Coronavirus Disease 2019.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2. COVID-19 first occurred in Wuhan, China, in December 2019, and by March 2020 COVID-19 was declared a global pandemic. CASE PRESENTATION: We describe a case of a 52-year-old female with past medical history of asthma, type 2 diabetes, and previous tobacco use who presented to the emergency department with dyspnea and was found to be positive for COVID-19. We discuss the computed tomographic finding of "crazy-paving" pattern in the patient's lungs and the significance of this finding in COVID-19 patients. DISCUSSION: Emergency providers need to be aware of the different imaging characteristics of various stages of COVID-19 to appropriately treat, isolate, and determine disposition of COVID-19 infected patients. Ground-glass opacities are the earliest and most common imaging finding for COVID-19. Crazy-paving pattern is defined as thickened interlobular septa and intralobular lines superimposed on diffuse ground-glass opacities and should be recognized by emergency providers as a radiographic finding of progressive COVID-19.

Dysregulation of Endobiotic Homeostasis Mechanisms: Novel Insights into Adverse Pharmacokinetic Interactions between Illicit Substances and Clinical Drugs.

Many patients with a variety of medical conditions take illicit substances concomitantly with clinical drugs. This concomitant usage can lead to life-threatening adverse events. Despite the evidence that these adverse events can be caused by pharmacokinetic interactions, the underlying mechanisms are poorly understood. Investigation of mechanisms involved in dysregulation of endobiotic homeostasis during the concomitant usage of illicit substances with clinical drugs could provide novel insights into pharmacokinetic mechanisms of adverse interactions between illicit substances and clinical drugs.

Nothing Ventured, Nothing Gained: Regulations Cripple Potentially Life-Saving Research of Illicit Substances.

Modern day research, in an attempt to determine the potential therapeutic and adverse effects of illicit substances, is a growing field, but one that faces many regulatory challenges. Due to the potential abuse of illicit substances such as Cannabis, 3,4-methylenedioxymethamphetamine (MDMA), lysergic acid diethylamide (LSD) and psilocybin, regulations have been conceived with the intent of preventing harm and addiction. However, these regulations have also become a major barrier for the scientific community as they suffocate attempts of the scientists to acquire illicit substances for research purposes. Therefore, it is imperative to modify the current regulations of drug scheduling, leading to a reclassification of illicit substances that would allow for extensive testing in research settings. This reclassification effort could advance the potentially life-saving research of illicit substances.

Exportin 1 Inhibition Induces Nerve Growth Factor Receptor Expression to Inhibit the NF-κB Pathway in Preclinical Models of Pediatric High-Grade Glioma.

High-grade glioma (HGG) is the leading cause of cancer-related death among children. Selinexor, an orally bioavailable, reversible inhibitor of the nuclear export protein, exportin 1, is in clinical trials for a range of cancers, including HGG. It inhibits the NF-κB pathway and strongly induces the expression of nerve growth factor receptor (NGFR) in preclinical cancer models. We hypothesized that selinexor inhibits NF-κB via upregulation of NGFR. In HGG cells, sensitivity to selinexor correlated with increased induction of cell surface NGFR expression. Knocking down NGFR in HGG cells increased proliferation, anchorage-independent growth, stemness markers, and levels of transcriptionally available nuclear NF-κB not bound to IκB-α, while decreasing apoptosis and sensitivity to selinexor. Increasing IκB-α levels in NGFR knockdown cells restored sensitivity to selinexor. Overexpression of NGFR using cDNA reduced levels of free nuclear NF-κB, decreased stemness markers, and increased markers of cellular differentiation. In all HGG lines tested, selinexor decreased phosphorylation of NF-κB at serine 536 (a site associated with increased transcription of proliferative and inflammatory genes). Because resistance to selinexor monotherapy occurred in our in vivo model, we screened selinexor with a panel of FDA-approved anticancer agents. Bortezomib, a proteasome inhibitor that inhibits the NF-κB pathway through a different mechanism than selinexor, showed synergy with selinexor against HGG in vitro Our results help elucidate selinexor's mechanism of action and identify NGFR as a potential biomarker of its effect in HGG and in addition suggest a combination therapy strategy for these challenging tumors.

Preclinical and clinical investigation of intratumoral chemotherapy pharmacokinetics in DIPG using gemcitabine.

BACKGROUND: Hundreds of systemic chemotherapy trials in diffuse intrinsic pontine glioma (DIPG) have not improved survival, potentially due to lack of intratumoral penetration, which has not previously been assessed in humans. METHODS: We used gemcitabine as a model agent to assess DIPG intratumoral pharmacokinetics (PK) using mass spectrometry. RESULTS: In a phase 0 clinical trial of i.v. gemcitabine prior to biopsy in children newly diagnosed with DIPG by MRI, mean concentration in 4 biopsy cores in patient 1 (H3K27M diffuse midline glioma) was 7.65 µM. These compare favorably to levels for patient 2 (mean 3.85 µM, found to have an H3K27-wildtype low-grade glioma on histology), and from a similar study in adult glioblastoma (adjusted mean 3.48 µM). In orthotopic patient-derived xenograft (PDX) models of DIPG and H3K27M-wildtype pediatric glioblastoma, gemcitabine levels and clearance were similar in tumor, pons, and cortex and did not depend on H3K27 mutation status or tumor location. Normalized gemcitabine levels were similar in patient 1 and the DIPG PDX. CONCLUSIONS: These findings, while limited to one agent, provide preliminary evidence for the hypotheses that lack of intratumoral penetration is not why systemic chemotherapy has failed in DIPG, and orthotopic PDX models can adequately model intratumoral PK in human DIPG.

Correction: BPTF regulates growth of adult and pediatric high-grade glioma through the MYC pathway.

The original version of this Article omitted the following from the Acknowledgements: This work was supported by the Luke's Army Pediatric Cancer Research Fund St. Baldrick's Scholar Award. This has now been corrected in both the PDF and HTML versions of the Article.

BPTF regulates growth of adult and pediatric high-grade glioma through the MYC pathway.

High-grade gliomas (HGG) afflict both children and adults and respond poorly to current therapies. Epigenetic regulators have a role in gliomagenesis, but a broad, functional investigation of the impact and role of specific epigenetic targets has not been undertaken. Using a two-step, in vitro/in vivo epigenomic shRNA inhibition screen, we determine the chromatin remodeler BPTF to be a key regulator of adult HGG growth. We then demonstrate that BPTF knockdown decreases HGG growth in multiple pediatric HGG models as well. BPTF appears to regulate tumor growth through cell self-renewal maintenance, and BPTF knockdown leads these glial tumors toward more neuronal characteristics. BPTF's impact on growth is mediated through positive effects on expression of MYC and MYC pathway targets. HDAC inhibitors synergize with BPTF knockdown against HGG growth. BPTF inhibition is a promising strategy to combat HGG through epigenetic regulation of the MYC oncogenic pathway.

Gq-dependent signaling upregulates COX2 in glomerular podocytes.

Accumulating evidence suggests that upregulation of cyclooxygenase 2 (COX2) in glomerular podocytes promotes podocyte injury. Because Gq signaling activates calcineurin and calcineurin-dependent mechanisms are known to mediate COX2 expression, this study investigated the role of Gqalpha in promoting COX2 expression in podocytes. A constitutively active Gq alpha subunit tagged with the TAT HIV protein sequence was introduced into an immortalized podocyte cell line by protein transduction. This stimulated inositol trisphosphate production, activated an nuclear factor of activated T cells-responsive reporter construct, and enhanced levels of both COX2 mRNA and protein compared with cells treated with a Gq protein lacking the TAT sequence. Induction of COX2 was associated with increased prostaglandin E(2) production and podocyte death, both of which were attenuated by selective COX2 inhibition. In vivo, levels of COX2 mRNA and protein were significantly enhanced in podocytes from transgenic mice that expressed podocyte-targeted constitutively active Gqalpha compared with nontransgenic littermates. These data suggest that Gq-dependent signaling cascades stimulate calcineurin and, in turn, upregulate COX2 mRNA and protein, increase eicosanoid production, and cause podocyte injury.