Hematopoietic progenitor kinase 1 down-regulates the oncogenic receptor tyrosine kinase AXL in pancreatic cancer.

The oncogenic receptor tyrosine kinase AXL is overexpressed in cancer and plays an important role in carcinomas of multiple organs. However, the mechanisms of AXL overexpression in cancer remain unclear. In this study, using HEK293T, Panc-1, and Panc-28 cells and samples of human pancreatic intraepithelial neoplasia (PanIN), along with several biochemical approaches and immunofluorescence microscopy analyses, we sought to investigate the mechanisms that regulate AXL over-expression in pancreatic ductal adenocarcinoma (PDAC). We found that AXL interacts with hematopoietic progenitor kinase 1 (HPK1) and demonstrate that HPK1 down-regulates AXL and decreases its half-life. The HPK1-mediated AXL degradation was inhibited by the endocytic pathway inhibitors leupeptin, bafilomycin A1, and monensin. HPK1 accelerated the movement of AXL from the plasma membrane to endosomes in pancreatic cancer cells treated with the AXL ligand growth arrest-specific 6 (GAS6). Moreover, HPK1 increased the binding of AXL to the Cbl proto-oncogene (c-Cbl); promoted AXL ubiquitination; decreased AXL-mediated signaling, including phospho-AKT and phospho-ERK signaling; and decreased the invasion capability of PDAC cells. Importantly, we show that AXL expression inversely correlates with HPK1 expression in human PanINs and that patients whose tumors have low HPK1 and high AXL expression levels have shorter survival than those with low AXL or high HPK1 expression (p < 0.001). Our results suggest that HPK1 is a tumor suppressor that targets AXL for degradation via the endocytic pathway. HPK1 loss of function may contribute to AXL overexpression and thereby enhance AXL-dependent downstream signaling and tumor invasion in PDAC.

Development of potent small-molecule inhibitors to drug the undruggable steroid receptor coactivator-3.

Protein-protein interactions (PPIs) play a central role in most biological processes, and therefore represent an important class of targets for therapeutic development. However, disrupting PPIs using small-molecule inhibitors (SMIs) is challenging and often deemed as "undruggable." We developed a cell-based functional assay for high-throughput screening to identify SMIs for steroid receptor coactivator-3 (SRC-3 or AIB1), a large and mostly unstructured nuclear protein. Without any SRC-3 structural information, we identified SI-2 as a highly promising SMI for SRC-3. SI-2 meets all of the criteria of Lipinski's rule [Lipinski et al. (2001) Adv Drug Deliv Rev 46(1-3):3-26] for a drug-like molecule and has a half-life of 1 h in a pharmacokinetics study and a reasonable oral availability in mice. As a SRC-3 SMI, SI-2 can selectively reduce the transcriptional activities and the protein concentrations of SRC-3 in cells through direct physical interactions with SRC-3, and selectively induce breast cancer cell death with IC50 values in the low nanomolar range (3-20 nM), but not affect normal cell viability. Furthermore, SI-2 can significantly inhibit primary tumor growth and reduce SRC-3 protein levels in a breast cancer mouse model. In a toxicology study, SI-2 caused minimal acute cardiotoxicity based on a hERG channel blocking assay and an unappreciable chronic toxicity to major organs based on histological analyses. We believe that this work could significantly improve breast cancer treatment through the development of "first-in-class" drugs that target oncogenic coactivators.

Precisely tunable engineering of sub-30 nm monodisperse oligonucleotide nanoparticles.

Advancement of RNAi therapies is mainly hindered by the development of efficient delivery vehicles. The ability to create small size (<30 nm) oligonucleotide nanoparticles is essential for many aspects of the delivery process but is often overlooked. In this report, we describe diblock star polymers that can reproducibly complex double-stranded oligonucleotides into monodisperse nanoparticles with 15, 23, or 30 nm in diameter. The polymer-nucleic acid nanoparticles have a core-shell architecture with dense PEG brush coating. We characterized these nanoparticles using ITC, DLS, FRET, FCS, TIRF, and TEM. In addition to small size, these nanoparticles have neutral zeta-potentials, making the presented polymer architecture a very attractive platform for investigation of yet poorly studied polyplex size range for siRNA and antisense oligonucleotide delivery applications.

Cyclooxygenase-2 blockade inhibits accumulation and function of myeloid-derived suppressor cells and restores T cell response after traumatic stress.

Myeloid-derived suppressor cells (MDSCs) play a crucial role in T cell dysfunction, which is related to poor outcome in patients with severe trauma. Cyclooxygenase-2 (Cox-2) contributes to immune disorder in trauma and infection via production of prostaglandin E2. However, the role of Cox-2 in the accumulation and function of MDSCs after traumatic stress has not been fully elucidated. In the present study, we treated murine trauma model with NS398, a selective Cox-2 inhibitor. Then the percentages of CD11b+/Gr-1+ cells, proliferation and apoptosis of CD4+ T cells were determined. Arginase activity and arginase-1 (Arg-1) protein expression of splenic CD11b+/Gr-1+ cells, and delayed-type hypersensitivity (DTH) response were analyzed. The results showed that Cox-2 blockade significantly decreased the percentages of CD11b+/Gr-1+ cells in the spleen and bone marrow 48 and 72 h after traumatic stress. NS398 inhibited arginase activity and down-regulated the Arg-1 expression of splenic CD11b+/Gr-1+ cells. Moreover, NS398 could promote proliferation and inhibit apoptosis of CD4+ T cells. It also restored DTH response of traumatic mice. Taken together, our data revealed that Cox-2 might play a pivotal role in the accumulation and function of MDSC after traumatic stress.

Lead Compound Development of SRC-3 Inhibitors with Improved Pharmacokinetic Properties and Anticancer Efficacy.

Steroid receptor coactivator 3 (SRC-3) is a critical mediator of many intracellular signaling pathways that are crucial for cancer proliferation and metastasis. In this study, we performed structure-activity relationship exploration and drug-like optimization of the hit compound SI-2, guided by in vitro/in vivo metabolism studies and cytotoxicity assays. Our efforts led to the discovery of two lead compounds, SI-10 and SI-12. Both compounds exhibit potent cytotoxicity against a panel of human cancer cell lines and demonstrate acceptable pharmacokinetic properties. A biotinylated estrogen response element pull-down assay demonstrated that SI-12 could disrupt the recruitment of SRC-3 and p300 in the estrogen receptor complex. Importantly, SI-10 and SI-12 significantly inhibited tumor growth and metastasis in vivo without appreciable acute toxicity. These results demonstrate the potential of SI-10 and SI-12 as drug candidates for cancer therapy, given their potent SRC-3 inhibition and promising pharmacokinetic and toxicity profiles.

Circular RNA MELK Promotes Chondrocyte Apoptosis and Inhibits Autophagy in Osteoarthritis by Regulating MYD88/NF-κB Signaling Axis through MicroRNA-497-5p.

Osteoarthritis (OA) is a rheumatic disease and its pathogenesis involves the dysregulation of noncoding RNAs. Therefore, the regulatory mechanism of circular RNA MELK (circMELK) was specified in this work. OA human cartilage tissue was collected, and circMELK, miR-497-5p, and myeloid differentiation factor 88 (MYD88) expression were examined. Human chondrocytes were stimulated with interleukin- (IL-) 1ß and interfered with vectors altering circMELK, miR-497-5p, and MyD88 expression to observe their effects on cell viability, cell cycle and apoptosis, autophagy, and inflammation. The binding relationship between RNAs was verified. The data presented that OA cartilage tissues presented raised circMELK and MYD88 and inhibited miR-497-5p expression. IL-1ß suppressed cell viability, prevented cell cycle, and induced apoptosis, autophagy, and inflammation of chondrocytes. Functionally, IL-1ß-induced changes of chondrocytes could be attenuated by suppressing circMELK or overexpressing miR-497-5p. circMELK acted as a sponge of miR-497-5p while miR-497-5p was a regulator of MYD88. MYD88 restricted the effect of overexpressing miR-497-5p on IL-1ß-stimulated chondrocytes. MYD88 triggered nuclear factor-kappaB (NF-κB) pathway activation. Shortly, CircMELK promotes chondrocyte apoptosis and inhibits autophagy in OA by regulating MYD88/NF-κB signaling axis through miR-497-5p. Our study proposes a new molecular mechanism for the development of OA.

Modified lumbopelvic fixation for sacral and L5 fractures associated with spinopelvic instability: a case report and introduction of the surgical technique.

Posterior lumbopelvic fixation with iliac screws is the most commonly used method for unstable spinopelvic injuries. It has certain limitations including inability to use distraction along the spinopelvic rod as an indirect reduction maneuver, need for complex 3-dimensional rod contouring and complications such as hardware prominence and soft tissue coverage. In the present case report, we described a surgical technique of lumbopelvic fixation with sacral alar screws for traumatic spinopelvic instability resulted from a unilateral Denis-III comminuted sacral fracture and the L5 burst fracture. On the opposite side of the sacral fracture, caudal screws were implanted into the pedicle of the S1, whereas on the side of sacral fracture, two sacral alar screws were placed parallel to the superior sacral endplate as well as the plane of sacroiliac joint. In addition, horizontal stabilization was conducted with cross-link connections to maintain the longitudinal traction. For sacral fracture associated with traumatic spinopelvic instability, this modified lumbopelvic fixation technique using sacral alar screws makes longitudinal reduction easier, requires less rod contouring, and reduces hardware prominence without compromising the stability.

The new core promoter element XCPE1 (X Core Promoter Element 1) directs activator-, mediator-, and TATA-binding protein-dependent but TFIID-independent RNA polymerase II transcription from TATA-less promoters.

The core promoter is a critical DNA element required for accurate transcription and regulation of transcription. Several core promoter elements have been previously identified in eukaryotes, but those cannot account for transcription from most RNA polymerase II-transcribed genes. Additional, as-yet-unidentified core promoter elements must be present in eukaryotic genomes. From extensive analyses of the hepatitis B virus X gene promoter, here we identify a new core promoter element, XCPE1 (the X gene core promoter element 1), that drives RNA polymerase II transcription. XCPE1 is located between nucleotides -8 and +2 relative to the transcriptional start site (+1) and has a consensus sequence of G/A/T-G/C-G-T/C-G-G-G/A-A-G/C(+1)-A/C. XCPE1 shows fairly weak transcriptional activity alone but exerts significant, specific promoter activity when accompanied by activator-binding sites. XCPE1 is also found in the core promoter regions of about 1% of human genes, particularly in poorly characterized TATA-less genes. Our in vitro transcription studies suggest that the XCPE1-driven transcription can be highly active in the absence of TFIID because it can utilize either free TBP or the complete TFIID complex. Our findings suggest the possibility of the existence of a TAF1 (TFIID)-independent transcriptional initiation mechanism that may be used by a category of TATA-less promoters in higher eukaryotes.

Quantitative Real-Time Imaging of Glutathione with Subcellular Resolution.

AIMS: Quantitative imaging of glutathione (GSH) with high spatial and temporal resolution is essential for studying the roles of GSH in redox biology. To study the long-standing question of compartmentalization of GSH, especially its distribution between the nucleus and cytosol, an organelle-targeted quantitative probe is needed. RESULTS: We developed a reversible reaction-based ratiometric fluorescent probe-HaloRT-that can quantitatively measure GSH dynamics with subcellular resolution in real time. Using HaloRT, we quantitatively measured the GSH concentrations in the nucleus and cytosol of HeLa cells and primary hepatocytes under different treatment conditions and found no appreciable concentration gradients between these two organelles. Innovation and Conclusion: We developed the first reversible ratiometric GSH probe that can be universally targeted to any organelle of interest. Taking advantage of this new tool, we provided definitive evidence showing that GSH concentrations are not significantly different between the nucleus and cytosol, challenging the view of nuclear compartmentalization of GSH.

SRC-3 inhibition blocks tumor growth of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant and lethal disease with few treatment options. Steroid receptor coactivator-3 (SRC-3, also known as NCOA3, AIB1, pCIP, ACTR, RAC3, TRAM1) sits at the nexus of many growth signaling pathways and has been pursued as a therapeutic target for breast, prostate and lung cancers. In this study, we find that SRC-3 is overexpressed in PDAC and inversely correlates with patient overall survival. Knockdown of SRC-3 reduces pancreatic cancer cell proliferation, migration and invasion in vitro. Additionally, inhibition of SRC-3 using either shRNA or a small molecule inhibitor can significantly inhibit tumor growth in orthotopic pancreatic cancer mouse models. Collectively, this study establishes SRC-3 as a promising therapeutic target for pancreatic cancer treatment.

[Analysis of emergency treatment in 4519 patients with multiple injuries].

OBJECTIVE: To investigate the clinical manifestations, treatment, complications, and prognosis of patients with multiple injuries. METHOD: The clinical data, including the causes of injury, treatment, complications, causes of death, and mortality rate, of 4519 patients were retrospectively analyzed. RESULTS: The major causes of injury were road traffic injury (2410 cases, 53.33%), violence injury (747 cases, 16.53%), and high falling injury (575 cases, 12.72%). The main involved positions included head (2247 cases, 18.71%), abdominal region and pelvis (2118 cases, 17.64%), and thoracic region (1853 cases, 15.43%). The major complications were shock (1497 cases, 33.13%). The main cause of death was sepsis with multiple organ dysfunction syndrome/failure (28 cases, 82.35%) after multiple injuries, significant higher than other causes in the same period (P<0.01). CONCLUSIONS: The multiple injuries have various causes of disease, and were complicated with their diverse clinical manifestations, numerous complications, and high mortalities. Further research on the integrated rescue mortality is required.

Quantitative real-time imaging of glutathione.

Glutathione plays many important roles in biological processes; however, the dynamic changes of glutathione concentrations in living cells remain largely unknown. Here, we report a reversible reaction-based fluorescent probe-designated as RealThiol (RT)-that can quantitatively monitor the real-time glutathione dynamics in living cells. Using RT, we observe enhanced antioxidant capability of activated neurons and dynamic glutathione changes during ferroptosis. RT is thus a versatile tool that can be used for both confocal microscopy and flow cytometry based high-throughput quantification of glutathione levels in single cells. We envision that this new glutathione probe will enable opportunities to study glutathione dynamics and transportation and expand our understanding of the physiological and pathological roles of glutathione in living cells.

Corrigendum: Quantitative real-time imaging of glutathione.

This corrects the article DOI: 10.1038/ncomms16087.

Steroid Receptor Coactivator-3 (SRC-3/AIB1) as a Novel Therapeutic Target in Triple Negative Breast Cancer and Its Inhibition with a Phospho-Bufalin Prodrug.

Triple negative breast cancer (TNBC) has the poorest prognosis of all types of breast cancer and currently lacks efficient targeted therapy. Chemotherapy is the traditional standard-of-care for TNBC, but is frequently accompanied by severe side effects. Despite the fact that high expression of steroid receptor coactivator 3 (SRC-3) is correlated with poor survival in estrogen receptor positive breast cancer patients, its role in TNBC has not been extensively investigated. Here, we show that high expression of SRC-3 correlates with both poor overall survival and post progression survival in TNBC patients, suggesting that SRC-3 can serve as a prognostic marker for TNBC. Furthermore, we demonstrated that bufalin, a SRC-3 small molecule inhibitor, when introduced even at nM concentrations, can significantly reduce TNBC cell viability and motility. However, because bufalin has minimal water solubility, its in vivo application is limited. Therefore, we developed a water soluble prodrug, 3-phospho-bufalin, to facilitate its in vivo administration. In addition, we demonstrated that 3-phospho-bufalin can effectively inhibit tumor growth in an orthotopic TNBC mouse model, suggesting its potential application as a targeted therapy for TNBC treatment.

Quantitative imaging of glutathione in live cells using a reversible reaction-based ratiometric fluorescent probe.

Glutathione (GSH) plays an important role in maintaining redox homeostasis inside cells. Currently, there are no methods available to quantitatively assess the GSH concentration in live cells. Live cell fluorescence imaging revolutionized the field of cell biology and has become an indispensable tool in current biological studies. In order to minimize the disturbance to the biological system in live cell imaging, the probe concentration needs to be significantly lower than the analyte concentration. Because of this, any irreversible reaction-based GSH probe can only provide qualitative results within a short reaction time and will exhibit maximum response regardless of the GSH concentration if the reaction is completed. A reversible reaction-based probe with an appropriate equilibrium constant allows measurement of an analyte at much higher concentrations and, thus, is a prerequisite for GSH quantification inside cells. In this contribution, we report the first fluorescent probe-ThiolQuant Green (TQ Green)-for quantitative imaging of GSH in live cells. Due to the reversible nature of the reaction between the probe and GSH, we are able to quantify mM concentrations of GSH with TQ Green concentrations as low as 20 nM. Furthermore, the GSH concentrations measured using TQ Green in 3T3-L1, HeLa, HepG2, PANC-1, and PANC-28 cells are reproducible and well correlated with the values obtained from cell lysates. TQ Green imaging can also resolve the changes in GSH concentration in PANC-1 cells upon diethylmaleate (DEM) treatment. In addition, TQ Green can be conveniently applied in fluorescence activated cell sorting (FACS) to measure GSH level changes. Through this study, we not only demonstrate the importance of reaction reversibility in designing quantitative reaction-based fluorescent probes but also provide a practical tool to facilitate redox biology studies.

Bufalin is a potent small-molecule inhibitor of the steroid receptor coactivators SRC-3 and SRC-1.

Virtually all transcription factors partner with coactivators that recruit chromatin remodeling factors and interact with the basal transcription machinery. Coactivators have been implicated in cancer cell proliferation, invasion, and metastasis, including the p160 steroid receptor coactivator (SRC) family composed of SRC-1 (NCOA1), SRC-2 (TIF2/GRIP1/NCOA2), and SRC-3 (AIB1/ACTR/NCOA3). Given their broad involvement in many cancers, they represent candidate molecular targets for new chemotherapeutics. Here, we report on the results of a high-throughput screening effort that identified the cardiac glycoside bufalin as a potent small-molecule inhibitor for SRC-3 and SRC-1. Bufalin strongly promoted SRC-3 protein degradation and was able to block cancer cell growth at nanomolar concentrations. When incorporated into a nanoparticle delivery system, bufalin was able to reduce tumor growth in a mouse xenograft model of breast cancer. Our work identifies bufalin as a potentially broad-spectrum small-molecule inhibitor for cancer.

Overexpression of receptor tyrosine kinase Axl promotes tumor cell invasion and survival in pancreatic ductal adenocarcinoma.

BACKGROUND: The receptor tyrosine kinase Axl has been reported to be overexpressed in a variety of human cancers. Although previous studies have identified the role of Axl in the transformation, proliferation, survival, and invasion in cancers, the expression and functions of Axl in pancreatic cancer have not been studied in detail. METHODS: The expression of Axl protein in 12 pancreatic cancer cell lines and 54 patient samples of stage II pancreatic ductal adenocarcinoma (PDA) and their paired non-neoplastic pancreatic tissue samples were examined. Using univariate and multivariate analysis, Axl expression was correlated with survival and other clinicopathologic features. To examine Axl functions in PDA, the effects of Axl knockdown on the invasion ability and radiation-induced apoptosis in PDA cell lines were measured. RESULTS: Axl was overexpressed in 38 of 54 (70%) stage II PDA samples and 9 of 12 (75%) PDA cell lines. Axl overexpression was associated with higher frequencies of distant metastasis and poor overall and recurrence-free survivals (P = .03 and P = .04, respectively) independent of tumor size and stage or lymph node status in patients with stage II PDA. Knockdown of Axl expression in PDA cells abolished Gas6-mediated Akt activation, decreased invasion, and increased radiation-induced PARP cleavage and the percentage of apoptosis. CONCLUSIONS: This study showed that Gas6 and Axl are frequently overexpressed in PDA cells and are associated with a poor prognosis in patients with stage II PDA. Axl promotes the invasion and survival of PDA cells. Therefore, targeting the Axl signaling pathway may represent a new approach to the treatment of PDA.

High levels of nucleolar expression of nucleolin are associated with better prognosis in patients with stage II pancreatic ductal adenocarcinoma.

PURPOSE: Nucleolin is a major nucleolar protein that has been shown to be overexpressed in rapidly dividing cells and plays an essential role in cell proliferation and survival. However, the expression and significance of nucleolin in pancreatic ductal adenocarcinoma (PDA) have not been studied. EXPERIMENTAL DESIGN: We used a tissue microarray consisting of 1.0-mm cores of tumor and paired nonneoplastic pancreatic tissue from 69 pancreaticoduodenectomy specimens with stage II PDA. Nucleolin expression was evaluated by immunohistochemistry and scored quantitatively by image analysis. Nucleolin expression was classified as nucleolin-high or nucleolin-low using the median nucleolin labeling index of 3.5% as cutoff. Staining results were correlated with clinicopathologic features and survival. RESULTS: Both PDAs and PDA cell lines showed nucleolar staining for nucleolin. Nucleolin expression was higher in PDAs and PDA cell lines than in nonneoplastic ductal epithelial cells. Among the 69 stage II PDAs, 34 (49%) were nucleolin-high. The median overall survival was 65.2 +/- 16.3 months for patients who had nucleolin-high PDAs compared with 19.5 +/- 3.3 months for patients whose tumors were nucleolin-low (P = 0.03, log-rank method). No significant correlation between nucleolin expression and other clinicopathologic parameters was found. In multivariate analysis, nucleolin expression was a prognostic factor for overall survival in patients with stage II PDA independent of patient's age, gender, tumor size, differentiation, and lymph node status. CONCLUSIONS: Nucleolin was overexpressed in PDAs and PDA cell lines. A high level of nucleolar expression of nucleolin was an independent prognostic marker for better survival for patients with stage II PDAs.

Proteasome-mediated degradation and functions of hematopoietic progenitor kinase 1 in pancreatic cancer.

Hematopoietic progenitor kinase 1 (HPK1) regulates stress responses, proliferation, and apoptosis in hematopoietic cells. In this study, we examined the expression, regulation, and functions of HPK1 in pancreatic ductal adenocarcinomas (PDA). We found that loss of HPK1 protein expression correlated significantly with the progression of pancreatic intraepithelial neoplasias (P = 0.001) and development of invasive PDA. Similarly, HPK1 protein was not expressed in any of eight PDA cell lines examined but was expressed in immortalized human pancreatic duct epithelial (HPDE) cells. There was no difference in HPK1 mRNA levels in PDA cell lines or primary PDA compared with those in HPDE cells or ductal epithelium in chronic pancreatitis and normal pancreas, respectively. Treatment of Panc-1 cells with a proteasome inhibitor, MG132, increased the HPK1 protein levels in a dose-dependent manner, suggesting that alteration in proteasome activity contributes to the loss of HPK1 protein expression in pancreatic cancer. Like the endogenous HPK1, both wild-type HPK1 and its kinase-dead mutant, HPK1-M46, overexpressed in Panc-1 cells, were also targeted by proteasome-mediated degradation. After MG132 withdrawal, wild-type HPK1 protein expression was markedly decreased within 24 hours, but kinase-dead HPK1 mutant protein expression was sustained for up to 96 hours. Therefore, HPK1 kinase activities were required for the loss of HPK1 protein in PDAs. Furthermore, restoring wild-type HPK1 protein in PDA cells led to the increase in p21 and p27 protein expression and cell cycle arrest. Thus, HPK1 may function as a novel tumor suppressor and its loss plays a critical role in pancreatic cancer.

Constitutive activation of c-Jun N-terminal kinase correlates with histologic grade and EGFR expression in diffuse gliomas.

The c-Jun NH2-terminal kinase (JNK), which belongs to mitogen-activated protein kinase family, plays a major role in apoptosis in various cell types. JNK activation, however, also contributes to proliferation, survival, and tumorigenesis in some tumors, including gliomas. In this study, we used an immunohistochemical approach to examine the activation status of JNK of 226 gliomas in a high-density tissue microarray comprising all WHO codified WHO diffuse glioma subtypes and grades. The results were correlated with grade and EGFR expression status. Constitutively activated JNK (pJNK) was detected in 90.5%, 62.9% and 17.5% of WHO grade IV, III and II gliomas, respectively (p < 0.001). pJNK expression was not detected in the astrocytes or oligodendrocytes of any of 10 normal cerebral and cerebellar brain tissue samples. Among the 76 diffuse gliomas that exhibited EGFR expression, 63 (82.9%) were positive for pJNK. In contrast, only 50% (36/72) of the gliomas that were negative for EGFR were positive for pJNK (p < 0.0001). Overexpression of EGFR vIII in U87 cells or EGF treatment of U87-EGFR stable cells led to marked increase in JNK activation compared to parental U87 cells. Our data thus provide strong support for the hypothesis that JNK activation plays a role in the tumorigenesis and/or progression of diffuse gliomas, and suggests that EGFR is involved in constitutive JNK activation in diffuse gliomas. The ability to inhibit JNK activation might confer increased sensitivity to therapeutic modalities targeting this pathway.