Dr. Neal holds a medical degree and a doctoral degree in Tumor Cell Biology from Northwestern University in Chicago, Illinois. Subsequently, he completed a fellowship in oncology, rotating through the Dana-Farber Cancer Institute and Massachusetts General Hospital in Boston, Massachusetts. He is currently an Assistant Professor in the Division of Oncology at the Stanford Cancer Institute at Stanford University in Palo Alto, California. Dr Neal’s primary clinical interest is in thoracic oncology. In addition to maintaining an active practice, he focuses on the design and conduct of clinical trials involving targeted therapies and immunotherapy for lung cancer and mesothelioma. He has published dozens of articles in the field of thoracic oncology, including in Lancet Oncology, Nature Medicine, and the Journal of Clinical Oncology. He is a member of the International Association of the Study of Lung Cancer (IALSC), is a study chair and thoracic core committee member within the ECOG-ACRIN cooperative group, and has presented at a number of American Society of Clinical Oncology (ASCO) annual meetings.
- Cancer > Thoracic Oncology
- Thoracic Oncology
- Lung Cancer
- Medical Oncology
Medical Education:Northwestern University Feinberg School of Medicine (2004) IL
Fellowship:Dana Farber Cancer Institute Hematology Oncology Fellowship (2010) MA
Residency:Beth Israel Deaconess Medical Center (2007) MA
Board Certification: Medical Oncology, American Board of Internal Medicine (2010)
Board Certification: Internal Medicine, American Board of Internal Medicine (2007)
Current Research and Scholarly Interests
Non-small cell lung cancer (NSCLC) has historically been treated with combination chemotherapy. Over the last few years, molecular testing of NSCLC has revealed the presence of driving oncogenic mutations in a subset of tumors of adenocarcinoma histology, including EGFR, KRAS, and ALK. While chemotherapy is still effective for these patients, targeted therapies appear to be more specific with fewer side effects. For example, erlotinib treatment of EGFR mutant tumors results in better response rates and progression-free survival times than chemotherapy, and the investigational drug crizotinib is targeted against tumors harboring ALK translocations. My clinical and research interest is to apply evolving technologies to the diagnosis, characterization, and individualized treatment of NSCLC.
- A Case Series of Lengthy Progression-Free Survival With Pemetrexed-Containing Therapy in Metastatic Non-Small-Cell Lung Cancer Patients Harboring ROS1 Gene Rearrangements. Clinical lung cancer 2013; 14 (5): 592-595
A Patient With Anaplastic Lymphoma Kinase-Positive Non-Small Cell Lung Cancer With Development of Leptomeningeal Carcinomatosis While on Targeted Treatment With Crizotinib
JOURNAL OF THE NATIONAL COMPREHENSIVE CANCER NETWORK
2013; 11 (4): 389-394
Leptomeningeal carcinomatosis (LM) is an infrequent yet morbid and often fatal complication of non-small cell lung cancer (NSCLC). Management of LM is multimodal, often involving systemic chemotherapy, radiotherapy, and a variety of symptom management maneuvers to address elevated intracranial pressure, pain, and mood changes that can accompany the disease. It is increasingly recognized that tumors with actionable mutations in NSCLC, including epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) translocations, respond well to systemic therapy with tyrosine kinase inhibitors yet often progress in the central nervous system. More information is needed regarding the natural history and optimal management of LM in specific molecular subtypes of NSCLC. This case report summarizes the management of a patient with ALK-positive NSCLC who developed LM while on targeted treatment with crizotinib within the context of current NCCN Clinical Practice Guidelines in Oncology and recently published studies.
View details for Web of Science ID 000317543800006
View details for PubMedID 23584342
- A case series of NSCLC patients with different molecular characteristics and choroidal metastases: improvement in vision with treatment including pemetrexed and bevacizumab. Journal of thoracic oncology 2013; 8 (2): e17-8
Aflibercept in lung cancer
EXPERT OPINION ON BIOLOGICAL THERAPY
2013; 13 (1): 115-120
Angiogenesis, the recruitment and growth of blood vessels, is a process central to the growth of solid tumors. One of the key mediators of angiogenesis is the vascular endothelial growth factor (VEGF) family of ligands. An antibody to VEGF-A, bevacizumab, has demonstrated a survival benefit in conjunction with platinum-based doublet chemotherapy in non-small-cell lung cancer (NSCLC). Aflibercept (VEGF Trap) is a recombinant VEGF receptor-antibody protein fusion with higher affinity for VEGF-A than bevacizumab, plus affinity for VEGF-B and placental growth factor (PlGF). AREAS COVERED: This article reviews recent clinical trials investigating the role of aflibercept in the treatment of lung cancer, both published in the literature and those for which preliminary data have been presented at major scientific meetings. EXPERT OPINION: Aflibercept has proven Phase III efficacy in metastatic colorectal cancer, but in lung cancer, large clinical trials have not yielded positive results. There remains hope that identification of biomarkers of response will one day help select patients most likely to benefit from antiangiogenesis therapy.
View details for DOI 10.1517/14712598.2013.745847
View details for Web of Science ID 000312219700010
View details for PubMedID 23199019
- Targeting fibroblast growth factor receptor and discoidin domain receptor 2 in non-small-cell lung cancer. Journal of thoracic oncology 2012; 7 (16): S385-6
A Phase I Study of Erlotinib and Hydroxychloroquine in Advanced Non-Small-Cell Lung Cancer
JOURNAL OF THORACIC ONCOLOGY
2012; 7 (10): 1602-1608
This investigator-initiated study explores the safety, maximum tolerated dose, clinical response, and pharmacokinetics of hydroxychloroquine (HCQ) with and without erlotinib in patients with advanced non-small-cell lung cancer.Patients with prior clinical benefit from an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor were randomized to HCQ or HCQ plus erlotinib in a 3 + 3 dose-escalation schema.Twenty-seven patients were treated, eight with HCQ (arm A) and 19 with HCQ plus erlotinib (arm B). EGFR mutations were detected in 74% of the patients and 85% had received two or more prior therapies. Arm A had no dose-limiting toxicities, but the maximum tolerated dose was not reached as this arm closed early to increase overall study accrual. In arm B, one patient each experienced grade 3 rash, nail changes, skin changes, nausea, dehydration, and neutropenia; one had grade 4 anemia; and one developed fatal pneumonitis, all considered unrelated to HCQ. There were no dose-limiting toxicities, therefore the highest tested dose for HCQ with erlotinib 150 mg was 1000 mg daily. One patient had a partial response to erlotinib/HCQ, for an overall response rate of 5% (95% confidence interval, 1-25). This patient had an EGFR mutation and remained on therapy for 20 months. Administration of HCQ did not alter the pharmacokinetics of erlotinib.HCQ with or without erlotinib was safe and well tolerated. The recommended phase 2 dose of HCQ was 1000 mg when given in combination with erlotinib 150 mg.
View details for DOI 10.1097/JTO.0b013e318262de4a
View details for Web of Science ID 000308919400023
View details for PubMedID 22878749
- Complex Role of Histone Deacetylase Inhibitors in the Treatment of Non-Small-Cell Lung Cancer JOURNAL OF CLINICAL ONCOLOGY 2012; 30 (18): 2280-2282
Ipilimumab in Combination With Paclitaxel and Carboplatin As First-Line Treatment in Stage IIIB/IV Non-Small-Cell Lung Cancer: Results From a Randomized, Double-Blind, Multicenter Phase II Study
JOURNAL OF CLINICAL ONCOLOGY
2012; 30 (17): 2046-2054
Ipilimumab, which is an anti-cytotoxic T-cell lymphocyte-4 monoclonal antibody, showed a survival benefit in melanoma with adverse events (AEs) managed by protocol-defined guidelines. A phase II study in lung cancer assessed the activity of ipilimumab plus paclitaxel and carboplatin.Patients (N = 204) with chemotherapy-naive non-small-cell lung cancer (NSCLC) were randomly assigned 1:1:1 to receive paclitaxel (175 mg/m(2)) and carboplatin (area under the curve, 6) with either placebo (control) or ipilimumab in one of the following two regimens: concurrent ipilimumab (four doses of ipilimumab plus paclitaxel and carboplatin followed by two doses of placebo plus paclitaxel and carboplatin) or phased ipilimumab (two doses of placebo plus paclitaxel and carboplatin followed by four doses of ipilimumab plus paclitaxel and carboplatin).Treatment was administered intravenously every 3 weeks for ≤ 18 weeks (induction). Eligible patients continued ipilimumab or placebo every 12 weeks as maintenance therapy. Response was assessed by using immune-related response criteria and modified WHO criteria. The primary end point was immune-related progression-free survival (irPFS). Other end points were progression-free survival (PFS), best overall response rate (BORR), immune-related BORR (irBORR), overall survival (OS), and safety.The study met its primary end point of improved irPFS for phased ipilimumab versus the control (hazard ratio [HR], 0.72; P = .05), but not for concurrent ipilimumab (HR, 0.81; P = .13). Phased ipilimumab also improved PFS according to modified WHO criteria (HR, 0.69; P = .02). Phased ipilimumab, concurrent ipilimumab, and control treatments were associated with a median irPFS of 5.7, 5.5, and 4.6 months, respectively, a median PFS of 5.1, 4.1, and 4.2 months, respectively, an irBORR of 32%, 21% and 18%, respectively, a BORR of 32%, 21% and 14%, respectively, and a median OS of 12.2, 9.7, and 8.3 months. Overall rates of grade 3 and 4 immune-related AEs were 15%, 20%, and 6% for phased ipilimumab, concurrent ipilimumab, and the control, respectively. Two patients (concurrent, one patient; control, one patient) died from treatment-related toxicity.Phased ipilimumab plus paclitaxel and carboplatin improved irPFS and PFS, which supports additional investigation of ipilimumab in NSCLC.
View details for DOI 10.1200/JCO.2011.38.4032
View details for Web of Science ID 000305159200009
View details for PubMedID 22547592
First-line treatment of EGFR-mutant non-small-cell lung cancer: the role of erlotinib and other tyrosine kinase inhibitors.
Biologics : targets & therapy
2012; 6: 337-345
Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) were initially established as second- or third-line treatment of advanced non-small-cell lung cancer (NSCLC). Subsequent studies, including IPASS, OPTIMAL, and EURTAC, have demonstrated that these TKIs are effective first-line therapeutic options in patients with tumors harboring activating mutations in the EGFR gene. The TKIs are better tolerated than conventional chemotherapy, with frequent yet mild side effects such as rash and diarrhea, and rarely interstitial lung disease. Because most patients on TKIs develop resistance due to a variety of mechanisms, the use of TKIs in the acquired-resistance setting and in the setting of earlier-staged cancers is being extensively studied. Here we review the major trials leading to the established use of EGFR TKIs in NSCLC, followed by discussion of recently completed and ongoing trials using the next-generation EGFR inhibitor afatinib.
View details for DOI 10.2147/BTT.S26558
View details for PubMedID 23055691
Current Management of Small Cell Lung Cancer
CLINICS IN CHEST MEDICINE
2011; 32 (4): 853-?
Confined to one side of the chest, limited stage small cell lung cancer is treated with a combination of chemotherapy and radiotherapy, yet has a long-term survival rate of only 15%. Extensive stage disease has initial response rates to chemotherapy exceeding 70%. However, the disease almost invariably progresses and becomes fatal. Many recent clinical trials have failed to show superiority of newer chemotherapeutics or targeted therapies compared with the standard chemotherapy backbone of platinum plus etoposide. Numerous promising targeted therapies and other agents are still in development.
View details for DOI 10.1016/j.ccm.2011.07.002
View details for Web of Science ID 000297822700017
View details for PubMedID 22054891
- Targeting FGFR, Ephrins, Mer, MET, and PDGFR-alpha in Non-small Cell Lung Cancer JOURNAL OF THORACIC ONCOLOGY 2011; 6 (11): S1797-S1798
One Allele's Loss Is Another's Gain: Alterations of NKX2-8 in Non-Small Cell Lung Cancer
CLINICAL CANCER RESEARCH
2011; 17 (4): 638-639
Large-scale genetic changes such as loss or gain of chromosomes are important drivers of solid tumor carcinogenesis. Recent technological advances in genomic profiling have allowed quantitative detection of gene copy numbers, leading to identification of the 14q13.3 gene locus as functionally important in non-small cell lung cancers.
View details for DOI 10.1158/1078-0432.CCR-10-3081
View details for Web of Science ID 000287913200002
View details for PubMedID 21163872
The SATURN trial: the value of maintenance erlotinib in patients with non-small-cell lung cancer
2010; 6 (12): 1827-1832
The first-line treatment of advanced non-small-cell lung cancer (NSCLC) generally consists of a maximum of six cycles of platinum-based doublet chemotherapy followed by surveillance for disease progression. Recently, the strategy of starting second-line treatment immediately following the completion of chemotherapy, known as 'maintenance' chemotherapy, has been investigated. The use of maintenance pemetrexed improves both progression-free and overall survival, while the use of maintenance docetaxel did not significantly improve overall survival. The Sequential Tarceva in Unresectable NSCLC (SATURN) study investigated the use of maintenance erlotinib following the completion of first-line chemotherapy. It demonstrated a significant improvement in overall survival from 11.1 months in the placebo group to 12.3 months in patients receiving maintenance erlotinib, with the important caveat that only 21% of patients in the placebo group ever received erlotinib. A subset of patients whose tumors had EGF receptor mutations had a higher magnitude of benefit from maintenance treatment. Therefore, maintenance erlotinib should be considered in the treatment of patients with NSCLC.
View details for DOI 10.2217/FON.10.156
View details for Web of Science ID 000297100400007
View details for PubMedID 21142856
Cetuximab monotherapy in patients with advanced non-small cell lung cancer after prior epidermal growth factor receptor tyrosine kinase inhibitor therapy.
Journal of thoracic oncology
2010; 5 (11): 1855-1858
Therapeutic agents directed against the epidermal growth factor receptor (EGFR) signaling pathway have been effective in the treatment of non-small cell lung cancer (NSCLC). Cetuximab is a monoclonal antibody against the EGFR receptor with antitumor activity in NSCLC. This study evaluated the efficacy of cetuximab monotherapy after prior treatment with an oral EGFR tyrosine kinase inhibitor (TKI).Eligible patients had stage IIIB, IV, or recurrent NSCLC with progression on the oral EGFR TKIs gefitinib or erlotinib. Cetuximab was administered intravenously at 400 mg/m on day 1 and then 250 mg/m weekly until disease progression or unacceptable toxicity. The primary end point was response rate.Eighteen patients were enrolled. Patients were heavily pretreated with chemotherapy and TKIs (average number of treatments = 4.2). The response rate was 0/18 (0%), and 28% of patients had confirmed stable disease. Median progression-free survival was 1.8 months (95% confidence interval, 1.6-5.4 months), and median overall survival was 7.5 months (95% confidence interval, 2.2-19 months). Three patients harbored activating EGFR mutations, and one of them had stable disease for nearly 6 months on cetuximab. Common toxicities were mild and included fatigue, skin rash, and nausea/vomiting. Two patients developed interstitial lung disease, life threatening in one case.Cetuximab monotherapy administered after prior EGFR TKI treatment in patients with advanced NSCLC does not yield clinical responses.
View details for DOI 10.1097/JTO.0b013e3181f0bee0
View details for PubMedID 20975380
AMG-386, a selective angiopoietin-1/-2-neutralizing peptibody for the potential treatment of cancer
CURRENT OPINION IN MOLECULAR THERAPEUTICS
2010; 12 (4): 487-495
The VEGF/VEGFR and angiopoietin/Tie-2 signaling pathways are important in the process of vascular endothelial growth (angiogenesis) and in the maintenance of tumor-associated blood vessels. While there are several agents targeting the VEGF/VEGFR signaling pathway, there are none available that target the angiopoietin/Tie-2 signaling pathway. The first such agent to reach clinical trials is AMG-386 (2xCon4C), being developed by Amgen Inc and licensed in Japan to Takeda Bio Development Center Ltd. AMG-386 is an anti-angiopoietin peptibody comprising a peptide with angiopoietin-binding properties that is fused to the Fc (crystallizable fragment) region of an antibody and inhibits the interaction between the ligands angiopoietin-1 and angiopoietin-2 with the Tie-2 receptor. AMG-386 significantly inhibited the growth of tumors in a variety of mouse xenograft models. In phase I trials of AMG-386 as a monotherapy or in combination with chemotherapy in patients with advanced solid tumors, AMG-386 demonstrated only mild toxicities, and one complete response and several partial responses were achieved in patients. Phase II trials of AMG-386 in combination with chemotherapy were ongoing in a variety of solid tumors, including breast, ovarian, colorectal, gastric and renal cell cancers. If safe and effective, AMG-386 could be an exciting addition to other antiangiogenic therapies in solid tumors.
View details for Web of Science ID 000280507000013
View details for PubMedID 20677100
Exciting New Targets in Lung Cancer Therapy: ALK, IGF-1R, HDAC, and Hh
CURRENT TREATMENT OPTIONS IN ONCOLOGY
2010; 11 (1-2): 36-44
The anaplastic lymphoma kinase (ALK) inhibitor crizotinib will become an integral addition to the treatment of patients with non-small cell lung cancer (NSCLC) harboring genetic ALK translocations. The insulin-like growth factor receptor (IGF-1R) monoclonal antibody figitumumab, while initially promising, appears to increase toxicity and death in combination with chemotherapy in the treatment of patients with NSCLC of squamous histology; therefore, clinical development of this class of agents will need to proceed with caution. The histone deacetylation (HDAC) inhibitor vorinostat did not demonstrate an improvement in overall survival (OS) compared with placebo in a large randomized trial, but other agents in this class may have greater selectivity and efficacy. Inhibitors of the hedgehog (Hh) signaling pathways have some early clinical promise in both NSCLC and small cell lung cancer (SCLC), and larger studies using these agents are eagerly anticipated.
View details for DOI 10.1007/s11864-010-0120-6
View details for Web of Science ID 000281247200004
View details for PubMedID 20676809
- Targeted therapies: optimal first-line therapy for NSCLC with EGFR mutations. Nature reviews. Clinical oncology 2010; 7 (2): 71-72
First-line use of EGFR tyrosine kinase inhibitors in patients with NSCLC containing EGFR mutations.
Clinical advances in hematology & oncology : H&O
2010; 8 (2): 119-126
While the small molecule epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors erlotinib and gefitinib have modest clinical benefit in unselected patients with non-small cell lung cancer after platinum-based chemotherapy, an emerging and potentially more elegant strategy is to move these agents to the frontline setting for select patients. Those with somatic mutations in EGFR respond dramatically to EGFR inhibitors, and mounting evidence from recent clinical trials, particularly the Iressa Pan-Asia Study (IPASS) trial, confirms superior response rates, progression-free survival, and tolerability with this targeted therapy compared with conventional chemotherapy. Here, we review the studies supporting the use of EGFR tyrosine kinase inhibitors in the frontline setting in patients with EGFR mutations.
View details for PubMedID 20386533
Induction of FucT-VII by the Ras/MAP kinase cascade in Jurkat T cells
2003; 102 (5): 1771-1778
Induction of the alpha1,3-fucosyltransferase FucT-VII in T lymphocytes is crucial for selectin ligand formation, but the signaling and transcriptional pathways that govern FucT-VII expression are unknown. Here, using a novel, highly phorbol myristate acetate (PMA)-responsive variant of the Jurkat T-cell line, we identify Ras and downstream mitogen-activated protein (MAP) kinase pathways as essential mediators of FucT-VII gene expression. PMA induced FucT-VII in only a subset of treated cells, similar to expression of FucT-VII in normal activated CD4 T cells. Introduction of constitutively active Ras or Raf by recombinant retroviruses induced FucT-VII expression only in that subset of cells expressing the highest levels of Ras, suggesting that induction of FucT-VII required a critical threshhold of Ras signaling. Both PMA treatment and introduction of active Ras led to rolling on E-selectin. Pharmacologic inhibition studies confirmed the involvement of the classic Ras-Raf-MEK-extracellular signal-regulated kinase (Ras-Raf-MEK-ERK) pathway in FucT-VII induction by PMA, Ras, and Raf. These studies also revealed a second, Ras-induced, Raf-1-independent pathway that participated in induction of FucT-VII. Strong activation of Ras represents a major pathway for induction of FucT-VII gene expression in T cells.
View details for DOI 10.1182/blood-2002-11-3551
View details for Web of Science ID 000184945200042
View details for PubMedID 12738675
A constitutively active NFATc1 mutant induces a transformed phenotype in 3T3-L1 fibroblasts
JOURNAL OF BIOLOGICAL CHEMISTRY
2003; 278 (19): 17246-17254
The calcineurin/nuclear factor of activated T cells (NFAT) signaling pathway is best known for its role in T lymphocyte activation. However, it has become increasingly apparent that this signaling pathway is also involved in the regulation of cell growth and development in a wide variety of different tissues and cell types. Here we have investigated the effects of sustained NFATc1 signaling on the growth and differentiation of the murine 3T3-L1 preadipocyte cell line. Remarkably, we find that expression of a constitutively active NFATc1 mutant (caNFATc1) in these immortalized cells inhibits their differentiation into mature adipocytes and causes them to adopt a transformed cell phenotype, including loss of contact-mediated growth inhibition, reduced serum growth requirements, protection from growth factor withdrawal-induced apoptosis, and formation of colonies in semisolid media. Furthermore, we find that caNFATc1-expressing cells acquire growth factor autonomy and are able to proliferate even in the complete absence of serum. We provide evidence that this growth factor independence is caused by the NFATc1-dependent production of a soluble heat-labile autocrine factor that is capable of promoting the growth and survival of wild type 3T3-L1 cells as well as potently inhibiting their differentiation into mature adipocytes. Finally, we demonstrate that cells expressing caNFATc1 form tumors in nude mice. Taken together, these results indicate that deregulated NFATc1 activity is able to induce the immortalized 3T3-L1 preadipocyte cell line to acquire the well established hallmarks of cellular transformation and thereby provide direct evidence for the oncogenic potential of the NFATc1 transcription factor.
View details for DOI 10.1074/jbc.M300528200
View details for Web of Science ID 000182818600107
View details for PubMedID 12598522
Calcineurin mediates the calcium-dependent inhibition of adipocyte differentiation in 3T3-L1 cells
JOURNAL OF BIOLOGICAL CHEMISTRY
2002; 277 (51): 49776-49781
Recent studies have revealed that the calcium-dependent serine/threonine phosphatase calcineurin mediates the effects of intracellular calcium in many different cell types. In this study we investigated the role of calcineurin in the regulation of adipocyte differentiation. We found that the specific calcineurin inhibitors cyclosporin A and FK506 overcame the antiadipogenic effect of calcium ionophore on the differentiation of 3T3-L1 preadipocytes. This finding suggests that calcineurin is responsible for mediating the previously documented Ca(2+)-dependent inhibition of adipogenesis. We further demonstrate that the expression of a constitutively active calcineurin mutant potently inhibits the ability of 3T3-L1 cells to undergo adipocyte differentiation by preventing expression of the proadipogenic transcription factors peroxisome proliferator-activated receptor gamma (PPARgamma) and CCAAT/enhancer-binding protein alpha (C/EBPalpha). This calcineurin-mediated block in adipocyte differentiation is rescued by ectopic expression of PPARgamma1. Finally, we demonstrate that inhibition of endogenous calcineurin activity with either FK506 or a specific calcineurin inhibitory peptide enhances differentiation of 3T3-L1 cells in response to suboptimal adipogenic stimuli, suggesting that endogenous calcineurin activity normally sets a signaling threshold that antagonizes efficient adipocyte differentiation. Collectively, these data indicate that calcineurin acts as a Ca(2+)-dependent molecular switch that negatively regulates commitment to adipocyte differentiation by preventing the expression of critical proadipogenic transcription factors.
View details for DOI 10.1074/jbc.M207913200
View details for Web of Science ID 000180028900090
View details for PubMedID 12351639
Glycogen synthase kinase-3 inhibits the DNA binding activity of NFATc
JOURNAL OF BIOLOGICAL CHEMISTRY
2001; 276 (5): 3666-3673
The NFAT family of transcription factors is required for the expression of numerous immunologically important genes and plays a pivotal role in both the initiation and coordination of the immune response. NFAT family members appear to be regulated primarily at the level of their subcellular localization. Here we show that NFATc is additionally regulated at the level of its DNA binding activity. Using gel mobility shift assays, we demonstrate that the intrinsic DNA binding activity of NFATc is negatively regulated by phosphorylation. We found that activation of calcineurin activity in cells and dephosphorylation of NFATc in vitro enhanced NFATc DNA binding activity, whereas phosphorylation of NFATc in vitro inhibited its ability to bind DNA. Through the analysis of NFATc mutants, we identified the conserved Ser-Pro repeat motifs as critical quantitative determinants of NFATc DNA binding activity. In addition, we provide several lines of evidence to suggest that the phosphorylation of the Ser-Pro repeats by glycogen synthase kinase-3 inhibits the ability of NFATc to bind DNA. Taken together, these studies afford new insights into the regulation of NFATc and underscore the potential role of glycogen synthase kinase-3 in the regulation of NFAT-dependent gene expression.
View details for Web of Science ID 000166784900089
View details for PubMedID 11063740
REGULATION OF THE GLUCOSE-H+ SYMPORTER BY METABOLITE-ACTIVATED ATP-DEPENDENT PHOSPHORYLATION OF HPR IN LACTOBACILLUS-BREVIS
JOURNAL OF BACTERIOLOGY
1994; 176 (12): 3484-3492
Lactobacillus brevis takes up glucose and the nonmetabolizable glucose analog 2-deoxyglucose (2DG), as well as lactose and the nonmetabolizable lactose analoge thiomethyl beta-galactoside (TMG), via proton symport. Our earlier studies showed that TMG, previously accumulated in L. brevis cells via the lactose:H+ symporter, rapidly effluxes from L. brevis cells or vesicles upon addition of glucose and that glucose inhibits further accumulation of TMG. This regulation was shown to be mediated by a metabolite-activated protein kinase that phosphorylase serine 46 in the HPr protein. We have now analyzed the regulation of 2DG uptake and efflux and compared it with that of TMG. Uptake of 2DG was dependent on an energy source, effectively provided by intravesicular ATP or by extravesicular arginine which provides ATP via an ATP-generating system involving the arginine deiminase pathway. 2DG uptake into these vesicles was not inhibited, and preaccumulated 2DG did not efflux from them upon electroporation of fructose 1,6-diphosphate or gluconate 6-phosphate into the vesicles. Intravesicular but not extravesicular wild-type or H15A mutant HPr of Bacillus subtilis promoted inhibition (53 and 46%, respectively) of the permease in the presence of these metabolites. Counterflow experiments indicated that inhibition of 2DG uptake is due to the partial uncoupling of proton symport from sugar transport. Intravesicular S46A mutant HPr could not promote regulation of glucose permease activity when electroporated into the vesicles with or without the phosphorylated metabolites, but the S46D mutant protein promoted regulation, even in the absence of a metabolite. The Vmax but not the Km values for both TMG and 2DG uptake were affected. Uptake of the natural, metabolizable substrates of the lactose, glucose, mannose, and ribose permeases was inhibited by wild-type HPr in the presence of fructose 1,6-diphosphate or by S46D mutant HPr. These results establish that HPr serine phosphorylation by the ATP-dependent, metabolite-activated HPr kinase regulates glucose and lactose permease activities in L. brevis and suggest that other permeases may also be subject to this mode of regulation.
View details for Web of Science ID A1994NQ76400006
View details for PubMedID 8206825