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1.
Respir Med ; 211: 107195, 2023 05.
Article in English | MEDLINE | ID: mdl-36889520

ABSTRACT

INTRODUCTION: Previous studies have shown that the population attributable risk of low forced expiratory volume in one second (FEV1) for coronary artery disease (CAD) is substantial. FEV1 can be low either because of airflow obstruction or ventilatory restriction. It is not known if low FEV1 arising from spirometric obstruction or restriction are differently associated with CAD. METHODS: We analyzed high resolution computed tomography (CT) scans acquired at full inspiration in lifetime non-smoker adults with no lung disease (controls) and those with chronic obstructive pulmonary disease enrolled in the Genetic Epidemiology of COPD (COPDGene) study. We also analyzed CT scans of adults with idiopathic pulmonary fibrosis (IPF) from a cohort of patients attending a quaternary referral clinic. Participants with IPF were matched 1:1 by FEV1 %predicted to adults with COPD and 1:1 by age to lifetime non-smokers. Coronary artery calcium (CAC), a surrogate for CAD, was measured by visual quantification on CT using the Weston score. Significant CAC was defined as Weston score ≥7. Multivariable regression models were used to test the association of the presence of COPD or IPF with CAC, with adjustment for age, sex, body-mass-index, smoking status, hypertension, diabetes mellitus, and hyperlipidemia. RESULTS: We included 732 subjects in the study; 244 with IPF, 244 with COPD, and 244 lifetime non-smokers. The mean (SD) age was 72.6 (8.1), 62.6 (7.4), and 67.3 (6.6) years, and median (IQR) CAC was 6 (6), 2 (6), and 1 (4), in IPF, COPD, and non-smokers, respectively. On multivariable analyses, the presence of COPD was associated with higher CAC compared to non-smokers (adjusted regression coefficient, ß = 1.10 ± SE0.51; P = 0.031). The presence of IPF was also associated with higher CAC compared to non-smokers (ß = 03.43 ± SE0.41; P < 0.001). The adjusted odds ratio for having significant CAC was 1.3, 95% CI 0.6 to 2.8; P = 0.53 in COPD and 5.6, 95% CI 2.9 to 10.9; P < 0.001 in IPF, compared to non-smokers. In sex stratified analyses, these associations were mainly noted in women. CONCLUSION: Adults with IPF displayed higher coronary artery calcium than those with COPD after accounting for age and lung function impairment.


Subject(s)
Coronary Artery Disease , Idiopathic Pulmonary Fibrosis , Pulmonary Disease, Chronic Obstructive , Adult , Humans , Female , Coronary Artery Disease/complications , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/epidemiology , Calcium , Pulmonary Disease, Chronic Obstructive/complications , Pulmonary Disease, Chronic Obstructive/diagnostic imaging , Pulmonary Disease, Chronic Obstructive/epidemiology , Lung , Idiopathic Pulmonary Fibrosis/complications , Idiopathic Pulmonary Fibrosis/diagnostic imaging , Idiopathic Pulmonary Fibrosis/epidemiology , Forced Expiratory Volume
2.
Open Access Emerg Med ; 15: 15-20, 2023.
Article in English | MEDLINE | ID: mdl-36660272

ABSTRACT

Background: Beginning January 26th, 2022, the National Board of Medical Examiners transitioned scoring of the United States Medical Licensing Examination (USMLE) Step 1 from a 3-digit score to pass/fail. In the past, the Step 1 score has been weighted heavily by program directors (PDs) as one of the most important metrics when assessing medical student's competitiveness. Objective: The objective of this study was to evaluate the perceptions of emergency medicine (EM) PDs on the transition to a pass/fail USMLE Step 1 exam, and to elicit the opinions of EM PDs on the USMLE examinations' ability to predict resident performance. Methods: A survey consisting of ranking and multiple-choice questions was sent to EM PDs. The multiple-choice questions were asked to determine EM PDs level of confidence in the ability of Step 1 and Step 2 Clinical Knowledge (CK) to predict a student's ability to succeed in residency. The ranking questions focused on assessing each program's current resident selection practices in comparison to expected selection criteria changes following a transition to pass/fail Step 1. R studio and MATLAB were used for statistical analysis, and a P value <0.05 was considered significant. Results: The survey was completed by 57 (20.21%) EM PDs. When asked if Step 1 and Step 2 CK are accurate predictors of a resident's ability to perform clinically within EM, only 10.5% of PDs answered 'yes' to Step 1 being predictive, compared to 31.6% for Step 2 CK. Regarding selection criteria, the top quartile of attributes (standardized letters of evaluation [1st], away rotations [2nd], clerkship grades [3rd] and Step 2 CK score [4th]) remained the same following the transition. Conclusion: Our results indicate that the top quartile of attributes might remain the same, despite most PDs agreeing that Step 2 CK is a better predictor of a resident's performance.

3.
S D Med ; 75(7): 324-327, 2022 Jul.
Article in English | MEDLINE | ID: mdl-36542573

ABSTRACT

Uterine rupture is a potentially life-threatening complication that is typically seen in pregnant females who have undergone prior uterine surgeries such as cesarean sections. This usually occurs when the uterine myometrium is weakened and thus is more prone to stress during labor. In an unscarred uterus, the incidence of uterine rupture is lower. Risk factors in the unscarred uterus include trauma, obstructed labor, high parity, placental abnormalities, operative deliveries, and imprudent use of uterotonic medications. This case report describes a situation in which uterine rupture occurred in the absence of the common risk factors. With prompt recognition of clinical signs, quick assembly of a team, and emergent interventions, this patient and her infant survived. The goal of this report is to educate clinicians on the occurrence of uterine rupture in an unscarred uterus and how to recognize and manage this complication.


Subject(s)
Labor, Obstetric , Uterine Rupture , Humans , Pregnancy , Female , Uterine Rupture/diagnosis , Uterine Rupture/etiology , Uterine Rupture/surgery , Placenta , Uterus , Parity
5.
Clin Transl Immunology ; 11(2): e1373, 2022.
Article in English | MEDLINE | ID: mdl-35136603

ABSTRACT

OBJECTIVES: Autologous chimeric antigen receptor (CAR) αß T-cell therapies have demonstrated remarkable antitumor efficacy in patients with haematological malignancies; however, not all eligible cancer patients receive clinical benefit. Emerging strategies to improve patient access and clinical responses include using premanufactured products from healthy donors and alternative cytotoxic effectors possessing intrinsic tumoricidal activity as sources of CAR cell therapies. γδ T cells, which combine innate and adaptive mechanisms to recognise and kill malignant cells, are an attractive candidate platform for allogeneic CAR T-cell therapy. Here, we evaluated the manufacturability and functionality of allogeneic peripheral blood-derived CAR+ Vδ1 γδ T cells expressing a second-generation CAR targeting the B-cell-restricted CD20 antigen. METHODS: Donor-derived Vδ1 γδ T cells from peripheral blood were ex vivo-activated, expanded and engineered to express a novel anti-CD20 CAR. In vitro and in vivo assays were used to evaluate CAR-dependent and CAR-independent antitumor activities of CD20 CAR+ Vδ1 γδ T cells against B-cell tumors. RESULTS: Anti-CD20 CAR+ Vδ1 γδ T cells exhibited innate and adaptive antitumor activities, such as in vitro tumor cell killing and proinflammatory cytokine production, in addition to in vivo tumor growth inhibition of B-cell lymphoma xenografts in immunodeficient mice. Furthermore, CD20 CAR+ Vδ1 γδ T cells did not induce xenogeneic graft-versus-host disease in immunodeficient mice. CONCLUSION: These preclinical data support the clinical evaluation of ADI-001, an allogeneic CD20 CAR+ Vδ1 γδ T cell, and a phase 1 study has been initiated in patients with B-cell malignancies (NCT04735471).

6.
Sci Rep ; 11(1): 14397, 2021 07 13.
Article in English | MEDLINE | ID: mdl-34257348

ABSTRACT

T-cell-redirecting bispecific antibodies have emerged as a new class of therapeutic agents designed to simultaneously bind to T cells via CD3 and to tumor cells via tumor-cell-specific antigens (TSA), inducing T-cell-mediated killing of tumor cells. The promising preclinical and clinical efficacy of TSAxCD3 antibodies is often accompanied by toxicities such as cytokine release syndrome due to T-cell activation. How the efficacy and toxicity profile of the TSAxCD3 bispecific antibodies depends on the binding affinity to CD3 remains unclear. Here, we evaluate bispecific antibodies that were engineered to have a range of CD3 affinities, while retaining the same binding affinity for the selected tumor antigen. These agents were tested for their ability to kill tumor cells in vitro, and their biodistribution, serum half-life, and anti-tumor activity in vivo. Remarkably, by altering the binding affinity for CD3 alone, we can generate bispecific antibodies that maintain potent killing of TSA + tumor cells but display differential patterns of cytokine release, pharmacokinetics, and biodistribution. Therefore, tuning CD3 affinity is a promising method to improve the therapeutic index of T-cell-engaging bispecific antibodies.


Subject(s)
Antibodies, Bispecific , CD3 Complex , Cytokines , Cytokines/metabolism , Lymphocyte Activation , Tissue Distribution
7.
Blood Adv ; 5(5): 1291-1304, 2021 03 09.
Article in English | MEDLINE | ID: mdl-33651100

ABSTRACT

CD3-engaging bispecific antibodies (bsAbs) and chimeric antigen receptor (CAR) T cells are potent therapeutic approaches for redirecting patient T cells to recognize and kill tumors. Here we describe a fully human bsAb (REGN5458) that binds to B-cell maturation antigen (BCMA) and CD3, and compare its antitumor activities vs those of anti-BCMA CAR T cells to identify differences in efficacy and mechanism of action. In vitro, BCMAxCD3 bsAb efficiently induced polyclonal T-cell killing of primary human plasma cells and multiple myeloma (MM) cell lines expressing a range of BCMA cell surface densities. In vivo, BCMAxCD3 bsAb suppressed the growth of human MM tumors in murine xenogeneic models and showed potent combinatorial efficacy with programmed cell death protein 1 blockade. BCMAxCD3 bsAb administration to cynomolgus monkeys was well tolerated, resulting in the depletion of BCMA+ cells and mild inflammatory responses characterized by transient increases in C-reactive protein and serum cytokines. The antitumor efficacy of BCMAxCD3 bsAb was compared with BCMA-specific CAR T cells containing a BCMA-binding single-chain variable fragment derived from REGN5458. Both BCMAxCD3 bsAb and anti-BCMA CAR T cells showed similar targeted cytotoxicity of MM cell lines and primary MM cells in vitro. In head-to-head in vivo studies, BCMAxCD3 bsAb rapidly cleared established systemic MM tumors, whereas CAR T cells cleared tumors with slower kinetics. Thus, using the same BCMA-binding domain, these results suggest that BCMAxCD3 bsAb rapidly exerts its therapeutic effects by engaging T cells already in place at the tumor site, whereas anti-BCMA CAR T cells require time to traffic to the tumor site, activate, and numerically expand before exerting antitumor effects.


Subject(s)
Antibodies, Bispecific , Multiple Myeloma , Animals , Antibodies, Bispecific/therapeutic use , B-Cell Maturation Antigen , Humans , Immunotherapy, Adoptive , Mice , Multiple Myeloma/drug therapy , T-Lymphocytes
8.
JAMA Ophthalmol ; 135(6): 570-575, 2017 06 01.
Article in English | MEDLINE | ID: mdl-28448669

ABSTRACT

Importance: Age-related macular degeneration (AMD) is the leading cause of irreversible vision impairment in older adults in the United States, yet little is known about whether AMD is appropriately diagnosed in primary eye care. Objectives: To examine the prevalence of eyes with AMD in patients seen in primary eye care clinics who purportedly have normal macular health per their medical record and the association of AMD with patient and physician characteristics. Design, Setting, and Participants: In this cross-sectional study of primary eye care practices in Birmingham, Alabama, 644 persons 60 years or older with normal macular health per medical record based on their most recent dilated comprehensive eye examination by a primary eye care ophthalmologist or optometrist were enrolled from May 1, 2009, through December 31, 2011. Data analysis was performed from May 1, 2016, through December 20, 2016. Main Outcomes and Measures: Presence of AMD as defined by the Clinical Age-Related Maculopathy Staging system based on color fundus photography and a masked grader. Types of AMD-associated lesions were noted. Patient health and physician characteristics were collected. Results: The sample consisted of 1288 eyes from 644 participants (231 [35.9%] male and 413 [64.1%] female; mean [SD] age, 69.4 [6.1] years; 611 white [94.9%]) seen by 31 primary eye care ophthalmologists or optometrists. A total of 968 eyes (75.2%) had no AMD, in agreement with their medical record; 320 (24.8%) had AMD despite no diagnosis of AMD in the medical record. Among eyes with undiagnosed AMD, 32 (10.0%) had hyperpigmentation, 43 (13.4%) had hypopigmentation, 249 (77.8%) had small drusen, 250 (78.1%) had intermediate drusen, and 96 (30.0%) had large drusen. Undiagnosed AMD was associated with older patient age (odds ratio [OR], 1.06; 95% CI, 1.04-1.09; P < .001), male sex (age-adjusted OR, 1.39; 95% CI, 1.02-1.91; P = .04), and less than a high school education (age-adjusted OR, 2.40; 95% CI, 1.03-5.62; P = .04). Prevalence of undiagnosed AMD was not different for ophthalmologists and optometrists (age adjusted OR, 0.99; 95% CI, 0.71-1.36; P = .94). Conclusions and Relevance: Approximately 25.0% of eyes deemed to be normal based on dilated eye examination by primary eye care physicians had macular characteristics that indicated AMD revealed by fundus photography and trained raters. A total of 30.0% of eyes with undiagnosed AMD had AMD with large drusen that would have been treatable with nutritional supplements had it been diagnosed. Improved AMD detection strategies may be needed in primary eye care as more effective treatment strategies for early AMD become available in the coming years.


Subject(s)
Diagnostic Errors/statistics & numerical data , Diagnostic Techniques, Ophthalmological , Macular Degeneration/epidemiology , Primary Health Care/statistics & numerical data , Aged , Alabama/epidemiology , Cross-Sectional Studies , Female , Humans , Macular Degeneration/diagnosis , Male , Middle Aged , Odds Ratio , Prevalence , Prospective Studies , Tomography, Optical Coherence
9.
Proc Natl Acad Sci U S A ; 113(1): 182-7, 2016 Jan 05.
Article in English | MEDLINE | ID: mdl-26677873

ABSTRACT

Macroautophagy is a key stress-response pathway that can suppress or promote tumorigenesis depending on the cellular context. Notably, Kirsten rat sarcoma (KRAS)-driven tumors have been reported to rely on macroautophagy for growth and survival, suggesting a potential therapeutic approach of using autophagy inhibitors based on genetic stratification. In this study, we evaluated whether KRAS mutation status can predict the efficacy to macroautophagy inhibition. By profiling 47 cell lines with pharmacological and genetic loss-of-function tools, we were unable to confirm that KRAS-driven tumor lines require macroautophagy for growth. Deletion of autophagy-related 7 (ATG7) by genome editing completely blocked macroautophagy in several tumor lines with oncogenic mutations in KRAS but did not inhibit cell proliferation in vitro or tumorigenesis in vivo. Furthermore, ATG7 knockout did not sensitize cells to irradiation or to several anticancer agents tested. Interestingly, ATG7-deficient and -proficient cells were equally sensitive to the antiproliferative effect of chloroquine, a lysosomotropic agent often used as a pharmacological tool to evaluate the response to macroautophagy inhibition. Moreover, both cell types manifested synergistic growth inhibition when treated with chloroquine plus the tyrosine kinase inhibitors erlotinib or sunitinib, suggesting that the antiproliferative effects of chloroquine are independent of its suppressive actions on autophagy.


Subject(s)
Antineoplastic Agents/pharmacology , Autophagy/drug effects , Cell Transformation, Neoplastic/drug effects , Chloroquine/pharmacology , Drug Resistance, Neoplasm/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Autophagy/genetics , Autophagy-Related Protein 7 , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/pathology , Erlotinib Hydrochloride/pharmacology , Gene Knockout Techniques , Humans , Indoles/pharmacology , Mutation , Protein Kinase Inhibitors/pharmacology , Pyrroles/pharmacology , Radiation Tolerance/genetics , Sunitinib , Ubiquitin-Activating Enzymes/genetics
10.
Nat Commun ; 5: 4900, 2014 Sep 25.
Article in English | MEDLINE | ID: mdl-25254627

ABSTRACT

The non-essential amino acid, glutamine, exerts pleiotropic effects on cell metabolism, signalling and stress resistance. Here we demonstrate that short-term glutamine restriction triggers an endoplasmic reticulum (ER) stress response that leads to production of the pro-inflammatory chemokine, interleukin-8 (IL-8). Glutamine deprivation-induced ER stress triggers colocalization of autophagosomes, lysosomes and the Golgi into a subcellular structure whose integrity is essential for IL-8 secretion. The stimulatory effect of glutamine restriction on IL-8 production is attributable to depletion of tricarboxylic acid cycle intermediates. The protein kinase, mTOR, is also colocalized with the lysosomal membrane clusters induced by glutamine deprivation, and inhibition of mTORC1 activity abolishes both endomembrane reorganization and IL-8 secretion. Activated mTORC1 elicits IL8 gene expression via the activation of an IRE1-JNK signalling cascade. Treatment of cells with a glutaminase inhibitor phenocopies glutamine restriction, suggesting that these results will be relevant to the clinical development of glutamine metabolism inhibitors as anticancer agents.


Subject(s)
Interleukin-8/metabolism , MAP Kinase Kinase 4/metabolism , TOR Serine-Threonine Kinases/metabolism , Cell Line, Tumor , Citric Acid Cycle , Endoplasmic Reticulum Stress , Glutamine , Humans , Lysosomes/metabolism , MAP Kinase Kinase 4/genetics , Mechanistic Target of Rapamycin Complex 1 , Multiprotein Complexes/genetics , Multiprotein Complexes/metabolism , TOR Serine-Threonine Kinases/genetics
11.
Annu Rev Pharmacol Toxicol ; 53: 89-106, 2013.
Article in English | MEDLINE | ID: mdl-23294306

ABSTRACT

A fundamental imperative for mammalian cells is to coordinate cell metabolism and growth with environmentally induced stress. This review focuses on three highly integrated networks-the phosphoinositide 3-kinase (PI3K) signaling cascade, intermediate metabolism, and autophagy-that work together to maintain cellular homeostasis under basal conditions and to drive cell-mass accumulation and cell cycle progression in the presence of appropriate mitogenic stimuli. Dysfunction within any one of these networks results in compensatory responses from the other networks. These responses underpin several pathologies associated with major human diseases such as cancer. We discuss the PI3K, metabolism, and autophagy networks and provide selected insights into internetwork cross-talk mechanisms. In recognition of the extensive interactions observed in both healthy and diseased cells, we propose that the three networks be merged into a "metabolism-signaling supernetwork." A detailed understanding of this supernetwork will facilitate the development of novel therapies for cancer and other complex diseases.


Subject(s)
Autophagy/physiology , Phosphatidylinositol 3-Kinases/metabolism , Animals , Homeostasis , Humans , Signal Transduction
12.
PLoS One ; 7(7): e41831, 2012.
Article in English | MEDLINE | ID: mdl-22848625

ABSTRACT

mTOR inhibitors are used clinically to treat renal cancer but are not curative. Here we show that autophagy is a resistance mechanism of human renal cell carcinoma (RCC) cell lines to mTOR inhibitors. RCC cell lines have high basal autophagy that is required for survival to mTOR inhibition. In RCC4 cells, inhibition of mTOR with CCI-779 stimulates autophagy and eliminates RIP kinases (RIPKs) and this is blocked by autophagy inhibition, which induces RIPK- and ROS-dependent necroptosis in vitro and suppresses xenograft growth. Autophagy of mitochondria is required for cell survival since mTOR inhibition turns off Nrf2 antioxidant defense. Thus, coordinate mTOR and autophagy inhibition leads to an imbalance between ROS production and defense, causing necroptosis that may enhance cancer treatment efficacy.


Subject(s)
Antineoplastic Agents/pharmacology , Autophagy/drug effects , Protein Kinase Inhibitors/pharmacology , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , TOR Serine-Threonine Kinases/antagonists & inhibitors , Active Transport, Cell Nucleus/drug effects , Animals , Antioxidants/metabolism , Basal Metabolism/drug effects , Carcinoma, Renal Cell/pathology , Cell Line, Tumor , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Cell Survival/drug effects , Chloroquine/pharmacology , Humans , Mice , Mitochondria/drug effects , Mitochondria/metabolism , NF-E2-Related Factor 2/metabolism , Necrosis , Oxidation-Reduction/drug effects , Xenograft Model Antitumor Assays
13.
Prostate ; 72(12): 1374-81, 2012 Sep 01.
Article in English | MEDLINE | ID: mdl-22241682

ABSTRACT

PURPOSE: Targeting multiple anti-apoptotic proteins is now possible with the small molecule BH3 domain mimetics such as ABT-737. Given recent studies demonstrating that autophagy is a resistance mechanism to multiple therapeutic agents in the setting of apoptotic inhibition, we hypothesized that hydroxychloroquine (HCQ), an anti-malarial drug that inhibits autophagy, will increase cytotoxicity of ABT-737. EXPERIMENTAL DESIGN: Cytotoxicity of ABT-737 and HCQ was assessed in vitro in PC-3 and LNCaP cells, and in vivo in a xenograft mouse model. The role of autophagy as a resistance mechanism was assessed by siRNA knockdown of the essential autophagy gene beclin1. ROS was measured by flow cytometry, and mitophagy assessed by the mCherry-Parkin reporter. RESULTS: Induction of autophagy by ABT-737 was a mechanism of resistance in prostate cancer cell lines. Therapeutic inhibition of autophagy with HCQ increased cytotoxicity of ABT-737 both in vitro and in vivo. ABT-737 induced LC-3 and decreased p62 expression by immunoblot in cell lines and by immunohistochemistry in tumors in vivo. Assessment of ROS and mitochondria demonstrated that ROS production by ABT-737 and HCQ was a mechanism of cytotoxicity. CONCLUSIONS: We demonstrated that autophagy inhibition with HCQ enhances ABT-737 cytotoxicity in vitro and in vivo, that LC-3 and p62 represent assessable markers in human tissue for future clinical trials, and that ROS induction is a mechanism of cytotoxicity. These results support a new paradigm of dual targeting of apoptosis and autophagy in future clinical studies.


Subject(s)
Apoptosis/drug effects , Autophagy/drug effects , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/pathology , Animals , Apoptosis/physiology , Autophagy/physiology , Biphenyl Compounds/administration & dosage , Cell Line, Tumor , Drug Therapy, Combination , Humans , Hydroxychloroquine/administration & dosage , Male , Mice , Mice, Nude , Nitrophenols/administration & dosage , Piperazines/administration & dosage , Prostatic Neoplasms/metabolism , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Proto-Oncogene Proteins c-bcl-2/metabolism , Sulfonamides/administration & dosage , Treatment Outcome , Xenograft Model Antitumor Assays/methods
14.
Prostate ; 70(13): 1388-94, 2010 Sep 15.
Article in English | MEDLINE | ID: mdl-20687211

ABSTRACT

BACKGROUND: A profound difference between cancer and normal tissues is the preferential utilization of glycolysis by cancer cells. To translate this paradigm in the clinic, we completed a phase I study of 2-deoxyglucose (2DG), and assessed 2DG uptake with fluorodeoxyglucose (FDG) positron emission tomography (PET) and the autophagy substrate p62 as a marker of 2DG resistance. METHODS: Patients received 2DG orally on days 1-14 of a 21-day cycle in cohorts of three in a dose-escalating manner. Correlative assessments included PET scans at baseline and day 2 and p62 protein in peripheral blood mononuclear cells as a potential marker of 2DG resistance. RESULTS: The dose of 45 mg/kg was defined as the recommended phase II dose, secondary to dose-limiting toxicity of grade 3 asymptomatic QTc prolongation at a dose of 60 mg/kg. PK evaluation of 2DG revealed linear pharmacokinetics with C(max) 45 microg/ml (277 microM), 73.7 microg/ml (449 microM), and 122 microg/ml (744 microM) in dose levels 30, 45, and 60 mg/kg, respectively. Five of eight patients assessed with FDG-PET scanning demonstrated decreased FDG uptake by day 2 of therapy, suggesting competition of 2DG with FDG. Five of six patients assessed for p62 had a decrease in p62 at 24 hr. CONCLUSIONS: These data support the safety of 2DG, defined 2DG PK, demonstrated the effect of 2DG on FDG-PET imaging, and demonstrated the feasibility of assessment of p62 as an autophagic resistance marker. These data support future studies of 2DG alone or in combination with approaches to abrogate autophagy.


Subject(s)
Deoxyglucose/therapeutic use , Prostatic Neoplasms/drug therapy , Adult , Aged , Aged, 80 and over , Area Under Curve , Deoxyglucose/administration & dosage , Deoxyglucose/pharmacokinetics , Drug Administration Schedule , Female , Humans , Male , Middle Aged , Patient Selection , Positron-Emission Tomography , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/metabolism , Uterine Cervical Neoplasms/diagnostic imaging , Uterine Cervical Neoplasms/drug therapy , Uterine Cervical Neoplasms/metabolism
15.
Mol Cancer Res ; 7(9): 1487-96, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19737977

ABSTRACT

Apoptosis resistance is a hallmark of cancer linked to disease progression and treatment resistance, which has led to the development of anticancer therapeutics that restore apoptotic function. Antiapoptotic Bcl-2 is frequently overexpressed in refractory prostate cancer and increased following standard hormonal therapy and chemotherapy; however, the rationally designed Bcl-2 antagonist, ABT-737, has not shown single agent apoptosis-promoting activity against human prostate cancer cell lines. This is likely due to the coordinate expression of antiapoptotic, Bcl-2-related Mcl-1 that is not targeted by ABT-737. We developed a mouse model for prostate cancer in which apoptosis resistance and tumorigenesis were conferred by Bcl-2 expression. Combining ABT-737 with agents that target Mcl-1 sensitized prostate cancer cell lines with an apoptotic block to cell death in vitro. In mice in vivo, ABT-737 showed single agent efficacy in prostate tumor allografts in which tumor cells are under hypoxic stress. In human prostate cancer tissue, examined using a novel tumor explant system designated Tumor Tissue Assessment for Response to Chemotherapy, combination chemotherapy promoted efficient apoptosis. Thus, rational targeting of both the Bcl-2 and Mcl-1 mechanisms of apoptosis resistance may be therapeutically advantageous for advanced prostate cancer.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Apoptosis/drug effects , Biphenyl Compounds/pharmacology , Nitrophenols/pharmacology , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/pathology , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Sulfonamides/pharmacology , Animals , Apoptosis/physiology , Biphenyl Compounds/administration & dosage , Cisplatin/administration & dosage , Cisplatin/pharmacology , Drug Synergism , Humans , Immunohistochemistry , Male , Mice , Mice, Inbred C57BL , Mice, Nude , Myeloid Cell Leukemia Sequence 1 Protein , Nitrophenols/administration & dosage , Paclitaxel/administration & dosage , Paclitaxel/pharmacology , Piperazines/administration & dosage , Piperazines/pharmacology , Prostatic Neoplasms/genetics , Prostatic Neoplasms/metabolism , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Sulfonamides/administration & dosage , Tumor Suppressor Protein p53/metabolism
16.
Cell ; 137(6): 1062-75, 2009 Jun 12.
Article in English | MEDLINE | ID: mdl-19524509

ABSTRACT

Allelic loss of the essential autophagy gene beclin1 occurs in human cancers and renders mice tumor-prone suggesting that autophagy is a tumor-suppression mechanism. While tumor cells utilize autophagy to survive metabolic stress, autophagy also mitigates the resulting cellular damage that may limit tumorigenesis. In response to stress, autophagy-defective tumor cells preferentially accumulated p62/SQSTM1 (p62), endoplasmic reticulum (ER) chaperones, damaged mitochondria, reactive oxygen species (ROS), and genome damage. Moreover, suppressing ROS or p62 accumulation prevented damage resulting from autophagy defects indicating that failure to regulate p62 caused oxidative stress. Importantly, sustained p62 expression resulting from autophagy defects was sufficient to alter NF-kappaB regulation and gene expression and to promote tumorigenesis. Thus, defective autophagy is a mechanism for p62 upregulation commonly observed in human tumors that contributes directly to tumorigenesis likely by perturbing the signal transduction adaptor function of p62-controlling pathways critical for oncogenesis.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Autophagy , Neoplasms/metabolism , Aneuploidy , Animals , Apoptosis , Cell Line , Endoplasmic Reticulum/metabolism , Humans , Mice , Mitochondria/metabolism , Molecular Chaperones/metabolism , NF-kappa B/metabolism , Neoplasms/genetics , Oxidative Stress , Protein Disulfide-Isomerases/metabolism , Sequestosome-1 Protein , Transcription Factor TFIIH , Transcription Factors
17.
Carcinogenesis ; 29(3): 510-8, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18174247

ABSTRACT

Tissue transglutaminase (TG2) is a ubiquitously expressed enzyme capable of catalyzing protein cross-links. TG2-dependent cross-links are important in extracellular matrix integrity and it has been proposed that this TG2 activity establishes a barrier to tumor spread. Furthermore, TG2 controls sensitivity to the chemotherapeutic drug doxorubicin. Both doxorubicin sensitivity and TG2 expression are highly variable in cultured human breast cancer cell lines and inspection of the human gene (termed TGM2) determined that a canonical CpG island exists within its 5' flank. These features, when combined with its potential tumor suppressor activity, make TG2 an attractive candidate for epigenetic silencing. Consistent with this, we observed that culturing breast tumor cells with the DNA demethylating agent 5-aza-2'-deoxycytidine (5-azadC) resulted in a robust increase in TG2 expression. Analysis of DNA harvested from cultured lines and primary breast tumor samples indicated that TGM2 often displays aberrant hypermethylation and that there is a statistically significant correlation between gene methylation and reduced expression. Finally, we observed that doxorubicin-resistant MCF-7/ADR cells do not show TGM2 silencing but that doxorubicin-sensitive MCF-7 cells do and that culturing MCF-7 cells on 5-azadC and subsequently restoring TG2 expression reduced sensitivity to doxorubicin. This work indicates that the TGM2 gene is a target for epigenetic silencing in breast cancer and suggests that this aberrant molecular event is a potential marker for chemotherapeutic drug sensitivity.


Subject(s)
Antineoplastic Agents/pharmacology , Breast Neoplasms/genetics , Epigenesis, Genetic , GTP-Binding Proteins/genetics , Gene Silencing , Genetic Markers , Transglutaminases/genetics , Base Sequence , Cell Line, Tumor , DNA Methylation , DNA Primers , Drug Screening Assays, Antitumor , Electrophoresis, Polyacrylamide Gel , Humans , Protein Glutamine gamma Glutamyltransferase 2 , Reverse Transcriptase Polymerase Chain Reaction
18.
Genes Dev ; 21(11): 1367-81, 2007 Jun 01.
Article in English | MEDLINE | ID: mdl-17510285

ABSTRACT

Autophagy is a bulk degradation process that promotes survival under metabolic stress, but it can also be a means of cell death if executed to completion. Monoallelic loss of the essential autophagy gene beclin1 causes susceptibility to metabolic stress, but also promotes tumorigenesis. This raises the paradox that the loss of a survival pathway enhances tumor growth, where the exact mechanism is not known. Here, we show that compromised autophagy promoted chromosome instability. Failure to sustain metabolism through autophagy was associated with increased DNA damage, gene amplification, and aneuploidy, and this genomic instability may promote tumorigenesis. Thus, autophagy maintains metabolism and survival during metabolic stress that serves to protect the genome, providing an explanation for how the loss of a survival pathway leads to tumor progression. Identification of this novel role of autophagy may be important for rational chemotherapy and therapeutic exploitation of autophagy inducers as potential chemopreventive agents.


Subject(s)
Autophagy/physiology , Chromosomal Instability , Microtubule-Associated Proteins/physiology , Neoplasms/pathology , Proteins/physiology , Animals , Apoptosis , Apoptosis Regulatory Proteins , Aspartic Acid/analogs & derivatives , Aspartic Acid/pharmacology , Autophagy-Related Protein 5 , Beclin-1 , Blotting, Western , Cells, Cultured , Centrosome , Chromosome Aberrations , DNA Damage , Disease Progression , Epithelial Cells , Fluorescent Antibody Technique , Kidney/cytology , Loss of Heterozygosity , Metabolism/physiology , Mice , Mice, Knockout , Microtubule-Associated Proteins/genetics , Neoplasms/genetics , Neoplasms/metabolism , Phosphonoacetic Acid/analogs & derivatives , Phosphonoacetic Acid/pharmacology , Ploidies , Proteins/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Pyrimidines/biosynthesis , Signal Transduction
19.
Cancer Cell ; 10(1): 51-64, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16843265

ABSTRACT

Defective apoptosis renders immortalized epithelial cells highly tumorigenic, but how this is impacted by other common tumor mutations is not known. In apoptosis-defective cells, inhibition of autophagy by AKT activation or by allelic disruption of beclin1 confers sensitivity to metabolic stress by inhibiting an autophagy-dependent survival pathway. While autophagy acts to buffer metabolic stress, the combined impairment of apoptosis and autophagy promotes necrotic cell death in vitro and in vivo. Thus, inhibiting autophagy under conditions of nutrient limitation can restore cell death to apoptosis-refractory tumors, but this necrosis is associated with inflammation and accelerated tumor growth. Thus, autophagy may function in tumor suppression by mitigating metabolic stress and, in concert with apoptosis, by preventing death by necrosis.


Subject(s)
Autophagy/physiology , Inflammation/pathology , Neoplasms/pathology , Animals , Apoptosis/genetics , Apoptosis/physiology , Apoptosis Regulatory Proteins/genetics , Apoptosis Regulatory Proteins/metabolism , Beclin-1 , Cell Line, Transformed , Cell Survival/genetics , Cell Survival/physiology , Cell Transformation, Neoplastic/genetics , Disease Progression , HeLa Cells , Humans , Inflammation/genetics , Macrophages/metabolism , Macrophages/pathology , Mice , Mice, Knockout , Mice, Nude , Microscopy, Electron, Transmission , Models, Biological , NF-kappa B p50 Subunit/metabolism , Necrosis , Neoplasms/genetics , Neoplasms/ultrastructure , Proteins/genetics , Proteins/metabolism , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Transfection
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