Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 16 de 16
Filter
1.
J Pediatr ; 269: 113973, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38401785

ABSTRACT

OBJECTIVE: To test whether different clinical decision support tools increase clinician orders and patient completions relative to standard practice and each other. STUDY DESIGN: A pragmatic, patient-randomized clinical trial in the electronic health record was conducted between October 2019 and April 2020 at Geisinger Health System in Pennsylvania, with 4 arms: care gap-a passive listing recommending screening; alert-a panel promoting and enabling lipid screen orders; both; and a standard practice-no guideline-based notification-control arm. Data were analyzed for 13 346 9- to 11-year-old patients seen within Geisinger primary care, cardiology, urgent care, or nutrition clinics, or who had an endocrinology visit. Principal outcomes were lipid screening orders by clinicians and completions by patients within 1 week of orders. RESULTS: Active (care gap and/or alert) vs control arm patients were significantly more likely (P < .05) to have lipid screening tests ordered and completed, with ORs ranging from 1.67 (95% CI 1.28-2.19) to 5.73 (95% CI 4.46-7.36) for orders and 1.54 (95% CI 1.04-2.27) to 2.90 (95% CI 2.02-4.15) for completions. Alerts, with or without care gaps listed, outperformed care gaps alone on orders, with odds ratios ranging from 2.92 (95% CI 2.32-3.66) to 3.43 (95% CI 2.73-4.29). CONCLUSIONS: Electronic alerts can increase lipid screening orders and completions, suggesting clinical decision support can improve guideline-concordant screening. The study also highlights electronic record-based patient randomization as a way to determine relative effectiveness of support tools. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04118348.


Subject(s)
Decision Support Systems, Clinical , Mass Screening , Humans , Child , Male , Female , Mass Screening/methods , Lipids/blood , Electronic Health Records
2.
J Appl Res Intellect Disabil ; 35(3): 867-877, 2022 May.
Article in English | MEDLINE | ID: mdl-35277898

ABSTRACT

BACKGROUND: Few family caregivers of individuals with intellectual or developmental disabilities develop long-term care (LTC) plans for their relative. Web-based interventions promoting LTC planning have potential for widespread adoption into clinical practice. METHODS: We conducted focus groups with 49 primary caregivers of individuals with intellectual or developmental disabilities in NY, PA, OH, DE, and TX to identify barriers and facilitators of LTC planning, review existing tools, and identify critical features for web-based LTC planning interventions. Participants also answered questions on demographic characteristics and functional status. RESULTS: NVivo qualitative analysis software was used to analyse focus groups using a grounded theory approach. Caregivers identified web tool accessibility and topics such as finances, housing, and government benefits as critical. Caregivers also described desired features for a LTC planning tool. CONCLUSIONS: This study identified desired characteristics of web-based LTC planning tools and ways in which existing web-based interventions might be adapted or enhanced.


Subject(s)
Intellectual Disability , Internet-Based Intervention , Caregivers , Child , Developmental Disabilities , Humans , Long-Term Care
3.
J Pediatr Rehabil Med ; 14(4): 605-612, 2021.
Article in English | MEDLINE | ID: mdl-34864698

ABSTRACT

PURPOSE: Transitional care for adolescents with complex diseases, who are entering adulthood, is challenging. The purpose of this study is to quantify the disease and medication burden of this population, who are transitioning though an interdisciplinary specialty clinic. METHODS: This study is a retrospective observational study of all patients seen in a transitional care clinic between July 2012 and March 2015. The main outcomes assessed included disease state and medication burden. Descriptive statistics, along with the paired t-test and McNemar's test, were used. RESULTS: The study cohort included 216 patients. The median patient age was 20.7 years, and the median number of clinic encounters was 6. Patients had at least 1 of 8 primary diagnoses. On average, patients took medications from 5 classes and used 3 dose forms. Among 163 patients who had medication reconciliation performed, the average number of medication classes increased by 0.44±1.53 (p = 0.0003). There was an average increase of 3.70%(SD±36.31%; p = 0.27) in the number of required medication lab assessments ordered for patients who had medication reconciliation performed. CONCLUSION: There is a high disease and medication burden among adolescent patients with complex disease states who are to transition to adult care.


Subject(s)
Transitional Care , Adolescent , Adult , Ambulatory Care , Humans , Medication Reconciliation , Pharmacists , Retrospective Studies , Young Adult
4.
Mol Cancer Ther ; 18(1): 3-16, 2019 01.
Article in English | MEDLINE | ID: mdl-30352802

ABSTRACT

PTC299 was identified as an inhibitor of VEGFA mRNA translation in a phenotypic screen and evaluated in the clinic for treatment of solid tumors. To guide precision cancer treatment, we performed extensive biological characterization of the activity of PTC299 and demonstrated that inhibition of VEGF production and cell proliferation by PTC299 is linked to a decrease in uridine nucleotides by targeting dihydroorotate dehydrogenase (DHODH), a rate-limiting enzyme for de novo pyrimidine nucleotide synthesis. Unlike previously reported DHODH inhibitors that were identified using in vitro enzyme assays, PTC299 is a more potent inhibitor of DHODH in isolated mitochondria suggesting that mitochondrial membrane lipid engagement in the DHODH conformation in situ is required for its optimal activity. PTC299 has broad and potent activity against hematologic cancer cells in preclinical models, reflecting a reduced pyrimidine nucleotide salvage pathway in leukemia cells. Archived serum samples from patients treated with PTC299 demonstrated increased levels of dihydroorotate, the substrate of DHODH, indicating target engagement in patients. PTC299 has advantages over previously reported DHODH inhibitors, including greater potency, good oral bioavailability, and lack of off-target kinase inhibition and myelosuppression, and thus may be useful for the targeted treatment of hematologic malignancies.


Subject(s)
Hematologic Neoplasms/drug therapy , Imidazoles/administration & dosage , Oxidoreductases Acting on CH-CH Group Donors/antagonists & inhibitors , Thiazoles/administration & dosage , Vascular Endothelial Growth Factor A/genetics , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Dihydroorotate Dehydrogenase , Hematologic Neoplasms/blood , Hematologic Neoplasms/enzymology , Humans , Imidazoles/pharmacology , K562 Cells , Mice , Oxidoreductases Acting on CH-CH Group Donors/blood , Thiazoles/pharmacology , Xenograft Model Antitumor Assays
5.
Oncogene ; 38(10): 1702-1716, 2019 03.
Article in English | MEDLINE | ID: mdl-30348991

ABSTRACT

Medulloblastoma (MB) is the most frequent malignant pediatric brain tumor, representing 20% of newly diagnosed childhood central nervous system malignancies. Although advances in multimodal therapy yielded a 5-year survivorship of 80%, MB still accounts for the leading cause of childhood cancer mortality. In this work, we describe the epigenetic regulator BMI1 as a novel therapeutic target for the treatment of recurrent human Group 3 MB, a childhood brain tumor for which there is virtually no treatment option beyond palliation. Current clinical trials for recurrent MB patients based on genomic profiles of primary, treatment-naive tumors will provide limited clinical benefit since recurrent metastatic MBs are highly genetically divergent from their primary tumor. Using a small molecule inhibitor against BMI1, PTC-028, we were able to demonstrate complete ablation of self-renewal of MB stem cells in vitro. When administered to mice xenografted with patient tumors, we observed significant reduction in tumor burden in both local and metastatic compartments and subsequent increased survival, without neurotoxicity. Strikingly, serial in vivo re-transplantation assays demonstrated a marked reduction in tumor initiation ability of recurrent MB cells upon re-transplantation of PTC-028-treated cells into secondary recipient mouse brains. As Group 3 MB is often metastatic and uniformly fatal at recurrence, with no current or planned trials of targeted therapy, an efficacious targeted agent would be rapidly transitioned to clinical trials.


Subject(s)
Cerebellar Neoplasms/drug therapy , Medulloblastoma/drug therapy , Neoplastic Stem Cells/drug effects , Polycomb Repressive Complex 1/antagonists & inhibitors , Small Molecule Libraries/administration & dosage , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cerebellar Neoplasms/genetics , Cerebellar Neoplasms/metabolism , Child , Epigenesis, Genetic , Gene Expression Regulation, Neoplastic/drug effects , Humans , Medulloblastoma/genetics , Medulloblastoma/metabolism , Mice , Neoplastic Stem Cells/cytology , Neoplastic Stem Cells/metabolism , Polycomb Repressive Complex 1/genetics , Small Molecule Libraries/pharmacology , Treatment Outcome , Up-Regulation/drug effects , Xenograft Model Antitumor Assays
6.
Popul Health Manag ; 20(6): 435-441, 2017 12.
Article in English | MEDLINE | ID: mdl-28338416

ABSTRACT

Adolescents and young adults with special care and health needs in the United States-many of whom have Medicaid coverage-at the transition phase between pediatric and adult care often experience critical care gaps. To address this challenge, a new model-referred to as Comprehensive Care Clinic (CCC)-has been developed and implemented by Geisinger Health System since 2012. CCC comprises a care team, consisting of a generalist physician, advanced practitioner, pharmacist, and a nurse case manager, that develops and closely follows a coordinated care plan. This study examines the CCC impact on total cost of care and utilization by analyzing Geisinger Health Plan claims data obtained from 83 Medicaid patients enrolled in CCC. A set of multivariate regression models with patient fixed effects was estimated to obtain adjusted differences in cost and acute care utilization between the months in which the patients were enrolled and the months not enrolled in CCC. The results indicate that CCC enrollment was associated with a 28% reduction in per-member-per-month total cost ($3931 observed vs. $5451 expected; P = 0.028), driven by reductions in hospitalization and emergency department visits. This finding suggests a clinical redesign focused on adolescent and young adults with complex care needs can potentially reduce total cost and acute care utilization among such patients.


Subject(s)
Comprehensive Health Care/economics , Delivery of Health Care/economics , Adolescent , Adult , Autistic Disorder/economics , Autistic Disorder/therapy , Critical Care/economics , Critical Care/statistics & numerical data , Emergency Service, Hospital/statistics & numerical data , Hospitalization/statistics & numerical data , Humans , Medicaid , Spinal Dysraphism/economics , Spinal Dysraphism/therapy , United States , Young Adult
7.
RNA ; 23(4): 567-577, 2017 04.
Article in English | MEDLINE | ID: mdl-28096517

ABSTRACT

Nonsense mutations resulting in a premature stop codon in an open reading frame occur in critical tumor suppressor genes in a large number of the most common forms of cancers and are known to cause or contribute to the progression of disease. Low molecular weight compounds that induce readthrough of nonsense mutations offer a new means of treating patients with genetic disorders or cancers resulting from nonsense mutations. We have identified the nucleoside analog clitocine as a potent and efficacious suppressor of nonsense mutations. We determined that incorporation of clitocine into RNA during transcription is a prerequisite for its readthrough activity; the presence of clitocine in the third position of a premature stop codon directly induces readthrough. We demonstrate that clitocine can induce the production of p53 protein in cells harboring p53 nonsense-mutated alleles. In these cells, clitocine restored production of full-length and functional p53 as evidenced by induced transcriptional activation of downstream p53 target genes, progression of cells into apoptosis, and impeded growth of nonsense-containing human ovarian cancer tumors in xenograft tumor models. Thus, clitocine induces readthrough of nonsense mutations by a previously undescribed mechanism and represents a novel therapeutic modality to treat cancers and genetic diseases caused by nonsense mutations.


Subject(s)
Antimetabolites, Antineoplastic/pharmacology , Biomimetic Materials/pharmacology , Codon, Nonsense/drug effects , Furans/pharmacology , Nucleosides/pharmacology , Ovarian Neoplasms/drug therapy , Pyrimidine Nucleosides/pharmacology , Tumor Suppressor Protein p53/agonists , Animals , Antimetabolites, Antineoplastic/chemical synthesis , Antimetabolites, Antineoplastic/metabolism , Apoptosis/drug effects , Biomimetic Materials/chemical synthesis , Biomimetic Materials/metabolism , Cell Line, Tumor , Female , Furans/chemical synthesis , Furans/metabolism , Genes, Reporter , Humans , Luciferases/genetics , Luciferases/metabolism , Mice , Mice, Nude , Nucleosides/chemical synthesis , Nucleosides/metabolism , Ovarian Neoplasms/genetics , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Protein Biosynthesis , Pyrimidine Nucleosides/chemical synthesis , Pyrimidine Nucleosides/metabolism , Signal Transduction , Transcriptional Activation , Tumor Burden/drug effects , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Xenograft Model Antitumor Assays
8.
PLoS One ; 11(12): e0168366, 2016.
Article in English | MEDLINE | ID: mdl-27992500

ABSTRACT

Current anti-VEGF (Vascular Endothelial Growth Factor A) therapies to treat various cancers indiscriminately block VEGF function in the patient resulting in the global loss of VEGF signaling which has been linked to dose-limiting toxicities as well as treatment failures due to acquired resistance. Accumulating evidence suggests that this resistance is at least partially due to increased production of compensatory tumor angiogenic factors/cytokines. VEGF protein production is differentially controlled depending on whether cells are in the normal "homeostatic" state or in a stressed state, such as hypoxia, by post-transcriptional regulation imparted by elements in the 5' and 3' untranslated regions (UTR) of the VEGF mRNA. Using the Gene Expression Modulation by Small molecules (GEMS™) phenotypic assay system, we performed a high throughput screen to identify low molecular weight compounds that target the VEGF mRNA UTR-mediated regulation of stress-induced VEGF production in tumor cells. We identified a number of compounds that potently and selectively reduce endogenous VEGF production under hypoxia in HeLa cells. Medicinal chemistry efforts improved the potency and pharmaceutical properties of one series of compounds resulting in the discovery of PTC-510 which inhibits hypoxia-induced VEGF expression in HeLa cells at low nanomolar concentration. In mouse xenograft studies, oral administration of PTC-510 results in marked reduction of intratumor VEGF production and single agent control of tumor growth without any evident toxicity. Here, we show that selective suppression of stress-induced VEGF production within tumor cells effectively controls tumor growth. Therefore, this approach may minimize the liabilities of current global anti-VEGF therapies.


Subject(s)
Angiogenesis Inhibitors/administration & dosage , Antineoplastic Agents/administration & dosage , High-Throughput Screening Assays/methods , Neoplasms/drug therapy , Untranslated Regions/drug effects , Vascular Endothelial Growth Factor A/genetics , Administration, Oral , Angiogenesis Inhibitors/pharmacology , Animals , Antineoplastic Agents/pharmacology , Cell Hypoxia , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , HEK293 Cells , HeLa Cells , Hep G2 Cells , Humans , Mice , Neoplasms/genetics , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Xenograft Model Antitumor Assays
9.
Sci Transl Med ; 8(350): 350ra104, 2016 08 03.
Article in English | MEDLINE | ID: mdl-27488898

ABSTRACT

Lung cancer is the most common cause of cancer deaths. The expression of the transcription factor C/EBPα (CCAAT/enhancer binding protein α) is frequently lost in non-small cell lung cancer, but the mechanisms by which C/EBPα suppresses tumor formation are not fully understood. In addition, no pharmacological therapy is available to specifically target C/EBPα expression. We discovered a subset of pulmonary adenocarcinoma patients in whom negative/low C/EBPα expression and positive expression of the oncogenic protein BMI1 (B lymphoma Mo-MLV insertion region 1 homolog) have prognostic value. We also generated a lung-specific mouse model of C/EBPα deletion that develops lung adenocarcinomas, which are prevented by Bmi1 haploinsufficiency. BMI1 activity is required for both tumor initiation and maintenance in the C/EBPα-null background, and pharmacological inhibition of BMI1 exhibits antitumor effects in both murine and human adenocarcinoma lines. Overall, we show that C/EBPα is a tumor suppressor in lung cancer and that BMI1 is required for the oncogenic process downstream of C/EBPα loss. Therefore, anti-BMI1 pharmacological inhibition may offer a therapeutic benefit for lung cancer patients with low expression of C/EBPα and high BMI1.


Subject(s)
Adenocarcinoma/pathology , Adenocarcinoma/therapy , CCAAT-Enhancer-Binding Protein-alpha/metabolism , Lung Neoplasms/pathology , Lung Neoplasms/therapy , Polycomb Repressive Complex 1/metabolism , Proto-Oncogene Proteins/metabolism , Adenocarcinoma/genetics , Adenocarcinoma/metabolism , Adenocarcinoma of Lung , Animals , CCAAT-Enhancer-Binding Protein-alpha/genetics , Gene Expression Regulation, Neoplastic/genetics , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Mice , Mice, Knockout , Mutation/genetics , Polycomb Repressive Complex 1/genetics , Proto-Oncogene Proteins/genetics
10.
Clin Cancer Res ; 22(24): 6176-6191, 2016 Dec 15.
Article in English | MEDLINE | ID: mdl-27307599

ABSTRACT

PURPOSE: Current prostate cancer management calls for identifying novel and more effective therapies. Self-renewing tumor-initiating cells (TICs) hold intrinsic therapy resistance and account for tumor relapse and progression. As BMI-1 regulates stem cell self-renewal, impairing BMI-1 function for TIC-tailored therapies appears to be a promising approach. EXPERIMENTAL DESIGN: We have previously developed a combined immunophenotypic and time-of-adherence assay to identify CD49bhiCD29hiCD44hi cells as human prostate TICs. We utilized this assay with patient-derived prostate cancer cells and xenograft models to characterize the effects of pharmacologic inhibitors of BMI-1. RESULTS: We demonstrate that in cell lines and patient-derived TICs, BMI-1 expression is upregulated and associated with stem cell-like traits. From a screened library, we identified a number of post-transcriptional small molecules that target BMI-1 in prostate TICs. Pharmacologic inhibition of BMI-1 in patient-derived cells significantly decreased colony formation in vitro and attenuated tumor initiation in vivo, thereby functionally diminishing the frequency of TICs, particularly in cells resistant to proliferation- and androgen receptor-directed therapies, without toxic effects on normal tissues. CONCLUSIONS: Our data offer a paradigm for targeting TICs and support the development of BMI-1-targeting therapy for a more effective prostate cancer treatment. Clin Cancer Res; 22(24); 6176-91. ©2016 AACR.


Subject(s)
Antineoplastic Agents/pharmacology , Cell Self Renewal/drug effects , Cell Survival/drug effects , Neoplastic Stem Cells/drug effects , Polycomb Repressive Complex 1/metabolism , Prostatic Neoplasms/metabolism , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Transformation, Neoplastic/drug effects , Cell Transformation, Neoplastic/metabolism , Humans , Male , Mice , Mice, Inbred NOD , Mice, SCID , Neoplastic Stem Cells/metabolism , Prostatic Neoplasms/drug therapy , Receptors, Androgen/metabolism , Xenograft Model Antitumor Assays/methods
11.
J Cell Biochem ; 112(10): 2729-41, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21678481

ABSTRACT

Growing evidence has demonstrated that clonogenic cancer stem (initiating) cells are responsible for tumor regrowth and disease relapse. Bmi-1 plays a critical role in the self-renewal of adult stem cells. The Bmi-1 protein is elevated in many types of cancers, and experimental reduction of Bmi-1 protein levels by small interfering RNA (siRNA) causes apoptosis and/or senescence in tumor cells in vitro and increases susceptibility to cytotoxic agents. The Bmi-1 protein has no known enzymatic activity, but serves as the key regulatory component of the PRC1 complex (polycomb repressive complex-1). This complex influences chromatin structure and regulates transcriptional activity of a number of important loci including the Ink4a locus which encodes the tumor suppressor proteins p16(Ink4a) and p14(Arf) . In this prospective study, we will discuss the implication of BMI1 in cancers, the biology of BMI1, and the regulatory control of BMI1 expression. The target validation and the future prospects of targeting BMI1 in cancer therapy are also discussed.


Subject(s)
Nuclear Proteins/metabolism , Proto-Oncogene Proteins/metabolism , Repressor Proteins/metabolism , Animals , Humans , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Nuclear Proteins/genetics , Polycomb Repressive Complex 1 , Polycomb-Group Proteins , Proto-Oncogene Proteins/genetics , Repressor Proteins/genetics
12.
Cancer Res ; 64(1): 279-85, 2004 Jan 01.
Article in English | MEDLINE | ID: mdl-14729635

ABSTRACT

Previous work has demonstrated that selective cyclooxygenase-2 (COX-2) inhibitors can act synergistically with radiotherapy to improve tumor debulking and control in preclinical models. The underlying mechanism of this remarkable activity has not yet been determined. Here, we report that radiation can elevate intratumoral levels of COX-2 protein and its products, particularly prostaglandin E(2) (PGE(2)). Furthermore, inhibition of COX-2 activity or neutralization of PGE(2) activity enhances radiotherapy even in tumors where COX-2 expression is restricted to the tumor neovasculature. Direct assessment of vascular function by direct contrast enhancement-magnetic resonance imaging showed that the combination of radiation and celecoxib lead to enhanced vascular permeability. These observations suggest that an important mechanism of celecoxib-induced radiosensitization involves inhibition of COX-2-derived PGE(2), thus removing a survival factor for the tumor and its vasculature.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma/drug therapy , Carcinoma/radiotherapy , Colonic Neoplasms/drug therapy , Colonic Neoplasms/radiotherapy , Cyclooxygenase Inhibitors/therapeutic use , Dinoprostone/antagonists & inhibitors , Isoenzymes/metabolism , Prostaglandin-Endoperoxide Synthases/metabolism , Sulfonamides/therapeutic use , Animals , Celecoxib , Combined Modality Therapy , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Disease Models, Animal , Humans , Kinetics , Membrane Proteins , Mice , Mice, Inbred BALB C , Pyrazoles , Time Factors
13.
J Pharmacol Exp Ther ; 308(3): 929-34, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14711936

ABSTRACT

There have been a number of reports suggesting inhibition of prostaglandin production may impact tumor-mediated wasting and levels of associated humoral factors such as hypercalcemia. These reductions were achieved using traditional nonsteroidal anti-inflammatory drugs (NSAIDs), which are often contraindicated in cancer patients. This is especially true during chemotherapeutic regimens due to concerns of bleeding from gastrointestinal and hematopoietic toxicities associated with inhibition of the housekeeping cyclooxygenase enzyme COX-1. Here, we report that celecoxib, one of the new class of selective COX-2 inhibitors, has the potential to reverse tumor-mediated wasting and associated humoral factors such as interleukin (IL)-6 and hypercalcemia in preclinical models of cachexia. Tumor bearing mice in late stage cachexia regained weight within days of the start of celecoxib treatment. Two models were tested. The first was the Colon 26 (Col26) syngeneic murine model that induces high levels of circulating IL-6 and hypercalcemia. The second was the human head and neck 1483 HNSCC xenograft model, which is less inflammatory and produces less prostaglandin than Col26. Despite the observation that no significant impact on tumor growth was observed between vehicle and celecoxib-treated animals over the course of the studies, celecoxib rapidly reversed weight loss in both cachectic models. With the added safety of celecoxib over traditional NSAIDs, these results suggest a possible therapeutic use for celecoxib for treating tumor-mediated wasting.


Subject(s)
Cyclooxygenase Inhibitors/pharmacology , Isoenzymes/metabolism , Prostaglandin-Endoperoxide Synthases/metabolism , Sulfonamides/pharmacology , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Blood Glucose/metabolism , Calcium/metabolism , Celecoxib , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Eating/drug effects , Interleukin-6/metabolism , Mice , Prostaglandins/metabolism , Pyrazoles , Tumor Cells, Cultured
14.
Am J Clin Oncol ; 26(4): S58-61, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12902857

ABSTRACT

Prostaglandins have long been known to impact the radiosensitivity of cells and tissues, and many studies have centered on exploiting nonspecific prostaglandin inhibitors such as NSAIDs for therapeutic gain. These studies have ultimately been unsuccessful due to the lack of targeted specificity against the tumor. The discovery of the inducible cyclooxygenase enzyme (COX-2) and development of some highly selective inhibitors (which spare the constitutive COX-1 activity) has renewed excitement for modulating tumor prostaglandins as a method of specific radiosensitization of tumors, while sparing normal tissues. This review discusses these new data and generates a rationale for use of COX-2 inhibitors as radiosensitizing agents in cancer therapy.


Subject(s)
Antineoplastic Agents/therapeutic use , Cyclooxygenase Inhibitors/therapeutic use , Isoenzymes/antagonists & inhibitors , Neoplasms/drug therapy , Neoplasms/radiotherapy , Radiation-Sensitizing Agents/therapeutic use , Animals , Antineoplastic Agents/pharmacology , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Cyclooxygenase Inhibitors/pharmacology , Humans , Membrane Proteins , Prostaglandin-Endoperoxide Synthases , Prostaglandins/pharmacology , Prostaglandins/therapeutic use , Radiation-Sensitizing Agents/pharmacology
15.
Cancer Res ; 62(22): 6706-11, 2002 Nov 15.
Article in English | MEDLINE | ID: mdl-12438270

ABSTRACT

Both nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase (COX) 2-selective inhibitors such as celecoxib are being reported as having potent anticancer activity in laboratory models. Several reports have suggested that the mechanism of action of these agents in reducing tumor volume/burden is unrelated to their inhibition of prostaglandin synthesis. Many in vitro reports use supraphysiological concentrations of these drugs to demonstrate COX-independent activities on apoptosis or proliferation. In vivo, most murine tumor models express COX-2 only in the vasculature and stroma, unlike human tumors that also express COX-2 in the tumor cells. In general, these models have the limitation of having no measurable, COX-2-derived, prostaglandins, the inhibition of which correlates with antitumor efficacy. We report here that 1483 human head and neck xenograft tumors express COX-2 similar to the pattern observed in human solid tumors and that COX-2 activity produces high levels of prostaglandin E2 (PGE2). Inhibition of COX-2 by celecoxib resulted in loss of intratumor PGE2 levels and reduced tumor growth in a dose-dependent manner. In contrast, a selective COX-1 inhibitor, SC-560, did not measurably reduce tumor prostaglandin levels or tumor growth despite the presence of COX-1 in the host and tumor cells. Celecoxib-treated tumors showed reduced proliferation and increased apoptosis of both tumor and stromal cells compared with vehicle controls. Specific inhibition of PGE2 activity by a neutralizing antibody mimicked the reduced tumor growth observed after celecoxib treatment, suggesting growth is PGE2 mediated. These data indicate that a major antitumor mechanism of action of celecoxib is inhibition of COX-2-derived prostaglandins, particularly PGE2, and suggest celecoxib as a novel therapeutic agent for human head and neck cancer.


Subject(s)
Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Dinoprostone/physiology , Head and Neck Neoplasms/metabolism , Head and Neck Neoplasms/pathology , Isoenzymes/metabolism , Prostaglandin-Endoperoxide Synthases/metabolism , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Apoptosis/drug effects , Apoptosis/physiology , Carcinoma, Squamous Cell/enzymology , Celecoxib , Cell Division/drug effects , Cell Division/physiology , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Cyclooxygenase Inhibitors/pharmacology , Dinoprostone/antagonists & inhibitors , Dinoprostone/biosynthesis , Head and Neck Neoplasms/enzymology , Humans , Ileum/cytology , Ileum/drug effects , Intestinal Mucosa/cytology , Intestinal Mucosa/drug effects , Isoenzymes/antagonists & inhibitors , Male , Membrane Proteins , Mice , Mice, Nude , Neoplasm Transplantation , Pyrazoles , Sulfonamides/pharmacology , Transplantation, Heterologous , Tumor Cells, Cultured
16.
Cancer Res ; 62(20): 5778-84, 2002 Oct 15.
Article in English | MEDLINE | ID: mdl-12384538

ABSTRACT

Combining anticancer drugs with different mechanisms of action has the potential to enhance antitumor effect. CPT-11 (Camptosar, irinotecan), a topoisomerase I inhibitor, has been shown to be highly effective in the treatment of a variety of cancers. However, its clinical usage is often complicated by late diarrhea. A number of studies have shown that cyclooxygenase (COX)-2 is overexpressed in many forms of human tumors, suggesting that COX-2 inhibition may be useful in the treatment of cancer. In this study, we used two mouse tumor models (HT-29 and colon-26 cells) to evaluate the effect of combining CPT-11 with celecoxib on tumor growth. We also assessed the involvement of COX-2 in the pathogenesis of CPT-11-induced late diarrhea using a rat model. Results indicate that celecoxib enhances the antitumor effect of CPT-11 and reduces the severity of late diarrhea in a dose-dependent manner. The extended benefits of combining celecoxib with CPT-11 may significantly improve the outcome of cancer patients.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Camptothecin/analogs & derivatives , Camptothecin/pharmacology , Cyclooxygenase Inhibitors/pharmacology , Diarrhea/prevention & control , Isoenzymes/antagonists & inhibitors , Sulfonamides/pharmacology , Animals , Camptothecin/administration & dosage , Camptothecin/adverse effects , Celecoxib , Colon/metabolism , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Diarrhea/chemically induced , Dinoprostone/biosynthesis , Dinoprostone/physiology , Drug Administration Schedule , Drug Synergism , HT29 Cells/drug effects , Humans , Irinotecan , Male , Membrane Proteins , Mice , Mice, Inbred BALB C , Mice, Nude , Prostaglandin-Endoperoxide Synthases , Pyrazoles , Rats , Rats, Sprague-Dawley , Sulfonamides/administration & dosage , Weight Loss/drug effects , Xenograft Model Antitumor Assays
SELECTION OF CITATIONS
SEARCH DETAIL
...