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1.
Cancer Discov ; 14(7): 1276-1301, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38533987

RESUMO

Cancer homeostasis depends on a balance between activated oncogenic pathways driving tumorigenesis and engagement of stress response programs that counteract the inherent toxicity of such aberrant signaling. Although inhibition of oncogenic signaling pathways has been explored extensively, there is increasing evidence that overactivation of the same pathways can also disrupt cancer homeostasis and cause lethality. We show here that inhibition of protein phosphatase 2A (PP2A) hyperactivates multiple oncogenic pathways and engages stress responses in colon cancer cells. Genetic and compound screens identify combined inhibition of PP2A and WEE1 as synergistic in multiple cancer models by collapsing DNA replication and triggering premature mitosis followed by cell death. This combination also suppressed the growth of patient-derived tumors in vivo. Remarkably, acquired resistance to this drug combination suppressed the ability of colon cancer cells to form tumors in vivo. Our data suggest that paradoxical activation of oncogenic signaling can result in tumor-suppressive resistance. Significance: A therapy consisting of deliberate hyperactivation of oncogenic signaling combined with perturbation of the stress responses that result from this is very effective in animal models of colon cancer. Resistance to this therapy is associated with loss of oncogenic signaling and reduced oncogenic capacity, indicative of tumor-suppressive drug resistance.


Assuntos
Neoplasias do Colo , Proteína Fosfatase 2 , Transdução de Sinais , Humanos , Animais , Proteína Fosfatase 2/metabolismo , Camundongos , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Neoplasias do Colo/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Resistencia a Medicamentos Antineoplásicos , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Replicação do DNA
2.
Bioanalysis ; 15(17): 1095-1107, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37584370

RESUMO

We have developed and validated a novel LC-MS/MS method for the simultaneous quantification of LB-100 and its active metabolite, endothall, in human plasma following solid-phase extraction. LB-105 and endothall-D6 were used as internal standards. Chromatographic separation was achieved on a Hypercarb™ column using 5 mM (NH4)2CO3 and 30:70 (v/v) 100 mM (NH4)2CO3:acetonitrile as mobile phases. Detection was performed via positive electrospray ionization mode with multiple reaction monitoring. The assay exhibited linearity in the concentration range of 2.5-500 ng/ml for both analytes. Intra- and inter-assay precision and accuracy were within ±11%. LB-100 and endothall recoveries were 78.7 and 86.7%, respectively. The validated LC-MS/MS method enabled the accurate measurement of LB-100 and endothall in patient samples from an ongoing clinical trial (NCT04560972).


Assuntos
Espectrometria de Massas em Tandem , Humanos , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos , Padrões de Referência , Reprodutibilidade dos Testes , Cromatografia Líquida de Alta Pressão/métodos
4.
Mol Cancer Ther ; 20(10): 1820-1835, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34253596

RESUMO

Protein phosphatase 2A (PP2A), a serine/threonine phosphatase involved in the regulation of apoptosis, proliferation, and DNA-damage response, is overexpressed in many cancers, including small cell lung cancer (SCLC). Here we report that LB100, a small molecule inhibitor of PP2A, when combined with platinum-based chemotherapy, synergistically elicited an antitumor response both in vitro and in vivo with no apparent toxicity. Using inductively coupled plasma mass spectrometry, we determined quantitatively that sensitization via LB100 was mediated by increased uptake of carboplatin in SCLC cells. Treatment with LB100 alone or in combination resulted in inhibition of cell viability in two-dimensional culture and three-dimensional spheroid models of SCLC, reduced glucose uptake, and attenuated mitochondrial and glycolytic ATP production. Combining LB100 with atezolizumab increased the capacity of T cells to infiltrate and kill tumor spheroids, and combining LB100 with carboplatin caused hyperphosphorylation of the DNA repair marker γH2AX and enhanced apoptosis while attenuating MET signaling and invasion through an endothelial cell monolayer. Taken together, these data highlight the translational potential of inhibiting PP2A with LB100 in combination with platinum-based chemotherapy and immunotherapy in SCLC.


Assuntos
Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Piperazinas/farmacologia , Proteína Fosfatase 2/antagonistas & inibidores , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Antineoplásicos/farmacologia , Apoptose , Proliferação de Células , Humanos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Carcinoma de Pequenas Células do Pulmão/enzimologia , Carcinoma de Pequenas Células do Pulmão/patologia , Células Tumorais Cultivadas
5.
J Neurooncol ; 148(2): 231-244, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32342332

RESUMO

PURPOSE: Glioblastoma (GBM) carries a dismal prognosis despite standard multimodal treatment with surgery, chemotherapy and radiation. Immune checkpoint inhibitors, such as PD1 blockade, for treatment of GBM failed to show clinical benefit. Rational combination strategies to overcome resistance of GBM to checkpoint monotherapy are needed to extend the promise of immunotherapy to GBM management. Emerging evidence suggests that protein phosphatase 2A (PP2A) plays a critical role in the signal transduction pathways of both adaptive and innate immune cells and that inhibition of PP2A could enhance cancer immunity. We investigated the use of a PP2A inhibitor, LB-100, to enhance antitumor efficacy of PD1 blockade in a syngeneic glioma model. METHODS: C57BL/6 mice were implanted with murine glioma cell line GL261-luc or GL261-WT and randomized into 4 treatment arms: (i) control, (ii) LB-100, (iii) PD1 blockade and (iv) combination. Survival was assessed and detailed profiling of tumor infiltrating leukocytes was performed. RESULTS: Dual PP2A and PD1 blockade significantly improved survival compared with monotherapy alone. Combination therapy resulted in complete regression of tumors in about 25% of mice. This effect was dependent on CD4 and CD8 T cells and cured mice established antigen-specific secondary protective immunity. Analysis of tumor lymphocytes demonstrated enhanced CD8 infiltration and effector function. CONCLUSION: This is the first preclinical investigation of the effect of combining PP2A inhibition with PD1 blockade for GBM. This novel combination provided effective tumor immunotherapy and long-term survival in our animal GBM model.


Assuntos
Antineoplásicos Imunológicos/administração & dosagem , Neoplasias Encefálicas/imunologia , Glioblastoma/imunologia , Piperazinas/administração & dosagem , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Proteína Fosfatase 2/antagonistas & inibidores , Animais , Neoplasias Encefálicas/prevenção & controle , Linhagem Celular Tumoral , Quimioterapia Combinada/métodos , Feminino , Glioblastoma/prevenção & controle , Camundongos Endogâmicos C57BL , Receptor de Morte Celular Programada 1/imunologia , Proteína Fosfatase 2/imunologia
6.
Cancers (Basel) ; 12(1)2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31935881

RESUMO

Chimeric antigen receptor (CAR)-engineered T cells represent a promising modality for treating glioblastoma. Recently, we demonstrated that CAR-T cells targeting carbonic anhydrase IX (CAIX), a protein involved in HIF-1a hypoxic signaling, is a promising CAR-T cell target in an intracranial murine glioblastoma model. Anti-CAIX CAR-T cell therapy is limited by its suboptimal activation within the tumor microenvironment. LB-100, a small molecular inhibitor of protein phosphatase 2A (PP2A), has been shown to enhance T cell anti-tumor activity through activation of the mTOR signaling pathway. Herein, we investigated if a treatment strategy consisting of a combination of LB-100 and anti-CAIX CAR-T cell therapy produced a synergistic anti-tumor effect. Our studies demonstrate that LB-100 enhanced anti-CAIX CAR-T cell treatment efficacy in vitro and in vivo. Our findings demonstrate the role of LB-100 in augmenting the cytotoxic activity of anti-CAIX CAR-T cells and underscore the synergistic therapeutic potential of applying combination LB-100 and CAR-T Cell therapy to other solid tumors.

7.
Nat Commun ; 9(1): 2126, 2018 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-29844427

RESUMO

Mounting evidence suggests that inhibition of protein phosphatase-2A (PP2A), a serine/threonine phosphatase, could enhance anticancer immunity. However, drugs targeting PP2A are not currently available. Here, we report that a PP2A inhibitor, LB-100, when combined with anti-PD-1 (aPD-1) blockade can synergistically elicit a durable immune-mediated antitumor response in a murine CT26 colon cancer model. This effect is T-cell dependent, leading to regression of a significant proportion of tumors. Analysis of tumor lymphocytes demonstrates enhanced effector T-cell and reduced suppressive regulatory T-cell infiltration. Clearance of tumor establishes antigen-specific secondary protective immunity. A synergistic effect of LB-100 and aPD-1 blockade is also observed in B16 melanoma model. In addition, LB-100 activates the mTORC1 signaling pathway resulting in decreased differentiation of naive CD4 cells into regulatory T cells. There is also increased expression of Th1 and decreased expression of Th2 cytokines. These data highlight the translational potential of PP2A inhibition in combination with checkpoint inhibition.


Assuntos
Antineoplásicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Neoplasias do Colo/terapia , Imunoterapia/métodos , Linfócitos do Interstício Tumoral/imunologia , Melanoma Experimental/terapia , Piperazinas/farmacologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Proteína Fosfatase 2/antagonistas & inibidores , Linfócitos T Reguladores/imunologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Neoplasias do Colo/imunologia , Feminino , Humanos , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Células Th1/imunologia , Células Th2/imunologia
8.
Clin Cancer Res ; 23(13): 3277-3284, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28039265

RESUMO

Purpose: To determine the MTD and to assess the safety, tolerability, and potential activity of LB-100, a first-in-class small-molecule inhibitor of protein phosphatase 2A (PP2A) in adult patients with progressive solid tumors.Experimental Design: LB-100 was administered intravenously daily for 3 days in 21-day cycles in a 3 + 3 dose escalation design.Results: There were 29 patient entries over 7 dose escalations. One patient stopped treatment after one dose because of an acute infection and was reenrolled after recovery; each course was analyzed as a separate patient entry. Two patients had dose-limiting toxicity (reversible increases in serum creatinine or calculated serum creatinine clearance) at the 3.1 mg/m2 level. Probable or possible study drug-related grade 3 adverse events occurred in 6 (20.7%) patients [anemia (n = 2), decreased creatinine clearance, dyspnea, hyponatremia, and lymphopenia]. Ten (50%) of 20 response-evaluable patients had stable disease for four or more cycles. One patient with pancreatic adenocarcinoma had a partial response noted after 10 cycles, which was maintained for five additional cycles. The other patients achieving stable disease had one of the following: fibrosarcoma, chondrosarcoma, thymoma, atypical carcinoid of lung, or ovarian, testicular, breast (n = 2), and prostate cancer. The recommended phase II dose of LB-100 is 2.33 mg/m2 daily for 3 days every 3 weeks.Conclusions: The safety, tolerability, preliminary evidence of antitumor activity, and novel mechanism of action of LB-100 support its continued development alone and in combination with other therapies. Clin Cancer Res; 23(13); 3277-84. ©2016 AACR.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Neoplasias/tratamento farmacológico , Piperazinas/administração & dosagem , Proteína Fosfatase 2/antagonistas & inibidores , Adulto , Idoso , Compostos Bicíclicos Heterocíclicos com Pontes/efeitos adversos , Relação Dose-Resposta a Droga , Esquema de Medicação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias/genética , Neoplasias/patologia , Piperazinas/efeitos adversos , Proteína Fosfatase 2/genética
9.
Environ Res ; 111(5): 702-7, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21507392

RESUMO

BACKGROUND: Cadmium is a ubiquitous environmental pollutant associated with increased risk of leading causes of mortality and morbidity in women, including breast cancer and osteoporosis. Iron deficiency increases absorption of dietary cadmium, rendering women, who tend to have lower iron stores than men, more susceptible to cadmium uptake. We used body iron, a measure that incorporates both serum ferritin and soluble transferrin receptor, as recommended by the World Health Organization, to evaluate the relationships between iron status and urine and blood cadmium. METHODS: Serum ferritin, soluble transferrin receptor, urine and blood cadmium values in never-smoking, non-pregnant, non-lactating, non-menopausal women aged 20-49 years (n=599) were obtained from the 2003-2008 National Health and Nutrition Examination Surveys. Body iron was calculated from serum ferritin and soluble transferrin receptor, and iron deficiency defined as body iron <0 mg/kg. Robust linear regression was used to evaluate the relationships between body iron and blood and urine cadmium, adjusted for age, race, poverty, body mass index, and parity. RESULTS: Per incremental (mg/kg) increase in body iron, urine cadmium decreased by 0.003 µg/g creatinine and blood cadmium decreased by 0.014 µg/L. Iron deficiency was associated with 0.044 µg/g creatinine greater urine cadmium (95% CI=0.020, 0.069) and 0.162 µg/L greater blood cadmium (95% CI=0.132, 0.193). CONCLUSIONS: Iron deficiency is a risk factor for increased blood and urine cadmium among never-smoking, pre-menopausal, non-pregnant US women, independent of age, race, poverty, body mass index and parity. Expanding programs to detect and correct iron deficiency among non-pregnant women merits consideration as a potential means to reduce the risk of cadmium associated diseases.


Assuntos
Cádmio/metabolismo , Exposição Ambiental/estatística & dados numéricos , Poluentes Ambientais/metabolismo , Ferro/metabolismo , Adulto , Anemia Ferropriva/sangue , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/urina , Cádmio/sangue , Cádmio/urina , Poluentes Ambientais/sangue , Poluentes Ambientais/urina , Feminino , Ferritinas/sangue , Humanos , Pessoa de Meia-Idade , Fumar/epidemiologia , Transferrina/metabolismo , Estados Unidos/epidemiologia , Adulto Jovem
10.
Aging (Albany NY) ; 2(11): 804-14, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21071816

RESUMO

Breast cancer is the most prevalent women's cancer, with an age-adjusted incidence of 122.9 per 100,000 US women. Cadmium, a ubiquitous carcinogenic pollutant with multiple biological effects, has been reported to be associated with breast cancer in one US regional case-control study. We examined the association of breast cancer with urinary cadmium (UCd), in a case-control sample of women living on Long Island (LI), NY (100 with breast cancer and 98 without), a region with an especially high rate of breast cancer (142.7 per 100,000 in Suffolk County) and in a representative sample of US women (NHANES 1999-2008, 92 with breast cancer and 2,884 without). In a multivariable logistic model, both samples showed a significant trend for increased odds of breast cancer across increasing UCd quartiles (NHANES, p=0.039 and LI, p=0.023). Compared to those in the lowest quartile, LI women in the highest quartile had increased risk for breast cancer (OR=2.69; 95% CI=1.07, 6.78) and US women in the two highest quartiles had increased risk (OR=2.50; 95% CI=1.11, 5.63 and OR=2.22; 95% CI=.89, 5.52, respectively). Further research is warranted on the impact of environmental cadmium on breast cancer risk in specific populations and on identifying the underlying molecular mechanisms.


Assuntos
Neoplasias da Mama/etiologia , Cádmio/efeitos adversos , Poluentes Ambientais/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/urina , Cádmio/urina , Estudos de Casos e Controles , Exposição Ambiental , Poluentes Ambientais/urina , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , New York/epidemiologia , Medição de Risco , Fatores de Risco
11.
Environ Res ; 110(1): 105-11, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19875111

RESUMO

BACKGROUND: Increased body burden of environmental cadmium has been associated with greater risk of decreased bone mineral density (BMD) and osteoporosis in middle-aged and older women, and an inverse relationship has been reported between follicle-stimulating hormone (FSH) and BMD in middle-aged women; however, the relationships between cadmium and FSH are uncertain, and the associations of each with bone loss have not been analyzed in a single population. OBJECTIVES: The objective of this study was to evaluate the associations between creatinine-adjusted urinary cadmium (UCd) and FSH levels, and the associations between UCd and FSH with BMD and osteoporosis, in postmenopausal and perimenopausal women aged 42-60 years. METHODS: Data were obtained from the Third National Health Examination and Nutrition Survey, 1988-1994 (NHANES III). Outcomes evaluated were serum FSH levels, femoral bone mineral density measured by dual energy X-ray absorptiometry, and osteoporosis indicated by femoral BMD cutoffs based on the international standard. Urinary cadmium levels were analyzed for association with these outcomes, and FSH levels analyzed for association with bone effects, using multiple regression. Subset analysis was conducted by a dichotomous measure of body mass index (BMI) to proxy higher and lower adipose-synthesized estrogen effects. RESULTS: UCd was associated with increased serum FSH in perimenopausal women with high BMI (n=642; beta=0.45; p< or =0.05; R(2)=0.35) and low BMI (n=408; beta=0.61; p< or =0.01; R(2)=0.34). Among perimenopausal women with high BMI, BMD was inversely related to UCd (beta=-0.04; p< or =0.05) and FSH (beta=-0.03; p< or =0.05). In postmenopausal women with low BMI, an incremental increase in FSH was associated with 2.78 greater odds for osteoporosis (109 with and 706 without) (OR=2.78; 95% CI=1.43, 5.42; p< or =0.01). CONCLUSION: Long-term cadmium exposure at environmental levels is associated with increased serum FSH, and both FSH and UCd are associated with bone loss, in US women aged 42-60 years.


Assuntos
Densidade Óssea , Cádmio/urina , Poluentes Ambientais/urina , Hormônio Foliculoestimulante/sangue , Inquéritos Epidemiológicos , Osteoporose Pós-Menopausa/induzido quimicamente , Absorciometria de Fóton , Adulto , Carga Corporal (Radioterapia) , Índice de Massa Corporal , Densidade Óssea/efeitos dos fármacos , Cádmio/toxicidade , Creatinina/urina , Estudos Transversais , Poluentes Ambientais/toxicidade , Feminino , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/sangue , Osteoporose Pós-Menopausa/urina , Estados Unidos
12.
Cell Cycle ; 8(20): 3303-6, 2009 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19806030

RESUMO

Despite improvements in the therapeutic efficacy of rationally designed cancer treatment regimens, most cancers remain incurable once spread beyond their sites of origin. Failure to achieve sustained control or eradication of cancers arises in large part because a subpopulation of quiescent "cancer stem cells" is insensitive to drugs targeting cell growth and replication and because defense mechanisms critical to survival of the normal cell also protect the cancer cell from cytotoxic injury. Global alteration of signal transduction by inhibition of serine/threonine dephosphorylation has recently been shown to markedly potentiate cancer cell killing by the DNA-methylating drug, temozolomide. Inhibition of the multifunctional protein phosphatase 2A appears to drive quiescent cancer cells into cycle and simultaneously inhibits cycle arrest, permitting cancer cell entry into mitosis despite the presence of chemotherapy induced DNA-damage. Absence of toxicity in animal models suggests that multi-site mutations in pathways regulating cell cycle in cancer cells make them more vulnerable than normal cells to large changes in the balance of phosphorylation-regulated signaling. Global modulation of the serine-threonine phospho-proteome may be a general method for enhancing the effectiveness of cytotoxic cancer therapy.


Assuntos
Ciclo Celular , Dano ao DNA , Neoplasias/tratamento farmacológico , Proteína Fosfatase 2/metabolismo , Animais , Antineoplásicos Alquilantes/farmacologia , Quebras de DNA de Cadeia Dupla , Dacarbazina/análogos & derivados , Dacarbazina/farmacologia , Camundongos , Fosforilação , Proteína Fosfatase 2/antagonistas & inibidores , Proteoma , Transdução de Sinais , Temozolomida , Proteína Supressora de Tumor p53/metabolismo
13.
Proc Natl Acad Sci U S A ; 106(28): 11697-702, 2009 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-19564615

RESUMO

A variety of mechanisms maintain the integrity of the genome in the face of cell stress. Cancer cell response to chemotherapeutic and radiation-induced DNA damage is mediated by multiple defense mechanisms including polo-like kinase 1 (Plk-1), protein kinase B (Akt-1), and/or p53 pathways leading to either apoptosis or cell cycle arrest. Subsequently, a subpopulation of arrested viable cancer cells may remain and recur despite aggressive and repetitive therapy. Here, we show that modulation (activation of Akt-1 and Plk-1 and repression of p53) of these pathways simultaneously results in paradoxical enhancement of the effectiveness of cytotoxic chemotherapy. We demonstrate that a small molecule inhibitor, LB-1.2, of protein phosphatase 2A (PP2A) activates Plk-1 and Akt-1 and decreases p53 abundance in tumor cells. Combined with temozolomide (TMZ; a DNA-methylating chemotherapeutic drug), LB-1.2 causes complete regression of glioblastoma multiforme (GBM) xenografts without recurrence in 50% of animals (up to 28 weeks) and complete inhibition of growth of neuroblastoma (NB) xenografts. Treatment with either drug alone results in only short-term inhibition/regression with all xenografts resuming rapid growth. Combined with another widely used anticancer drug, Doxorubicin (DOX, a DNA intercalating agent), LB-1.2 also causes marked GBM xenograft regression, whereas DOX alone only slows growth. Inhibition of PP2A by LB-1.2 blocks cell-cycle arrest and increases progression of cell cycle in the presence of TMZ or DOX. Pharmacologic inhibition of PP2A may be a general method for enhancing the effectiveness of cancer treatments that damage DNA or disrupt components of cell replication.


Assuntos
Dano ao DNA , Inibidores Enzimáticos/uso terapêutico , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/tratamento farmacológico , Neuroblastoma/tratamento farmacológico , Proteína Fosfatase 2/antagonistas & inibidores , Animais , Antineoplásicos Alquilantes/uso terapêutico , Western Blotting , Proteínas de Ciclo Celular/metabolismo , Dacarbazina/análogos & derivados , Dacarbazina/uso terapêutico , Inibidores Enzimáticos/farmacologia , Citometria de Fluxo , Imunofluorescência , Camundongos , Camundongos SCID , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Temozolomida , Quinase 1 Polo-Like
14.
Environ Health Perspect ; 116(10): 1338-43, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18941575

RESUMO

BACKGROUND: Urinary cadmium (U-Cd) has been associated with decreased peripheral bone mineral density (BMD) and osteoporosis. This association, however, has not been confirmed using femoral BMD, the international standard for diagnosing osteoporosis, at levels < 1.0 microg Cd/g creatinine. OBJECTIVES: Our goal was to investigate the statistical association between U-Cd, at levels or= 50 years of age. METHODS: We drew data from the National Health and Nutrition Examination Surveys for 1988-1994 (n = 3,207) and 1999-2004 (n = 1,051). Osteoporosis was indicated by hip BMD cutoffs based on the international standard and self-report of physician diagnosis. We analyzed U-Cd levels for association with osteoporosis using multiple logistic regression. RESULTS: Women >or= 50 years of age with U-Cd levels between 0.50 and 1.00 microg/g creatinine were at 43% greater risk for hip-BMD-defined osteoporosis, relative to those with levels or= 50 years of age.


Assuntos
Cádmio/urina , Osteoporose/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Creatinina/urina , Feminino , Humanos , Pessoa de Meia-Idade , Inquéritos Nutricionais , Osteoporose/urina , Análise de Regressão , Estados Unidos/epidemiologia
15.
Proc Natl Acad Sci U S A ; 100(25): 14666-71, 2003 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-14657331

RESUMO

We propose a comprehensive pattern recognition procedure that will achieve best discrimination between two or more sets of subjects with data in the same coordinate system. Applying the procedure to MS data of proteomic analysis of serum from ovarian cancer patients and serum from cancer-free individuals in the Food and Drug Administration/National Cancer Institute Clinical Proteomics Database, we have achieved perfect discrimination (100% sensitivity, 100% specificity) of patients with ovarian cancer, including early-stage disease, from normal controls for two independent sets of data. Our procedure identifies the best subset of proteomic biomarkers for optimal discrimination between the groups and appears to have higher discriminatory power than other methods reported to date. For large-scale screening for diseases of relatively low prevalence such as ovarian cancer, almost perfect specificity and sensitivity of the detection system is critical to avoid unmanageably high numbers of false-positive cases.


Assuntos
Biomarcadores Tumorais/sangue , Espectrometria de Massas/métodos , Neoplasias/diagnóstico , Neoplasias/genética , Algoritmos , Bases de Dados como Assunto , Feminino , Humanos , Internet , Neoplasias Ovarianas/metabolismo , Valor Preditivo dos Testes , Proteoma , Sensibilidade e Especificidade
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