RESUMO
BACKGROUND: Blacks/African American (BAA) patients diagnosed with head and neck squamous cell carcinoma (HNSCC) have worse survival outcomes than White patients. However, the mechanisms underlying racial disparities in HNSCC have not been thoroughly characterized. METHODS: Data on gene expression, copy number variants (CNVs), gene mutations, and methylation were obtained from 6 head and neck cancer datasets. Comparative bioinformatics analysis of the above genomic features was performed between BAAs and Whites. The expression pattern of GSTM1 was validated by immunohistochemistry using tumor tissue microarray (TMA). Effect of GSTM1 knockdown were assessed by cell proliferation, colony formation, and tumor development in an orthotopic mouse model. The changes in protein kinases were determined using the Proteome Profiler Human Phospho-Kinase Array Kit in HNSCC cells with or without GSTM1 knockdown. RESULTS: We identified ancestry-related differential genomic profiles in HNSCC. Specifically, in BAA HNSCC, FAT1 mutations were associated with its gene expression, SALL3 gene expression correlated with its gene CNVs, and RTP4 gene expression showed an inverse correlation with its methylation. Notably, GSTM1 emerged as a prognostic risk factor for BAA HNSCC, with high gene CNVs and expression levels correlating with poor overall survival in BAA patients. Immunohistochemistry results from newly developed in-house TMA validated the expression pattern of GSTM1 between BAA HNSCC and White HNSCC. In an orthotopic mouse model, GSTM1 knockdown significantly inhibited malignant progression in tumors derived from BAAs. In contrast, loss of GSTM1 did not affect the development of HNSCC originating in Whites. Mechanistically, GSTM1 knockdown suppressed HSP27 phosphorylation and ß-catenin in BAA HNSCC cells, but not in White HNSCC cells. This differential effect at least partially contributes to tumor development in BAA patients. CONCLUSION: This study identifies GSTM1 as a novel molecular determinant of survival in HNSCC patients of African descent. It also provides a molecular basis for future research focused on identifying molecular determinants and developing therapeutic interventions to improve outcomes for BAA patients with HNSCC.
Assuntos
Glutationa Transferase , Neoplasias de Cabeça e Pescoço , Animais , Feminino , Humanos , Masculino , Camundongos , Biomarcadores Tumorais/genética , Negro ou Afro-Americano/genética , Linhagem Celular Tumoral , Variações do Número de Cópias de DNA , Glutationa Transferase/genética , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/mortalidade , Prognóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/mortalidade , Brancos/genéticaRESUMO
Anti-programmed cell death protein 1 (PD-1) therapy is a standard of care in recurrent metastatic head and neck squamous cell carcinoma (RMHNSCC). Vascular endothelial growth factor inhibitors, including tyrosine kinase inhibitors, have immunomodulatory properties and have offered promising results when combined with anti-PD-1 agents. We conducted a phase 2, multicenter, single-arm trial of pembrolizumab and cabozantinib in patients with RMHNSCC who had Response Evaluation Criteria in Solid Tumors v.1.1 measurable disease and no contraindications to either agent. We assessed the primary end points of tolerability and overall response rate to the combination with secondary end points of progression-free survival and overall survival and performed correlative studies with PDL-1 and combined positive score, CD8+ T cell infiltration and tumor mutational burden. A total of 50 patients were screened and 36 were enrolled with 33 evaluable for response. The primary end point was met, with 17 out of 33 patients having a partial response (52%) and 13 (39%) stable disease with an overall clinical benefit rate of 91%. Median and 1-year overall survival were 22.3 months (95% confidence interval (CI) = 11.7-32.9) and 68.4% (95% CI = 45.1%-83.5%), respectively. Median and 1-year progression-free survival were 14.6 months (95% CI = 8.2-19.6) and 54% (95% CI = 31.5%-72%), respectively. Grade 3 or higher treatment-related adverse events included increased aspartate aminotransferase (n = 2, 5.6%). In 16 patients (44.4%), the dose of cabozantinib was reduced to 20 mg daily. The overall response rate correlated positively with baseline CD8+ T cell infiltration. There was no observed correlation between tumor mutational burden and clinical outcome. Pembrolizumab and cabozantinib were well tolerated and showed promising clinical activity in patients with RMHNSCC. Further investigation of similar combinations are needed in RMHNSCC. The trial is registered at ClinicalTrials.gov under registration no. NCT03468218 .
Assuntos
Neoplasias de Cabeça e Pescoço , Fator A de Crescimento do Endotélio Vascular , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/tratamento farmacológicoRESUMO
OBJECTIVES: The eighth edition American Joint Committee on Cancer (AJCC) Staging incorporates significant changes to the seventh edition in the staging of oropharyngeal squamous cell carcinomas (OPSCC). An important change was the inclusion of OPSCC associated with the human papilloma virus (HPV). Our goal is to compare the performance of both staging systems for patients with HPV-selected and unselected clinical characteristics for OPSCC. METHODS: Using the Surveillance, Epidemiology, and End Results (SEER) database, 2004-2016, we identified patients with likely HPV-associated OPSCC based on surrogate markers (white males aged <65 years old with squamous cell carcinomas of the tonsil and base of tongue), excluding those who underwent surgery. We re-classified these patients using seventh and eighth edition staging for HPV-selected OPSCC and compared the prediction performance of both staging editions for overall survival (OS) and disease-specific survival (DSS). We performed the same analysis for clinically unselected patients with OPSCC. RESULTS: Our analysis included 9554 patients with a median follow-up of 67 months. Comparing the eighth versus seventh edition for our HPV-selected cohort, clinical staging changed for 92.3% of patients and 10-year OS was 62.2%, 61.2%, 35.3%, and 15.5% for Stage I, II, III, and IV, versus 52.9%, 59.2%, 61.6%, 55.1%, 38.3%, and 15.5% for stage I, II, III, IVA, IVB, and IVC, respectively. A similar pattern was observed for 10-year DSS. The concordance statistics for our HPV-selected cohort were improved for both AJCC 7 (0.6260) and AJCC 8 (0.6846) compared with the unselected cohort, 0.5860 and 0.6457 for AJCC 7 and 8, respectively. CONCLUSION: The overall performance of discrimination improved from AJCC 7 to AJCC 8 for both clinically selected and unselected patients, but more notably for our HPV-selected cohort. Despite the lack of statistically significant differentiation between Stages I and II in AJCC 8 in either groups, markedly improved discrimination was observed between Stages I/II, III, and IV in the HPV-selected cohort.
Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Orofaríngeas , Infecções por Papillomavirus , Idoso , Carcinoma de Células Escamosas/patologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/patologia , Papillomaviridae , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/patologia , Prognóstico , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologiaRESUMO
Agonists of glucocorticoid receptor (GR) are frequently given to cancer patients with platinum-containing chemotherapy to reduce inflammation, but how GR influences tumor growth in response to platinum-based chemotherapy such as cisplatin through inflammation-independent signaling remains largely unclear. Combined genomics and transcription factor profiling reveal that MAST1, a critical platinum resistance factor that reprograms the MAPK pathway, is upregulated upon cisplatin exposure through activated transcription factor GR. Mechanistically, cisplatin binds to C622 in GR and recruits GR to the nucleus for its activation, which induces MAST1 expression and consequently reactivates MEK signaling. GR nuclear translocation and MAST1 upregulation coordinately occur in patient tumors collected after platinum treatment, and align with patient treatment resistance. Co-treatment with dexamethasone and cisplatin restores cisplatin-resistant tumor growth, whereas addition of the MAST1 inhibitor lestaurtinib abrogates tumor growth while preserving the inhibitory effect of dexamethasone on inflammation in vivo. These findings not only provide insights into the underlying mechanism of GR in cisplatin resistance but also offer an effective alternative therapeutic strategy to improve the clinical outcome of patients receiving platinum-based chemotherapy with GR agonists.
Assuntos
Cisplatino/farmacologia , Proteínas Associadas aos Microtúbulos/metabolismo , Platina/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Glucocorticoides/efeitos dos fármacos , Receptores de Glucocorticoides/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Núcleo Celular , Sobrevivência Celular , Citocinas , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/genética , Receptores de Glucocorticoides/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PURPOSE: Human papillomavirus (HPV)-related squamous cell carcinomas of the head and neck (SCCHNs) tend to have a distinct prognosis. Socioeconomic and demographic factors associated with metastatic disease at presentation and diagnosis in patients with HPV-related SCCHN tumors were examined. METHODS: The National Cancer Database (NCDB) was queried to assess patients with HPV-related oropharyngeal carcinomas (HPVOPCAs) and HPV-related nonoropharyngeal carcinomas (HPVNOPCAs) diagnosed between 2010 and 2014. Rate of metastases at presentation was analyzed using clinical M stage. Multivariable analysis was performed evaluating race, ethnicity, sex, age, facility location, facility type, insurance status, income, education, and tumor and nodal stage using logistic regression. RESULTS: A total of 12,857 patients with HPVOPCA and 952 patients with HPVNOPCA were included. Private insurance was carried by 64% and 47% of patients with HPVOPCA and HPVNOPCA, respectively. HPVOPCA was located in the tonsil in 56% of patients. For both HPVOPCA and HPVNOPCA, there was no meaningful difference in distant metastasis at presentation based on facility type or location, sex, race, Hispanic ethnicity, or urban or rural location. For HPVOPCA, there were significantly lower odds of metastasis in privately insured patients compared with uninsured patients (odds ratio [OR], 0.37; 95% CI, 0.21 to 0.64; P < .001) and higher odds of metastasis for patients living in census tracts with the lowest rates of high school graduates compared with the highest rates (OR, 1.81; 95% CI, 1.02 to 3.19; P = .041) and for patients with higher tumor stage (OR, 3.67, 95% CI, 2.25 to 5.99; P < .001) and nodal stage (OR, 3.34; 95% CI, 2.11 to 5.29; P < .001). For HPVNOPCA, neither higher T or N stage nor any demographic features were found to be associated with metastasis at presentation. CONCLUSION: This large retrospective analysis identifies likely modifiable risk factors for metastatic presentation in HPVOPCA. Educational interventions may result in modifications of these patterns.
Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Infecções por Papillomavirus , Etnicidade , Neoplasias de Cabeça e Pescoço/epidemiologia , Humanos , Infecções por Papillomavirus/epidemiologia , Estudos Retrospectivos , Fatores Socioeconômicos , Carcinoma de Células Escamosas de Cabeça e Pescoço/epidemiologiaRESUMO
How altered metabolism contributes to chemotherapy resistance in cancer cells remains unclear. Through a metabolism-related kinome RNAi screen, we identified inositol-trisphosphate 3-kinase B (ITPKB) as a critical enzyme that contributes to cisplatin-resistant tumor growth. We demonstrated that inositol 1,3,4,5-tetrakisphosphate (IP4), the product of ITPKB, plays a critical role in redox homeostasis upon cisplatin exposure by reducing cisplatin-induced ROS through inhibition of a ROS-generating enzyme, NADPH oxidase 4 (NOX4), which promotes cisplatin-resistant tumor growth. Mechanistically, we identified that IP4 competes with the NOX4 cofactor NADPH for binding and consequently inhibits NOX4. Targeting ITPKB with shRNA or its small-molecule inhibitor resulted in attenuation of NOX4 activity, imbalanced redox status, and sensitized cancer cells to cisplatin treatment in patient-derived xenografts. Our findings provide insight into the crosstalk between kinase-mediated metabolic regulation and platinum-based chemotherapy resistance in human cancers. Our study also suggests a distinctive signaling function of IP4 that regulates NOX4. Furthermore, pharmaceutical inhibition of ITPKB displayed synergistic attenuation of tumor growth with cisplatin, suggesting ITPKB as a promising synthetic lethal target for cancer therapeutic intervention to overcome cisplatin resistance.
Assuntos
Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , NADPH Oxidase 4/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/enzimologia , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Transdução de Sinais , Células A549 , Animais , Feminino , Humanos , Camundongos , Camundongos Nus , NADPH Oxidase 4/genética , Proteínas de Neoplasias/genética , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Oxirredução/efeitos dos fármacos , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Platinum-based chemotherapeutics represent a mainstay of cancer therapy, but resistance limits their curative potential. Through a kinome RNAi screen, we identified microtubule-associated serine/threonine kinase 1 (MAST1) as a main driver of cisplatin resistance in human cancers. Mechanistically, cisplatin but no other DNA-damaging agents inhibit the MAPK pathway by dissociating cRaf from MEK1, while MAST1 replaces cRaf to reactivate the MAPK pathway in a cRaf-independent manner. We show clinical evidence that expression of MAST1, both initial and cisplatin-induced, contributes to platinum resistance and worse clinical outcome. Targeting MAST1 with lestaurtinib, a recently identified MAST1 inhibitor, restores cisplatin sensitivity, leading to the synergistic attenuation of cancer cell proliferation and tumor growth in human cancer cells and patient-derived xenograft models.
Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , MAP Quinase Quinase 1/fisiologia , Proteínas Associadas aos Microtúbulos/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Proto-Oncogênicas c-raf/fisiologia , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Ativação Enzimática , Feminino , Humanos , CamundongosRESUMO
Human papillomavirus (HPV) is the causative agent of a subgroup of head and neck cancer characterized by an intrinsic radiosensitivity. HPV initiates cellular transformation through the activity of E6 and E7 proteins. E6 and E7 expression is necessary but not sufficient to transform the host cell, as genomic instability is required to acquire the malignant phenotype in HPV-initiated cells. This study reveals a key role played by oxidative stress in promoting genomic instability and radiosensitivity in HPV-positive head and neck cancer. By employing an isogenic human cell model, we observed that expression of E6 and E7 is sufficient to induce reactive oxygen species (ROS) generation in head and neck cancer cells. E6/E7-induced oxidative stress is mediated by nicotinamide adenine dinucleotide phosphate oxidases (NOXs) and causes DNA damage and chromosomal aberrations. This mechanism for genomic instability distinguishes HPV-positive from HPV-negative tumors, as we observed NOX-induced oxidative stress in HPV-positive but not HPV-negative head and neck cancer cells. We identified NOX2 as the source of HPV-induced oxidative stress as NOX2 silencing significantly reduced ROS generation, DNA damage and chromosomal aberrations in HPV-positive cells. Due to their state of chronic oxidative stress, HPV-positive cells are more susceptible to DNA damage induced by ROS and ionizing radiation (IR). Furthermore, exposure to IR results in the formation of complex lesions in HPV-positive cells as indicated by the higher amount of chromosomal breakage observed in this group of cells. These results reveal a novel mechanism for sustaining genomic instability in HPV-positive head and neck tumors and elucidate its contribution to their intrinsic radiosensitivity.
Assuntos
Dano ao DNA , Neoplasias de Cabeça e Pescoço/virologia , Glicoproteínas de Membrana/fisiologia , NADPH Oxidases/fisiologia , Proteínas Oncogênicas Virais/fisiologia , Estresse Oxidativo , Proteínas E7 de Papillomavirus/fisiologia , Proteínas Repressoras/fisiologia , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Suscetibilidade a Doenças , Instabilidade Genômica , Neoplasias de Cabeça e Pescoço/genética , Humanos , NADPH Oxidase 2 , Espécies Reativas de Oxigênio/metabolismoRESUMO
How oncogenic signalling coordinates glycolysis and anabolic biosynthesis in cancer cells remains unclear. We recently reported that the glycolytic enzyme phosphoglycerate mutase 1 (PGAM1) regulates anabolic biosynthesis by controlling intracellular levels of its substrate 3-phosphoglycerate and product 2-phosphoglycerate. Here we report a novel mechanism in which Y26 phosphorylation enhances PGAM1 activation through release of inhibitory E19 that blocks the active site, stabilising cofactor 2,3-bisphosphoglycerate binding and H11 phosphorylation. We also report the crystal structure of H11-phosphorylated PGAM1 and find that phospho-H11 activates PGAM1 at least in part by promoting substrate 3-phosphoglycerate binding. Moreover, Y26 phosphorylation of PGAM1 is common in human cancer cells and contributes to regulation of 3-phosphoglycerate and 2-phosphoglycerate levels, promoting cancer cell proliferation and tumour growth. As PGAM1 is a negative transcriptional target of TP53, and is therefore commonly upregulated in human cancers, these findings suggest that Y26 phosphorylation represents an additional acute mechanism underlying phosphoglycerate mutase 1 upregulation.
Assuntos
Neoplasias/enzimologia , Neoplasias/metabolismo , Fosfoglicerato Mutase/química , Fosfoglicerato Mutase/metabolismo , Fosfotirosina/metabolismo , 2,3-Difosfoglicerato/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Proliferação de Células , Estabilidade Enzimática , Ácidos Glicéricos/metabolismo , Glicólise , Histidina/metabolismo , Humanos , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Neoplasias/patologia , FosforilaçãoRESUMO
It is unclear how cancer cells coordinate glycolysis and biosynthesis to support rapidly growing tumors. We found that the glycolytic enzyme phosphoglycerate mutase 1 (PGAM1), commonly upregulated in human cancers due to loss of TP53, contributes to biosynthesis regulation in part by controlling intracellular levels of its substrate, 3-phosphoglycerate (3-PG), and product, 2-phosphoglycerate (2-PG). 3-PG binds to and inhibits 6-phosphogluconate dehydrogenase in the oxidative pentose phosphate pathway (PPP), while 2-PG activates 3-phosphoglycerate dehydrogenase to provide feedback control of 3-PG levels. Inhibition of PGAM1 by shRNA or a small molecule inhibitor PGMI-004A results in increased 3-PG and decreased 2-PG levels in cancer cells, leading to significantly decreased glycolysis, PPP flux and biosynthesis, as well as attenuated cell proliferation and tumor growth.
Assuntos
Glicólise/fisiologia , Neoplasias/enzimologia , Fosfoglicerato Mutase/fisiologia , Animais , Ligação Competitiva , Linhagem Celular Tumoral , Proliferação de Células , Ativação Enzimática , Técnicas de Silenciamento de Genes , Gluconatos/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Ácidos Glicéricos/metabolismo , Glicólise/genética , Humanos , Camundongos , Camundongos Nus , Modelos Moleculares , Neoplasias/patologia , Fosfoglicerato Mutase/antagonistas & inibidores , Fosfoglicerato Mutase/genética , Fosfoglicerato Mutase/metabolismoRESUMO
Hyperspectral imaging (HSI) is an emerging modality for various medical applications. Its spectroscopic data might be able to be used to noninvasively detect cancer. Quantitative analysis is often necessary in order to differentiate healthy from diseased tissue. We propose the use of an advanced image processing and classification method in order to analyze hyperspectral image data for prostate cancer detection. The spectral signatures were extracted and evaluated in both cancerous and normal tissue. Least squares support vector machines were developed and evaluated for classifying hyperspectral data in order to enhance the detection of cancer tissue. This method was used to detect prostate cancer in tumor-bearing mice and on pathology slides. Spatially resolved images were created to highlight the differences of the reflectance properties of cancer versus those of normal tissue. Preliminary results with 11 mice showed that the sensitivity and specificity of the hyperspectral image classification method are 92.8% to 2.0% and 96.9% to 1.3%, respectively. Therefore, this imaging method may be able to help physicians to dissect malignant regions with a safe margin and to evaluate the tumor bed after resection. This pilot study may lead to advances in the optical diagnosis of prostate cancer using HSI technology.
Assuntos
Algoritmos , Interpretação de Imagem Assistida por Computador/métodos , Imagem Óptica/métodos , Reconhecimento Automatizado de Padrão/métodos , Neoplasias da Próstata/patologia , Análise Espectral/métodos , Animais , Inteligência Artificial , Linhagem Celular Tumoral , Aumento da Imagem/métodos , Masculino , Camundongos , Camundongos Nus , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The role of Rab coupling protein (RCP) has not been previously investigated in squamous cell carcinoma of the head and neck (SCCHN). The aim of this study was to explore RCP protein expression and its clinicopathological significance in SCCHN. RCP protein expression in 95 SCCHN samples, 18 vocal nodule epithelia and 16 leukoplakia epithelia samples was analyzed by immunohistochemistry and correlated with clinicopathological parameters and patient outcome. Our data indicated that vocal nodule epithelia, leukoplakia epithelia and SCCHN showed a gradual increase in the expression of RCP protein. RCP overexpression was significantly associated with T classification, clinical staging, lymph node metastasis and recurrence. Survival analysis revealed that a high RCP expression was significantly correlated with shorter overall survival and disease-free survival. In conclusion, RCP protein may contribute to the malignant progression of SCCHN, and serves as a novel prognostic marker in patients with SCCHN.
RESUMO
The present study was to identify and quantitate differentially expressed proteins in laryngeal squamous cell carcinoma (LSCC) tissues with or without lymph node metastasis and to explore transcriptional factors and regulation networks associated with the process. Tissue specimens were taken from 20 patients with LSCC, including 10 cases of LSCC without metastasis LSCC (N0) and 10 cases of LSCC with metastasis LSCC (Nx). Among the 643 unique proteins identified by using iTRAQ labeling and quantitative proteomic technology, 389 proteins showed an abundance change in LSCC (Nx) as compared to LSCC (N0). Cytoskeleton remodeling, cell adhesion, and immune response activation were found to be the main processes in LSCC metastasis. The construction of transcription regulation networks identified key transcription regulators for lymph node metastasis of LSCC, including Sp1, c-myc, and p53, which may affect LSCC metastasis through the epithelial-mesenchymal transition. Furthermore, our results suggest that ubiquitination may be a critical factor in the networks. The present study provides insights into transcriptional factors and regulation networks involved in LSCC metastasis, which may lead to new strategies for treatment of LSCC metastasis.
Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias Laríngeas/metabolismo , Fatores de Transcrição/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Adesão Celular , Citoesqueleto/metabolismo , Regulação para Baixo , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Neoplasias Laríngeas/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Mapas de Interação de Proteínas , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fator de Transcrição Sp1/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço , Proteína Supressora de Tumor p53/metabolismo , Regulação para CimaRESUMO
Many tumor cells rely on aerobic glycolysis instead of oxidative phosphorylation for their continued proliferation and survival. Myc and HIF-1 are believed to promote such a metabolic switch by, in part, upregulating gene expression of pyruvate dehydrogenase (PDH) kinase 1 (PDHK1), which phosphorylates and inactivates mitochondrial PDH and consequently pyruvate dehydrogenase complex (PDC). Here we report that tyrosine phosphorylation enhances PDHK1 kinase activity by promoting ATP and PDC binding. Functional PDC can form in mitochondria outside of the matrix in some cancer cells and PDHK1 is commonly tyrosine phosphorylated in human cancers by diverse oncogenic tyrosine kinases localized to different mitochondrial compartments. Expression of phosphorylation-deficient, catalytic hypomorph PDHK1 mutants in cancer cells leads to decreased cell proliferation under hypoxia and increased oxidative phosphorylation with enhanced mitochondrial utilization of pyruvate and reduced tumor growth in xenograft nude mice. Together, tyrosine phosphorylation activates PDHK1 to promote the Warburg effect and tumor growth.
Assuntos
Mitocôndrias/enzimologia , Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Tirosina/metabolismo , Animais , Feminino , Camundongos , Camundongos Nus , Mitocôndrias/metabolismo , Transplante de Neoplasias , Neoplasias/patologia , Fosforilação , Piruvato Desidrogenase Quinase de Transferência de Acetil , Transplante HeterólogoRESUMO
The Warburg effect describes an increase in aerobic glycolysis and enhanced lactate production in cancer cells. Lactate dehydrogenase A (LDH-A) regulates the last step of glycolysis that generates lactate and permits the regeneration of NAD(+). LDH-A gene expression is believed to be upregulated by both HIF and Myc in cancer cells to achieve increased lactate production. However, how oncogenic signals activate LDH-A to regulate cancer cell metabolism remains unclear. We found that the oncogenic receptor tyrosine kinase FGFR1 directly phosphorylates LDH-A. Phosphorylation at Y10 and Y83 enhances LDH-A activity by enhancing the formation of active, tetrameric LDH-A and the binding of LDH-A substrate NADH, respectively. Moreover, Y10 phosphorylation of LDH-A is common in diverse human cancer cells, which correlates with activation of multiple oncogenic tyrosine kinases. Interestingly, cancer cells with stable knockdown of endogenous LDH-A and rescue expression of a catalytic hypomorph LDH-A mutant, Y10F, demonstrate increased respiration through mitochondrial complex I to sustain glycolysis by providing NAD(+). However, such a compensatory increase in mitochondrial respiration in Y10F cells is insufficient to fully sustain glycolysis. Y10 rescue cells show decreased cell proliferation and ATP levels under hypoxia and reduced tumor growth in xenograft nude mice. Our findings suggest that tyrosine phosphorylation enhances LDH-A enzyme activity to promote the Warburg effect and tumor growth by regulating the NADH/NAD(+) redox homeostasis, representing an acute molecular mechanism underlying the enhanced lactate production in cancer cells.
Assuntos
Homeostase , L-Lactato Desidrogenase/metabolismo , NAD/metabolismo , Tirosina/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Respiração Celular , Glicólise , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , L-Lactato Desidrogenase/genética , Lactato Desidrogenase 5 , Ácido Láctico/biossíntese , Camundongos , Camundongos Nus , Mitocôndrias/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Oxirredução , Fosforilação , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismoRESUMO
BACKGROUND: Perifosine, an alkylphospholipid tested in phase II clinical trials, modulates the extrinsic apoptotic pathway and cooperates with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to augment apoptosis. The current study focuses on revealing the mechanisms by which perifosine enhances TRAIL-induced apoptosis. RESULTS: The combination of perifosine and TRAIL was more active than each single agent alone in inducing apoptosis of head and neck squamous cell carcinoma cells and inhibiting the growth of xenografts. Interestingly, perifosine primarily increased cell surface levels of DR5 although it elevated the expression of both DR4 and DR5. Blockade of DR5, but not DR4 upregulation, via small interfering RNA (siRNA) inhibited perifosine/TRAIL-induced apoptosis. Perifosine increased phosphorylated c-Jun NH2-terminal kinase (JNK) and c-Jun levels, which were paralleled with DR4 and DR5 induction. However, only DR5 upregulaiton induced by perifosine could be abrogated by both the JNK inhibitor SP600125 and JNK siRNA. The antioxidants, N-acetylcysteine and glutathione, but not vitamin C or tiron, inhibited perifosine-induced elevation of p-c-Jun, DR4 and DR5. Moreover, no increased production of reactive oxygen species was detected in perifosine-treated cells although reduced levels of intracellular GSH were measured. CONCLUSIONS: DR5 induction plays a critical role in mediating perifosine/TRAIL-induced apoptosis. Perifosine induces DR5 expression through a JNK-dependent mechanism independent of reactive oxygen species.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Fosforilcolina/análogos & derivados , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Animais , Antracenos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/genética , Western Blotting , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/genética , Glutationa/metabolismo , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Camundongos , Camundongos Nus , Fosforilcolina/farmacologia , Fosforilcolina/uso terapêutico , RNA Interferente Pequeno , Espécies Reativas de Oxigênio/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Death receptor 5 (DR5) and caspase-8 are major components in the extrinsic apoptotic pathway. The alterations of the expression of these proteins during the metastasis of head and neck squamous cell carcinoma (HNSCC) and their prognostic impact have not been reported. The present study analyzes the expression of DR5 and caspase-8 by immunohistochemistry (IHC) in primary and metastatic HNSCCs and their impact on patient survival. Tumor samples in this study included 100 primary HNSCC with no evidence of metastasis, 100 primary HNSCC with lymph node metastasis (LNM) and 100 matching LNM. IHC analysis revealed a significant loss or downregulation of DR5 expression in primary tumors with metastasis and their matching LNM compared to primary tumors with no evidence of metastasis. A similar trend was observed in caspase-8 expression although it was not statistically significant. Downregulation of caspase-8 and DR5 expression was significantly correlated with poorly differentiated tumors compared to moderately and well differentiated tumors. Univariate analysis indicates that, in HNSCC with no metastasis, higher expression of caspase-8 significantly correlated with better disease-free survival and overall survival. However, in HNSCC with LNM, higher caspase-8 expression significantly correlated with poorer disease-free survival and overall survival. Similar results were also generated when we combined both DR5 and caspase-8. Taken together, we suggest that both DR5 and caspase-8 are involved in regulation of HNSCC metastasis. Our findings warrant further investigation on the dual role of caspase-8 in cancer development.
Assuntos
Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/patologia , Caspase 8/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/patologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Carcinoma de Células Escamosas/genética , Feminino , Neoplasias de Cabeça e Pescoço/genética , Humanos , Imuno-Histoquímica , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de SobrevidaRESUMO
The Warburg effect describes a pro-oncogenic metabolism switch such that cancer cells take up more glucose than normal tissue and favor incomplete oxidation of glucose even in the presence of oxygen. To better understand how tyrosine kinase signaling, which is commonly increased in tumors, regulates the Warburg effect, we performed phosphoproteomic studies. We found that oncogenic forms of fibroblast growth factor receptor type 1 inhibit the pyruvate kinase M2 (PKM2) isoform by direct phosphorylation of PKM2 tyrosine residue 105 (Y(105)). This inhibits the formation of active, tetrameric PKM2 by disrupting binding of the PKM2 cofactor fructose-1,6-bisphosphate. Furthermore, we found that phosphorylation of PKM2 Y(105) is common in human cancers. The presence of a PKM2 mutant in which phenylalanine is substituted for Y(105) (Y105F) in cancer cells leads to decreased cell proliferation under hypoxic conditions, increased oxidative phosphorylation with reduced lactate production, and reduced tumor growth in xenografts in nude mice. Our findings suggest that tyrosine phosphorylation regulates PKM2 to provide a metabolic advantage to tumor cells, thereby promoting tumor growth.
Assuntos
Glicólise/fisiologia , Neoplasias/metabolismo , Piruvato Quinase/metabolismo , Tirosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células , Frutosedifosfatos/metabolismo , Glucose/metabolismo , Humanos , Immunoblotting , Células K562 , Masculino , Camundongos , Camundongos Nus , Mutação , Neoplasias/genética , Neoplasias/patologia , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Consumo de Oxigênio , Fosforilação , Proteômica/métodos , Piruvato Quinase/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Transplante Heterólogo , Carga TumoralRESUMO
We describe biocompatible and nontoxic nanoparticles for in vivo tumor targeting and detection based on pegylated gold nanoparticles and surface-enhanced Raman scattering (SERS). Colloidal gold has been safely used to treat rheumatoid arthritis for 50 years, and has recently been found to amplify the efficiency of Raman scattering by 14-15 orders of magnitude. Here we show that large optical enhancements can be achieved under in vivo conditions for tumor detection in live animals. An important finding is that small-molecule Raman reporters such as organic dyes were not displaced but were stabilized by thiol-modified polyethylene glycols. These pegylated SERS nanoparticles were considerably brighter than semiconductor quantum dots with light emission in the near-infrared window. When conjugated to tumor-targeting ligands such as single-chain variable fragment (ScFv) antibodies, the conjugated nanoparticles were able to target tumor biomarkers such as epidermal growth factor receptors on human cancer cells and in xenograft tumor models.