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1.
Cell Cycle ; : 1-13, 2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33818291

RESUMO

Tau accumulation is a core component of Alzheimer's disease and other neurodegenerative tauopathies. While tau's impact on neurons is a major area of research, the effect of extracellular tau on astrocytes is largely unknown. This article summarizes our recent studies showing that astrocyte senescence plays a critical role in neurodegenerative diseases and integrates extracellular tau into the regulatory loop of senescent astrocyte-mediated neurotoxicity. Human astrocytes in vitro undergoing senescence were shown to acquire the inflammatory senescence-associated secretory phenotype (SASP) and toxicity to neurons, which may recapitulate aging- and disease-associated neurodegeneration. Here, we show that human astrocytes exposed to extracellular tau in vitro also undergo cellular senescence and acquire a neurotoxic SASP (e.g. IL-6 secretion), with oxidative stress response (indicated by upregulated NRF2 target genes) and a possible activation of inflammasome (indicated by upregulated ASC and IL-1ß). These findings suggest that senescent astrocytes induced by various conditions and insults, including tau exposure, may represent a therapeutic target to inhibit or delay the progression of neurodegenerative diseases. We also discuss the pathological activity of extracellular tau in microglia and astrocytes, the disease relevance and diversity of tau forms, therapeutics targeting senescence in neurodegeneration, and the roles of p53 and its isoforms in astrocyte-mediated neurotoxicity and neuroprotection.

2.
BMC Cancer ; 21(1): 310, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33761896

RESUMO

BACKGROUND: Chromosomal inversions involving anaplastic lymphoma kinase (ALK) and echinoderm microtubule associated protein like 4 (EML4) generate a fusion protein EML4-ALK in non-small cell lung cancer (NSCLC). The understanding of EML4-ALK function can be improved by a functional study using normal human cells. METHODS: Here we for the first time conduct such study to examine the effects of EML4-ALK on cell proliferation, cellular senescence, DNA damage, gene expression profiles and transformed phenotypes. RESULTS: The lentiviral expression of EML4-ALK in mortal, normal human fibroblasts caused, through its constitutive ALK kinase activity, an early induction of cellular senescence with accumulated DNA damage, upregulation of p16INK4A and p21WAF1, and senescence-associated ß-galactosidase (SA-ß-gal) activity. In contrast, when EML4-ALK was expressed in normal human fibroblasts transduced with telomerase reverse transcriptase (hTERT), which is activated in the vast majority of NSCLC, the cells showed accelerated proliferation and acquired anchorage-independent growth ability in soft-agar medium, without accumulated DNA damage, chromosome aberration, nor p53 mutation. EML4-ALK induced the phosphorylation of STAT3 in both mortal and hTERT-transduced cells, but RNA sequencing analysis suggested that the different signaling pathways contributed to the different phenotypic outcomes in these cells. While EML4-ALK also induced anchorage-independent growth in hTERT-immortalized human bronchial epithelial cells in vitro, the expression of EML4-ALK alone did not cause detectable in vivo tumorigenicity in immunodeficient mice. CONCLUSIONS: Our data indicate that the expression of hTERT is critical for EML4-ALK to manifest its in vitro transforming activity in human cells. This study provides the isogenic pairs of human cells with and without EML4-ALK expression.

3.
Carcinogenesis ; 42(1): 1, 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33527994
4.
Lung Cancer ; 152: 58-65, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33352384

RESUMO

INTRODUCTION: The relationship between Body-Mass-Index (BMI) and lung cancer prognosis is heterogeneous. We evaluated the impact of sex, smoking and race on the relationship between BMI and overall survival (OS) in non-small-cell-lung-cancer (NSCLC). METHODS: Data from 16 individual ILCCO studies were pooled to assess interactions between BMI and the following factors on OS: self-reported race, smoking status and sex, using Cox models (adjusted hazard ratios; aHR) with interaction terms and adjusted penalized smoothing spline plots in stratified analyses. RESULTS: Among 20,937 NSCLC patients with BMI values, females = 47 %; never-smokers = 14 %; White-patients = 76 %. BMI showed differential survival according to race whereby compared to normal-BMI patients, being underweight was associated with poor survival among white patients (OS, aHR = 1.66) but not among black patients (aHR = 1.06; pinteraction = 0.02). Comparing overweight/obese to normal weight patients, Black NSCLC patients who were overweight/obese also had relatively better OS (pinteraction = 0.06) when compared to White-patients. BMI was least associated with survival in Asian-patients and never-smokers. The outcomes of female ever-smokers at the extremes of BMI were associated with worse outcomes in both the underweight (pinteraction<0.001) and obese categories (pinteraction = 0.004) relative to the normal-BMI category, when compared to male ever-smokers. CONCLUSION: Underweight and obese female ever-smokers were associated with worse outcomes in White-patients. These BMI associations were not observed in Asian-patients and never-smokers. Black-patients had more favorable outcomes in the extremes of BMI when compared to White-patients. Body composition in Black-patients, and NSCLC subtypes more commonly seen in Asian-patients and never-smokers, may account for differences in these BMI-OS relationships.

5.
Cancer Cell ; 38(6): 749-750, 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33321081
6.
Cancers (Basel) ; 12(11)2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33218139

RESUMO

The TP53 gene is a critical tumor suppressor and key determinant of cell fate which regulates numerous cellular functions including DNA repair, cell cycle arrest, cellular senescence, apoptosis, autophagy and metabolism. In the last 15 years, the p53 pathway has grown in complexity through the discovery that TP53 differentially expresses twelve p53 protein isoforms in human cells with both overlapping and unique biologic activities. Here, we summarize the current knowledge on the Δ133p53 isoforms (Δ133p53α, Δ133p53ß and Δ133p53γ), which are evolutionary derived and found only in human and higher order primates. All three isoforms lack both of the transactivation domains and the beginning of the DNA-binding domain. Despite the absence of these canonical domains, the Δ133p53 isoforms maintain critical functions in cancer, physiological and premature aging, neurodegenerative diseases, immunity and inflammation, and tissue repair. The ability of the Δ133p53 isoforms to modulate the p53 pathway functions underscores the need to include these p53 isoforms in our understanding of how the p53 pathway contributes to multiple physiological and pathological mechanisms. Critically, further characterization of p53 isoforms may identify novel regulatory modes of p53 pathway functions that contribute to disease progression and facilitate the development of new therapeutic strategies.

7.
Elife ; 92020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33112233

RESUMO

Long noncoding RNAs (lncRNAs) are often associated with polysomes, indicating coding potential. However, only a handful of endogenous proteins encoded by putative lncRNAs have been identified and assigned a function. Here, we report the discovery of a putative gastrointestinal-tract-specific lncRNA (LINC00675) that is regulated by the pioneer transcription factor FOXA1 and encodes a conserved small protein of 79 amino acids which we termed FORCP (FOXA1-Regulated Conserved Small Protein). FORCP transcript is undetectable in most cell types but is abundant in well-differentiated colorectal cancer (CRC) cells where it functions to inhibit proliferation, clonogenicity, and tumorigenesis. The epitope-tagged and endogenous FORCP protein predominantly localizes to the endoplasmic reticulum (ER). In response to ER stress, FORCP depletion results in decreased apoptosis. Our findings on the initial characterization of FORCP demonstrate that FORCP is a novel, conserved small protein encoded by a mis-annotated lncRNA that regulates apoptosis and tumorigenicity in well-differentiated CRC cells.

8.
Cancer Cell ; 38(5): 598-601, 2020 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-33038939

RESUMO

During the COVID-19 pandemic, research on "cytokine storms" has been reinvigorated in the field of infectious disease, but it also has particular relevance to cancer research. Interleukin-6 (IL-6) has emerged as a key component of the immune response to SARS-CoV-2, such that the repurposing of anti-IL-6 therapeutics for COVID-19 is now a major line of investigation, with several ongoing clinical trials. We lay a framework for understanding the role of IL-6 in the context of cancer research and COVID-19 and suggest how lessons learned from cancer research may impact SARS-CoV-2 research and vice versa.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/complicações , Citocinas/sangue , Inflamação/etiologia , Neoplasias/imunologia , Pneumonia Viral/complicações , Índice de Gravidade de Doença , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Citocinas/imunologia , Humanos , Inflamação/patologia , Neoplasias/sangue , Neoplasias/virologia , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/virologia
9.
J Pharm Biomed Anal ; 191: 113596, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32937240

RESUMO

Creatine riboside (CR) is a novel metabolite of cancer metabolism. It is a urinary diagnostic biomarker of lung and liver cancer risk and prognosis. The level of CR is highly positive correlated in tumor and urine indicating that it is derived from human lung and liver cancers. A precise and sensitive ultra-pressure liquid chromatography-tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed and validated for simultaneous quantification of the noninvasive biomarker CR, along with creatinine riboside (CNR), and their precursors creatine and creatinine, utilizing the labeled internal standard creatine riboside-13C,15N2 (CR-13C,15N2). Chromatography was carried out on a hydrophilic interaction chromatography column under a gradient mobile phase condition. MRM transitions were monitored for CR (264.1 > 132.1, m/z), CNR (246.1 > 113.9, m/z), creatine (132.0 > 72.0, m/z), creatinine (114.0 > 85.8, m/z) and CR-13C,15N2 (267.1 > 134.9, m/z) with a 11.0 min run time in the positive mode ionization. The calibration plot of the method was linear over the concentration range of 4.50-10,000 nM. Method validation was performed according to regulatory guidelines established for sensitivity, selectivity, calibration curve, stability at different storage conditions, reinjection reproducibility, ruggedness with acceptable accuracy, and precision. This assay was applied for the quantification of CR along with CNR, creatine and creatinine in a subset of urine and serum samples from the National Cancer Institute - Maryland (NCI-MD) cohort population controls and lung cancer cases. It can be standardized and used in multiple laboratories for cancer diagnosis and determining the efficacy of cancer therapy and monitoring cancer recurrence.

10.
Mol Cell Biol ; 40(21)2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32839292

RESUMO

Differentiation status of tumors is correlated with metastatic potential and malignancy. FOXA1 (forkhead box A1) is a transcription factor known to regulate differentiation in certain tissues. Here, we investigate FOXA1 function in human colorectal cancer (CRC). We found that FOXA1 is robustly expressed in the normal human colon but significantly downregulated in colon adenocarcinoma. Applying FOXA1 chromatin immunoprecipitation coupled with deep sequencing and transcriptome analysis upon FOXA1 knockdown in well-differentiated CRC cells and FOXA1 overexpression in poorly differentiated CRC cells, we identified novel protein-coding and lncRNA genes regulated by FOXA1. Among the numerous novel FOXA1 targets we identified, we focused on CEACAM5, a tumor marker and facilitator of cell adhesion. We show that FOXA1 binds to a distal enhancer downstream of CEACAM5 and strongly activates its expression. Consistent with these data, we show that FOXA1 inhibits anoikis in CRC cells. Collectively, our results uncover novel protein-coding and noncoding targets of FOXA1 and suggest a vital role of FOXA1 in enhancing CEACAM5 expression and anoikis resistance in CRC cells.


Assuntos
Neoplasias Colorretais/genética , Redes Reguladoras de Genes , Fator 3-alfa Nuclear de Hepatócito/genética , RNA Longo não Codificante/genética , Adenocarcinoma/genética , Adenocarcinoma/patologia , Anoikis/genética , Antígeno Carcinoembrionário/genética , Antígeno Carcinoembrionário/metabolismo , Diferenciação Celular/genética , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Neoplasias Colorretais/patologia , Elementos Facilitadores Genéticos , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Regulação Neoplásica da Expressão Gênica , Estudo de Associação Genômica Ampla , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Proteínas/genética , Pseudogenes
11.
Neurooncol Adv ; 2(1): vdaa057, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32642709

RESUMO

Continued improvements in cancer therapies have increased the number of long-term cancer survivors. Radiation therapy remains one of the primary treatment modalities with about 60% of newly diagnosed cancer patients receiving radiation during the course of their disease. While radiation therapy has dramatically improved patient survival in a number of cancer types, the late effects remain a significant factor affecting the quality of life particularly in pediatric patients. Radiation-induced brain injury can result in cognitive dysfunction, including hippocampal-related learning and memory dysfunction that can escalate to dementia. In this article, we review the current understanding of the mechanisms behind radiation-induced brain injury focusing on the role of neuroinflammation and reduced hippocampal neurogenesis. Approaches to prevent or ameliorate treatment-induced side effects are also discussed along with remaining challenges in the field.

12.
Cancer Cell ; 38(2): 158-160, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32649886

RESUMO

A paper published in Science probes over 1500 tumor samples from multiple cancer types for markers of a tumor microbiome and viable bacteria. Unique intertumoral and intracellular signatures associated with clinical biomarkers and metabolic pathways provide clues to the roles bacteria play in carcinogenesis.

13.
Carcinogenesis ; 41(1): 1, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32168376
15.
Sci Rep ; 9(1): 16930, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31729408

RESUMO

Chronic inflammation and chromosome aneuploidy are major traits of primary liver cancer (PLC), which represent the second most common cause of cancer-related death worldwide. Increased cancer fitness and aggressiveness of PLC may be achieved by enhancing tumoral genomic complexity that alters tumor biology. Here, we developed a scoring method, namely functional genomic complexity (FGC), to determine the degree of molecular heterogeneity among 580 liver tumors with diverse ethnicities and etiologies by assessing integrated genomic and transcriptomic data. We found that tumors with higher FGC scores are associated with chromosome instability and TP53 mutations, and a worse prognosis, while tumors with lower FGC scores have elevated infiltrating lymphocytes and a better prognosis. These results indicate that FGC scores may serve as a surrogate to define genomic heterogeneity of PLC linked to chromosomal instability and evasion of immune surveillance. Our findings demonstrate an ability to define genomic heterogeneity and corresponding tumor biology of liver cancer based only on bulk genomic and transcriptomic data. Our data also provide a rationale for applying this approach to survey liver tumor immunity and to stratify patients for immune-based therapy.


Assuntos
Heterogeneidade Genética , Genômica , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Instabilidade Cromossômica , Biologia Computacional , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Genômica/métodos , Humanos , Imunoterapia , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/metabolismo , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos do Interstício Tumoral/patologia , Masculino , Mutação , Gradação de Tumores , Estadiamento de Neoplasias , Análise de Sequência de DNA , Transcriptoma , Proteína Supressora de Tumor p53/genética
16.
Cancer Epidemiol Biomarkers Prev ; 28(10): 1704-1711, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31358519

RESUMO

BACKGROUND: Liver cancer is the second leading cause of cancer-related deaths worldwide. With a predicted 2.4-fold rise in liver cancer incidence by 2020, there is an urgent need for early, inexpensive diagnostic biomarkers to deploy in the clinic. METHODS: We employed ultraperformance liquid chromatography tandem mass-spectrometry (UPLC/MS-MS) for the quantitation of four metabolites, creatine riboside (CR), N-acetylneuraminic acid (NANA), cortisol sulfate, and a lipid molecule designated as 561+, in urine samples from the NCI-MD cohort comprising 98 hepatocellular carcinoma (HCC) cases, 101 high-risk subjects, and 95 controls. Validation was carried out in the TIGER-LC cohort [n = 370 HCC and intrahepatic cholangiocarcinoma (ICC) cases, 471 high-risk subjects, 251 controls], where ICC, the second most common primary hepatic malignancy, is highly prevalent. Metabolite quantitation was also conducted in TIGER-LC tissue samples (n = 48 ICC; n = 51 HCC). RESULTS: All profiled metabolites were significantly increased in liver cancer when compared with high-risk subjects and controls in the NCI-MD study. In the TIGER-LC cohort, the four-metabolite profile was superior at classifying ICC than a clinically utilized marker, CA19-9, and their combination led to a significantly improved model (AUC = 0.88, P = 4E-8). Metabolites CR and NANA were significantly elevated in ICC when compared with HCC cases in both urine and tissue samples. High levels of CR were associated with poorer prognosis in ICC. CONCLUSIONS: Four metabolites are significantly increased in HCC and ICC and are robust at classifying ICC in combination with the clinically utilized marker CA19-9. IMPACT: Noninvasive urinary metabolite biomarkers hold promise for diagnostic and prognostic evaluation of ICC.


Assuntos
Neoplasias dos Ductos Biliares/urina , Ductos Biliares Intra-Hepáticos/metabolismo , Ductos Biliares Intra-Hepáticos/patologia , Biomarcadores Tumorais/urina , Colangiocarcinoma/urina , Neoplasias dos Ductos Biliares/diagnóstico , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/patologia , Estudos de Casos e Controles , Colangiocarcinoma/diagnóstico , Colangiocarcinoma/metabolismo , Colangiocarcinoma/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC
17.
J Thorac Oncol ; 14(9): 1594-1607, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31163278

RESUMO

INTRODUCTION: The relationships between morbid obesity, changes in body mass index (BMI) before cancer diagnosis, and lung cancer outcomes by histology (SCLC and NSCLC) have not been well studied. METHODS: Individual level data analysis was performed on 25,430 patients with NSCLC and 2787 patients with SCLC from 16 studies of the International Lung Cancer Consortium evaluating the association between various BMI variables and lung cancer overall survival, reported as adjusted hazard ratios (aHRs) from Cox proportional hazards models and adjusted penalized smoothing spline plots. RESULTS: Overall survival of NSCLC had putative U-shaped hazard ratio relationships with BMI based on spline plots: being underweight (BMI < 18.5 kg/m2; aHR = 1.56; 95% confidence interval [CI]:1.43-1.70) or morbidly overweight (BMI > 40 kg/m2; aHR = 1.09; 95% CI: 0.95-1.26) at the time of diagnosis was associated with worse stage-specific prognosis, whereas being overweight (25 kg/m2 ≤ BMI < 30 kg/m2; aHR = 0.89; 95% CI: 0.85-0.95) or obese (30 kg/m2 ≤ BMI ≤ 40 kg/m2; aHR = 0.86; 95% CI: 0.82-0.91) was associated with improved survival. Although not significant, a similar pattern was seen with SCLC. Compared with an increased or stable BMI from the period between young adulthood until date of diagnosis, a decreased BMI was associated with worse outcomes in NSCLC (aHR = 1.24; 95% CI: 1.2-1.3) and SCLC patients (aHR=1.26 (95% CI: 1.0-1.6). Decreased BMI was consistently associated with worse outcome, across clinicodemographic subsets. CONCLUSIONS: Both being underweight or morbidly obese at time of diagnosis is associated with lower stage-specific survival in independent assessments of NSCLC and SCLC patients. In addition, a decrease in BMI at lung cancer diagnosis relative to early adulthood is a consistent marker of poor survival.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Neoplasias Pulmonares/fisiopatologia , Carcinoma de Pequenas Células do Pulmão/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Carcinoma de Pequenas Células do Pulmão/mortalidade , Análise de Sobrevida , Adulto Jovem
18.
Trends Cancer ; 5(4): 200-207, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30961828

RESUMO

The gut-brain axis formed by blood and lymphatic vessels paves the way for microbiota to impact the brain. Bacterial populations in the gut are a good candidate for a nongenetic factor contributing substantively to brain tumor development and to the success of therapy. Specifically, suppression of the immune system and induction of inflammation by microbiota sustain proliferative signaling, limit cell death, and induce angiogenesis as well as invasiveness. In addition, altered microbial metabolites and their levels could stimulate cell proliferation. We propose here a novel gear model connecting these complex interdisciplinary fields. Our model may impact mechanistic studies of brain cancer and better treatment outcomes through precision oncology.


Assuntos
Neoplasias Encefálicas/etiologia , Neoplasias Encefálicas/metabolismo , Encéfalo/imunologia , Encéfalo/metabolismo , Suscetibilidade a Doenças , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/metabolismo , Animais , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Transformação Celular Neoplásica , Citocinas/metabolismo , Gerenciamento Clínico , Suscetibilidade a Doenças/imunologia , Trato Gastrointestinal/microbiologia , Predisposição Genética para Doença , Humanos , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Imunomodulação , Microbiota , Medicina de Precisão
19.
Cancer Epidemiol Biomarkers Prev ; 28(4): 715-723, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30894353

RESUMO

BACKGROUND: Identifying genetic variants with pleiotropic associations across multiple cancers can reveal shared biologic pathways. Prior pleiotropic studies have primarily focused on European-descent individuals. Yet population-specific genetic variation can occur, and potential pleiotropic associations among diverse racial/ethnic populations could be missed. We examined cross-cancer pleiotropic associations with lung cancer risk in African Americans. METHODS: We conducted a pleiotropic analysis among 1,410 African American lung cancer cases and 2,843 controls. We examined 36,958 variants previously associated (or in linkage disequilibrium) with cancer in prior genome-wide association studies. Logistic regression analyses were conducted, adjusting for age, sex, global ancestry, study site, and smoking status. RESULTS: We identified three novel genomic regions significantly associated (FDR-corrected P <0.10) with lung cancer risk (rs336958 on 5q14.3, rs7186207 on 16q22.2, and rs11658063 on 17q12). On chromosome16q22.2, rs7186207 was significantly associated with reduced risk [OR = 0.43; 95% confidence interval (CI), 0.73-0.89], and functional annotation using GTEx showed rs7186207 modifies DHODH gene expression. The minor allele at rs336958 on 5q14.3 was associated with increased lung cancer risk (OR = 1.47; 95% CI, 1.22-1.78), whereas the minor allele at rs11658063 on 17q12 was associated with reduced risk (OR = 0.80; 95% CI, 0.72-0.90). CONCLUSIONS: We identified novel associations on chromosomes 5q14.3, 16q22.2, and 17q12, which contain HNF1B, DHODH, and HAPLN1 genes, respectively. SNPs within these regions have been previously associated with multiple cancers. This is the first study to examine cross-cancer pleiotropic associations for lung cancer in African Americans. IMPACT: Our findings demonstrate novel cross-cancer pleiotropic associations with lung cancer risk in African Americans.


Assuntos
Afro-Americanos/genética , Neoplasias Pulmonares/genética , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
20.
Neuro Oncol ; 21(4): 474-485, 2019 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-30615147

RESUMO

BACKGROUND: Cellular senescence and the senescence-associated secretory phenotype (SASP) may contribute to the development of radiation therapy-associated side effects in the lung and blood vessels by promoting chronic inflammation. In the brain, inflammation contributes to the development of neurologic disease, including Alzheimer's disease. In this study, we investigated the roles of cellular senescence and Δ133p53, an inhibitory isoform of p53, in radiation-induced brain injury. METHODS: Senescent cell types in irradiated human brain were identified with immunohistochemical labeling of senescence-associated proteins p16INK4A and heterochromatin protein Hp1γ in 13 patient cases, including 7 irradiated samples. To investigate the impact of radiation on astrocytes specifically, primary human astrocytes were irradiated and examined for expression of Δ133p53 and induction of SASP. Lentiviral expression of ∆133p53 was performed to investigate its role in regulating radiation-induced cellular senescence and astrocyte-mediated neuroinflammation. RESULTS: Astrocytes expressing p16INK4A and Hp1γ were identified in all irradiated tissues, were increased in number in irradiated compared with untreated cancer patient tissues, and had higher labeling intensity in irradiated tissues compared with age-matched controls. Human astrocytes irradiated in vitro also experience induction of cellular senescence, have diminished Δ133p53, and adopt a neurotoxic phenotype as demonstrated by increased senescence-associated beta-galactosidase activity, p16INK4A, and interleukin (IL)-6. In human astrocytes, Δ133p53 inhibits radiation-induced senescence, promotes DNA double-strand break repair, and prevents astrocyte-mediated neuroinflammation and neurotoxicity. CONCLUSIONS: Restoring expression of the endogenous p53 isoform, ∆133p53, protects astrocytes from radiation-induced senescence, promotes DNA repair, and inhibits astrocyte-mediated neuroinflammation.


Assuntos
Astrócitos/efeitos da radiação , Senescência Celular/efeitos da radiação , Lesões por Radiação/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Astrócitos/metabolismo , Neoplasias Encefálicas/radioterapia , Células Cultivadas , Irradiação Craniana/efeitos adversos , Humanos , Isoformas de Proteínas/metabolismo
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