RESUMEN

Iron release from macrophages is closely regulated by the interaction of hepcidin, a peptide hormone produced by hepatocytes, with the macrophage iron exporter ferroportin (FPN1). However, the functions of FPN1 in hepatocyte secretion and macrophage polarization remain unknown. CD68 immunohistochemical staining and double immunofluorescence staining for F4/80 and Ki67 in transgenic mouse livers showed that the number of macrophages in FPN1-/+ and FPN1-/- mouse livers was significantly increased compared to that in WT (FPN+/+) mice. FPN1 downregulation in hepatic cells increased the levels of the M2 markers CD206, TGF- ß, VEGF, MMP-9, Laminin, Collagen, IL-4 and IL-10. Furthermore, the expression of CD16/32 and iNOS, as M1 markers, exhibited the opposite trend. Meanwhile, α-SMA immunohistochemistry and Sirius red staining showed that the trend of liver fibrosis in FPN1-/- mice was more significant than that in control mice. Similarly, in vitro FPN1 knockdown in L02-Sh/L02-SCR liver cell lines yielded similar results. Taken together, we demonstrated that downregulated FPN1 expression in hepatocytes can promote the proliferation and polarization of macrophages, leading to hepatic fibrosis. Above all, the FPN1 axis might provide a potential target for hepatic fibrosis.

Asunto(s)

Proteínas de Transporte de Catión/metabolismo , Hepatocitos/metabolismo , Cirrosis Hepática/metabolismo , Macrófagos/metabolismo , Animales , Biomarcadores/metabolismo , Línea Celular Tumoral , Proliferación Celular/fisiología , Regulación hacia Abajo/fisiología , Hepcidinas/metabolismo , Humanos , Hierro/metabolismo , Hígado/metabolismo , Activación de Macrófagos/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Fenotipo , Células THP-1

RESUMEN

Cervical cancer is one of the most common malignancies that seriously threatens women's health. Krüppel­like factors (KLFs) have been reported to be associated with the progression of cervical cancer. The role of KLF1 in cervical cancer, which still remains unclear, was investigated in the present study. The expression of KLF1 was detected in different cervical cell lines by reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and western blotting. Cell proliferation, metastasis and invasion were respectively detected by Cell Counting Kit­8, wound healing and transwell assays. Associated factor expression was also detected by RT­qPCR and western blotting. In addition, the phosphorylation levels of phosphatidylinositol­3­kinase (PI3K) and protein kinase B (Akt) were determined by western blot analysis. The results revealed that KLF1 expression was promoted in SiHa, Caski and C4­1 cervical cancer cells. However, KLF1 knockdown suppressed cell proliferation, metastasis and invasion in SiHa cervical cancer cells. KLF1 knockdown also inhibited the expressions of Ki67, metastasis­associated antigen 1 and matrix metalloproteinase (MMP)­2. KLF1 knockdown promoted the expressions of nonmetastatic clone 23 type 1 and tissue inhibitor of metalloproteinase­2, and the expression of MMP­9 was promoted slightly as well. In addition, KLF1 knockdown inhibited the PI3K/Akt signaling pathway. Hence, it was concluded that KLF1 promoted metastasis and invasion via the PI3K/Akt signaling pathway in cervical cancer cells.

Asunto(s)

Regulación hacia Abajo/genética , Factores de Transcripción de Tipo Kruppel/genética , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología , Línea Celular Tumoral , Proliferación Celular , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Factores de Transcripción de Tipo Kruppel/metabolismo , Invasividad Neoplásica , Metástasis de la Neoplasia , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Interferencia de ARN , Transducción de Señal , Transfección

RESUMEN

Expression of CDC28 protein kinase regulatory subunit 1 (Cks1), an adaptor for cyclin-dependent kinases, is tightly regulated at transcriptional and posttranslational levels. Increased expression of Cks1 has been documented to be attributable to cancer progression, chemoresistance, and chemosensitivity. Here we report that ectopic overexpression of Cks1b in human lung cancer cells (Cks1b-OE) induces chemoresistance of the cells to cisplatin (CDDP) and doxorubicin (DOX) through mechanisms independent of its canonical Skp2-p27 pathway. Further dissection with application of shRNA and selective inhibitors reveals that Hsp90 and MEK1/2 are the critical components of the non-canonical pathways responsible for the Cks1b-induced chemoresistance. Interestingly, inhibition of either Hsp90 or MEK1/2 rendered a similar magnitude of antitumor activity by resensitization of the chemoresistant Cks1b-OE cells to CDDP and DOX, suggesting that both Hsp90 and MEK1/2 are essential to Cks1b for induction of chemoresistance. Moreover, 3-O-(Z)-coumaroyloleanolic acid (3-COA), an active ingredient of oleanolic acid in the leaves of E. oldhamii Maxim, that has been shown to have antitumor activity against A549 lung cancer cells, mimicked PU-H71, a Hsp90-specific inhibitor, in antitumor activity when used alone or in combination with CDDP or DOX in Cks1b-OE cells and recurrent primary human lung cancer cells both in vitro and in vivo, suggesting that 3-COA is a novel Hsp90 inhibitor. Our data report for the first time that Cks1b employs Hsp90 and MEK1/2 pathways in lung cancer cells to develop chemoresistance and identify 3-COA as a potential antitumor drug for clinical treatment of chemoresistant lung cancer.

Asunto(s)

Quinasas CDC2-CDC28/biosíntesis , Resistencia a Antineoplásicos/fisiología , Proteínas HSP90 de Choque Térmico/metabolismo , Neoplasias Pulmonares/metabolismo , Quinasas Quinasa Quinasa PAM/metabolismo , Ácido Oleanólico/farmacología , Adulto , Anciano , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Benzodioxoles/farmacología , Benzodioxoles/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Estudios de Seguimiento , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Quinasas Quinasa Quinasa PAM/antagonistas & inhibidores , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/fisiología , Masculino , Ratones , Ratones Desnudos , Persona de Mediana Edad , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/uso terapéutico , Purinas/farmacología , Purinas/uso terapéutico , Estudios Retrospectivos , Carga Tumoral/efectos de los fármacos , Carga Tumoral/fisiología , Células Tumorales Cultivadas

RESUMEN

BACKGROUND: The aim of this study was to analyze the expression of protein tyrosine kinase 6 (PTK6) in nasopharyngeal carcinoma (NPC) samples, and to identify whether PTK6 can serve as a biomarker for the diagnosis and prognosis of NPC. METHODS: We used quantitative RT-PCR and Western blotting analysis to detect mRNA and protein expression of PTK6 in NPC cell lines and immortalized nasopharyngeal epithelial cell lines. 31 NPC and 16 non-tumorous nasopharyngeal mucosa biopsies were collected to detect the difference in the expression of mRNA level of PTK6 by quantitative RT-PCR. We also collected 178 NPC and 10 normal nasopharyngeal epithelial cases with clinical follow-up data to investigate the expression of PTK6 by immunohistochemistry staining (IHC). PTK6 overexpression on cell growth and colony formation ability were measured by the method of cell proliferation assay and colony formation assay. RESULTS: The expression of PTK6 was higher in most of NPC cell lines at both mRNA and protein levels than in immortalized nasopharyngeal epithelial cell lines (NPECs) induced by Bmi-1 (Bmi-1/NPEC1, and Bmi-1/NPEC2). The mRNA level of PTK6 was high in NPC biopsies compared to non-tumorous nasopharyngeal mucosa biopsies. IHC results showed the expression of PTK6 was significantly correlated to tumor size (P<0.001), clinical stage (P<0.001), and metastasis (P=0.016). The patients with high-expression of PTK6 had a significantly poor prognosis compared to those of low-expression (47.8% versus 80.0%, P<0.001), especially in the patients at the advanced stages (42.2% versus 79.1%, P<0.001). Multivariate analysis indicated that the level of PTK6 expression was an independent prognostic factor for the overall survival of patients with NPC (P <0.001). Overexpression of PTK6 in HNE1 cells enhanced the ability of cell proliferation and colony formation. CONCLUSIONS: Our results suggest that high-expression of PTK6 is an independent factor for NPC patients and it might serve as a potential prognostic biomarker for patients with NPC.

Asunto(s)

Regulación Neoplásica de la Expresión Génica , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Adulto , Anciano , Biomarcadores de Tumor/metabolismo , Biopsia , Carcinoma , Línea Celular Tumoral , Proliferación Celular , Femenino , Perfilación de la Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Análisis Multivariante , Carcinoma Nasofaríngeo , Metástasis de la Neoplasia , Pronóstico , ARN Mensajero/metabolismo

RESUMEN

B-lymphoma mouse Moloney leukemia virus insertion region 1 (Bmi1), a member of the polycomb group, has elevated expression and is involved in the pathogenesis of various aggressive cancers, including nasopharyngeal carcinoma (NPC). To date, the mechanisms underlying the high expression of Bmi1 in NPC remain obscure. To gain new insights into the transcriptional regulation of BMI1, we cloned and characterized the promoter region of BMI1. Luciferase reporter assays demonstrated that the region from -783 to +375 showed significant promoter activity. With the use of a series of 5'-deletion and 3'-deletion promoter constructs in luciferase reporter assays, the +167/+232 and -536/-134 regions were found to be sufficient for full promoter activity. Transcriptional activity of the BMI1 promoter was dependent on the Sp1 binding site cluster (+181/+214) as well as the E-box elements (-181), and was abolished after mutation of the two cis-elements. Electrophoretic mobility shift assays and chromatin immunoprecipitation assays demonstrated that Sp1 bound to the region from +181 to +214 within the BMI1 promoter. In addition, gain-of-function and loss-of-function analyses revealed that Sp1 augmented Bmi1 expression. Further investigations using immunohistochemistry and quantitative RT-PCR disclosed a significant positive correlation between the expression of Sp1 and Bmi1 in normal nasopharyngeal epithelial cells, NPC cells, and NPC tissue specimens. In addition, Myc, the known transcription factor for BMI1 in neuroblastomas, also activated the transcription of BMI1 through binding to the E-box element (-181) within its promoter, and showed a positive correlation with the mRNA level of BMI1 in NPC. In conclusion, these findings provide valuable mechanistic insights into the role of Sp1 and c-Myc in BMI1 transcription in NPC, and suggest that targeting of Sp1 or c-Myc may be a potential therapeutic strategy for NPC.

Asunto(s)

Carcinoma/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Complejo Represivo Polycomb 1/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Factor de Transcripción Sp1/metabolismo , Secuencia de Bases , Sitios de Unión , Secuencia Conservada , Regulación Neoplásica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Datos de Secuencia Molecular , Complejo Represivo Polycomb 1/metabolismo , Regiones Promotoras Genéticas , Unión Proteica , Factor de Transcripción Sp1/genética , Células Tumorales Cultivadas

RESUMEN

BACKGROUND: The aim of this study is to explore the expression of beclin 1, an autophagy gene, in bladder cancer and to evaluate its clinical and prognostic significance in patients with bladder cancer. METHODS: Beclin 1 expression was examined at mRNA and protein levels by real-time quantitative polymerase chain reaction (RT-PCR), Western blotting, and immunohistochemistry in bladder cancer tissues and adjacent normal bladder tissues. The relationship between the expression of beclin 1 and clinicopathological characteristics and prognosis was statistically analyzed.
 RESULTS: mRNA level, protein expression and immunoreactivity of beclin 1 were decreased in bladder cancer tissues compared with adjacent normal tissues. Downregulation of beclin 1 was more frequent in tumors with higher histological grades (the expression of beclin 1 was reduced by 49.0% in G1 and G2, and by 71.8% in G3, p=0.010), and was also reduced by 69.5% in the muscle invasive type and by 51.1% in the non-muscle invasive type (p=0.04). Reduced beclin 1 expression was positively associated with higher histological grade and more advanced clinical stage (p<0.05). Kaplan-Meier survival analysis revealed that patients exhibiting lower beclin 1 expression experienced a shorter survival than those with higher expression (p=0.006). Cox proportional hazards regression analysis showed that beclin 1 protein is an independent predictor of survival (p=0.005).
 CONCLUSION: Beclin 1 has an influence on the progression of bladder cancer and might serve as a potential prognostic factor for patients with bladder cancer.

Asunto(s)

Proteínas Reguladoras de la Apoptosis/metabolismo , Carcinoma de Células Transicionales/metabolismo , Expresión Génica , Proteínas de la Membrana/metabolismo , Neoplasias de la Vejiga Urinaria/metabolismo , Proteínas Reguladoras de la Apoptosis/genética , Beclina-1 , Carcinoma de Células Transicionales/mortalidad , Carcinoma de Células Transicionales/patología , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Proteínas de la Membrana/genética , Persona de Mediana Edad , Pronóstico , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Estudios Retrospectivos , Carga Tumoral , Neoplasias de la Vejiga Urinaria/mortalidad , Neoplasias de la Vejiga Urinaria/patología

RESUMEN

Peptidyl-prolyl cis/trans isomerase (PPIase), PIN1, has been found to be a critical catalyst that involves in multiple oncogenic signaling pathways. Recently, several putative functional polymorphisms of the PIN1 gene have been identified to be associated with cancer risk. In this study, we tested the hypothesis that two common polymorphisms, c.-842G>C (rs2233678) and c.-667C>T (rs2233679), in the PIN1 promoter are associated with risk of lung cancer. In two independent case-control studies of 1,559 lung cancer cases and 1,679 controls conducted in Southern and Eastern Chinese population, we found that compared with the most common c.-842GG genotype, the carriers of c.-842C variant genotypes (GC + CC) had a decreased risk of lung cancer (odds ratio [OR] = 0.63, 95% confidence interval [CI] = 0.51-0.78, p = 1.13 × 10(-5) ). Although no association was observed between the c.-667C>T polymorphism and cancer risk, we found that the haplotype "C-C" had a greater protective effect (OR = 0.39, 95% CI = 0.23-0.67, p = 5.03 × 10(-4) ). The stratification analysis showed that the protective role of c.-842C variants was more pronounced in current smokers (p = 4.45 × 10(-5) ), especially in male smokers (p = 6.71 × 10(-6) ) and in those who smoked more than 20 pack-years (p = 2.30 × 10(-5) ) and the c.-842C variant genotypes interacted with smoking status (P(interaction) = 0.019) or pack-years smoked (P(interaction) = 0.008) on reducing cancer risk. Further functional assay revealed that the c.-842C variant allele had a lower transcription activity in luciferase assay and a lower DNA-binding ability with nuclear proteins, and low transcription activity in western blot assay. In conclusions, our data suggest that functional c.-842C variants and haplotype "C-C" in the PIN1 promoter contribute to decreased risk of lung cancer by diminishing the promoter activity, which may be susceptibility biomarkers for lung cancer.

Asunto(s)

Adenocarcinoma/genética , Pueblo Asiatico , Haplotipos , Neoplasias Pulmonares/genética , Isomerasa de Peptidilprolil/genética , Polimorfismo de Nucleótido Simple , Adenocarcinoma/etnología , Adenocarcinoma del Pulmón , Adulto , Alelos , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Neoplasias Pulmonares/epidemiología , Neoplasias Pulmonares/etnología , Masculino , Persona de Mediana Edad , Peptidilprolil Isomerasa de Interacción con NIMA , Riesgo , Factores de Riesgo

RESUMEN

BACKGROUND: The oncogene CDC25B phosphatase plays an important role in cancer cell growth. We have recently reported that patients with esophageal squamous cell carcinoma (ESCC) have significantly higher serum levels of CDC25B autoantibodies (CDC25B-Abs) than both healthy individuals and patients with other types of cancer; however, the potential diagnostic or prognostic significance of CDC25B-Abs is not clear. The aim of this study is to evaluate the clinical significance of serum CDC25B-Abs in patients with ESCC. METHODS: CDC25B autoantibodies were measured in sera from both 134 patients with primary ESCC and 134 healthy controls using a reverse capture enzyme-linked immunosorbent assay (ELISA) in which anti-CDC25B antibodies bound CDC25B antigen purified from Eca-109 ESCC tumor cells. The clinicopathologic significance of CDC25B serum autoantibodies was compared to that of the tumor markers carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC-Ag) and cytokeratin 19 fragment antigen 21-1(CYFRA21-1). RESULTS: Higher levels of CDC25B autoantibodies were present in sera from patients with ESCC (A450 = 0.917, SD = 0.473) than in sera from healthy control subjects (A450 = 0.378, SD = 0.262, P < 0.001). The area under the receiver operating characteristic (ROC) curve for CDC25B-Abs was 0.870 (95% CI: 0.835-0.920). The sensitivity and specificity of CDC25B-Abs for detection of ESCC were 56.7% and 91.0%, respectively, when CDC25-Abs-positive samples were defined as those with an A450 greater than the cut-off value of 0.725. Relatively few patients tested positive for the tumor markers CEA, SCC-Ag and CYFRA21-1 (13.4%, 17.2%, and 32.1%, respectively). A significantly higher number of patients with ESCC tested positive for a combination of CEA, SCC, CYFRA21-1 and CDC25B-Abs (64.2%) than for a combination of CEA, SCC-Ag and CYFRA21-1 (41.0%, P < 0.001). The concentration of CDC25B autoantibodies in serum was significantly correlated with tumor stage (P < 0.001). Although examination of the total patient pool showed no obvious relationship between CDC25B autoantibodies and overall survival, in the subgroup of patients with stage III-IV tumors, the cumulative five-year survival rate of CDC25B-seropositive patients was 6.7%, while that of CDC25B-seronegative patients was 43.4% (P = 0.001, log-rank). In the N1 subgroup, the cumulative five-year survival rate of CDC25B-seropositive patients was 13.6%, while that of CDC25B-seronegative patients was 54.5% (P = 0.040, log-rank). CONCLUSIONS: Detection of serum CDC25B-Abs is superior to detection of the tumor markers CEA, SCC-Ag and CYFRA21-1 for diagnosis of ESCC, and CDC25B-Abs are a potential prognostic serological marker for advanced ESCC.

Asunto(s)

Autoanticuerpos/inmunología , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/inmunología , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/inmunología , Fosfatasas cdc25/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Antígenos de Neoplasias/sangre , Antígenos de Neoplasias/inmunología , Autoanticuerpos/sangre , Antígeno Carcinoembrionario/sangre , Carcinoma de Células Escamosas/sangre , Carcinoma de Células Escamosas/patología , Estudios de Casos y Controles , Línea Celular Tumoral , Ensayo de Inmunoadsorción Enzimática , Neoplasias Esofágicas/sangre , Neoplasias Esofágicas/patología , Femenino , Humanos , Estimación de Kaplan-Meier , Queratina-19 , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Curva ROC , Sensibilidad y Especificidad , Serpinas/sangre

RESUMEN

BACKGROUND & OBJECTIVE: Dendritic cells (DCs) can activate immunologic naive T cells to initiate antigen-specific immune responses. This study was to in vitro induce mature DCs from malignant pleural effusions of patients with lung cancer. METHODS: Malignant pleural effusions (500-1 000 ml) were collected from 16 patients with primary lung cancer. Precursory DCs were obtained through density gradient centrifugation and magnetic cell sorting from malignant pleural effusions, and cultured with interleukin-4 (IL-4), granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha). Morphology of DCs was observed under invert optical microscope and electronic microscope; phenotype of DCs was analyzed by flow cytometry. Effect of DCs on proliferation of tumor infiltrative lymphocytes (TILs) was observed through mixed lymphocyte reaction (MLR). RESULTS: Mature DCs with typical morphology (elongated dendritic processions observed under invert optical microscope and electronic microscope) were induced from malignant pleural effusions. Expressions of surface phenotypes were higher in DCs induced for 48 h than in DCs induced for 0, 24, 96, and 192 h. When activated with DCs, proliferation of TILs was enhanced. CONCLUSION: Mature DCs could be induced from malignant pleural effusions of patients with lung cancer.

Asunto(s)

Células Dendríticas/fisiología , Neoplasias Pulmonares/patología , Linfocitos Infiltrantes de Tumor/citología , Derrame Pleural Maligno/patología , Adenocarcinoma/patología , Anciano , Carcinoma de Células Pequeñas/patología , Carcinoma de Células Escamosas/patología , Proliferación Celular , Células Cultivadas , Células Dendríticas/efectos de los fármacos , Femenino , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Humanos , Interleucina-4/farmacología , Masculino , Persona de Mediana Edad , Factor de Necrosis Tumoral alfa/farmacología

RESUMEN

To investigate the relationship among 8-OH-dG and the development of human lung cancer and cancer related genes, an 8-OH-dG-specific monoclonal antibody and biotin-streptavidin immuno-staining were used to detect the 8-OH-dG in 150 cases of human lung cancer tissues, 120 adjacent lung tissues without cancer cells, 40 benign lung lesions and 40 normal lung tissues. The expressions of P53, C-MYC, K-RAS, BCL-2 and hTERT(human telomerase reverse transcriptase) were determined by immunohistochemistry and the relationship among the 8-OH-dG and these genes was analyzed. The 8-OH-dG were positive in 139 of 150 (92.7%) lung cancer specimens, and the percentage of adduct labeling cell in lung cancer specimens was (24.00 +/- 25.11)% (mean +/- SE). 21 of 120 (17.5%) adjacent lung tissues were adduct positive, and the percentage of adduct labeling cell was 2.42 +/- 5.98%. 4 of 40 (10.0%) benign lung lesions were adduct positive, and the percentage of adduct labeling cell was 0.80 +/- 1.30%, whereas 2 of 40 (5.0%) normal lung tissues were weak positive with 8-oh-dG, and the percentage of adduct labeling cell in this group was (0.34 +/- 1.01)%. The level of 8-OH-dG in lung cancer tissues was significantly higher than that of adjacent lung tissues, benign lung lesions and normal lungs (P < 0.01). The lung cancer patients were stratified by sex, age, cell types and smoking history, but these characteristics were not correlated with the level of 8-OH-dG. In the investigation of the relationship between the 8-OH-dG and five cancer related genes, higher 8-OH-dG levels were observed in lung cancer patients with over-expression of K-RAS and BCL-2 than those of negative expressed patients (P-value were 0.035 and 0.034 respectively), whereas the expression of P53, C-MYC and hTERT were not correlated with level of 8-OH-dG. 8-OH-dG was an important biomarker that may reflect the oxidative DNA damages of cells, and 8-OH-dG may affect K-RAS and BCL-2 genes in the carcinogenesis of lung cancer.

Asunto(s)

Daño del ADN , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Neoplasias Pulmonares/genética , Pulmón/metabolismo , 8-Hidroxi-2'-Desoxicoguanosina , Proteínas de Unión al ADN , Expresión Génica , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas c-myb/metabolismo , Telomerasa/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteínas ras/metabolismo

RESUMEN

OBJECTIVE: To study the role of O(6)-methylguanine-DNA methyltransferase (hMGMT) in the development of human lung cancer. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) method was applied to measure hMGMT mRNA expression in 150 lung cancer specimens, 40 normal lung tissues, and in the peripheral mononuclear blood cells from 50 lung cancer cases and 50 normal controls. The protein expressions of p53, C-MYC and K-RAS were assessed by immuno-histochemistry. The effects of some exposure factors on the expression of hMGMT gene were analyzed. The relationships between hMGMT gene and cancer related genes p53, C-MYC and K-RAS were investigated. RESULTS: The mRNA of hMGMT was low or absent in 49 of 150 (32.7%) lung cancer specimens, whereas 2 of 40 (5%) normal lung tissues had reduced the levels of hMGMT mRNA. The low expression of hMGMT seemed to be a risk factor of lung cancer, with a OR of 9.22 (2.05-57.65). Reduced expression levels of hMGMT mRNA were observed in 10 of 50 (20%) lung cancer patients' peripheral mononuclear blood cells, and 2 of 50 (4%) blood cells among normal controls. When investigating the exposure factors which affecting the expression of hMGMT gene, we noticed that smoking was suppressing the expression of hMGMT gene. Interestingly, over-expression of K-RAS oncogene was significantly correlated with low expression of hMGMT (P < 0.05). However, the expressions of p53 and C-myc were not correlated with the status of hMGMT gene. CONCLUSION: hMGMT might play an important role in the development of human lung cancer. Low expression of hMGMT gene seemed to be a risk factor for lung cancer which could be used as a valuable biomarker on susceptibility of human lung cancers.

Asunto(s)

Reparación del ADN/genética , Neoplasias Pulmonares/genética , O(6)-Metilguanina-ADN Metiltransferasa/genética , Proteínas ras/genética , Adulto , Anciano , Biomarcadores de Tumor , Carcinoma de Células Escamosas/enzimología , Carcinoma de Células Escamosas/genética , China/epidemiología , Femenino , Genes ras/genética , Humanos , Neoplasias Pulmonares/enzimología , Masculino , Persona de Mediana Edad , O(6)-Metilguanina-ADN Metiltransferasa/biosíntesis , O(6)-Metilguanina-ADN Metiltransferasa/metabolismo , Mutación Puntual , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Fumar/efectos adversos , Proteínas ras/biosíntesis

RESUMEN

OBJECTIVE: To investigate lung carcinogenesis associated genes in human lung squamous cell carcinoma and malignant transformation of human bronchial epithelial cells induced by chemical carcinogens with cDNA microarray. METHODS: The gene expression patterns were detected in all specimens by cDNA microarray which representing 4 096 different human genes. The differences in gene expression among 6 cases of human lung squamous cell carcinoma tissues and 6 normal lung tissues were analyzed. The different gene expression patterns between the normal human bronchial epithelial cell lines (16HBE) and the malignant transformation of human bronchial epithelial cells induced by Benzo(a)pyrene metabolite BPDE (anti-Benzo(a)pyrene diol-epoxide,BPDE) and crystalline nickel sulfide were also studied by that method. The similar changed genes among those gene expression patterns were identified as lung carcinogenesis associated genes. RESULTS: Among the 4096 genes of cDNA microarrays, there were 171 genes expressed differently among lung cancer tissues and normal lungs, 143 genes expressed differently between BPDE transformed cells and normal 16HBE cell lines, 151 genes differed between nickel sulfide transformed cells and normal 16HBE cell lines. By comparing the gene expression profiles, there were 89 similar changed genes which might be associated with human lung carcinogenesis, 39 of which were up regulated: 6 oncogenes, 4 cell cycle control genes, 6 cell proliferation genes, 8 metastasis genes, 3 neuroendocrine genes, 1 drug-resister gene, 1 anti-apoptosis gene, 1 oxidative gene and other 9 genes. 50 genes were down-regulated: 7 tumor suppression genes, 11 DNA repair genes, 1 antioxidant genes, 3 GST family genes, 3 cell framework genes, 2 apoptosis induced genes, 5 signal conduction genes, 5 cytokines and their receptor genes, 7 metabolization genes, 1 cell matrix genes, and other 5 genes. CONCLUSION: cDNA microarray can be applied to study gene expression profiles effectively and to screen human lung carcinogenesis associated genes.

Asunto(s)

Bronquios/efectos de los fármacos , Carcinoma de Células Escamosas/genética , Transformación Celular Neoplásica/genética , Neoplasias Pulmonares/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , 7,8-Dihidro-7,8-dihidroxibenzo(a)pireno 9,10-óxido/toxicidad , Bronquios/patología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/patología , Humanos , Níquel/toxicidad