EGCG induces lung cancer A549 cell apoptosis by regulating Ku70 acetylation.

Lung cancer is the leading cause of cancer-related death worldwide. (-)-Epigallocatechin-3-gallate (EGCG) is a potential chemopreventive and therapeutic agent for lung cancer. Induction of apoptosis was examined using Annexin V/PI double staining flow cytometry. Western blot analysis detected the protein expression of cleaved caspase-3, Bax and Bcl-xL. Co-immunoprecipitation was used to detect the interaction of Ku70-Bax and the acetylation status of Ku70. Treatment of A549 cells with EGCG-induced apoptosis via increased expression of cleaved caspase-3 and Bax, but decreased expression of Bcl-xL. EGCG upregulated the K70 acetylation status of A549 cells and downregulated the interaction of Bax-Ku70 in a concentration- and time-dependent manner. The apoptosis-promoting effect of EGCG on A549 cells was obviously weakened, along with strengthening of the Bax-Ku70 interaction, after pCDNA3.1(+)-Ku70 plasmid and pCDNA3.1(+)-Ku70539/542R plasmid transfection. Our results established a role of EGCG in inducing cell apoptosis by suppressing Bax activity. Regulating Ku70 acetylation by EGCG, that block the interaction between Ku70 and Bax, will result in lung cancer cell apoptosis.

Biological characteristics and epidermal growth factor receptor tyrosine kinase inhibitors efficacy of EGFR mutation and its subtypes in lung adenocarcinoma.

Mutation of epidermal growth factor receptor (EGFR) gene has been reported to be present in lung adenocarcinoma (LAC). In this study, we extensively investigated the impact of patients' biological characteristics on EGFR mutation and the impact of EGFR mutation subtypes on targeted therapy of advanced LAC. We examined EGFR exons18to21status in169 LAC patients by direct sequencing to study the impact of patients' biological characteristics on the EGFR mutational spectrum. And then, 59 patients with advanced LAC harboring EGFR exon 19 deletions(del 19) or exon 21 point mutation(L858R) mutations received first-line treatment of gefitinib or erlotinib, the efficacy of treatment, and the progression-free survival (PFS) of these patients were recorded. The frequency of the EGFR mutation and its subtypes and the variables associated with the EGFR mutation after removing the confound factors were investigated by the logistic analysis using all samples (n = 169). The EGFR mutation was significantly associated with well-differentiated tumor and excessive household cooking fumes(P < 0.05). The deletions in exon 19 were more frequently associated with well-differentiated tumor (P < 0.05). The overall frequency of the EGFR mutation was 49 %. Then the impact of EGFR mutation subtypes on targeted therapy were investigated by the retrospective analysis on 59 advanced LAC patients with del 19 or L858R mutations and treated first-line with erlotinib or gefitinib. The deletions in exon 19 got longer PFS (P < 0.05). But there were no differences in PFS between erlotinib therapy and gefitinib therapy. EGFR mutations were more frequently in high tumor differentiation and excessive household cooking fumes LAC. The del 19 mutation rate is relatively high with a high differentiation degree in advanced lung adenocarcinoma. The deletions in exon 19 may benefit more from first-line targeted therapy of advanced LAC compared with exon 21 point mutation L858R. There was no significant difference between the efficacy of gefitinib and erlotinib treatments associated with EGFR mutation and its subtypes.

Inhibition of nuclear factor-κB activity enhanced chemosensitivity to cisplatin in human lung adeno-carcinoma A549 cells under chemical hypoxia conditions.

BACKGROUND: Tumor hypoxia, one of the features of solid tumors, is associated with chemo-resistance. Recently, nuclear factor-κB (NF-κB) was found to be activated during hypoxia. However, the impact of NF-κB activation on chemo-resistance during hypoxia remains unknown. METHODS: Human lung adenocarcinoma A549 cells were transfected with NF-κB p65siRNA and treated with cobalt chloride (CoCl2) to mimic hypoxia in the presence or absence of cisplatin. NF-κB expression was measured by Western blotting, immune-fluorescence and real-time PCR. Hypoxia-inducible factor-1α (HIF-1α) and Bcl-2 expression were determined by Western blotting. Cell apoptosis and survival with half-maximum inhibitory concentration (IC50) of cisplatin were determined by Annexin V-FITC/PI and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), respectively. RESULTS: Exposure of A549 cells to CoCl2 increased nuclear HIF-1a protein expression, and enhanced NF-κB p65 protein nuclear accumulation (the mark of NF-κB activation) in a time and dose dependant manner. CoCl2 did not promote apoptosis in A549 cells; on the contrary, it reduced cisplatin-induced apoptosis and increased the IC50 of cisplatin. However, when we inhibited CoCl2-induced activation of NF-κB through NF-κB p65siRNA, cisplatin-induced apoptosis was increased and IC50 of cisplatin was reduced to levels similar to those in control cells. Meanwhile, CoCl2-induced Bcl-2 overexpression was down-regulated in the presence of cisplatin when NF-κB activity was inhibited. CONCLUSION: Up-regulating Bcl-2 might be involved in NF-κB activation induced resistance to cisplatin in A549 cells under CoCl2-induced chemical hypoxia.

Role of Ku70 and Bax in epigallocatechin-3-gallate-induced apoptosis of A549 cells in vivo.

EGCG (epigallocatechin-3-gallate), the major catechin found in green tea, has been demonstrated to inhibit proliferation and induce apoptosis in a number of types of tumors. Recent studies reveal that EGCG has various anticancer effects. This study investigated a further possible molecular mechanism of the anticancer effects of EGCG in murine lung cancer xenografts. In the study, A549 human lung cancer cells were injected into nude mice. Tumor volume was used to measure cancer cell growth. The weight of the animals was used to assess the toxicity of the drugs. The expression of protein and mRNA was assayed by western blot analysis and RT-PCR, respectively. The interaction between Bax and Ku70 was determined by immunoprecipitation. Our results suggest that EGCG induced A549 lung cancer cell apoptosis in vivo, and had less toxic effects compared to classical anticancer drugs. EGCG may inhibit the surrogate markers of proliferation and apoptosis (caspase 3) in A549 tumor xenografts in vivo. In addition, EGCG downregulated the expression of Bcl-xl and upregulated the expression of Bax mRNA and protein. Further experiments indicated that EGCG downregulated the protein expression of Ku70 and interrupted the binding of Ku70 and Bax. This is the first study demonstrating that the induction of apoptosis by EGCG may be caused by the downregulation of Ku70 and that EGCG disrupts the interaction between Ku70 and Bax in lung cancer.

Analysis of two cases with bronchopulmonary neurofibromatosis.

Neurogenic tumor of lung is very rare. Only few cases have been reported in the literature. We present here two cases of bronchopulmonary neurofibromatosis in two adults. In both cases, attempts at imaging failed to diagnose the case, and it was the histological study that ensured the diagnosis of neurofibromatosis. Biopsy specimens showed bundles of spindle-shaped cells mixed with collagen, and on immunohistochemistry some cells were positive for S-100 protein.

Effects of Arkadia on airway remodeling through enhancing TGF-beta signaling in allergic rats.

Upregulation of transforming growth factor-beta (TGF-beta) signaling is interrelated with the development of airway remodeling. In this study, we examined the role of two E3 ubiquitin ligases, Arkadia and Smurf2, which are critically required for TGF-beta signaling in airway remodeling. Rats were immunized with ovalbumin (OVA) and then challenged with an OVA aerosol. In in vitro experiments, normal human bronchial epithelial cells were stimulated with TGF-beta(1) with or without the preincubation of Arkadia/Smurf2 small interfering RNA (siRNA) or lactacystin (an inhibitor of proteasomal degradation). In the lungs of OVA-treated rats, a large number of inflammatory cells were present near the airways. An increased subepithelial collagen deposition was associated with high expression levels of Smad7, SnoN and Ski mRNAs, Arkadia, Smurf2, and TGF-beta type I receptor (TbetaRI), but low expression levels of Smad7, SnoN and Ski proteins. Smad7, SnoN and Ski interacted with both Arkadia and Smurf2 while TbetaRI only interacted with Smurf2 but not with Arkadia. In in vitro experiments, the inhibitory effect of TGF-beta(1) on the expression of Smad7, SnoN and Ski was reversed by Arkadia siRNA and lactacystin, whereas the stimulatory effect of TGF-beta(1) on the expression of TbetaRI protein and Smad7/SnoN/Ski mRNAs was not affected. In contrast, Smurf2 siRNA did not influence the effects of TGF-beta(1) on the expression of the above proteins. Our results suggest that Arkadia may contribute to the pathogenesis of airway remodeling through enhancing TGF-beta signaling by inducing the reduction of Smad7, SnoN and Ski proteins in OVA-sensitized and -challenged rats.

Trichostatin A sensitizes cisplatin-resistant A549 cells to apoptosis by up-regulating death-associated protein kinase.

AIM: To investigate the apoptosis-inducing effect of trichostatin A (TSA) in the human lung adenocarcinoma cisplatin-resistant cell line (A549/CDDP) and to examine whether TSA can enhance sensitivity to cisplatin treatment and the underlying molecular mechanisms of such an enhancement. METHODS: Cell viability was evaluated using the Neutral Red assay. Apoptosis was assessed using Hoechst 33258 staining and flow cytometry analysis. Protein expression was detected by Western blotting. To determine the role of Death-associated protein kinase (DAPK) in TSA-induced apoptosis in the A549/CDDP cell line, cells were transfected with pcDNA3.1(+)-DAPK, which has a higher expression level of DAPK compared to endogenous expression, and DAPK activity was inhibited by both over-expression C-terminal fragment of DAPK which may competitive binding DAPK substrates to inhibit the function of DAPK and RNA interference. RESULTS: TSA induced apoptosis in both A549 cells and A549/CDDP cells. TSA enhanced the sensitivity of A549/CDDP cells to cisplatin, along with concomitant DAPK up-regulation. When DAPK was over-expressed, A549/CDDP cells became sensitive to cisplatin and the cytotoxicity of TSA could be increased. Moreover, the cytotoxicity of TSA could be alleviated by inhibition of DAPK activity by the expression of a recombinant C-terminal fragment of DAPK or RNA interference. CONCLUSION: TSA induced sensitivity to cisplatin treatment in cisplatin-resistant A549 cells. The up-regulation of DAPK is one of the mechanisms mediating sensitization to TSA-induced apoptosis in cisplatin-resistant cells.

[CYP1A1 polymorphisms, lack of glutathione S-transferase M1 (GSTM1), cooking oil fumes and lung cancer risk in non-smoking women].

OBJECTIVE: to study the correlation of polymorphisms of CYP1A1 MspI, GSTM1 null genotype, cooking oil fumes independently and in combination with the risk of non-smoking lung cancer in females. METHODS: one hundred and sixty female non-smoking patients with primary lung cancer and 160 controls were enrolled from Xiangya Hospital of Central South University. PCR-RELP and PCR were used to detect the distribution of CYP1A1 MspI and GSTM1 genotypes respectively. The correlation of these genes and cooking oil fumes with the susceptibility to lung cancer was analyzed. RESULTS: There was a significant difference in the frequencies of cooking oil fumes exposure between cancer cases and controls (χ(2) = 10.734, P < 0.01);but there was no statistical difference in CYP1A1 MspI polymorphisms between the 2 groups (χ(2) = 3.731, P > 0.05). The combination of CYP1A1 polymorphisms and cooking oil fumes significantly increased the risk of lung cancer. The frequencies of GSTM1 null genotype was significantly different between cancer cases and controls (χ(2) = 0.518, P < 0.05). The risk of lung cancer was higher in those with the GSTM1 null genotype and the OR was 1.697 (95%CI 1.090 - 2.640). Individuals with both GSTM1 null genotype and exposure to cooking fumes had a higher risk of cancer than those with only one of them, the OR being 3.617 (95%CI 1.899 - 6.891). The combination of the two genes significantly increased the risk of lung cancer. CONCLUSIONS: cooking oil fumes exposure was a risk factor for non-smoking lung cancer in females. The combination of CYP1A1 with cooking oil fume increased the risk of female lung cancer. GSTM1 null genotype was associated with risk of lung cancer in non-smoking females. The combination of GSTM1 null genotype and cooking oil fumes significantly increased the risk of female lung cancer. The combination of CYP1A1 and GSTM1 significantly increased the risk of lung cancer.

[Clinical experience of successful management of a human case with A/H5N1 infection in Hunan Province].

OBJECTIVE: To study the clinical features and successful management of a survived human case with A/H5N1 infection. METHODS: The data of a confirmed case of human case with A/H5N1 infection in Hunan province were collected and analyzed. RESULTS: This patient with A/H5N1 infection in Hunan province was confirmed by reverse-transcription polymerase chain reaction (RT-PCR) for A/H5N1 in airway secretions. The main clinical presentations included fever, cough and dyspnea. An extensive pulmonary infiltration developed quickly, followed by multi-organ dysfunction. Early administration of oseltamivir, early protection of organ function and extensive support were effective for the cure of the disease in this case. CONCLUSION: Early administration of oseltamivir, early protection of organ function and adequate support therapy may be useful for the treatment of human A/H5N1 infection.

[Effects of secretory leukocyte protease inhibitor on expression of inflammation mediators in normal human bronchial epithelial cells induced by cigarette smoke extract].

OBJECTIVE: To study the effect of secretory leukocyte protease inhibitor (SLPI) on the expression of MMP-9 and IL-8 in normal human bronchial epithelial (NHBE) cells induced by cigarette smoke extract (CSE), and therefore to explore the mechanisms of SLPI for protecting the local airways of chronic inflammatory diseases. METHODS: The experiments of cultured airway epithelia cells in vivo were randomly divided into 4 groups, including a control group, a CSE group, a SLPI group, and a SLPI + CSE group. The expression level of IL-8 in NHBE cell supernatant was examined by ELISA. The expression level of MMP-9 protein in NHBE cells was evaluated by using immunocytochemical stain method. One way analysis of variance was employed in significance test of different groups, followed by SNK test with equal variances and Dunnett3 test with unequal variances. RESULTS: A small quantities of MMP-9 and IL-8 expression were observed in the control group NHBE cells. The mean integral expression of MMP-9 protein was (3.1 +/- 0.5), and the concentration of IL-8 in NHBE cell supernatant was (4.9 +/- 0.6) ng/L. After exposure to CSE for different times, the expression of MMP-9 and IL-8 in NHBE cells of the CSE group was higher than those of in control group. The expression levels of MMP-9 and IL-8 were dependent on CSE exposure time within certain limits. The highest expression was observed at the time of 24 h exposure to CSE. The mean integral expression of MMP-9 protein was 6.6 +/- 0.4, and the concentration of IL-8 in NHBE cell supernatant was (17.7 +/- 1.9) ng/L. But subsequently the levels decreased significantly in 36 h. When NHBE cells were exposed to 10 microg/L SLPI, the expression levels of MMP-9 and IL-8 were inhibited. The integral expression of MMP-9 protein was 0.8 +/- 0.5, and the concentration of IL-8 in NHBE cell supernatant was (0.7 +/- 0.6) ng/L. CONCLUSION: SLPI inhibited the expression of MMP-9 and IL-8 in NHBE cells induced by cigarette smoking extract.

[Study on the relationship between the polymorphism of p53 gene intron 7 and non-small cell lung cancer (NSCLC) and p53 mutation in NSCLC tissues].

OBJECTIVE: To investigate the relationship between p53 gene intron 7 polymorphism and non-small cell lung cancer (NSCLC). METHODS: One hundred and five patients with NSCLC and 100 controls were selected with case-control analysis. Polymerase chain reaction (PCR), Apa I restriction enzyme digestion and agarose gel electrophoretic separation were used to identify genotypes of p53 intron 7 in peripheral blood. Then, NSCLC biopsy tissues (n=64) and NSCLC paraffin-embedded tissues (n=40) were selected for mutation analysis. PCR products of p53 exons 5-8 were sequenced on an automated sequencer following the identification of intron 7 genotypes as previously described. RESULTS: In NSCLC patients, the homozygote positive for ApaI site in p53 intron 7 was 23.8%, the homozygote negative was 12.34%, and the heterozygote was 63.8%. Whereas in control group, the homozygote positive, the homozygote negative and the heterozygote were 44.0%, 11.0% and 45.0%, respectively (P<0.01). In the second part, mutation rate of p53 exons 5-8 was 20.0%, 50.0% and 52.9% in samples with ApaI positive, negative and heterozygotes, respectively (P<0.05). CONCLUSION: p53 intron 7 ApaI polymorphism may be associated with human NSCLC.

[Access to tuberculosis care among community patients with chronic cough in Yangzhong County, Jiangsu Province].

OBJECTIVE: To describe the access to tuberculosis care among patients with long-term chronic cough (potential TB cases), and to study the impact of socio-economic and demographic factors on the access. METHODS: Randomized cluster sampling was used to select 20 villages as the study sites from 94 villages in a county where modern TB control program with DOTS has not been established--Yangzhong in Jiangsu Province, China. 171 patients with chronic cough, identified from all residents (n=33549) aged >14 years were interviewed using a structured questionnaire. Fluoroscopy and sputum smear were used for diagnosis. RESULTS: The median delay of patients (n=56) who did not seek any health care (quartile: 51 days-93 days) was 67 days, longer than the delay to first health care provider (10 days, quartile: 4 days-31 days) and patient's delay (15 days, quartile: 5-31 days) of those who had sought health care (P = 0.000). Uninsured patients were 42.2% less likely to access health facility and general hospitals than insured patients; meanwhile, they had a longer delay to first health care provider and general hospital. Men were less likely to seek health care service in primary health care provider. Farmers had a longer delay to first health care provider, so did the patients whose houses were far from health facilities. CONCLUSION: Potential TB patients with long-term cough in the non-program area of China have poor access to tuberculosis care,which could affect the detection of TB patients in population. Medical insurance is one of the most important factors to influence patients' access to TB care.

[p53 gene intron 7 polymorphism and its association with oral neoplasms].

OBJECTIVE: To investigate the association between oral neoplasm genetic susceptibility and genetic polymorphism of p53 intron 7. METHODS: The intron 7 ApaI polymorphism of p53 was analyzed in 95 oral neoplasm patients and 105 healthy individuals by utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genotyping assay technique, and direct sequencing was performed in 30 cases which were selected from the patients and controls by random sampling. RESULTS: In oral neoplasms cases, haplotype combinations were T-G 43.2%, C-T 56.8%, and frequencies of genotype were T-G/T-G 15.8%, C-T/T-G 54.7%, C-T/C-T 29.5%, while in controls they were T-G 30.9%, C-T 69.1% and T-G/T-G 10.5%, C-T/T-G 41.0%, C-T/C-T 48.5%. There was a significant difference in the allelic frequency and the genotypical distributions between the oral neoplasm patients and the controls. The individuals with the T-G allele had a slight increasing neoplasm risk than individuals with C-T allele; the OR for T-G versus C-T was 1.69 (95% CI, 1.12 - 2.51). The risk of suffering from oral neoplasms was higher in the individuals of T-G/T-G genotype and of T-G/C-T genotype than in individuals of C-T/CT genotype with odds ratio of 2.48 versus 2.20. CONCLUSIONS: There are two polymorphic points in the 7th intron of human p53 gene, which could be associated with genetic susceptibility of oral neoplasms. T-G allele may be the risk factor of oral neoplasms.