Association between CHRNA3 rs1051730 genotype and lung cancer risk in Chinese Han population: a case-control study.

Recent population-based genome wide association studies have revealed potential susceptibility loci of lung cancer at the region of chromosome 15q25.1 containing nicotinic acetylcholine receptor genes. The loci increasing lung cancer risk has been widely identified in Caucasians, but whether this association also exists in Asians and whether this association is a direct role or mediated via tobacco smoking indirectly has not been fully established. We conducted a case-control study comprising of 210 histologically confirmed lung cancer cases and 200 healthy controls to examine rs1051730 genotyping, a single nucleotide polymorphism receiving much attention recently, and its influence on lung cancer risk as well as nicotine dependence in a Chinese Han population. Our results showed that the heterozygous C/T genotype and minor allele T conferred a significant higher risk of lung cancer than the CC homozygotes and allele C (adjusted OR=2.25, 95% CI=1.04-4.89, P=0.040 and OR=2.18, 95% CI=1.02-4.67, P=0.045 respectively). However, no association between the smoking habit and the CHRNA3 rs1051730 polymorphism was observed in this study. The results suggested that the rs1051730 polymorphism may modify susceptibility to lung cancer via a smoking-independent manner among Chinese Han population. Additional studies in vitro and in vivo are warranted to further elucidate the impact of rs1051730 on lung cancer susceptibility.

Hypoxia-induced autophagy confers resistance of breast cancer cells to ionizing radiation.

Hypoxia is a hallmark of solid tumors, which presents a major obstacle to the effectiveness of radiation therapy. However, the function and the importance of molecular response have not been well defined. In the present study, hypoxia-induced autophagy and its effect on the response of breast cancer cells to ionizing radiation were examined. Results showed that hypoxic exposure induced a marked accumulation of autophagosomes accompanied by mRNA induction of the autophagy-related genes Beclin-1, Atg5, Atg7, and Atg12. The elevated autophagic activity was associated with increased radioresistance of tumor cells. Accordingly, blockade of autophagy by pharmacological inhibition or Beclin-1 small interfering RNA (siRNA) contributed to retardation of DNA double-strand breaks (DSB) repair and significant radiosensitization. Our data indicate that strategies designed to suppress autophagic activity may represent promising new therapies for sensitizing hypoxic breast cancer cells to ionizing radiation (IR).

[Growth of breast cancer cells is inhibited in vitro by cyclin E-siRNA].

OBJECTIVE: To investigate the changes of biological characteristics of breast cancer cell line by cyclin E expression. METHODS: Human breast cancer cell line MCF-7 was transfected with cyclin E siRNA vector pEGFP/CCNE2. siRNA-induced silencing of cyclin E was determined by RT-PCR at RNA level and Western blot at protein level. The proliferation of MCF-7 cells and their sensitivity to chemotherapy was measured by CCK-8 assay. The cells were examined by FCM. The cell line was injected into nude mice and the tumor size was measured. RESULTS: The expression of cyclin E was inhibited in the MCF-7 cells. The relative expression level of cyclin E mRNA was 0.23 +/- 0.05, and that of cyclin E protein was 0.24 +/- 0.05. The cell growth was inhibited by 68.56% +/- 0.08%, and their sensitivity to chemotherapy was increased. Most cells were blocked at G(1) (77.38%), their tumorigenic ability in nude mice was reduced, and the size of tumor formed in mice of the experimental group was decreased than that of controls. CONCLUSION: Inhibition of cyclin E expression in breast cancer cells can block their cell cycle at G(1) phase, reduce their cell growth, differentiation and proliferation, and increase their sensitivity to chemotherapy.

[Establishment of an I-SceI system and its application to introduce DNA double-strand break into human hepatoma cell line HepG2].

OBJECTIVE: To construct a system of I-SceI and induce a site-specific DNA double-strand break (DSB) in the genome of HepG2 for using this system in future exploration of the potential mechanisms of HBV integration by DSB repair. METHODS: The eukaryotic expression plasmid pEGFP2 was constructed and transfected into human hepatoma cell line HepG2. The positive neomycin-resistant transfected cell clones were generated by G418 selection. Then the positive cells containing an 18-bp I-SceI endonuclease site were transfected transiently with pCMV(3NLS) I-SceI, an I-SceI expression plasmid. At 24 h post-transfection with pCMV (3NLS) I-SceI, gamma-H2AX, as an early cellular marker of DSB, was detected using immunocytochemistry and Western blot analysis. RESULTS: Restriction analysis and DNA sequencing verified that the plasmid pEGFP2 was successfully constructed. gamma-H2AX increased significantly in cells transfected with the I-SceI system. CONCLUSIONS: Genomic DSB can be induced into HepG2 by introducing an I-SceI system. The cell model could provide us with a practical tool for further study to see if DSB is a potential target for HBV integration.

[Development and clinical application of male human papillomavirus genotyping by membrane DNA chip].

OBJECTIVE: To develop a new method for the detection of male human papillomavirus (HPV) genotypes and to investigate its clinical application value. METHODS: With computer assistance and based on the classical common primers MY09/11, modified PGMY09/11 with 23 HPV subtypes for PCR and Genbank data on HPV, we designed probes for the simultaneous detection of 18 high-risk subtypes (HPV-16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73, 83 and MM4) and 5 low-risk subtypes (HPV-6, 11, 42, 43 and 44) and fixed them to the special membrane to make a DNA chip. A total of 112 male urethral samples were collected with swabs and studied for the clinical value. Meanwhile the single subtypes of HPV positive were sequenced and the standard samples detected for their sensitivity. RESULTS: Of the total number, 25 samples were found to be HPV positive, 13 single HPV infection and 12 multiple infection. Nine HPV gene subtypes were noted in the samples: 6, 11, 16, 18, 33, 35, 43, 56 and 73, with sensitivity up to 10 copies of HPV DNA. CONCLUSION: Human papillomavirus genotyping by the membrane DNA chip is applicable to the diagnosis of male HPV infection as well as to the related epidemic and etiological investigation.

Relationship between expression of vascular endothelial growth factor and cervical lymph node metastasis in papillary thyroid cancer: A meta-analysis.

The aim of the present study was to examine the relationship between the protein expression of vascular endothelial growth factor (VEGF) and lymph node metastasis (LNM) in papillary thyroid cancer (PTC). VEGF-related articles that had been published until August 2016 were searched from the PubMed, EMBASE, and MEDLINE to identify the risk factors of LNM in PTC. RevMan 5.3 software was used for the meta-analysis. Finally, 9 articles met the inclusion criteria and were included in our meta-analysis. LNM was found to be present in 176 of 318 patients (57.8%) with high VEGF expression and in 71 of 159 patients (47.0%) with low VEGF expression. The overall OR was 2.81 (95% confidence interval, 1.49-5.29). LNM occurred more frequently in patients with high VEGF expression than in those with low VEGF expression (P=0.001). Heterogeneity was markedly decreased in the subgroup analyses of LNM in terms of the patients' country of origin and the detection methods. Our meta- analysis concluded that the VEGF protein expression is associated with LNM in PTC.

EGFR mutations in non-small-cell lung cancer among smokers and non-smokers: a meta-analysis.

Mounting evidence has suggested somatic mutations in the EGFR gene are associated with better responsiveness to EGFR tyrosine kinase inhibitors (TKIs) in patients with non-small-cell lung cancer (NSCLC). Some, but not all, studies have reported that the mutations were more frequently observed in patients without a smoking history. To comprehensively address this issue, we performed a meta-analysis to evaluate the association between cigarette-smoking history and mutation of the EGFR gene in NSCLC. Twenty-six studies, involving 3,688 patients with NSCLC were included in the analysis. The pooled analysis shows that the incidence of EGFR mutations in NSCLC differs according to cigarette-smoking history. The odds ratio (OR) for the EGFR mutation in non-smokers relative to smokers was 4.829 (95% confidence interval [CI]: 3.598-6.482; P < 0.001). These data may assist clinicians in assessing the likelihood of EGFR mutations in patients with NSCLC when mutational analysis is not feasible.

Acquired cisplatin resistance in human lung adenocarcinoma cells is associated with enhanced autophagy.

Activation of autophagy is a hallmark in tumor cells treated with chemotherapy, but the role of autophagy in acquired resistance of lung adenocarcinoma to cisplatin-based chemotherapy remains to be clarified. Our aim was to address that question by surveying the autophagic activity in parental lung adenocarcinoma cell line A549 and its 8-fold, more resistant subcell line, A549/DDP, which was obtained by treating cisplatin with increasing concentrations. A549/DDP and A549 cells were exposed to serum-free culture medium or ionizing radiation. To measure the stress-induced autophagy, LC3-II, as an autophagosome marker, was measured by immunofluorescence and Western blotting. To determine the effect of 3-MA, a known inhibitor of autophagy, on overcoming acquired cisplatin resistance, the MTT assay and flow cytometry were performed. Western blotting analysis demonstrated that LC3-II was increased in A549/DDP cells, compared with those of parental A549 cells, under stress conditions. Meanwhile, immunofluorescence staining showed that LC3-II protein was located mainly in the cytoplasm of A549/DDP. We also found that 3-MA can enhance the growth inhibition and apoptotic effect of cisplatin in acquired resistant cells (A549/DDP). Collectively, our results provide evidence that the upregulation of autophagy plays a major role in cisplatin resistance of A549/DDP cells.

[Seasonal and semi-lunar changes in fish community structure in low salinity intertidal area of Yangtze estuary].

Based on the survey of the fishes in low salinity intertidal area of the Yangtze estuary from spring (May) 2006 to winter (February) 2007, the seasonal and semi-lunar changes of fish species and abundances were analyzed. A total of 53 fish species were collected, most of which belonged to Cyprinidae, followed by Gobiidae, and few of other families. The fish species and average abundance were higher in spring, summer, and autumn than in winter and lower in low tides than in high tides in four seasons. Shannon-Weaver (H') value had a greater fluctuation in a tidal cycle, and was appreciably lower in low tides than in high tides. The fish species and abundance were clustered into two groups, i. e., that of winter, and of the other seasons. As for the whole year, the abundance had the highest positive correlation with water temperature, then with tide height, and lowest with water salinity.

[Succession character of salt marsh vegetations in Chongming Dongtan wetland].

This paper studied the ecological character, importance value, aboveground biomass and its N content of salt marsh vegetations in Chongming Dongtan wetland in the process of succession. The results indicated that with the increase of altitude, the importance value of Scirpus mariqueter, a representative species at early succession stage, decreased gradually, while those of Spartina alterniflora and Phragmites australis increased. The biodiversity of the vegetations increased with succession. During growth period (from March to October), the aboveground biomass of the three species varied in single hump curve, with the peak in July and August. The N content had a decreasing trend, while the N capacity showed a single-peak curve. The estimated annual N accumulation in aboveground biomass was 383.4 t for P. australis, 50.5 t for S. mariqueter, and 39. 3 t for S. alterniflora.