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Guiyang Jiang,
Chuifeng Fan,
Xiupeng Zhang,
Qianze Dong,
Liang Wang,
Yang Liu,
Shundong Dai, Lianhe Yang,
Yong Zhang,
Juanhan Yu,
Enhua Wang
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ABSTRACT: Epidermal growth factor receptor (EGFR) mutation status is the most valuable indicator in the screening of non-small-cell lung cancer (NSCLC) patients for tyrosine kinase inhibitor (TKI) therapy. Accurate, rapid and economical methods of detecting EGFR mutations have become important. The use of two mutation-specific antibodies targeting the delE746-A750 mutation in exon 19 and L858R mutation in exon 21 makes this task possible, but the lack of consensually acceptable criteria for positive results limits the application of this antibody based mutation detection.
We collected 399 specimens from NSCLC patients (145 resection specimens, 220 biopsy specimens, and 34 cytology specimens) whose EGFR mutation status had been detected by TaqMan PCR assay. Immunohistochemical (IHC) analyses using EGFR mutation-specific antibodies were employed for all samples. After staining and scoring, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated in accordance with different levels of positive grades in comparison with the results of PCR-based assay.
In IHC-based analyses, 144 cases were scored 0, 104 cases were scored 1+, 103 cases were scored 2+, and 48 cases were scored 3+. With the molecular-based results were set as the "gold standard", the prevalence of mutation was 6.94% (10/144), 23.08% (24/104), 67.96% (70/103) and 100% (48/48), respectively, for samples with scores 0, 1+, 2+ and 3+. When score 3+ was considered positive, the specificity and PPV were 100%; if only score 0 was considered negative, 93.06% NPV was obtained.
Patients with score 3+ have a perfect PPV (100%), and may accept TKI treatment directly without any molecular-based assays. Patients with score 0 had high NPV (93.06%), which could reach 97.22% when the detection of total EGFR was applied. However, samples with score 1+ or 2+ are unreliable and need further verification of EGFR mutation status by molecular-based assays.
PLoS ONE 01/2013; 8(3):e59183. · 4.09 Impact Factor
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ABSTRACT: Developing polyamine conjugates having the potential of transporting naphthalimide selectively into tumor cells is attractive. However, the evaluation of their cytotoxic mechanism has not been comprehensive. This study focused on the effects of mononaphthalimide spermidine (MNISpd) conjugate on apoptosis induction and the relationship between MNISpd-induced apoptosis and reactive oxygen species (ROS) in HeLa cells. Our findings indicated that 9 µM MNISpd induced apoptosis in HeLa cells during a 48-h period. MNISpd induced apoptosis in HeLa cells following cytochrome c release, elevation of caspase 3/9 activity, apoptosis-inducing factor (AIF) translocation and up-/down-regulation of Bax/Bcl-2 protein expression, respectively, and these effects were completely antagonized by pre-incubation with 10 mM NAC for 2 h. MNISpd induced significant ROS accumulation following up-regulation of polyamine oxidase (PAO) activity and complex variations in glutathione levels. It is concluded that MNISpd-induced apoptosis is related to intrinsic caspase-dependent and AIF-mediated caspase-independent apoptosis pathways in HeLa cells. MNISpd-induced apoptosis correlates to MNISpd-induced ROS production resulting from GSH (reduced form of glutathione) pool depletion, and PAO is likely to be the source of ROS.
Oncology Reports 02/2011; 25(4):1099-107. · 1.84 Impact Factor
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ABSTRACT: Developing polyamine-drug conjugates that are capable of specific entry to tumor cells is attractive in improving chemotherapeutic efficacy. Currently, the exact cytotoxic mechanism of these conjugates is not well known. Here, our research revealed the effect of a mononaphthalimide-spermidine (MNISpd) conjugate on the growth and survival of HeLa cells and possible mechanisms. In characterizing the mechanism of MNISpd cytotoxicity, inhibition of proliferation is observed in the 0.5-6 μM range and there is evidence of apoptosis at equal or greater than 6 μM, but with less toxicity on HELF cell. The lower concentrations of MNISpd induced a cell cycle arrest correlated with enhanced p21 expression and decreased cdc2 but not Cdk2 expression. MNISpd-induced apoptosis was correlated with caspase-3 activation, decreased XIAP expression and a loss of mitochondrial membrane potential. Apoptosis but not cell cycle arrest was susceptible to N-acetyl-L-cysteine (NAC) treatment. It is proposed that MNISpd-induced apoptosis in HeLa cells is related to oxidative stress and that at lower exposure concentrations effects on cell proliferation predominate while at higher concentrations apoptosis develops.
Toxicology in Vitro 02/2011; 25(4):882-9. · 2.78 Impact Factor
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ABSTRACT: Axin is an important negative regulator of Wnt signaling pathway. It can induce the phosphorylation and degradation of beta-catenin. The reduced expression of axin or high expression of beta-catenin and TCF-4 were associated with malignant proliferation in many tumors. The aim of this study is to examine the relationships among the expressions and locations of axin, beta-catenin and other relevant molecules, and the roles of axin on proliferation, invasive ability and apoptosis of lung cancer cells.
The axin cDNA was transfected into lung cancer BE1 cell line which has very low axin expression. The levels of expression and location of axin, beta-catenin and TCF-4 before and after transfection were detected using immunofluorescence. The mRNA levels of expression of axin, beta-catenin and TCF-4 were examined using reverse transcription-polymerase chain reaction (RT-PCR). The apoptosis, proliferation and invasive ability of lung cancer cells before and after transfection were examined with flow cytometry, MTT and transwell methods.
After transfection of axin gene into BE1 cells (BE1-axin cells), axin mRNA and protein were overexpressed significantly. Meanwhile, the protein expression of beta-catenin and mRNA expression of TCF-4 were decreased significantly in BE1-axin cells than that in BE1 or vector control cells. The flow cytometry revealed that the apoptosis rate of BE1-axin cells was enhanced, but MTT and Transwell assay indicated that the proliferation and invasive ability were decreased significantly in BE1-axin cells than those in BE1 or vector control cells.
The overexpression of axin could down-regulate the protein expression of beta-catenin and the transcription of TCF-4, and inhibit the proliferation and invasive ability of lung cancer cells.
Zhongguo fei ai za zhi = Chinese journal of lung cancer 04/2009; 12(4):277-82.
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Lianhe Yang,
Hongtao Xu,
Yan Wang,
Yang Liu,
Yue Zhao,
Shundong Dai,
Qiang Wei,
Yuan Miao,
Yang Han,
Zhiqiang Yang,
Nan Liu,
Enhua Wang
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ABSTRACT: TCF-4 is an important downstream molecule of Wnt signaling pathway, but studies on the expression level and significance of TCF-4 in lung cancer were still limited. The aim of this study is to examine the expression level of TCF-4 in lung cancer tissues and cell lines, and analyze its relationship with clinicopathologic characteristics and biological behavior of lung cancers.
TCF-4 expression was examined in 120 lung cancer specimens and 10 corresponding normal lung specimens using immunohistochemistry (S-P method). Immunofluorescence was used to examine the TCF-4 protein expression level and subcellular localization in lung cancer cells and HBE (human normal bronchi epithelium) cells. Expression levels of TCF-4 mRNA were examined using transcription-polymerase chain reaction (RT-PCR) in 9 lung cancer cell lines.
Among 120 lung cancer specimens, 96 samples showed high expression of TCF-4 (80.0%), including 37 samples showed TCF-4 expression both in cytoplasm and nuclei (30.8%),TCF-4 were not detected in 10 corresponding normal lung specimens. TCF-4 expression level was positively correlated with TNM stages (P =0.022). The fluorescence signal of TCF-4 protein was conspicuous in lung cancer cells, primarily in cell nuclei, but extremely low in HBE. TCF-4 mRNA expression levels were incompatible in different histology types, the expression level of TCF-4 was relatively high in giant cell carcinoma cells, but low in lung adencarcinoma cells.
High expression of TCF-4 positively correlated with lung cancer progression.
Zhongguo fei ai za zhi = Chinese journal of lung cancer 04/2008; 11(2):214-9.
