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author:("Feng, xinghua")
1.  Analysis of Tp53 Codon 72 Polymorphisms, Tp53 Mutations, and HPV Infection in Cutaneous Squamous Cell Carcinomas 
PLoS ONE  2012;7(4):e34422.
Background
Non-melanoma skin cancers are one of the most common human malignancies accounting for 2–3% of tumors in the US and represent a significant health burden. Epidemiology studies have implicated Tp53 mutations triggered by UV exposure, and human papilloma virus (HPV) infection to be significant causes of non-melanoma skin cancer. However, the relationship between Tp53 and cutaneous HPV infection is not well understood in skin cancers. In this study we assessed the association of HPV infection and Tp53 polymorphisms and mutations in lesional specimens with squamous cell carcinomas.
Methods
We studied 55 cases of histologically confirmed cutaneous squamous cell carcinoma and 41 controls for the presence of HPV infection and Tp53 genotype (mutations and polymorphism).
Results
We found an increased number of Tp53 mutations in the squamous cell carcinoma samples compared with perilesional or control samples. There was increased frequency of homozygous Tp53-72R polymorphism in cases with squamous cell carcinomas, while the Tp53-72P allele (Tp53-72R/P and Tp53-72P/P) was more frequent in normal control samples. Carcinoma samples positive for HPV showed a decreased frequency of Tp53 mutations compared to those without HPV infection. In addition, carcinoma samples with a Tp53-72P allele showed an increased incidence of Tp53 mutations in comparison carcinomas samples homozygous for Tp53-72R.
Conclusions
These studies suggest there are two separate pathways (HPV infection and Tp53 mutation) leading to cutaneous squamous cell carcinomas stratified by the Tp53 codon-72 polymorphism. The presence of a Tp53-72P allele is protective against cutaneous squamous cell carcinoma, and carcinoma specimens with Tp53-72P are more likely to have Tp53 mutations. In contrast Tp53-72R is a significant risk factor for cutaneous squamous cell carcinoma and is frequently associated with HPV infection instead of Tp53 mutations. Heterozygosity for Tp53-72R/P is protective against squamous cell carcinomas, possibly reflecting a requirement for both HPV infection and Tp53 mutations.
doi:10.1371/journal.pone.0034422
PMCID: PMC3335843  PMID: 22545084
2.  Expression of Mir-21 and Mir-143 in Cervical Specimens Ranging from Histologically Normal through to Invasive Cervical Cancer 
PLoS ONE  2011;6(12):e28423.
Background
MicroRNA expression is severely disrupted in carcinogenesis, however limited evidence is available validating results from cell-line models in human clinical cancer specimens. MicroRNA-21 (mir-21) and microRNA-143 (mir-143) have previously been identified as significantly deregulated in a range of cancers including cervical cancer. Our goal was to investigate the expression patterns of several well-studied microRNA species in cervical samples and compare the results to cell line samples.
Methodology/Principal Findings
We measured the expression of mir-21 and mir-143 in 142 formalin-fixed, paraffin embedded (FFPE) cervical biopsy tissue blocks, collected from Dantec Oncology Clinic, Dakar, Senegal. MicroRNA expression analysis was performed using Taqman-based real-time PCR assays. Protein immunohistochemical staining was also performed to investigate target protein expression on 72 samples. We found that mir-21 expression increased with worsening clinical diagnosis but that mir-143 was not correlated with histology. These observations were in stark contrast to previous reports involving cervical cancer cell lines in which mir-143 was consistently down-regulated but mir-21 largely unaffected. We also identified, for the first time, that cytoplasmic expression of Programmed Cell Death Protein 4 PDCD4; a known target of mir-21) was significantly lower in women with invasive cervical carcinoma (ICC) in comparison to those with cervical intraepithelial neoplasia (2–3) or carcinoma in situ (CIN2-3/CIS), although there was no significant correlation between mir-21 and PDCD4 expression, despite previous studies identifying PDCD4 transcript as a known mir-21 target.
Conclusions
Whilst microRNA biomarkers have a number of promising features, more studies on expression levels in histologically defined clinical specimens are required to investigate clinical relevance of discovery-based studies. Mir-21 may be of some utility in predictive screening, given that we observed a significant correlation between mir-21 expression level and worsening histological diagnosis of cervical cancer.
doi:10.1371/journal.pone.0028423
PMCID: PMC3237431  PMID: 22194833
3.  DNA hypermethylation of tumors from non-small cell lung cancer (NSCLC) patients is associated with gender and histologic type 
Background
We previously identified a number of genes which were methylated significantly more frequently in the tumor compared to the non-cancerous lung tissues from non-small cell lung cancer (NSCLC) patients. Detection of methylation profiles of genes in NSCLC could provide insight into differential pathways to malignancy and lead to strategies for better treatment of individuals with NSCLC.
Methods
We determined the DNA methylation status of 27 genes using quantitative MethyLight assays in lung tumor samples from 117 clinically well-characterized NSCLC patients.
Results
Hypermethylation was detected in one of more of the genes in 106 (91%) of 117 cases and was detected at high levels (Percentage of Methylation Reference (PMR)≥4%) in 79% of NSCLC cases. Methylation of APC, CCND2, KCNH5 and, RUNX was significantly more frequent in adenocarcinomas compared to squamous cell carcinomas (SCC), while methylation of CDKN2A was more common in SCC. Hypermethylation of KCNH5, KCNH8, and RARB was more frequent in females compared to males. Hypermethylation of APC and CCND2 was inversely associated with proliferation score assessed by Ki-67 level.
Conclusions
Our findings of differential gene hypermethylation frequencies in tumor tissues from patients with adenocarcinoma or squamous cell cancers and in females compared to males suggests that further investigation is warranted in order to more fully understand the potential disparate pathways and/or risk factors for NSCLC associated with histologic type and gender.
doi:10.1016/j.lungcan.2009.11.002
PMCID: PMC2888601  PMID: 19945765
hypermethylation; lung cancer; gender; histology
4.  Hypermethylation of CCND2 May Reflect a Smoking-Induced Precancerous Change in the Lung 
Journal of Oncology  2011;2011:950140.
It remains unknown whether tobacco smoke induces DNA hypermethylation as an early event in carcinogenesis or as a late event, specific to overt cancer tissue. Using MethyLight assays, we analyzed 316 lung tissue samples from 151 cancer-free subjects (121 ever-smokers and 30 never-smokers) for hypermethylation of 19 genes previously observed to be hypermethylated in nonsmall cell lung cancers. Only APC (39%), CCND2 (21%), CDH1 (7%), and RARB (4%) were hypermethylated in >2% of these cancer-free subjects. CCND2 was hypermethylated more frequently in ever-smokers (26%) than in never-smokers (3%). CCND2 hypermethylation was also associated with increased age and upper lobe sample location. APC was frequently hypermethylated in both ever-smokers (41%) and never-smokers (30%). BVES, CDH13, CDKN2A (p16), CDKN2B, DAPK1, IGFBP3, IGSF4, KCNH5, KCNH8, MGMT, OPCML, PCSK6, RASSF1, RUNX, and TMS1 were rarely hypermethylated (<2%) in all subjects. Hypermethylation of CCND2 may reflect a smoking-induced precancerous change in the lung.
doi:10.1155/2011/950140
PMCID: PMC3090638  PMID: 21577262
5.  Evaluation of Transported Dry and Wet Cervical Exfoliated Samples for Detection of Human Papillomavirus Infection▿  
Journal of Clinical Microbiology  2010;48(9):3068-3072.
We determined the feasibility of human papillomavirus (HPV) detection in cervical exfoliated cells collected as dry swab samples. Both dry cervical swab and specimen transport medium (STM) cervical swab samples were collected from 135 patients attending either colposcopy or women's clinics in Guayaquil, Ecuador, who had a cytology diagnosis within 6 months. HPV was detected by dot blot hybridization and genotyped by the liquid bead microarray assay (LBMA). Overall, 23.1% of dry samples were positive for any high-risk HPV types, and 24.6% of STM samples were positive for any high-risk HPV types. Of 125 paired samples, the type-specific high-risk HPV proportion positive agreement was 60.7% (kappa, 0.69; 95% confidence interval [CI], 0.53 to 0.82). Of six women with cytological evidence of invasive cervical cancer, high-risk HPV DNA was detected in three of their STM samples and in five of their dry samples. Dry samples were more likely to be insufficient for HPV testing than STM samples. Consistent with this observation, the amount of genomic DNA quantitated with the β-actin gene was almost 20 times lower in dry samples than in STM samples when detected by the real-time TaqMan assay; however, HPV DNA viral loads in dry samples were only 1.6 times lower than those in matched STM samples. We concluded that exfoliated cervical cells could be collected as dry swab samples for HPV detection.
doi:10.1128/JCM.00736-10
PMCID: PMC2937663  PMID: 20610686
6.  DNA Methylation in Tumor and Matched Normal Tissues from Non-Small Cell Lung Cancer Patients 
We used MethyLight assays to analyze DNA methylation status of 27 genes on 49 paired cancerous and noncancerous tissue samples from non-small cell lung cancer (NSCLC) patients who underwent surgical resection. Seven genes (RARB, BVES, CDKN2A, KCNH5, RASSF1, CDH13, and RUNX) were found to be methylated significantly more frequently in tumor tissues than in noncancerous tissues. Only methylation of CCND2 and APC was frequently detected in both cancerous and noncancerous tissues, supporting the hypothesis that the methylation of these two genes is a preneoplastic change and may be associated with tobacco smoking exposure. Methylation of any one of eight genes (RASSF1, DAPK1, BVES, CDH13, MGMT, KCNH5, RARB, or CDH1) was present in 80% of NSCLC tissues but only in 14% of noncancerous tissues. Detection of methylation of these genes in blood might have utility in monitoring and detecting tumor recurrence in early-stage NSCLC after curative surgical resection.
doi:10.1158/1055-9965.EPI-07-2518
PMCID: PMC2798850  PMID: 18349282
7.  DNA Hypermethylation, Her-2/neu Overexpression and p53 Mutations in Ovarian Carcinoma 
Gynecologic oncology  2008;111(2):320-329.
Objectives
To define patterns of aberrant DNA methylation, p53 mutation and Her-2/neu overexpression in tissues from benign (N=29), malignant (N=100), and border line malignant ovaries (N=10), as compared to normal (N=68) ovarian tissues. Further, to explore the relationship between the presence of genetic and epigenetic abnormalities in ovarian cancers, and assess the association between epigenetic changes and clinical stage of malignancy at presentation and response to therapy.
Methods
The methylation status of 23 genes that were previously reported associated with various epithelial malignancies was assessed in normal and abnormal ovarian tissues by methylation specific PCR. The presence of p53 mutation (N=82 cases) and Her-2/neu overexpression (N=51 cases) were assessed by DNA sequencing and immunohistochemistry, respectively.
Results
Methylation of four genes (MINT31, HIC1, RASSF1, and CABIN1) was significantly associated with ovarian cancer but not other ovarian pathology. Her-2/neu overexpression was associated with aberrant methylation of three genes (MINT31, RASSF1, and CDH13), although aberrant methylation was not associated with p53 mutations. Methylation of RASSF1 and HIC1 was more frequent in early compared to late stage ovarian cancer, while methylation of CABIN1 and RASSF1 was associated with response to chemotherapy.
Conclusion
DNA methylation of tumor suppressor genes is a frequent event in ovarian cancer, and in some cases is associated with Her-2/neu overexpression. Methylation of CABIN1 and RASSF1 may have the utility to predict response to therapy.
doi:10.1016/j.ygyno.2008.07.036
PMCID: PMC2642648  PMID: 18757082
hypermethylation; Her-2/neu overexpression; p53; ovarian cancer
8.  Development and Evaluation of a Liquid Bead Microarray Assay for Genotyping Genital Human Papillomaviruses▿ †  
Journal of Clinical Microbiology  2009;47(3):547-553.
We developed a liquid bead microarray (LBMA) assay for genotyping genital human papillomaviruses (HPVs) based on the MY09-MY11-HMB01 PCR system and the reverse line blot (RLB) assay probe sequences. Using individual HPV plasmids, we were able to detect as few as 50 copies per reaction. In two separate retrospective studies, the LBMA assay was compared to the RLB assay and to the Hybrid Capture II (hc2) assay. Testing was performed without knowledge of other assay results. In the first study, 614 cervical swab samples (enriched for HPV infection) from 160 young women were tested for HPV DNA, and 360 (74.8%) type-specific HPV infections were detected by both assays, 71 (14.8%) by the LBMA assay only, and 50 (10.4%) by the RLB assay only. Type-specific agreement for the two assays was excellent (99.1%; kappa = 0.85; 95% confidence interval [95% CI], 0.82 to 0.88). Samples with discrepant LBMA and RLB test results tended to have low viral loads by a quantitative type-specific PCR assay. In the second study, cervical swab samples from 452 women (including 54 women with histologically confirmed cervical-intraepithelial neoplasia grade 2 or worse [≥CIN2]) were tested initially by the hc2 and subsequently by the LBMA assay. The estimated sensitivities for ≥CIN2 were similar for the LBMA and hc2 assays (98.4% [95% CI, 95.0 to 100%] and 95.6% [95% CI, 89.2 to 100%], respectively). The percentages of negative results among 398 women without ≥CIN2 were similar for the LBMA and hc2 assays (45% and 50%, respectively). The repeat test reproducibility for 100 samples was 99.1% (kappa = 0.92; 95% CI, 0.90 to 0.95). We conclude that the new LBMA assay will be useful for clinical and epidemiological research.
doi:10.1128/JCM.01707-08
PMCID: PMC2650937  PMID: 19144800
9.  Expression of Mammaglobin, B305D, GABAπ and B726P and elevation of Mammaglobin protein in the peripheral blood of women with untreated breast cancers 
Clinical chemistry  2004;50(11):2069-2076.
Purpose
The aim of this study was to analyze the utility of a mammaglobin multigene RT-PCR assay and a mammaglobin sandwich ELISA to detect peripheral blood samples of breast cancer patients.
Experimental Design
Peripheral blood samples of 147 untreated Senegalese women with biopsy confirmed breast cancer were collected. The samples were tested for mammaglobin and 3 breast cancer associated gene transcripts using a multigene real-time RT-PCR assay and for secreted mammaglobin protein using a sandwich ELISA format. Patient information regarding demographic and clinical staging of disease was also collected.
Results
In 77 % of the breast cancer blood samples a positive expression signal was found using the multigene RT-PCR assay detecting mammaglobin and three complementary transcribed genes. 50 samples from healthy female donors tested negative. Circulating mammaglobin protein was found in 68 % of the breast cancer sera, whereas 38 % showed significantly elevated protein levels in comparison to a mixed control population. Statistical correlations were found between the detection of mammaglobin protein in serum, presence of mammaglobin mRNA expressing cells in blood, stage of disease and tumor size.
Conclusions
The multigene mammaglobin RT-PCR assay and mammaglobin sandwich ELISA could be valuable tools to detect metastatic disease and to monitor therapeutic efficiency. Both assays together provided a diagnostic sensitivity of 83 %. Use of the multigene RT-PCR increased detection sensitivity from 61 to 77 % in comparison to mammaglobin expression alone.
doi:10.1373/clinchem.2004.038687
PMCID: PMC1482781  PMID: 15375015
multigene RT-PCR; circulating tumor cell detection; breast cancer

Results 1-9 (9)