Biomedical subjects

Nan Hu

Publications and source records attributed to Nan Hu.

At least 19 recordsLinked to original sources

PubMed2006

Tissue microarray analysis reveals a tight correlation between protein expression pattern and progression of esophageal squamous cell carcinoma.

BACKGROUND: The development of esophageal squamous cell carcinoma (ESCC) progresses a multistage process, collectively known as precursor lesions, also called dysplasia (DYS) and carcinoma in situ (CIS), subsequent invasive lesions and final metastasis. In this study, we are interested in investigating the expression of a variety of functional classes of proteins in ESCC and its precursor lesions and characterizing the correlation of these proteins with ESCC malignant progression. METHODS: Fas, FADD, caspase 8, CDC25B, fascin, CK14, CK4, annexin I, laminin-5gamma2 and SPARC were analyzed using immunohistochemistry on tissue microarray containing 205 ESCC and 173 adjacent precursor lesions as well as corresponding normal mucosa. To confirm the immunohistochemical results, three proteins, fascin, CK14 and laminin-5gamma2, which were overexpressed in ESCC on tissue microarray, were detected in 12 ESCC cell lines by Western blot assay. RESULTS: In ESCC and its precursor lesions, FADD, CDC25B, fascin, CK14, laminin-5gamma2 and SPARC were overexpressed, while Fas, caspase 8, CK4 and annexin I were underexpressed. The abnormalities of these proteins could be classified into different groups in relation to the stages of ESCC development. They were "early" corresponding to mild and moderate DYS with overexpression of fascin, FADD and CDC25B and underexpression of Fas, caspase 8, CK4 and annexin I, "intermediate" to severe DYS and CIS with overexpression of FADD and CK14, and "late" to invasive lesions (ESCC) and to advanced pTNM stage ESCC lesions with overexpression of CK14, laminin-5gamma2 and SPARC. CONCLUSION: Analyzing the protein expression patterns of Fas, FADD, caspase 8, CDC25B, fascin, CK14, CK4, annexin I, laminin-5gamma2 and SPARC would be valuable to develop rational strategies for early detection of lesions at risk in advance as well as for prevention and treatment of ESCC.

Adult↗

PubMed2006

Key genes involved in heavy-metal resistance in Pseudomonas putida CD2.

A cadmium-resistant bacterium Pseudomonas putida CD2 was isolated from sewage sludge samples. Strain CD2 exhibited high maximal tolerant concentrations (MTC) for a large spectrum of divalent metals. Screening a library obtained using Tn5-B21 insertion mutagenesis resulted in identification of 12 mutants with a substantial decrease in resistance to 3 mM cadmium. The DNA sequences of the contiguous region from the Tn5 insertion sites were determined by inverse PCR. Six genes involved in cadmium resistance were identified. These genes were from three gene clusters: czcCBA1, cadA2R and colRS. The homologs of the first two gene clusters were predicted to be metal efflux systems, whereas the products of colRS, ColR and ColS, were thought to be a two-component signal transduction (TCST) system. In this study, we have demonstrated that ColRS also function in regulating multi-metal resistance using genetic complementation.

Anti-Bacterial Agents↗

PubMed2006

Genome-wide loss of heterozygosity and copy number alteration in esophageal squamous cell carcinoma using the Affymetrix GeneChip Mapping 10 K array.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a common malignancy worldwide. Comprehensive genomic characterization of ESCC will further our understanding of the carcinogenesis process in this disease. RESULTS: Genome-wide detection of chromosomal changes was performed using the Affymetrix GeneChip 10 K single nucleotide polymorphism (SNP) array, including loss of heterozygosity (LOH) and copy number alterations (CNA), for 26 pairs of matched germ-line and micro-dissected tumor DNA samples. LOH regions were identified by two methods--using Affymetrix's genotype call software and using Affymetrix's copy number alteration tool (CNAT) software--and both approaches yielded similar results. Non-random LOH regions were found on 10 chromosomal arms (in decreasing order of frequency: 17p, 9p, 9q, 13q, 17q, 4q, 4p, 3p, 15q, and 5q), including 20 novel LOH regions (10 kb to 4.26 Mb). Fifteen CNA-loss regions (200 kb to 4.3 Mb) and 36 CNA-gain regions (200 kb to 9.3 Mb) were also identified. CONCLUSION: These studies demonstrate that the Affymetrix 10 K SNP chip is a valid platform to integrate analyses of LOH and CNA. The comprehensive knowledge gained from this analysis will enable improved strategies to prevent, diagnose, and treat ESCC.

Aged↗

PubMed2006

Common cancer biomarkers.

There is an increasing interest in complementing conventional histopathologic evaluation with molecular tools that could increase the sensitivity and specificity of cancer staging for diagnostic and prognostic purposes. This study strove to identify cancer-specific markers for the molecular detection of a broad range of cancer types. We used 373 archival samples inclusive of normal tissues of various lineages and benign or malignant tumors (predominantly colon, melanoma, ovarian, and esophageal cancers). All samples were processed identically and cohybridized with an identical reference RNA source to a custom-made cDNA array platform. The database was split into training (n = 201) and comparable prediction (n = 172) sets. Leave-one-out cross-validation and gene pairing analysis identified putative cancer biomarkers overexpressed by malignant lesions independent of tissue of derivation. In particular, seven gene pairs were identified with high predictive power (87%) in segregating malignant from benign lesions. Receiver operator characteristic curves based on the same genes could segregate malignant from benign tissues with 94% accuracy. The relevance of this study rests on the identification of a restricted number of biomarkers ubiquitously expressed by cancers of distinct histology. This has not been done before. These biomarkers could be used broadly to increase the sensitivity and accuracy of cancer staging and early detection of locoregional or systemic recurrence. Their selective expression by cancerous compared with paired normal tissues suggests an association with the oncogenic process resulting in stable expression during disease progression when the presently used differentiation markers are unreliable.

Biomarkers, Tumor↗

PubMed2006

Structural analysis of an alkali-extractable polysaccharide from the seeds of Retama raetamssp. gussonei.

An alkali-extractable polysaccharide (1) was isolated from the seeds of Retama raetam ssp. gussonei. Its composition and linkage determination have been investigated using component analysis, methylation analysis, hydrolysis studies, and NMR spectroscopic analysis. This was shown to contain d-xylose, d-glucose, and 4-O-methyl-d-glucuronic acid in a molar ratio of 7:2:1 and consisted of a backbone of beta-(1-->4)-linked d-xylopyranosyl residues, having branches of alpha-d-glucopyranosyl residues that contain (1-->2)-linkages and 4-O-methyl-alpha-d-glucopyranosyluronic acid at O-2. This is the first report on the isolation of an alkali-extractable polysaccharide from this plant.

Endo-1,4-beta Xylanases↗

PubMed2006

Lower extremity strength and power are associated with 400-meter walk time in older adults: The InCHIANTI study.

BACKGROUND: It has been suggested that lower extremity muscle power is more important for physical function in older adults compared to strength, and that there is a nonlinear relationship between power or strength and physical function that might be indicative of a threshold above which the association between muscle function and physical function is no longer evident. This study examined the association between lower extremity strength or power with the time to complete a 400-meter walk, and attempted to identify thresholds within the relationship. METHODS: A cross-sectional analysis of a sample of 384 females and 336 males aged > or = 65 years from the InCHIANTI study ("Invecchiare in Chianti," i.e., Aging in the Chianti Area) was conducted. Measures included 400-meter walk time, lower extremity strength and power, comorbidities, and sociodemographic variables (age, gender, height, education, cognitive function, depression). RESULTS: Linear regression models showed that both lower extremity strength and power were significant predictors of 400-meter walk time, although power explained marginally more of the variance in 400-meter walk time. Quadratic models of lower extremity strength and power fit the data slightly better than the linear models. Regardless of gender, comorbidities, or normalization scheme for strength and power, the curvilinear form of the relationship between strength or power and 400-meter walk time remained the same. CONCLUSIONS: Lower extremity muscle strength and power are both important predictors of the 400-meter walk time. Although curvilinear relationships existed between muscle strength and power and the 400-meter walk time, the data do not indicate a clear threshold for either strength or power above which the performance in the 400-meter walk test plateaus.

Aged↗

PubMed2006

A multiplex tissue immunoblotting assay for proteomic profiling: a pilot study of the normal to tumor transition of esophageal squamous cell carcinoma.

Esophageal cancer remains a highly lethal malignancy for which the genetic and proteomic events are poorly understood. Studies have reported dysregulated proteins in esophageal carcinoma; however, the magnitude of these changes remains largely uncharacterized. Little is known about alterations early in the neoplastic pathway. Using multiplex tissue immunoblotting, we quantified the expression of seven proteins in esophageal carcinogenesis. Regions of normal, dysplasia, and invasive carcinoma of the squamous esophagus in six patients were characterized. Pan-cytokeratin (CK) was essentially unchanged across the transition (0.96 in dysplasia and 0.69 in tumor). Expression levels of annexin 1, CK-4, and CK-14 were all decreased in dysplasia and tumor compared with normal (reference, 1.00): annexin 1, 0.30 in dysplasia and 0.15 in tumor; CK-4, 0.20 in dysplasia and 0.16 in tumor; and CK-14, 0.54 in dysplasia and 0.40 in tumor. Expression of two proteins was increased in dysplasia and tumor versus normal: cyclooxygenase-2, 1.35 in dysplasia and 2.32 in tumor and p53, 1.29 in dysplasia and 2.37 in tumor. Secreted protein, acidic and rich in cysteine, which is expressed in the adjacent stroma, was 1.56-fold higher in stroma underlying dysplasia and 6.20-fold increased in dysplastic stroma surrounding invasive tumor. These findings suggest that changes in protein expression can be detected during the transition to dysplasia and may be useful biomarkers.

Biomarkers, Tumor↗

PubMed2006

p16, MGMT, RARbeta2, CLDN3, CRBP and MT1G gene methylation in esophageal squamous cell carcinoma and its precursor lesions.

Esophageal squamous cell carcinoma (ESCC) is a common cancer with a very poor prognosis. New methods are needed to screen high-risk populations and identify curable tumors and precursor lesions early. Molecular markers may be useful in such screening efforts. This study was designed to determine the prevalence of p16, MGMT, RARbeta2, CLDN3, CRBP and MT1G gene methylation in patients with ESCC to evaluate the variation of gene methylation across a spectrum of preneoplastic lesions, and assess the feasibility of using gene methylation in a primary screening test utilizing frozen esophageal cells collected by balloon cytology samplers. Samples were obtained from high-risk subjects from north central China. These samples included 11 foci of histologically normal mucosa, 8 foci of low-grade squamous dysplasia, 7 foci of high-grade squamous dysplasia, and 13 foci of ESCC from 6 fully embedded resection specimens; endoscopic biopsies from 6 individuals with no histological evidence of disease; and frozen esophageal balloon samples from 12 asymptomatic subjects. Promoter CpG site-specific hypermethylation status was determined for each gene using real-time methylation-specific PCR (qMS-PCR) based on Taqman chemistry. Of the 6 ESCC patients, 5 showed methylation of at least one gene. For most genes, methylation occurred with increasing frequency during neoplastic progression, with the largest increase found between low- and high-grade dysplasia. There was considerable variation in methylation patterns among different foci of the same histological grade, even within individual patients, but 16/20 (80%) of high-grade dysplastic and cancer foci had >or= 2 methylated genes, while 17/19 (89%) of normal and low-grade dysplastic foci had <2 methylated genes. These genes were rarely methylated in histologically normal mucosa from patients with or without ESCC. Gene methylation was common and easily detectable in the frozen esophageal cells collected by balloon cytology samplers. Our data suggest that methylation of p16, MGMT, RARbeta2, CLDN3, CRBP, and MT1G is common in the esophageal mucosa of patients with ESCC in this high-risk population, and tends to increase in prevalence in foci with increasing histological severity of disease. Methylation data from panels of genes may be able to identify patients with high-grade lesions. Balloon cytology may be able to screen the length of the esophagus effectively for a subset of cells with abnormal methylation, and may be useful in a primary screening test for ESCC and its precursor lesions.

Adult↗

PubMed2005

Decision forest analysis of 61 single nucleotide polymorphisms in a case-control study of esophageal cancer; a novel method.

BACKGROUND: Systematic evaluation and study of single nucleotide polymorphisms (SNPs) made possible by high throughput genotyping technologies and bioinformatics promises to provide breakthroughs in the understanding of complex diseases. Understanding how the millions of SNPs in the human genome are involved in conferring susceptibility or resistance to disease, or in rendering a drug efficacious or toxic in the individual is a major goal of the relatively new fields of pharmacogenomics. Esophageal squamous cell carcinoma is a high-mortality cancer with complex etiology and progression involving both genetic and environmental factors. We examined the association between esophageal cancer risk and patterns of 61 SNPs in a case-control study for a population from Shanxi Province in North Central China that has among the highest rates of esophageal squamous cell carcinoma in the world. METHODS: High-throughput Masscode mass spectrometry genotyping was done on genomic DNA from 574 individuals (394 cases and 180 age-frequency matched controls). SNPs were chosen from among genes involving DNA repair enzymes, and Phase I and Phase II enzymes. We developed a novel adaptation of the Decision Forest pattern recognition method named Decision Forest for SNPs (DF-SNPs). The method was designated to analyze the SNP data. RESULTS: The classifier in separating the cases from the controls developed with DF-SNPs gave concordance, sensitivity and specificity, of 94.7%, 99.0% and 85.1%, respectively; suggesting its usefulness for hypothesizing what SNPs or combinations of SNPs could be involved in susceptibility to esophageal cancer. Importantly, the DF-SNPs algorithm incorporated a randomization test for assessing the relevance (or importance) of individual SNPs, SNP types (Homozygous common, heterozygous and homozygous variant) and patterns of SNP types (SNP patterns) that differentiate cases from controls. For example, we found that the different genotypes of SNP GADD45B E1122 are all associated with cancer risk. CONCLUSION: The DF-SNPs method can be used to differentiate esophageal squamous cell carcinoma cases from controls based on individual SNPs, SNP types and SNP patterns. The method could be useful to identify potential biomarkers from the SNP data and complement existing methods for genotype analyses.

Algorithms↗

PubMed2005

Hox-controlled reorganisation of intrasegmental patterning cues underlies Drosophila posterior spiracle organogenesis.

Hox proteins provide axial positional information and control segment morphology in development and evolution. Yet how they specify morphological traits that confer segment identity and how axial positional information interferes with intrasegmental patterning cues during organogenesis remain poorly understood. We have investigated the control of Drosophila posterior spiracle morphogenesis, a segment-specific structure that forms under Abdominal-B (AbdB) Hox control in the eighth abdominal segment (A8). We show that the Hedgehog (Hh), Wingless (Wg) and Epidermal Growth Factor Receptor (Egfr) pathways provide specific inputs for posterior spiracle morphogenesis and act in a genetic network made of multiple and rapidly evolving Hox/signalling interplays. A major function of AbdB during posterior spiracle organogenesis is to reset A8 intrasegmental patterning cues, first by reshaping wg and rhomboid expression patterns, then by reallocating the Hh signal and later by initiating de novo expression of the posterior compartment gene engrailed in anterior compartment cells. These changes in expression patterns confer axial specificity to otherwise reiteratively used segmental patterning cues, linking intrasegmental polarity and acquisition of segment identity.

Animals↗

PubMed2005

Genome-wide association study in esophageal cancer using GeneChip mapping 10K array.

Whole genome association studies of complex human diseases represent a new paradigm in the postgenomic era. In this study, we report application of the Affymetrix, Inc. (Santa Clara, CA) high-density single nucleotide polymorphism (SNP) array containing 11,555 SNPs in a pilot case-control study of esophageal squamous cell carcinoma (ESCC) that included the analysis of germ line samples from 50 ESCC patients and 50 matched controls. The average genotyping call rate for the 100 samples analyzed was 96%. Using the generalized linear model (GLM) with adjustment for potential confounders and multiple comparisons, we identified 37 SNPs associated with disease, assuming a recessive mode of transmission; similarly, 48 SNPs were identified assuming a dominant mode and 53 SNPs in a continuous mode. When the 37 SNPs identified from the GLM recessive mode were used in a principal components analysis, the first principal component correctly predicted 46 of 50 cases and 47 of 50 controls. Among all the SNPs selected from GLMs for the three modes of transmission, 39 could be mapped to 1 of 33 genes. Many of these genes are involved in various cancers, including GASC1, shown previously to be amplified in ESCCs, and EPHB1 and PIK3C3. In conclusion, we have shown the feasibility of the Affymetrix 10K SNP array in genome-wide association studies of common cancers and identified new candidate loci to study in ESCC.

Carcinoma, Squamous Cell↗

PubMed2005

Allelotyping of esophageal squamous-cell carcinoma on chromosome 13 defines deletions related to family history.

We previously reported that esophageal squamous-cell cancers (ESCC) from Shanxi Province in China show frequent allelic loss on chromosome 13. Moreover, tumors from patients with a positive family history of upper gastrointestinal tumors exhibit more frequent loss of heterozygosity (LOH) on this chromosome than do those from patients without a family history. These results suggest the possibility of a familial ESCC susceptibility gene. To investigate this phenomenon further, we performed an in-depth analysis of allelic-loss data sets from both patients with and without a family history of upper gastrointestinal tumors. Comparisons between deletion frequency and location were made with respect to family history status, risk factors, and clinical/pathologic characteristics of the tumors. The analysis confirmed that tumor LOH was significantly higher in patients with a positive family history than in those who were family-history-negative, and four common deletion regions in these family-history-positive patients were defined. Statistically significant associations were also observed between allelic loss and tumor grade and location, as well as the presence of lymph node metastases. Taken together, these data indicate that a gene or genes on chromosome 13 play an important role in the etiology and progression of ESCC.

Carcinoma, Squamous Cell↗

PubMed2005

beta-Catenin splice variants and downstream targets as markers for neoplastic progression of esophageal cancer.

This study characterizes the frequency of exon 3 CTNNB1 mutations and compares the expression of CTNNB1 transcript variants and downstream targets MYC and WAF1 (p21) across the neoplastic progression of esophageal squamous cell carcinomas (ESCCs). Mutational analysis was performed on 56 tumors and corresponding germline DNA, using primers to exon 3 of CTNNB1 and SSCP DNA sequencing gels. Quantitative Real Time RT-PCR was performed on 45 foci representing the histological spectrum from normal to invasive cancer, using specific primer sets for alternative splice variants that differ by the presence (16A) or absence (16B) of a 159-bp noncoding segment of exon 16 of CTNNB1, in conjunction with downstream targets MYC and WAF1. Two unique mutations were identified, S37F in the SxxxS repeat region, and a germline polymorphism, T59A. Thus, mutation of CTNNB1 exon 3 is a rare event in this population. RT-PCR analysis successfully confirmed the presence of both beta-catenin splice variants in histologically normal and preneoplastic squamous epithelium, and invasive tumors of the esophagus, and identified a significant reduction in the 16A/16B ratio (P = 0.014) and an accompanying significant increase in the MYC/WAF1 expression ratio (P = 0.001) with progression from normal mucosa to dysplasia. This represents the first identification of two CTNNB1 transcripts in histologically "normal" esophageal squamous cells, squamous dysplasia, and invasive ESCC. These results show an increase in the minor mRNA (16B) isoform and changes in the expression of downstream markers consistent with increased transcription during the histological progression from normal to squamous dysplasia.

Alternative Splicing↗

PubMed2004

Melanoma-restricted genes.

Human metastatic cutaneous melanoma has gained a well deserved reputation for its immune responsiveness. The reason(s) remain(s) unknown. We attempted previously to characterize several variables that may affect the relationship between tumor and host immune cells but, taken one at the time, none yielded a convincing explanation. With explorative purposes, high-throughput technology was applied here to portray transcriptional characteristics unique to metastatic cutaneous melanoma that may or may not be relevant to its immunogenic potential. Several functional signatures could be identified descriptive of immune or other biological functions. In addition, the transcriptional profile of metastatic melanoma was compared with that of primary renal cell cancers (RCC) identifying several genes co-coordinately expressed by the two tumor types. Since RCC is another immune responsive tumor, commonalities between RCC and melanoma may help untangle the enigma of their potential immune responsiveness. This purely descriptive study provides, therefore, a map for the investigation of metastatic melanoma in future clinical trials and at the same time may invite consideration of novel therapeutic targets.

Journal Article↗

PubMed2004

Comprehensive characterization of annexin I alterations in esophageal squamous cell carcinoma.

PURPOSE: The purpose is to characterize alterations of the annexin I gene, its mRNA, and protein expression in esophageal squamous cell carcinoma. EXPERIMENTAL DESIGN: Fifty-six cases of esophageal squamous cell carcinoma were analyzed using four microsatellite markers flanking the annexin I gene (9q11-q21) to identify loss of heterozygosity. In addition, we performed (a) single-strand conformation polymorphism and DNA sequencing along the entire promoter sequence and coding region to identify mutations, (b) real-time quantitative reverse transcription-PCR of RNA from frozen esophageal squamous cell carcinoma tissue (n = 37) and in situ hybridization (n = 5) on selected cases to assess mRNA expression, and (c) immunohistochemistry (n = 44) to evaluate protein expression. The prevalence of the allelic variants identified in the first 56 patients was refined in 80 additional esophageal squamous cell carcinoma patients and 232 healthy individuals. RESULTS: Forty-six of 56 (82%) esophageal squamous cell carcinoma patients showed loss of an allele at one or more of the four microsatellite markers; however, only one (silent) mutation was seen. Two intragenic variants were identified with high frequency of allelic loss (A58G, 64%; L109L, 69%). Thirty of 37 (81%) esophageal squamous cell carcinoma patients showed reduced annexin I mRNA expression, which was confirmed by in situ hybridization, whereas annexin I protein expression was reduced in 79% of poorly differentiated tumor cell foci but in only 5% of well-differentiated tumor foci, although allelic loss on chromosome 9 was found in both tumor grades. CONCLUSIONS: Allelic loss of annexin I occurs frequently, whereas somatic mutations are rare, suggesting that annexin I is not inactivated in esophageal squamous cell carcinoma via a two-hit mechanism. A decrease in annexin I protein expression was confirmed, consistent with a quantitative decrease in mRNA expression, and appeared to be related to tumor cell differentiation. We conclude that annexin I is not the tumor suppressor gene corresponding to the high levels of loss of heterozygosity observed on chromosome 9 in esophageal squamous cell carcinoma; however, dysregulation of mRNA and protein levels is associated with this tumor type.

Alleles↗

PubMed2004

Selection and validation of endogenous reference genes using a high throughput approach.

BACKGROUND: Endogenous reference genes are commonly used to normalize expression levels of other genes with the assumption that the expression of the former is constant in different tissues and in different physiopathological conditions. Whether this assumption is correct it is, however, still matter of debate. In this study, we searched for stably expressed genes in 384 cDNA array hybridization experiments encompassing different tissues and cell lines. RESULTS: Several genes were identified whose expression was highly stable across all samples studied. The usefulness of 8 genes among them was tested by normalizing the relative gene expression against test genes whose expression pattern was known. The range of accuracy of individual endogenous reference genes was wide whereas consistent information could be obtained when information pooled from different endogenous reference genes was used. CONCLUSIONS: This study suggests that even when the most stably expressed genes in array experiments are used as endogenous reference, significant variation in test gene expression estimates may occur and the best normalization is achieved when data from several endogenous reference genes are pooled together to minimize minimal but significant variation among samples. We are presently optimizing strategies for the preparation of endogenous reference gene mixtures that could yield information comparable to that of data pooled from individual endogenous reference gene normalizations.

Carcinoma↗

PubMed2004

Control region mutations and the 'common deletion' are frequent in the mitochondrial DNA of patients with esophageal squamous cell carcinoma.

BACKGROUND: North central China has some of the highest rates of esophageal squamous cell carcinoma in the world with cumulative mortality surpassing 20%. Mitochondrial DNA (mtDNA) accumulates more mutations than nuclear DNA and because of its high abundance has been proposed as a early detection device for subjects with cancer at various sites. We wished to examine the prevalence of mtDNA mutation and polymorphism in subjects from this high risk area of China. METHODS: We used DNA samples isolated from tumors, adjacent normal esophageal tissue, and blood from 21 esophageal squamous cell carcinoma cases and DNA isolated from blood from 23 healthy persons. We completely sequenced the control region (D-Loop) from each of these samples and used a PCR assay to assess the presence of the 4977 bp common deletion. RESULTS: Direct DNA sequencing revealed that 7/21 (33%, 95% CI = 17-55%) tumor samples had mutations in the control region, with clustering evident in the hyper-variable segment 1 (HSV1) and the homopolymeric stretch surrounding position 309. The number of mutations per subject ranged from 1 to 16 and there were a number of instances of heteroplasmy. We detected the 4977 bp 'common deletion' in 92% of the tumor and adjacent normal esophageal tissue samples examined, whereas no evidence of the common deletion was found in corresponding peripheral blood samples. CONCLUSIONS: Control region mutations were insufficiently common to warrant attempts to develop mtDNA mutation screening as a clinical test for ESCC. The common deletion was highly prevalent in the esophageal tissue of cancer cases but absent from peripheral blood. The potential utility of the common deletion in an early detection system will be pursued in further studies.

Carcinoma, Squamous Cell↗

PubMed2004

Evaluation of BRCA2 in the genetic susceptibility of familial esophageal cancer.

Previous studies of esophageal squamous cell carcinoma (ESCC) have shown a high frequency of allelic loss on chromosome 13q, infrequent somatic mutations in BRCA2, and a suggested association between a positive family history (FH+) of upper gastrointestinal cancer and germline BRCA2 mutations. In all, 70 ESCC patients (44 FH+ and 26 FH-) were examined by direct full sequencing of germline DNA for BRCA2 mutations. In addition, 28 family members of three of these patients and 232 unrelated healthy blood bank donor controls were examined for the mutations identified in the 70 ESCC patients. Five BRCA2 germline mutations, including three not previously reported (N1600del, A2054P, and V2109I), were identified in six of 44 FH+ patients, but none of 26 FH- patients (14 vs 0%, P=0.078), consistent with our previous findings (3/34 or 9% FH+ vs 0/22 or 0% FH-, P=0.27). The cumulative frequency of BRCA2 germline mutations in ESCC patients in this and our previous study combined is 12%, with all mutations found in FH+ as opposed to FH- cases (9/78 or 12% FH+ vs 0/48 or 0% FH-, P=0.013). We conclude that germline mutations in BRCA2 in ESCC patients from this high-risk area of China are more frequent in FH+ than FH- cases, suggesting that BRCA2 may play a role in genetic susceptibility to familial ESCC.

Adult↗