Biomarkers of apoptosis and survival in esophageal squamous cell carcinoma.

BACKGROUND: Cancer of the esophagus is a deadly malignancy, and development of biomarkers that predict survival is an urgent need. The apoptotic pathways have been hypothesized as important in progression of esophageal squamous cell carcinoma (ESCC). We investigated a panel of proteins that regulate apoptosis as candidate of biomarkers of prognosis in ESCC. METHODS: Tissue microarray (TMA) including 313 surgically-resected cases of ESCC specimens was built for immunohistochemical interrogation. We evaluated seven genes in the FasL-Fas apoptotic pathway - FasL, Fas, FAS-associated death domain protein (FADD), phosphorylated-FADD, and caspase 8 and 10, and the antiapoptotic protein bcl-2. We studied pathway integrity and relations to risk and clinical factors, and determined the prognostic significance of each marker. RESULTS: Five markers showed strong inter-marker correlations (r > or = 0.28, p < 0.001), including FasL, Fas, FADD, and caspases 8 and 10. FasL and FADD also showed modest correlations with one or more cancer risk factors, but none of the markers was significantly associated with either tumor stage or lymph node metastasis, the only two clinical factors that predicted survival in these ESCC cases. Multivariate-adjusted proportional hazard regression models showed no association between protein expression and risk of death for any of the seven markers examined. CONCLUSION: Individual biomarkers in the apoptosis pathway do not appear to predict survival of patients with ESCC.

[Testosterone induces different-featured prostate hyperplasia in castrated and uncastrated mice].

OBJECTIVE: To study the different features of hyperplasia in castrated and uncastrated mice after testosterone (T) treatment. METHODS: Forty-eight BALB/c mice were randomly divided into 6 groups of 8 in each: castrated (A), uncastrated (B) , castrated + low T (C), uncastrated + low T (D), castrated + high T (E), uncastrated + high T (F). Groups C and D were treated with testosterone solution at the dose of 12.5 mg/(kg d) and Groups E and F at 125 mg/(kg d) for 20 consecutive days, while Groups A and B received saline only. All the mice were sacrificed on the 21st day, their ventral and dorsal prostate glands weighed and their pathological features studied. RESULTS: Atrophic prostates were observed in Group A, but normal in Group B; prostatic hyperplasia was found in both Group C and D, but more obvious in the latter (P <0.05); and a slightly higher degree of hyperplasia was noted in Groups E and F than in C and D. There was an increase in serum T and vascular endothelial growth factor (VEGF) concentration and a decrease in serum estrogen (E2) concentration in the testosterone treated groups. CONCLUSION: Both castrated and uncastrated mice develop prostate hyperplasia after short-term testosterone treatment, although in different degrees and with different features, which may help further the studies on the association of castration and androgen with prostate diseases.

Overexpression of CDC25B and LAMC2 mRNA and protein in esophageal squamous cell carcinomas and premalignant lesions in subjects from a high-risk population in China.

Molecular events associated with the initiation and progression of esophageal squamous cell carcinoma (ESCC) remain poorly understood but likely hold the key to effective early detection approaches for this almost invariably fatal cancer. CDC25B and LAMC2 are two promising early detection candidates emerging from new molecular studies of ESCC. To further elucidate the role of these two genes in esophageal carcinogenesis, we did a series of studies to (a) confirm RNA overexpression, (b) establish the prevalence of protein overexpression, (c) relate protein overexpression to survival, and (d) explore their potential as early detection biomarkers. Results of these studies indicated that CDC25B mRNA was overexpressed (>/=2-fold overexpression in tumor compared with normal) in 64% of the 73 ESCC cases evaluated, whereas LAMC2 mRNA was overexpressed in 89% of cases. CDC25B protein expression was categorized as positive in 59% (144 of 243) of ESCC cases on a tumor tissue microarray, and nonnegative LAMC2 patterns of protein expression were observed in 82% (225 of 275) of cases. Multivariate-adjusted proportional hazard regression models showed no association between CDC25B protein expression score and risk of death [hazard ratio (HR) for each unit increase in expression score, 1.00; P = 0.90]; however, several of the LAMC2 protein expression patterns strongly predicted survival. Using the cytoplasmic pattern as the reference (the pattern with the lowest mortality), cases with a diffuse pattern had a 254% increased risk of death (HR, 3.52; P = 0.007), cases with no LAMC2 expression had a 169% increased risk of death (HR, 2.69; P = 0.009), and cases with a peripheral pattern had a 130% greater risk of death (HR, 2.30; P = 0.02). CDC25B protein expression scores in subjects with esophageal biopsies diagnosed as normal (n = 35), dysplastic (n = 23), or ESCC (n = 32) increased significantly with morphologic progression. For LAMC2, all normal and dysplastic patients had a continuous pattern of protein expression, whereas all ESCCs showed alternative, noncontinuous patterns. This series of studies showed that both CDC25B and LAMC2 overexpress RNA and protein in a significant majority of ESCC cases. The strong relation of LAMC2 pattern of protein expression to survival suggests a role in prognosis, whereas the association of CDC25B with morphologic progression indicates a potential role as an early detection marker.

[Expression of GLUT-1, p63 and DNA-Pkcs in serous ovarian tumors and their significance].

OBJECTIVE: To investigate the expression of GLUT1, p63 and DNA-Pkcs in serous ovarian tumors and their significance. METHODS: GTUL1, p63 and DNA-Pkcs expression at protein level was detected by immunohistochemistry in patients with serous ovarian tumors. Chi-square analysis was used to assess if their expression is associated with clinicopathologic characteristics of the tumors. RESULTS: Cells in the normal ovarian tissues were not stained with GTUL1 and p63 antiserum, but DNA-Pkcs was positively stained. The intensity of GTUT1 and p63 expression was stronger in malignant ovarian serous tumors compared with other subtypes (P < 0.01). There were significant differences of DNA-PKcs among normal ovaries (100.0%), benign (95.0%), borderline (90.0%) and malignant (60.0%) serious ovarian neoplasms (P < 0.01). The level of GLUT-1 expression was correlated with FIGO staging, intraperitoneal implantation, ascites and lymph node metastasis (P < 0.05). p63 expression was associated with clinicopathologic characteristics except ascites (P < 0.05). DNA-PKcs was only correlated with FIGO staging and lymph node metastasis (P < 0.05). CONCLUSION: The results suggest that the abnormal expression of GTUT1, p63 and DNA-Pkcs may perhaps participate in serous ovarian tumor occurrence and development and may be considered as a marker reflecting tumor malignant behavior.

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.

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.

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.

Gene expression analysis of esophageal squamous cell carcinoma reveals consistent molecular profiles related to a family history of upper gastrointestinal cancer.

Tumor and matched normal tissue from 19 esophageal squamous cell carcinoma patients from a high-risk area of China were analyzed with 7680 gene cDNA microarrays. Forty-one genes were differentially expressed (P < 0.001; >/==" BORDER="0">2-fold change) between tumor and matched normal samples (13 overexpressed and 28 underexpressed). Hierarchical clustering showed consistent molecular profiles across patients. Multidimensional scaling plots visually distinguished cases by family history status, which was confirmed statistically using a global permutation test (P = 0.007); we then identified 152 genes of which the expression differed in tumors from family history positive versus negative cases (55 overexpressed and 97 underexpressed at P < 0.001). These data indicate that molecular profiles in esophageal squamous cell carcinoma are highly consistent and that expression patterns in familial cases differ from those in sporadic cases.

Infrequent mutation in the BRCA2 gene in esophageal squamous cell carcinoma.

PURPOSE: Previous studies have shown a high rate of allelic loss in esophageal squamous cell carcinoma (ESCC) in the vicinity of the BRCA2 gene. We aimed to assess whether the tumor suppressor gene BRCA2 was the inactivation target for allelic loss observed on chromosome 13q in ESCC. EXPERIMENTAL DESIGN: We examined the entire coding sequence of the BRCA2 gene for mutations using single-strand conformation polymorphism analysis and DNA sequencing in 56 ESCC patients from Shanxi, China. RESULTS: Eight mutations were identified in 5 patients (9%), including 3 with germ-line mutations and 2 with only somatic mutations. However, all but 1 of the mutations were missense or silent changes and of unknown significance. Evidence for potential biallelic inactivation was seen in only 4 (7%) cases. CONCLUSIONS: BRCA2 mutations occur in ESCC but are infrequent and of unknown consequence. The putative target tumor suppressor gene corresponding to the high rate of chromosome 13q allelic loss remains unknown.

Microsatellite alterations in esophageal dysplasia and squamous cell carcinoma from laser capture microdissected endoscopic biopsies.

Esophageal squamous cell carcinoma (ESCC), with a 5 year survival below 15%, is one of the most common fatal cancers worldwide. Significant reduction in mortality may be achieved by detecting and treating asymptomatic precursor lesions and curable early cancers. To explore this possibility and look for potential early detection markers, we examined alterations in 16 microsatellite markers in laser capture microdissected (LCM) endoscopic biopsies from the esophagus, including 15 dysplasias and 22 ESCCs, in patients from Shanxi Province, a region in north-central China. We found a significant increase in the total frequency of allelic loss with increasing disease severity. Allelic loss was seen in 2% of the markers in patients with low grade dysplasia (LGD), 15% of the markers in patients with high grade dysplasia (HGD), and 35% of the markers in patients with ESCC. Ten different markers (D3S4513, D5S2501, D8S1106, D9S118, D9S910, D13S1493, D13S894, D13S796, D15S655, and D17S1303) showed allelic loss in one or more of the premalignant lesions tested. The frequency of microsatellite instability (MSI) also increased with histological severity, from 22% in LGD to 33% in HGD and 59% in ESCC. These results indicate that the development of ESCC is associated with genetic instability, that this instability can be detected in endoscopic biopsies of recognized precursor lesions in patients without invasive cancer, and that these markers may be useful as predictive markers in the early detection of ESCC. Finally, we also report methodologic/technical modifications that enhance the use of LCM for screening endoscopic biopsies.

Detection of human papillomavirus in Chinese esophageal squamous cell carcinoma and its adjacent normal epithelium.

AIM: To investigate the putative role of human papillomavirus (HPV) infection in the carcinogenesis of esophageal squamous cell carcinoma in China. METHODS: Twenty-three esophageal squamous cell carcinoma samples and the distal normal epithelium from Shanxi Province, and 25 more esophageal squamous cell carcinoma samples from Anyang city, two areas with a high incidence of esophageal cancer in China, were detected for the existence of HPV-16 DNA by PCR, mRNA in situ hybridization (ISH) and immunohistochemistry (IHC) targeting HPV-16 E6 gene. RESULTS: There were approximately 64 % (31/48) patients having HPV-16 DNA in tumor samples, among them nearly two-thirds (19/31) samples were detected with mRNA expression of HPV-16 E6. However, in the normal esophageal epithelium from cancer patients, the DNA and mRNA of HPV-16 were found with much less rate: 34.7 % (8/23) and 26.1 % (6/23) respectively. In addition, at protein level detected by IHC assay, 27.1 % (13/48) tumor samples had virus oncoprotein E6 expression, while only one case of normal epithelium was found positive. CONCLUSION: HPV infection, especially type 16, should be considered as a risk factor for esophageal malignancies in China.

[Loss of heterozygosity in esophageal squamous cell carcinoma and its precursor lesion].

OBJECTIVE: To detect the loss of heterozygosity (LOH) in esophageal squamous cell carcinoma and adjacent high-grade squamous dysplasia, and to evaluate possible tumor suppressor genes in the development and progression of invasive malignancy. METHODS: LOH was detected in normal esophageal mucosa, high grade squamous dysplasia and esophageal squamous cell carcinoma using microdissection and polymerase chain reaction technology. The changes of LOH at seven microsatellite markers and the relationship between LOH rate and clinicopathologic parameters were analyzed. RESULTS: In high grade squamous dysplasia, LOH was detected at D13S802 (40%), D13S267 (32%), D13S221 (31%), D9S942 (30%), D17S520 (24%) and D9S171 (33%). However, D17S1798 LOH was not detected. In invasive squamous cell carcinoma, LOH was detected as follows: D13S267 (71%), D13S802 (58%), D17S520 (55%), D13S221 (45%), D9S942 (43%), D9S171 (33%) and D17S1798 (11%). The frequency of LOH in the seven microsatellite markers, the pathologic grade, clinical stage and occurrence of lymph node metastasis did not show any statistically significant correlation (P > 0.05). CONCLUSIONS: The progression from normal squamous epithelium to high grade squamous dysplasia and subsequently to invasive squamous cell carcinoma of the esophagus was associated with accumulation of genetic errors. Possible tumor suppressor genes related to the development of esophageal squamous cell carcinoma may exist near D13S802 (13q12.12). Possible tumor suppressor genes near D13S267 (13q13.1), D17S1798 (17p13.3) and D17S520 (17p13.1) may be related to the progression of esophageal squamous cell carcinoma.

Fascin and CK4 as biomarkers for esophageal squamous cell carcinoma.

BACKGROUND: Several studies have suggested that fascin, cytokeratin 14 and cytokeratin 4 may have significant roles as biomarkers for the progression and survival of esophageal squamous cell carcinoma (ESCC). MATERIALS AND METHODS: This study performed immunohistochemistry in tissue microarrays, profiling premalignant lesions and invasive tumors. RESULTS: Fascin increased across the following states as follows: normal-appearing epithelium (26%) to dysplasia (46%) to ESCC (68%), while CK4 was undetectable in ESCC (0%) compared to normal-appearing epithelium (45%) or dysplasia (41%). CK14 was elevated and invariant in expression. In regression analyses, compared to normal-appearing epithelium, higher fascin expression was associated with a 36% increased risk of dysplasia (odds ratio=1.36) and a 56% increased risk of invasive ESCC (odds ratio=1.56). CONCLUSION: Expression of fascin is up-regulated in the transformation from normal-appearing epithelium, through dysplasia, into invasive carcinoma. Expression of CK4, CK14 and fascin did not correlate with patient survival. Fascin has a potential role as an early detection biomarker and CK4 as a tumor marker in ESCC.

Global gene expression profiling and validation in esophageal squamous cell carcinoma and its association with clinical phenotypes.

PURPOSE: Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor with poor prognosis. Understanding molecular changes in ESCC will enable identification of molecular subtypes and provide potential targets for early detection and therapy. EXPERIMENTAL DESIGN: We followed up a previous array study with additional discovery and confirmatory studies in new ESCC cases by using alternative methods. We profiled global gene expression for discovery and confirmation, and validated selected dysregulated genes with additional RNA and protein studies. RESULTS: A total of 159 genes showed differences with extreme statistical significance (P < E-15) and 2-fold differences or more in magnitude (tumor/normal RNA expression ratio, N = 53 cases), including 116 upregulated and 43 downregulated genes. Of 41 genes dysregulated in our prior array study, all but one showed the same fold change directional pattern in new array studies, including 29 with 2-fold changes or more. Alternative RNA expression methods validated array results: more than two thirds of 51 new cases examined by real-time PCR (RT-PCR) showed 2-fold differences or more for all seven genes assessed. Immunohistochemical protein expression results in 275 cases which were concordant with RNA for five of six genes. CONCLUSION: We identified an expanded panel of genes dysregulated in ESCC and confirmed previously identified differentially expressed genes. Microarray-based gene expression results were confirmed by RT-PCR and protein expression studies. These dysregulated genes will facilitate molecular categorization of tumor subtypes and identification of their risk factors, and serve as potential targets for early detection, outcome prediction, and therapy.

[A comparative study on the risks of esophagus-cancer patients among factors as blood relatives, paternal line, matriarchal and different sex].

OBJECTIVE: In order to provide new clues on the cause of esophagus-cancer through seeking for information among the relatives of esophagus-cancer-patients at high-risk, contrast analysis was carried out to compare the ORs between esophagus-cancer cases and the relatives of the patients. METHODS: Case-control study was adopted on 720 cases and 720 controls who were kin relatives of the patients. RESULTS: (1) Risk of the relatives to the esophagus-cancer-patient group (1.34% - 2.24%) was obviously higher than the control group (0.78% - 1.21%) (P < 0.01). In 1(st) grade relatives, the risk of parent's to the esophagus-cancer patients (6.11%) was obviously higher than the control group (2.97%) (P < 0.01). (2) According to the cascade analysis to the cases of both paternal and matriarchal, lines, results showed that the risks of both the paternal line (0.87% - 1.01%) and the matriarchal line (0.50% - 0.79%) in the group of esophagus-cancer cases were all obviously higher than the lines in the control groups (0.53% - 0.65%) and (0.38% - 0.47%). Data also showed that the risk among the male relatives of paternal line (eg: grandfathers', father's, uncles' etc.) in the group of cases was 2.68% while the matriarchal (eg: grandmother's, mother's, aunts' etc.) was 1.91%. Both figures were obviously higher than that in the control group (1.50% and 0.92%, P < 0.01). CONCLUSION: The risk factor of esophagus cancer of the next generation seemed higher if the father and his brothers or mother and her sisters having had esophagus-cancers.

[Studies on hereditary epidemiology of cardia cancer in Shanxi province.].

OBJECTIVE: Studies on cardia-cancer caused by hereditary factors. METHODS: Case-control method was adopted, with information including name, sex, date of birth, date of death of all the I, II, III relatives of the patients, diagnosis and the treatment collected. The hereditary probability of cardia cancer and the separation degree were calculated by Falconer and Li-Mentel-Gart. RESULTS: (1) Prevalence rates of cardia-cancer on relative I, relative II, relative III of cardia-cancer patients appeared to be 0.54%, 0.04%, and 0.05% respectively. Prevalence rates of upper-digestive-tract-cancer of relative I, relative II, relative III of cardia-cancer patients showed as: 2.50%, 0.36% and 0.13% respectively. Data showed that relative I > relative II > relative III and family cluster existed in both males and females. (2) Cardia-cancer hereditary probability of the relative I cardia-cancer probands was 11.71%, with males as 14.01% and females as 14.72%. The upper-digestive-tract-cancer hereditary probability of the relative I cardia-cancer probands was 13.87%, with males as 11.49% and females as 23.08%, both below 25%, indicating this was a low hereditary cancer. (3) The upper-digestive-tract-cancer separation of the blood compatriots of cardia-cancer patients was 0.0452, with males as 0.0441 and females as 0.0507, both below 0.25, indicating the nature of a multi-gene but not single-gene hereditary way. CONCLUSION: Hereditary factor is recognized as one of the high risk cardia cancer, but not the most risky factor causing the high morbidity of cardia cancer in Shanxi province.

Genomic characterization of esophageal squamous cell carcinoma from a high-risk population in China.

Genomic instability plays an important role in most human cancers. To characterize genomic instability in esophageal squamous cell carcinoma (ESCC), we examined loss of heterozygosity (LOH), copy number (CN) loss, CN gain, and gene expression using the Affymetrix GeneChip Human Mapping 500K (n = 30 cases) and Human U133A (n = 17 cases) arrays in ESCC cases from a high-risk region of China. We found that genomic instability measures varied widely among cases and separated them into two groups: a high-frequency instability group (two-thirds of all cases with one or more instability category of > or =10%) and a low-frequency instability group (one-third of cases with instability of <10%). Genomic instability also varied widely across chromosomal arms, with the highest frequency of LOH on 9p (33% of informative single nucleotide polymorphisms), CN loss on 3p (33%), and CN gain on 3q (48%). Twenty-two LOH regions were identified: four on 9p, seven on 9q, four on 13q, two on 17p, and five on 17q. Three CN loss regions-3p12.3, 4p15.1, and 9p21.3-were detected. Twelve CN gain regions were found, including six on 3q, one on 7q, four on 8q, and one on 11q. One of the most gene-rich of these CN gain regions was 11q13.1-13.4, where 26 genes also had RNA expression data available. CN gain was significantly correlated with increased RNA expression in over 80% of these genes. Our findings show the potential utility of combining CN analysis and gene expression data to identify genes involved in esophageal carcinogenesis.