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Background: Long‐term anti‐EGFR antibody treatment increases the risk of severe dermatologic toxicities. This single‐arm, phase II trial aimed to investigate the strategy of switching from cetuximab to bevacizumab in combination with FOLFIRI based on early tumor shrinkage (ETS) in patients with RAS wild‐type metastatic colorectal cancer (mCRC). Methods: Radiologic assessment was performed to evaluate ETS, defined as ≥20% reduction in the sum of the largest diameters of target lesions 8 weeks after the introduction of FOLFIRI plus cetuximab. ETS‐negative patients switched to FOLFIRI plus bevacizumab, whereas ETS‐positive patients continued FOLFIRI plus cetuximab for eight more weeks, with a switch to FOLFIRI plus bevacizumab thereafter. The primary endpoint was progression‐free survival. Results: This trial was prematurely terminated due to poor accrual after a total enrollment of 30 patients. In 29 eligible patients, 7 were ETS‐negative and 22 were ETS‐positive. Two ETS‐negative patients and 17 ETS‐positive patients switched to FOLFIRI plus bevacizumab 8 weeks and 16 weeks after initial FOLFIRI plus cetuximab, respectively. Median progression‐free and overall survival durations were 13.4 and 34.7 months, respectively. Six (20%) patients experienced grade ≥3 paronychia, which improved to grade ≤2 by 18 weeks. Grade ≥3 acneiform rash, dry skin, and pruritus were not observed in any patients. Conclusions: Our novel treatment strategy delivered acceptable survival outcomes and reduced severe dermatologic toxicities. [ABSTRACT FROM AUTHOR]

Non-small-cell lung cancer patients with locally advanced or metastatic disease at the time of diagnosis show marginal response to chemotherapy in terms of tumor shrinkage, time to progression and median survival. The identification and implementation of predictive genetic markers of response-specific cytotoxic drugs is a priority of current research and future trials. In this study, we have used quantitative PCR to analyse expression of ?-tubulin III, stathmin, RRM1, COX-2 and GSTP1 in mRNA isolated from paraffin-embedded tumor biopsies of 75 nonsmall-cell lung cancer patients treated as part of a large randomized trial. In total, 22 patients were treated with gemcitabine/cisplatin, 25 with vinorelbine/cisplatin and 28 with paclitaxel/carboplatin. There were no differences in clinical characteristics and transcript levels in the pretreatment biopsies according to treatment arm. Patients with low ?-tubulin III levels had better response in the paclitaxel/carboplatin arm (P=0.05), and those with low RRM1 levels showed a tendency to better response in the gemcitabine/cisplatin arm. Time to progression was influenced by ?-tubulin III (P=0.03) and stathmin (P=0.05) levels in the vinorelbine/cisplatin arm, and there was a tendency toward correlation between ?-tubulin III levels and time to progression in the paclitaxel/carboplatin arm. RRM1 levels influenced time to progression (P=0.05) and even more so, survival (P=0.0028) in the gemcitabine/cisplatin arm. The predictive value of ?-tubulin III, stathmin and RRM1 should be tested in prospective customized chemotherapy trials, the results of which will help tailor chemotherapy to improve patient survival.Oncogene (2003) 22, 3548-3553. doi:10.1038/sj.onc.1206419 [ABSTRACT FROM AUTHOR]

Methylation of 5′ CpG islands in promoter and upstream coding regions has been identified as a mechanism for transcriptional inactivation of tumor suppressor genes. The purpose of this study was to determine whether hypermethylation of the adenomatous polyposis coli (APC) gene promoter occurs in primary non-small cell lung cancer (NSCLC), and whether hypermethylated APC has any relationship with survival. APC promoter 1A methylation was determined in normal and corresponding tumor tissue from 91 NSCLC patients and in a control group of 10 patients without cancer, using a quantitative fluorogenic real-time PCR (Taqman®) system. APC promoter methylation was detectable in 86 (95%) of 91 tumor samples, but also in 80 (88%) of 91 normal samples of NSCLC patients, and in only two (20%) of 10 normal lung tissues of the control group. The median level of APC promoter methylation was 4.75 in tumor compared to 1.57 in normal lung tissue (P<0.001). Patients with low methylation status showed significantly longer survival than did patients with high methylation status (P=0.041). In a multivariate analysis of prognostic factors, APC methylation was a significant independent prognostic factor (P=0.044), as were pT (P=0.050) and pN (P<0.001) classifications. This investigation shows that APC gene promoter methylation occurs in the majority of primary NSCLCs. High APC promoter methylation is significantly associated with inferior survival, showing promise as a biomarker of biologically aggressive disease in NSCLC. Oncogene (2001) 20, 3528–3532. [ABSTRACT FROM AUTHOR]

Abstract: Background: The effect of the apoptosis related gene Bcl-2 in the pathogenesis in NSCLC remains poorly investigated. Hence the aim of this study was to explore the potential role of Bcl-2 mRNA expression as a prognostic biomarker in patients with curatively resected NSCLC. Methods: 91 tumor and matching normal tissue samples from patients with NSCLC were analyzed using a quantitative real-time RT-PCR method. The relative Bcl-2 mRNA expression was measured using β-actin as a reference gene. 45 of the 91 patients had stage I tumors (49%), 19 had stage II (21%) and 27 had stage IIIa (30%). Squamous cell carcinoma was found in 43 patients (47%), adenocarcinoma in 33 (36%) and in large cell carcinoma in 15 (17%) of the patients. Results: Bcl-2 mRNA expression was detected in 83 (91%) of the investigated tumor samples and in 74 (81%) of the normal lung tissue. The median gene expression was 0.147 in tumor tissue and 0.144 in matching normal lung tissue (p =n.s., Wilcoxon Test). No associations were seen between the tumorous Bcl-2 mRNA expression levels and clinical or histopathologic parameters such as gender, tumor size, TNM stadium and grading, but with tumor histology and smoking. With a follow-up of 85.9 months, the median survival time was 59.7 months. Bcl-2 mRNA expression was significantly associated with patients prognosis (p =0.013, log-rank test). Multivariate regression analysis revealed Bcl-2 expression status and tumor stage as independent prognostic factor. Conclusions: Bcl-2 expression in NSCLC is not associated with the pathogenesis of this disease. Our data suggests that Bcl-2 mRNA expression plays a crucial role in the biological behavior of NSCLCs. Quantitation of Bcl-2 expression improves estimation of prognosis and appears to identify patients who will benefit from intensive adjuvant therapy. [ABSTRACT FROM AUTHOR]

PURPOSE: The role of adjuvant chemotherapy in patients with locally advanced bladder cancer still remains to be defined. We hypothesized that assessing the gene expression of the chemotherapy response modifiers multidrug resistance gene 1 (MDR1) and excision repair cross-complementing 1 (ERCC1) may help identify the group of patients benefiting from cisplatin-based adjuvant chemotherapy. EXPERIMENTAL DESIGN: Formalin-fixed paraffin-embedded tumor samples from 108 patients with locally advanced bladder cancer, who had been enrolled in AUO-AB 05/95, a phase 3 trial randomizing a maximum of three courses of adjuvant cisplatin and methotrexate (CM) versus methotrexate, vinblastine, epirubicin, and cisplatin (M-VEC), were included in the study. Tumor cells were retrieved by laser-captured microdissection and analyzed for MDR1 and ERCC1 expression using a quantitative real-time reverse transcription-polymerase chain reaction assay. Gene expression levels were correlated with clinical outcomes by multivariate Cox proportional hazards regression analysis. RESULTS: Expressions of MDR1 and ERCC1 were independently associated with overall progression-free survival (P = .001, relative risk = 2.9 and P = .01, relative risk = 2.24, respectively). The correlation of high MDR1 expression with inferior outcome was stronger in patients receiving M-VEC, whereas ERCC1 analysis performed equally in the CM and M-VEC groups. CONCLUSIONS: High MDR1 and ERCC1 gene expressions are associated with inferior outcome after cisplatin-based adjuvant chemotherapy for locally advanced bladder cancer. Prospective studies are warranted to define a role for MDR1 and ERCC1 analysis in individualizing multimodality treatment in locally advanced bladder cancer. [ABSTRACT FROM AUTHOR]

High expression levels of EGFR mRNA are reported to be associated with a higher response probability in epidermal growth factor receptor (EGFR) targeted drugs. Our aim was to determine how EGFR gene expression levels in primary colorectal cancer (CRC) were related to those in liver metastases. 31 pairs of primary CRC and corresponding liver metastases were analyzed. Gene expression level was measured using real-time RT-PCR. No significant difference was observed between median mRNA expression levels of EGFR in primary cancer and those in corresponding liver metastases ( P = 0.99). When matched tissue sets were compared on an individual basis, there was a significant correlation for EGFR mRNA expression between primary cancer and corresponding liver metastases ( rs = 0.78, P < 0.0001). A good prediction of EGFR mRNA levels in liver metastases can be obtained by measuring those in the primary CRC. [ABSTRACT FROM AUTHOR]

Background: Thymidylate synthase (TS) is known to have a unique 28 bp tandemly repeated sequence in the promoter region, and the majorities of subjects have a heterozygous double repeat/triple repeat genotype in their non-cancerous tissue. Loss of heterozygosity (LOH) at the TS locus is known to occur in cancer patients, but there is no evidence that it is present in precancerous tissue. The aim of this study was to analyze the frequency and timing of LOH at the TS locus in Barrett-associated adenocarcinoma (BA) and its precursory lesions, such as intestinal metaplasia (IM) and dysplasia. Methods: One hundred twenty-three samples (including 37 with gastroesophageal reflux disease (GERD), 29 with IM, 13 with dysplasia, and 44 with BA) were obtained from 100 patients. Biopsies were obtained from the lower esophageal mucosa/IM/dysplasia/BA, when available. Normal squamous tissue from the upper esophagus was taken as a control. All tissues were analyzed for the TS genotype and TS mRNA expression using the real-time reverse-transcription polymerase chain reaction (RT-PCR) method after laser-capture microdissection. Results: Among the patients with informative heterozygous genotype in their control samples, no sample with LOH at the TS locus was observed in the lower esophageal mucosa in GERD patients (0/22 samples). However, 6 out of 21 samples (28.6%) had LOH in IM, 2 of 7 (28.6%) in dysplasia, and 10 of 25 (40.0%) in BA. No significant difference in TS mRNA expression levels was observed between TS genotypes. Conclusion: Our results demonstrate that LOH is a relatively frequent and early event in the IM-BA sequence. [ABSTRACT FROM AUTHOR]

Context.--Expression profiling by microarrays and real-time polymerase chain reaction-based assays is a powerful tool for classification and prognostication of disease; however, it remains a research tool, largely reliant on frozen tissue. Limiting the utility of expression profiling is the isolation of quality nucleic acids from formalin-fixed, paraffin-embedded tissue. The collection, handling, and processing of tissue directly impacts the biomolecules that can be recovered from it. High-quality nucleic acids can be obtained from formalin-fixed, paraffin-embedded tissue, but greater attention to all steps in the process of tissue handling and preparation is required. Objective.--To summarize the current state-of-the-art of preanalytic factors in tissue handling and processing as they impact the quality of RNA obtainable from formalin-fixed, paraffin-embedded tissue. The goals are to provide recommendations that will improve RNA quality for expression profiling from formalin-fixed, paraffin-embedded tissue and highlight areas for additional research. Tissue is an analyte and it must be handled in a standardized fashion to provide consistent results. Data Sources.--The literature was reviewed. Consultation with industry and academic leaders in the use of RNA for expression profiling was obtained to identify areas for additional research. Conclusions.--Development of RNA-based assays from formalin-fixed, paraffin-embedded tissue is feasible. Greater attention to tissue handing and processing is essential to improve the quality of biospecimens for the development of robust RNA-based assays. Standardization of procedures and vigorous testing of alternative protocols are required to ensure that these assays function as designed. [ABSTRACT FROM AUTHOR]

Background: Pancreatic cancer still has one of the worst prognoses of all cancers with a 5-year survival rate of 5%, making it necessary to find markers or gene sets that would further classify patients into different risk categories and thus allow more individually adapted multimodality treatment regimens. Especially heparanase (HPSE) has recently been discussed as a key factor in pancreatic cancer.Materials and Methods: Paraffin-embedded tissue samples were obtained from 41 patients with pancreatic adenocarcinoma who were scheduled for primary surgical resection. Direct quantitative real-time reverse transcriptase polymerase chain reaction (TaqMan) assays were performed in triplicates to determine HPSE, hypoxia inducible factor-1 alpha (HIF1a), platelet-derived growth factor alpha (PDGFA), heparin-binding EGF-like growth factor (HB-EGF), and basic fibroblast growth factor (bFGF) gene expression levels.Results: HPSE was significantly correlated to PDGFA (p = 0.04) and HIF1a (p = 0.04). The correlation of HIF1a to bFGF and HB-EGF was significant (p = 0.04, p = 0.02). Stepwise multiple linear regression models showed a significant independent association of HPSE with lymph node metastasis (p = 0.025) and with dedifferentiation (p = 0.042).Conclusions: Heparanase seems to be significantly associated with lymph node metastasis (p = 0.025) as well as dedifferentiation (p = 0.042). We assume that HPSE plays a crucial role for the aggressiveness of pancreatic cancer. Larger studies including more patients seem to be warranted. [ABSTRACT FROM AUTHOR]

PURPOSE: Pancreatic cancer still has one of the worst prognoses in gastrointestinal cancers with a 5-year survival rate of 5%, making it necessary to find markers or gene sets that would further classify patients into different risk categories and thus allow more individually adapted multimodality treatment regimens. In this study, we investigated the prognostic values of HIF1a, bFGF, VEGF, and PDGFA gene expressions as well as their interrelationships. EXPERIMENTAL DESIGN: Formalin-fixed paraffin-embedded tissue samples were obtained from 41 patients with pancreatic adenocarcinoma (age, 65; range, 34-85 years). After laser capture microdissection, direct quantitative real-time reverse transcription-polymerase chain reaction assays were performed in triplicates to determine HIF1a, PDGFA, VEGF, and bFGF gene expression levels. Multivariate Cox proportional hazards regression analysis was used to assess the impact of HIF1a gene expression on prognosis. RESULTS: HIF1a was significantly correlated to every gene we tested: bFGF (P = .04), VEGF (P = .02), and PDGFA (P = .03). Tumor size, P = .04, and high HIF1a mRNA expression (cutoff, 75th percentile) had a significant impact on survival, P = .009 (overall model fit, P = .02). High HIF1a expression had a sensitivity of 87.1% and a specificity of 55.6% for the diagnosis short (<6 months) versus long (6-60 months) survival. CONCLUSIONS: Measuring PDGFA, bFGF, and HIF1a expression may contribute to a better understanding of the prognosis of patients with pancreatic cancer and may even play a crucial role for the distribution of patients to multimodal therapeutic regimens. Larger studies including patients treated with actual chemotherapeutics seem to be warranted. [ABSTRACT FROM AUTHOR]

Reliable quantification of gene expression offers the possibility of more accurate and prognostically relevant characterization of tissues than potentially subjective interpretations of histopathologists. We measured the expression of 18 selected genes and compared them to histological features in a spectrum of esophageal disease to evaluate the feasibility of molecular characterization of normal and pathologic esophageal epithelia. Esophageal tissue biopsies from 82 patients with foregut symptoms were laser capture microdissected, and the expression levels of 18 selected genes were measured by quantitative real-time polymerase chain reaction. Linear discriminant analysis, which uses combinations of genes to distinguish between histological groups, was performed to compare gene expression and the following five histological groups: (1) normal squamous epithelium (n = 35), (2) reflux esophagitis (n = 13), (3) non-dysplastic Barrett's (n = 33), (4) dysplastic Barrett's (n = 16), (5) adenocarcinoma (n = 31). A panel of seven genes had 90-94% predictive power to distinguish non-dysplastic and dysplastic Barrett's esophagus. Clustering analysis revealed structure in gene expression values even in the absence of histology. Expression levels in 17 genes differed significantly across histological groups. Classification based on gene expression agreed with histopathological assessment in the following percentage of cases: normal squamous epithelium = 53%, reflux esophagitis = 31%, non-dysplastic Barrett's = 76%, dysplastic Barrett's = 40%, and adenocarcinoma = 59%. Interestingly, predictive power improved markedly when inflammatory and dysplastic tissues were removed (77-94%). Gene expression classification agrees well with histopathological examination. When differences occur, it is unclear whether this effect is due to intraobserver variability in pathological diagnosis or to a genuine difference between gene expression and histopathology. [ABSTRACT FROM AUTHOR]

Recurrence is a significant clinical problem for patients with rectal cancer treated with adjuvant chemoradiation. Previous studies have suggested that determining intratumoral gene expression of key genes may be helpful in predicting clinical outcome of patients with gastrointestinal malignancies undergoing chemotherapy. The role of molecular predictors for prediction of recurrence in the setting of adjuvant chemoradiotherapy is not well established. The present study was designed to identify a genetic profile that would be associated with recurrence in patients with rectal cancer treated with adjuvant chemoradiation therapy. A retrospective study with a longitudinal cohort and a cross-sectional cohort of 67 patients with locally advanced rectal cancer who underwent cancer resection, followed by 5-fluorouracil (5-FU) plus pelvic radiation was conducted. Total RNA was extracted from formalin-fixed, paraffin-embedded, laser-captured-microdissected tissue. We determined mRNA levels of genes involved in the 5-FU pathway (thymidylate synthase, dihydropyrimidine dehydrogenase), DNA-repair (excision-repair cross-complementing factor 1, Rad51), angiogenesis/radiation sensitivity [vascular endothelial growth factor (VEGF)] and radio-sensitivity [epidermal growth factor receptor (EGFR)] in tumor tissue and tumor-adjacent normal tissue by quantitative reverse transcriptase-polymerase chain reaction. In univariate analysis, only intratumoral gene expression level of VEGF (P=0.055) was associated with recurrence, whereas elevated mRNA expression levels of thymidylate synthase (P=0.008), VEGF (P=0.023) and EGFR (P=0.004) in tumor-adjacent normal tissue were significantly associated with recurrence. Multivariate analysis using recursive partitioning indicated that distinct groups of recurrence could be defined by elevated mRNA expression levels of VEGF, EGFR in tumor-adjacent normal tissue, and Rad51 in tumor tissue. These data suggest that the genetic profile of the tumor-adjacent normal tissue may be associated with treatment failure, indicating that tumor microenvironment may be more important in the development of recurrence of rectal tumors than formerly expected. [ABSTRACT FROM AUTHOR]

BACKGROUND: In some patients GERD presents with heartburn and regurgitation symptoms but a relative paucity of endoscopic and clinical findings, while in others symptoms may be minor or absent yet there is significant mucosal damage on endoscopy including the presence of Barrett's esophagus. The initial injury of gastroesophageal reflux is to the squamous esophageal mucosa, but while substantial research has been devoted to determining which genes are involved in the progression of Barrett's to dysplasia and cancer, little is known about the gene expression alterations in the squamous mucosa of patients with reflux. We hypothesized that the expression of cyclooxygenase-2 (Cox-2) might be increased in the squamous esophageal mucosal of patients with reflux, and might be a molecular indicator of reflux injury. Further, we hypothesized that Cox-2 expression in the squamous mucosa would be reduced following the elimination of reflux with an antireflux operation. METHODS: Biopsies of the distal esophageal squamous mucosa were taken 3 cm above the squamocolumnar junction (SCJ) in 28 GERD patients before and after Nissen fundoplication. Following microdissection and RNA isolation, quantitative real-time PCR was used to measure Cox-2 gene expression in paraffin-embedded (N = 16) and fresh frozen (N = 12) tissue. Biopsies from patients (paraffin N = 15, frozen N = 14) with normal acid exposure and no evidence of mucosal injury were analyzed as controls. RESULTS: Median Cox-2 expression in the squamous epithelium from paraffin embedded biopsies in patients with reflux disease was significantly increased compared to controls ( p= 0.04). The presence of esophagitis or Barrett's esophagus did not significantly alter the expression of Cox-2 compared to patients with nonerosive reflux disease (NERD). After antireflux surgery median Cox-2 expression values were significantly reduced ( p= 0.0003) and were normalized to levels similar to controls without reflux ( p= 0.74). Similar results were observed in the prospectively obtained fresh frozen tissue. CONCLUSIONS: Cox-2 gene expression is increased in the distal esophageal squamous mucosa of most patients with GERD, and the elevation was similar whether there was mucosal injury in the form of esophagitis or Barrett's or no visible mucosal injury. This suggests that increased Cox-2 expression may serve as a molecular marker of reflux disease. The increased Cox-2 expression in patients with reflux was usually normalized following antireflux surgery. These findings demonstrate for the first time that gene expression can be altered by surgical correction of reflux. Thus, in addition to symptom control and improvement in the quality of life, perhaps future studies assessing the efficacy of antireflux therapy should also focus on the impact of the therapy on gene expression in the esophageal squamous mucosa. [ABSTRACT FROM AUTHOR]

Background: To find out if neoadjuvant therapy could alter tumor response determinants that might affect tumor sensitivity to the treatment, we investigated intratumoral expressions of genes associated with chemosensitivity, radiosensitivity, or both before and after radiochemotherapy. Study design: Twenty-four patients with locally advanced, resectable esophageal cancer (cT2–4,Nx,M0) received neoadjuvant 5-FU/cisplatin/36 Gy treatment followed by transthoracic en bloc esophagectomy. Expression levels of thymidylate synthase, dihydropyrimidine dehydrogenase, excision repair cross-complementing gene 1 , glutathione S-transferase Pi, epidermal growth factor receptor, and HER2 were measured in matched preradiochemotherapy endoscopic tumor biopsies and in postradiochemotherapy resection specimens. mRNA was isolated from formalin-fixed, paraffin-embedded, laser microdissected tumor tissues, and a quantitative fluorescent dye real-time reverse transcription polymerase chain reaction system was used for gene expression measurement. Results: There was a significant reduction in the expression levels of thymidylate synthase (p &#60; 0.01), dihydropyrimidine dehydrogenase (p = 0.03), excision repair cross-complementing gene 1 (p &#60; 0.01), glutathione S-transferase Pi (p = 0.03), HER2 (p &#60; 0.01), and epidermal growth factor receptor (p = 0.04). The change in the levels of epidermal growth factor receptor mRNA in post- compared with pretreatment specimens was significantly associated with the histopathologic grade of regression (p = 0.01). Conclusions: The expression levels of a set of genes that are possible determinants of 5-FU/cisplatin/radiation therapy antitumor activity are significantly downregulated by neoadjuvant radiochemotherapy in esophageal cancer. [Copyright &y& Elsevier]

Cyclooxygenase (Cox-2) is implicated in the pathogenesis of many cancers including esophageal adenocarcinoma (EAC), whereas the role of the isoform Cox-1 in carcinogenesis is not well understood. To further elucidate the role of these factors in the development of EAC, we measured the gene expressions (mRNA levels) of Cox-2 and Cox-1 by real-time quantitative polymerase chain reaction (QRT-PCR) in tissues from normal esophagus with and without erosive gastroesophageal reflux disease (GERD), Barrett''s esophagus (BE), dysplasia, adenocarcinoma, and in healthy gastric antrum. All tissues were purified by laser capture microdissection from endoscopic or surgical resection specimens. Median Cox-2 gene expression did not differ significantly among the esophageal control groups but was elevated 5-fold in BE, 8-fold in dysplasia and 16-fold in EAC compared to normal esophageal controls with no erosive GERD. Erosive GERD tissue had slightly higher median Cox-2 expression but Cox-2 expression in normal antrum was much higher than that in a normal esophagus, close to that of dysplasia. In contrast to that of Cox-2, Cox-1 expression was significantly decreased in all neoplastic tissues compared to normal controls. Cox-1 and Cox-2 expression varied over a wide range in the neoplastic tissues but over a relatively narrow range in the esophageal normal tissues. The occurrence of substantial alterations in Cox-1 and Cox-2 expression at the BE stage indicates that these are early events in the development of EAC. These results confirm the important role of Cox-2 amplification in the pathogenesis of esophageal adenocarcinoma, but the unexpected down-regulation of Cox-1 raises questions about its role in carcinogenesis. [Copyright &y& Elsevier]

In order to identify genes or combination of genes that have the power to discriminate between premalignant Barrett's esophagus and Barrett's associated adenocarcinoma, we analysed a panel of 23 genes using quantitative real-time RT-PCR (qRT-PCR, Taqman®) and bioinformatic tools. The genes chosen were either known to be associated with Barrett's carcinogenesis or were filtered from a previous cDNA microarray study on Barrett's adenocarcinoma. A total of 98 tissues, obtained from 19 patients with Barrett's esophagus (BE group) and 20 patients with Barrett's associated esophageal adenocarcinoma (EA group), were studied. Triplicate analysis for the full 23 gene of interest panel, and analysis of an internal control gene, was performed for all samples, for a total of more than 9016 single PCR reactions. We found distinct classes of gene expression patterns in the different types of tissues. The most informative genes clustered in six different classes and had significantly different expression levels in Barrett's esophagus tissues compared to adenocarcinoma tissues. Linear discriminant analysis (LDA) distinguished four genetically different groups. The normal squamous esophagus tissues from patients with BE or EA were not distinguishable from one another, but Barrett's esophagus tissues could be distinguished from adenocarcinoma tissues. Using the most informative genes, obtained from a logistic regression analysis, we were able to completely distinguish between benign Barrett's and Barrett's adenocarcinomas. This study provides the first non-array parallel mRNA quantitation analysis of a panel of genes in the Barrett's esophagus model of multistage carcinogenesis. Our results suggest that mRNA expression quantitation of a panel of genes can discriminate between premalignant and malignant Barrett's disease. Logistic regression and LDAs can be used to further identify, from the complete panel, gene subsets with the power to make these diagnostic distinctions. Expression analysis of a limited number of highly selected genes may have clinical usefulness for the treatment of patients with this disease.Oncogene (2004) 23, 4780-4788. doi:10.1038/sj.onc.1207663 Published online 26 April 2004 [ABSTRACT FROM AUTHOR]

The Barrett''s multistage process is characterized histopathologically by progression from Barrett''s intestinal metaplasia to Barrett''s esophagus with dysplasia and ultimately adenocarcinoma. Understanding of the molecular alterations in this multistage process may contribute to improved diagnosis and treatment. Retinoid X receptors (RXR) play an important role in regulating the morphogenesis, development, growth, and differentiation of cells. Alterations in RXR expression have been observed in a variety of solid tumors; however, the role in Barrett''s esophagus disease has yet to be determined. The aim of this study was to assess the prevalence and timing of RXR messenger RNA expression in the Barrett''s metaplasia-dysplasia-adenocarcinoma sequence and to investigate its role in the development and progression of this disease. We analyzed the mRNA expression of all three RXR subtypes (RXR-alpha, RXR-beta, and RXR-gamma) by using a quantitative real-time reverse transcription–polymerase chain reaction method in 108 specimens from 19 patients with Barrett''s esophagus without carcinoma (BE group), 20 patients with Barrett''s-associated adenocarcinoma (EA group), and a control group of 10 patients without evidence of gastroesophageal reflux disease (CG). RXR-α mRNA expression was significantly decreased (P < 0.001; Kruskal-Wallis test), and RXR-γ was significantly increased (P < 0.001) at higher stages in Barrett''s esophagus. RXR-β expression was highest in Barrett''s tissues and was significantly increased compared to normal squamous tissues (P = 0.01; Wilcoxon test) and adenocarinoma tissues (P = 0.018, Mann-Whitney test). RXR-α and RXR-β mRNA expression was significantly associated in normal squamous esophagus tissues (r2 = 0.49; P < 0.001; Spearman test), Barrett''s tissues (r2 = 0.63; P < 0.001), and adenocarcinoma tissues (r2 = 0.68; P = 0.001). There were significant differences in RXR-α (P = 0.011) and RXR-β (P = 0.005) mRNA expression in histopathologically normal squamous esophagus tissues in patients with cancer and the control group without evidence of gastroesophageal reflux disease. These findings suggest that alterations in the mRNA expression of all three RXR subtypes are frequent events in the development and progression of Barrett''s esophagus and associated adenocarcinoma, that RXR mRNA expression levels may be useful biomarkers for this disease, and that a widespread “field-effect” is present in the normal esophagus of patients with esophageal adenocarcinoma. [Copyright &y& Elsevier]

The glutathione S–transferases (GSTs) are a family of enzymes that play an important role in the prevention of cancer by detoxifying numerous potentially carcinogenic compounds. GSTs conjugate reduced glutathione to a variety of electrophilic and hydrophobic compounds, converting them into more soluble, more easily excretable compounds. Decreased glutathione S–transferase-pi (GSTPI) enzyme activity has been reported in Barrett''s esophagus, and an inverse correlation was demonstrated between GST enzyme activity and tumor incidence in the gastrointestinal tract, but the role of GSTPI messengerRNA (mRNA) expression in Barrett''s esophagus and associated adenocarcinomas is uncertain. The purpose of this study was to investigate the role of GSTPI mRNA and protein expression in the development and progression of the Barrett''s metaplasia-dysplasia-adenocarcinoma sequence, and to investigate the potential of GSTPI quantitation as a biomarker in the clinical management of this disease. GSTPI mRNA expression levels, in relation to the housekeeping gene β-actin, were analyzed using a quantitative real-time reverse transcription–polymerase chain reaction method (TaqMan) in 111 specimens from 19 patients with Barrett''s esophagus without carcinoma (BE group), 21 patients with Barrett''s-associated adenocarcinoma (EA group), and a control group of 10 patients without evidence of Barrett''s esophagus or chronic gastroesophageal reflux disease. GSTPI mRNA expression was detectable in all 111 samples investigated. Analyzed according to histopathologic group, the median GSTPI mRNA expression was highest in normal squamous esophagus epithelium, intermediate in Barrett''s esophagus, and lowest in adenocarcinoma tissues (P < 0.001). The median GSTPI expression was significantly decreased in Barrett''s esophagus tissues compared to matching normal squamous esophagus from either the BE group (P = 0.001) or the EA group (P = 0.023). GSTPI expression levels in adenocarcinoma tissues were decreased compared to matching normal esophagus tissues from the patients with adenocarcinoma (P = 0.011). Furthermore, GSTPI mRNA expression values were significantly different between metaplastic, dysplastic, and adenocarcinoma tissues (P = 0.026). GSTPI expression levels were also significantly lower in histologically normal squamous esophagus tissues from patients with cancer (EA group) compared to both normal esophagus tissues from patients without cancer (BE group; P = 0.007) and normal esophagus tissues from the control group with no esophageal abnormality (P = 0.002). GSTPI protein expression was generally highest in the basal layer of normal squamous esophagus epithelium and lowest in adenocarcinoma cells, with Barrett''s cells showing intermediate staining intensity. Our results show that downregulation of GSTPI expression is an early event in the development of Barrett''s esophagus and esophageal adenocarcinoma. Loss of GSTPI expression may have an important role in the development and progression of this disease. ( J Gastrointest Surg 2002;6:359–367.) [ABSTRACT FROM AUTHOR]