The tylosis esophageal cancer (TOC) locus: more than just a familial cancer gene

Squamous Cell Carcinoma of the Esophagus

Esophageal squamous cell carcinoma (ESCC) is common in the developing world with decreasing incidence in developed countries and carries significant morbidity and mortality. Major risk factors for ESCC development include significant use of alcohol and tobacco. Screening for ESCC can be recommended in high-risk populations living in highly endemic regions. The treatment of ESCC ranges from endoscopic resection therapy or surgery in localized disease to chemoradiotherapy in metastatic disease, and prognosis is directly related to the stage at diagnosis. New immunotherapies and molecular targeted therapies may improve the dismal survival outcomes in patients with metastatic ESCC.

Performance of screening tests for esophageal squamous cell carcinoma: a systematic review and meta-analysis

BACKGROUND AND AIMS

This systematic review and meta-analysis aims to compare the pooled diagnostic accuracy of the currently available esophageal squamous cell carcinoma (ESCC) screening tests.

METHODS

A comprehensive literature search of Embase and Medline (up to October 31, 2020) was performed to identify eligible studies. We pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for ESCC screening tools using a bivariate random-effects model. The summary receiver operating characteristic curves with area under the curve (AUC) were plotted for each screening test.

RESULTS

We included 161 studies conducted in 81 research articles involving 32,209 subjects. The pooled sensitivity, specificity, and AUC of the major screening tools were respectively as follows: endoscopy (peroral endoscopy): .94 (95% confidence interval [CI], .87-.97), .92 (95% CI, .87-.95), and .97 (95% CI, .96-.99); endoscopy (transnasal endoscopy): .85 (95% CI, .70-.93), .96 (95% CI, .91-.98), and .97 (95% CI, .95-.98); microRNA: .77 (95% CI, .75-.80), .78 (95% CI, .75-.80), and .85 (95% CI, .81-.87); autoantibody: .45 (95% CI, .36-.53), .91 (95% CI, .89-.93), and .84 (95% CI, .81-.87); and cytology: .82 (95% CI, .60-.93), .97 (95% CI, .88-.99), and .97 (95% CI, .95-.98). There was high heterogeneity.

CONCLUSIONS

The diagnostic accuracy seemed to be comparable between cytology and endoscopy, whereas autoantibody and microRNAs bear potential as future noninvasive screening tools for ESCC. To reduce ESCC-related death in high-risk populations, it is important to develop a more accurate and less-invasive screening test.

Racial Disparities in Esophageal Cancer

Esophageal cancer is a deadly cancer. Advances in multimodal treatment have improved esophageal cancer outcomes. Advancements have not benefited all races equally. Major disparities in esophageal cancer outcomes exist. Minorities undergo fewer surgical resections of esophageal cancer and have poorer outcomes.

AJUBA: A regulator of epidermal homeostasis and cancer

The epidermis, outermost layer of the skin, is constantly renewing itself through proliferative and differentiation processes. These processes are vital to maintain proper epidermal integrity during skin development and homeostasis and for preventing skin diseases and cancers. The biological mechanisms that permit this balancing act are vast, where individual pathway regulators are known, but the exact regulatory control and cross-talk between simultaneously turning one biological pathway on and an opposing one off remain elusive. This review explores the diverse roles the scaffolding protein AJUBA plays during epidermal homeostasis and cancer. Initially identified for its role in promoting meiotic progression in oocytes through Grb2 and MAP kinase activity, AJUBA also maintains cytoskeletal tension permitting epidermal tissue development and responds to retinoic acid committing cells to initiate development of surface epidermal layer. AJUBA regulates proliferation of skin stem cells through Hippo and Wnt signalling and encourages mitotic commitment through Aurora-A, Aurora-B and CDK1. In addition, AJUBA also induces epidermal differentiation to maintain appropriate epidermal thickness and barrier function by activating Notch signalling and stabilizing catenins and actin during cellular remodelling. AJUBA also plays an imperative context-dependent tumor-promoting and tumor-suppressive role within epithelial cancers. AJUBA's abundant roles within the epidermis signify its importance as a molecular switchboard, vetting multiple signalling pathways to control epidermal biology.

miR-148a Regulates the Stem Cell-Like Side Populations Distribution by Affecting the Expression of ACVR1 in Esophageal Squamous Cell Carcinoma

Introduction

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor disease with high mortality and morbidity rates, especially for a terminal cancer. At present, the prognosis and treatment of ESCC cannot effectively control or inhibit the spread and proliferation of tumor cells. microRNAs, a class of small spliced RNAs, are essential in the regulation of tumorigenesis and tumor cell migration and proliferation. microRNAs interact with target mRNA to silence gene expression and degrade mRNA, thereby inhibiting the expression of tumor genes or impairing the expression of tumor suppressor genes.

Methods

A total of 20 human ESCC samples were collected from the Affiliated Tumor Hospital of Xinjiang Medical University. Eca109 and Kyse510 cells, which are ESCC cell lines, were subjected to FACS analysis to get side population (SP) cells and non-SP cells. Cell cycle and cell proliferation were analyzed by flow cytometry. Cell migration and invasion were detected using a transwell assay. Quantitative PCR and Western blot were performed to analyze the expression levels of ABCG2, KLF4, OCT4, and ACVR1, which are related to the stemness of stem cells. The target genes of hsa-miR-148a were predicted using TargetScan (version 7.2) and verified by a dual luciferase reporter assay. A chromatin immunoprecipitation (ChIP) assay was carried out to demonstrate direct interaction between miR-148a and ACVR1.

Results

The expression of miR-148a was significantly down-regulated in ESCC cells and significantly decreased in SP esophageal squamous cells when compared to the tumor cells. By analyzing the stem cell stemness of ESCC, overexpression of miR-148a decreased the expression of ABCG2, KLF4, SOX2, OCT4, and Nanog, indicating that miR-148a may regulate stem cell function. Target gene prediction and functional annotation of miR-148a suggested that miR-148a is involved in stem cell stemness of ESCC via ACVR1. Expression of the dual luciferase-labeled gene indicates that overexpression of miR-148a inhibits the expression of ACVR1, thereby affecting stem cell stemness.

Conclusion

miR-148a regulates the stem cell-like side populations distribution by inhibiting the expression of ACVR1 in ESCC. miR-148a may be a promising targeted therapy for ESCC.

Esophageal Cancer: An Updated Surveillance Epidemiology and End Results Database Analysis

Background

Esophageal cancer is the sixth leading cause of cancer-related deaths and the eighth most common cancer worldwide with a 5-year survival rate of less than 25%. Here we report the incidence, risk factors and treatment options that are available currently, and moving into the future.

Methods

We retrospectively analyzed the Surveillance Epidemiology and End Results (SEER) database made available by the National Cancer Institute in the USA. Specifically we extracted data from the years 2004 - 2015.

Results

In total we identified 23,804 patients with esophageal adenocarcinoma and 13,919 patients with esophageal squamous cell carcinoma. Males were at an increased risk of developing both types of esophageal cancer when compared to females. Most cases of adenocarcinoma were diagnosed as poorly differentiated grade III (42%), and most cases of squamous cell carcinoma were diagnosed as moderately differentiated grade II (39.5%). The most common stage of presentation for both adenocarcinoma (36.9%) and squamous cell (26.8%) carcinoma was stage IV. The worst outcomes for adenocarcinoma were noted with grade III tumors (hazard ratio (HR): 1.56, 95% confidence interval (CI): 1.44 - 1.68, P value: < 0.01), stage IV tumors (HR: 3.58, 95% CI: 3.33 - 3.85, P value: < 0.01) and those not treated with surgery (HR: 2.54, 95% CI: 2.44 - 2.65, P value: < 0.01). For squamous cell carcinoma, the worst outcomes were noted with grade III tumors (HR: 1.35, 95% CI: 1.23 - 1.49, P value: < 0.01), stage IV tumors (HR: 2.12, 95% CI: 1.94 - 2.32, P value: <0.01).

Conclusions

The incidence of esophageal adenocarcinoma in the USA is steadily on the rise. Conversely, the incidence of squamous cell carcinoma has been continually declining. While white males had an increased incidence of both types of esophageal cancer, a higher proportion of African Americans suffered from squamous cell carcinoma. Despite the wide spread use of proton pump inhibitors, adenocarcinoma continues to be a major public health concern.

The Molecular Biologic Basis of Esophageal and Gastric Cancers

Esophageal cancer and gastric cancer are leading causes of cancer-related mortality worldwide. In this article, the authors discuss the molecular biology of esophageal and gastric cancer with a focus on esophageal adenocarcinoma. They review data from The Cancer Genome Atlas project and advances in the molecular stratification and classification of esophageal carcinoma and gastric cancer. They also summarize advances in microRNA, molecular staging, gene expression profiling, tumor microenvironment, and detection of circulating tumor DNA. Finally, the authors summarize some of the implications of understanding the molecular basis of esophageal cancer and future directions in the management of esophageal cancer.

Screening for esophageal squamous cell carcinoma: recent advances

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer worldwide, with a high mortality due to advanced stage at diagnosis. Although most common in an area known as the Asian Esophageal Cancer Belt, which extends from the Caspian Sea to northern China, and in parts of Africa, high-risk populations also exist elsewhere in the world. Screening for ESCC has been practiced in a few geographic areas and high-risk populations, with varying levels of success. Esophageal squamous dysplasia is recognized as the precursor lesion for ESCC. Endoscopic screening for ESCC/esophageal squamous dysplasia is expensive and not sufficiently available in many high-risk regions. Recent advances in non-endoscopic screening enhanced by biomarker-based disease detection have raised the prospect of improved accuracy and availability of screening for esophageal squamous dysplasia and early stage ESCC. Development of a cost-effective, accurate, and well-tolerated screening test, if applied in endemic areas and high-risk populations, has the potential to reduce mortality from this deadly disease worldwide. In this review, we summarize recent developments in endoscopic and non-endoscopic screening modalities.

HPV, KRAS mutations, alcohol consumption and tobacco smoking effects on esophageal squamous-cell carcinoma carcinogenesis

Esophageal squamous-cell carcinoma (ESCC) is an invasive neoplastic disease generally associated with poor survival rates. The incidence of ESCC is characterized by marked geographic variation, with highest rates noted in developing Southeastern African, Central and Eastern Asian countries. In the developed Western European and North American regions where there is a low disease incidence, heavy alcohol and cigarette consumption constitute major risk factors. The toxic effects of both these risk factors cause chronic irritation and inflammation of the esophageal mucosa, while at the cellular level they further confer mutagenic effects by the activation of oncogenes (e.g., RAS mutations), inhibition of tumor-suppressor genes, and profound DNA damage. Viral infections, particularly with human papillomavirus, may activate specific antiapoptotic, proliferative and malignant cellular responses that may be intensified in combination with the effects of alcohol and tobacco. In countries with a high ESCC incidence, low socioeconomic status and an inadequate diet of poorly preserved food are combined with basic nutritional deficiencies and inadequate medical treatment. These conditions are favorable to the above-mentioned risk factors implicated in ESCC development, which may be present and/or habitually used in certain populations. New perspectives in epidemiological studies of ESCC development and its risk factors allow genome-wide research involving specific environments and habits. Such research should consist of adequately large and representative samples, should use newly designed informative genetic markers, and apply genomic variation analysis of the functional transcripts involved in malignant cell cycle regulation and neoplastic transformation in the multi-step process of ESCC carcinogenesis.

Non-acid gastro-oesophageal reflux is associated with squamous cell carcinoma of the oesophagus

INTRODUCTION

Squamous cell carcinoma of the oesophagus is a common cancer among South Africans. Due to the absence of effective screening and surveillance programme for early detection and late presentation, squamous cell carcinoma of the oesophagus is usually diagnosed at an advanced stage or when metastasis has already occurred. The 5-year survival is often quoted at 5%-10%, which is poor.

OBJECTIVES

To determine the association between oesophageal squamous cell carcinoma (OSCC) and non-acid gastro-oesophageal reflux disease.

METHODS

Study design: A cross-sectional case-control analytical study of patients referred to the Gastroenterology Division of Steve Biko Academic Hospital in Pretoria, South Africa. All patients had combined multichannel impedance and pH studies done and interpreted after upper gastroscopy using the American College of Gastroenterology guidelines by two clinicians.

RESULTS

Thirty-two patients with OSCC were recruited: non-acid reflux was found in 23 patients (73%), acid reflux in 2 patients (6%) and 7 patients (22%) had normal multichannel impedance and pH studies.Forty-nine patients matched by age, gender and race were recruited as a control group. Non-acid reflux was found in 11 patients (22%), acid reflux in 31 patients (63%) and 7 patients (14%) had normal multichannel impedance and pH monitoring study.

CONCLUSION

The significance of the association between non-acid reflux and OSCC was tested using χ2, and simple logistic regression was used to adjust for the effects of potential confounders.The OR of developing OSCC in patients with non-acid gastro-oesophageal reflux was 8.8 (95% CI 3.2 to 24.5, P<0.0001) in this South African group.Alcohol and smoking had no effect on these results.

Photodynamic therapy downregulates the function of regulatory T cells in patients with esophageal squamous cell carcinoma

Photodynamic therapy (PDT) by selective photosensitization of cancer cells and subsequent laser application results in local tumor necrosis. However, the effects of PDT on immune function, which may depend on the type of immune response, are controversial. We investigated the immunological changes induced by PDT and the effect of PDT on level and function of regulatory T cells (Treg) in patients with invasive esophageal squamous cell carcinoma (ESCC). We analyzed patient's blood samples before and after PDT. Blood CD4+CD25+CD127-FoxP3+ Treg levels were quantified by FACS, and Treg function was evaluated by coculture proliferation assays with T effector (Teff) cells. We found that PDT abrogated the suppressive capacity of peripheral Treg (Days 7 and 14, p = 0.016) but had no effect on Treg levels. The effect of PDT on Treg function at Day 7 was accompanied by slight but statistically significant increases in peripheral neutrophil granulocytes (p = 0.035) and monocytes (p = 0.013) and a statistically significant increase (approximately 18-fold) in serum IL-6 levels (p = 0.008). In conclusion, PDT abolished Treg function, possibly due to increased IL-6 levels in treated ESCC patients. This may be crucial for an improved therapeutic outcome.

HPV infection in esophageal squamous cell carcinoma and its relationship to the prognosis of patients in northern China

Purpose. Human papillomavirus (HPV) as a risk factor for esophageal squamous cell carcinoma (ESCC) has previously been studied, but importance of HPV status in ESCC for prognosis is less clear. Methods. A total of 105 specimens with ESCC were tested by in situ hybridization for HPV 16/18 and immunohistochemistry for p16 expression. The 5-year overall survival (OS) and progression-free survival were calculated in relation to these markers and the Cox proportional hazards model was used to determine the hazard ratio (HR) of variables in univariate and multivariate analysis. Results. HPV was detected in 27.6% (29) of the 105 patients with ESCC, and all positive cases were HPV-16. Twenty-five (86.2%) of the 29 HPV-positive tumors were stained positive for p16. HPV infected patients had better 5-year rates of OS (65.9% versus 43.4% among patients with HPV-negative tumors; P = 0.002 by the log-rank test) and had a 63% reduction in the risk of death (adjusted HR = 0.37, 95% CI = 0.16 to 0.82, and P = 0.01). Conclusions. HPV infection may be one of many factors contributing to the development of ESCC and tumor HPV status is an independent prognostic factor for survival among patients with ESCC.

Oesophageal carcinoma

Oesophageal carcinoma affects more than 450,000 people worldwide and the incidence is rapidly increasing. Squamous-cell carcinoma is the predominant form of oesophageal carcinoma worldwide, but a shift in epidemiology has been seen in Australia, the UK, the USA, and some western European countries (eg, Finland, France, and the Netherlands), where the incidence of adenocarcinoma now exceeds that of squamous-cell types. The overall 5-year survival of patients with oesophageal carcinoma ranges from 15% to 25%. Diagnoses made at earlier stages are associated with better outcomes than those made at later stages. In this Seminar we discuss the epidemiology, pathophysiology, diagnosis and staging, management, prevention, and advances in the treatment of oesophageal carcinoma.

Cytoglobin: biochemical, functional and clinical perspective of the newest member of the globin family

Since the discovery of cytoglobin (Cygb) a decade ago, growing amounts of data have been gathered to characterise Cygb biochemistry, functioning and implication in human pathologies. Its molecular roles remain under investigation, but nitric oxide dioxygenase and lipid peroxidase activities have been demonstrated. Cygb expression increases in response to various stress conditions including hypoxia, oxidative stress and fibrotic stimulation. When exogenously overexpressed, Cygb revealed cytoprotection against these factors. Cygb was shown to be upregulated in fibrosis and neurodegenerative disorders and downregulated in multiple cancer types. CYGB was also found within the minimal region of a hereditary tylosis with oesophageal cancer syndrome, and its expression was reduced in tylotic samples. Recently, Cygb has been shown to inhibit cancer cell growth in vitro, thus confirming its suggested tumour suppressor role. This article aims to review the biochemical and functional aspects of Cygb, its involvement in various pathological conditions and potential clinical utility.

Factors associated with carcinoma of the oesophagus at Mulago Hospital, Uganda

BACKGROUND

In Uganda, as in many other parts of the world cancer of the oesophagus (CAE) is on the rise. Squamous cell carcinoma and adenocarcinoma are the common subtypes. Risk factors for this cancer have been identified but not studied systematically in Uganda. Identification of these factors would enable establishment of preventive measures.

OBJECTIVE

To determine the prevalence, histological features and associated factors for CAE among patients referred to the endoscopic unit of Mulago hospital, Kampala, Uganda.

METHODS

We performed a 1-year cross-sectional study in 2004 and 2005 of all patients presenting for oesophageal-gastro-duodenoscopy (EGD) at Mulago Hospital. Demographic characteristics, behavioural practices, endoscopy findings and histology results where biopsies were performed were collected using a study tool. Data analysis was done using STATA 8 statistical package.

RESULTS

Two hundred nineteen patients were enrolled in the study, three were excluded because they could not tolerate the endoscopy procedure. Fifty five (19%) of the 287 had histologically proven CAE. Squamous cell carcinoma was found in 100% of tumours of the upper third, 91% middle third, and 73% lower third of the oesophagus. Four patients had a histological diagnosis of adenocarcinoma of the oesophagus. Factors that were associated with CAE included age (OR 1.63, CI 1.34-1.98, p value <0.001), smoking (OR 3.63, CI 1.82-7.23, p value <0.001) and gender (OR 2.17, CI 1.07-4.41, p value 0.032).

CONCLUSION

Many patients referred for EGD in Uganda had esophageal cancer most of which were.squamous cell type. Smoking, male gender and older age were risk factors. Preventive measures should target stopping smoking.

Advances in endoscopic imaging of the esophagus

The introduction of flexible fiberoptic endoscopy in the 1960s was a major step forward in the diagnosis and management of various esophageal disorders. Since then, there has been steady progress in the development of novel gastrointestinal endoscopy techniques. Magnification and high-resolution endoscopy, chromoendoscopy, narrow-band imaging, autofluorescence imaging, and confocal laser endomicroscopy are some of the recent advances that have shown promise in the diagnosis of squamous cell carcinoma, gastroesophageal reflux disease, Barrett's esophagus, and adenocarcinoma of the esophagus. The purpose of this review is to summarize the recent advances in endoscopic imaging of the esophagus and their practical application for the gastroenterologist.

Genetics of gastroesophageal cancer: paradigms, paradoxes, and prognostic utility

Hereditary diffuse gastric cancer and tylosis are autosomal dominant cancer susceptibility syndromes. Accumulating evidence also suggests a genetic contribution to Barrett's esophagus and adenocarcinoma, traditionally considered acquired disorders. In this article we review the current knowledge on the genetic mechanisms underlying hereditary diffuse gastric cancer, tylosis, and Barrett's esophagus. Hereditary diffuse gastric cancer is a paradigm for hereditary cancer susceptibility syndromes with E-cadherin implicated as the dominant oncogene in up to one-third of cases. Tylosis in contrast remains the paradox as whilst the putative abnormality has been localized to the long arm of chromosome 17, sequencing of this region has failed to reveal a disease causing mutation. In the case of Barrett's esophagus and adenocarcinoma, although a validated specific disease-associated gene is yet to be identified, the increasing body of evidence of a possible genetic link is paving the way for subsequent prognostic studies such as AspECT (Aspirin Esomeprazole Chemoprevention Trial). For the clinician these advances in understanding are already having implications for practice in terms of improved screening and the stratification of management strategies. As the mechanisms continue to be defined, there is the real possibility that these mechanisms could be exploited or subverted in the design of new therapies. In the meantime, however, clinicians should undertake rigorous biopsy programs to ensure early invasive lesions are detected.

Expression of p53 and its homolog, p73, in HPV DNA positive oesophageal squamous cell carcinomas

Several studies have detected human papilloma virus (HPV) DNA in squamous cell carcinoma of the oesophagus (OSCC). In this study, we analysed OSCC specimens from 114 patients for the presence of HPV DNA, and p53 and p73 expression. HPV DNA was detected in 44.7% of cases, with the low risk HPV11 occurring most frequently. p53 and p73 expression was detected in 70% and 61.4% of cases, respectively. There was no correlation between expression of p53, p73 or HPV infection and tumour grade, or between p53 expression and the presence of HPV DNA. There was, however, significant correlation between p73 expression and the presence of HPV DNA (p<0.01) and p53 and p73 co-expression (p<0.001), as well as co-expression of p53 and p73 with HPV status (p<0.05). These data support previous studies suggesting a role for HPV infection in OSCC and also indicate that HPV infection and p53 and p73 overexpression are not mutually exclusive. In addition, the data implicate a role for p73 in OSCC and suggest a complex interaction between p53, p73 and HPV in the aetiology of the disease.

Prevention and management of early esophageal cancer

Early esophageal cancer is defined by its limitation to the esophageal mucosa and submucosa. It has become a curable malignant disease, in sharp contrast to the dismal prognosis of esophageal cancer at advanced stages, which still represents the majority of patients. Understanding the risk factors, establishing surveillance programs for patients at risk, and developing preventative interventions such as dietary and lifestyle changes or pharmacologic interventions hold the potential of reducing the incidence of the disease and of shifting the stage distribution toward early cancer. Endoscopic ultrasound examination is pivotal for distinguishing early from advanced stages of the disease because it allows for accurate assessment of tumor infiltration and regional lymph node involvement. The therapeutic mainstay for early esophageal cancer remains surgery. New, less invasive surgical techniques are being tested that are associated with less morbidity and mortality than standard radical esophagectomies. For patients who are not candidates for surgery, definitive chemoradiation is a viable alternative. New endoscopic ablation techniques, such as endoscopic mucosa resection and photodynamic therapy, are potential alternatives to surgery in patients with cancers limited to the mucosa. For patients with adenocarcinoma of the gastroesophageal junction with submucosal involvement, adjuvant chemoradiation should be considered because of its potential to increase survival.

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Primary adenocarcinomas of lower esophagus, esophagogastric junction and gastric cardia: in special reference to China

Gastric cardia adenocarcinoma (GCA) is an under-studied subject. The pathogenesis, molecular changes in the early stage of carcinogenesis and related risk factors have not been well characterized. There is evidence, however, that GCA differs from cancer of the rest of the stomach in terms of natural history and histopathogenesis. Adenocarcinomas of the lower esophagus, esophagogastric junction (EGJ) and gastric cardia have been given much attention because of their increasing incidences in the past decades, which is in striking contrast with the steady decrease in distal stomach adenocarcinoma. In China, epidemiologically, GCA shares very similar geographic distribution with esophageal squamous cell carcinoma (SCC), especially in Linzhou (formerly Linxian County), Henan Province, North China, the highest incidence area of esophageal SCC in the world. Historically, both GCA and SCC in these areas were referred to as esophageal cancer (EC) by the public because of the common syndrome of dysphagia. In Western countries, Barrett's esophagus is very common and has been considered as an important precancerous lesion of adenocarcinoma at EGJ. Because of the low incidence of Barrett's esophagus in China, it is unlikely to be an important factor in early stage of EGJ adenocarcinoma development. However, Z line up-growth into lower esophagus may be one of the characteristic changes in these areas in early stage of GCA development. Whether intestinal metaplasia (IM) is a premalignant lesion for GCA is still not clear. Higher frequency of IM observed at adjacent GCA tissues in Henan suggests the possibility of IM as a precancerous lesion for GCA in these areas. Molecular information on GCA, especially in early stage, is very limited. The accumulated data about the changes of tumor suppressor gene, such as p53 mutation, and ontogeny, such as C-erbB2, especially the similar alterations in GCA and SCC in the same patient, indicated that there might be some similar risk factors, such as nitrosamine, involved in both GCA and SCC in Henan population. The present observations also suggest that GCA should be considered as a distinct entity.

Mutant deoxynucleotide carrier is associated with congenital microcephaly

The disorder Amish microcephaly (MCPHA) is characterized by severe congenital microcephaly, elevated levels of alpha-ketoglutarate in the urine and premature death. The disorder is inherited in an autosomal recessive pattern and has been observed only in Old Order Amish families whose ancestors lived in Lancaster County, Pennsylvania. Here we show, by using a genealogy database and automated pedigree software, that 23 nuclear families affected with MCPHA are connected to a single ancestral couple. Through a whole-genome scan, fine mapping and haplotype analysis, we localized the gene affected in MCPHA to a region of 3 cM, or 2 Mb, on chromosome 17q25. We constructed a map of contiguous genomic clones spanning this region. One of the genes in this region, SLC25A19, which encodes a nuclear mitochondrial deoxynucleotide carrier (DNC), contains a substitution that segregates with the disease in affected individuals and alters an amino acid that is highly conserved in similar proteins. Functional analysis shows that the mutant DNC protein lacks the normal transport activity, implying that failed deoxynucleotide transport across the inner mitochondrial membrane causes MCPHA. Our data indicate that mitochondrial deoxynucleotide transport may be essential for prenatal brain growth.

Role of molecular biology in the follow-up of patients who have Barrett's esophagus

At present, the follow-up of patients who have Barrett's esophagus (BE) should occur within the setting of an endoscopic biopsy surveillance program and with the frequency of surveillance as proposed by the American College of Gastroenterology. In the future, patients who have BE will be further stratified according to their risk for progression to invasive carcinoma. This stratification will permit the development of more rational surveillance programs. Models that incorporate epidemiologic risk factors, reflux symptoms, and endoscopic and histologic findings will likely include panels of biomarkers for further stratification of patients as low, intermediate, or high risk. Therefore, the challenge over the next decade will be to define the role of molecular markers in endoscopic surveillance strategies and to identify additional clinically relevant molecular markers for prognosis as intermediate markers for chemoprevention and as molecular targets for novel gene therapies.