p53 overexpression in the multistep process of esophageal carcinogenesis

Gastric cancer prevention targeted on risk assessment: Gastritis OLGA staging

Gastric cancer (GC) ranks among the most lethal epithelial malignancies, and its striking mortality rate prompts a global prevention strategy. Helicobacter pylori (H. pylori) gastritis is the main GC promoter, and the 2014 Global Kyoto conference recognized H. pylori gastritis as a (treatable) infectious disease. It is therefore plausible that any large-scale intervention for H. pylori eradication would result in cleansing the world of the fifth cause of cancer-related death. Atrophic gastritis is the cancerization field in which GCs (both intestinal and diffuse histotypes) mainly develop. Discontinuing the inflammatory cascade triggered by H. pylori is tantamount to preventing GC. For patients (still infected or eradicated) who have already developed gastric atrophy, the severity/topography of the atrophic changes correlates with their cancer risk. Gastritis OLGA (Operative Link for Gastritis Assessment) staging consistently ranks the atrophy-associated cancer risk, providing a solid clinical/biological rationale for establishing patient-specific surveillance programs. By combining primary and secondary prevention strategies, gastric cancer is a preventable disease.

Gastritis staging as a clinical priority

The elective background for gastric adenocarcinoma is the atrophic transformation of the gastric mucosa. The extent of mucosal atrophy basically parallels the risk of developing gastric cancer. This means that either noninvasive (serology) or invasive (endoscopy/histology) methods enabling the atrophic transformation to be quantified can be used theoretically to assess a given patient's gastric cancer risk. This review aims to focus on the reliability of histology gastritis Operative Link for Gastritis Assessment -staging system for assessing the 'personalized' cancer risk in individuals with (atrophic) gastritis.

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.

The molecular landscape of colitis-associated carcinogenesis

In spite of the well-established histopathological phenotyping of IBD-associated preneoplastic and neoplastic lesions, their molecular landscape remains to be fully elucidated. Several studies have pinpointed the initiating role of longstanding/relapsing inflammatory insult on the intestinal mucosa, with the activation of different pro-inflammatory cytokines (TNF-α, IL-6, IL-10, IFN-γ), chemokines and metabolites of arachidonic acid resulting in the activation of key transcription factors such as NF-κB. Longstanding inflammation may also modify the intestinal microbiota, prompting the overgrowth of genotoxic microorganisms, which may act as further cancer promoters. Most of the molecular dysregulation occurring in sporadic colorectal carcinogenesis is documented in colitis-associated adenocarcinoma too, but marked differences have been established in both their timing and prevalence. Unlike sporadic cancers, TP53 alterations occur early in IBD-related carcinogenesis, while APC dysregulation emerges mainly in the most advanced stages of the oncogenic cascade. From the therapeutic standpoint, colitis-associated cancers are associated with a lower prevalence of KRAS mutations than the sporadic variant. Epigenetic changes, including DNA methylation, histone modifications, chromatin remodeling, and non-coding RNAs, are significantly involved in colitis-associated cancer development and progression. The focus now is on identifying diagnostic and prognostic biomarkers, with a view to ultimately designing patient-tailored therapies.

Trp53 haploinsufficiency modifies EGFR-driven peripheral nerve sheath tumorigenesis

Malignant peripheral nerve sheath tumors (MPNSTs) are genetically diverse, aggressive sarcomas that occur sporadically or in association with neurofibromatosis type 1 syndrome. Reduced TP53 gene expression and amplification/overexpression of the epidermal growth factor receptor (EGFR) gene occur in MPNST formation. We focused on determining the cooperativity between reduced TP53 expression and EGFR overexpression for Schwann cell transformation in vitro (immortalized human Schwann cells) and MPNST formation in vivo (transgenic mice). Human gene copy number alteration data, microarray expression data, and TMA analysis indicate that TP53 haploinsufficiency and increased EGFR expression co-occur in human MPNST samples. Concurrent modulation of EGFR and TP53 expression in HSC1λ cells significantly increased proliferation and anchorage-independent growth in vitro. Transgenic mice heterozygous for a Trp53-null allele and overexpressing EGFR in Schwann cells had a significant increase in neurofibroma and grade 3 PNST (MPNST) formation compared with single transgenic controls. Histological analysis of tumors identified a significant increase in pAkt expression in grade 3 PNSTs compared with neurofibromas. Array comparative genome hybridization analysis of grade 3 PNSTs identified recurrent focal regions of chromosomal gains with significant enrichment in genes involved in extracellular signal-regulated kinase 5 signaling. Collectively, altered p53 expression cooperates with overexpression of EGFR in Schwann cells to enhance in vitro oncogenic properties and tumorigenesis and progression in vivo.

A common p53 mutation (R175H) activates c-Met receptor tyrosine kinase to enhance tumor cell invasion

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive forms of human cancer with poor prognosis due to late diagnosis and metastasis. Common genomic alterations in ESCC include p53 mutation, p120ctn inactivation, and overexpression of oncogenes such as cyclin D1, EGFR, and c-Met. Using esophageal epithelial cells transformed by the overexpression of EGFR and p53(R175H), we find novel evidence of a functional link between p53(R175H) and the c-Met receptor tyrosine kinase to mediate tumor cell invasion. Increased c-Met receptor activation was observed upon p53(R175H) expression and enhanced further upon subsequent EGFR overexpression. We inhibited c-Met phosphorylation, resulting in diminished invasion of the genetically transformed primary esophageal epithelial cells (EPC-hTERT-EGFR-p53(R175H)), suggesting that the mechanism of increased invasiveness upon EGFR and p53(R175H) expression may be the result of increased c-Met activation. These results suggest that the use of therapeutics directed at c-Met in ESCC and other squamous cell cancers.

Fhit, E-cadherin, p53, and activation-induced cytidine deaminase expression in endoscopically resected early stage esophageal squamous neoplasia

BACKGROUND AND AIM

Abnormal expression of Fragile Histidine Triad (Fhit), E-cadherin and p53 is observed in esophageal squamous cell carcinoma. It has recently been reported that aberrant expression of activation-induced cytidine deaminase (AID) in gastric epithelium leads to the accumulation of nucleotide alterations in the p53 gene. However, little is known about the association between these molecular events and the clinicopathological characteristics of early stage esophageal squamous neoplasia, especially in endoscopically resected tumors.

METHODS

Esophageal squamous neoplasias (n = 49) comprising nine cases of low-grade intraepithelial neoplasia (LGIN), 22 of high-grade intraepithelial neoplasia/carcinoma in situ (HGIN/CIS) and 18 of invasive cancers, were endoscopically resected. Their expression of the tumor-related proteins: Fhit, E-cadherin, p53 and AID was assessed using immunohistochemical methods, and the relationship between protein expression and clinicopathological data was examined.

RESULTS

Reduced or absent Fhit and E-cadherin expression was detected in 22% and 0% of LGIN cases, 73% and 14% of HGIN/CIS cases, and 94% and 61% of invasive cancer cases, respectively, showing progressive increases during neoplastic progression (Fhit: P < 0.01, E-cadherin: P < 0.01). Although p53 and AID were overexpressed in these samples, no change in their expression occurred during neoplastic progression. Moreover, p53 expression was not significantly associated with AID expression.

CONCLUSIONS

These results indicate that a decrease in Fhit and E-cadherin expression could be related to the development and progression of esophageal squamous neoplasia, and that the expression of p53 was independent of aberrant AID expression in the early stage of esophageal carcinogenesis.

Copy-neutral loss of heterozygosity at the p53 locus in carcinogenesis of esophageal squamous cell carcinomas associated with p53 mutations

PURPOSE

LOH at the p53 locus has been reported to be associated with esophageal squamous cell carcinogenesis. The aim of this study is to identify potential mechanisms resulting in LOH around the p53 locus in its carcinogenesis.

EXPERIMENTAL DESIGN

We investigated 10 esophageal cancer cell lines and 91 surgically resected specimens, examining them for LOH at the p53 locus on chromosome 17. We examined the p53 gene by using microsatellite analysis, comparative genomic hybridization (CGH), FISH, and single-nucleotide polymorphism-CGH (SNP-CGH).

RESULTS

In an analysis of specimens by microsatellite markers, a close positive correlation was found between p53 mutations and LOH at the p53 locus (P < 0.01). Although four cell lines were found to be homozygous for p53 mutations, LOH at the p53 locus was not detected by CGH. Among two p53 mutant cancer cell lines and five p53 mutant/LOH cancer specimens analyzed by FISH, both the cell lines and four of the specimens exhibited no obvious copy number loss at the p53 locus. SNP-CGH analysis, which allows both determination of DNA copy number and detection of copy-neutral LOH, showed that LOHs without copy number change were caused by whole or large chromosomal alteration.

CONCLUSIONS

LOH without copy number change at the p53 locus was observed in p53 mutant esophageal squamous cell carcinomas. Our data suggest that copy-neutral LOH occurring as a result of chromosomal instability might be the major mechanism for inactivation of the intact allele in esophageal squamous cell carcinogenesis associated with p53 mutation.

Neoplasia without dysplasia: lessons from Barrett esophagus and other tubal gut neoplasms

CONTEXT

Classic pathology teaching emphasizes that neoplastic lesions of the gastrointestinal tract are characterized by architectural and cytologic abnormalities that distinguish it from normal tissue. Recent studies suggest that many important-and in some cases clonal-molecular abnormalities that lead to dysregulation of cell proliferation and differentiation (neoplasia) occur before morphologic expression of dysplasia.

OBJECTIVE

To summarize the biologic and pathologic features of preneoplastic conditions of the tubal gut that reveal evidence of neoplastic alteration, but without the traditional morphologic features of dysplasia, in order to provide guidance on how to identify these lesions. Particular attention is given to Barrett esophagus, a chronic inflammatory condition in which early molecular and morphologic events that drive carcinogenesis are best understood.

DATA SOURCES

Selected references and abstracts were obtained by a PubMed (US National Library of Medicine) search by using the search headings neoplasia, preneoplasia, dysplasia, adenoma, serrated polyps, and Barrett's esophagus between the years 1980 and 2009.

CONCLUSIONS

Many types of lesions throughout the tubal gut fulfill the most basic and classic principles of a neoplastic precursor lesion but lack conventional morphologic evidence of dysplasia and/or maintain the capacity for cell differentiation and maturation. All of these lesions, such as squamous dysplasia of the esophagus, dysplasia in Barrett esophagus, and hyperplastic/serrated polyps of the colon, represent early neoplastic precursor lesions but without conventional histologic features of dysplasia. It is important for pathologists to be aware of these lesions, both for diagnostic and prognostic purposes, but also so that future studies can be performed with regard to risk stratification of patients.

Insulin-like growth factor-binding protein-3 promotes transforming growth factor-{beta}1-mediated epithelial-to-mesenchymal transition and motility in transformed human esophageal cells

Insulin-like growth factor-binding protein (IGFBP)-3 is overexpressed frequently in esophageal squamous cell carcinoma. Yet, the role of IGFBP3 in esophageal tumor biology remains to be elucidated. We find that IGFBP3 facilitates transforming growth factor (TGF)-beta1-mediated epithelial-to-mesenchymal transition (EMT) in transformed human esophageal epithelial cells, EPC2-hTERT-EGFR-p53(R175H). In organotypic 3D culture, a form of human tissue engineering, laser-capture microdissection revealed concurrent upregulation of TGF-beta target genes, IGFBP3 and EMT-related genes in the cells invading into the stromal compartment. IGFBP3 enhanced TGF-beta1-mediated EMT as well as transcription factors essential in EMT by allowing persistent SMAD2 and SMAD3 phosphorylation. TGF-beta1-mediated EMT and cell invasion were enhanced by ectopically expressed IGFBP3 and suppressed by RNA interference directed against IGFBP3. The IGFBP3 knockdown effect was rescued by IGFBP3(I56G/L80G/L81G), a mutant IGFBP3 lacking an insulin-like growth factor (IGF)-binding capacity. Thus, IGFBP3 can regulate TGF-beta1-mediated EMT and cell invasion in an IGF or insulin-like growth factor 1 receptor-independent manner. IGFBP3(I56G/L80G/L81G) also promoted EMT in vivo in a Ras-transformed human esophageal cell line T-TeRas upon xenograft transplantation in nude mice. In aggregate, IGFBP3 may have a novel IGF-binding independent biological function in regulation of TGF-beta1-mediated EMT and cell invasion.

Epidermal growth factor receptor and mutant p53 expand an esophageal cellular subpopulation capable of epithelial-to-mesenchymal transition through ZEB transcription factors

Transforming growth factor-beta (TGF-beta) is a potent inducer of epithelial to mesenchymal transition (EMT). However, it remains elusive about which molecular mechanisms determine the cellular capacity to undergo EMT in response to TGF-beta. We have found that both epidermal growth factor receptor (EGFR) overexpression and mutant p53 tumor suppressor genes contribute to the enrichment of an EMT-competent cellular subpopulation among telomerase-immortalized human esophageal epithelial cells during malignant transformation. EGFR overexpression triggers oncogene-induced senescence, accompanied by the induction of cyclin-dependent kinase inhibitors p15(INK4B), p16(INK4A), and p21. Interestingly, a subpopulation of cells emerges by negating senescence without loss of EGFR overexpression. Such cell populations express increased levels of zinc finger E-box binding (ZEB) transcription factors ZEB1 and ZEB2, and undergo EMT on TGF-beta stimulation. Enrichment of EMT-competent cells was more evident in the presence of p53 mutation, which diminished EGFR-induced senescence. RNA interference directed against ZEB resulted in the induction of p15(INK4B) and p16(INK4A), reactivating the EGFR-dependent senescence program. Importantly, TGF-beta-mediated EMT did not take place when cellular senescence programs were activated by either ZEB knockdown or the activation of wild-type p53 function. Thus, senescence checkpoint functions activated by EGFR and p53 may be evaded through the induction of ZEB, thereby allowing the expansion of an EMT-competent unique cellular subpopulation, providing novel mechanistic insights into the role of ZEB in esophageal carcinogenesis.

Alcohol drinking, cigarette smoking, and the development of squamous cell carcinoma of the esophagus: molecular mechanisms of carcinogenesis

Esophageal cancer is the eighth most common incident cancer in the world and ranks sixth among all cancers in mortality. Esophageal cancers are classified into two histological types; esophageal squamous cell carcinoma (ESCC), and adenocarcinoma, and the incidences of these types show a striking variety of geographic distribution, possibly reflecting differences in exposure to specific environmental factors. Both alcohol consumption and cigarette smoking are major risk factors for the development of ESCC. Acetaldehyde is the most toxic ethanol metabolite in alcohol-associated carcinogenesis, while ethanol itself stimulates carcinogenesis by inhibiting DNA methylation and by interacting with retinoid metabolism. Cigarette smoke contains more than 60 carcinogens and there are strong links between some of these carcinogens and various smoking-induced cancers; these mechanisms are well established. Synergistic effects of cigarette smoking and alcohol consumption are also observed in carcinogenesis of the upper aerodigestive tract. Of note, intensive molecular biological studies have revealed the molecular mechanisms involved in the development of ESCC, including genetic and epigenetic alterations. However, a wide range of molecular changes is associated with ESCC, possibly because the esophagus is exposed to many kinds of carcinogens including alcohol and cigarette smoke, and it remains unclear which alterations are the most critical for esophageal carcinogenesis. This brief review summarizes the general mechanisms of alcohol- and smoking-induced carcinogenesis and then discusses the mechanisms of the development of ESCC, with special attention to alcohol consumption and cigarette smoking.

Does daily alcohol and/or cigarette consumption cause low-grade dysplasia, a precursor of esophageal squamous cell carcinoma?

BACKGROUND

Cigarette smoking and alcohol consumption are well-known risk factors for esophageal squamous cell carcinoma (ESCC), which has a very poor prognosis. Successful screening strategies for precursor lesions that can be targets for early detection and treatment are required to prevent ESCC.

METHODS

This is a prospectively cross-sectional study. To clarify whether daily smoking and/or alcohol consumption are risk factors for dysplasia, which is the initial lesion leading to ESCC. Lugol chromoendoscopy was performed in 1,345 eligible individuals. Six hundred ninety individuals had daily smoking and/or alcohol consumption; 655 individuals did not smoke and drink alcohol. The effects of smoking and alcohol consumption among high-grade dysplasia (HGD), low-grade dysplasia (LGD), and controls without dysplasia were evaluated using multiple logistic regression analysis.

RESULTS

Among 1,345 individuals, 17 HGD and 23 LGD lesions were confirmed histologically. The prevalence of both smoking and drinking consumption was significantly higher in HGD than in LGD individuals (age and sex adjusted odds ratio; 113.0, 95% confidence interval; 6.26), whereas no significant difference was seen in both consumption between LGD individuals and controls (odds ratio; 1.29, 95% confidence interval; 0.33-6.37). Approximately 70% of HGD individuals, but only 13% of LGD individuals, both smoked and consumed alcohol.

CONCLUSIONS

Daily cigarette and alcohol consumption were not the risk factors for LGD, however, consumption of both were high-risk factors for HGD. We suggest that documenting the difference of risk factors for LGD and HGD can assist in the development of effective screening, early detection, and prevention strategies for ESCC.

Pathology and pathobiology of the oesophageal carcinoma

Carcinoma of the oesophagus including carcinoma of gastro-oesophageal junction are rapidly increasing in incidence. During recent years there have been changes in the knowledge surrounding biology of the disease progression. Identification of dysplasia in mucosal biopsies is the most reliable pathologic indicator of an increased risk of development of squamous cell carcinoma and passes through the sequence of chronic esophagitis, low-grade and high-grade dysplasia and invasive carcinoma. Although Barrett's esophagus is a precursor to esophageal adenocarcinoma and have a well described sequence of carcinogenesis: the Barrett's metaplasia-dysplasia-adenocarcinoma sequence, not all patients with this disorder require intensive surveillance. The natural history of dysplasia is poorly understood, particularly in low-risk regions, and prospective follow-up studies are needed. Adjunctive methods to improve reproducibility, such as immunostaining for alpha-methylacyl-coenzyme A racemase (AMACR), show promise, but require confirmation in larger studies. In addition, several controversial methods such as detection of p16, p53, and DNA content abnormalities may help identify patients at particularly high risk for progression to cancer, but these techniques are not yet widely available for routine clinical application. More studies are needed to define other early nonmorphologic biomarkers for risk of squamous cell carcinoma. Recent evidence regarding the importance of several histopathologically derived prognostic factors, such as circumferential resection margin status and lymph node metastases are evaluated, including lymph node micrometastases and the sentinel node concept. With the rising use of multimodal treatments for oesophageal cancer it is important that the response of the tumour to this therapy can be carefully documented by histopathology.

Squamous dysplasia and other precursor lesions related to esophageal squamous cell carcinoma

Squamous cell carcinoma is the most common tumor of the esophagus worldwide, and it is believed to develop through a sequence of dysplastic precursor lesions, which can be detected both endoscopically and microscopically. There are no published guidelines regarding treatment for dysplasia; however, most authorities recommend increased endoscopic surveillance, with biopsies, for patients with flat low-grade dysplasia and endoscopic mucosal resection, endoscopic submucosal dissection, or esophagectomy for patients with high-grade dysplasia. Future studies are needed to define appropriate endoscopic surveillance frequencies for patients with premalignant lesions of the esophagus. This article discusses squamous dysplasia in detail, which is the most important and well-described risk factor for squamous cell carcinoma of the esophagus.

Serum p53 antibody as a predictor of early recurrence in patients with postoperative esophageal squamous cell carcinoma

It is reported that surveillance of serum p53 antibody (Ab) is a useful marker in detecting esophageal squamous cell carcinoma (ESCC). But there is little reported about prognostic significance of serum p53-Ab in postoperative patients with ESCC. The aim of this study is to evaluate the significance of preoperative serum p53-Ab as a marker of early recurrence after curative resection for ESCC. Enzyme-linked immunosorvent assay (ELISA) was used to analyze serum p53-Ab before treatment in 44 patients with ESCC. Carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC-Ag) were examined by immunoradiometric assay. The patients who were strongly positive and positive in serum p53-Ab were more likely to have early recurrence after curative resection than seronegative patients. There were no significant correlations between CEA, SCC-Ag positivity and early recurrence. We found that serum p53-Ab was useful to predict a risk of early recurrence after curative surgical resection for ESCC.

Study of p53 gene alteration as a biomarker to evaluate the malignant risk of Lugol-unstained lesion with non-dysplasia in the oesophagus

Mutations of the p53 gene are detected frequently in oesophageal dysplasia and cancer. It is unclear whether Lugol-unstained lesions (LULs) with non-dysplastic epithelium (NDE) are precursors of oesophageal squamous cell carcinoma (ESCC). To study the genetic alterations of NDE in the multistep process of oesophageal carcinogenesis, we determined the relationship between p53 mutations and LULs-NDE. Videoendoscopy with Lugol staining was performed prospectively in 542 oesophageal cancer-free subjects. Lugol-unstained lesions were detected in 103 subjects (19%). A total of 255 samples, including 152 LULs (NDE, 137; dysplasia, 15) and 103 paired samples of normal staining epithelium, were obtained from 103 subjects. After extraction of DNA and polymerase chain reaction analysis, direct sequencing method was applied to detect mutations of the p53 gene. The p53 mutation was detected in five of 137 samples with LULs-NDE (4%) and in five of 15 samples with dysplasia (33%). A hotspot mutation was found in 20% of LULs-NDE with p53 mutation and in 40% of dysplasia with p53 mutation. In contrast, no p53 mutations were found in 103 paired NDE samples with normal Lugol staining. In biopsy samples from oesophageal cancer-free individuals, the p53 missense mutations containing a hotspot mutation were found in NDE, which was identified as an LUL. These findings suggest that some LULs-NDE may represent the earliest state of oesophageal squamous cell carcinoma in Japanese individuals.

Mechanisms of genotoxin-induced transcription and hypermutation in p53

It is widely assumed that genotoxin-induced damage (e.g., G-to-T transversions) to the tumor suppressor gene, p53, is a direct cause of cancer. However, genotoxins also induce the stress response, which upregulates p53 transcription and the formation of secondary structures from ssDNA. Since unpaired bases are thermodynamically unstable and intrinsically mutable, increased transcription could be the cause of hypermutation, and thus cancer. Support for this hypothesis has been obtained by analyzing 6662 mutations in all types of cancer compared to lung and colon cancers, using the p53 mutation database. The data suggest that genotoxins have two independent effects: first, they induce p53 transcription, which increases the number of mutable bases that determine the incidence of cancer. Second, genotoxins may alter the fate, or ultimate mutation of a mutable base, for example, by causing more of the available mutable Gs to mutate to T, leaving fewer to mutate to A. Such effects on the fate of mutable bases have no impact on the incidence of cancer, as both types of mutations lead to cancer.

Expression of survivin, p53, and caspase 3 in Barrett's esophagus carcinogenesis

The regulation of apoptosis, as a distinctive form of programmed cell death, in multistep Barrett's esophagus (BE) carcinogenesis is poorly understood. The aim of this study was to investigate, in the intestinal metaplasia-dysplasia-carcinoma sequence, the role of survivin, an inhibitor of apoptosis; the p53 protein, a tumor suppressor gene involved in cell cycle control; and caspase 3, a protease-inducing apoptosis and inhibited by survivin. Immunohistochemical expression was tested in 40 cases of BE, including 11 low-grade and 19 high-grade dysplasias (HGD), and samples were obtained from 40 surgical specimens of esophagectomy performed for HGD or Barrett's adenocarcinoma. To define the deregulation time of the proteins, overexpression was evaluated in relation to the proliferative and/or maturative compartment. In BE, cytoplasmic expression of survivin and caspase 3 (100% of cases) was significantly higher than expression of p53 (25%). The latter increased with increasing grade of dysplasia. In BE, the expression of survivin, p53, and caspase 3 mainly involved the proliferative compartment, whereas in LGD and HGD, the 3 proteins were coexpressed in both proliferative and maturative compartments. These results indicate that survivin overexpression is an early event in the proliferative compartment of BE, preceding both p53 accumulation and dysplastic changes. Cytoplasmic survivin location may indicate an initial antiapoptotic, more than proliferative, role in the early phases of Barrett carcinogenesis. Expression of caspase 3 in BE and dysplasia may be ascribed to accumulation of the nonactivated form, as the antibody used detects both cleaved and uncleaved caspase 3.

p53 immunoexpression: an aid to conventional methods in the screening of precursor lesions of squamous esophageal cancer in patients at high-risk?

INTRODUCTION

Squamous cell carcinoma of the esophagus (SCCE) is diagnosed late and carries a poor prognosis. Lugol chromoendoscopy (LC) has being shown a useful tool in the management of patients at high risk for SCCE. Biomarkers such as p53 protein expression may be present in the esophageal mucosa long before esophageal symptoms or lesions appear and may aid in early diagnosis. This study was carried out to investigate the p53 immunoexpression in esophageal mucosa of smokers and alcohol consumers and study its relationship with different degrees of histological findings and the role of LC to detect areas that express p53.

METHODS

Group 1: One hundred and eighty-two asymptomatic subjects at high risk for SCCE (consumption of more than 80 g of ethanol and 10 cigarettes/day for at least 10 years). Group 2: Twenty healthy volunteers who neither smoked nor consumed alcohol. Both groups underwent upper GI endoscopy plus LC, with biopsies of the esophageal mucosa. Expression of p53 protein was compared to histological findings.

RESULTS

Group 1: There was 25/182 (14%) Lugol's unstained areas. p53 protein was expressed in a stepwise fashion according to the severity of the histological findings: normal mucosa (12/103 or 12%), mild esophagitis (6/43 or 14%), moderate esophagitis (4/18 or 22%), severe esophagitis (1/3 or 33%), low-grade dysplasia (4/11 or 36%), high-grade dysplasia (2/2 or 100%) and squamous cell carcinoma (2/2 or 100%) (p=0.001). Nine in 25 (36%) patients with Lugol's unstained areas and 22/157 (14%) with normal appearing Lugol's stained mucosa expressed p53. Group 2: There was no Lugol unstained areas. The histological analysis and immunohistochemistry for p53 were normal with the exception of two patients that presented mild esophagitis and expressed p53. Unstained areas were 3.5 times (95% CI: 1.2-9.6) more likely to express p53 then stained ones. Alcoholics/smokers were 1.9 (95% CI: 0.4-8) times more likely to express p53 than non-alcoholics/non smokers.

CONCLUSIONS

In this study, we find an association between histological alterations, p53 expression and Lugol's unstained areas. It may point to a higher risk for SCCE. Smokers and alcohol drinkers with normal mucosa or chronic esophagitis that express p53 protein may represent an unrecognized sub-group of individuals that may benefit from surveillance or intervention.

Risk of multiple squamous cell carcinomas both in the esophagus and the head and neck region

While multiple squamous cell carcinomas are often observed in the esophagus and the head and neck region and confound us about the favorable treatments, the reason why some patients are more likely to develop multiple cancers remains obscure. We statistically analyzed clinical factors in 203 patients with newly diagnosed squamous cell carcinoma, to assess the risk of multiple cancers for the establishment of an effective prevention and screening programs. Widespread epithelial oncogenic alterations were assessed as multiple lugol-voiding lesions (multiple LVL) using lugol chromoendoscopy. Genetic polymorphisms of alcohol dehydrogenase type 3 (ADH3) and aldehyde dehydrogenase type 2 (ALDH2) were identified by PCR-restriction fragment length polymorphism analysis. Forty patients had synchronous multiple cancers and the remaining 163 had solitary cancer. Presence of multiple LVL was the only independent risk factor for multiple cancers [relative risk (RR) = 67; 95%CI, 15-310]. Multiple LVL was observed in only smoking drinkers. Among them, a multivariate analysis demonstrated that the ALDH2 deficiency allele (RR = 5.7; 95%CI, 2.8-11.6) and the slow metabolizing ADH3 allele (RR = 1.9; 95%CI, 1.1-7.9) were the independent risk factors for multiple LVL. Combination of these alleles lead to increase the risk of multiple LVL. In conclusion, an episode of multiple LVL is a remarkable high risk for multiple cancers both at the esophagus and the head and neck region. The interaction between drinking and the ALDH2 deficiency allele increases the risk. In addition, the slow metabolizing ADH3 allele enhances the risk. Prohibiting the use of alcohol and early detection of cancer are strongly recommended for such individuals.

Squamous mucosal alterations in esophagectomy specimens from patients with end-stage achalasia

Achalasia is an esophageal motor disorder in which the primary morphologic changes are found in the myenteric plexus. However, a number of secondary alterations are characteristically found in esophagectomy specimens, including the mucosa. In addition, these patients are at increased risk of developing esophageal squamous cell carcinoma. We studied the squamous mucosal alterations in 35 esophagectomy specimens from patients with end-stage achalasia and compared them with those found in the squamous mucosa near the esophagogastric junction from pediatric autopsies (</=18 years) from patients with no known esophageal disease. A representative block was immunostained for p53 (DO7), CD3, and CD20. p53 immunoreactivity was graded as follows: 0 = no staining; 1+ = rare basal cell staining; 2+ = extensive basal cell staining; 3+ = suprabasilar staining. Intraepithelial lymphocyte counts were performed by counting five high power fields (HPF) and calculating an average/HPF. Ages of achalasia patients at esophagectomy ranged from 21 to 78 years (mean 56 years), including 20 men and 15 women. Disease duration ranged from 1 to 44 years (mean 17 years). In all cases the squamous mucosa from achalasia patients was markedly hyperplastic with papillomatosis and basal cell hyperplasia. p53 staining in the squamous mucosa from achalasia patients was significantly more common than in controls (32 of 35 [91%] vs 1 of 17 [6%]; p <0.05). In all achalasia cases CD3+ cells far outnumbered CD20+ cells. There was a significantly greater number of CD3+ cells in achalasia cases (range 32-239/HPF; mean 107/HPF) compared with controls (range 0.8-12/HPF; mean 6/HPF) (p <0.05). In conclusion, the squamous mucosa in esophagectomy specimens from patients with end-stage achalasia shows significant alterations including marked squamous hyperplasia, an increased frequency of p53 immunoreactivity, and increased numbers of CD3+ cells when compared with controls. These changes may be related to the increased risk of squamous cell carcinoma in these patients.

Human papillomavirus type, proliferative activity, and p53: potential markers of aggressive papillomatosis

CONTEXT

The predictive value of nuclear proliferation antigen (Ki-67), tumor suppressor gene product p53, and human papillomavirus type has not been evaluated for outcome of laryngeal papilloma.

OBJECTIVE

This study was designed to determine whether immunohistochemical analysis of Ki-67 and p53 and human papillomavirus typing by polymerase chain reaction are able to identify patients with a more aggressive course of laryngeal papillomatosis.

DESIGN

Immunohistochemistry and polymerase chain reaction were performed on archival, paraffin-embedded, laryngeal papillomatosis biopsy specimens at the time of diagnosis, at an intermediate time during treatment, and at the last procedure available. Staining indexes for Ki-67 and p53 were determined, and human papillomavirus type was analyzed for all biopsies.

PATIENTS

Twelve patients with recurrent laryngeal papillomatosis for at least 5 years were selected from patients treated at our institution during the last 20 years.

MAIN OUTCOME MEASURES

Separate analyses were conducted comparing average Ki-67 and p53 indexes against disease outcome, viral type, or average number of procedures per year. Associations were analyzed between virus type, average number of procedures per year, outcome, and histology.

RESULTS

No statistically significant associations were noted in Ki-67 or p53 indexes and outcome. Weak associations were noted for p53 indexes and procedures per year and virus type. Weak associations also were noted between virus type and development of neoplasia.

CONCLUSIONS

Our observations suggest that human papillomavirus typing may be helpful in identifying patients with aggressive recurrent laryngeal papillomatosis. The weak association between p53 indexes and procedures per year and virus type may have some predictive value in identifying aggressive lesions.

Detection of circulating anti-p53 antibodies in esophageal cancer patients

It has been reported that circulating anti-p53 antibodies (p53-Ab) in the serum are detected in some cancers. To investigate the usefulness of detecting p53-Ab, we measured the circulating p53-Ab in comparison with squamous cell carcinoma antigen (SCC-Ag) in patients with esophageal carcinoma. Serum specimens from 46 esophageal cancer patients (42 squamous cell carcinomas, 3 mucoepidermoid carcinomas and 1 basaloid squamous carcinoma) and 13 healthy subjects were studied. Serum p53-Ab was measured by an enzyme-linked immunosorbent assay. Surgically resected specimens from 43 patients were immunohistochemically stained for p53. Serum SCC-Ag was measured by a radioimmunoassay. The results were analyzed with the clinical data and outcome. Serum p53-Ab was detected in 13 (28%) of the 46 patients, but not in any of the healthy subjects. The positive rate was 0% (0/6) in stage I, 60% (3/5) in stage IIA, 30% (3/10) in stage IIB, 29% (7/24) in stage III and 0% (0/1) in stage IV. There was no difference in the outcome between the p53-Ab-positive and p53-Ab-negative patients. Immunohistochemically, 30 (70%) of the 43 specimens stained positively for p53. Serum p53-Ab was detected in 43% (13/30) of the patients with tumors which stained positively for p53. There was a close correlation between positivity for p53 immunostaining and positivity for p53-Ab (p<0.01). An elevated level of SCC-Ag was found in only 13%of the patients, and most patients positive for SCC-Ag already had advanced disease with lymph node metastasis and invasion to the adventitia. In conclusion, serum p53-Ab was detected in Japanese esophageal cancer patients at a frequency similar to that reported in Western countries. Serum p53-Ab may be a potentially useful molecular marker for detection and screening of esophageal cancer. Further studies of a large population may be required to elucidate the true diagnostic usefulness of measuring the serum p53-Ab.

Biological evaluation of undifferentiated carcinoma of the esophagus

BACKGROUND

Patients with undifferentiated carcinoma of the esophagus (UEC) are rare and have a poor prognosis compared with those with differentiated squamous cell carcinomas (DECs). We compared clinicopathological and biological features of UEC and DEC, with emphasis on markers for epithelial cell origin, proliferation, and cell-cell adhesion.

METHODS

Seven patients with UEC were compared with 21 with DEC. Immunohistochemical studies were performed by using monoclonal antibodies to cytokeratin, epithelial membrane antigen, p53, p21WAF1/CIP1, Ki-67, E-cadherin, desmoglein-1, and thrombomodulin.

RESULTS

Patients with UEC had a poorer prognosis because of hematogenous metastasis at the time of presentation (mean survival, 6.5 +/- 6.2 vs. 35.5 +/- 28.9 months; P < .05). Immunohistochemical findings for cytokeratin and epithelial membrane antigen suggest that some UECs had epithelial origins. The following immunohistochemical profile of UEC was consistent with its highly malignant properties: (1) reduced or negative expression of cell-cell adhesion molecules such as E-cadherin, desmoglein-1, and thrombomodulin, (2) high positive rate for p53 and Ki-67, and (3) negative expression of p21WAF1/CIP1.

CONCLUSIONS

The immunohistochemical findings for UEC showed its high cell-proliferative activity and a high potential for metastasis. Clinical features of UEC were supported by the results of immunohistochemical findings.

Role of p53 gene mutations in human esophageal carcinogenesis: results from immunohistochemical and mutation analyses of carcinomas and nearby non-cancerous lesions

In order to characterize p53 alterations in esophageal cancer and to study their roles in carcinogenesis, we performed gene mutation and immunohistochemical analysis on 43 surgically resected human esophageal specimens, which contain squamous cell carcinoma (SCC) and adjacent non-cancerous lesions, from a high-incidence area of Linzhou in Henan, China. A newly developed immunohisto-selective sequencing (IHSS) method was used to enrich the p53 immunostain-positive cells for mutation analysis. p53 gene mutations were detected in 30 out of 43 (70%) SCC cases. Among 29 SCC cases that were stained positive for p53 protein, 25 (86%) were found to contain p53 mutations. In five cases of SCC with homogeneous p53 staining, the same mutation was observed in samples taken from four different positions of each tumor. In a well differentiated cancer nest, p53 mutation was detected in only the peripheral p53-positive cells. In tumor areas with heterogeneous p53 staining, either the area stained positive for p53 had an additional mutation to the negatively stained area or both areas lacked any detectable p53 mutation. In the p53-positive non-cancerous lesions adjacent to cancer, p53 mutations were detected in seven out of 16 (47%) samples with basal cell hyperplasia (BCH), eight out of 12 (67%) samples with dysplasia (DYS), and six out of seven (86%) samples with carcinoma in situ (CIS). All mutations found in lesions with DYS and CIS were the same as those in the nearby SCC. In seven cases of BCH containing mutations, only three had the same mutations as the nearby SCC. The results suggest that p53 mutation is an early event in esophageal carcinogenesis occurring in most of the DYS and CIS lesions, and cells with such mutations will progress to carcinoma, whereas the role of p53 mutations in BCH is less clear.

Primary undifferentiated small cell carcinoma of the esophagus

We histologically examined undifferentiated small cell carcinoma of the esophagus from 21 patients and used immunohistochemical methods for detection of chromogranin A and p53, bcl-2, and Rb oncoproteins. Nine (43%) of the 21 carcinomas consisted solely of undifferentiated cells, but heterogeneous components of in situ or invasive squamous cell carcinoma or mucoepidermoid carcinoma were observed in the other 12 (57%) tumors. Squamous cell carcinoma in situ was observed in the mucosa adjacent to the main tumor in 7 (50%) of the 14 resected esophageal specimens. An admixture of invasive squamous cell carcinoma and undifferentiated carcinoma was observed in 4 (19%) of the 21 tumors, and mucoepidermoid carcinoma was noted in one case. Chromogranin A staining yielded a positive reaction in two (10%) undifferentiated components but was negative in all heterogeneous components. Multiple sites of p53 immunopositivity were seen in the undifferentiated component of 17 (81%) of the 21 tumors, as well as in the in situ or invasive squamous cell carcinoma or mucoepidermoid carcinoma components of 9 (75%) of 12 tumors. Seven (33%) of the 21 tumors showed positive bcl-2 immunoreactivity in the small cell component, but all of the heterogeneous components were negative. Rb protein immunoreactivity was observed in the small cell component of one (5%) case and in 9 (75%) of the 12 heterogeneous components. Six (86%) of the seven in situ squamous cell carcinoma components were positive for Rb protein. Eighteen (86%) of the 21 patients died within 24 months of diagnosis. Two patients (10%) who survived for more than 24 months had received chemotherapy.

Heterogeneity of p53 mutational status in esophageal squamous cell carcinoma

In esophageal squamous cell carcinoma, p53 gene mutations have been analyzed for inter- or intra-patient heterogeneity but only a few studies have investigated intratumoral heterogeneity. We investigated this question within individual esophageal cancers, and also in their lymph-node metastases in 8 cases. Analyzing the p53 gene sequence by direct sequencing of polymerase chain reaction products, we found heterogeneity for p53 mutations in the pre-invasive area in 3 esophageal cancers. In all areas sampled in the invasive portion of each cancer, the p53 mutational status was identical in a given tumor. In heterogeneous tumors, the invasive area showed one of the p53 mutations found in the pre-invasive area. In nodal metastases, the p53 mutation was identical to that in the invasive area of each primary tumor. These data suggest that the timing of p53 alteration is not as early as might have been expected, indicating that, in regard to p53 gene alteration, some esophageal cancers are composed of various subclones in the pre-invasive stage with invasiveness developing in one of them, which becomes predominant through clonal selection.

Radiotherapy for oesophagus carcinoma: the impact of p53 on treatment outcome

BACKGROUND AND PURPOSE

Wildtype p53 protein plays an important role in the cellular response to ionizing radiation and other DNA damaging agents and is mutated in many human tumours. We evaluated the relationship of the immunohistochemically determined p53 protein status and the disease control with radiotherapy alone for carcinoma of the oesophagus.

MATERIALS AND METHODS

Immunostaining for p53 protein was performed on paraffin-embedded specimens from 69 patients with adeno- and squamous cell carcinoma of the oesophagus. All patients were treated by radiotherapy exclusively, consisting of a combination of external irradiation and intraluminal brachytherapy, using two different dose levels.

RESULTS

Fifty-four percent (37/69) of the tumours showed overexpression of the p53 protein. No difference in pre-treatment parameters for p53-positive and p53-negative cases was detected. In multivariate analysis p53 was significantly associated with overall survival (OS) next to weight loss, tumour stage and N-stage. For metastatic-free survival (MFS) p53 status proved to be the sole independent prognostic factor. The influence of p53 on local recurrence-free survival (LRFS), however, was not as strong as on OS and MFS.

CONCLUSIONS

Immunohistochemically detected overexpression of mutated p53 protein in oesophagus carcinoma was an independent prognostic factor in a group of patients treated with radiotherapy alone.

Esophageal carcinoma originating in a duplication cyst: case report

The authors present the case report of a 61-year-old man, admitted with middle third squamous cell esophageal carcinoma. He was submitted to a curative gastroesophageal resection via a medium laparotomy and a right thoracotomy. An intrathoracic esophagogastric anastomosis was performed. The pathological analysis of the surgical specimen revealed a squamous cell carcinoma clearly originating from the epithelial lining of an esophageal duplication cyst. Immunohistochemitry showed p 53 staining of the tumor cells. The patient at 11 month follow up was asymptomatic.

p53 protein immunoexpression in esophageal squamous cell carcinoma and adjacent epithelium

BACKGROUND

Immunoreactivity for p53 tumor suppressor gene product is commonly found in human malignancies and some premalignant lesions, but its role in cancer development and its value as a marker of tumor biologic behavior is still unclear.

OBJECTIVES

This study was undertaken to assess p53 immunoexpression in esophageal squamous cell carcinoma and attempts to determine its correlation with morphological features associated with tumor behavior.

METHODS

Immunohistochemical study was performed on archival paraffin-embedded tissue of 37 esophageal squamous cell carcinomas and respective adjacent mucosa.

RESULTS

Twenty-one tumors (56.8%) demonstrated specific staining for p53. Sixteen areas of dysplasia were present in 14 out of the 35 cases. p53 positivity was found in one low-grade dysplasia and in six high-grade dysplasias. By univariate analysis, p53 immunoexpression correlated positively with local invasion (P = 0.01) and perineural spread (P = 0.04). Multivariate analysis with logistic regression showed that tumor invasion was the only factor that discriminated between p53 positive and p53 negative cases (OR: 15.6, P < 0.02). No relationship was found between p53 expression and tumor grade, DNA nuclear ploidy, and S-phase fraction.

CONCLUSIONS

These data suggest that p53 dysfunction may be implicated in early, preinvasive, stages of esophageal cancer as well as in the tumor progression related to a more invasive phenotype.

Wild-type but not mutant p53 activates the hepatocyte growth factor/scatter factor promoter

p53 transactivates the expression of a variety of genes by binding to specific DNA sequences within the promoter. We have investigated the ability of wild-type p53 and a non-DNA binding p53 mutant to activate the hepatocyte growth factor/scatter factor (HGF/SF) promoter using chloramphenicol acetyltransferase reporter constructs. We also used deletion sequences of the HGF/SF promoter to identify which regions, if any, were responsible for p53 binding. Our results show that wild-type but not mutant p53 activates the HGF/SF promoter when using -3000 and -755 bp upstream of the HGF/SF gene. This activation is lost when promoter sequences covering -365 and -239 bp are used. Analysis of the DNA sequence between -365 and -755 bp shows one putative p53 half-site with 80% homology to the consensus sequence and another half-site 3 bases downstream of this with 100% homology to the consensus sequence. In contrast to previously identified p53 binding DNA sequences, the downstream half-site is inverted. We propose that the HGF/SF promoter can be activated by wild-type p53 in vivo and that this could be as a result of a novel form of sequence-specific DNA binding.

The molecular epidemiology of p53 gene mutations in human breast cancer

The P53 tumor-suppressor gene is an advantageous tool for analyzing the molecular epidemiology of cancer. We describe the utility of the P53 gene as a 'mutagen test' and a prognostic indicator in breast cancer. Aspects of study design and methodology are discussed. Two major conclusions emerge: (1) there is an extraordinary diversity of mutational patterns among cohorts, hinting that the unique biology of mammary cells results in exposure to high doses of a diversity of ingested lipophilic mutagens; and (2) mutations in the P53 gene predict poor outcome in breast cancer.

From epithelial dysplasia to squamous carcinoma of the head and neck region: evolutive and prognostic histopathological markers

Ki67 immunoreactivity, p53 expression and apoptotic index were examined in 26 non-malignant lesions of the head and neck region, 22 dysplastic lesions of patients without evidence of head and neck carcinoma during follow-up time, 24 dysplastic lesions of patients who subsequently developed a squamous carcinoma in the same area, and 42 squamous cancer cases. A directly proportional relation between Ki67 immunoreactive pattern, apoptotic index and histological evolution from normal to dysplastic or neoplastic mucosa was evident. As far as p53 protein is concerned, its expression became higher and frequently transmural in neoplastic mucosa. A strict correlation between frequency and density of Ki67/p53 immunoreactivity according to invasive cell grading (ICG) scores and poor prognosis of patients were found. On the contrary, malignant cells highly expressing p53 seemed not to undergo apoptosis. Ki67 antigen and p53 protein detection in premalignant lesions and in carcinomas of the head and neck tract could be a useful marker for the management of patients at risk.