Telomere shortening in the esophagus of Japanese alcoholics: relationships with chromoendoscopic findings, ALDH2 and ADH1B genotypes and smoking history

Telomere lengths in Barrett's esophagus as a precancerous lesion

BACKGROUND

We have reported that precancerous conditions and lesions invariably have shorter telomeres and associated chromosomal instability relative to normal tissue.

METHODS

Using the Q-FISH method and our original software, Tissue Telo, we estimated telomere lengths in cardiac- and intestinal-type mucosae in 48 cases of Barrett's esophagus (short-segment (SS) n = 18; long-segment (LS) n = 30).

RESULTS

There were no significant differences in telomere length between the cardiac and intestinal types in any of the 48 cases, suggesting that the presence or absence of goblet cells in the columnar segments is unrelated to telomere-dependent chromosomal instability in Barrett's esophagus. In LS Barrett's esophagus, telomeres were shorter in cardiac-type than in intestinal-type mucosa, suggesting that the former may play a more important role than the latter as a precancerous lesion in LS. Telomeres in cardiac-type mucosa were longer in SS than in LS, supporting the possibility that cardiac-type LS may pose a higher risk as a precancerous lesion than cardiac-type SS.

CONCLUSIONS

Although it has been considered that Barrett's carcinoma arises only from intestinal-type mucosa, our present findings support previous histogenetic studies suggesting that cardiac-type mucosa is more important as a precancerous condition in Barrett's esophagus than anticipated.

Telomere shortening in head and neck cancer: association between DNA demethylation and survival

A growing body of evidence indicates that telomere dysfunction is a biological marker of progression in several types of cancer. However, the association between head and neck squamous cell carcinoma (HNSCC) and telomere length (TL) remains unknown. We measured the absolute TL levels in a well-characterised dataset of 211 tumoral vs normal tissues obtained from the same patients by quantitative polymerase chain reaction assay. Normalised TL levels were significantly lower in tumour samples than in normal tissue (P < 0.001) and there was a positive correlation between tumour tissue and normal mucosal tissue (R² = 0.176, P < 0.001). We were able to distinguish two classes, one with a tumour/normal TL ratio ≤ 0.3 (38.4%), which showed clear telomere erosion, and the other with a tumour/normal TL ratio > 0.3 (61.6%), in which the TL was slightly shorter or longer than that in normal tissue. Notably, the tumour/normal TL ratio was correlated with the likelihood of disease recurrence (P = 0.002), the 5-hydroxymethylcytosine level (P = 0.043), and expression of the ten-eleven translocation (TET) gene (P = 0.043). Our findings show that TL shortening and subsequent low levels of 5-hydroxymethylcytosine and TET expression may contribute to development of HNSCC.

Secondary esophageal squamous cell carcinoma after hematopoietic stem cell transplantation

BACKGROUND

We evaluated cases of esophageal squamous cell carcinoma (ESCC) that developed after allogeneic hematopoietic stem cell transplantation (allo-HSCT) at our institution.

METHODS

Allo-HSCT was performed in 1534 patients (1776 cases) at our institution from 2001 to 2016. Overall, 602 patients were confirmed to have survived for 2 or more years and 154 underwent upper gastrointestinal endoscopy at least 1-year post-transplantation. ESCC was discovered in 17 patients (1.1%), 15 of whom had 31 lesions discovered at our institution (ESCC group). A retrospective comparative study was conducted with the remaining 137 patients for whom no ESCC was noted (non-ESCC group), and we also evaluated the clinicopathological characteristics of the ESCC group.

RESULTS

History of TBI (total body irradiation) and bone marrow transplant was significantly higher in the ESCC group. The mean time from transplantation to detection of ESCC was 82.3 months. Localization was upper thoracic in 12 cases, middle thoracic in 10, cervical in 4, lower thoracic in 3, and upper to lower thoracic in 2. Treatment comprised endoscopic submucosal dissection in 23 cases, surgery in 4, untreated due to worsening primary disease in 3, and chemoradiotherapy in 1.

CONCLUSIONS

In this study, lesions were located in the cervical to upper thoracic esophagus in approximately 60% of all secondary ESCC cases after allo-HSCT. History of TBI and bone marrow transplantation are high risk of ESCC, and proactive screening endoscopy is desirable.

Telomere shortening in the oral epithelium in relation to alcohol intake, alcohol dehydrogenase (ADH-1B), and acetaldehyde dehydrogenase (ALDH-2) genotypes and clinicopathologic features

BACKGROUND

Progressive telomere shortening with age or chronic inflammation may lead to genomic instability that characterizes the early stage of carcinogenesis. Certain risk factors, such as drinking alcoholic beverages or smoking, predispose the oral mucosa to squamous cell carcinoma. The ADH1B and ALDH2 genotypes can influence the risk of cancer due to alcohol drinking. In the present study, we analyzed chromosomal instability due to telomere shortening in the oral mucosa in relation to cancer risk factors.

DESIGN

Using our quantitative fluorescence in situ hybridization (Q-FISH) technique, we estimated telomere lengths (TL) in the background mucosa from 23 cases of mucosal carcinoma, 12 cases of oral epithelial dysplasia, and 21 non-neoplasia cases. ALDH2 and ADH1B genotypes were determined using DNA extracted from paraffin sections. We analyzed TL in relation to alcohol drinking, smoking, and cancer multiplicity.

RESULTS

Telomeres in the backgrounds of dysplasia and mucosal carcinoma were significantly shorter than in controls. In comparison with adult controls, telomeres were significantly (P = .038) shorter in the ADH1B less-active type (ADH1B*1/*1), but not (P = .841) in the ALDH2 inactive type (ALDH2*1/*2 or *2/*2). Cancer multiplicity and smoking had no significant relationship with TL.

CONCLUSION

Telomeres in the oral epithelium are shorter in cases of oral dysplasia or mucosal carcinoma than in non-neoplasia. Unlike the esophageal epithelium of alcoholics, they are also shorter in individuals with the less-active rather than the active ADH1B gene. Telomeres in the oral epithelium may be directly affected by alcohol drinking.

Telomere length of gallbladder epithelium is shortened in patients with congenital biliary dilatation: measurement by quantitative fluorescence in situ hybridization

BACKGROUND

Congenital biliary dilatation (CBD) is a congenital malformation involving both dilatation of the extrahepatic bile duct and pancreaticobiliary maljunction. Persistent reflux of pancreatic juice injures the biliary tract mucosa, resulting in chronic inflammation and higher rates of carcinogenesis in the biliary tract, including the gallbladder. Telomeres are repetitive DNA sequences located at the ends of chromosomes. Chromosomal instability due to telomere dysfunction plays an important role in the carcinogenesis of many organs. This study was performed to determine whether excessive shortening of telomeres occurs in the gallbladder mucosa of patients with CBD.

METHODS

Resected gallbladders were obtained from 17 patients with CBD, ten patients with cholecystolithiasis without pancreatic juice reflux, and 17 patients with normal gallbladders (controls) (median age of each group of patients: 37, 50, and 53 years, respectively). The telomere lengths of the gallbladder epithelium were measured by quantitative fluorescence in situ hybridization using tissue sections, and the normalized telomere-to-centromere ratio (NTCR) was calculated.

RESULTS

The NTCRs in the CBD, cholecystolithiasis, and control groups were 1.24 [interquartile range (IQR) 1.125-1.52], 1.96 (IQR 1.56-2.295), and 1.77 (IQR 1.48-2.53), respectively. The NTCR in the CBD group was significantly smaller than that in the cholecystolithiasis and control groups (p = 0.003 and 0.004, respectively), even in young patients.

CONCLUSIONS

Our findings indicate that telomere shortening in the gallbladder mucosa plays an important role in the process of carcinogenesis in patients with CBD. These results support the recommendation of established guidelines for prophylactic surgery in patients with CBD because CBD is a premalignant condition with excessive telomere shortening.

Association of TP53 codon 72 genotype polymorphism and environmental factors with esophageal squamous cell carcinoma in the Mongolian population of the Chinese region of Inner Mongolia

The present study analyzed the association of tumor protein p53 (TP53) Pro72Arg polymorphism with esophageal squamous cell carcinoma (ESCC) in the Mongolian population of Tongliao (Inner Mongolia, China). Restriction fragment length polymorphism-polymerase chain reaction was used to detect the genotype distribution of TP53 Pro72Arg polymorphism in 100 patients with ESCC and 50 healthy controls from the same population. Besides, the correlation between ESCC in Mongolian patients and various factors such as age, sex, cigarette smoking and alcohol consumption was analyzed. χ² test revealed significant associations between alcohol consumption (P=0.00006) and cigarette smoking (P=0.00076) and ESCC in Mongolian patients. Notably, the Pro72 allele was significantly enriched in patients with ESCC compared with its abundance in the healthy control group, and the genotype of Pro/Arg on p53 codon 72 was confirmed to exhibit a significant correlation with ESCC in Mongolian patients. The present study demonstrated that alcohol drinking and cigarette smoking were risk factors for ESCC in the Mongolian population. Mongolian patients who carry the partocular genotype of Arg/Pro or Pro/Pro on p53 codon 72 may be more likely to develop ESCC. Compared with the p53 codon 72 genotype Arg/Arg, the TP53 Pro72 allele increased the risk of ESCC in Mongolian patients by 1.659-fold.

Changes of telomere status with aging: An update

Accumulated data have shown that most human somatic cells or tissues show irreversible telomere shortening with age, and that there are strong associations between telomere attrition and aging-related diseases, including cancers, diabetes and cognitive disorders. Although it has been largely accepted that telomere attrition is one of the major causes of aging-related disorders, critical aspects of telomere biology remain unresolved, especially the lack of standardized methodology for quantification of telomere length. Another frustrating issue is that no potentially promising methods for safe prevention of telomere erosion, or for telomere elongation, have been devised. Here, we review several methods for quantification of telomere length currently utilized worldwide, considering their advantages and drawbacks. We also summarize the results of our recent studies of human cells and tissues, mainly using quantitative fluorescence in situ hybridization and Southern blotting, including those derived from patients with progeria-prone Werner syndrome and trisomy 21, and several strains of induced pluripotent stem cells. We discuss the possible merits of using telomere shortness as an indicator, or a new marker, for diagnosis of precancerous states and aging-related disorders. In addition, we describe newly found factors that are thought to impact telomere dynamics, providing a new avenue for examining the unsolved issues related to telomere restoration and maintenance.

Genetic polymorphisms of alcohol dehydrogense-1B and aldehyde dehydrogenase-2, alcohol flushing, mean corpuscular volume, and aerodigestive tract neoplasia in Japanese drinkers

Genetic polymorphisms of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) modulate exposure levels to ethanol/acetaldehyde. Endoscopic screening of 6,014 Japanese alcoholics yielded high detection rates of esophageal squamous cell carcinoma (SCC; 4.1%) and head and neck SCC (1.0%). The risks of upper aerodigestive tract SCC/dysplasia, especially of multiple SCC/dysplasia, were increased in a multiplicative fashion by the presence of a combination of slow-metabolizing ADH1B*1/*1 and inactive heterozygous ALDH2*1/*2 because of prolonged exposure to higher concentrations of ethanol/acetaldehyde. A questionnaire asking about current and past facial flushing after drinking a glass (≈180 mL) of beer is a reliable tool for detecting the presence of inactive ALDH2. We invented a health-risk appraisal (HRA) model including the flushing questionnaire and drinking, smoking, and dietary habits. Esophageal SCC was detected at a high rate by endoscopic mass-screening in high HRA score persons. A total of 5.0% of 4,879 alcoholics had a history of (4.0%) or newly diagnosed (1.0%) gastric cancer. Their high frequency of a history of gastric cancer is partly explained by gastrectomy being a risk factor for alcoholism because of altered ethanol metabolism, e.g., by blood ethanol level overshooting. The combination of H. pylori-associated atrophic gastritis and ALDH2*1/*2 showed the greatest risk of gastric cancer in alcoholics. High detection rates of advanced colorectal adenoma/carcinoma were found in alcoholics, 15.7% of 744 immunochemical fecal occult blood test (IFOBT)-negative alcoholics and 31.5% of the 393 IFOBT-positive alcoholics. Macrocytosis with an MCV≥106 fl increased the risk of neoplasia in the entire aerodigestive tract of alcoholics, suggesting that poor nutrition as well as ethanol/acetaldehyde exposure plays an important role in neoplasia.

Genetic variant rs401681 at 5p15.33 modifies susceptibility to lung cancer but not esophageal squamous cell carcinoma

BACKGROUND

The human 5p15.33 locus contains two well-known genes, the telomerase reverse transcriptase (TERT) and cleft lip and palate transmembrane 1-like (CLPTM1L) genes, which have been implicated in carcinogenesis. A common sequence variant, rs401681, located in an intronic region of CLPTM1L, has been reported to be associated with lung cancer risk based on genome-wide association study. However, subsequent replication studies in diverse populations have yielded inconsistent results. In addition, genetic variants at 5p15.33, including rs401681, have been shown to be involved in the susceptibility to multiple malignancies. Nevertheless, the role of these TERT-CLPTM1L variants in the etiology of esophageal squamous cell carcinoma (ESCC) remains unknown.

METHODS

We genotyped the rs401681 polymorphism using TaqMan methodology and analyzed its association with the risk of lung cancer and ESCC in a case-control study of 1,479 cancer patients (726 with lung cancer and 753 with ESCC) and 860 healthy individuals.

RESULTS

Logistic regression analyses revealed that rs401681 T genotypes were associated with a significantly decreased risk of lung cancer (CT vs. CC: adjusted OR=0.782, 95% CI=0.625-0.978, P=0.031; CT/TT vs. CC: adjusted OR=0.786; 95% CI=0.635-0.972, P=0.026). Stratification analysis by histology type indicated that rs401681 T genotypes were associated with a significantly reduced risk of both adenocarcinoma and squamous cell carcinoma. Furthermore, no significant association was observed between rs401681 and the risk of ESCC (CT vs. CC: adjusted OR=0.910, 95% CI=0.734-1.129, P=0.392; TT vs. CC: adjusted OR=0.897, 95%CI=0.624-1.290, P=0.558; CT/TT vs. CC: adjusted OR=0.908, 95% CI=0.740-1.114, P=0.355).

CONCLUSIONS

Our findings provide further evidence supporting rs401681 as a genetic variant associated with the risk of lung cancer. In addition, we investigated the correlation between the rs401681 variant and the risk of ESCC in a Han Chinese population, and our results suggest that this genetic variant may not be involved in ESCC risk.