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Objective: To assess alcohol dehydrogenase 3 (ADH3) polymorphism at position Ile349Val as indicator of risk factor for upper aerodigestive tract (UADT) cancer to verify its association with UADT cancer in nonalcoholic or nonsmoking individuals.Design: Cross-sectional study.Setting: Primary care or referral center. Patients:The study group consisted of 141 consecutive patients with newly diagnosed squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx admitted for surgical treatment. The comparison group consisted of 94 inpatients without cancer from the A. C. Camargo or other São Paulo (Brazil) hospital and 40 healthy individuals.Intervention: All participants were interviewed and data were collected using a structured questionnaire. After written informed consent was obtained, 20 mL of blood was collected in heparinized tubes. Main Outcome Measures:Odds ratio for ADH3 genotypes using logistic regression models.Results: After adjustment for sex, age, tobacco use, and history of cancer in first-degree family relatives, a significantly higher odds ratio for UADT cancer was observed among individuals with AA genotype and low cumulative alcohol consumption (Յ100 kg of ethanol) (odds ratio=3.8 [95% confidence interval, 1.5-9.7]). A 4-fold increase in odds ratio for UADT cancer among individuals with AA genotype and low tobacco consumption (Յ25 pack-years) was also found in the adjusted model. Conclusions:These results suggest that genotype AA may be a risk factor for UADT cancer, especially in individuals with low alcohol or tobacco consumption. However, further epidemiological case-control or cohort studies, preferably prospective, are needed to establish the exact role of ADH3 polymorphism and its association with the development of UADT cancers.

Measurement of telomerase activity in clinically obtained tumor samples may provide important information for use as both a diagnostic marker and a prognostic indicator for patient outcome. In order to evaluate telomerase activity in tumor tissue without radiolabeling the product, we developed a simple telomeric repeat amplification protocol-silver-staining assay that is less time-consuming, is safe and requires minimal equipment. In addition, we determined the sensitivity of the silverstaining method by using extracts of telomerase-positive thyroid carcinoma cell lines which were serially diluted from 5,000 to 10 cells. Telomerase activity was also assayed in 19 thyroid tumors, 2 normal controls and 27 bone marrow aspirates. The results indicate that the technique permits the detection of telomerase activity from 5000 to as few as 10 cells. We propose that it could be immediately applicable in many laboratories due to the minimal amount of equipment required. Correspondence

This work suggests that CDH1 gene methylation and H. pylori infection are frequent events in samples from Brazilian patients with chronic gastritis and reinforces the correlation between H. pylori infection and CDH1 inactivation in early steps of gastric tumorigenesis.

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We have developed a procedure for nonradioactive single strand conformation polymorphism analysis and applied it to the detection of point mutations in the human tumor suppressor gene p53. The protocol does not require any particular facilities or equipment, such as radioactive handling, large gel units for sequencing, or a semiautomated electrophoresis system. This technique consists of amplification of DNA fragments by PCR with specific oligonucleotide primers, denaturation, and electrophoresis on small neutral polyacrylamide gels, followed by silver staining. The sensitivity of this procedure is comparable to other described techniques and the method is easy to perform and applicable to a variety of tissue specimens. Key wordsA variety of methods have been proposed that facilitate rapid identification of genetic polymorphisms or somatic cell mutations, among which single strand conformation polymorphism (SSCP) is probably the most widely used. The original SSCP protocol uses radiolabeled oligonucleotides to generate a radioactive PCR product, which is then highly diluted, heat denatured, and analyzed by electrophoresis in a large (40 x 20 cm) nondenaturing gel (1). SSCP is based on the differential sequence-dependent electrophoretic mobilities of single-stranded DNA in nondenaturing polyacrylamide gels: changes in the sequence can cause a shift in the mobility of the analyzed conformers. This method, although sensitive, is both time consuming and cumbersome. There are several reports describing non-isotopic protocols for SSCP analysis (2,3), but these require expensive reagents and equipment such as small-format PhastGel, PhastSystem and Hydrolink-MDE, or the use of composite agarose gels (4).We developed a protocol for the detection of point mutations and deletions by a non-isotopic SSCP analysis on standard silver-stained polyacrylamide gels. The sequences used were PCR amplified regions of the p53 gene from samples of cervical carcinomas, penile carcinomas and gastric carcinomas where point mutations had been previously identified by isotopic SSCP and sequencing.PCR products were generated by specific primers and conditions for exons 5, 6, 7, 8 and 9 of the p53 gene, using the following primers: for exon 5, 5-TACTCCCCTGCC

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Alterations in the methylation status of genes may contribute to the progression of Chronic Myeloid Leukemia (CML). In this study, the methylation status in exon2 of SOCS-1 and promoter regions of both SOCS-1 and JUNB were evaluated in CML patients. The methylation status of these genes was analyzed using methylation-specific Polymerase Chain Reaction (MSP) in 30 samples from CML patients, 30 samples from these same patients after hematopoietic stem cell transplantation (HSCT) and 30 samples from healthy controls. The samples of CML patients presented methylation as follows: JUNB gene (3.3%), promoter region of the SOCS-1 gene (6.6%) and exon2 of the SOCS-1 gene (46.6%). The samples of the healthy individuals presented methylation (10%, P = 0.002) only in exon 2 of the SOCS-1 gene. After transplantation, patients presented alterations in the methylation status of the promoter region of the SOCS-1 gene (6.6%), exon2 of SOCS-1 (46.6%) and the promoter region of the JUNB gene (16.6%). Methylation of the promoter regions of the SOCS-1 gene and the JUNB gene is not a frequent event in CML. In contrast, SOCS-1 gene methylation in exon2 is a frequent event, susceptible to alterations in status after HSCT with possible implications for the progression of this disease.