Qualitative analysis of Adenomatous Polyposis Coli promoter: hypermethylation, engagement and effects on survival of patients with esophageal cancer in a high risk region of the world, a potential molecular marker. BMC Cancer 2009 Jan 17;9:24
Date
01/20/2009Pubmed ID
19149902Pubmed Central ID
PMC2637891DOI
10.1186/1471-2407-9-24Scopus ID
2-s2.0-60549105721 (requires institutional sign-in at Scopus site) 51 CitationsAbstract
BACKGROUND: Squamous cell carcinoma of esophagus (SCCE) occurs at a high incidence rate in certain parts of the world. This feature necessitates that different aspects of the disease and in particular genetic characteristics be investigated in such regions. In addition, such investigations might lead to achievement of molecular markers helpful for early detection, successful treatment and follow up of the disease. Adenomatous Polyposis Coli (APC) promoter hypermethylation has been shown to be a suitable marker for both serum and solid tumors of adenocarcinoma of esophagus. We investigated the status of APC promoter hypermethylation in Iranian patients, compared the results with the former studies, and evaluated its applicability as a candidate molecular marker by examining association between survival of SCCE patients and APC promoter methylation.
METHODS: For evaluating the status of APC promoter hypermethylation and its association with SCCE, a qualitative methylation specific PCR (MSP) was used. DNA was extracted and digested with an appropriate restriction enzyme, treated with sodium bisulfite in agarose beads and amplified in two-step PCR reaction by applying either methylated or unmethylated promoter specific primers. Universally methylated DNA and methylase treated blood DNA of healthy donors were used as positive controls as well. Survival of patients was followed up for two years after treatment and survival rate of patients with methylated APC promoter was compared with that of unmethylated patients.
RESULTS: Assessment of APC promoter methylation revealed that normal tissues were unmethylated, while twenty out of forty five (44.4%) tumor tissues were hypermethylated either in one or both alleles of APC. Among the tissues in which methylation was detected, seven were hypermethylated in both alleles while the other thirteen were hypermethylated in one of the two alleles of APC. Analyzing two-year survival rate of patients with respect to promoter hypermethylation showed a lower rate of survival for patients with methylated APC promoter following their treatment. Further investigation into the association between promoter hypermethylation and tumor differentiation status indicated that patients with well differentiated tumors were more likely to develop promoter hypermethylation.
CONCLUSION: Observing similar level of APC promoter hypermethylation in patients with SCCE in this high risk region and comparing it with other parts of the world could support the hypothesis that a common molecular mechanism might be involved in tumorigenesis of SCCE. In addition, the higher rate of two-year survival for patients with unmethylated APC promoter as well as its relationship with tumor differentiation would suggest that this tumor suppressor could be an appropriate candidate molecular marker for evaluating tumor malignancy and predicting survival of patients subsequent to treatment.
Author List
Zare M, Jazii FR, Alivand MR, Nasseri NK, Malekzadeh R, Yazdanbod MAuthor
Mohammadreza Alivand DPhil Postdoctoral Fellow in the Biochemistry department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultAged
Aged, 80 and over
Carcinoma, Squamous Cell
DNA Methylation
DNA Primers
Esophageal Neoplasms
Female
Gene Amplification
Genes, APC
Genetic Markers
Humans
Iran
Male
Middle Aged
Polymerase Chain Reaction
Promoter Regions, Genetic
Young Adult
