ABSTRACT
BACKGROUND AND OBJECTIVES: Human Papillomavirus (HPV) infection is a major risk factor for adenocarcinoma of the cervix. The high-risk types of the virus such as HPV16 and HPV18, which possess the E6 and E7 oncogenes, are responsible for approximately 50% of all cervical cancers. A rapid, sensitive and specific test has been proposed for detection of HPV to improve cervical cancer screening programs. OBJECTIVES: The aim of this study was to develop a fast PCR-ELISA assay designated as DIAPOPS (Detection of Immobilized Amplified Products in a One Phase System)for detection of HPV16 and HPV18 types in SCC samples and Pap smears. The type specific primers and probes were designed for PCR and PCR-ELISA. The amplified products were hybridized with a specific biotin-labeled probe for HPV18 inner amplicons. The hybrids were detected with peroxidase conjugated avidin. The test was performed on the paraffin block and Pap smear samples from the cervical cancer patients, and the results of DIAPOPS were compared with conventional PCR assay. RESULTS: The 70 samples (SCC and Pap smear samples) were collected from Imam Khomeini and Mirzakoochak Khan Hospitals in Tehran. The PCR-based method detected six HPV16 positive, three HPV18 positive and Two HPV33 positive samples. DIAPOPS results were compared with the conventional PCR results and they showed an increase in sensitivity of the DIAPOPS test. Not only all of them were confirmed by PCR-ELISA but also three samples that conventional PCR showed negative for HPV18, were demonstrated positive by the PCR-ELISA method. CONCLUSION: The results of the study show that modified PCR-ELISA assay is more sensitive to detect HPV types and can be used for diagnostic purposes.
ABSTRACT
Oesophageal cancer is one of the ten leading causes of cancer mortality worldwide. Earlier loss of heterozygosity (or allelic imbalance) studies have implicated regions on chromosomes 3p, 5q, 9p, 13q, 17p, 17q, and 18q in the development of sporadic oesophageal cancer and recent data have linked the familial tylosis with oesophageal cancer (TOC) gene-containing region on chromosome 17q25 with this cancer. We have studied allelic imbalance (AI) at microsatellite markers both closely linked to and distant from the TOC gene locus in 60 sporadic squamous cell oesophageal cancers from Iran and have investigated the most likely candidate gene by mutation analysis in these tumours. Forty-four out of these 60 samples (73%) show allelic imbalance at one or more loci within or adjacent to the TOC minimal region, while the highest incidence of AI was observed at the D17S2244 and D17S2246 loci (almost 70% AI in informative cases), correlating with the TOC minimal region. Analysis of the coding regions of a candidate gene in these tumours failed to show an equivalently high incidence of mutation, although two mutations and one polymorphism were observed. These data support and extend previous observations that the TOC region of chromosome 17q25 may be involved in the aetiology of the sporadic form of oesophageal cancer from a number of different geographical populations and suggest that the causative gene may be epigenetically silenced rather than mutated.
