Myanmar Health Sciences Research Journal
Volume 30, Number 1
TITLE: Genotypic Analysis of Epstein-Barr Virus (EBV) in Nasopharyngeal Carcinoma Patients
AUTHOR: Moh Moh Htun1*, Chaw Su Hlaing2, Myat Mon Oo1, Kay Thi Aye1, Aung Zaw Latt1, Soe Aung3, Hlaing Myat Thu1, Khin Pyone Kyi3 & Kyaw Zin Thant1
SOURCE: Myanmar Health Sciences Research Journal, Vol. 30, No. 1, 2018
ABSTRACT: Nasopharyngeal carcinoma (NPC) is endemic in certain populations, 0.6% of all cancers in the world. It occurs at high incidence in Southeast Asia, Southern China and North Africa. In Myanmar, the prevalence of NPC is gradually rising yearly and it is one of the common head and neck cancer in Yangon General Hospital (YGH). Epstein-Barr virus (EBV) is a member of the Herpesviridae family. It is a well-known causative agent in NPC and mainly infect in lymphocytes and epithelial cells. The polymerase chain reaction (PCR) was used to study DNA extracted from the blood samples of 35 histologically confirmed NPC patients. The commonest age group was 51-60 years in both gender and male was more common than female (1.5:1). The most common histological type was poorly differentiated squamous cell carcinoma (SCC) (45.7%) and other histological types were non-keratinized carcinoma (20%), undifferentiated anaplastic carcinoma (17.2%), moderately differentiated SCC (11.4%) and well differentiated SCC (5.7%) according to World Health Organization (WHO) classification. Primers were directed to conserved regions of the EBV genome encoding Epstein-Barr nuclear antigen 1(EBNA1) region. Specific EBV amplification (EBV-DNA positive) was found in 5 samples of NPC patients (14.3%) at 262 bp. The purified PCR products were carried out to do genetic sequencing by using ABI genetic analyzer. These isolates were found to be EB virus (Herpesviridae genotype 4) and firstly detected in blood samples of nasopharyngeal carcinoma patients in Myanmar. The new Myanmar EBV sequences were analyzed with a group of 14 previously published EBV strain sequences including 8 from China, 5 from Australia and one from Japan within 2006-2016. A phylogenetic tree was generated and the new Myanmar EBV strains were recorded that was different from other isolates these countries. Cancer treatment for early stage of NPC is good response but 70-80% of NPC is found in advanced or metastatic state. EBV DNA may be currently related biomarker in NPC which allows to one of the indicators for early diagnosis, better prognosis, treatment response and recurrent of disease during cancer therapy.
SUBJECT HEADINGS: Nasopharyngeal carcinoma (NPC), Epstein-Barr virus (EBV), Genotypic analysis