Differential expression of apoptosis related proteins and nitric oxide synthases in Epstein Barr associated gastric carcinomas.
OBJECTIVE
To determine the incidence of Epstein Barr virus associated gastric carcinoma (GC) in Brazil and compare the expressions of apoptosis related proteins and nitric oxide synthases between EBV positive and negative gastric carcinoma.


METHODS
In situ hybridization of EBV-encoded small RNA-1 (EBER-1) and PCR was performed to identify the presence of EBV in GCs. Immunohistochemistry was used to identify expressions of bcl-2, bcl-xl, bak, bax, p53, NOS-1, NOS-2, and NOS-3 proteins in 25 EBV positive GCs and in 103 EBV negative GCS.


RESULTS
12% of the cases of GC (25/208) showed EBER-1 and EBNA-1 expression. The cases were preferentially of diffuse type with intense lymphoid infiltrate in the stroma. EBV associated GCs showed higher expression of bcl-2 protein and lower expression of bak protein than in EBV negative GCs. Indeed, expressions of NOS-1 and NOS-3 were frequently observed in EBV associated GCs.


CONCLUSIONS
Our data suggest that EBV infection may protect tumor cells from apoptosis, giving them the capacity for permanent cell cycling and proliferation. In addition, EBV positive GCs show high expression of constitutive NOS that could influence tumor progression and aggressiveness.
Begnami
Maria D
MD
Department of Pathology, Hospital do Câncer A C Camargo, São Paulo, SP 01519010, Brazil. mariadirlei@gmail.com
Montagnini
Andre L
AL
Vettore
Andre L
AL
Nonogaki
Sueli
S
Brait
Mariana
M
Simoes-Sato
Alex Y
AY
Seixas
Andrea Q A
AQ
Soares
Fernando A
FA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D020031:Epstein-Barr Virus Infections / Q000150:complications*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D012367:RNA, Viral / Q000096:biosynthesis; D013274:Stomach Neoplasms / Q000150:complications* / Q000201:enzymology / Q000473:pathology* / Q000821:virology*
C099537:Epstein-Barr virus encoded RNA 1; D012367:RNA, Viral; D019001:Nitric Oxide Synthase