[Effects of LMP-1 expression on neoplastic cell proliferation and apoptosis in nasopharyngeal carcinoma].
OBJECTIVE
To investigate the effects of LMP-1 expression on neoplastic cell proliferation and apoptosis in untreated nasopharyngeal carcinoma (NPC).


METHODS
Biopsies from 55 untreated NPC cases were collected. EBERs was detected by in situ hybridization. PCNA, LMP-1 and bcl-2 were detected by immunohistochemistry method. Cell apoptosis was demonstrated by TUNEL (TdT-mediated dUTP-x nick end labeling) kit.


RESULTS
(1) The positive LMP-(1) expression rate was 27/55 (49.1%). The median PI (PCNA Index) of LMP-1 positive cases (90.0%) was higher than that of LMP-1 negative cases (80.0%) and the p value was less than 0.05 by rank sum (rs) test. (2) The median TI (TUNEL Index) of LMP-1 positive cases (16.2 per high power field) was also higher than that of LMP-1 negative cases (10.4 per high power field) and the p value was less than 0.05 by rs test. (3) As for the bcl-2 expression percentages, no correlation was found between LMP-1 positive and negative cases. (4) A positive rank correlation existed between PI and TI (rs = 0.368 1, P < 0.01), but no correlation was found between TI and bcl-2 expression percentage.


CONCLUSIONS
(1) NPC with LMP-1 expression have higher levels of PI, maybe resulting from the promotional effect of LMP-1 on cell proliferation. (2) NPC with LMP-1 expression also have a higher level of TI, indicating that LMP-1 can induce cell apoptosis, which could not be blocked by bcl-2 expression. The authors suggest that LMP-1 expression may exert a dual action on neoplastic cell proliferation and apoptosis in untreated nasopharyngeal carcinoma.
Li
Z
Z
Department of Pathology, Sun Yat-sen University of Medical Sciences, Guangzhou 510089.
Zong
Y
Y
D017209:Apoptosis; D002455:Cell Division; D020031:Epstein-Barr Virus Infections / Q000473:pathology / Q000821:virology; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000821:virology; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics; D014763:Viral Matrix Proteins / Q000096:biosynthesis*
C037662:EBV-associated membrane antigen, Epstein-Barr virus; C099537:Epstein-Barr virus encoded RNA 1; C106732:Epstein-Barr virus encoded RNA 2; D018809:Proliferating Cell Nuclear Antigen; D019253:Proto-Oncogene Proteins c-bcl-2; D012367:RNA, Viral; D014763:Viral Matrix Proteins