Detection of c-myc gene expression in nasopharyngeal carcinoma by nonradioactive in situ hybridization and immunohistochemistry.
OBJECTIVE
To investigate the c-myc gene expression in nasopharyngeal carcinoma (NPC) at mRNA and protein levels, and to evaluate the relationship between the degree of expression and the clinicopathological data.


METHODS
The expression of c-myc specific mRNA and protein was detected using in situ hybridization with digoxigenin-labeled probe and immunohistochemistry in 12 cases of normal nasopharyngeal epithelium (NE) and 48 cases of NPC. The intensity of staining for each sample was assessed as negative, weak, moderate and intense. Statistical analyses were performed using the Chi square test and the rank sum test.


RESULTS
For normal NE 41.7% (5/12) had weak (4/12) or moderate (1/12) staining for c-myc protein and 41.7% (5/12) had weak staining for c-myc mRNA. In contrast, 89.6% (43/48) of NPC showed some degree of c-myc protein positive and 87.5% (42/48) showed some degree of c-myc mRNA positive. In most samples, the expression of c-myc protein was consistent with that of c-myc mRNA. C-myc protein and mRNA expression levels in NPC were significantly higher than those in normal NE, and correlated with early recurrence, but they were not significantly related to patient's age, sex, EBVCA-IgA titre, disease stage, lymph node status and metastasis.


CONCLUSIONS
C-myc gene over-expression may be involved in the pathogenesis and early recurrence of NPC. Further studies are needed to substantiate the preliminary findings.
Luo
J
J
Department of Otolaryngology, Xiangya Hospital, Hunan Medical University, Changsha, China.
Xiao
J
J
Tao
Z
Z
Li
X
X
D015870:Gene Expression; D016259:Genes, myc; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D009303:Nasopharyngeal Neoplasms / Q000235:genetics*; D009364:Neoplasm Recurrence, Local; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis
D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger