[Detection of KIAA1173 gene expression in nasopharyngeal carcinoma tissues and cell lines on tissue microarray].

Background & Objective: Although the molecular etiology of nasopharyngeal carcinoma (NPC) is still unknown, studies showed that there are NPC-associated tumor suppressor genes residing in chromosome 3p21-22. KIAA1173 gene, locates at 3p22.1, was characterized as a new carcinoma-related gene, while its correlation to tumorigenesis of NPC hasn't been reported yet. This study was to detect the expression of KIAA1173 gene in NPC tissues and cell lines, and investigate its involvement in NPC.

Methods: KIAA1173 gene fragment (354 bp) was cloned, and the cDNA probe was prepared. The expression of KIAA1173 gene in 73 nasopharyngeal tissue samples (including 41 specimens of NPC, 18 atypical hyperplasia epithelia, and 14 normal nasopharyngeal mucosa epithelia) and 6 NPC cell lines (including CNE1, CNE2, HNE1, HNE2, 6-10B, and 5-8F) were examined using tissue microarray technique by in situ hybridization (ISH).

Results: The positive rates of KIAA1173 mRNA were 21.9% (9/41) in NPC, 83.3% (15/18) in atypical hyperplasia epithelia, 92.8% (13/14) in normal nasopharyngeal mucosa epithelia, and 0 in all NPC cell lines. Its strongly positive rate was significantly lower in NPC than in atypical hyperplasia epithelia and normal mucosa epithelia (0 vs. 38.9% and 64.3%, P < 0.001). In 38 specimens of NPC with infiltrated lymphocytes, the positive rate of KIAA1173 mRNA was significantly lower in cancer cells than in tumor infiltrating lymphocytes (23.7% vs. 44.7%, P < 0.05); the expression of KIAA1173 in cancer cells was negatively related to that in tumor infiltrating lymphocytes (kappa = -0.337, P < 0.05).

Conclusions: KIAA1173 gene is strongly expressed in normal nasopharyngeal mucosa epithelia, but down-regulated in NPC. It may be associated with the tumorigenesis of NPC. Tissue microarray;