title: THY1 is a candidate tumour suppressor gene with decreased expression in metastatic nasopharyngeal carcinoma.
abstract: Using oligonucleotide microarray analysis, THY1, mapping close to a previously defined 11q22-23 nasopharyngeal carcinoma (NPC) critical region was identified as showing consistent downregulated expression in the tumour segregants, as compared to their parental tumour-suppressing microcell hybrids (MCHs). Gene expression and protein analyses show that THY1 was not expressed in the NPC HONE1 recipient cells, tumour segregants, and other NPC cell lines; THY1 was exclusively expressed in the non-tumourigenic MCHs. The mechanism of THY1 gene inactivation in these cell lines was attributed to hypermethylation. Clinical study showed that in 65% of NPC specimens there was either downregulation or loss of THY1 gene expression. Using a tissue microarray and immunohistochemical staining, 44% of the NPC cases showed downregulated expression of THY1 and 9% lost THY1 expression. The frequency of THY1 downregulated expression in lymph node metastatic NPC was 63%, which was significantly higher than in the primary tumour (33%). After transfection of THY1 gene into HONE1 cells, a dramatic reduction of colony formation ability was observed. These findings suggest that THY1 is a good candidate tumour suppressor gene in NPC, which is significantly associated with lymph node metastases.
authors: Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (SAR), People's Republic of China.
authors: Hong Lok
authors: HL
authors: Lung
authors: Dhinoth Kumar
authors: DK
authors: Bangarusamy
authors: Dan
authors: D
authors: Xie
authors: Arthur Kwok Leung
authors: AK
authors: Cheung
authors: Yue
authors: Y
authors: Cheng
authors: Mande Kuppusamy
authors: MK
authors: Kumaran
authors: Lance
authors: L
authors: Miller
authors: Edison Tak-Bun
authors: ET
authors: Liu
authors: Xin-Yuan
authors: XY
authors: Guan
authors: Jonathan Shuntong
authors: JS
authors: Sham
authors: Yan
authors: Y
authors: Fang
authors: Liqiong
authors: L
authors: Li
authors: Nancy
authors: N
authors: Wang
authors: Alexey I
authors: AI
authors: Protopopov
authors: Eugene R
authors: ER
authors: Zabarovsky
authors: Sai Wah
authors: SW
authors: Tsao
authors: Eric J
authors: EJ
authors: Stanbridge
authors: Maria Li
authors: ML
authors: Lung
mesh_terms: D002277:Carcinoma / Q000235:genetics* / Q000473:pathology; D002880:Chromosomes, Human, Pair 11; D019175:DNA Methylation; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D016147:Genes, Tumor Suppressor; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000235:genetics; D046228:Microarray Analysis; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000473:pathology; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018800:Thy-1 Antigens / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured; D014410:Tumor Stem Cell Assay
chemical_list: D018800:Thy-1 Antigens