Overexpression of cyclo-oxygenase 2 in squamous cell carcinoma of the hypopharynx.
Upregulation of cyclo-oxygenase 2 (COX-2) expression is frequently found in a variety of human cancers. In this study, we examined COX-2 expression in squamous cell carcinoma of the hypopharynx. COX-2 messenger RNA (mRNA) analyzed by reverse-transcription polymerase chain reaction was detected in 87% (20 of 23) of tumor tissues. Expression of COX-2 protein was examined by Western blot analysis. COX-2 protein levels were increased in tumor tissues and correlated with the expression level of mRNA. Immunohistochemical study was performed to detect the subcellular localization of COX-2. Our results showed that COX-2 was predominantly detected in cancer cells, and the staining pattern was cytoplasmic. Several histologically normal adjacent tissues obtained from these patients were also investigated. We found that COX-2 mRNA was detectable in these tissues. However, COX-2 mRNA and protein levels were lower in these tissues than in tumor specimens. In contrast, COX-2 mRNA and protein levels in normal oral mucosa obtained from healthy volunteers were very low or undetectable. The frequency of COX-2 overexpression was significantly higher in the N1-N3 group than in the N0 group. These results suggest that overexpression of COX-2 is linked with increased lymphatic invasion in hypopharyngeal carcinoma. Collectively, these results suggest that overexpression of COX-2 is a frequent phenomenon in hypopharyngeal carcinoma and may play a role in tumorigenesis of this cancer.
Peng
Jyh-Ping
JP
Department of Otolaryngology, Chang Gung University, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Kaohsiung, Taiwan, Republic of China.
Su
Chih-Ying
CY
Chang
Hui-Chiu
HC
Chai
Chee-Yin
CY
Hung
Wen-Chun
WC
D000328:Adult; D000368:Aged; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000473:pathology; D051546:Cyclooxygenase 2; D005260:Female; D006801:Humans; D007013:Hypopharynx / Q000201:enzymology* / Q000473:pathology; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D010610:Pharyngeal Neoplasms / Q000201:enzymology* / Q000473:pathology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012313:RNA / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D007527:Isoenzymes; D008565:Membrane Proteins; D012334:RNA, Neoplasm; D012313:RNA; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases