Cell proliferation, apoptosis, and apoptosis inhibition in malignant transformation of sinonasal inverted papilloma.
CONCLUSIONS
Increasing cell proliferation seems to be a very important factor in the development of inverted papilloma (IP). Apoptosis that was increased but weakly inhibited by Bcl-2 did not cause imbalance in the cell proliferation. Further increased cell proliferation in IP with dysplasia was an important mechanism of growth in dysplastic areas.


OBJECTIVE
The purpose of this study was to compare cell proliferation, apoptosis, and apoptosis inhibition by Bcl-2 in IP.


METHODS
Cell proliferation and apoptosis inhibition were detected by immunohistochemical staining with monoclonal antibodies to Ki-67 and Bcl-2. Apoptosis was detected by the transferase-mediated dUTP nick end-labeling (TUNEL) method.


RESULTS
As regards the Ki-67 index (KI), a significant increase was observed in IP with severe dysplasia, IP with carcinoma and invasive squamous cell carcinoma (SCC) compared with EP and IP with mild and moderate dysplasia. For the apoptosis index (AI), a significant increase was observed in IP with mild and moderate dysplasia compared with IP with carcinoma, invasive SCC and EP. For the Bcl-2 index (BI), a significant increase in expression was observed in IP with severe dysplasia and carcinoma and invasive SCC compared with control, EP and IP with mild dysplasia. Among IP, the KI (average 18.2%) was much higher than the AI (6.4%) and BI (4.1%).
Katori
Hideaki
H
Department of Otolaryngology, Yokohama City Minato Red Cross Hospital, 3-12-1 Shin-Yamashita, Naka-ku,Yokohama 231-8682, Japan. hhkatori@yahoo.co.jp
Nozawa
Akinori
A
Tsukuda
Mamoru
M
D017209:Apoptosis / Q000502:physiology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D002455:Cell Division / Q000502:physiology*; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D019394:Ki-67 Antigen / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009669:Nose Neoplasms / Q000473:pathology*; D018308:Papilloma, Inverted / Q000473:pathology*; D010255:Paranasal Sinus Neoplasms / Q000473:pathology*; D011230:Precancerous Conditions / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D012016:Reference Values
D019394:Ki-67 Antigen; D019253:Proto-Oncogene Proteins c-bcl-2