The expression of Bcl-2 family proteins and spontaneous apoptosis in laryngeal carcinomas.
Bcl-2 family proteins play an important role in the growth and biological behavior of tumors. This study aimed to determine Bcl-2 family proteins in laryngeal carcinoma and to examine their relationship with spontaneous apoptosis. The material studied was from 39 patients with laryngeal carcinoma. It was found that the expression of both Bak and Bax was lower in tumor tissues than in nontumor tissues. However, there was no difference in the expression of Bcl-2 between tumor and nontumor tissues. The frequency of spontaneous apoptosis was lower in tumor tissues than in nontumor tissues but was not significantly related to the expression of Bak, Bax, or Bcl-2. Bak was decreased in moderately differentiated tumors compared to well-differentiated tumors. In contrast to Bak, the expression of Bcl-2 was increased in moderately differentiated tumors compared to well-differentiated tumors. These results indicate that the reduction in Bak may be associated with an increase in tumor grade and dedifferentiation in laryngeal carcinomas. The lack of correlation between apoptosis and the expression of Bcl-2 family proteins suggests that spontaneous apoptosis in laryngeal carcinoma is a complex process and that molecules other than Bak, Bax, and Bcl-2 participate in it.
Chen
George G
GG
Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong. gchen@cuhk.edu.hk
Vlantis
Alexander C
AC
Chak
Ernest C W
EC
Liu
Han Ching
HC
Tong
Michael C F
MC
van Hasselt
Charles A
CA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000737:chemistry* / Q000473:pathology / Q000503:physiopathology; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D007822:Laryngeal Neoplasms / Q000737:chemistry* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D050998:bcl-2 Homologous Antagonist-Killer Protein / Q000032:analysis; D051028:bcl-2-Associated X Protein / Q000032:analysis
C494772:BAK1 protein, human; C494826:BAX protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein