Expression of the ALK protein by anaplastic large-cell lymphomas correlates with high proliferative activity

✍ Scribed by Lorenzo Leoncini; Stefano Lazzi; Donatella Scano; Antonina Mura; Angela Onida; Giovannino Massarelli; Piero Tosi; Paolo Barbini; Gabriele Cevenini; Maria Rita Massai; Stefano Pileri; Brunangelo Falini; Antonio Giordano; Rainer Kraft; Jean A. Laissue; Hans Cottier

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: French
• Weight: 303 KB
• Volume: 86
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(20000615)86:6<777::aid-ijc4>3.0.co;2-d

✦ Synopsis

A variable fraction of anaplastic large-cell lymphomas (AL-CLs) exhibits a t(2;5)(p23;q35) translocation that results in expression of the chimeric hyperphosphorylated protein NPM-ALK (p80). Tumor cells expressing NPM-ALK exhibit markedly enhanced proliferative activity, but comparative cellular kinetic studies on ALK ؉ (ALK lymphomas) and ALK - lymphomas are lacking. The present study showed that ALK ؉ lymphomas, detected with the monoclonal antibody ALKc (n ‫؍‬ 17), had significantly higher average values for the proliferation-associated parameters mitotic index, ana/telophase index, growth index (x ؋ mitotic index -apoptotic index, assuming x ‫؍‬ 3), percentages of Ki-67 ؉ cells and fraction of cells expressing cyclin A or B or the cell cycle-regulatory protein p34 cdc2 than did ALK -ALCLs (n ‫؍‬ 15). Whether this intense proliferative activity contributes to the good response to chemotherapy and favorable outcome of ALK ؉ ALCLs remains to be assessed in a larger series of patients. Our findings support the notion that ALK ؉ and ALK -ALCLs are 2 distinct disease entities.