Droplet digital PCR analysis of NOTCH1 gene mutations in chronic lymphocytic leukemia

作者：Minervini Angela; Minervini Crescenzio Francesco; Anelli Luisa; Zagaria Antonella; Casieri Paola; Coccaro Nicoletta; Cumbo Cosimo; Tota Giuseppina; Impera Luciana; Orsini Paola; Brunetti Claudia; Giordano Annamaria; Specchia Giorgina; Albano Francesco^*

来源：Oncotarget, 2016, 7(52): 86469-86479.

DOI：10.18632/oncotarget.13246

• NOTCH1
• chronic lymphocytic leukemia
• droplet digital PCR
• IGHV mutational status
• molecular monitoring

In chronic lymphocytic leukemia (CLL), NOTCH1 gene mutations (NOTCH1(mut)) have been associated with adverse prognostic features but the independence of these as a prognostic factor is still controversial. In our study we validated a c.7541-7542delCT NOTCH1 mutation assay based on droplet digital PCR (ddPCR); we also analyzed the NOTCH1(mut) allelic burden, expressed as fractional abundance (FA), in 88 CLL patients at diagnosis to assess its prognostic role and made a longitudinal ddPCR analysis in 10 cases harboring NOTCH1(mut) to verify the FA variation over time. Our data revealed that with the ddPCR approach the incidence of NOTCH1(mut) in CLL was much higher (53.4%) than expected. However, longitudinal ddPCR analysis of CLL cases showed a statistically significant reduction of the NOTCH1(mut) FA detected at diagnosis after treatment (median FA 11.67 % vs 0.09 %, respectively, p = 0.01); the same difference, in terms of NOTCH1(mut) FA, was observed in the relapsed cases compared to the NOTCH1(mut) allelic fraction observed in patients in complete or partial remission (median FA 4.75% vs 0.43%, respectively, p = 0.007). Our study demonstrated a much higher incidence of NOTCH1(mut) in CLL than has previously been reported, and showed that the NOTCH1(mut) allelic burden evaluation by ddPCR might identify patients in need of a closer clinical follow-up during the "watch and wait" interval and after standard chemotherapy.

• 出版日期2016-12-27