Mutation of IL-7R in Adult Patients with T-cell Acute Lymphoblastic Leukemia and Its Clinical Significance / 中国实验血液学杂志

<p><b>OBJECTIVE</b>Interleukin 7 (IL-7) and its receptor（IL-7R）are essential for normal T-cell development and homeostasis. This study was aimed to investigate the IL-7R mutation and its clinical significance in adult patients with adult acute lymphoblastic leukemia (ALL), particularly in T-ALL.</p><p><b>METHODS</b>The exons of IL-7R were amplified, cloned and sequenced in 144 adult patients with ALL; the frequency, position and lypes of IL-7R mutation were detected and their correlation with clinical features was analyzed.</p><p><b>RESULTS</b>7.3% of T-ALL and 1.1% of B-ALL showed somatic IL-7R mutations which located at exon 6 and exon 5, respectively. Moreover, the IL-7R mutation was associated with poor clinical outcome in adult ALL patients. Furthermore, the co-existence of IL-7R mutation with NOTCH1 mutations and/or PHF6 mutation in T-ALL was observed.</p><p><b>CONCLUSION</b>IL-7R mulation and its associated signaling pathways may play an important role in the pathogenesis of T-ALL.</p>

Characterization of HKI-272 covalent binding to human serum albumin.

The study was initiated as an observation of incomplete extraction recovery of N-(4-(3-chloro-4-(2-pyridinylmethoxy)anilino)-3-cyano-7-ethoxy-6-quinolyl)-4-(dimethylamino)-2-butenamide (HKI-272) from human plasma. The objective of this study was to 1) identify the binding site(s) of HKI-272 to human plasma protein(s); 2) characterize the nature of the binding; and 3) evaluate the potential reversibility of the covalent binding. After incubation of [(14)C]HKI-272 with human plasma, the mixture was directly injected on liquid chromatography/mass spectrometry (LC/MS), and an intact molecular mass of HKI-272 human serum albumin (HSA) adduct was determined to be 66,999 Da, which is 556 Da (molecular mass of HKI-272) larger than the measured molecular mass of HSA (66,443 Da). For peptide mapping, the incubation mixture was separated with SDS-polyacrylamide gel electrophoresis followed by tryptic digestion combined with LC/tandem MS. A radioactive peptide fragment, LDELRDEGKASSAK [amino acid (AA) residue 182-195 of albumin], was confirmed to covalently bind to HKI-272. In addition, after HCl hydrolysis, a radioactive HKI-272-lysine adduct was identified by LC/MS. After combining the results of tryptic digestion and HCl hydrolysis, the AA residue of Lys190 of HSA was confirmed to covalently bind to HKI-272. A standard HKI-272-lysine was synthesized and characterized by NMR. The data showed that the adduct was formed via Michael addition with the epsilon-amine of lysine attacking to the beta-carbon of the amide moiety of HKI-272. Furthermore, reversibility of the covalent binding of HKI-272 to HSA was shown when a gradual release of HKI-272 was observed from protein pellet of HKI-272-treated human plasma after resuspension in phosphate buffer, pH 7.4, at 37 degrees C for 18 h.