Cytogenetic characteristics of 163 children with acute lymphoblastic leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To further understand the cytogenetic characteristics of pediatric acute lymphoblastic leukemia (ALL).</p><p><b>METHODS</b>Cytogenetic abnormalities of 163 children with newly diagnosed ALL (0-17 years of age) were evaluated by conventional cytogenetic analysis and fluorescent in situ hybridization findings.</p><p><b>RESULTS</b>Chromosome abnormalities were detected in 87.7% of patients (143/163). The ploidy levels most frequently observed among ALL patients were high hyperdiploidy (51-67 chromosomes) (45 cases, 27.6%), Chromosomes X and 21 were gained in 100% of these cases. The most common genetic alterations were t(12;21)/ETV6/RUNX1 (26 cases, 16.0%), followed by t(1;19)/TCF3/PBX1 (13 patients, 8.0%), t(4;11)/MLL rearrangement and t(8;14) IGH/MYC (6 cases, 3.7%), t(9;22)/BCR/ABL(2 cases, 1.2%), and iAMP21 (1 patient, 0.6%). The no-classical structural abnormalities included dup(1q) in 20.2%, del(6q) and del(9p) in 10.4%, del(12p) in 12.9% and del(13q) in 5.5%. The incidences of t(12;21), t(1;19), t(9;22) and high hyperdiploidy were consistent with reports in Western children (P>0.25). The incidence of (9;22) seemed to be much lower in our study than that in Korea (1.5% vs 9.5%, P<0.005).</p><p><b>CONCLUSION</b>Cytogenetic findings of childhood ALL patients are similar to that of Western countries, it seems no more adverse risk factors.</p>

Knockdown of proteasome subunit α7 with small interfering RNA inhibits cell proliferation of K562 cell line / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the effect of human proteasome subunit Α7(PSMA7)gene silencing by small interfering RNA(siRNA)on human myeloid leukemia cell line K562.</p><p><b>METHODS</b>PSMA7 gene-specific siRNA was chemically synthesized and transfected into K562 cell line by HiPerFect. The expression level of PSMA7 protein was detected by Western blot analysis. Cell proliferation was determined by MTS and cell counting. Cell cycle distribution was measured by flow cytometry. The expressions of Cyclin A, D, and E were detected by Western blot analysis. The apoptotic ratio was determined by flow cytometry.</p><p><b>RESULTS</b>PSMA7 protein was evidently silenced 48 hours after transfection of the PSMA7-specific siRNA into K562 cell line. The proliferation of the cells was markedly inhibited, and the percentage of S phase cells decreased. However, no apoptosis was observed. The expressions of Cyclin A and E were down-regulated.</p><p><b>CONCLUSION</b>Knockdown of PSMA7 down-regulates the expression of Cyclin A and E and thus decreases the proportion of cells in S phase as a result, the proliferation of K562 cell line is inhibited.</p>