Clinical and laboratory characteristics of two acute lymphoblastic leukemia patients with dicentric (9; 20) (p11 - 13; q11) / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the morphologic, immunophenotypic, cytogenetic and clinical features of acute lymphoblastic leukemia (ALL) patients with dicentric (9; 20) (p11 - 13; q11).</p><p><b>METHODS</b>Chromosome specimens of bone marrow cells were prepared by direct method and/or short-time culture. Karyo-typing was performed by R-banding technique. Dual-color fluorescence in situ hybridization (FISH) was performed using both chromosome 9 classical satellite probe and chromosome 20 alpha-satellite probe in one patient.</p><p><b>RESULTS</b>The two ALL patients were positive for CD10 and HLA-DR, showing of B cell origin. Both patients had dicentric (9; 20): case 1 was 45, XY, der (9) t (9; 20) (p11; q11), -20[20]; case 2 was 45, XX, der (9) t (9; 20) (p13; q11), t (9; 22) (q34; q11), -20[10]/46, idem, +8[16]/47, idem, +8, +21[14]. Mutual translocation between chromosomes 9 and 20 of the dicentric chromosome was confirmed by FISH in one patient.</p><p><b>CONCLUSIONS</b>Dicentric (9; 20) (p11 - 13; q11) is a rare recurring chromosome abnormality associated with ALL. Because of the subtle nature of the translocation, FISH is essential for the detection of this abnormality.</p>

Spectrum of gene expression of a multi-drug resistant leukemia cell line with high tumorigenicity in nude mice / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the mechanism of multi-drug resistance of K562-n/VCR cell line with both bcr-abl and mdr-1 expressions by clustering analysis of differential gene expression profiles.</p><p><b>METHODS</b>By DNA microarray technique, genes differentially expressed by K562-n/VCR and K562-n cell lines were identified and analyzed.</p><p><b>RESULTS</b>DNA microarray analysis of K562-n/VCR and K562-n cells was repeated three times and revealed 58 genes significantly differentially expressed among 12,800 genes arrayed. All but one was up-regulated in K562-n/VCR cells. The only gene down-regulated was a-myb. The up-regulated genes were MDR-associated genes, oncogenes, cytoskeleton, protein kinases and phosphatases, apoptotic and antiapoptotic factors, metabolism, transcriptional regulators associated with stress response, cell cycle checkpoint control, and genes for signal transduction proteins.</p><p><b>CONCLUSION</b>These results indicate that, besides MDR-associated genes, other known and unknown genes may also be involved in the mechanism of multi-drug resistance.</p>

Synergistic inhibitory effect of STI571 in combination with arsenic trioxide on a multidrug-resistant leukemia cell line expressing bcr-abl / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the synergistic effect of STI571, an inhibitor of tyrosine kinase in combination with arsenic trioxide (As(2)O(3)) on a multidrug-resistant leukemia cell line expressing bcr-abl.</p><p><b>METHODS</b>The cytotoxic effect of STI571 alone or in combination with different concentrations of As(2)O(3) on both bcr-abl and mdr1 positive leukemia cell line K562-n/VCR was detected by MTT method.</p><p><b>RESULTS</b>The cytotoxic effect of STI571 (1 micromol/L) combined with As(2)O(3) at concentrations 10(-5), 10(-6), 10(-7), 10(-8) mol/L (IC(50) 0.155 micromol/L) on K562-n/VCR cells was significantly higher than that of As(2)O(3) alone (IC(50) 1.879 micromol/L). The synergistic interaction on K562-n/VCR cells increased the cytotoxic effect by 12.1-fold.</p><p><b>CONCLUSION</b>Combination of STI571 with As(2)O(3) has a synergistic inhibiting effect on leukemia cells expressing bcr-abl and mdr1.</p>

The reverse effect on drug-resistance against tyrosine kinase inhibitor STI571 in mdr1 and bcr-abl positive leukemic cells / 中国实验血液学杂志

To explore the possibility of leukemia cell line of both bcr-abl and mdr-1 positive were cross-resistant to tyrosine kinase inhibitor STI571 and its reversal way, the inhibitory effect of STI571 on K562-n/VCR cells was detected with MTT method and reverse effects of CsA, TAM, IFN-alpha and CsA cominated with IFN-alpha were observed. The results showed that K562-n/VCR cell line expressing bcr-abl and mdr1 positive was resistant to STI571, and could be reversed by 5.18, 1.82 and 1.67-fold respectively, when treated with CsA, TAM, and IFN-alpha. It could be reversed by 34.87-fold with combination of half-dose CsA and IFN-alpha. In conclusion, amplification of mdr1 gene may contribute to drug-resistance of bcr-abl positive leukemic cells against STI571. The reversal agents, CsA, TAM and IFN-alpha show obviously reverse effects on drug-resistance. The combination of half-dose of both CsA and IFN-alpha display stronger effect than the full dose of either.

Study on Relation of Early Immune Reconstitution with Acute Graft-Versus-Host Disease / 中国实验血液学杂志

To analyze the relation of early immune reconstitution with acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation (all-HSCT), the changes of CD3(+), CD4(+), CD8(+), CD25(+) and CD69(+) cells in peripheral blood from 26 patients with hematologic malignancies were assayed by flow cytometry within 2 months after allo-HSCT. All patients achieved hematopoietic reconstitution, and grade I and II - IV GVHD were developed in 9 and 5 patients, respectively. CD25(+) cells were increased in patients aGVHD at week 2 after transplantation and the peak value was appeared at week 3. The increase of CD25(+) cells was preceded the occurence of clinical signs of aGVHD. The maximal levels of CD25(+) cells increase correlated significantly with the severity of aGVHD. The increase of CD25(+) cells was declined along with remission of aGVHD signs. Our results suggest that analyzing immune reconstitution after allo-HSCT could predict occurence of aGVHD, and CD25(+) cell increase prior occurence of aGVHD is predictive marker for aGVHD.