RNAi-mediated Silencing of CXCR4 Inhibits the Adhesion, Invasion and Tumorigenicity of Acute Monocytic Leukemic Cell Line SHI-1 / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of CXCR4 gene on the proliferation, adhesion, invasion and tumorigenicity of a human monocytic leukemic cell line SHI-1.</p><p><b>METHODS</b>The lentivirus vector silencing the expression of CXCR4 was constructed for infection of SHI-1 cells silencing expression of CXCR4 in SHI-1 cells. The expression of CXCR4, MMP-2 and MMP-9 was detected by real time PCR. The expression of CXCR4 on membrane of SHI-1 cells was detected by flow cytometry. The SHI-1 cell proliferation ability was detected by MTT. The co-culture system of the leukemia cells and bone marrow stromal cells was used to detect the adhesion and migration ability of leukemia cells. SHI-1 cells were inoculated subcutaneously in nude mice to investigate the growth ability in vivo.</p><p><b>RESULTS</b>After SHI-1 cells were infected by lentivirus silencing expression of CXCR4, the expression of CXCR4 mRNA in SHI-1 CXCR-4i cells decreased by 76% as compared with expression of SHI-1/NC of negative control virus, the expression of CXCR4 on membrane of SHI-1/CXCR4i obviously downregulated; the expression of MMP-2 and MMP-9 in SHI-1/CXCRi cells also declined by 63% and 62% respectively; the proliferation ability of SHI-1/CXCR4i in vitro did not obviously changed, but the adhesion and trans-matrigel invasion ability significantly decreased, the SHI-1/CXCR4i cells could not form neoplasm subcutaneously in mice, but the SHI-1 and SHI-1/NC cells could form neoplasm subcutaneously in mice, and there was no significant difference in volumn of neoplasm mass.</p><p><b>CONCLUSION</b>The silencing expression of CXCR4 can decline the adhesion and migration ability of SHI-1 cells, and can completely suppress the formation of neoplasm subcutaneously, so the CXCR4 may serve as a target for treating leukemia.</p>

Deletions and rearrangements of PAX5 gene in B-lineage acute lymphoblastic leukemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the frequency paired-box domain 5 (PAX5) gene alterations in B-lineage acute lymphoblastic leukemia (B-ALL) harboring 9p abnormalities and its implication for clinical prognosis.</p><p><b>METHODS</b>Bacterial artificial chromosomes RP11-344B23 and RP11-652D9 encompassing the PAX5 gene were selected. DNA was extracted with conventional method and labeled with fluorescein by nicking transition. Fluorescence in situ hybridization (FISH) was used to determine the rearrangement or deletion of the PAX5 gene in B-ALL harboring chromosome 9p abnormalities. Clinical and laboratory features of patients were analyzed.</p><p><b>RESULTS</b>Fifty cases were analyzed with FISH. Complete deletion was observed in 23 patients (46%), partial deletion was observed in 2 patients (4%), and rearrangement was detected only in 1 case. The total frequency of abnormalities was 52% (26/50). No significant difference was found in clinical features of patients with or without PAX5 rearrangement or deletion.</p><p><b>CONCLUSION</b>The frequency of PAX5 gene alterations in B-ALL harboring 9p abnormalities was 52%. However, no significant difference was found between patients with and without PAX5 alterations.</p>

A clinical and laboratory study of TCF3-PBX1 positive adult acute lymphoblastic leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the morphology, immunophenotype, cytogenetics and clinical features of TCF3-PBX1 fusion gene positive adult acute lymphoblastic leukemia (ALL).</p><p><b>METHODS</b>R banding was used to analyze conventional cytogenetics (CC), interphase fluorescence in situ hybridization (iFISH) and RT-PCR to detect the TCF3-PBX1 fusion gene, and flow cytometry to immunophenotype. The clinical and laboratory features and long-term follow-up of the patients were analyzed.</p><p><b>RESULTS</b>The incidence of 19 TCF3-PBX1-positive adult ALL was 3.13% of total ALL patients. Of them, 12 and 7 cases were diagnosed as L(1) and L(2) morphology respectively; 7 cases with balanced translocation of chromosome 1 and 19; 10 with der(19) t(1;19) formed from unbalanced translocation and 2 with normal karyotypes. TCF3-PBX1 fusion gene was detected by RT-PCR in 9 cases, and by iFISH in 17. 16 cases were B-phenotype and the other 2 T-phenotype; 17 cases had lymph node, spleen or liver infiltration. Of 18 patients received chemotherapy, 17 (94.7%) achieved complete remission (CR); the median relapse-free survival (RFS) and median overall survival was 3.2 months and 7.2 months, respectively.</p><p><b>CONCLUSIONS</b>TCF3-PBX1-positive adult ALL had unique clinical and pathological features with high remission rate, high relapse rate and short survival time and should be considered to receive intensified treatment strategies. iFISH combined with CC and RT-PCR can increase the detection rate of t(1;19)/TCF3-PBX1 fusion gene.</p>