SiRNA targeting ICP4 attenuates HSV-1 replication / 病毒学报

HSV-1, a neurotropic virus, always leads to severe nervous symptoms. It is hard to completely eradicate the latent viruses after conventional therapy so that recurrence is inevitable. ICP is a key regulator for HSV replication and transcription that determines the cytolytic infection or latent state. In search of new anti-virus strategy targeting HSV-1ICP4, two pairs of siRNA were designed, and a recombinant eukaryotic lentiviral expression plasmid pLKO-puro(r)-hU6-siRNA was constructed. Vero cells were transfected with the designed siRNAs by Lipofectamine 2000 and four stable monoclonal cell lines were established by puromycin screening method. The ICP4 expression at mRNA level was detected with real-time PCR, and the HSV-1 replication was measured with TCID50 assay. SiRNA was shown as an effective way to inhibit the expression of ICP4 in monoclonal cell lines. Meanwhile, HSV-1 replication was significantly inhibited when ICP4 was shut down by siRNA. We conclude that siRNA targeting ICP4 attenuates HSV-1 replication. Further more, multi-site siRNAs show stronger inhibitory effect on viral replication, which may be an effective and feasible approach for biological anti-viral drugs.

Analysis of Flt-3 expression and Flt-3/ITD mutation in acute myeloid leukemia cells / 中国实验血液学杂志

This study was aimed to explore the relationship between Flt-3 expression, Flt-3/ITD mutation in acute leukemia (AL) cell line and pathogenesis of AL, especially AML. The Flt-3 expression and Flt-3/ITD mutation were detected by RT-PCR and sequencing method in 82 leukemia cell lines including 20 AML, 57 ALL and 5 CML cell lines. The results indicated that positive results of Flt-3 expression were obtained in 48 out of 77 AL cell line, the positive rate was 62%; 12 cell lines were positive in 20 AML cell lines, the positive rate was 60%; 33 cell lines was positive in 57 ALL cell lines, the positive rate was 58%; 3 cell lines were positive in 5 CML cell lines, the positive rate was 60%. There was abnormal gene product in 1 AMOL cell line out of 12 AML cell lines with Flt-3 positive expression (positive rate 8.3%). DNA sequencing of abnormal gene product showed two coding duplication sequence with 29 bp long. The positive rate of Flt-3 expression in undifferentiated cell line was prominently higher than that in mature B cell ALL (P < 0.05). It is concluded that the Flt-3 expression is different in various leukemia cells. Flt-3/ITD duplication was found in one AML cell line. The detection of Flt-3 gene and Flt-3/ITD mutation may contribute to the diagnosis of ALL, especially to AML.

Analysis of DEK-CAN fusion gene expression in acute myeloid leukemia patients with 6; 9 chromosome translocation / 中国实验血液学杂志

This study was aimed to explore the relationship of 6; 9 chromosome translocation with DEK-CAN fusion gene expression in patients with acute myeloid leukemia (AML) and its clinical significance. Chromosome specimens were prepared by routine method after short-term culture of bone marrow cells; karyotype analysis was performed by R banding technique; the expression of fusion gene DEK-CAN was analyzed by RT-nested-PCR in mononuclear cells of bone marrow or peripheral blood of 4 AML patients, for 3 patients received allo-BMT out of 4 patients the dynamic follow-up was performed. The results indicated that t (6; 9) (p23; q34) was confirmed by chromosome karyotype analysis in the four AML patients. The DEK-CAN fusion gene was found during in all four de novo, relapsed and CR patients (100%). And the expression of DEK-CAN fusion gene enhanced apparently in de novo and relapsed patients, and weakened in CR patient. DEK-CAN mRNA was found in the three patients during 1-24 months after allo-BMT. Clinical data showed 2 patients relapsed and died after CR for 1-24 months; the other two patients received allo-BMT got CR and still survive. It is concluded that DEK-CAN fusion gene is the molecular basis in pathogenesis of AML. The detection of DEK-CAN fusion gene is significant for diagnosis of AML, evaluation of curative effect, and predication of prognosis.