[Additional karyotypic abnormalities analysis in patients with hematological malignancies post-allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To analyze the karyotype stability in hematological malignancies patients before and after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and its prognostic significance of monitoring. METHODS: The karyotypes and clinical data of 21 patients with hematological malignancies at the initial diagnosis and at relapse after allo-HSCT were retrospectively reviewed. Chromosome analysis was performed by standard 24 h-cultured method and R banding. RESULTS: Karyotypes at the initial diagnosis and at relapse after allo-HSCT were different in 11 patients (52.38%), including chromosome 1, 3, 6, 12, 17, 21. Numberical abnormalities and structural chromosomal abnormalities always occurs together. The median survival time of relapse of the patients with karyotype changes was significantly shorter than that of patients without a karyotype change (79 d vs 522 d, P = 0.027), and that of the patients with trisomy 6 was also significantly shorter than that of the patients without trisomy 6 (9 d vs 275 d, P = 0.005). CONCLUSION: Karyotype changes after relapse are associated with the prognosis of allo-HSCT.

[Study on the inhibitory effect of RNA interference on replication of dengue virus].

To investigate the inhibitory effect of RNA interference (RNAi) on dengue virus I (DENV-1) replication. Small interfering RNA (siRNA) against the PreM gene of dengue virus was synthesized and transfected into C6/36 cells with liposome, which was then attacked by DENV-1 virus. The antiviral effect of siRNA was evaluated by cytopathic effect (CPE), the cell survival rate measured by MTT, and virus RNA quantified by real-time RT-PCR. The results showed that after 7 days post infection of dengue virus, the transfected C6/36 cells showed less CPE. The cell survival rate of the transfected C6/36 cells increased by 2.26 fold, and the amount of virus RNA in the transfected cells was reduced by about 97.54% as well. These findings indicated that the siRNA could effectively inhibit dengue virus RNA replication, and protect C6/36 cells from viral attack, indicating its potential role in prevention and treatment of dengue fever.

Inhibitory effect of small interfering RNA on dengue virus replication in mosquito cells.

BACKGROUND: Dengue viruses (DENs) are the wildest transmitted mosquito-borne pathogens throughout tropical and sub-tropical regions worldwide. Infection with DENs can cause severe flu-like illness and potentially fatal hemorrhagic fever. Although RNA interference triggered by long-length dsRNA was considered a potent antiviral pathway in the mosquito, only limited studies of the value of small interfering RNA (siRNA) have been conducted. RESULTS: A 21 nt siRNA targeting the membrane glycoprotein precursor gene of DEN-1 was synthesized and transfected into mosquito C6/36 cells followed by challenge with DEN. The stability of the siRNA in cells was monitored by flow cytometry. The antiviral effect of siRNA was evaluated by measurement of cell survival rate using the MTT method and viral RNA was quantitated with real-time RT-PCR. The presence of cells containing siRNA at 0.25, 1, 3, 5, 7 days after transfection were 66.0%, 52.1%, 32.0%, 13.5% and 8.9%, respectively. After 7 days incubation with DEN, there was reduced cytopathic effect, increased cell survival rate (76.9 ± 4.5% vs 23.6 ± 14.6%) and reduced viral RNA copies (Ct value 19.91 ± 0.63 vs 14.56 ± 0.39) detected in transfected C6/36 cells. CONCLUSIONS: Our data showed that synthetic siRNA against the DEN-1 membrane glycoprotein precursor gene effectively inhibited DEN-1 viral RNA replication and increased C6/36 cell survival rate. siRNA may offer a potential new strategy for prevention and treatment of DEN infection.