Detection and quantification of aberrant leukemia fusion gene by real-time RT-PCR / 中国实验血液学杂志

This study was purposed to set up real-time quantitative RT-PCR technique and to measure leukemia fusion gene transcripts in patients with chronic myeloid leukemia (CML), acute lymphoblastic leukemia (ALL) and acute promyelocytic leukemia (APL). All plasmids containing the target gene sequences were constructed to establish the standard curves. A TaqMan based real-time quantitative RT-PCR was performed to measure aberrant fusion gene transcripts in 130 samples of peripheral blood (PB) or bone marrow (BM) from 49 patients with leukemia. The results showd that the BCR-ABL(P210) transcripts were detected in 28 (82.4%) out of 34 CML patients (the ratios of BCR-ABL(P210)/ABL varied from 0.01 to 3.19) and also in 2 (33.3%) out of 6 ALL patients. The BCR-ABL(P190) transcripts were detected in 2 (33.3%) out of 6 ALL patients. The BCR-ABL(P210) and BCR-ABL(P190) transcripts were both detected in 1 (2.9%) CML patients. The PML/RARalpha transcripts were detected in 7 (77.8%) out of 9 APL patients (the ratio of PML-RARa/ABL varied from 0.0014 to 3.199). The relative frequency of both bcr1 and bcr3 was 42.9%, while that of bcr2 was 14.3%. The transcript level of aberrant fusion gene varied from the clinical situation of patient. It is concluded that real-time quantitative PCR is a reliable, innovative and promising technology with high sensitivity and specialty. It has potential clinical value for defining diagnosis, typing tumor, selecting treatment, measuring the tumor load, monitoring fusion gene expression level and evaluating therapeutic strategies, which is worthy to be popularized.

Apoptosis and cell cycle arrest in lymphoma Raji cells induced by arsenic trioxide / 中国实验血液学杂志

This study was aimed to investigate the apoptosis induced by arsenic trioxide (As2O3) in lymphoma Raji cells and its possible mechanisms. The inhibitory effect of different concentration of As2O3 on cell proliferation was tested by MTT assay. Apoptosis was observed with electron microscope and DNA electrophoresis. The distribution of cell cycles and cell apoptosis were detected by flow cytometry. The results showed that the 1-8 micromol/L As2O3 inhibited Raji cell growth effectively in a dose-and time-dependent manner. As2O3 at 2-8 micromol/L could induce the cell apoptosis and cell cycle arrest. However, As2O3 at 1 micromol/L inhibited Raji cells proliferation only by cell cycle arrest, without any signs of cell apoptosis. In conclusion, substantial proliferation inhibition, cell cycle arrest and apoptosis in Raji cells could be induced by As2O3. Cell cycle arrest happens with apoptosis, when treated with As2O3.

Inhibited proliferation of B-lymphoma Raji cells and down-regulated expression of VEGF by arsenic trioxide / 中国实验血液学杂志

This study was aimed to investigate the effects of As2O3 on proliferation of B lymphoma Raji cell and to study the expression changes of VEGF mRNA. The modified MTT was adopted to evaluate the effect of As2O3 on proliferation of Raji cells. Semi-quantitative RT-PCR was used to detect the expression of VEGF121 and VEGF165 mRNA in Raji cells exposed to As2O3. The results showed that the As2O3 significantly inhibited the proliferation of Raji cells, the relationship between the inhibition rate and the concentrations of As2O3 was dose- and time-dependent. The VEGF121 and VEGF165 mRNA expressions were found in Raji cells, and both were well-matched in expression levels. After treatment of As2O3 at 1 micromol/L for 48 hours, the expression levels of VEGF121 and VEGF165 mRNA were significantly down-regulated and demonstrated negative correlation with the time of exposure to As2O3. Otherwise some difference were observed in effects of As2O3 on VEGF121 and VEGF165, the expression of VEGF165 mRNA was down-regulated earlier and longer than that of VEGF121, while no similar correlation was found in selected concentration groups. It is concluded that As2O3 can significantly inhibit the growth of Raji cells and may exerted its anti-angiogenesis effects by down-regulating the VEGF mRNA expression even in a low concentration for a long term.