儿童急性T淋巴细胞白血病T细胞受体β链基因重排的特点及其在微小残留病定量检测中的意义

Objective To explore the characteristics of T-cell receptor beta (TCRβ) gene rearrangement in children with T-cell acute lymphoblastic leukemia (T-ALL) and establish a system for quantitative detection of minimal residual disease (MRD) by real-time quantitative PCR (RQ-PCR) targeting the TCRβ gene rearrangement. Methods Multiplex PCR designed by the BIOMED-2 was used to detect TCRβ gene rearrangement in the bone marrow samples of 26 children with T-ALL. Sequences of junctional region were then compared and analyzed in IMGT database. Allele specific oligonucleotide (ASO) upstream primers were designed complementary to the V-D-J or D-J junctional region of TCRβ gene rearrangements. Samples at diagnosis were serially diluted in DNA obtained from mononuclear cells (MNC) from a pool of 20 healthy donors to generate the patient-specific standard curves. Subsequently, TCRβ RQ-PCR was applied to six patients to quantify MRD with germline Jβ primer/probe combinations. To determine the quantity and quality of DNA, we also used RQ-PCR for the N-ras gene.Results Clonal rearrangements were identified in 92.3% of the children with T-ALL ( Vβ-Dβ-Jβ rearrangements in 84.6% and Dβ-Jβ rearrangements in 50% ). Comparative sequence analysis of 42 TCRβ recombination revealed that two downstream Vβ families (BV5, BV6) were preferentially used. The segment Jβ2. 7 was dominant in childhood T-ALL. Jβ1. 3, Jβ2.4, and Jβ2.6 were not detected. The slope of the standard curves was from - 3.54 to -3.37 with the intercepts between 19.35 and 20.51. The correlation coefficients of all the 6 standard curves were ≥0.98. None of the cases had a quantitative range of RQ-PCR lower than 10<'-4>. During the follow-up, an increased incidence of MRD was found before relapse.Conclusions RQ-PCR, which is a highly sensitive and specific method for detection of TCRβ gene rearrangements, will be of high value to study MRD in T-ALL. Close monitoring of MRD is of great importance for prognosis and follow-up of the patients with the disease.

维生素K3对HL-60细胞凋亡的诱导作用

目的: 观察维生素K3(VK3)对HL-60细胞凋亡的诱导作用.方法: 通过形态学、DNA 电泳、Annexin V标记法检测VK3作用后HL-60细胞的凋亡发生情况.结果:2、 5、 10、 20 μmol/L的VK3作用于HL-60细胞48 h后凋亡发生率分别为8.76%、 9.7%、 18.54%、 75.4%; 10 μmol/L的VK3作用于HL-60细胞24、 48、 72、 96 h后凋亡发生率分别为11.35%、 18.54%、 21.22%、 37.54%.结论: VK3能诱导HL-60细胞发生凋亡, 并具有一定的量效和时效关系.

We developed phase-switch microfluidic devices for molecular profiling of a large number of single cells. Whole genome microarrays and RNA-sequencing are commonly used to determine the expression levels of genes in cell lysates (a physical mix of millions of cells) for inferring gene functions. However, cellular heterogeneity becomes an inherent noise in the measurement of gene expression. The unique molecular characteristics of individual cells, as well as the temporal and quantitative information of gene expression in cells, are lost when averaged among all cells in cell lysates. Our single-cell technology overcomes this limitation and enables us to obtain a large number of single-cell transcriptomes from a population of cells. A collection of single-cell molecular profiles allows us to study carcinogenesis from an evolutionary perspective by treating cancer as a diverse population of cells with abnormal molecular characteristics. Because a cancer cellpopulation contains cells at various stages of development toward drug resistance, clustering similar single-cell molecular profiles could reveal how drug-resistant sub-clones evolve during cancer treatment. Here, we discuss how single-celltranscriptome analysis technology could enable the study of carcinogenesis from an evolutionary perspective and the development of drug-resistance in leukemia. The single-cell transcriptome analysis reported here could have a direct and significant impact on current cancer treatments and future personalized cancer therapies.

Sudden Death due to Brainstem Leukemic Hemorrhage:A Case Report

IntroductionLeukem ia is a hem atologic neoplasm characterized by potential infectious and hem orrhagic com plications In adult patients with acute leukem ia,in fection is the most com m on com plication.Imtrcra nial hem orrhage (ICH) is the second most common com plication.H ow ever,ICH has been identified as the m ajor cause of m orbidity and m ortaliity in pa tients with leukem ia[1-6].A num ber of case ceports ascribed the death of leukem ic patients due to hem orrhge of the supratentorial and infratentorial brain,basal ganglia,and cerebellum [2,7-9].However,few cases have reported on brainstem hem orrhage.The current case report involved a young wom an who died of brainstem hem orrhage due to acute leukem ia,discussing the pathophysiologic m echanism underly ing ICH.Futhherm ore,the risk factors were specified,w ith a provision of suggestions to forensic pathologists in handling deaths associated w ith ICH,especially sudden unexpected deaths.