ABSTRACT
BACKGROUND: Currently the hematopoietic stem cells can be obtained from bone marrow, peripheral blood and cord blood, so it is expected to search a new source of stem cells in order to satisfy the clinical transplantation needs. From the 5th week of pregnancy, the blood sinusoid system develops completely in liver, and then hematopoietic stem cells can move with blood flow. OBJECTIVE: To observe the biological features of human fetal blood hematopoietic stem/progenitor cells (HS/PCs), and their transplantation into non-obese diabetic/severe combined immunodeficiency disease (NOD/ SCID) mice. DESIGN: Control trial. SETTING: Department of Hematology, First Affiliated Hospital of Guangxi Medical University. MATERIALS:①Cell resource: Twenty-one fetal blood samples were from dead fetus [gestational age of 18-29 weeks, mean (24.2±3.2) weeks] and twenty-one full-term cord blood samples were provided from the Department of Obstetrics, First Affiliated Hospital of Guangxi Medical University between October 2002 and February 2003, with the consent of their relatives.②Experimental animal: Twelve NOD/SCID female mice of 6-7 weeks old were bred in sterility and super-clean operation board. METHODS: Flow cytometer was used to assess cell surface markers of HS/PCs including CD34, CD38, HLA-DR and CD90 in 21 human fetal blood samples, and their expressions were compared with 21 human cord blood samples. Moreover, human fetal blood mononuclear cells (MNCs) were transplanted into 6 NOD/SCID mice irradiated sublethally. After 5 weeks, human leukocytic content was also detected in bone marrow of mice with flow cytometer while human Cart-1 gene in recipients' bone marrow was sensed with polymerase chain reaction (PCR).MAIN OUTCOME MEASURES: ① Expressions of HS/PCs surface markers in fetal blood and cord blood. ②Implantation of fetal blood cells into NOD/SCID mice.RESULTS: ①The percentage of CD34+ cells in fetal blood was significantly higher than that of full-term cord blood [(2.258 8±0.720 9)%,(1.572 9±0.478 3)%, P=0.000 4]. The percentages of CD34+CD38- cells and CD34+CD90+ cells in fetal blood were also higher than those of fullterm cord blood [(1.298 6±0.470 6)%, (0.871 0±0.409 5)%, P=0.001 6;(0.930 0±0.469 2)%, (0.560 0±0.365 8)%, P=0.032 4].②Four cases (4/6)of human fetal blood MNCs smoothly transplanted the hematopoiesis of sublethally irradiated NOD/SCID mice. Five weeks after the transplantation, human leukocyte and Cart-1 gene could still be detected in marrow cells of NOD/SCID mice.CONCLUSION: Human fetal blood contains more HS/PCs than cord blood. Human fetal blood MNCs can engraft bone marrow of NOD/SCID mice and reconstitute general hemopoiesis of marrow and lymph systems.Human fetal blood is a new possible source of pluripotential hematopoietic stem cell.
ABSTRACT
In order to investigate the relationship between the expression of cyclin A and drug resistance in adult patients with acute leukemia (AL), the mRNA expression of cyclin A, mdr1, Top II alpha, bcl-2 was detected in 64 adult patients with AL and 20 normal controls by semi-reverse transcription polymerase chain reaction (semi-RT-PCR). It was found that the cyclin A and Top II alpha mRNA expression levels in drug resistant group were significantly lower than in sensitive group (P < 0.01). Under the same experimental condition no cyclin A mRNA expression was detectable in all normal controls. The mdr1 and bcl-2 mRNA expression levels in resistant group were significantly higher than in sensitive group (P < 0.01), cyclin A and Top II alpha gene expression levels were closely correlated (rs = +0.794, P = 0.000, n = 64) in all AL patients, but cyclin A was not correlated with mdr1 and bcl-2 gene expression levels. In drug resistant group there was a negative correlation between the gene expression levels of cyclin A and mdr1 (rs = -0.337, P = 0.029). The 10 AL patients with positive lower expression of both cyclin A and Top II alpha were all resistant to drugs. Logistic regression of Binary analysis showed the correlation between the lower expression of cyclin A and drug resistance. It was concluded that lower expression of cyclin A gene might be an unfavorable prognostic factor for patients with AL, and detection of both cyclin A and Top II alpha gene expression would predict drug resistance in AL patients.
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , ATP Binding Cassette Transporter, Subfamily B, Member 1 , Genetics , Cyclin A , Genetics , Drug Resistance, Multiple , Genetics , Drug Resistance, Neoplasm , Genetics , Genes, MDR , Genetics , Leukemia, Myeloid, Acute , Genetics , Leukemia, Promyelocytic, Acute , Genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Genetics , RNA, Messenger , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To investigate the relationship between the expression of cyclin A and drug resistance in patients with adult acute leukemias.</p><p><b>METHODS</b>The mRNA expressions of cyclin A, mdr1, Topo II alpha and bcl-2 were measured in 64 patients with adult acute leukemia (AL) and 20 normal subjects by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>(1) The cyclin A and Topo II alpha mRNA expression levels in the treatment resistant group were significantly lower than that in the sensitive group (P < 0.01). There was no cyclin A mRNA expression in the 20 normal subjects under the same experiment condition. (2) The mdr1 and bcl-2 mRNA expression levels in the resistant group were significantly higher than that in sensitive group (P < 0.01). (3) Cyclin A and Topo II alpha gene expression levels were positively correlated (r = 0.794, P = 0.000) in the 64 AL patients, and there was a negative correlation between the gene expression levels of cyclin A and mdr1 (r = -0.337, P = 0.029) in the drug resistant group. (4) Ten AL patients with low expressions of both cyclin A and Topo II alpha were all in the resistant group. Logistic regression of binary analysis showed a significant correlation between the low expression of cyclin A and drug resistance.</p><p><b>CONCLUSION</b>Low expression of cyclin A gene might be a unfavorable prognostic factor for patients with AL and measurement of both cyclin A and Topo II alpha gene expression would predict drug resistance for AL patients.</p>