Recurrent pulmonary infection and oral mucosal ulcer / 中国当代儿科杂志

An 8-year-old girl who had experienced intermittent cough and fever over a 3 year period, was admitted after experiencing a recurrence for one month. One year ago the patient experienced a recurrent oral mucosal ulcer. Physical examination showed vitiligo in the skin of the upper right back. Routine blood tests and immune function tests performed in other hospitals had shown normal results. Multiple lung CT scans showed pulmonary infection. The patient had recurrent fever and cough and persistent presence of some lesions after anti-infective therapy. The antitubercular therapy was ineffective. Routine blood tests after admission showed agranulocytosis. Gene detection was performed and she was diagnosed with dyskeratosis congenita caused by homozygous mutation in RTEL1. Patients with dyskeratosis congenita with RTEL1 gene mutation tend to develop pulmonary complications. Since RTEL1 gene sequence is highly variable with many mutation sites and patterns and can be inherited via autosomal dominant or recessive inheritance, this disease often has various clinical manifestations, which may lead to missed diagnosis or misdiagnosis. For children with unexplained recurrent pulmonary infection, examinations of the oral cavity, skin, and nails and toes should be taken and routine blood tests should be performed to exclude dyskeratosis congenita. There are no specific therapies for dyskeratosis congenita at present, and when bone marrow failure and pulmonary failure occur, hematopoietic stem cell transplantation and lung transplantation are the only therapies. Androgen and its derivatives are effective in some patients. Drugs targeting the telomere may be promising for patients with dyskeratosis congenita.

Painless skin nodules and ecchymosis in a school-aged girl / 中国当代儿科杂志

A 7-year-old girl was admitted to Xiangya Hospital due to systemic lymphadenectasis for 2 months and skin ecchymosis for 3 days. Nine months ago, the girl experienced painless nodules in the left lower extremity with no apparent causes. Three months later, dermatorrhagia and ecchymosis occurred in many regions such as the periocular areas, conjunctiva, oral mucosa, perineal area, and groin, with a "raccoon sign" in both eyes; superficial lymphadenectasis and hepatosplenomegaly were also observed in many regions. The pathological sections for the skin nodules showed malignant tumors in lymphohematopoietic cells, and in combination with clinical manifestations, immunohistochemistry, and positive results for CD4, CD56, and CD123 by bone marrow flow cytometry, the girl was diagnosed with blastic plasmacytoid dendritic cell neoplasm. Then high-risk ALL regimen was applied as the chemotherapy for this girl. At present, the girl has been followed up for 3 months; ecchymosis has disappeared, and the enlarged lymph nodes have shrunk. No abnormal cells have been found in bone marrow morphological examination, and bone marrow flow cytometry has shown that primitive precursor cells account for 1.5% and express CD33, CD34, CD123, and CD117.

Experimental study of up-regulating PTEN gene on increasing the chemosensitivity in K562/ADM cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the mechanism of decreasing the K562/ADM cells chemosensitivity by up-regulating expression of PTEN gene.</p><p><b>METHODS</b>K562/ADM cells were transient transfected with pGFP-PTEN or vector. The level of PTEN in K562/ADM cells was assayed by Western blot and RT-PCR. Cell viability on K562/ADM was determined by MTT assay. Cell apoptosis by flow cytometry. Activity of caspase-3 by Caspase Colorimetric Assay Kit. The proteins expression of LC3-I/II, Beclin1, p-Akt, p-p70S6K by Western blot. The autophagic vacuoles by MDC stain and Electron microscopy.</p><p><b>RESULTS</b>(1) The mRNA and protein levels of PTEN in K562/ADM cells transfected with pGFP-PTEN were significantly increased compared with the control (untreated and transfected with empty vector). (2) Enhanced expression of PTEN by gene transfection resulted in a reversal of resistance to ADM. Compared with empty vector group, cell viability decreased from (94.07 ± 2.6)% to (53.83 ± 4.2)%, the cell apoptotic rate increased from (11.89 ± 1.7)% to (43.69 ± 2.3)%, meanwhile, pretreated with caspase-3 inhibitor (Z-DEVE-FMK) didn't completely inhibit the cytotoxicity of ADM to K562/ADM cells. (3) After treated with ADM for 12 and 24 h, the activities of caspase-3 in PTEN-transfected K562/ADM cells increased compared with those in pGFP-transfected K562/ADM cells \[(2.27 ± 0.13) vs (1.19 ± 0.14)\] at 12h, \[(3.15 ± 0.08) vs (1.48 ± 0.05)\] at 24 h (P < 0.05). (4) The protein levels of LC3-II and Beclin1 in K562/ADM cells transfected with pGFP-PTEN were increased by 83% and 18% respectively, and the protein levels of p-Akt and p-p70S6K were declined by 96% and 87% respectively, compared with those in K562/ADM cells transfected with pGFP plasmid. (5) The upregulation of PTEN in K562/ADM cells improved the number of autophagic vacuoles compared with the empty vector group.</p><p><b>CONCLUSION</b>The upregulation of PTEN expression increases the chemosensitivity of K562/ADM to ADM, which may related with the inhibition of PI3K/AKT/mTOR pathway induced by PTEN gene transfection.</p>

Interaction of WAVE1 and genes involved in multiple drug resistance in children with acute myeloblastic leukemia / 中华儿科杂志

<p><b>OBJECTIVE</b>Multidrug resistance (MDR) is one of the primary causes of suboptimal outcomes in chemotherapy of children with acute myeloblastic leukemia (AML). The mechanisms of drug transport resistance may chiefly contribute to MDR. Expression and/or activity of P-glycoprotein (P-gp), multiple resistance-associated protein-1 (MRP1), lung-resistance related protein (LRP) and breast cancer resistance protein (BCRP) have been considered to be associated with unfavourable outcomes in pediatric AML patients. In previous studies, we found WASP-family verprolin-homologous protein-1 (WAVE1) was involved in the MDR mechanisms in K562/A02 leukemia cells. To investigate the expression of WAVE1, P-gp, MRP1, LRP/MVP and BCRP; and if WAVE1 is involved in MDR of human leukemia cell.</p><p><b>METHODS</b>WAVE1, P-gp, MRP1, LRP, BCRP mRNA and protein expression in bone marrow mononuclear cells (BMMCs) were measured by real-time fluorescence quantitative PCR (RQ-PCR) and Western blot in a cohort of 52 children with acute myeloblastic leukemia. During follow-up, of the 52 patients, 21 were documented as being relapsing or refractory, and 31 were induced into complete continuous remission. Furthermore, HL60 cells and HL60/ADR cells were transiently transfected with PCDNA3.1-WAVE1 reconstructed plasmid and specifically siRNA to WAVE1 respectively, and the expression of WAVE1, MRP1 and BCRP before and after transfection was assessed by real-time PCR and Western blot analysis.</p><p><b>RESULTS</b>(1) The expression levels of WAVE1, P-gp, MRP, LRP and BCRP in refractory/relapsing group were much higher than that in complete continuous remission (CCR) group. (2) WAVE1 mRNA and protein expression in BMMCs of children were at higher levels when they were newly diagnosed or relapsed, compared with complete continuous remission. (3) The WAVE1 expression at mRNA and protein level in HL60/ADR cells was increased by about 353% and 95% respectively as compared with that in HL60 cells. (4) Overexpression of WAVE1 in HL60 cell lines upregulated the expression levels of MRP and BCRP (MRP mRNA and protein level were increased by about 16.54 times and 129% respectively, BCRP was increased by 4.93 times and 96%); whereas suppression of WAVE1 expression by RNA interference downregulated the expression levels of MRP1 and BCRP (MRP mRNA and protein level was only 11% and 43% of pre-disturbance respectively, BCRP was 14% and 71%).</p><p><b>CONCLUSIONS</b>Higher levels of WAVE1 in the BM indicate an unfavorable prognosis in children with AML. WAVE1 is related to the development of AML and involved in the MDR mechanisms, and regulates the level of MRP1 and BCRP.</p>

Expression of WAVE1 and p22phox in children with acute lymphocytic leukemia and the relationship of WAVE1 with oxidative stress / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the expression of WAVE1 and p22phox in peripheral blood mononuclear cells (PBMCs) in children with acute lymphocytic leukemia (ALL) and the relationship of WAVE1 with oxidative stress.</p><p><b>METHODS</b>Real-time PCR was used for detecting WAVE1 and p22phox expression in PBMCs in 41 children with ALL and 10 normal controls. Plasma activity of superoxide dismutase (SOD) was measured by the xanthine oxidase method. Plasma activity of GSH-Px was measured by the DTNB reaction test.</p><p><b>RESULTS</b>The expression of WAVE1 and p22phox was significantly higher in the active ALL groups (newly diagnosed and relapse ALL) than that in the normal control and the complete remission (CR) ALL groups (<0.01). The CR ALL group showed increased WAVE1 and p22phox expression than those in the normal control group (<0.05). Plasma activities of SOD (22.62+/-7.39 U/mL) and GSH-Px (91.73+/-28.88 micromol/L) in the active ALL group were significantly lower than those in the normal control (166.35+/-27.93 U/mL and 490.94+/-39.38 micromol/L, respectively) and the CR ALL groups (107.11+/-28.57 U/mL and 267.56+/-82.64 micromol/L, respectively) (<0.01). WAVE1 expression was positively correlated with p22phox expression (r=0.34, <0.05) but negatively correlated with plasma activities of SOD and GSH-Px ( r=-0.336 and-0.408, respectively; <0.05).</p><p><b>CONCLUSIONS</b>WAVE1 and p22phox expression in PBMCs increased and was associated with the disease course in children with ALL. Oxidative stress may be involved in the regulation of WAVE1 expression in ALL children.</p>

Role of WAVE1 in K562 leukemia cells invasion and its mechanism / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate role of WASP family verprolin homologous protein 1 (WAVE1) in K562 leukemia cell invasion and its mechanism.</p><p><b>METHODS</b>Immunofluorescence method was used to detect the distribution of WAVE1 and MMP-2 in the cells. K562 cells were transfected with pcDNA3. 1-WAVE1 reconstructed plasmid or with specific siRNA to WAVE1 gene. The invasion ability of K562 cells was examined by Transwell assay. The expression level of WAVE1 and MMP-2 in K562 cells was assayed by real-time PCR and Western blot.</p><p><b>RESULTS</b>(1) WAVE1 and MMP-2 mainly expressed and co-localized in the cell membrane; (2) 24 h and 48 h after transfected with pcDNA3. 1-WAVE1, the MMP-2 mRNA level in K562 cells increased by 295% and 198% while its protein increased by 80% and 23% respectively as compared with control K562 cells. At the same time point after transfected with specific siRNA, the MMP-2 mRNA level decreased by 81% and 28%, and its protein decreased by 36% and 53% respectively as compared with control. (3) The invasion ability of K562 cells was enhanced after transfected with pcDNA3. 1-WAVE1 and depressed after transfected with the specific siRNA.</p><p><b>CONCLUSION</b>The co-localization of WAVE1 and MMP-2 in K562 cells suggests they coordinate in functions; WAVE1 may involve in the migration and invasion of K562 cells through regulating the expression level of MMP-2.</p>

Efficacy and prognosis analysis in 188 children with acute lymphoblastic leukemia of China / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze the therapeutic effect and the influencing factors of event-free survival (EFS) of childhood acute lymphoblastic leukemia (ALL) in Xiangya Hospital of Central South University and the First Affiliated Hospital of Guangxi Medical University.</p><p><b>METHODS</b>All the patients adopted chemotherapy according to therapeutic guideline revised by the Subspecialty Group of Hematology, The Society of Pediatrics, Chinese Medical Association for the second-time in 1998 (the Rongcheng ALL-98 Protocol). Kaplan-Meier method was used to estimate the survival rates of 188 patients who received therapy with good compliance. The differences of EFS between groups were assessed by Log-rank test. The independent influencing factors on EFS were analyzed by the Cox proportional hazards regression model.</p><p><b>RESULTS</b>After receiving inductive treatment, 354 of 374 (93.6%) patients demonstrated a complete remission; 188 patients who received complete courses of treatment with good compliance showed (68.1 +/- 5.6)% five-year EFS. Meanwhile, the five-year EFS in standard-risk (SR) group and high-risk (HR) group were (75.2 +/- 6.0)% and (47.6 +/- 11.6)%, respectively. The total relapse rate was 10.6% and the median time to relapse was 13 months. Twenty-nine of 188 patients (15.4%) were dead, and 13 patients (7.0%) died from treatment-related complications. Independent adverse prognostic factors included risk grouping, t (9; 22)/bcr-abl gene and leukocyte count.</p><p><b>CONCLUSIONS</b>The total EFS of childhood ALL patients treated with Rongcheng ALL-98 Protocol in two hospitals was close to 70%. Therefore, it is necessary to evaluate risk factors and consider the grouping in more detail to reduce the treatment-related mortality and to increase the compliance of treatment which can ultimately improve the EFS.</p>

Detection of human cyclin C gene expression in childhood acute lymphocytic leukemia using real-time fluorescence quantitative PCR / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the relationship between human cyclin C (CCNC) gene and childhood acute lymphocytic leukemia (ALL).</p><p><b>METHODS</b>The total RNA isolated from myeloid tissues of normal children and of children with newly diagnosed ALL and from ALL cell line 6T-CEM was reversely transcribed into cDNA. Real-time fluorescence quantitative PCR method was used to detect CCNC gene expression.</p><p><b>RESULTS</b>CCNC was expressed in myeloid tissues of normal children and of children with newly diagnosed ALL as well as 6T-CEM. The relative expression level of CCNC gene in children with newly diagnosed ALL was significantly lower than in normal controls (2.35 +/- 0.83 vs 13.5 +/- 0.30; P <0.05).</p><p><b>CONCLUSIONS</b>CCNC gene shows lower expression in children with newly diagnosed ALL, suggesting that it may be a tumor suppressing gene in childhood ALL.</p>

Expression of WAVE1 in childhood acute lymphocytic leukemia and in the apoptosis of Jurkat cells induced by adriamycin / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate whether WASP/Verprolin homologous protein 1 (WAVE1) plays a role in the pathogenesis of childhood acute lymphoblastic leukemia (ALL).</p><p><b>METHODS</b>WAVE1 mRNA and protein expression in bone marrow mononuclear cells (BMMCs) was measured by RT-PCR and Western blotting respectively in 4 children with ALL relapse, 15 children with ALL in complete remission (CR) and 40 children with newly diagnosed ALL. Ten normal bone marrow samples were used as controls. Jurkat cells were treated with different concentrations of adriamycin (ADM). The cell proliferation was detected with MTT. The apoptosis rate was measured by flow cytometry. WAVE1 mRNA and protein expression of Jurkat cells treated with ADM was detected by RT-PCR and Western blotting respectively.</p><p><b>RESULTS</b>WAVE1 was not expressed or weakly expressed in BMMCs from normal controls and patients with ALL in CR. Higher WAVE1 mRNA and protein expression was found in BMMCs from patients with newly diagnosed ALL and patients with relapse ALL when compared with the controls and the patients in CR (P<0.01). ADM significantly inhibited the proliferation of the Jurkat cells and the inhibitory effect was dose-and time-dependent (P<0.05). After ADM treatment for 24 hrs, the percentage of apoptosis cells increased significantly and WAVE1 mRNA and protein expression of Jurkat cells decreased significantly when compared with the untreated controls (P<0.05).</p><p><b>CONCLUSIONS</b>The WAVE1 expression increased in children with ALL. WAVE1 may be related to the development of ALL and may be severed as a marker for the evaluation of the severity of ALL in children.</p>

Enhancive effect of HMGB1 gene silence on adriamycin-induced apoptosis in K562/A02 drug resistance leukemia cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of high mobility group boxl (HMGBI) gene silence on adriamycin (ADM)-induced apoptosis in K562/A02 drug resistance leukemia cells.</p><p><b>METHODS</b>K562/ A02 cells were transient transfected with HMGB1- small interference RNA(siRNA) vector, and the levels of HMGB1 gene differential expression pre-and post-transfection were measured by RT-PCR and Western blotting. 50% inhibition concentration (IC50) of ADM on K562/A02 was determined by WST-8 assay. Cell apoptosis was assessed by flow cytometry. The release of Smac/DIABLO from the mitochondria to the cytoplasm was assayed by Western blotting. Activity of Caspase-3 was assayed with a Caspase Colorimetric Assay Kit.</p><p><b>RESULTS</b>(1) The HMGB1 expression at mRNA and protein levels in HMGB1 siRNA transfected K562/A02 cells were decreased by 86% and 71% respectively compared with control. (2) Suppression of HMGB1 by siRNA in K562/A02 cells resulted in a reversal of the resistance to ADM, and decreased IC50 from (4.83 +/- 0.08) microg/ml to (1.33 +/- 0.10) microg/ml. 1 microg/ml and 5 microg/ml of ADM treatment increased cell apoptotic rate by 27% and 32% respectively. (3) HMGB1 suppression in K562/A02 cells significantly promoted ADM- induced Smac/DIABLO release from the mitochondria to the cytoplasm, and increased the activities of Caspase-3.</p><p><b>CONCLUSION</b>HMGB1 gene silence can enhance sensitivity of K562/A02 cells to ADM and reverse cell resistant to ADM.</p>

High mobility group box 1 is increased in children with acute lymphocytic leukemia and stimulates the release of tumor necrosis factor-alpha in leukemic cell / 中华儿科杂志

<p><b>OBJECTIVE</b>Cytokine mediated cell immunity is the main mode of anti-tumor immunity in organism, and the disequilibrium of cytokine network is the main cause of tumor cells escaping immunologic surveillance. High mobility group box 1 (HMGB1), a nuclear protein, has recently been identified as an important mediator of local and systemic inflammatory diseases when released into the extracellular milieu. In the present study, the investigators explored the clinical significance of alteration in the serum levels of HMGB1 in childhood acute lymphocytic leukemia (ALL) and the mechanism of HMGB1-induced tumor necrosis factor (TNF)-alpha secretion in leukemic cells.</p><p><b>METHODS</b>The serum levels of HMGB1 in healthy children and childhood ALL were assayed by Western blotting. K562 leukemic cells were stimulated with recombinant HMGB1 protein in vitro, and the secretion of TNF-alpha was determined by using ELISA. The effects of HMGB1 on activation of p38, c-Jun amino-terminal kinase (JNK), and extracellular-signal regulated protein kinase (ERK) and mitogen-activated protein kinase (MAPK) in K562 cells were assayed by using Western blotting. The effects of inhibitors specific for the MAPK on HMGB1-induced TNF-alpha secretion were assayed by using ELISA.</p><p><b>RESULTS</b>The serum levels of HMGB1 were significantly higher in ALL initial treatment group (n = 15, 43.78 +/- 4.62 microg/ml) than those in healthy control group (n = 15, 0.60 +/- 0.48 microg/ml, P < 0.01) and ALL complete remission group (n = 15, 0.89 +/- 0.62 microg/ml, P < 0.01). No significant difference was found between the healthy control group and ALL complete remission group in HMGB1 levels (P > 0.05). TNF-alpha started to become detectable at 2 h and was still increasing at 16 h after HMGB1 (1 microg/ml) treatment in K562 cell culture. TNF-alpha was also secreted from K562 cells in a dose-dependent manner after HMGB1 (1 ng/ml-1 microg/ml) exposure. HMGB1 induced the phosphorylation of p38, JNK and ERK in k562 cells. Inhibitors specific for the JNK (SP600125), MEK (PD98059), and p38 MAPK (SB203580), abrogated HMGB1-induced TNF-alpha secretion.</p><p><b>CONCLUSIONS</b>The measurement of serum HMGB1 is helpful to evaluate the prognosis of the childhood ALL. HMGB1 stimulates leukemic cells to secrete TNF-alpha through a MAPK-dependent mechanism.</p>

Clinical data of childhood leukemia in Hunan Province between 2002 and 2005 / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study analyzed the clinical data of newly diagnosed childhood leukemia from various hospitals in the cities or counties of Hunan Province between 2002 and 2005 in order to provide references for further epidemiologic survey of childhood leukemia.</p><p><b>METHODS</b>The clinical data of children with newly diagnosed leukemia from hospitals of various cities or counties of Hunan Province between 2002 and 2005 were collected and reviewed.</p><p><b>RESULTS</b>There were 803 children with leukemia during 2002-2005. Acute lymphoid leukemia was most commonly seen (597/803, 74.35%), followed by acute non-lymphoid leukemia (192/803, 23.91%) and chronic myelocytic leukemia (14/803, 1.74%). There were no significant differences in the clinical type and the prevalence of leukemia between males and females. The prevalence of newly diagnosed childhood leukemia in the urban area was noticeably higher than that in the rural area (2.02/10(5) vs 1.50/10(5), P < 0.05). 41.79% of children with newly diagnosed leukemia from the urban area received treatments but only 22.80% of patients from the rural area received treatments (P < 0.05).</p><p><b>CONCLUSIONS</b>This study of patients-based hospitals showed some features of the morbidity of childhood leukemia in Hunan Province. It provides references for further epidemiologic investigation of this disease in Hunan Province.</p>

Clinical features and growth hormone receptor gene mutations of patients with Laron syndrome from a Chinese family / 中国当代儿科杂志

Laron syndrome is an autosomal recessive disorder caused by defects of growth hormone receptor (GHR) gene. It is characterized by severe postnatal growth retardation and characteristic facial features as well as high circulating levels of growth hormone (GH) and low levels of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3). This report described the clinical features and GHR gene mutations in 2 siblings with Laron syndrome in a Chinese family. Their heights and weights were in the normal range at birth, but the growth was retarded after birth. When they presented to the clinic, the heights of the boy (8 years old) and his sister (11 years old) were 80.0 cm (-8.2 SDS) and 96.6 cm (-6.8 SDS) respectively. They had typical appearance features of Laron syndrome such as short stature and obesity, with protruding forehead, saddle nose, large eyes, sparse and thin silky hair and high-pitched voice. They had higher basal serum GH levels and lower serum levels of IGF-I, IGFBP-3 and growth hormone binding protein (GHBP) than normal controls. The peak serum GH level after colonidine and insulin stimulations in the boy was over 350 ng/mL. After one-year rhGH treatment, the boy's height increased from 80.0 cm to 83.3 cm. The gene mutation analysis revealed that two patients had same homozygous mutation of S65H (TCA -->CCA) in exon 4, which is a novel gene mutation. It was concluded that a definite diagnosis of Laron syndrome can be made based on characteristic appearance features and serum levels of GH, IGF-I, IGFBP-3 and GHBP. The S65H mutation might be the cause of Laron syndrome in the two patients.

Role of WAVE1 in drug resistance of K562/A02 leukemia cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate if WAVE1 is involved in mult drug-resistance (MDR) of human leukemia cell line K562/A02.</p><p><b>METHODS</b>The level of WAVE1 in K562 and K562/A02 cells was assayed by Western blot and RT-PCR; K562 cells and K562/A02 cells were transient transfected with pEFBOS-WAVE1 reconstructed plasmid or specifically siRNA to WAVE1. 50% inhibition concentration (IC50) of doxorubicin on K562/A02 was determined by WST-8 assay. Hoechst33258 staining was used to examine cell morphological changes and to calculate percentage of apoptotic nuclei. The mRNA level of mdrl was assayed by RT-PCR. The Bcl-2 protein was assayed by Western blot.</p><p><b>RESULTS</b>1. The WAVE1 expression at mRNA and protein level in K562/A02 cells was increased by about 70% and 63% respectively as compared with that in K562 cells. 2. Overexpression of WAVE1 in K562 cells by transient transfection significantly increased the resistance to doxorubicin, and increased IC50 from (0.05 +/- 0.00) microg/ml to (2.99 +/- 0.12) microg/ml, and at 1 microg/ml or 5 microg/ml of doxorubicin treatment, cell apoptotic nuclei rate was decreased by 30% or 35% respectively. 3. Suppression of WAVE1 in K562/A02 cells by siRNA resulted in a reversal of MDR to doxorubicin, and decreased IC50 from (4.29 +/- 0.15) microg/ml to (1.85 +/- 0.07) microg/ml, and at 1 microg/ml or 5 microg/ml of doxorubicin treatment, cell apoptotic nuclei rate was increased by 24% or 21% respectively. 4. Overexpression of WAVE1 in K562 cells significantly increased the mdrl mRNA and the Bcl-2 protein, and suppression of WAVE1 in K562/A02 cells by siRNA decreased the mRNA and the protein.</p><p><b>CONCLUSION</b>WAVE1 involves in the MDR mechanisms in K562/A02 leukemia cells through regulation the level of mdrl and Bcl-2.</p>

Allelic loss of 6q16.3 microsatellite DNA in childhood acute lymphoblastic leukemia and bioinformatics analysis / 中华血液学杂志

<p><b>OBJECTIVE</b>To locate the cluster region of loss of heterozygosity (LOH) in children with acute lymphoblastic leukemia (ALL), and explore the new tumor suppressor gene.</p><p><b>METHODS</b>Allelic loss was analyzed by PCR with 15 microsatellite markers mapping on 6q16.3. The LOH was analyzed by bioinformatics. The relationship between LOH and clinical factors was further analyzed.</p><p><b>RESULTS</b>The frequency of LOH at least at one loci on 6q16.3 was 32.7%. The LOH in relapsed patients was higher than those in not relapsed. The higher frequency of LOH was observed in two regions of D6S1709-D6S1028 and D6S2160-D6S1580 at 6q16.3. GRIK2 may be a candidate of tumor suppressor gene. There are 12 ESTs may carry out new anti-oncogene. Patients with 6q LOH had higher WBC counts (P < 0.01), blast cells percentage (P < 0.01), relapse rate (P < 0.05) and chromosomal aberration (P < 0.05).</p><p><b>CONCLUSION</b>D6S1709-D6S1028 and D6S2160-D6S1580 are two regions of minimus deletion on 6q16.3 in which tumor suppressor gene may exist. The LOH on 6q16.3 may be a prognostic index of children with ALL.</p>