Mutational analysis of the cell cycle inhibitor Kip1/p27 in childhood leukemia

BACKGROUND: Cyclin-dependent kinases (CDKs) and cyclins, their regulatory subunits, govern cell-cycle progression in eukaryotic cells. Kip1/p27 is the main cyclin-dependent kinase inhibitor, which arrests cell division inhibiting G1-S transition. Kip1/p27 seems to play a critical role in the pathogenesis of several human malignancies and its lower expression has been shown to correlate with a poor prognosis in adult solid tumors. METHODS: Bone marrow blasts from 49 children with leukemia, 37 acute lymphoblastic leukemia (ALL), and 12 acute myeloid leukemia (AML) were studied. Exon 3 of Kip1/p27 was amplified using the polymerase chain reaction technique (PCR). Single strand conformational polymorphism and heterodouplex analysis were performed to detect DNA sequence with altered conformations and were subsequently sequenced to document mutations. RESULTS: Mutations in Kip1/p27 gene were detected in 2 out of 3 T-ALL, 6 out of 12 AML patients, and only 1 out of 34 B lineage ALL cases. Although the patient groups are small, a highly significant relation of the mutation status with the type of leukemia (P = 0.0037) and the risk group according to treatment protocols (P = 0.00021) was estimated. A statistically significant difference in the white blood count was observed (P = 0.019) between the mutated and non-mutated patient groups although no statistically significant association of the mutation status with the hemoglobin and platelets values, karyotype, age, sex, disease progression, and outcome was determined. CONCLUSIONS: Based upon these results, the Kip1/p27 mutations should be considered for further prospective testing as an additional parameter for risk stratification and treatment of childhood leukemia.     

Myeloproliferative Disorders with t(8;9)(p12;q33): A Case Report and Review of the Literature

The 8p11 myeloproliferative syndrome (EMS) is an aggressive neoplasm associated with chromosomal translocations involving the fibroblast growth factor receptor 1 tyrosine kinase gene on chromosome 8p11–12. The most frequent partner genes are in decreasing order of frequency: ZNF198 (or ZMYM2, zinc finger MYM type 2), CEP110 (centrosomal protein 110 kDa), FOP (or FGFR1OP, FGFR1 [fibroblast growth factor receptor 1] oncogene partner), and BCR (breakpoint cluster region) located on 13q12, 9q33, 6q27, and 22q11, respectively. Here the authors report a new case of translocation (8;9)(p12;q33) without lymphoma prior to the progression into acute leukemia. Currently, only patients underwent bone marrow transplantation stand a chance of long-term survival. In the future, FGFR1 inhibitor might be the specific and effective therapeutic target for EMS.     

Patient with terminal 9 Mb deletion of chromosome 9p: Refining the critical region for 9p monosomy syndrome with trigonocephaly

We describe a patient with typical manifestations of 9p monosomy syndrome, including trigonocephaly and sex reversal. Array comparative genomic hybridization (CGH) revealed a 9p terminal deletion of approximately 9 Mb with the breakpoint at 9p23. We compared the deleted segments of 9p associated with reported cases of 9p monosomy syndrome with trigonocephaly. We did not identify a region that was shared by all patients; however, when only pure terminal or interstitial deletions that did not involve material from any other chromosome were compared, we identified a segment from D9S912 to RP11‐439I6 of approximately 1 Mb that was deleted in every patient. We propose that this 1‐Mb segment might be the critical region for 9p monosomy syndrome with trigonocephaly.     

Increased p53 protein expression as a potential predictor of early relapse after hematopoietic stem cell transplantation in children with acute myelogenous leukemia

Dysregulation of genes involved in the cell cycle such as TP53, P21, P16, and PTEN plays a key role in oncogenesis. We have earlier reported increased expression of the TP53 encoded protein p53, in bone marrow samples from pediatric patients with more aggressive, rare chronic myeloid malignancies. The aim of this study was to investigate protein expression of p53, p21, p16, and PTEN before and after HSCT in pediatric patients with AML and evaluate whether any potential alterations could predict relapse after HSCT. Paraffin‐embedded bone marrow samples from 34 pediatric patients with AML were collected retrospectively from time of diagnosis as well as pre‐ and post‐HSCT. IHC was performed on tissue microarrays with antibodies against p53, p21, p16, and PTEN. Study material was analyzed by independent t‐tests and nonlinear regression. t‐Tests showed a statistical significant difference in p53 (p = 0.010) with overexpression in the group of patients who relapsed compared to the relapse‐free patients at >3–6 months post‐HSCT. Analysis of p53 protein expression by IHC may be a potential predictor for relapse after HSCT in children with AML.     

Pediatric histiocytic sarcoma clonally related to precursor B-cell acute lymphoblastic leukemia with homozygous deletion of CDKN2A encoding p16INK4A

Histiocytic sarcoma (HS) is a rare malignancy of tissue histiocytes with a dismal prognosis. We report a 4-year-old male who developed HS during maintenance chemotherapy for precursor B-cell acute lymphoblastic leukemia (pre-B ALL). Both tumors showed identical clonal immunoglobulin and T-cell receptor gene re-arrangement patterns, as well as homozygous deletion of the CDKN2A gene encoding p16(INK4A). These data suggest a clonal relationship between the two neoplasms despite their distinct lineages. Since CDKN2A deletion predisposes to development of HS in experimental models, the cytogenetic features of the patient's pre-B ALL may have predisposed to this change in lineage.     

12p三体新生儿1例临床及细胞分子遗传学分析

目的探讨12p三体新生儿的临床及细胞分子遗传学特点。方法回顾1例经外周血行淋巴细胞常规G显带染色体核型分析,高通量测序染色体组拷贝数分析(CNV)并经淋巴细胞间期荧光原位杂交(FISH)技术确认的12p三体新生儿的临床资料。结果患儿外周血染色体核型为47,XX,+mar,父母染色体核型均正常;CNV检出患儿12p13.33-p11.1(160 001～34 860 000)区域重复,片段大小为34.7 Mb;外周血淋巴细胞间期FISH显示患儿所有间期细胞核12号染色体短臂均存在3个信号,无嵌合体存在。确诊为12p三体。结论结合临床特征、外周血染色体核型分析、CNV及FISH技术可有效确诊12p三体。     

Relapsed childhood acute myeloid leukemia patient with inversion of chromosome 16 harboring a low FLT3 internal tandem duplication allelic burden and KIT mutations

Inversion of chromosome 16 [inv(16)] has a good prognosis in acute myeloid leukemia (AML), but additional genetic aberrations influence the outcome. We herein describe the case of a 15‐year‐old Japanese boy with inv(16) harboring a low‐allelic burden internal tandem duplication of FLT3 (FLT3‐ITD) and KIT mutations. Conventional chemotherapy eradicated a clone with a low‐allelic burden FLT3‐ITD mutation, although another clone with a KIT mutation occurred 17 months later. Further investigation is necessary to identify AML with inv(16) conferring poor prognosis, to facilitate appropriate treatment with additional drugs, such as dasatinib or gemtuzumab ozogamicin.     

Serum levels and differential expression of CD44 in childhood leukemia and malignant lymphoma: Correlation with prognostic criteria and survival

BACKGROUND: The CD44, a cell surface proteoglycan, participates in a variety of function including tumor dissemination and metastasis. However, there are no available data on the prognostic significance of CD44 expression of tumor tissue correlated with serum sCD44 level in childhood leukemias and lymphomas. METHODS: Serum levels and leukemic cell tumor tissue expression of CD44 were detected in 54 children with acute leukemia and malignant lymphoma. Serum samples were obtained from all patients before treatment and during remission. Twelve age-matched healthy children were included as a control group. RESULTS: The serum CD44 levels were significantly higher in patients with Hodgkin's disease (HD), non-Hodgkin's lymphoma (NHL), Burkitt's lymphoma (BL) and acute lymphoblastic leukemia (ALL) than those in the control group. The median values were 1627.0, 1336.0, 1318.5, 1730.4, 902.7 ng/mL, respectively, and P<0.001, P<0.01, P<0.01, P<0.05 in comparisons, respectively. However, there was no significant difference between acute myeloid leukemia (AML) and the control group (median values: 900.3 and 902.7 ng/mL, respectively, P>0.05). Serum sCD44 levels significantly declined in HD, NHL and ALL patients who were in complete remission (median values: 684.0, 573.8 and 1101.1 ng/mL, respectively, P<0.05 in each comparison). Patients with HD had higher levels of serum sCD44 and correlated well with higher erythrocyte sedimentation rate (ESR), B-symptoms and advanced-stage disease (P<0.05, P<0.05 and P<0.01, respectively). Expression of CD44 was significantly high in patients with HD and NHL who were in advanced stages of disease. High serum CD44 level was also associated with high tumor tissue expression of CD44 in patients with HD and BL. In addition, patients with higher levels of serum sCD44, had a poorer outcome and survival than those with lower sCD44 levels in HD and NHL groups. CONCLUSIONS: A high serum sCD44 level and/or tumor tissue expression at diagnosis is associated with poor prognostic criteria and/or unfavorable outcome in childhood leukemias and lymphomas.     

儿童急性白血病端粒酶活性与p15基因表达关系的研究(英文)

目的：探讨端粒酶活性与pINK4b(p15)基因表达在儿童急性白血病(AL)发病中的关系。方法：采用改良端粒重复序列PCR扩增和逆转录聚合酶链反应检测27例儿童AL骨髓单个核细胞端粒酶活性和p15基因表达情况,并与9例正常骨髓单个核细胞端粒酶活性及p15基因表达进行比较。结果：初诊时,AL患儿骨髓细胞端粒酶活性(34. 5±37. 0)TPG较对照组(2. 4±2. 2 )TPG明显增高(P<0. 001 ); AL患儿p15基因表达水平(9. 8±16. 2)%, 明显低于对照组(45. 8±16. 9)% (P<0. 001 )。AL患儿骨髓细胞端粒酶活性与p15基因表达水平之间无相关关系(r= 0.01304, P> 0. 05)。结论：端粒酶活化和p15基因表达水平降低与急性髓性白血病发展有关,但两者可能通过不同的机制作用于白血病。     

Concentrations of cat (Fel d 1), dog (Can f 1) and mite (Der f 1 and Der p 1) allergens in the clothing and school environment of Swedish schoolchildren with and without pets at home

To investigate whether our hypothesis that cat and dog owners bring allergens to public areas in their clothes was true or not, we studied the levels of Fel d 1, Can f 1, Der p 1 and Der f 1 in dust from the clothes and classrooms of children in a Swedish school. We also investigated the levels of allergen in different areas in the four classrooms used by the children. Thirty-one children were selected in four classes, forming three groups: cat owners, dog owners and children without a cat or dog at home. Furthermore, a group of children with asthma was included. Cat and dog allergens were detected in all 57 samples from clothes and classrooms. Mite allergen Der f 1 was detected in low concentrations in 6 out of 48 and Der p 1 in 5 out of 46 samples investigated. The concentrations of Can f 1 were higher than those of Fel d 1 in samples from clothes (geometric mean: 2676 ng/g fine dust and 444 ng/g) and classrooms (Can f 1: 1092 ng/g, Fel d 1: 240 ng/g). The dog owners had significantly higher concentrations of Can f 1 (8434 ng/g fine dust) in their clothes than cat owners (1629 ng/g, p <0.01), children without cat or dog (2742 ng/g, p < 0.05) and children with asthma (1518 ng/g, p < 0.001). The cat owners did not have significantly higher levels of Fel d 1 (1105 ng/g) in their clothes compared to the other three groups (D: 247 ng/g, nCnD: 418 ng/g, A: 386 ng/g) but the levels were significantly higher than for all children without a cat at home (345 ng/g, p < 0.05). No concentrations of mite allergen and low concentrations of Fel d 1 and Can f 1 were found in the children's hair. There were significantly higher concentrations of Fel d 1 and Can f 1 in dust from curtains than in samples from floors and bookshelves (p < 0.05). There was no significant difference between the allergen concentrations in samples from curtains and from desks and chairs, including the teachers' chairs, the only upholstered furniture in the rooms. Our results support the hypothesis that cat and dog owners bring allergens to public areas in their clothes and support other studies showing that textiles and upholstered furniture function as reservoirs of cat and dog allergens. Thus, children with asthma and other allergic diseases will be exposed to cat and dog allergens at school and by contact with pet owners, even if they avoid animal allergens at home.     

伴有t(12;21)易位的儿童急性淋巴细胞白血病的临床和实验研究

目的　研究我国儿童急性淋巴细胞白血病 (ALL)中伴有t(12 ;2 1)易位者的发生率及其临床、免疫学和预后的特征。方法　采用套式逆转录聚合酶链反应 (RT PCR)技术检测TEL AML1融合基因转录本 ,联合染色体R带核型分析和流式细胞仪免疫表型分析等方法。结果　在 5 5例儿童ALL(B系ALL 40例 ,T系ALL 13例 ,T、B系双表达ALL 2例 )中共发现 8例 (2 0 % )B系ALL有TEL AML1融合基因转录本 ,证实有t(12 ;2 1)易位存在。治疗后 8例均获完全缓解 (CR) ,随访至 1999年 5月 ,均在CR中 ,无一例复发。结论　t(12 ;2 1)B系ALL是儿童ALL中最多见且预后较好的一种亚型。RT PCR检测TEL AML1融合基因转录本是诊断t(12 ;2 1)ALL和监测其微小残留病最敏感有效的方法。     

急性淋巴细胞白血病患儿WAVE1和p22phox的表达及WAVE1与氧化应激的关系

目的：研究儿童急性淋巴细胞白血病（ALL）患者外周血单个核细胞(PBMCs)中WASP家族富含脯氨酸同源蛋白1（WAVE1）及NADPH氧化酶亚基p22phox的表达并探讨WAVE1表达与白血病病程及氧化应激的关系。方法：实时定量PCR法测定41例ALL儿童及10例正常对照儿童PBMCs中WAVE1和p22phox的表达水平。黄嘌呤氧化酶法（羟胺法）和二硫代二硝基苯甲酸法（DTNB法）分别测定外周血血浆总超氧化物歧化酶（SOD）活性和谷胱甘肽过氧化物酶（GSH-Px）活性。结果：①儿童ALL活动期组（初治+复发）PBMCs中WAVE1,p22phox的表达水平与正常对照组和完全缓解组相比均显著增高(P< 0.01); ALL完全缓解组中,WAVE1,p22phox表达高于正常对照组(P<0.05);②正常对照组、活动期组和缓解组血浆SOD活力分别为166.35±27.93, 22.62±7.39, 107.11±28.57 U/mL; GSH-Px活力分别为490.94±39.38,91.73±28.88,267.56±82.64 μmol/L。ALL活动期组外周血血浆总SOD,GSH-Px活性较完全缓解和正常儿童明显降低（P<0.01）;③ 随着WAVE1和p22phox的高表达,血浆中SOD, GSH-Px活性呈现下降趋势。WAVE1的表达水平与p22phox表达水平呈正相关（r=0.34,P< 0.05）,与血浆SOD,GSH-Px活性呈负相关（r分别为-0.336和-0.408,P<0.05）。结论：与正常对照组相比,WAVE1和p22phox在儿童ALL PBMCs中表达增高,而且其变化与ALL病程相关。ALL患儿氧化应激可能参与了WAVE1表达的调控。［中国当代儿科杂志,2009,11（2）：88-92］     

5例GNAO1基因相关疾病临床及遗传学分析

目的 总结分析GNAO1基因变异患者的遗传学与临床特征。方法 收集5例GNAO1基因变异患儿的临床资料,回顾性分析其基因变异特点、临床表现及治疗反应。结果 5例GNAO1基因变异患儿,3例为已知变异,2例为新发现的变异;除1例为剪切位点变异,其余4例均为错义突变。2例患儿表现为早发婴儿癫痫性脑病,同时伴有不同程度的运动障碍;3例患儿以锥体外系症状为主要表现(2例表现为肌张力不全,1例表现为手足徐动),暂无癫痫发作;5例患儿均存在严重的智力运动发育落后。2例癫痫患儿应用多种抗癫痫药物治疗无效;2例主要表现为肌张力不全的患儿,进行了深部脑刺激(DBS)手术治疗,其中1例术后1个月的Burke-Fahn-Marsden肌张力障碍评分(BFMDRS)较术前改善了32.36%,另1例术后改善不明显,术后12个月BFMDRS评分仅降低了7.79%;1例以手足徐动为主要表现的患儿,年龄尚小,预计后期行DBS治疗。结论 GNAO1基因变异患者的临床表型存在异质性,主要表现为发育迟滞、以锥体外系症状为主的运动障碍和/或癫痫发作。该基因变异所致的锥体外系症状以及癫痫发作对药物治疗反应差,DBS可缓解部分患...     

20p12.2缺失致Alagille综合征患儿临床和肝脏病理分析

目的分析20p12缺失致Alagille综合征(ALGS)患儿的临床表现和肝脏病理。方法回顾分析1例20p12微缺失致ALGS患儿的临床资料。结果患儿,男,1月龄起病,以胆汁淤积为首发表现,伴特殊面容,蝶形椎,肾脏和心脏病变;肝脏穿刺术病理学检测提示肝脏淤胆改变,肝细胞中度损害(G2S3),无胆管减少表现。采集患儿及父母血标本,采用二代基因测序检测发现chr20p12.2:(9288462-10654178)处1.36 Mb的杂合缺失,缺失片段中包含JAG1基因,为新发突变。确诊后予以对症支持治疗,随访半年,患儿生长发育无异常,黄疸仍迁延不退,远期预后有待进一步随访。结论ALGS是一种常染色体显性遗传病,临床表现多样,基因检测和肝活检有助于诊断。