[Analysis of Factors Influencing Overall Survival of MDS Patients Transplanted with HSCs].

OBJECTIVE: To analyze the effect of clinical features, routine laboratory examination and related gene mutation on the OS of patients with myelodysplastic syndrome (MDS) after hematopoietic stem cell transplantation (HSCT). METHODS: 121 patients diagnosed as MDS and underwent hematopoietic stem cell transplantation in the First Affiliated Hospital of Soochow University from October 2013 to August 2018 were selected. Basic information of the patients was collected, and blood cells, bone marrow blasts at initial diagnosis, chromosomal karyotypes and gene mutations of the patients were detected.The effect of different factors on overall survival (OS) was analyzed by statistical method. RESULTS: Kaplan-Meier univariate analysis shows that OS was significanly different among different age groups. The 3-year OS rate of patients aged 0-29 years was (83.3±7.7) %, the 3-year OS rate in patients aged 30-49 years was (58.1±7.7 %), and the 3-year OS rate of patients aged 50-69 years was (31.0±22.6) %, which was statistically different (P＜0.05) between different groups. There were also significant differences in OS among patients with different transplantation types. 3-year OS rate: HLA-matched sibling HSCT＞unrelated HLA-matched HSCT＞haploidentical HSCT＞micro HSCT. The OS rate of patients with bone marrow blasts≥10% seems lower than blasts＜10%, but there was no statistical difference.The 3-year OS rate of patients with chromosomal karyotype complex abnormality was (47.7±11.5) %, and that of patients without complex abnormality was (80±4.2) % which was statistical difference (P＜0.05). Patients with DNMT3A, NRAS, TP53 and GATA2 mutations had shorter OS time compared with patients without mutation of these genes, which shows statistically significant (P＜0.05). COX multivariate analysis showed that age, chromosome karyotype, DNMT3A, TET2, GATA2 and NRAS were the independent factors influencing OS of patients after HSCT, with statistically significant difference. CONCLUSION: age of patients, donor selection of HSCT, chromosome karyotype, DNMT3A, NRAS, TP53, GATA2 and TET2 gene mutations are all independent factors affecting the OS of patients after HSCT. Therefore, the assessment of the OS of MDS patients with transplantation requires comprehensive consideration.

Methylation level of Rap1GAP and the clinical significance in MDS.

Previous studies on the pathogenesis of myelodysplastic syndrome (MDS) have identified multiple associated gene mutations, including mutations of tetmethylcytosinedioxygenase 2, isocitrate dehydrogenase [NADP(+)] 1 cytosolic, isocitrate dehydrogenase [NADP(+)] 2 mitochondrial and additional sex combs like 1 transcriptional regulator, all of which may be considered epigenetic regulators. Furthermore, mutations of RAS type GTPase family genes have been identified in 10-15% patients with MDS. The authors' previous study on the gene expression profile of cluster of differentiation 34+ cells using microarray analysis identified elevated expression of RAP1GTPase activating protein 1 (Rap1GAP) in patients with MDS compared with that in non-malignant blood diseases (NM) control group. To further investigate the mechanism of increased Rap1GAP expression, the methylation pattern of the promoter of this gene was determined in 86 patients with MDS (n=29), acute myeloid leukemia (AML) (n=31) or NM (n=26) using bisulfite-specific polymerase chain reaction and DNA sequencing. The results demonstrated that the methylation of Rap1GAP occurred in all 29 patients with MDS at multiple CpG sites. The methylation level of Rap1GAP in patients with MDS was decreased compared with that in patients with NM. Significant differences at 4CpG sites (5,7,8 and 12) of Rap1GAP promoter were identified between MDS and NM. Furthermore, based on the present clinical records of the patient cohort, the methylation status of Rap1GAP promoter did not appear to be associated with the clinicopathological characteristics of patients with MDS, including age, gender and International Prognosis Score System. The difference in methylation level at CpG site 8 of Rap1GAP promoter was identified to be significantly increased in patients with MDS-refractory anemia with ring sideroblasts compared with that in the MDS-refractory cytopenia with multilineage dysplasia or MDS-unclassified groups. The results of the present study suggest that patients with MDS exhibit a lower overall methylation level within Rap1GAP promoter compared with patients with NM or AML. In addition, the methylation level at the four identified CpG sites can distinguish between MDS and NM.

Coexistence of p210BCR-ABL and CBFß-MYH11 fusion genes in myeloid leukemia: A report of 4 cases.

Numerous acquired molecular and cytogenetic abnormalities are strongly associated with hematological malignancies. The breakpoint cluster region-ABL proto-oncogene 1 (BCR-ABL) rearrangement leads to a p210 chimeric protein in typical chronic myeloid leukemia (CML), whereas 17-25% of patients with acute lymphocytic leukemia and 0.9-3% patients with de novo acute myeloid leukemia (AML) carry a p190BCR-ABL fusion protein. Cases of patients with AML/CML carrying two specific primary molecular changes, BCR-ABL and core binding factor-ß-myosin heavy chain 11 (CBFß-MYH11) fusion genes have been rarely reported. The present study aimed to understand the nature and mechanism of this particular type of leukemia through case reports and literature review. A total of four patients who were diagnosed as AML/CML with BCR-ABL and CBFß-MYH11 fusion genes in the First Affiliated Hospital of Soochow University (Suzhou, China) between January 2004 and December 2012 were examined. Morphological analysis of bone marrow cells, flow cytometry, quantitative polymerase chain reaction of p210BCR-ABL and CBFß-MYH11 transcripts as well as cytogenetic and fluorescence in situ hybridization analyses were performed. A total of 4 patients who exhibited fusion of p210BCR-ABL and CBFß-MYH11 were identified. A single patient (case 1) was first diagnosed CML-acute phase (AP), which progressed rapidly to CML-blast crisis (BC), and three patients (cases 2, 3 and 4) were diagnosed with AML with bone marrow eosinophilia at first presentation with no evidence of previous onset of CML. All cases achieved remission following conventional chemotherapy/hematological stem cell transplantation combined with the inhibitor of tyrosine kinase (TKI) maintenance therapy. The patients with CML carrying and expressing BCR-ABL and CBFß-MYH11 fusion genes appeared more likely to rapidly progress to AP or BC. Therefore, the product of the CBFß-MYH11 fusion gene may serve an important role in the transformation of CML. The co-expression of p210BCR-ABL and CBFß-MYH11 fusion genes in myeloid leukemia may be a molecular event occurring not only during the development of CML, but also in AML.

[Differentiation of K562 Cells Induced by Pulsatilla Saponin A into Erythroid Lineage].

OBJECTIVE: To explore the differentiation-inducing potentiality of Pulsatilla saponin A on K562 cells. METHODS: Pulsatilla saponin A of different concentrations was used to treat K562 cells; the benzidine staining and the hemoglobinometry were applied to measure the change of hemoglobin content; the flow cytometry (FCM) was used to detect the expression of CD71 and GPA on K562 cells. RESULTS: K562 cells treated with 4 µg/ml pulsatilla saponin A differentiated into the erythroid lineage. With the treatment of pulsatilla saponin A, the hemoglobin content in K562 cells increased significantly; CD71 and GPA expression on the K562 cell surface were up-regulated. CONCLUSION: Pulsatilla saponin A can induce K562 cells to differentiate into erythroid lineage.

[Clinical Analysis on Treatment of Chronic Myelomonocytic Leukemia with Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To analyze retrospectively the therapeutic efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for chronic myelomonocytic leukemia (CMML). METHODS: The engraftment, graft versus host disease (GVHD), infection, relapse, and survival of 13 CMML patients received allo-HSCT were observed. The clinical outcome of allo-HSCT for CMML was analyzed. RESULTS: Thirteen (10 males and 3 females) CMML patients with a median age of 38 years old received allo-HSCT including 4 from HLA-matched unrelated donors, 6 from HLA-matched sibling donors and 3 from haploidentical related donors. All 13 patients achieved engraftment, and the median time of neutrophil engraftment and platelet engraftment were 12 (11-18) days and 15 (10-55) days respectively, acute GVHD occurred in 8 patients. After the median follow-up of 13 (6-29) months, the overall survival, disease free survival and relapse were 53.8%, 53.8%, 7.7%, respectively. CONCLUSION: Allo-HSCT can improve the survival of patients with CMML, and is a effective method for treatment of CMML.

Long intergenic non-coding RNA induced by X-ray irradiation regulates DNA damage response signaling in the human bronchial epithelial BEAS-2B cell line.

Long non-coding RNAs (lncRNAs) have been regarded as the primary genetic regulators of several important biological processes. However, the biological functions of lncRNAs in radiation-induced lung damage remain largely unknown. The present study aimed to investigate the potential effects of lncRNAs on radiation-induced lung injury (RILI). Female C57BL/6 mice were exposed to 12 Gy single doses of total body irradiation (TBI). LncRNA microarray screening was conducted at 24 h post-irradiation (IR) to investigate the differentially-expressed lncRNAs during RILI. Following the subsequent bioinformatics analysis and reverse transcription-polymerase chain reaction (RT-PCR) validation, one of the verified differentially-expressed long intergenic radiation-responsive ncRNAs (LIRRs), LIRR1, was selected for further functional study. The normal human bronchial epithelial BEAS-2B cell line was used as the cell model. The recombinant eukaryotic expression vector for the lncRNA was designed, constructed and transfected using lipofectamine. RT-PCR, clonogenic and flow cytometry assays, immunofluorescence detection and western blot analysis were performed to reveal the role of the lncRNA in the radiosensitivity regulation of the RILI target cells. In lung tissues 24 h after 12 Gy TBI, six of the identified differentially-expressed LIRRs near the coding genes were validated using quantitative (q)PCR. The upregulation of two LIRRs was observed and confirmed using qPCR. LIRR1 was chosen for further functional study. Following the stable transfection of LIRR1, identified through G418 screening, increased radiosensitivity, evident cell cycle G1 phase arrest and increased γ-H2AX foci formation were observed in the bronchial epithelial BEAS-2B cell line subsequent to IR. LIRR1 overexpression also led to decreased expression of the KU70, KU80 and RAD50 DNA repair proteins, marked activation of p53, decreased mouse double minute 2 homolog (MDM2) expression, and substantially induced p21 and suppressed cyclin-dependent kinase 2 in BEAS-2B following IR. Subsequent to the use of Pifithrin-α, a specific inhibitor of p53 activation, increased MDM2 expression was observed in the LIRR1-overexpressing cells, suggesting that LIRR1 could mediate the DNA damage response (DDR) signaling in a p53-dependent manner. The present study provides a novel mechanism for RILI, using the concept of lncRNAs.

Growth and differentiation effects of Homer3 on a leukemia cell line.

The Homer protein family, also known as the family of cytoplasmic scaffolding proteins, which include three subtypes (Homer1, Homer2, Homer3). Homer3 can regulate transcription and play a very important role in the differentiation and development for some tissues (e.g. muscle and nervous systems). The current studies showed that Homer3 abnormal expression changes in acute myeloid leukemia (AML). Forced expression of Homer3 in transfected K562 cells inhibited proliferation, influenced the cell cycle profile, affected apoptosis induced by As2O3 through inhibition of Bcl2 expression, and also promoted cell differentiation induced by 12-O-tetra decanoylphorbol-acetate (TPA). These results showed that Homer3 is a novel gene which plays a certain role in the occurrence and development of AML.

[Biocompatibility of polyethylene imine (PEI)-coated magnetic Fe3O4 nanoparticles in SHI-1 cells].

OBJECTIVE: To explore the feasibility of magnetic resonance cell imaging technology by using polyethylene imine (PEI)-coated magnetic nanoparticles of Fe4O4 (PEI-Fe4O4-MNPs) to track cell biology behavior. METHODS: Endocytic PEI-Fe4O4-MNPs in SHI-1 cells were observed by transmission electron microscopy (TEM) . Iron contents of nano-labeled cells were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Prussian blue staining. The proliferation ability of labeled cells was detected by cell counting kit-8 (CCK-8) assay; the differentiation and colony-forming abilities were also observed. SHI-1 cells without endocytosing PEI-Fe4O4-MNPs were used as control. RESULTS: Our data showed that PEI-Fe4O4-MNPs could label SHI-1 cells. The labeling efficiency depended on the nanoparticles' concentration and the duration of cells treating. Inhibition rates of SHI-1cells labeled by 60-100 µg Fe/ml PEI-Fe4O4-MNPs were much higher than of 5-50 µg Fe/ml ones following treating by 5-100 µg Fe/ml PEI-Fe4O4-MNPs for 48 hrs. The expressions of CD11b and CD14 were (78.4±18.5)% and (18.7±2.9)% in control vs (83.3±14.2)% and (20.4±2.1)% in cells fractions treated by 30 µg Fe/ml PEI-Fe4O4-MNPs. Clony-forming rates of SHI-1 cells labeled by 0, 20 , 50 µg Fe/ml PEI-Fe4O4-MNPs were (25.20±7.22)%, (25.93±13.15)%, (23.37±9.33)%, respectively. Differentiation and colony-forming potentials of labeled cells were similar with control in the certain range of PEI-Fe4O4-MNPs concentration. CONCLUSION: SHI-1 cells were efficiently labeled by PEI-Fe4O4-MNPs with well biocompatibilities in proper range of concentration, the latter could be coupled with magnetic resonance imaging (MRI) to track cells in vivo.

A c.464T>a mutation in VHL gene in a Chinese family with VHL syndrome.

Von Hippel-Lindau (VHL) is a tumor suppressor that negatively regulates the production of angiogenic factors. Mutations in the VHL gene cause VHL syndrome, which is characterized by highly vascularized tumors. Here we report a c.464T>A mutation of the VHL gene in three patients with hemangioblastoma from a Chinese family. This mutation was not reported previously and was absent in the unaffected family members. The mutation is predicted to cause Val to Glu substitution at VHL protein residue 155 in a conserved region. Previous biochemical studies demonstrated that residue Val-155 was critical for VHL protein binding to chaperonin TRiC/CCT, an essential step for proper VHL protein folding. Our finding of naturally occurring VHL V155E mutation in patients with VHL syndrome supports the functional importance of Val-155 residue in VHL protein and illustrates the diversity of VHL gene defects underlying VHL syndrome.

[Significance of interplay between Rap1 and cadherin to the development of myelodysplastic syndrome].

OBJECTIVE: To explore the hematopoietic pathophysiology of myelodysplastic syndrome (MDS) at stem/progenitor cell level by analyzing the gene expression profiles associated with hematopoiesis. METHODS: The differentially expressed genes which were involved in the hematopoiesis were screened by microarray using CD34(+) cells from MDS patients firstly. RQ-PCR was then applied to validate the screened genes using CD34(+) cells from MDS-RA patients who had normal karyotype. The linkages with hematopoiesis among these validated genes were analyzed. RESULTS: Among the differentially expressed genes in CD34(+) cells of MDS-RA patients, Rap1GAP was up-regulated significantly (P < 0.01). Cadherins, which can interplay with Rap1, including N-cadherin and E-cadherin, were down-regulated significantly (P < 0.01). ß-catenin, a downstream effector of cadherins, was highly expressed in MDS-RA patients (P < 0.01). c-myc binding protein was down-regulated (P < 0.01), and c-myc promoter binding protein was up-regulated (P < 0.01). Rac1, Rac2 and Cdc42, which belong to RhoGTPases family and are associated with the cell morphology and hematopoiesis, were all expressed highly in MDS-RA patients (P < 0.01). CONCLUSION: The abnormal expression of cadherin, ß-catenin and c-myc associated genes were closely related to the dysplastic hematopoiesis of MDS. The down regulation of cadherin was associated with the positive feedback mechanism between Rap1 and cadherin. The aberrant expression of Rac1, Rac2 and Cdc42 may contribute to the morphological dysplasia of MDS.

[Monitoring the expression ratio of AML1-ETO9a isoform in t(8;21) acute myeloid leukemia and its significance].

OBJECTIVE: To study the expression ratio of AML1-ETO9a (AE9a) isoform in t(8;21) acute myeloid leukemia (AML) and its clinical significance. METHODS: Bone marrow samples from 44 newly diagnosed t(8;21) AML patients co-expressed AE9a and AE were screened by RT-PCR. The alteration of the AE9a expression ratio was monitored during follow-up by using quantitative real-time RT-PCR (qPCR). RESULTS: The expression level of AE9a was markedly lower than that of AE in these patients. There was a positive correlation between the expression level of AE9a and AE in most of bone marrow samples. The transcript level of both AE9a and AE was decreased in the 44 patients after one course of standard chemotherapy, but the percentage of AE9a expression level was increased in comparison with that before treatment (P < 0.05). After one course of standard chemotherapy treatment, the percentage of AE9a in incomplete remission (ICR) patients was significantly higher than that in CR patients (P < 0.05). Relapsed patients had a higher AE9a ratio than the unrelapsed patients (P < 0.05). During the remission, the percentage of AE9a in 11/17 relapsed patients obviously elevated even while the expression of AE fusion gene at low level. CONCLUSIONS: AE9a and AE co-expressed in most of AML patients with t(8;21) translocation. The expression level of AE9a was lower than that of AE, and there is a positive correlation between the expression level of these two isoforms. The sensitivity of AE9a gene to the standard chemotherapy is less than that of the AE fusion gene. Monitoring the AE9a to AE ratio during the CR can predict the early relapse of the disease compared to monitoring the AE alone.

[C-kit, NPM1 and FLT3 gene mutation patterns and their prognostic significance in 656 Chinese patients with acute myeloid leukemia].

OBJECTIVE: To evaluate the prevalence and distribution of C-kit, NPM1 and FLT3 gene mutations in patients with acute myeloid leukemia (AML), and to analyze the relationship between the gene mutations and their prognosis. METHODS: Mutations in exon 8 and 17 of C-kit gene, exon 12 of NPM1 gene, exon 20 of FLT3-TKD gene, and exon 14/15 of FLT3-ITD gene were detected by direct sequencing. Clinical data was collected and followed up if the patient had accepted treatment in our hospital. RESULTS: Among the 656 AML patients, mutations in C-kit exon 8 were found in 6 patients (0.9%), C-kit exon 17 in 33 (5.0%), NPM1 in 169 (25.8%), FLT3-TKD in 46 (7.1%), and FLT3-ITD in 178 (27.1%). Six subtypes of mutations were detected in C-kit exon 8, 8 in C-kit exon 17, 11 in FLT3-TKD, 15 in NPM1, of which 5 were not reported before. C-kit exon 17 mutations were more frequently detected in patients with t(8;21) and exon 8 in patients with inv(16) cytogenetic abnormality. No other gene mutations except FLT3 were detected in M(3) patients. NPM1 and ITD mutations were often detected in individuals with normal cytogenetics or M(5) and M(1) of FAB classification, and accompanied with high white blood cell counts in peripheral blood, high blast counts in bone marrow and low CD34 expression. The older the patients were when diagnosed, the more gene mutations and the higher white blood cell count were detected. More mutations were found in individuals with normal karyotype than that with other karyotypes. It appeared that FLT3-ITD was significantly associated with shorter overall survival (OS) (P = 0.004), NPM1 was not significantly associated with OS, but NPM1(+)/ITD(-) patients had the longest OS. CONCLUSIONS: Our results showed that the mutation types and amounts had particular distribution in MICM subtypes, and were associated with white blood cell counts in peripheral blood, blast counts in bone marrow and prognosis. Especially for patients with normal karyotype, the genetic mutations could be new molecule marker.

[Construction of AML1-ETO eukaryotic expression vector and its effects on proliferation and differentiation of U937 cells].

OBJECTIVE: To construct a pcDNA3.1-AML1-ETO expression vector and investigate its effects on proliferation and differentiation of U937 leukemic cells. METHODS: AML1-ETO gene was amplified by PCR from pCMV5-AML1-ETO and inserted into eukaryotic expression plasmid pcDNA3.1/V5-His-TOPO. The recombinant plasmid was transfected into U937 cells by Lipofectamin 2000. Individual clones selected with G418 were isolated. The integration and the expression levels of AML1-ETO in transfectants were determined by PCR, RT-PCR and Western blot analysis respectively. Trypan blue refusal staining method was used to detect the proliferation of U937 cells. Light microscope was applied to observe the morphologic changes of the cell. The expression of myeloid cell differentiation antigen was detected using flow cytometry. RESULTS: The recombinant pcDNA3.1-AML1-ETO was confirmed by enzyme digestion and sequencing. The highly expressing AML1-ETO subclone was established. AML1-ETO was expressed in U937 cells transfected with pcDNA3.1-AML1-ETO. The growth of the monoclonal cells was inhibited evidently (P < 0.05). The expression of CD11b in transfected group \[(4.17 ± 0.31)%\] was lower than that in empty plasmid transfected group and non-transfected group \[(11.40 ± 0.17)% and (11.03 ± 0.15)%\] respectively (P < 0.001). Transfected cells displayed morphology of less differentiation. The expression level of CDl1b was unchanged in transfected cells treated with TPA (P > 0.05). CONCLUSION: The eukaryotic expression vector for AML1-ETO gene was successfully constructed and expressed in U937. AML1-ETO inhibits the proliferation and differentiation of transfected cells. It provides the basis for further study of mechanisms of AML1-ETO in leukemogenesis.

Accelerated cellular senescence in myelodysplastic syndrome.

OBJECTIVE: To investigate the contribution of cellular senescence to the progression and prognosis of myelodysplastic syndrome (MDS). MATERIALS AND METHODS: We have analyzed the expression of p16INK4a in bone marrow mononuclear cells or CD34(+) cells from 53 patients with MDS, 12 acute myeloid leukemia (AML), and 11 healthy controls. Additionally, We have assessed quantitatively senescence-associated beta-galactosidase (SA-beta-gal) staining on bone marrow mononuclear cells from MDS and AML patients, HL60 and SHI-1 leukemia cell lines, and healthy control cells. RESULTS: An upregulated expression of senescence-associated molecular marker p16INK4a was found in MDS compared with healthy controls, while a lower expression of p16INK4a was observed in AML compared with healthy controls. International Prognostic Scoring System score was negatively correlated with the percentage of p16INK4a-positive cells. The SA-beta-gal activity measured by mean percentage of positive cells was significantly higher in MDS cases when compared with controls. Meanwhile, percentage of SA-beta-gal-positive cells was also remarkably higher in dysplastic cells of MDS when compared to nondysplastic cells from MDS. CONCLUSIONS: These results of our present study suggested an accelerated cellular senescence occurred in MDS, and the cellular senescence may be involved in the progression and prognosis of MDS.

Regulatory function and expression of rap1gap gene in hematopoietic cells-review.

Rap1 is a small G protein belonging to the RAS superfamily. Rap1 signalling has effects on cell growth, cell proliferation and involves in regulation of the mitogen activated protein (MAP) kinase or ERK (extracellular signal regulated kinase) cascade. Rap1 will directly activate ERK through B-Raf. B-Raf is a member of Raf family, and presents in neuronal and hematopoietic cells. Oncogenic mutations of gene RAS are most frequent and detected in 20% - 30% of human leukemias and 10% - 15% of MDS cases. The review summarizes the regulatory function of Rap1 in development of hematopoietic cells and effect of Rap1 in hematologic malignancies.

Protein RAP1GAP in human myelodysplastic syndrome detected by flow cytometry and its clinical relevance.

Previous study on the gene expression profile of human MDS by using microarray discovered that transcription of RAP1GAP was up-regulated, which was confirmed by quantitative RT-PCR in expanding cohort of MDS patients. This study was pourposed to investigate the expression of RAP1GAP in human MDS and its clinical relevance. The expression of RAP1GAP in bone marrow cells of 19 MDS patients was detected by flow cytometry and was compared with that in patients with non-malignant blood diseases and acute leukemias, meanwhile the relevance between expression level of RAP1GAP and hemoglobin, leukocytes, platelets, blasts percentage in bone marrow cells and IPSS score was analyzed. The results indicated that the expression level of RAP1GAp in MDS patients significantly increased as compared with patients with non-malignant blood diseases or AML (8.42 +/- 8.37% vs 2.97 +/- 4.75% or 2.26 +/- 4.24%). Among MDS patients, the expression level of RAP1GAP in MDS-RA was significantly higher than that in MDS-RAEB (11.64 +/- 9.07% vs 4.37 +/- 4.65%). However, no definitive correlation of expression level with above-mentioned clinical parameters was found in detected patients with DMS. In conclusion, the expression of RAP1GAP in MDS patients obviously increases, the relationship between expression level of RAP1GAP and laboratory hematological parameter and IPSS score does not be confirmed. The role played by RAP1GAP expression in the pathogenesis of MDS and its clinical significance during progression of MDS towards AML deserves further studies.

[Detection of clonal immunoglobulin and T-cell receptor gene rearrangements in newly diagnosed adult patients with acute lymphoblastic leukemia by using multiplex PCR protocols].

OBJECTIVE: To provide the evidence of RQ-PCR-based assessment of minimal residual disease (MRD), the clonal immunoglobulin and T-cell receptor (Ig/TCR) gene rearrangements were identified in newly diagnosed adult patients with acute lymphoblastic leukemia (ALL) by multiplex PCR protocols. METHODS: Forty newly diagnosed adult patients with B-lineage (B-) and T cell (T-) ALL were involved in this study. All DNA samples were obtained from the bone marrow (BM) mononuclear cells (MNC). IgH, IgK, TCRB, TCRG and TCRD gene rearrangements were detected by BIOMED-2 multiplex PCR protocols, which included 96 different primers and 14 multiplex PCR tubes. RESULTS: The clonal immunoglobulin (Ig) rearrangements were found in 96% of B-ALL, 86% being IgH and 14% IgK. While in T-ALL, clonal TCR rearrangements were found in all of the patients, 83% being TCRB, 78% TCRG and 39% TCRD. More than two clonal markers were found in 91% of B-ALL and 89% of T-ALL patients. CONCLUSIONS: The detection rate of clonal rearrangements using the BIOMED-2 14 multiplex PCR tubes is high, which can detect virtually all clonal B and T-cell proliferations. It can be used for diagnostic clonality studies as well as for the identification of PCR targets suitable for the detection of minimal residual disease.

Up-regulation of DLK1 as an imprinted gene could contribute to human hepatocellular carcinoma.

Dysregulation of a genomic imprinting gene can contribute to carcinogenesis. Here, delta-like 1 homolog (Drosophila) (DLK1), a paternally expressed gene, was found to be significantly up-regulated in 60 (73.2%) of a total of 82 hepatocellular carcinoma (HCC) specimens using reverse transcription-polymerase chain reaction. In addition, immunohistochemistry staining was performed in another 88 HCC specimens, of which 50 (56.8%) cancerous tissues were considered as positive. The expression of DLK1 was obviously induced in HCC cells, Bel-7402 and MHCC-H, by a demethylation agent, 5-aza-2'-deoxycytidine. Furthermore, both demethylation of the DLK1 promoter (-565 to -362) and hypermethylation of the imprinting control domain in the region upstream of maternally expressed gene 3 were identified in a few HCC specimens. This implies that deregulation of genomic DNA methylation of the imprinted domain could be attributed to the up-regulation of DLK1 in HCC, although the undoubtedly complex mechanisms involved in the epigenetic event should be further investigated in HCC. Surprisingly, the expression of DLK1 in HCC was confirmed to be monoallelic specific, not biallelic, in three HCC specimens with a single nucleotide polymorphism as at T852C (rs2295660). Importantly, the exogenous DLK1 can significantly promote the cell proliferation of SMMC-7721 cells, a HCC cell line, whereas the suppression of endogenetic DLK1 through RNA interference can markedly inhibit cell growth, colony formation and tumorigenicity of HepG2, Hep3B and HuH-7 cells. These data suggest that DLK1 as an imprinted gene could be significantly up-regulated in HCC due to certain epigenetic events and contribute to the oncogenesis of this tumor.

cDNA microarray reveals signaling pathways involved in hormones expression of human pituitary.

Pituitary, a master gland of neuroendocrine system, secretes hormones that orchestrate many physiological processes, under the regulation of multiple signaling pathways. To investigate the genes involved in hormones expression of human pituitary, homemade cDNA microarray containing 14,800 human genes/ESTs were used to profile the gene expression in both fetal and adult pituitaries. Seven hundred and twelve known genes changed over 2-fold between the both tissues. Of which, 23 genes were changed with hormones expression in aging were confirmed by RT-PCR, not only the known regulators such as Pit1, GATA4, ESRRA, GABA-A, and EMK, but also LOC55884, DUSP3, PNN, and RCL, which had not been reported to be involved in the hormones expression. Correspondingly, the mRNAs of GH, PRL, POMC, TSH-beta, FSH-beta, and LH-beta, was increased as much as 6- to 20-fold in adult pituitary than those in fetal pituitary, by real-time quantitative RT-PCR assay. In addition, the mRNAs of signaling pathways, such as cAMP-PKA-CREB, PI3K-Akt, and PKA-ERK were further investigated. Of them, it was only cAMP-PKA-CREB pathway, but not PI3K-Akt and PKA-ERK have the same expressing pattern as hormones. It suggested that cDNA microarray is highly advantages to profile the differential expressed genes that were involved in hormones expression of human pituitary, but it might ignore some responding proteins regulated posttranscriptionally.