Paired box 5 increases the chemosensitivity of esophageal squamous cell cancer cells by promoting p53 signaling activity / 中华医学杂志(英文版)

BACKGROUND@#Gene promoter methylation is a major epigenetic change in cancers, which plays critical roles in carcinogenesis. As a crucial regulator in the early stages of B-cell differentiation and embryonic neurodevelopment, the paired box 5 (PAX5) gene is downregulated by methylation in several kinds of tumors and the role of this downregulation in esophageal squamous cell carcinoma (ESCC) pathogenesis remains unclear.@*METHODS@#To elucidate the role of PAX5 in ESCC, eight ESCC cell lines, 51 primary ESCC tissue samples, and eight normal esophageal mucosa samples were studied and The Cancer Genome Atlas (TCGA) was queried. PAX5 expression was examined by reverse transcription-polymerase chain reaction and western blotting. Cell apoptosis, proliferation, and chemosensitivity were detected by flow cytometry, colony formation assays, and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assays in ESCC cell lines with PAX5 overexpression or silencing. Tumor xenograft models were established for in vivo verification.@*RESULTS@#PAX5 methylation was found in 37.3% (19/51) of primary ESCC samples, which was significantly associated with age (P = 0.007) and tumor-node-metastasis stage (P = 0.014). TCGA data analysis indicated that PAX5 expression was inversely correlated with promoter region methylation (r = -0.189, P = 0.011 for cg00464519 and r = -0.228, P = 0.002 for cg02538199). Restoration of PAX5 expression suppressed cell proliferation, promoted apoptosis, and inhibited tumor growth of ESCC cell lines, which was verified in xenografted mice. Ectopic PAX5 expression significantly increased p53 reporter luciferase activity and increased p53 messenger RNA and protein levels. A direct interaction of PAX5 with the p53 promoter region was confirmed by chromatin immunoprecipitation assays. Re-expression of PAX5 sensitized ESCC cell lines KYSE150 and KYSE30 to fluorouracil and docetaxel. Silencing of PAX5 induced resistance of KYSE450 cells to these drugs.@*CONCLUSIONS@#As a tumor suppressor gene regulated by promoter region methylation in human ESCC, PAX5 inhibits proliferation, promotes apoptosis, and induces activation of p53 signaling. PAX5 may serve as a chemosensitive marker of ESCC.

Research progress in Ph-like childhood acute lymphoblastic leukemia / 中国当代儿科杂志

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a subtype of B-lineage ALL (B-ALL) that displays a gene expression profile (GEP) similar to Philadelphia chromosome-positive ALL (PhALL). It has a diverse range of genetic alterations that activate cytokine receptor genes and kinase signaling pathways, frequently accompanied by abnormal transcription factors related to lymphatic development. Children with Ph-like ALL account for 15% of children with high-risk B-ALL. It has adverse clinical features and a poor prognosis. Tyrosine kinase inhibitors combined with chemotherapy can significantly improve the prognosis of children with PhALL, suggesting that targeted therapy based on the molecular cytogenetic abnormalities of Ph-like ALL has good research prospects. This paper expounds the genetic alterations, pathogenesis, clinical features, diagnostic measures, and potential therapeutic approaches of Ph-like childhood ALL based on recent research progress in Ph-like ALL.

Significance of PAX5 deletion in childhood B-lineage acute lymphoblastic leukemia without reproducible chromosomal abnormalities / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To identify the incidence of PAX5 deletion in childhood B-lineage acute lymphoblastic leukemia (B-ALL) without reproducible chromosomal abnormalities and to investigate the association between PAX5 abnormalities and prognosis of ALL.</p><p><b>METHODS</b>Multiplex ligation-dependent probe amplification was used to determine the copy numbers of PAX5 gene in children newly diagnosed with B-ALL without reproducible chromosomal abnormalities between April 2008 and April 2013 and controls (children with non-hematologic diseases or tumors). The patients were classifiied into deletion group and non-deletion group based on the presence of PAX5 deletion.</p><p><b>RESULTS</b>Eighteen (21%) out of 86 children with B-ALL had PAX5 deletion. The deletion group had a significantly higher total white blood cell count at diagnosis than the non-deletion group (P=0.001). The Kaplan-Meier analysis demonstrated that the deletion group had a significantly lower disease-free survival (DFS) rate than the non-deletion group (0.69±0.12 vs 0.90±0.04; P=0.017), but there was no significant difference in the overall survival rate between the two groups (P=0.128). The Cox analysis showed that PAX5 deletion was a risk factor for DFS (P=0.03).</p><p><b>CONCLUSIONS</b>PAX5 deletion is an independent risk factor for DFS in B-ALL children without reproducible chromosomal abnormalities.</p>

The First Case Report of Composite Bone Marrow Involvement by Simultaneously Developed Peripheral T-Cell Lymphoma, Not Otherwise Specified, and Diffuse Large B-Cell Lymphoma

No abstract available.

Mutation and expression of PAX5 gene in adult acute lymphoblastic leukemia / 中国实验血液学杂志

PAX5 is an important transcription factor of paired-box(PAX) family. The aim of this study was to investigate the mutations and expression of PAX5 and its clinical significance in adult patients with acute lymphoblastic leukemia (ALL). Reverse transcription polymerase chain reaction (RT-PCR) and genomic PCR were performed to detect the deletions of PAX5 and point mutations of PAX5 exon 2-10 in 101 cases of adult ALL and were confirmed by cloning and sequencing. In addition, quantitative PCR (qPCR) was performed to evaluate the expression of PAX5. Furthermore, the correlations of mutations and expression of PAX5 with clinical parameters were analyzed, and the prognostic significance was evaluated as well. The results showed that PAX5 mutations were observed in 8 of 101 (7.9%) patients with B-ALL. A total of 9 types of mutations were detected, including 4 types of deletions, 4 types of point mutations and 1 insertion mutation; percentage of patients with age ≥ 50 years was higher in PAX5 mutation group than in wide-type group (62.5% vs 21.5%,P = 0.031) . The statistical differences were observed in B-cell subtype, initial platelet count and immunophenotypes between high and low expression of PAX5 (P < 0.05) . In addition, patients with high expression of PAX5 had higher first complete remission rate (86.7% vs 62.5%, P = 0.030) and 6-month overall survival rate (75.0% vs 50.0%, P = 0.034) compared with patients with low expression of PAX5. It is concluded that deletion/insertion/point mutations and aberrant expression of PAX5 can be observed in adult patients with B-ALL. Mutations and aberrant expression of PAX5 correlated with clinical parameters and have important clinical significance.

Grey zone lymphoma with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma: clinicopathologic characterization of 16 cases showing different patterns / 中华病理学杂志

<p><b>OBJECTIVE</b>To profile the clinicopathologic features of a series of grey zone lymphoma (GZL) cases with hybrid features of diffuse large B-cell lymphoma (DLBCL) and classical Hodgkin lymphoma (CHL), with a purpose to gain an in-depth understanding of the borderline B-cell neoplasm.</p><p><b>METHODS</b>The clinical, morphologic and immunophenotyical characteristics of 16 cases were retrospectively analyzed.</p><p><b>RESULTS</b>The patients were mostly male adults, with a male to female ratio of 1.7: 1.0 and a mean age of 40.2 years. Eight patients presented with peripheral nodal lesions and five cases with mediastinal involvement. Histologically and immunophenotypically, the 16 cases were classified into three sub-categories. In 4 cases, the morphologic features resembled CHL more closely, but the neoplastic cells showed uniform and intense positive staining of CD20 (pattern 1). Although the initial impression of the other 8 cases was that of DLBCL, the expression levels of CD20 and PAX5 were variable, and CD30 or CD15 was positive (pattern 2). A characteristic feature of pattern 3, observed in the remaining 4 cases, demonstrated a broad spectrum of morphology with hybrid features of both CHL and DLBCL. The neoplastic cells in pattern 3 were positive for CD20, CD30 and CD15. EBV-LMP1 was detected in 6 of the 11 tested cases. Clinically, most patients with GZL seemed insensitive to immuno-chemotherapy of the R-CHOP regimen.</p><p><b>CONCLUSIONS</b>The diagnostic criteria for GZL with features intermediate between DLBCL and CHL is proposed by the three histologic patterns commonly seen in these lesions. Cases presented with peripheral lesions might differ from those with mediastinal presentation pathologically. At current time, there is no effective treatment for these borderline B-cell lymphomas and the prognosis is poor.</p>

A Chinese patient with relapsed and refractory Hodgkin lymphoma treated with brentuximab vedotin / 癌症

At present, approximately 20% of Hodgkin lymphomas (HL) are relapsed and refractory, and therapeutic methods including chemotherapy, radiotherapy, and even stem cell transplantation are unsatisfactory. Brentuximab vedotin, composed of CD30 antibody and a chemotherapeutic agent, is a new targeted drug that eradicates tumor cells by binding to the CD30 antigen on their surface. In clinical trials, the response rate and complete remission rate of this drug were 73% and 40%, respectively, for relapsed and refractory HL. Here we report a case of CD30-positive relapsed and refractory HL that was treated with brentuximab. Before the treatment with brentuximab, the patient underwent chemotherapy, radiotherapy, and autologous stem cell transplantation. However, the disease continued to progress, affecting multiple organs and prompting symptoms such as persistent fever. After the treatment with brentuximab, the patient's condition improved. Body temperature returned to normal after 4 days. Lung nodules were reduced in size and number after a single course of treatment, and PET/CT showed partial remission and complete remission after 3 and 6 courses of treatment, respectively. The entire treatment process progressed smoothly, though the patient experienced some symptoms due to chemotherapy, including peripheral neuritis of the limbs, irritating dry cough, and mild increase in aminotransferase. No serious adverse effects were observed. The current general condition of the patient is good; the continuous complete remission has amounted to 6 months.

Deletions and rearrangements of PAX5 gene in B-lineage acute lymphoblastic leukemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the frequency paired-box domain 5 (PAX5) gene alterations in B-lineage acute lymphoblastic leukemia (B-ALL) harboring 9p abnormalities and its implication for clinical prognosis.</p><p><b>METHODS</b>Bacterial artificial chromosomes RP11-344B23 and RP11-652D9 encompassing the PAX5 gene were selected. DNA was extracted with conventional method and labeled with fluorescein by nicking transition. Fluorescence in situ hybridization (FISH) was used to determine the rearrangement or deletion of the PAX5 gene in B-ALL harboring chromosome 9p abnormalities. Clinical and laboratory features of patients were analyzed.</p><p><b>RESULTS</b>Fifty cases were analyzed with FISH. Complete deletion was observed in 23 patients (46%), partial deletion was observed in 2 patients (4%), and rearrangement was detected only in 1 case. The total frequency of abnormalities was 52% (26/50). No significant difference was found in clinical features of patients with or without PAX5 rearrangement or deletion.</p><p><b>CONCLUSION</b>The frequency of PAX5 gene alterations in B-ALL harboring 9p abnormalities was 52%. However, no significant difference was found between patients with and without PAX5 alterations.</p>

Clinicopathologic study of 40 cases of mediastinal tumours of haematopoietic and lymphoid tissues / 中华病理学杂志

<p><b>OBJECTIVE</b>To study clinical and histopathological features, and diagnosis of mediastinal tumours of haematopoietic and lymphoid tissues (MTHL).</p><p><b>METHODS</b>Forty cases of MTHL were analyzed for clinicopathology by microscopy and immunohistochemical staining and in situ hybridization, according to the updated 2008 WHO classification of tumours of haematopoietic and lymphoid tissues.</p><p><b>RESULTS</b>In 40 cases of MTHL, there were 20 males and 20 females. The ratio of male/female was 1:1. The mean age was 31.8 years and median age was 29 years (range, 12 - 70 years).Superior vena cava syndrome was observed in 28 cases. The specimens of 4 cases were obtained by lumpectomy, whereas 36 cases by biopsy (25 cases by thoracoscopy, 1 by core needle aspiration). Twenty cases lay in anterior mediastinum, and 2 in posterior, 1 in superior, 8 in anterior and superior, 2 in posterior and superior, 2 in anterior and middle, 1 in middle and anterior mediastinum.Frozen section were performed in 28 cases, and 17 cases were diagnosed as tumours of haematopoietic and lymphoid tissues (consistency ratio was 60.7%). Twelve cases were classical Hodgkin lymphomas (cHL) (8 were nodular sclerosis subtype, and 3 were mixed cellarity, 1 was lymphocyte-rich subtype), and 10 were primary mediastinal (thymic) large B cell lymphoma (PMBCL), 10 were precursor lymphocyte neoplasm [8 were T lymphoblastic leukemia/lymphomas (T-LBL), 2 were B-LBL], 1 was MALT lymphoma, 1 was composite lymphoma (PMBCL and cHL), 2 were myeloid sarcomas, 4 were gray zone lymphomas (GZL) (3 had morphology reminiscent of cHL, and 1 of DLBCL, all cases were positive for CD20, PAX5, CD30 and CD15).EBER were detected in 11 cases by in situ hybridization, 2 of which were positive (18.2%), and the 2 positive cases were cHL.</p><p><b>CONCLUSIONS</b>MTHLs occur predominantly in adolescents and young adults, mainly present as superior vena cava syndrome and anterior mediasinal masses. cHL, PMBCL, T-LBL were the most common MTHLs.GZLs mainly occur in young adults, those whose morphology reminiscent of cHL, immunohistochemistry reminiscent of PMBCL, and vice versa. Thoracoscopy, frozen section and a suitable panel of antibodies were practical approaches to MTHL.</p>

Clinicopathologic features of lymphoplasmacytic lymphoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To explore the clinicopathologic features of lymphoplasmacytic lymphomas (LPL).</p><p><b>METHODS</b>Routine histological examination was performed on hematoxylin-eosin stained sections of 24 bone marrow biopsies and available 6 concurrent lymph node specimens. Immunohistochemistry study was performed using EliVision methods.</p><p><b>RESULTS</b>Among 24 cases, the male-to-female ratio was 2.4:1 and the median age was 59.5 years (42 - 75). The most common symptom was weakness (83.3%, 20/24). Hyperviscosity and "B" symptoms occurred in 20.8% (5/24) and 8.3% (2/24) respectively. 41.7% (10/24) patients presented with lymphadenopathy. Anemia, leukocytosis and thrombocytopenia were seen in 79.2% (19/24), 8.3% (2/24) and 37.5% (9/24) respectively. Monoclonal Ig light chain expression was detected by serum immunofixation electrophoresis in 23 cases (95.8%), including IgM (20 cases), IgG (2 cases) and IgA (1 case). Basing on the histology and immunohistochemistry findings, the diagnosis was made in 22 bone marrow and 2 lymph node biopsies, respectively. Histologically, the bone marrow and lymph node specimens composed of small lymphocytes, plasmacytoid lymphocytes and plasma cells. The most frequent pattern of bone marrow involvement was diffuse in appearance (63.6%, 14/22), while nodular and interstitial patterns were less common (22.7%, 5/22 and 13.6%, 3/22, respectively). Lymph node involvement was also to be diffuse in pattern. The proliferative cells expressed Pax5, CD20, CD38 and CD138, but were negative for CD5, CD10, CD23, CyclinD1, CD3, CD7 and MPO.</p><p><b>CONCLUSIONS</b>LPL has distinct clinicopathological features. Histological and immunohistochemistry findings are important for its differential diagnosis with chronic lymphocytic leukemia/small lymphocytic lymphoma, splenic marginal zone lymphoma and follicular lymphoma. Waldenström macroglobulinemia is LPL.</p>

Clinicopathologic study of 128 cases of T-lymphoblastic lymphoma/leukemia / 中华病理学杂志

<p><b>OBJECTIVE</b>To clarify clinical and morphological features and immunophenotype of T lymphoblastic lymphoma/leukaemia (T-LBL/ALL) and to further improve the knowledge and diagnostic accuracy for T-ALL/LBL.</p><p><b>METHODS</b>128 cases of T-LBL/ALL were analyzed for the clinical features, morphology, immunophenotype and TCR gene rearrangement using routine eosin and haematoxylin stain, immunohistochemistry and polymerase chain reaction combining with the clinical findings.</p><p><b>RESULTS</b>In 128 cases of T-LBL/ALL, there were 94 male and 34 female. The ratio of male/female was 2.8:1. The age of patients ranged from 4 to 88 years, with an average of 27 years and a median of 22 years. Lymph nodes and extranodal areas were involved in 58/128 and 27/128 cases of T-LBL/ALL, respectively. The other 43 cases had involvement of both nodal and extranodal areas. Cervical node and mediastinum were involved in 74 cases and 43 cases, respectively. Diffuse growth pattern of tumor cells was predominant. Nodular growth pattern was seen only in a few cases. Most cases composed of small to medium-sized lymphoblasts, and other 7 cases showed a composition of large lymphoblasts. Tumor cells expressed TdT in 121/128 (94.5%) cases, CD34 in 48/98 (49.0%) cases, CD3 in 78/108 (72.2%) cases, CD7 in 104/108 (96.3%) cases, CD43 in 56/63 (88.9%) cases, CD79a in 5/70 (7.1%) cases, CD10 in 25/76 (32.9%) cases, CD99 in 58/60 (96.7%) cases and Pax-5 in 4/91(4.4%) cases. All of the cases were negative for MPO. A follow up data, ranging from 1 to 53 months, was obtained in 51/128 (39.8%) patients. The over all survival rate was 68.6% and the median survival time was 12 months. Under a similar condition of carrying a positive staining result on CD3 in tumor cells, there was a statistically significant difference between patients in the group of over 30 of age and that with the age ranging from 11 to 30. Patients associating with a CD10 positive staining of tumor cells showed also a shorter survival period. In addition, there were 4 out of 5 cases showing the presence of TCR gene rearrangement.</p><p><b>CONCLUSIONS</b>T-LBL/ALL are aggressive in behavior, associating mainly with enlarged cervical lymph nodes and masses in the mediastinum, occurring predominantly in children and young adults. Although small to medium-sized tumor cells with diffuse pattern were found in most cases, however, large-sized tumor cells and nodular pattern could also be obtained in a few cases. Immunohistochemistry staining particularly adoption of CD7, Pax-5, TdT, CD34 and Ki-67 stainings in combination are helpful of making a diagnosis for T-LBL/ALL. Analysis of TCR gene rearrangement will be helpful for the diagnosis of a few difficult cases.</p>

Effect of pax5 gene blocked by RNAi on biological characteristics of B cell malignant lymphoma / 中国实验血液学杂志

This study was aimed to investigate the biological characteristics of B hematological tumor cells such as proliferation, immunological phenotype and apoptosis by silencing pax5. The specific pax5 small hairpin RNA (shRNA) was synthesized by in vitro transcription. For evaluating the inhibition efficiency, the expression change at mRNA and protein levels were assessed by real-time RT-PCR and Western blot respectively. To detect the biological characteristics of pax5-silenced hematological tumor cells, the immunological phenotype, apoptosis and cell proliferation were measured by using real-time RT-PCR, MTT assay and flow cytometry respectively. The results showed that two shRNA were synthesized, both of which were effective to block pax5 expression. After being blocked by RNAi the immunological phenotype of pax5-silenced lymphoma cells was changed, the expressions of CD19 mRNA and protein were reduced, but the expression of IgM was not changed. As compared with control group, the effect on proliferation and apoptosis of lymphoma cells not could be detected after pax5 silencing. It is concluded that the pax5 plays important role in late differentiation of B cells, and may participate in signal transduction of lymphoma cells, but the effect on proliferation and apoptosis of lymphoma cells were not detected after RNAi, which need to be elucidated further.

Gene rearrangements in follicular lymphoma among Indonesian.

AIM: Gene rearrangement has an important role in the management of lymphoma. We investigated the rearrangements of B-cell leukaemia/lymphoma 2 (BCL2), BCL6 and Paired homeobox 5 (PAX5) genes in Indonesian follicular lymphoma (FL) patients. METHODS: We examined gene rearrangements using various kinds of polymerase chain reactions (PCRs) on 24 patients' peripheral blood DNA. RESULTS: BCL2 rearrangement was found in 58% (14 of 24 patients), 8 at mbr (major breakpoint region), 2 at mcr (minor cluster region) and 4 at icr (intermediate cluster region), respectively. No rearrangement in BCL6 and PAX5 was detected. There was a significant difference in the incidence of spleen involvement between patients with BCL-2 rearrangement and without it (50% vs. 11%, p=0.04). BCL-2 rearrangement was correlated with spleen involvement (OR=9) and anemia (OR=2.3). CONCLUSION: BCL2 rearrangement in Indonesian FL was higher than previous reports from other Asia countries (58% vs. 48%, respectively). Our method using peripheral blood DNA might be useful for the molecular diagnosis of FL.

Expression of the transcription factor PAX5 in childhood acute leukemic cells / 中国实验血液学杂志

To investigate transcription factor PAX5 expression characteristics in childhood acute leukemic cells, expression levels of PAX5 and CD19 mRNA in 6 hematological tumor cell lines and bone marrow cells of 6 normal children, 58 de novo patients and 4 relapse acute leukemic children, including 39 cases of B-ALL, 10 cases of T-ALL and 13 cases of AML, were detected by a real-time RT-PCR. The results showed that PAX5 and CD19 mRNA expression levels were 2.35% and 2.52% in Namalwa (B-cell lines) respectively, but almost not detectable in other T- and myeloid cell lines. Among clinical samples, expression of PAX5 mRNA in B-ALL was significantly higher than that in T-ALL and AML (P = 0.029 and P = 0.013 respectively). PAX5 expression was significantly lower in T-ALL and AML than that in normal controls. The difference of PAX5 mRNA expression levels between T-ALL and AML was not significant. Individual difference of PAX5 mRNA expression levels in children with B-ALL was great. Moreover, PAX5 mRNA expressions in de novo and relapse patients with B-ALL were significantly higher than those in remission (P = 0.011 and P = 0.006 respectively). As binding sites for B-cell specific activator protein have been identified in the promoter regions of CD19, the study found that in B-ALL, there was clear correlation between the expression levels of PAX5 and CD19, which was also studied by real-time RT-PCR. It is concluded that PAX5 transcripts are readily detectable and quantifiable in clinical materials with B-ALL by real-time RT-PCR. The strong PAX5 mRNA expression in some B-ALL can be considered to be particularly interesting for further analysis.

Expression of B cell-specific activator protein in lymphomas / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the expression of B cell-specific activator protein (BSAP)/Pax-5 in lymphomas.</p><p><b>METHODS</b>One hundred and two cases of diffuse large B-cell lymphoma (DLBCL), 3 cases of follicular lymphoma (FL), 3 cases of extranodal marginal zone B-cell lymphoma, 1 case of nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), 10 cases of anaplastic large cell lymphoma (ALCL) and 10 cases of plasmacytoma were studied immunohistochemically for BSAP and CD20.</p><p><b>RESULTS</b>The tumor cells in the 102 cases of DLBCL all expressed CD20, amongst which 100 cases also expressed BSAP. Three cases of FL, 3 cases of extranodal marginal zone B-cell lymphoma and 1 case of NLPHL also expressed BSAP and CD20. All the ALCLs and plasmacytomas did not express BSAP and CD20. The expression rates of CD20 and BSAP were highly consistent. The intensity of staining showed no statistical significance.</p><p><b>CONCLUSIONS</b>BSAP/Pax-5 is a novel B-cell marker expressed in tumor nuclei of B-cell lymphomas. Though less sensitive than CD20, anti-BSAP has diagnostic value in routine surgical pathology practice.</p>

Explore the origin of H/RS cells on protein and gene / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the origin and clonality of H/RS cells.</p><p><b>METHODS</b>Immunohistochemical method was used to detect the expression of B-cell-specific activator protein (BSAP) and CD(20) in 33 paraffin-embedded tissues of classical Hodgkin lymphoma (cHL). IgH gene rearrangement was detected in 33 paraffin-embedded cHL tissue and 6 microsectioned H/RS cell samples. The PCR products of a case of cHL and its microsectioned cells were sequenced.</p><p><b>RESULTS</b>H/RS cells were positive for BSAP in 30 of 33 (90.91%) cHL cases and positive for CD(20) in 10/33 (30.30%) cases. There was a significant difference between the expression of BSAP and CD(20) in H/RS cells (P = 0.000). BSAP and CD(20) were positive in almost all B cells of lymph node reactive hyperplasia and malignant cells in B-cell lymphomas while were negative in all malignant cells of T-cell lymphomas. 16 of 33 cHL were positive for gene rearrangement, and microsectioned H/RS cells in 14 of 19 tubes displayed clonal bands of rearrangement. There was no significant difference among the rearrangement rates in tubes containing different numbers of H/RS cells (P = 0.280). Sequencing analyses of the PCR products from both paraffin-embedded tissue and microsection of the same patient revealed the rearranged V segments, but the sequences were not identical.</p><p><b>CONCLUSION</b>H/RS cells were originated from B cells of different differentiation stage.</p>

Sequence analysis of 5'-flanking region of human pax-5 gene exon 1B / 中国实验血液学杂志

Pax-5 gene is important transcription factor in B-lymphopoiesis and B-cell development. To understand the regulatory mechanism of pax-5 expression, the immediate 5'-flanking region (6 671 bp) of human pax-gene exon 1B was isolated and characterized. Analysis of the total sequence showed that the proximal promoter includes 3 CAT boxes, 1 SP1 and 1 E box. However, there was no consensus sequence for a TATA box in the 5'-flanking region. Putative regulatory sites of further upstream in the sequence revealed 6 LMO(2)COM, 5 NFAT, 2 LPOLYA-B, 3 GATA1, 2 AP4, 10 MZF1, 1 ETS1-B, 1 GATA3, 1 NKX25, 2 RORA1, 1 LYF1, 2 Ikaros2, 2 TCF11, 1 GATA-C and 1 FREAC7. Therefore, the 5'-flanking region of human pax-5 exon 1B could be involved in regulating the expression of human pax-5 and B-cell differentiation and development.