Proteome Landscapes of Human Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma.

Liver cancer is among the top leading causes of cancer mortality worldwide. Particularly, hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (CCA) have been extensively investigated from the aspect of tumor biology. However, a comprehensive and systematic understanding of the molecular characteristics of HCC and CCA remains absent. Here, we characterized the proteome landscapes of HCC and CCA using the data-independent acquisition (DIA) mass spectrometry (MS) method. By comparing the quantitative proteomes of HCC and CCA, we found several differences between the two cancer types. In particular, we found an abnormal lipid metabolism in HCC and activated extracellular matrix-related pathways in CCA. We next developed a three-protein classifier to distinguish CCA from HCC, achieving an area under the curve (AUC) of 0.92, and an accuracy of 90% in an independent validation cohort of 51 patients. The distinct molecular characteristics of HCC and CCA presented in this study provide new insights into the tumor biology of these two major important primary liver cancers. Our findings may help develop more efficient diagnostic approaches and new targeted drug treatments.

Quantitative proteomics reveals differential biological processes in healthy neonatal cord neutrophils and adult neutrophils.

Neonatal neutrophils are characterized by the immaturity of bactericidal mechanisms that contributes largely to neonatal mortality. However, underlying molecular mechanism associated with the immaturity remains incompletely understood. In this study, we performed comparative proteomic analysis on neonatal neutrophils derived from human cord blood and adult peripheral neutrophils. A total of 1332 proteins were identified and quantified, and 127 proteins were characterized as differentially expressed between adult and cord neutrophils. The differentially expressed proteins are mapped in KEGG pathways into five clusters and indicated impaired functions of neonatal neutrophils in proteasome, lysosome, phagosome, and leukocyte transendothelial migration. In particular, many proteins associated with NETosis, a critical mechanism for antimicrobial process and auto-clearance, were also found to be downregulated in cord neutrophils. This study represents a first comparative proteome profiling of neonatal and adult neutrophils, and provides a global view of differentially expressed proteome for enhancing our understanding of their various functional difference.

Comparison of microRNA expression profiles in HCC-derived microvesicles and the parental cells and evaluation of their roles in HCC.

To determine whether the microRNAs (miRNAs) contained in cancer-derived microvesicles (MVs) mirror those of the parental tumor cells, we compared the miRNA expression profiles of MVs derived from their parental hepatocellular carcinoma (HCC) cells. The presence and levels of 888 miRNAs from SMMC-7721 cells and MVs were detected by Agilent miRNA microarray analysis. Four selected miRNAs were verified by real time qRT-PCR. Furthermore, the genes of the miRNAs were bioinformatically identified to explore potential roles of the miRNAs in HCC microenvironment. Our results showed that miRNAs expression profiles of MVs derived from HCC were significantly changed. Of all the miRNAs tested, 148 miRNAs were co-expressed in MVs and SMMC-7721 cells, only 121 and 15 miRNAs were detected in MVs and SMMC-7721 cells, respectively. Among the 148 co-expressing miRNAs, 48 miRNAs had the similar expression level and 6 of them were supposed to be oncogenic or suppressive miRNAs. According to the target prediction by Quantile Algorithm method, these miRNAs may regulate 3831 genes which were closely related to cell cycle, apoptosis and oncogenesis, and 78 were known tumor suppressors or oncogenes. Gene ontology (GO) analysis indicated that 3831 genes were mainly associated with nucleic acid binding, cell death, cell adhesion. MVs containing miRNAs, released into the HCC microenvironment, bear the characteristic miRNAs of the original cells and might participate in cancer progression.

Cytotoxic effect of trans-cinnamaldehyde on human leukemia K562 cells.

AIM: To investigate the effects of trans-cinnamaldehyde (TCA) on the human leukemia K562 cell line and the cytotoxicity of cytokine-induced killer (CIK) cells against K562 cells. METHODS: Apoptosis, Fas expression, and mitochondrial transmembrane potential in K652 cells were analyzed using flow cytometry. K562 cells were labeled with CFSE. The cytotoxic effect of expanded CIK cells on CFSE-labeled K562 cells was determined by FACS flow cytometry. RESULTS: Treatment with TCA 180 micromol/L for 9 h induced apoptosis in 8.9%+/-1.23% of K562 cells. Treatment with 120 or 180 micromol/L TCA for 24 h significantly increased the apoptotic cells to 18.63%+/-1.42 % and 38.98%+/-2.74%, respectively. TCA significantly upregulates Fas expression and decreases mitochondrial transmembrane potential in K562 cells. TCA treatment at 120 and 180 micromol/L for 9 h enhanced the percentage of lysis of K562 cells by expanded CIK cells from 34.84%+/-2.13% to 48.21%+/-2.22 % and 64.81%+/-3.22% at the E:F ratio of 25:1 and from 49.26%+/-3.22% to 57.81%+/-5.13% and 73.36%+/-5.98% at E:F ratio of 50:1. CONCLUSION: TCA exerts cytotoxic effects on human leukemia K562 cells by inducing apoptosis and synergizing the cytotoxicity of CIK cells against K562 cells. These properties of TCA are beneficial to the treatment of leukemia, even in the patients who have received hematopoietic stem cells transplantation (HSCT).

Identification of Protein Abundance Changes in Hepatocellular Carcinoma Tissues Using PCT-SWATH.

PURPOSE: To rapidly identify protein abundance changes in biopsy-level fresh-frozen hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: The pressure-cycling technology (PCT) is applied and sequential window acquisition of all theoretical mass spectra (SWATH-MS) workflow is optimized to analyze 38 biopsy-level tissue samples from 19 HCC patients. Each proteome is analyzed with 45 min LC gradient. MCM7 is validated using immunohistochemistry (IHC). RESULTS: A total of 11 787 proteotypic peptides from 2579 SwissProt proteins are quantified with high confidence. The coefficient of variation (CV) of peptide yield using PCT is 32.9%, and the R2 of peptide quantification is 0.9729. Five hundred forty-one proteins showed significant abundance change between the tumor area and its adjacent benign area. From 24 upregulated pathways and 13 suppressed ones, enhanced biomolecule synthesis and suppressed small molecular metabolism in liver tumor tissues are observed. Protein changes based on α-fetoprotein expression and hepatitis B virus infection are further analyzed. The data altogether highlight 16 promising tumor marker candidates. The upregulation of minichromosome maintenance complex component 7 (MCM7) is further observed in multiple HCC tumor tissues by IHC. CONCLUSIONS AND CLINICAL RELEVANCE: The practicality of rapid proteomic analysis of biopsy-level fresh-frozen HCC tissue samples with PCT-SWATH has been demonstrated and promising tumor marker candidates including MCM7 are identified.

CD4+CD25high regulatory cells in peripheral blood of cancer patients.

AIM: Regulatory T cells (Treg) that prevent autoimmune diseases by suppression of self-reactive T cells may also suppress the immune response against cancer. Experimental tumor models in mice revealed that Tregs are potent inhibitors of an antitumor immune response. The purpose of the study was to identify a CD4+ population of regulatory T cells expressing high levels of CD25(CD4+CD25 high) in the peripheral blood of cancer patients and provide the opportunity to determine whether cancer patients exhibit an expanded CD4+CD25high pool. METHODS: The frequency of CD4+CD25high in the peripheral blood of 62 cancer patients and 15 healthy donors was determined by flow cytometry. RESULTS: Compared with healthy donors, cancer patients have an increasing prevalence of CD4+CD25high T cells in the peripheral blood with characteristics of Tregs, i.e. they are CD45-RA(), CD69(-). Among patients, those with higher percentages of CD4+CD25high T cells had a poor prognosis than did those with lower percentages. CONCLUSION: We provide evidence of an increased pool of CD4+CD25high in the peripheral blood of cancer patients, which may be related to immunosuppression and tumor progress in cancer patients. This finding suggests that the use of immunomodulatory therapy to treat cancer patients may be an effective strategy.

[Correlation between FoxP3(+) regulatory T cells and chronic obstructive pulmonary disease].

OBJECTIVE: To investigate whether FoxP3(+) regulatory T cells (Treg) are present in the acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and the correlation between Treg and COPD. METHODS: Peripheral blood samples were collected from 21 patients of AECOPD, 20 males and 1 female, aged (70 +/- 9) (52-85). Lymphocytes were isolated by three-color labeled three colors monoclonal antibodies flow cytometry to examine the quantities and percentages of CD4(+)CD25(+), CD4(+)CD25(+)FoxP3(+) (CD4(+)Treg), CD8(+)CD25(+), and CD8(+)CD25(+)FoxP3(+) (CD8(+)Treg). ELISA was used to detect the expression of transforming growth factor beta1 (TGF-beta1), interleukin-10 (IL-10), and tumor necrosis factor alpha (TNF-alpha). Middle correlation coefficient r> or = 0.3 was analysed and discussed. RESULTS: The percentages of CD4(+)CD25(+), CD4(+)Treg, CD8(+)CD25(+), and CD8(+)Treg in AECOPD were (18 +/- 6)%, (19 +/- 13)%, (5 +/- 4)%, and (12 +/- 10)% respectively. Linear correlation analysis indicated that the quantity and percentage of Treg were significantly correlated with age, course of disease, smoking index, quantity of white cells, and blood pH, and there were complex causal relations between the immunity of patients and these factors. However, TGF-beta1 and IL-10 showed no correlation with Treg. CONCLUSION: CD4(+)Treg and CD8(+)Treg are expressed in the peripheral blood of AECOPD patients and contribute to the immune suppression of these patients, so they can be used as new markers of immunity of these patients.

Expression and functional role of HERG1, K+ channels in leukemic cells and leukemic stem cells.

In order to investigate the expression and functional role of HERG1 K+ channels in leukemic cells and leukemic stem cells (LSCs), RT-PCR was used to detect the HERG1 K+ channels expression in leukemic cells and LSCs. The functional role of HERG1 K+ channels in leukemic cell proliferation was measured by MTT assay, and cell cycle and apoptosis were analyzed by flow cytometry. The results showed that herg mRNA was expressed in CD34+/CD38-, CD123+ LSCs but not in circulating CD34+ cells. Herg mRNA was also up-regulated in leukemia cell lines K562 and HL60 as well as almost all the primary leukemic cells while not in normal peripheral blood mononuclear cells (PBMNCs) and the expression of herg mRNA was not associated with the clinical and cytogenetic features of leukemia. In addition, leukemic cell proliferation was dramatically inhibited by HERG K+ channel special inhibitor E-4031. Moreover, E-4031 suppressed the cell growth by inducing a specific block at the G1/S transition phase of the cell cycle but had no effect on apoptosis in leukemic cells. The results suggested that HERG1 K+ channels could regulate leukemic cells proliferation and were necessary for leukemic cells to proceed with the cell cycle. HERG1 K+ channels may also have oncogenic potential and may be a biomarker for diagnosis of leukemia and a novel potential pharmacological target for leukemia therapy.

[Role of MG132, a proteasome inhibitor, in inducing expression of costimulatory molecules CD86 in leukemic cells and its effect on allogeneic mixed lymphocyte reaction].

OBJECTIVE: To investigate the role of proteasome inhibitors MG132 in the inducing the expression of the costimulatory molecules CD80 and CD86 in leukemia cells and its effect on allogeneic mixed lymphocyte reaction. METHODS: Acute myelocytic leukemia cells of the line HL-60 and chronic myelocytic leukemia cells of the line K562 were cultured. 7-AAD staining and flow cytometry (FC) were used to examine the viability of the cells. MG132, a proteasome inhibitor, of the concentrations of 2 or 3 micromol/L was added into the culture fluid of HL-60 cells for 24 h and 48 h respectively and then annexin V/7-AAD staining and FC were used to detect the apoptosis of the cells. HL-60 and K562 cells treated with 1 micromol/L MG132 for 24 h and 48 h respectively, anti-CD80 and anti-CD86 antibodies were added, then FC was used to detect the expression of CD80 and CD86. The mRNA expression of CD86 in the HL-60 cells treated with 1 micromol/L MG132 was examined by RT-PCR. HL-60 and K562 cells were treated by 1 micromol/L MG132 for 48 h and then underwent irradiation of 75 Gy Co-60 to kill the cells with their antigenicity preserved. Peripheral blood mononuclear cells (PBMNC) of healthy volunteers, as reactive cells, were isolated and inoculated into the Co-60 treated HL-60 and K532 cells of different concentrations, as stimulating cells, for 5 d, CCK-8, a new agent to detect the cell viability, was added for 4 h, and then the A value of absorbance was measured at the wave length of 450 nm of enzyme labeling instrument. Control groups were set up for all tests. RESULTS: The cell viability rates of the HL-60 cell treated with 1 micromol/L MG132 for 24 h and 48 h were 92.95% and 85.87% respectively. The apoptotic rats of the HL-60 cells treated with MG132 were increased dose- and time-dependently. Before MG132 treatment K562 cells did not express CD86, and the CD86 expression of the HL-60 cells was up-regulated time-dependently (all P < 0.01). The mRNA expression of CD86 in the HL-60 treated with MG132 was up-regulated time-dependently (P < 0.01). CKK8 test showed that the proliferation level of PBMNC gradually increased along with the concentration of HL-60 cells treated with MG132 and reached its peak when the concentration of the HL-60 cells was 1 x 10(5) (P < 0.01). No remarkable proliferation of PBMNC was seen in the K562 groups no matter if the HL-60 cells had been treated with MG132. CONCLUSION: MG132 induces the expression of costimulatory molecule CD86 in the HL-60 cells, thus improving the proliferation of PBMNC.

Effects of adenovirus mediated vascular endothelial growth factor gene transfer on reconstitution of hematopoiesis in post-bone marrow transplantation mice.

BACKGROUND: Bone marrow transplantation (BMT) conditioning procedure is considered as the cause of damage to bone marrow microvasculature and the delay of hematopoiesis recovery. However, hematopoiesis regulation post BMT by vascular endothelial growth factor (VEGF) has not yet been studied. In this study, adenovirus were used to investigate the effects of VEGF gene transfer on preventing damages to bone marrow microenvironment and its promotion of hematopoiesis in post-BMT mice. METHODS: Recombinant adenovirus (Ad)-enhanced green fluorescent protein (EGFP)/hVEGF165 was injected via tail vein into BALB/c mice undergoing syngeneic BMT. During the different phases post BMT, the distribution of adenovirus and the plasma levels of hVEGF were measured as well as the numbers of white blood cells (WBC), platelet (PLT) and red blood cells (RBC) in peripheral blood. At the same time, the mice were injected with Chinese ink via tail vein, following which the tibias were separated and were used for analysis of bone marrow microvasculature surface area and cellularity. RESULTS: Significant expression of EGFP and hVEGF was observed in multiple organs at different phases post BMT, and the plasma level of hVEGF was up to (866.67 +/- 97.13) pg/ml. The recovery of WBC, PLT and RBC of the group treated with recombinant adenovirus Ad-EGFP/hVEGF165 were significantly more rapid than those of other BMT groups (P < 0.05, respectively). At the 20th day post BMT, the percentage of bone marrow microvasculature surface area in group treated with VEGF [(61.2 +/- 4.0)%] returned to normal level [(62.0 +/- 5.0)%, P > 0.05]. The restoration of hematopoiesis was retarded more than that of microvasculature. The cellularity of bone marrow in each group was still lower than that of normal control [(62.3 +/- 4.0)%, P < 0.05] at the 30th day post BMT, but the percentage in group treated with VEGF at the 20th and 30th days post BMT [(46.5 +/- 5.0)% and (55.1 +/- 4.5)%] exceeded those of other BMT groups (P < 0.05, respectively). CONCLUSION: VEGF gene transfer mediated by adenovirus may protect the hematopoietic microenvironment to promote the restoration of hematopoiesis in post-BMT mice.

[Growth properties of hematopoietic stem/progenitor cells in the second or third trimester and term fetal cord blood].

OBJECTIVE: To investigate the growth properties of hematopoietic progenitor/stem cells in umbilical cord blood (CB) of second trimester, third trimester, and term fetuses. METHODS: Blood was collected by umbilical cord puncture in 27 just delivered fetuses, including 16 term babies and 11 preterm fetuses. Mononuclear cells were isolated. CD34(+) cells were enriched and isolated using the MACS. The frequencies of CD34(+), CD34(+) CD38(-) and CD34(+) HLA-DR(+) cells were determined by fluorescence-activated cell sorting. The proliferative and self-renewal capacity and expansion response to varying concentrations of defined growth factors were determined by short or long-term liquid culture and methylcellulose self-solid culture. RESULTS: The frequency of CD34(+) and CD34(+) CD38(-) cells in CB and the frequency of CD34(+) CD38(-), CD34(+) HLA-DR(+) cells among CB CD34(+) cells were significantly higher in preterm CB than in term CB (3.14% and 0.76% vs 0.78% and 0.18%; and 9.8% and 20.4% vs 3.9% And 14.6%; P < 0.001). The number of colony forming units (CFUs) in preterm CB was higher and was correlated with the content of CD34(+) cells (r = 0.83). The number of long-term culture initiating cells (LTC-IC) in preterm CB was about 3 times as much as in term CB (5.7 +/- 1.2/10(5) cells vs 1.7 +/- 0.8/10(5) cells, P < 0.05), Progenitors from preterm CB could be expanded in short-term liquid cultures supplemented with hematopoietic growth factors as efficiently as progenitors from term CB, the peaks of expansion in terms of CFU, CD34(+) cells and CD34(+) CD38(-) cells were all at day 7, in particular under the condition of combining the early-acting and late-acting growth factors together (SCF + FL + TPO + IL-3 + IL-6). CONCLUSION: The frequency of hematoietic stem/progenitor cell in umbilical cord blood of preterm fetus (especially of mid-term fetus) is significantly higher than in CB of term babies. The hematoietic stem/progenitor cells in umbilical cord blood of preterm fetus have greater colony forming capacity, are sensitive to growth factors, effectively expand and proliferate in vitro, and are preferable target cells for gene therapy.

Infusions of recipient-derived cytokine-induced killer cells of donor origin eradicated residual disease in a relapsed leukemia patient after allo-hematopoietic stem cell transplantation.

A female patient diagnosed with acute myelocytic leukemia M5a (AML-M5a) relapsed 986 days after her allogeneic peripheral blood stem cell transplantation (allo-PBSCT) from an unrelated male donor with matched human leukocyte antigen (HLA). Three re-induction chemotherapies were administered, and partial remission was achieved. The patient was given repetitive infusion of cytokine-induced killer (CIK) cells expanded from recipient peripheral mononuclear cells of full donor chimerism due to loss of contact of quondam donor for donor lymphocyte infusion (DLI) and rejection of second transplantation. The patient achieved complete cytogenetical remission. This strategy might overcome the obstacle of donor unavailability and present an appealing new therapeutic alternative to donor-recruited adoptive immunotherapy for relapsed disease at post-transplantation.

[Influence of PP2A activator on proliferation of HL-60 cells and analysis of PP2A activity changes in patients with acute myeloid leukemia].

In order to investigate the effect of PP2A activator and PP2A inhibitor on proliferation of HL-60 cells and analyze the changes of PP2A activity in patients with acute myeloid leukemia (AML), HL-60 cells were treated with FTY720 alone or in combination with okadaic acid (OA) for 24 hours in culture. Cell proliferation was assayed with CCK8 kit. In addition, 20 AML patients including de novo AML and relapsed AML were enrolled in this study. The activity of PP2A in the peripheral blood mononuclear cells of patients was assayed with a PP2A Immunoprecipitation Phosphatase Assay Kit, the data were analyzed by software SPSS 16.0. The results indicated that as compared with control group, the proliferation of cells in FTY720 group was obviously inhibited (p < 0.05). The proliferation of cells in FTY720 + OA group was slightly inhibited as compared with the control group, there was no statistical difference (p > 0.05), but there was significant difference between the FTY720 + OA and FTY720 groups (p < 0.05). The activity of PP2A in AML patients (453.67 ± 102.52 pmol phosphate) was obviously lower than that in the normal controls (673.29 ± 96.32 pmol phosphate), there was significant difference between them (p < 0.01). It is concluded that the activation or inhibition of PP2A can affect the proliferation of HL-60 cells in vitro. Compared with healthy individuals, the activity of PP2A in AML patients is obviously lower. PP2A protein playing a key role in the occurrence and development of AML may be valuable for the diagnosis and treatment of AML.

[Influence of BCR-ABL inhibitor STI571 on SARI expression in K562 cells].

In order to investigate the molecular mechanisms of SARI expression regulation in chronic myeloid leukemia (CML), 46 patients with CML and 40 healthy volunteers were recruited in this study. SARI expression in the peripheral blood mononuclear cells (PBMNC) of CML patients and healthy volunteers was assayed by using real-time quantitative PCR. K562 cells were in vitro incubated with the BCR-ABL inhibitor STI571 (imatinib) at 37°C and 5% CO2 for 24 hours, then SARI expression was detected by using real-time quantitative PCR. All experiments were repeated three times. The results showed that as compared with healthy volunteers, the expression of SARI mRNA in PBMNC of CML patients presented a lower level (p < 0.001). After exposure of K562 cells to STI571 (2.5 µmol/L) for 24 hours, the SARI expression was higher than that in K562 cells treated without STI571 (p < 0.001). It is concluded that the suppression of SARI expression is involved in CML pathogenesis, and BCR-ABL mediates the down-regulation of SARI mRNA expression in K562 cells. These findings suggest a new orientation for gene therapy in CML patients.

[Mechanism of cinnamic aldehyde-inducing apoptosis of chronic myeloid leukemic cells in vitro].

The aim of this study was to investigate the apoptosis-inducing effect of cinnamic aldehyde (CA) on chronic myeloid leukemic (CML) cells and its mechanism. K562 cells and primary bone marrow mononuclear cells (MNC) from patients with CML were treated by various concentrations of CA. Flow cytometry was employed to measure the apoptosis of K562 cells and primary CML bone marrow MNC. Western blot was used to determine the expression of C-MYC and the phosphorylation of CrkL in K562 cells, and real-time polymerase chain reaction (real-time PCR) was used to quantify the expression of BCR-ABL mRNA in K562 cells. The results indicated that CA induced the apoptosis of K562 cells in a time- and dose-dependent manner. CA induced apoptosis of CML MNC dose-dependently. CA inhibited the expression of BCR-ABL mRNA and C-MYC, reduced CrkL phosphorylation levels in K562 cells. It is concluded that CA induces apoptosis of CML cells in vitro. Down-regulation of the expression and function of BCR-ABL may be one of its most important anti-leukemia mechanisms.

[Dyskeratosis congenital: clinical features and genotype analysis in two Chinese patients].

OBJECTIVE: To analysis the clinic and genotype in two Chinese patients with Dyskeratosis congenita (DC). METHODS: The two patients were characterized by mucocutaneous abnormalities (abnormal nails, lacey reticular pigmentation, and oral leukoplakia), bone marrow failure. They were diagnosed with DC. DC genes were amplified by polymerase chain reaction (PCR), including DKC1, TERT, TERC, TINF2, NOP10, NHP2, then DNA sequencing was performed for abnormal exons. RESULTS: An abnormal peak was found in exon 6 of TINF2 gene of the two patients. DNA sequencing showed a 845G→A transition in TINF2 gene in the two patients. CONCLUSION: We should think about DC if the young patients with mucocutaneous abnormalities and marrow failure. TINF2 c.845G→A(R282H) does exist in the two patients. It is reported in China for the first time.

Comprehensive flow cytometry phenotype in acute leukemia at diagnosis and at relapse.

Multiparameter flow cytometry (MFC) plays a vital role in the detection of minimal residual disease (MRD) and diagnosis of relapse in acute leukemia. However, application of a limited panel of antibodies in MFC leads to high rates of false-negative and false-positive results. Thirteen patients with acute lymphoblastic leukemia (ALL) and 12 patients with acute myeloid leukemia (AML) were immunophenotyped by MFC at diagnosis and at relapse using a comprehensive panel of monoclonal antibodies (McAbs) to 27 antigens and CD45/SSC gating. In 23 of 25 patients (92.3%), changes in at least one of progenitor-associated, myeloid and lymphoid antigens between diagnosis and relapse were observed. Antigen changes were observed in 92 of 239 antigens (38.5%) expressed in 25 patients, in 49 of 117 antigens (41.9%) expressed in 13 ALL patients, and in 43 of 122 antigens (35.2%) expressed in 12 AML patients. Phenotypic changes were characterized by the expression of cross-lineage antigens. The intralineage change was observed in the majority of patients. However, myeloid lineage shift was identified by MFC in two patients with T-ALL. Multiple panels of three or more McAbs are likely to be required in the monitoring of MRD and diagnosis of relapse in acute leukemia by MFC.

[Methylation status of JunB and CDH13 gene promoter in CD34(+)CD38(-) chronic myelogenous leukemia cells].

Chronic myelogenous leukemia (CML) is a clonal myeloproliferative disease of transformed hematopoietic progenitor cells. The expressions of JunB and CDH13 (cadherin-13) gene as tumor suppressor gene were inactivated by promoter methylation in CML patients. This study was purposed to investigate the methylation difference of JunB and CDH13 gene promoter and the expression levels of JunB and CDH13 gene in CD34(+)CD38(-) cells in CML patients vs normal individuals. CD34(+)CD38(-) cells from 8 cases of CML and 5 normal individuals were selected by flow cytometry. The methylation status of JunB and CDH13 genes were detected by MS-PCR in selected CD34(+)CD38(-) cells. The expression levels of JunB and CDH13 gene was detected with real time polymerase chain reaction (RT-PCR). The results showed that no methylation of JunB and CDH13 gene was detected in CD34(+)CD38(-) cells of 5 normal individuals. Methylations of JunB and CDH13 promoter were found in 87.5% (7/8) and 50% (4/8) CML CD34(+)CD38(-) cells, percentages of which were significantly higher than those in normal individuals. The difference was statistically significant (p < 0.05). The relative expression levels of JunB and CDH13 mRNA in CD34(+)CD38(-) cells of CML patients were significantly lower than those in normal individuals (2(-DeltaDeltaCT) were 1/5.21 and 1/10.63 respectively). It is concluded that the high methylation of JunB and CDH13 gene promoter occurs in CD34(+)CD38(-) cells of CML patients, their mRNA expression level is significantly lower, thus the methylation of JunB and CDH13 gene promoter probably plays a role in the pathogenesis of CML and may have clinical significance in predicting prognosis of CML.

Bmi1 functions as an oncogene independent of Ink4A/Arf repression in hepatic carcinogenesis.

Bmi1 is a polycomb group proto-oncogene that has been implicated in multiple tumor types. However, its role in hepatocellular carcinoma (HCC) development has not been well studied. In this article, we report that Bmi1 is overexpressed in human HCC samples. When Bmi1 expression is knocked down in human HCC cell lines, it significantly inhibits cell proliferation and perturbs cell cycle regulation. To investigate the role of Bmi1 in promoting liver cancer development in vivo, we stably expressed Bmi1 and/or an activated form of Ras (RasV12) in mouse liver. We found that while Bmi1 or RasV12 alone is not sufficient to promote liver cancer development, coexpression of Bmi1 and RasV12 promotes HCC formation in mice. Tumors induced by Bmi1/RasV12 resemble human HCC by deregulation of genes involved in cell proliferation, apoptosis, and angiogenesis. Intriguingly, we found no evidence that Bmi1 regulates Ink4A/Arf expression in both in vitro and in vivo systems of liver tumor development. In summary, our study shows that Bmi1 can cooperate with other oncogenic signals to promote hepatic carcinogenesis in vivo. Yet Bmi1 functions independent of Ink4A/Arf repression in liver cancer development.