Impact of a novel prognostic model on allogeneic hematopoietic stem cell transplantation outcomes in patients with CMML.

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell malignancy, and allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curable treatment. The outcomes after transplant are influenced by both disease characteristics and patient comorbidities. To develop a novel prognostic model to predict the post-transplant survival of CMML patients, we identified risk factors by applying univariable and multivariable Cox proportional hazards regression to a derivation cohort. In multivariable analysis, advanced age (hazard ratio [HR] 3.583), leukocyte count (HR 3.499), anemia (HR 3.439), bone marrow blast cell count (HR 2.095), and no chronic graft versus host disease (cGVHD; HR 4.799) were independently associated with worse survival. A novel prognostic model termed ABLAG (Age, Blast, Leukocyte, Anemia, cGVHD) was developed and the points were assigned according to the regression equation. The patients were categorized into low risk (0-1), intermediate risk (2, 3), and high risk (4-6) three groups and the 3-year overall survival (OS) were 93.3% (95%CI, 61%-99%), 78.9% (95%CI, 60%-90%), and 51.6% (95%CI, 32%-68%; p < .001), respectively. In internal and external validation cohort, the area under the receiver operating characteristic (ROC) curves of the ABLAG model were 0.829 (95% CI, 0.776-0.902) and 0.749 (95% CI, 0.684-0.854). Compared with existing models designed for the nontransplant setting, calibration plots, and decision curve analysis showed that the ABLAG model revealed a high consistency between predicted and observed outcomes and patients could benefit from this model. In conclusion, combining disease and patient characteristic, the ABLAG model provides better survival stratification for CMML patients receiving allo-HSCT.

Shikonin induces glioma cell necroptosis in vitro by ROS overproduction and promoting RIP1/RIP3 necrosome formation.

Necroptosis is a type of programmed necrosis regulated by receptor interacting protein kinase 1 (RIP1) and RIP3. Necroptosis is found to be accompanied by an overproduction of reactive oxygen species (ROS), but the role of ROS in regulation of necroptosis remains elusive. In this study, we investigated how shikonin, a necroptosis inducer for cancer cells, regulated the signaling leading to necroptosis in glinoma cells in vitro. Treatment with shikonin (2-10 µmol/L) dose-dependently triggered necrosis and induced overproduction of intracellular ROS in rat C6 and human SHG-44, U87 and U251 glioma cell lines. Moreover, shikonin treatment dose-dependently upregulated the levels of RIP1 and RIP3 and reinforced their interaction in the glioma cells. Pretreatment with the specific RIP1 inhibitor Nec-1 (100 µmol/L) or the specific RIP3 inhibitor GSK-872 (5 µmol/L) not only prevented shikonin-induced glioma cell necrosis but also significantly mitigated the levels of intracellular ROS and mitochondrial superoxide. Mitigation of ROS with MnTBAP (40 µmol/L), which was a cleaner of mitochondrial superoxide, attenuated shikonin-induced glioma cell necrosis, whereas increasing ROS levels with rotenone, which improved the mitochondrial generation of superoxide, significantly augmented shikonin-caused glioma cell necrosis. Furthermore, pretreatment with MnTBAP prevented the shikonin-induced upregulation of RIP1 and RIP3 expression and their interaction while pretreatment with rotenone reinforced these effects. These findings suggest that ROS is not only an executioner of shikonin-induced glioma cell necrosis but also a regulator of RIP1 and RIP3 expression and necrosome assembly.

Platelet Doubling After First Decitabine Cycle Predicts Response and Survival of Myelodysplastic Syndrome Patients.

OBJECTIVE: Although the effect of decitabine on myelodysplastic syndrome (MDS) has been demonstrated, merely a proportion of patients respond to therapy, and no well-recognized predictors have been identified. This study was conducted to investigate the effectiveness of decitabine in real-world clinical practice, and determine the predictive factors of response and overall survival (OS) in MDS patients. METHODS: Clinical and pathological data were collected from 94 patients and analyzed. These patients were reclassified according to the 2016 World Health Organization classification criteria, and restratified by International Prognostic Scoring System prognostic scores. The response evaluation was performed according to the 2006 modified International Working Group response criteria. RESULTS: In this study, 62% of patients responded to decitabine. Among these patients, 15 patients (16%) obtained complete remission (CR), 15 patients (16%) obtained marrow CR with hematologic improvement (HI), 20 patients (21%) obtained marrow CR without HI, and 8 patients (9%) only obtained HI, and no patient botained partial remission. The OS of the responders was significantly longer than that of non-responders (67 months vs. 7 months, P<0.001). The OS in patients with and without platelet doubling was significantly different in both the low/intermediate and high/very high risk groups (P=0.0398 and P=0.0330). The multivariate analysis revealed that platelet doubling after the first decitabine cycle is an independent predictor of response and OS in MDS patients (P=0.002 and P=0.008). CONCLUSION: Decitabine is effective for treating MDS patients in real-world clinical practice. Furthermore, platelet doubling after the first decitabine cycle can be used as a predictor of response and survival in MDS patients.

Frontline Therapy Options for Adults With Newly Diagnosed Severe Aplastic Anemia: Intensive immunosuppressive Therapy Plus Eltrombopag or Matched Sibling Donor Hematopoietic Stem Cell Transplantation?

Severe aplastic anemia (SAA) is a life-threatening bone marrow failure disease. Allogeneic hematopoietic stem cell transplantation from a matched sibling donor (MSD-HSCT) and intensive immunosuppressive therapy (IST) are 2 major comparable treatments for SAA. As the addition of eltrombopag (EPAG) to standard IST therapy has greatly improved the survival prognosis of SAA, whether MSD-HSCT or IST/EPAG is the better choice has become a matter of debate. A study was performed involving 99 patients with newly diagnosed acquired SAA from 5 medical centers, including 48 MSD-HSCT cases and 51 IST/EPAG cases, which consisted of rabbit antithymocyte globulin or porcine-antilymphocyte globulin, cyclosporine plus eltrombopag. The results suggested that patients treated with MSD-HSCT or IST/EPAG had similar overall survival (OS) rates exceeding 95% (P = .97). However, the event-free survival rate (EFS) of IST/EPAG (71.0%) was significantly lower than that of MSD-HSCT (89.6%), P = .04. Subgroup analysis indicated that the OS of the MSD-HSCT group was superior to that of the IST/EPAG group (100% versus 85.7%, P = .04) among those with very severe aplastic anemia (VSAA). Both the complete response rate (CR) and overall response rate (OR) with MSD-HSCT were significantly higher than those with IST/EPAG (CR: 79.2% versus 15.7%, P < .001; OR: 97.9% versus 72.6%, P = .001). In conclusion, IST/EPAG or MSD-HSCT treatment achieves an equally high OS in SAA, but MSD-HSCT leads to a better OS in patients with VSAA and shows advantages in improving EFS and accelerating hematopoietic reconstruction in patients with SAA.

Negative regulation of cyclin D3 expression by transcription factor c-Ets1 in umbilical cord hematopoietic cells.

AIM: To investigate the role of transcription factor c-Ets1 in cyclin D3 expression and its effects on the proliferation of umbilical cord hematopoietic cells. METHODS: Cyclin D3 promoter deletion constructs were generated and transfected into CD34(+) cells. Dual luciferase reporter assays and TFSEARCH software were used to identify negative regulatory domains and to predict putative transcription factors involved in cyclin D3 downregulation. Expression of c-Ets1 in CD34(+) cells was detected using electrophoretic mobility shift and super shift assays. Point mutants of c-Ets1 binding sites were constructed. The wild-type c-Ets1 and the mutant promoter constructs were co-transfected into CD34(+) cells to determine the promoter activity. The impact of c-Ets1 expression on the proliferation of CD34(+) cells was assessed using MTT assay. RESULTS: Nine cyclin D3 promoter deletion constructs were generated. A negative regulatory domain containing c-Ets1 binding sites was identified between -439 bp and -362 bp. Transfection of the promoter deletion constructs containing mutant c-Ets1 binding sites enhanced cyclin D3 promoter activity. However, the opposite results were observed when CD34(+) cells were co-transfected with wildtype c-Ets1 and its promoter deletion constructs. The overexpression of c-Ets1 could suppress cyclin D3 mRNA and protein levels. In addition, it inhibits the proliferation of CD34(+) cells. CONCLUSION: c-Ets1 functions as a negative transcription factor, down-regulating the expression of cyclin D3, which leads to inhibition of CD34(+) cell proliferation.

Proteasome inhibitor MG-132 induces C6 glioma cell apoptosis via oxidative stress.

AIM: Proteasome inhibitors have been found to suppress glioma cell proliferation and induce apoptosis, but the mechanisms are not fully elucidated. In this study we investigated the mechanisms underlying the apoptosis induced by the proteasome inhibitor MG-132 in glioma cells. METHODS: C6 glioma cells were used. MTT assay was used to analyze cell proliferation. Proteasome activity was assayed using Succinyl-LLVY-AMC, and intracellular ROS level was evaluated with the redox-sensitive dye DCFH-DA. Apoptosis was detected using fluorescence and transmission electron microscopy as well as flow cytometry. The expression of apoptosis-related proteins was investigated using Western blot analysis. RESULTS: MG-132 inhibited C6 glioma cell proliferation in a time- and dose-dependent manner (the IC(50) value at 24 h was 18.5 µmol/L). MG-132 (18.5 µmol/L) suppressed the proteasome activity by about 70% at 3 h. It induced apoptosis via down-regulation of antiapoptotic proteins Bcl-2 and XIAP, up-regulation of pro-apoptotic protein Bax and caspase-3, and production of cleaved C-terminal 85 kDa PARP). It also caused a more than 5-fold increase of reactive oxygen species. Tiron (1 mmol/L) effectively blocked oxidative stress induced by MG-132 (18.5 µmol/L), attenuated proliferation inhibition and apoptosis in C6 glioma cells, and reversed the expression pattern of apoptosis-related proteins. CONCLUSION: MG-132 induced apoptosis of C6 glioma cells via the oxidative stress.

[Allogeneic Hematopoietic Stem Cell Transplantation for Paroxysmal Nocturnal Hemoglobinuria].

OBJECTIVE: To analyze the clinical efficacy and safety of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for paroxysmal nocturnal hemoglobinuria (PNH), and preliminarily explore the role of an improved post-transplantation cyclophosphamide (PTCy) based conditioning regimen in PNH patients receiving transplantation. METHODS: Clinical related data of PNH sufferers receiving allo-HSCT in Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology were collected, and hematopoietic reconstitution, chimerism, PNH cloning, graft-versus-host disease (GVHD), infection, and survival were analyzed. RESULTS: Totally five PNH patients receiving allo-HSCT were enrolled, including 1 case with classic PNH, 3 cases with aplastic anemia-PNH syndrome, 1 case with myelodysplastic syndrome, three of them (case 1-3) received the improved PTCy based conditioning regimen before HSCT. All sufferers engrafted successfully within 28 days, the median time of neutrophil and platelet engraftment was 11 days and 12 days, respectively, no patient occurred acute or chronic GVHD, after a median follow-up of 16 months, all recipients survived and completely eliminated PNH cloning. CONCLUSION: Allo-HSCT can completely clear PNH cloning and restore hematopoietic function with controllable complications, and the improved PTCy based conditioning regimen is proved to be effective in PNH transplantation.

Inhibition of autophagy induced by proteasome inhibition increases cell death in human SHG-44 glioma cells.

AIM: The ubiquitin-proteasome system (UPS) and lysosome-dependent macroautophagy (autophagy) are two major intracellular pathways for protein degradation. Recent studies suggest that proteasome inhibitors may reduce tumor growth and activate autophagy. Due to the dual roles of autophagy in tumor cell survival and death, the effect of autophagy on the destiny of glioma cells remains unclear. In this study, we sought to investigate whether inhibition of the proteasome can induce autophagy and the effects of autophagy on the fate of human SHG-44 glioma cells. METHODS: The proteasome inhibitor MG-132 was used to induce autophagy in SHG-44 glioma cells, and the effect of autophagy on the survival of SHG-44 glioma cells was investigated using an autophagy inhibitor 3-MA. Cell viability was measured by MTT assay. Apoptosis and cell cycle were detected by flow cytometry. The expression of autophagy related proteins was determined by Western blot. RESULTS: MG-132 inhibited cell proliferation, induced cell death and cell cycle arrest at G(2)/M phase, and activated autophagy in SHG-44 glioma cells. The expression of autophagy-related Beclin-1 and LC3-I was significantly up-regulated and part of LC3-I was converted into LC3-II. However, when SHG-44 glioma cells were co-treated with MG-132 and 3-MA, the cells became less viable, but cell death and cell numbers at G(2)/M phase increased. Moreover, the accumulation of acidic vesicular organelles was decreased, the expression of Beclin-1 and LC3 was significantly down-regulated and the conversion of LC3-II from LC3-I was also inhibited. CONCLUSION: Inhibition of the proteasome can induce autophagy in human SHG-44 glioma cells, and inhibition of autophagy increases cell death. This discovery may shed new light on the effect of autophagy on modulating the fate of SHG-44 glioma cells.Acta Pharmacologica Sinica (2009) 30: 1046-1052; doi: 10.1038/aps.2009.71.

NKILA inhibits NF-κB signaling and suppresses tumor metastasis.

The long non-coding RNA (lncRNA) NKILA (nuclear transcription factor NF-κB interacting lncRNA) functions as a suppressor in human breast cancer and tongue cancer. However, the clinical significance and biological roles of NKILA in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we showed that NKILA was downregulated in ESCC tissues and cancer cells compared with their normal counterparts. Low NKILA expression correlated with large tumor size and advanced TNM stage, and predicted poor overall and disease-free survival of ESCC patients. Further loss- and gain-of-function assays indicated that NKILA inhibited proliferation and migration of ESCC cells in vitro, suppressed tumor growth and lung metastasis in vivo. Mechanistically, NKILA could inhibit phosphorylation of IκBα, suppress p65 nuclear translocation and downregulate the expression of NF-κB target genes in ESCC cells. These results suggest NKILA could suppress malignant development of ESCC via abrogation of the NF-κB signaling and may potentially serve as a prognostic marker for ESCC.

CiRS-7 promotes growth and metastasis of esophageal squamous cell carcinoma via regulation of miR-7/HOXB13.

The circular RNA ciRS-7 has been reported to be involved in the pathogenesis of various tumors, including gastric and colorectal cancer. However, the role of ciRS-7 in esophageal squamous cell carcinoma (ESCC) remains unsolved. In this study, we found that the ciRS-7 expression was significantly upregulated in ESCC cancer tissues compared with matched normal tissues and associated with poor patient survival. Overexpression of ciRS-7 abrogated the tumor-suppressive roles of miR-7 including cell proliferation, migration and invasion in vitro as well as tumor growth and lung metastasis in vivo. Mechanistically, ciRS-7 functioned as the sponge of miR-7 and reactivated its downstream HOXB13-mediated NF-κB/p65 pathway. Conclusively, our findings demonstrate how ciRS-7 induces malignant progression of ESCC and that ciRS-7 may act as a novel prognostic marker and therapeutic target for this lethal disease.

MicroRNA-192 regulates cell proliferation and cell cycle transition in acute myeloid leukemia via interaction with CCNT2.

MicroRNAs (miRNAs) are a class of small non-coding RNAs approximately 18-22 nucleotides in length, which play an important role in malignant transformation. The roles of miR-192 as an oncogene or tumor suppressor in solid tumors have been previously reported. However, little is known about the role of miR-192 in human acute myeloid leukemia. The results of the present study indicate that miR-192 is significantly downregulated in specimens from acute myeloid leukemia patients. Functional assays demonstrated that overexpression of miR-192 in NB4 and HL-60 cells significantly inhibited cell proliferation compared with that in control cells, and induced G0/G1 cell cycle arrest, cell differentiation, and apoptosis in vitro. Dual-luciferase reporter gene assays showed that miR-192 significantly suppressed the activity of a reporter gene containing the wild type 3'-UTR of CCNT2, but it did not suppress the activity of a reporter gene containing mutated 3'-UTR of CCNT2. QRT-PCR and Western blot assays showed that miR-192 significantly downregulated the expression of CCNT2 in human leukemia cells. Exogenous expression of CCNT2 attenuated the cell cycle arrest induced by miR-192 in NB4 and HL-60 cells. Collectively, miR-192 inhibits cell proliferation and induces G0/G1 cell cycle arrest in AML by regulating the expression of CCNT2.

[Gene mutation and myelodysplastic syndromes with ring sideroblast excess].

Myelodysplastic syndromes (MDS) are heterogeneous clonal hematopoietic stem cell disorders with different mechanisms and diverse prognosis. The excess of ring sideroblasts (RS) is an important presentation MDS, but the mechanisms of RS appearance are obscure and the treatment of MDS-RS is intractable. Splicing factors play a very important role in the maturation process of eucaryon mRNA, recent studies indicate that there is a significant causal relationship between splicing factor 3B subunit 1 (SF3B1) mutation and the presence of ring sideroblasts. Lucubrating the downstream molecular of the mutated SF3B1 can facilitate exploring the mechanisms and new therapeutic strategies of MDS-RS.

[The correlation between early lymphocyte count post-allogeneic hematopoietic stem cell transplantation and prognosis in leukemia patients].

OBJECTIVE: To analyze the correlation between early lymphocyte count (lymphocyte count on day 30, LC30) post-allogeneic hematopoietic stem cell transplantation (allo-HSCT) and transplant prognosis in leukemia patients. METHODS: The data from 124 consecutive patients undergoing allo-HSCT for leukemia from January 2003 to April 2011 was analyzed retrospectively. LC30 post-allo-HSCT correlated with 5-year overall survival (OS), 5-year relapse rate (RR), 5-year nonrelapse mortality (NRM), accumulative rate of acute graft versus host disease (aGVHD) and chronic graft versus host disease (cGVHD) was studied. RESULTS: Univariate analysis indicated that patients with LC30 ≥ 0.40×10(9)/L had higher 5-year OS than those with LC30 < 0.40×10(9)/L \[(62.2 ± 5.8)% vs (37.0 ± 8.6)%, P = 0.003\], lower 5-year RR\[(13.9 ± 4.7)% vs (32.0 ± 8.4)%, P = 0.027\], lower 5-year NRM \[(31.3 ± 5.8)% vs (45.0 ± 9.3)%, P = 0.048)\], and higher cGVHD cumulative incidence \[(82.9 ± 4.6)% vs (62.7 ± 11.1)%, P = 0.042)\]. Multivariate analysis also suggested that LC30 was associated with 5-year OS, 5-year RR, 5-year NRM, and cGVHD cumulative incidence. At the same time disease risk stratification was associated with prognosis. CONCLUSIONS: Early lymphocyte count (LC30) post-allogeneic hematopoietic stem cell transplantation in leukemia is highly associated with prognosis, which can be the independent prognosis index after allo-HSCT in leukemia and can identify a group of patients who might be suitable candidates for early interventions treatment.

[Aberrant methylation at promoter region of HOX A gene cluster in leukemia cells].

OBJECTIVE: To explore the characteristics of CpG islands methylation at promoter region of HOX A gene cluster in leukemia cells before and after all-trans retinoic acid (ATRA) treatment. METHODS: Eleven human leukemia cell lines, bone marrow cells from leukemia patients before and after therapy and white blood cells from normal subjects were collected. HL-60 and K562 cells were treated by 2-deoxy-5-azacytidine (DAC) or ATRA respectively. Bisulfite modified DNA of these cells were amplified with PCR and quantitatively analyzed by pyrosequencing for methylation of CpG islands. RESULTS: In normal cells, CpGs at all loci of HOX A cluster were unmethylated. In HOX A4, A6, A7, A9, A10 and A11, many CpG sites were methylated (>20%) or hypermethylated (>50%) in leukemia cell lines. Percentages of methylated CpGs were higher in T-cell leukemia (71.4%) and B-cell leukemia (85.7%) than in others. For individual CpGs methylations there were HOX A4 in all leukemia cells, HOX A6 and HOX A7 in most of the leukemia samples and HOX A10 and HOX A11 in K562 and HL-60 cells (38%-86%). HOX A9 CpGs showed hypomethylation in most of myeloid leukemia cells, whereas HOX A11 CpGs were hypermethylated in B-cell leukemia (>50%). Methylation levels of HOX A4 and A6 in AML and ALL patients after complete remission were decreased obviously, and so did HOX A6 and A9 in CML patients. Methylation levels of HOX A4, A6 and A10 in HL-60 cells and of HOX A6 in K562 cells were reduced by ATRA treatment. CONCLUSIONS: In all leukemia cell lines, aberrant methylation of CpGs was observed at promoter regions of 6 HOX A cluster genes, and some of these genes showed leukemia-type-specific hypermethylation. CpGs methylation of some HOX A genes in leukemia cell lines, especially in HL-60 cells, were down-regulated by ATRA.

[Diagnostic role of BIOMED-2 multiplex polymerase chain reaction for antigen receptor genes rearrangement in lymphoproliferative disorders].

OBJECTIVE: To establish a sensitive and effective method for detection of immunoglobulin and T-cell receptor (Ig/TCR) gene rearrangement,and to explore its role in diagnosis and differential diagnosis of lymphoproliferative disorders. METHODS: Fifty-eight lymphoid tissue samples from 54 patients with lymphoproliferations were evaluated by the novel BIOMED-2 multiplex polymerase chain reaction (PCR) for antigen receptor genes rearrangement. RESULTS: Multiplex PCR demonstrated monoclonal Ig/TCR gene rearrangements in 22 of 25 (88.0%) B-cell malignancies and 8 of 15 (53.3%) T-cell malignancies. Among 17 benign lymphoproliferations confirmed histopathologically, polyclonal rearrangements were detected in 14 cases (82.4%). In total, the clonality analysis and the final clinico-histopathological diagnosis were concordant in 77.2%. Combination detection of Iglambda and TCR delta gene rearrangements did not increase the detection rate of monoclonal rearrangement of Ig/TCR, but might help to the detection of Iglambda+ or TCR delta+ lymphomas. CONCLUSION: The novel BIOMED-2 multiplex PCR strategy is a rapid, reliable and sensitive approach to detecting clonality in suspected lymphoproliferations, especially in atypical cases.

[Effects of ligustrazine on expression of VCAM-1/VLA-4 in syngenic bone marrow transplantation of mice].

To explore the effect of ligustrazine on the expression of adherent molecule VCAM-1/VLA-4 of bone marrow cells in syngenic bone marrow transplantation (BMT) mice, the mice were divided into 3 groups: normal group (which received no treatment), BMT control group and ligustrazine-treated groups. BMT mouse models were established. The BMT control group and the ligustrazine-treated group were orally administered 0.2 ml saline per mouse and 2 mg ligustrazine per mouse, respectively, twice a day. On the day 7, 14, 21, 28 after BMT, mice were respectively killed. Bone marrow nucleated cells were detected, and then the expression of VCAM-1/VLA-4 was assayed by immunohistochemistry, RT-PCR and flow cytometry analysis, respectively. The results showed that in ligustrazine-treated group, the accounts of bone marrow nucleated cells on the day 7, 14, 21, 28 after BMT were all higher than that in BMT control group. The expression level in the ligustrazine-treated group was significantly higher than that in the BMT control group (P < 0.05 or P < 0.01). It is concluded that ligustrazine can enhance VCAM-1/VLA-4 expression in bone marrow after syngenic bone marrow transplantation in mice, which may be related to the mechanisms underlying the ligustrazine accelerating hematopoietic reconstitution in allogenic bone marrow transplantation.

[To inhibit ERK for enhancing chemotherapy sensitivity of drug-resistance cell lines of leukemia and ovarian carcinoma].

The aim was to study the roles of extracellular regulated protein kinases (ERK) and telomerase activity in drug resistance of human leukemia and ovarian carcinoma cells. Flow cytometry was used to analyze apoptosis rate. Telomere repeat amplification protocol (TRAP) and bioluminescence analysis method were used for detection of telomerase activity. The phosphorylated ERK(1/2) protein expression was observed by Western blot method. The results showed that the specific inhibitor PD98059 of ERK kinase 1 (MEK(1)) enhanced the sensitivity of HL-60/E6 leukemia cell lines to harringtonine (HRT) or COC1/DDP ovarian carcinoma cell lines to cis-dichlorodiamine platinum (DDP). Both PD98059 and chemotherapy drugs HRT and DDP reduced the phosphorylated ERK(1) and ERK(2) protein expression level, and down-regulated the telomerase activity. The sole action of each was inferior to the combination action of PD98059 and HRT or DDP. In conclusion, ERK and telomerase serve a function to some extent in drug resistance of leukemia and ovarian carcinoma cells. The inhibition of ERK signal transduction pathways led to reduction of phosphorylated ERK(1) and ERK(2) protein expression level, and successionally down-regulated the telomerase activity. The final result was to enhance the sensitivity of HL-60/E6 to HRT or COC1/DDP to DDP.

Regulative function of extracellular regulated protein kinases and telomerase in apoptosis of hepatocarcinomatous and leukemic cell lines.

In order to investigate the change of telomerase activity and phosphorylated (activated) extracellular regulated protein kinases (ERK) 1 and 2 in hepatocarcinomatous cell line SMMC7721 and leukemic cell line K562 proliferation inhibition and apoptosis, three kinds of chemotherapeutic drugs harringtonine (HRT), vincristine (VCR) and etoposide (VP-16) were selected as inducers; and MTT assay, flow cytometry analysis, telomeric repeat amplification protocol (TRAP) assay and bioluminescence analysis were used. The results showed that after treatment of HRT, VCR and VP-16 for 24 hours, the cell proliferation was inhibited, apoptosis was induced, and telomerase activity and the protein expression of phosphorylated ERK1/2 were down-regulated. In HRT treated groups, the descendent grade was the most obvious. It was concluded that the common molecular mechanism of these chemotherapeutic drugs killing SMMC7721 and K562 cell lines might be through inhibiting ERK signal transduction pathways, cutting down ERK activity, reducing the transcription of target genes of ERKs, then indirectly down-regulate telomerase activity, and cell apoptosis is the final result of durative loss of telomere.

[Effects of ligustrazine on expression of PECAM-1/CD31 and hematopoietic reconstitution in syngenic bone marrow transplantation of mice].

To estimate the effect of ligustrazine on the expression of PECAM-1/CD31 and hematopoietic reconstitution in syngenic bone marrow transplanted mice, 56 BALB/c mice were divided into 3 groups: normal control group, BMT control group, ligustrazine treated group (BMT + Ligustrazine) and syngenic BMT mouse models were established according to the literatures. The BMT control group and the ligustrazine treated group were given orally 0.2 ml saline and 2 mg ligustrazine twice a day respectively. On days 7, 14, 21 after BMT, mice were killed and peripheral blood cells, bone marrow nucleated cells (BMNC) were detected. Histological observation of bone marrow was made and the CD31 expression was assayed by flow cytometry. The results showed that in ligustrazine treated group the peripheral blood cell, BMNC counts on days 7, 14, 21 after BMT were higher than in the BMT control group (P < 0.01 or P < 0.05). The expression of CD31 in ligustrazine treated group on days 7, 14, 21 after BMT was also higher than in the BMT control group (P < 0.01 or P < 0.05). In conclusion, ligustrazine enhances CD31 expression in bone marrow cells after syngenic bone marrow transplantation of mice, which may be related to the mechanisms underlying the ligustrazine accelerating hematopoietic reconstitution in syngeneic bone marrow transplantation.

The effects of interferon-gamma on the expression of the cyclin D isoforms in cord blood hematopoietic stem/progenitor cells.

To explore the hematopoiesis inhibition mechanisms of interferon-gamma (IFN-gamma), the effects of IFN-gamma on the expression of the cyclin D in the umbilical cord blood hematopoietic stem/progenitor cells were observed. In the experiments the CD34(+) cells were isolated from the cord blood with MIDI-MACS system; semi-solid methylcellulose culture technique was used to measure the formation of CFU-GM; the expression levels of cyclin D isoforms were assayed by semi-quantitative RT-PCR, after the hematopoietic stem/progenitor cells were incubated with IFN-gamma. The results indicated that IFN-gamma could inhibit the formation of CFU-GM and down-regulate the expression of cyclin D2 and cyclin D3 at the mRNA level. It is concluded that the IFN-gamma could inhibit the proliferation of hematopoietic stem cells and down-regulate the expression of cyclin D, that may be one mechanism underlying the hematopoietic inhibition of IFN-gamma.