Blood coagulation factor VIII D1241E polymorphism leads to a weak malectin interaction and reduction of factor VIII posttranslational modification and secretion.

Blood coagulation factor VIII (FVIII) is a key cofactor in regulation of blood coagulation. This study investigated the mechanism by which FVIII is translated and transported into the endoplasmic reticulum (ER) and processed in the Golgi apparatus before secretion using an in vitro cell model. HEK-293T cells were transfected with vectors carrying wild-type (WT) FVIII or polymorphic FVIII D1241E for coexpression with ER lectins and treatment with tunicamycin (an N-linked glycosylation inhibitor), 1-deoxynojirimycin (an alpha-glucosidase inhibitor), endoglycosidase H, or MG132 (Cbz-Leu-Leu-leucinal; a proteasome inhibitor). The data showed that the minor allele of FVIII D1241E was able to reduce FVIII secretion into the conditioned medium but maintain a normal level of procoagulation ability, although both FVIII WT and the minor allele of FVIII D1241E showed similar levels of transcription and translation capacities. Functionally, the D1241E polymorphism led to a reduced level of FVIII in the Golgi apparatus because of its reduced association with malectin, which interacts with newly synthesized glycoproteins in the ER for FVIII folding and trafficking, leading to degradation of the minor allele of FVIII D1241E in the cytosol. This study demonstrated that malectin is important for regulation of the FVIII posttranslational process and that the minor allele of FVIII D1241E had a reduced association with malectin but an increased capacity for proteasomal FVIII degradation. These data imply the role of the ER quality control in future recombinant FVIII development.

R-spondin1/Wnt-enhanced Ascl2 autoregulation controls the self-renewal of colorectal cancer progenitor cells.

The Wnt signaling pathway controls stem cell identity in the intestinal epithelium and cancer stem cells (CSCs). The transcription factor Ascl2 (Wnt target gene) is fate decider of intestinal cryptic stem cells and colon cancer stem cells. It is unclear how Wnt signaling is translated into Ascl2 expression and keeping the self-renewal of CRC progenitor cells. We showed that the exogenous Ascl2 in colorectal cancer (CRC) cells activated the endogenous Ascl2 expression via a direct autoactivatory loop, including Ascl2 binding to its own promoter and further transcriptional activation. Higher Ascl2 expression in human CRC cancerous tissues led to greater enrichment in Ascl2 immunoprecipitated DNA within the Ascl2 promoter in the CRC cancerous sample than the peri-cancerous mucosa. Ascl2 binding to its own promoter and inducing further transcriptional activation of the Ascl2 gene was predominant in the CD133+CD44+ CRC population. R-spondin1/Wnt activated Ascl2 expression dose-dependently in the CD133+CD44+ CRC population, but not in the CD133-CD44- CRC population, which was caused by differences in Ascl2 autoregulation under R-spondin1/Wnt activation. R-spondin1/Wnt treatment in the CD133+CD44+ or CRC CD133-CD44- populations exerted a different pattern of stemness maintenance, which was defined by alterations of the mRNA levels of stemness-associated genes, the protein expression levels (Bmi1, C-myc, Oct-4 and Nanog) and tumorsphere formation. The results indicated that Ascl2 autoregulation formed a transcriptional switch that was enhanced by Wnt signaling in the CD133+CD44+ CRC population, thus conferring their self-renewal.

[Efficacy of Shengxue Mixture Combined with Intraosseous Infusion for Treatment of Aplastic Anemia].

OBJECTIVE: To evaluate the efficacy and safety of Shengxue mixture combined with intraosseous blood infusion for treatment of aplastic anemia patients. METHODS: From 2011 to 2015, Institute of blood diseases of Shaanxi Medical University admitted 53 patients with aplastic anemia. The patients were treated with shengxue mixture 200 ml, orally, twice a day. Stanozolol tablets, Adult 2 mg, three times a day, mycophenolate mofetil 1.0 g, twice a day. Intraosseous infusion of the following medicine were administered in patients: recombinant human EPO 10000 U, recombinant human G-CSF 450 µg, recombinant human IL-11 4.5 mg, dexmethasone 20 mg, once a week, a total of four times. One month later, the blood cell counts and bone marrow biopsy were performed. Consolidation treatment continued for 3 to 6 months after discharge, and therapeutic effect was observed and followed-up for more than a year. RESULTS: After one month of treatment, 40 patients were basically cured (75.47%), 8 patients were remitted(15.09%), Hemoglobin level, white blood cell count and platelet count were significantly improved after treatment (P<0.01). The overall response rate was 90.57%(48 patients). Patients with bone marrow hyperplasia was 46 (86.79%), versus 9(16.98%) before treatment. There was a difference (P<0.05). After 3 to 6 months of treatment, 40 patients were cured (75.47%); 8 patients were remitted(15.09%); 3 patients were obviously improved(5.66%); 2 patients were ineffective(3.77%). The overall response rate was 96.23%(51 cases). No obvious side effects were observed. No patients were relapsed after one year. CONCLUSION: Shengxue mixture combined with Intraosseous infusion is a fast, efficient, safe method for the treatment of aplastic anemia.

HIF-1α/Ascl2/miR-200b regulatory feedback circuit modulated the epithelial-mesenchymal transition (EMT) in colorectal cancer cells.

We have reported that Achaete scute-like 2 (Ascl2) transcriptionally repressed miR-200 family members and affected the epithelial-mesenchymal transition (EMT)-mesenchymal-epithelial transition (MET) plasticity in colorectal cancer (CRC) cells. However, little is known about the regulation of the Ascl2/miR-200 axis. Here, we found that hypoxia inducible factor-1α (HIF-1α) mRNA levels were positively correlated with Ascl2 mRNA levels and inversely correlated with miR-200b in CRC samples. Mechanistically, we showed that Ascl2 was a downstream target of HIF-1α and had a critical role in the EMT phenotype induced by hypoxia or HIF-1α over-expression. Hypoxia or HIF-1α over-expression activated Ascl2 expression in CRC cells in a direct transcriptional mechanism via binding with the hypoxia-response element (HRE) at the proximal Ascl2 promoter. HIF-1α-induced Ascl2 expression repressed miR-200b expression to induce EMT occurrence. Furthermore, we found HIF-1α was a direct target of miR-200b. MiR-200b bound with the 3'-UTR of HIF-1α in CRC cells. HIF-1α/Ascl2/miR-200b regulatory feedback circuit modulated the EMT-MET plasticity of CRC cells. Our results confirmed a novel HIF-1α/Ascl2/miR-200b regulatory feedback circuit in modulating EMT-MET plasticity of CRC cells, which could serve as a possible therapeutic target.

Ascl2 activation by YAP1/KLF5 ensures the self-renewability of colon cancer progenitor cells.

Achaete scute-like 2 (Ascl2) is the Wnt signaling target, its regulation by other signaling is undefined. Now we demonstrated that CD133+/CD44+ cell population from HT-29 or Caco-2 cells exhibited cancer stem cell (CSC) properties with highly expressed Ascl2, which is related to the Hippo signaling pathway. YAP1 interference in CD133+/CD44+ HT-29 or Caco-2 cells reduced their proliferation, colony-forming ability and tumorsphere formation in vitro and inhibited the 'stemness'-associated genes and Ascl2 expression. Enforcing YAP1 expression in HT-29 or Caco-2 cells triggered the opposite changes. Ascl2 interference reversed the phenotype of YAP1-enforced expressed HT-29 or Caco-2 cells. Krüppel-like factor 5 (KLF5) protein, not KLF5 mRNA levels, were increased due to YAP1 overexpression which is reported to prevent KLF5 degradation. Co-immunoprecipitation (Co-IP) assays demonstrated that YAP1 bound with KLF5 in HT-29 and Caco-2 cells. Luciferase and chromatin immunoprecipitation (ChIP) assays indicated that both YAP1 and KLF5 bound to the first two loci with GC-boxes in Ascl2 promoter and induced Ascl2 transcription. The decreased Ascl2 transcription by YAP1 interference required an intact KLF5 binding site (GC-box) within Ascl2 promoter, KLF5 knockdown reduced YAP1 binding and Ascl2 luciferase reporter activity upon YAP1 overexpression. Positive correlation among YAP1 and Ascl2 mRNA levels was observed in colorectal cancer (CRC) samples. Thus, our study demonstrated that Ascl2, a fate decider of CRC progenitor cells can be activated by the Hippo signaling pathway in CRC progenitor cells, and ensured their self-renewability.

Realgar-induced apoptosis and differentiation in all-trans retinoic acid (ATRA)-sensitive NB4 and ATRA-resistant MR2 cells.

Realgar has been used in Western medicine and Chinese traditional medicine since ancient times, and its promising anticancer activity has attracted much attention in recent years, especially for acute promyelocytic leukemia (APL). However, the therapeutic action of realgar treatment for APL remains to be fully elucidated. Cellular cytotoxicity, proliferation, apoptosis and differentiation were comprehensively investigated in realgar-treated cell lines derived from PML-RARα+ APL patient, including the all-trans retinoic acid (ATRA)-sensitive NB4 and ATRA-resistant MR2 cell lines. For analysis of key regulators of apoptosis and differentiation, gene expression profiles were performed in NB4 cells. Realgar was found to induce apoptosis and differentiation in both cell lines, and these effects were exerted simultaneously. Gene expression profiles indicated that genes influenced by realgar treatment were involved in the modulation of signal transduction, translation, transcription, metabolism and the immune response. Given its low toxicity, realgar is a promising alternative reagent for the therapy of APL. Our data contribute to an understanding of the underlying mechanism responsible for the therapeutic effects of realgar in the clinical treatment of APL.

[Clinical study of combination of Chinese medicine and western medicine in treatment of 500 patients with hemophilia hemorrhage].

OBJECTIVE: To study the effect and safety of haemostatic apozem combined with haemostatic mixture on hemophilia hemorrhage. METHODS: Five hundred hemophilia patients were randomly recruited from Shaanxi Yida Hematology Institute from February 2005 to July 2010. Under the condition of using no blood products such as platelet cofactors VIII and IX, oral administration of haemostatic apozem combined with intravenous dripping of haemostatic mixture were given to 332 hemorrhagic patients and 451 patients in need of surgery for hemorrhagic prevention. The treatment was lasted for three successive weeks. The hemostatic time, hemorrhage absorption (recovery) time, and their safety were observed. RESULTS: The hemostatic time for open bleeding and closed bleeding was (0.85 +/- 0.83) h and (2.69 +/- 0.65) h respectively. The average hemostatic time was (2.00 +/- 0.69) h. The recovery time for different portions was as follows respectively: intra-cranial hemorrhage (14.13 +/- 6.01) days; muscular hemorrhage (18.18 +/- 7.34) days; hematuria (8.25 +/- 4.69) days; arthrorrhagia(3.27 +/- 1.31) days; ecchymoma (7.16 +/- 2.32) days; bleeding of oral and nasal cavities (4.26 +/- 1.35) days; intramedullary hemorrhage (19.15 +/- 1.36) days; hematoma ulceration (50.01 +/- 20.91) days. The hemorrhage recovery ratio was 99.10% (329/332). The success rate of preventing from surgery hemorrhage was 100% (451/451). No severe adverse reaction occurred during the therapeutic course. CONCLUSIONS: Haemostatic apozem combined with haemostatic mixture was effective and fast in preventing and treating hemophilia hemorrhage, with no complications or adverse reactions. It could be taken as the first choice for prevention and treatment of hemophilia hemorrhage.

Secretory expression of Par-4 SAC-HA2TAT following adeno-associated virus-mediated gene transfer induces apoptosis in HepG2 cells.

Prostate apoptosis response-4 (Par-4) is a tumor-suppressor protein that induces apoptosis in cancer cells, but not in normal cells. The cancer-specific pro-apoptotic action of Par-4 is encoded in its centrally located SAC domain. In this study, to further enhance the anti-cancer effect of Par-4 in order to overcome the limitations of peptide therapy, a recombinant adeno-associated virus was constructed using the following strategies: the secretory expression of therapeutic peptide, a HA2TAT-mediated cytosolic delivery technique, and an adeno-associated virus gene transfer system. To test the hypothesis that Par-4 has an additive bystander effect as an anti-cancer therapy, we designed a secretory protein by adding a secretory signal peptide NT4(Si) to the Par-4 SAC-HA2TAT peptide gene sequence [NT4(Si)-Par-4 SAC-HA2TAT]. The results indicated that, compared to the normal NIH3T3 cell line, AAV-NT4(Si)-Par-4 SAC-HA2TAT significantly suppressed cell growth and induced rapid cell death in HepG2 cells in a time-dependent manner through successful gene transfer and secretory expression of therapeutic peptide at 48 h post-transfection. In addition, the secretory properties of Par-4 may greatly increase its effectiveness in cancer therapy when delivered in vivo.

[Comparison of the effect of arsenic sulfide on apoptosis and hTERT-mRNA expression in two leukemia cell lines].

AIM: To explore the different effect and mechanism of arsenic sulfide on telomerase activity and hTERT-mRNA expression in CML cell lines-K562 and APL cell lines-NB4. METHODS: Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). The expression of hTERT-mRNA was analyzed by semi-quantitative RT-PCR. Flow cytometry was used to analyze the cell cycle and apoptosis. RESULTS: 0.15-0.6 mg/L arsenic sulfide (72 h)can induce apoptosis and inhibit telomerase activity and hTERT-mRNA expression in NB4 cell. The concentration of arsenic sulfide with the same effect on K562 cell was 0.3-3 mg/L. 0.3 mg/L arsenic sulfide (72 h) can cause the proportion of the NB4 cell in G2/M phase increased, but for K562 cell, The concentration of arsenic sulfide was 1.5 mg/L. CONCLUSION: Telomerase system may be one of the pathway for arsenic sulfide inducing apoptosis of NB4 and K562 cell; G2/M phrase arrest may have correlation with decrease of telomerase activity; The sensitivity of NB4 and K562 cell for arsenic sulfide is different, the mechanism of it need to study more.

[The effect of arsenic sulfide combined with IFN-alpha on K562 cells].

AIM: To study if the effect of arsenic sulfide combined with IFN-alpha can be increased on K562 cells. METHODS: Telomerase activity was determined by PCR-ELISA. Flow cytometry was used to analyze the cell apoptosis. The final concentration of IFN-alpha and arsenic sulfide was 10,000 U/mL and 0.6 mg/L. RESULTS: The rates of apoptosis was 37.8% and 37% in K562 cells treated with IFN-alpha or arsenic sulfide alone for 8 days; The rates of apoptosis and inhibition of telomerase activity was 59.9% and 81.2% in K562 cells treated with IFN-alpha and arsenic sulfide simultaneously for 8 days, or 60.37% and 78.8% in K562 cells was treated with arsenic sulfide for 5 days after affected by IFN-alpha for 3 days. 71.3% telomerase activity was inhibited in K562 cells by arsenic sulfide alone for 8 days. CONCLUSION: Combination of arsenic sulfide and IFN-alpha can increase the apoptosis and inhibit the telomerase activity of K562 cells obviously comparing with the two drugs used alone. IFN-alpha maybe promote arsenic sulfide inducing apoptosis of K562 cells.

[Effect of As(2)O(3) on expressions of COX-2 and matrix metalloproteinases in SGC7901 and K562 cells].

This study was aimed to investigate on effect of As(2)O(3) on expressions of COX-2, MMP-2 and MMP-9 in SGC7901 and K562 cells. SGC7901 and K562 cells were cultured in RPMI 1640 medium and were inoculated in culture medium with different concentrations of As(2)O(3) and at different times. Expressions of COX-2, MMP-2 and MMP-9 in SGC7901 and K562 cells were measured by using Western blot, while the levels of COX-2 mRNA and MMP-2 mRNA were measured with fluorescence quantitative RT-PCR. The results showed that the expression of COX-2, MMP-2 and MMP-9 decreased in dose- and time-dependent manners after treating with As(2)O(3). The levels of COX-2 mRNA and MMP-2 mRNA reduced in groups treated with As(2)O(3). In conclusion, As(2)O(3) inhibits expressions of COX-2, MMP-2 and MMP-9 in K562 and SGC7901 cells, suggesting that As(2)O(3) inhibits tumor development through its effect on angiogenesis involved in solid and hematologic malignancies.

[Effect of arsenic trioxide on vascular endothelial growth factor-C and its receptor (VEGFR-3) in nude mice with gastric cancer].

This study was aimed to investigate the effect of arsenic trioxide (As2O3) on expression of vascular endothelial growth factor-C (VEGF-C) and its receptor VEGFR-3 in gastric cancer in order to clarify the role of As2O3 in lymphangiogenesis and metastasis of tumor. The gastric cancer model was established in nude mice by using gastric cancer cell line SGC-7901. As2O3 was injected to the two treatment groups (2.5 mg/kg and 5 mg/kg) and the same volume of saline solution was injected to the control group. Expression of VEGF-C and VEGFR-3 were detected by immunohistochemistry and were analyzed with QWin550cW image Acquiring & Analysis System. The results showed that the expression of VEGF-C and VEGFR-3 in cancer cells significantly reduced in the arsenic -treated groups. The expression of VEGF-C and VEGFR-3 in 5 mg/kg group was significantly less than that in 2.5 mg/kg group. The gray ratio analysis confirmed that there were significant difference between control group and two treated group, as well as between 2.5 mg/kg-treated group and 5 mg/kg-treated group. It is concluded that As2O3 can inhibit expression of VEGF-C and VEGFR-3 of human gastric cancer xenografts in nude mice, which suggests that As2O3 may inhibit the lymphangiogenesis by suppressing the expression of VEGF-C and VEGFR-3.

Effect of arsenic trioxide on vascular endothelial cell proliferation and expression of vascular endothelial growth factor receptors Flt-1 and KDR in gastric cancer in nude mice.

AIM: To investigate the effect of arsenic trioxide (As2O3) on expression of vascular endothelial growth factor receptor-1 (VEGFR-1, Flt-1) and VEGFR-2 (KDR) in human gastric tumor cells and proliferation of vascular endothelial cells. METHODS: The solid tumor model was formed in nude mice with the gastric cancer cell line SGC-7901. The animals were treated with As2O3. Microvessel density (MVD) and expression of Flt-1 and KDR were detected by immunofluorescence laser confocal microscopy. SGC-7901 cells were treated respectively by exogenous recombinant human VEGF165 or VEGF165 + As2O3. Cell viability was measured by MTT assay. Cell viability of ECV304 cells was measured by MTT assay, and cell cycle and apoptosis were analyzed using flow cytometry. RESULTS: The tumor growth inhibition was 30.33% and 50.85%, respectively, in mice treated with As2O3 2.5 and 5 mg/kg. MVD was significantly lower in arsenic-treated mice than in the control group. The fluorescence intensity levels of Flt-1 and KDR were significantly less in the arsenic-treated mice than in the control group. VEGF165 may accelerate growth of SGC7901 cells, but As2O3 may disturb the stimulating effect of VEGF165. ECV304 cell growth was suppressed by 76.51%, 71.09% and 61.49% after 48 h treatment with As2O3 at 0.5, 2.5 and 5 micromol/L, respectively. Early apoptosis in the As2O3-treated mice was 2.88-5.1 times higher than that in the controls, and late apoptosis was 1.17-1.67 times higher than that in the controls. CONCLUSION: Our results showed that As2O3 delays tumor growth, inhibits MVD, down-regulates Flt-1 and KDR expression, and disturbs the stimulating effect of VEGF165 on the growth of SGC7901 cells. These results suggest that As2O3 might delay growth of gastric tumors through inhibiting the paracrine and autocrine pathways of VEGF/VEGFRs.

Study on the efficacy and safety of Xueyou Mixture in treating hemophilia.

OBJECTIVE: To observe the effect of Xueyou Mixture (, XYM) on blood coagulation factors and its safety in treating hemophilia. METHODS: To the randomly selected 65 inpatients of hemophilia, XYM was administered accompanied with intravenous dripping of liver cell growth factor 60-100 mg once a day to protect the liver, with no blood products like concentrated VIII and FIX factors or blood plasma given. The treatment lasted for 3 weeks. The short-term efficacy and adverse reactions were observed. The long-term efficacy in patients was observed in a follow-up study of 6-12 months after they were discharged from the hospital but continuously took XYM orally. RESULTS: The short-term markedly effective rate in the patients was 95.38% (62/65). After they were treated for 3 weeks, the level of FVIII factor activity increased in 56 patients of type A from (3.32+/-2.21) % to (4.18+/-2.23) %, and in 9 of type B from (4.92+/-1.81) % to (5.64+/-1.96) %. Compared with that before treatment, the difference was significant in both of them (P<0.01). No obvious adverse reaction was found in the treatment period. The follow-up study showed that in 22 patients of type A, the FVIII factor activity ratio increased from (3.25+/-2.11) % to (6.31+/-2.16) %, (8.36+/-1.05) %, and (16.38+/-2.71) % in the 2nd, 3rd and 6th month after discharge respectively, all showing significant difference to that before treatment (P<0.01); and in 4 patients of type B, it increased from (4.15+/-2.26) % to 7.8% and 11.6% (mean value) in the 2nd and 6th month respectively. CONCLUSION: XYM could raise the activity of factors VIII and IX in patients with hemophilia, and the degree of the rise is related with the duration of the therapy, with no obvious adverse reaction, which strikes out a new path and new train of thinking for the treatment of the disease by nonblood preparation.

Study on graded therapy of hemophilic arthritis by integrative traditional Chinese and Western medicine.

OBJECTIVE: To study the effect and safety of graded therapy featuring integrative traditional Chinese and Western medicine for the treatment of hemophilic arthritis. METHODS: Forty patients with hemophilic arthritis were hospitalized randomly, with their blood coagulation factor activity determined by one-stage method and their arthritis classified into 4 stages. The treatment was applied according to the stage of arthritis and finding of intra-articular cavity puncture. For stage I, based on the principle of RICE (rest, ice, compression and elevation), 1.8 g of Xuefuda was medicated orally once per day, intravenous dripping of 250 mL of hemostasis mixture twice a day and 1.2 g of clindamycin per day were also given for hemostasis and anti-inflammation. For stage II-III, Kangyanling was additionally administered via intra-articular cavity injection twice a week, 2 mL every time, for 5-6 times in total. For stage IV, the drug for intra-articular cavity injection was replaced with 25 mg of sodium hyaluronate and the frequency of injection reduced to every two weeks, for 5-6 times in total. Coagulation factors III and IV as well as blood plasma were not given in the whole treatment course. Short-term therapeutic effects and adverse reaction in patients were evaluated, and the long-term effects were followed-up after patients left the hospital with 6-month consolidation therapy by Xuefuda. RESULTS: After a 3-week treatment, 33 patients (82.5%) were completely remitted; 5 (12.5%) were partially remitted and 2 (5.0%) un-remitted, setting the short-term effective rate at 95.0% (38 cases). The 6-month follow-up showed that except for a relapse in 2 and 4 patients of stage III and IV respectively, long-term remission displayed in all the other 34 patients, with the remission sustaining rate being 85.0%. No complication such as an infection, bleeding or aggravating pain occurred in the 215 times intra-articular puncturing conducted in the 40 patients. Normal figures were shown in liver and kidney function, electrolytes, ECG, blood glucose and routine test of blood and urine throughout the course. CONCLUSION: The graded treatment of integrative medicine for hemophilia with non-blood preparation has a favorable effect and is safe or without any adverse reaction, which opens a high efficacy and new safe path and thinking for the treatment of and deformity prevention in the hemophilic patients.

Inhibitory effect of arsenic trioxide on angiogenesis and expression of vascular endothelial growth factor in gastric cancer.

AIM: To investigate the inhibitory effect of As(2)O(3) on angiogenesis of tumor and expression of vascular endothelial growth factor (VEGF) in tumor cells in vivo and in vitro. METHODS: The solid tumor model was formed in nude mice with the gastric cancer cell line SGC-7901. The animals were randomly divided into three groups. As(2)O(3) was injected into the arsenic-treated groups (2.5 mg/kg and 5 mg/kg) and the same volume of saline solution was injected into the control group. Microvessel density (MVD) and expression of VEGF were detected with immunofluorescence laser confocal technology. Further expression of VEGF protein and VEGF mRNA was measured with Western bloting and fluorescence quantitative RT- PCR in SGC-7901 cells treated with As(2)O(3). RESULTS: In nude mice, after treatment with 5 mg/kg and 2.5 mg/kg As(2)O(3) respectively, about 50% and 30% tumor growth inhibition were observed correspondingly (P<0.05, P<0.05). Decrease in MVD appeared in As(2)O(3)-treated tumors compared with control group (P<0.001, P<0.001). MVD in tumors was significantly lower in 5 mg/kg group than in 2.5 mg/kg group (P<0.01). The fluorescence intensity levels of VEGF in tumor cells were significantly lowered in the arsenic-treated groups (P<0.01, P<0.01). The fluorescence intensity level of VEGF in 5 mg/kg group was lower than that in 2.5 mg/kg group (P<0.01). In vitro, the expression of VEGF protein decreased in dose- and time-dependent manner after the treatment with As(2)O(3), but in VEGF mRNA no significant difference was found between the control group and the treated groups. CONCLUSION: As(2)O(3) can inhibit solid tumor growth by inhibiting the formation of new blood vessels. One of the mechanisms is that As(2)O(3) can inhibit VEGF protein expression.

[Effect of realgar on the gene expression profile of multiple myeloma cell line RPMI 8226].

OBJECTIVE: To explore the effect of realgar on the gene expression profiles of multiple myeloma cell line RPMI 8226 by apply cDNA microarray. METHODS: The gene expression of RPMI 8226 cells before and after 48 hours of realgar treatment was determined with a cDNA microarray representing 4096 human genes. RESULTS: At the mRNA level, 164 genes were differentially altered; 53 genes were up-regulated; and 111 genes were down-regulated. CONCLUSION: The realgar treatment to RPMI 8226 cell line may induce a number of gene changes. Many genes may be involved in the pathogenesis of multiple myeloma. BTG1, ALK1, and TXNIP genes may play an important role in the apoptosis and differentiation of RPMI 8226 cells.

[Changes of gene expression profile of multiple myeloma cell line RPMI 8226 treated by arsenic trioxide].

OBJECTIVE: To compare the changes of gene expression profiles of multiple myeloma cell line RPMI 8226 before and after 24-hour intervention of arsenic trioxide. METHODS: The responses of the RPMI 8226 cells to arsenic trioxide were determined with cDNA microarray which included 4,096 different human genes. RESULTS: Of these 4,096 genes, the expressions of 273 genes were altered significantly at mRNA level. The expressions of 121 genes were up-regulated while the expressions of 152 genes were down-regulated. CONCLUSION: The effect of arsenic trioxide on RPMI 8226 cells is related to changing the expression levels of a number of genes. ZFYVE16, ALK1 and TXNIP genes may play important roles in apoptosis and differentiation of RPMI 8226 cells.

[Construction and identification of the recombinant prokaryotic expression plasmid containingbetapep-25 peptide].

AIM: To synthesize antiangiogenic peptide fragment of betapep-25, to construct and identify the recombinant prokaryotic expression plasmid containing betapep-25 peptide. METHODS: The fragment encoding betapep-25 peptide was designed and synthesized artificially and was cloned into vector pGEM-T easy after being identified by sequencing. After being digested by Nae I and BamH I, T-betapep-25 peptide fragment was cloned into recombinant vector pBV220-NT4, which was digested by Nae I and BamH I. The constructed recombinant prokaryotic expression plasmid pBV220-NT4-betapep-25 was digested using BamH I, EcoR I and BamH I, respectively. RESULTS: The sequcence of betapep-25 synthesized artificially and analyzed by digestion was consistent with the published results. Fragments of 4,030 bp, 364 bp and 3,666 bp were obtained after digestion of recombinant prokaryotic expression plasmid pBV220-NT4-betapep-25 using BamH I, EcoR I and BamH I, respectively, which demonstrated the successful cloning and construction of recombinant prokaryotic expression plasmid. CONCLUSION: The successful construction recombinant prokaryotic expression plasmid expressing betapep-25 provides a foundation for further research on its mechanism of anti-tumor activity in vivo and in vitro.

High expression of bcl-x(L) in K562 cells and its role in the low sensitivity of K562 to realgar-induced apoptosis.

Arsenic compounds (As(2)O(3 )or()As(4)S(4)) have been used successfully for the treatment of acute promyelocytic leukemia (APL) for quite a long time. It has been noticed that the sensitivity to apoptosis induced by As(2)O(3 )varies among various leukemia cells. It was reported by several groups that As(2)O(3) could induce apoptosis in APL-derived NB4 cells at concentrations of 0.5-1 mumol/l, whereas in other leukemia cells like K562, As(2)O(3) has no effects at the same concentration. K562 cells undergo apoptosis only when the concentration of As(2)O(3 )is greater than 2 mumol/l. Another arsenic compound, realgar (As(4)S(4)), a traditional Chinese mineral medicine, has been used to treat APL effectively and demonstrated to have lower toxicity than As(2)O(3). It would be interesting to know whether NB4 and K562 cells will show different sensitivity to realgar as well and if there is a difference, what is the cellular mechanism of it. In our present study, K562 cells were much less sensitive than NB4 cells to apoptosis induced by realgar. We confirm that the expression of bcl-x(L) is significantly higher in K562 cells than that in NB4 cells and is not downregulated upon realgar treatment. K562 cells become sensitive to realgar at clinically acceptable concentrations when bcl-x(L) expression level is downregulated by transfecting bcl-x(L) antisense RNA vector into the cells. Our results suggest that the increased bcl-x(L) expression in K562 cells contributes to its insensitivity to realgar-induced apoptosis.