Interferon-alpha-2b induces molecular responses of patients with polycythemia vera and its post-polycythemic myelofibrosis / 中国实验血液学杂志

To evaluate the efficacy and safety of interferon-alpha-2b (IFN-α-2b) in polycythemia vera patients(PV patient) with or without post-polycythemic myelofibrosis (post-PV MF), 30 patients with mutated JAK2V617F were enrolled in this study, from which 29 patients were evaluable. The percentage of mutated JAK2V617F allele (V617F%) was evaluated by real-time polymerase chain reaction (RT-PCR) before and after treatment with IFN-α-2b. The correlation of V617F allele burden with the major clinical outcomes was studied. Adverse effects appeared in patients was observed. The results showed that the median follow-up was 24 (12 - 42) months for 29 evaluable patients. Complete hematologic response was achieved in 10%, 48%, 72% and 78% of patients after treatment for 6, 12, 24 and 36 months respectively. The detection of V617F allele burden revealed that the molecular remission of patients (V617F%) was achieved in 41%, 76%, 89% and 89% after treatment for 6, 12, 24 and 36 months respectively. Molecular complete remission (JAK2V617F undetectable) was achieved in 4 patients, lasted from 6 to 12 months after IFN-α-2b discontinuation. The decrease of V617F% in patients with post-PV MF was significantly higher than that in patients without post-PV MF (53 ± 18% vs 32 ± 22%, respectively; p = 0.031) after treatment for 12 months. PV patients had a good tolerance to IFN-α-2b. It is concluded that IFN-α-2b can decrease the mutated V617F allele burden. Patients with PV, especially with post-PV MF, can achieve molecular remission after treatment with IFN-α-2b.

Expression of TGF-beta1 and E-cadherin in primary and metastatic ovarian carcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To detect the expression of the protein of TGF-beta1 and E-cadherin in the primary and metastatic lesions of ovarian carcinoma and explore the mechanism of the metastasis of ovarian carcinoma.</p><p><b>METHODS</b>Immunohistochemistry (IHC) was performed to detect the expression of TGF-beta1 and E-cadherin proteins in primary and metastatic ovarian carcinoma, benign epithelial ovarian tumor and normal ovarian tissue.</p><p><b>RESULTS</b>The expression of TGF-beta1 was significantly higher in ovarian carcinoma (67.2%) than in benign tumors (28.6%) and normal ovarian tissue (18.9%) (Chi2=26.94, P<0.001), but E-cadherin expression showed a reverse pattern. TGF-beta1 expression in the primary ovarian carcinoma carcinoma was associated with the FIGO stage, lymph metastasis and ascites of the tumor (P=0.01, P=0.01, and P=0.04, respectively). E-cadherin expression in the tumor was associated with the differentiation (P=0.02) and lymph metastasis of ovarian carcinoma (P=0.04). The expressions of TGF-beta1 and E-cadherin were all significantly lower in the primary tumors than in the metastatic tumor (Chi2=4.70, P=0.03; Chi2=5.91, P=0.015). A significant correlation was found between the expressions of the TGF-beta1 and E-cadherin in the primary carcinoma (Kappa value of -0.32, P=0.01).</p><p><b>CONCLUSION</b>TGF-beta1 and E-cadherin are closely associated with the metastasis of ovarian carcinoma and might be potential targets for controlling the metastasis of ovarian carcinoma.</p>

Effect of calmodulin antagonist O-4-ethoxyl- butyl-berbamine on the proliferation of human breast cancer cell line MCF-7 and its relevant mechanism / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of calmodulin antagonist O-(4-ethoxyl-butyl)-berbamine (EBB) on proliferation of human breast cancer cell MCF-7 and its possible mechanism.</p><p><b>METHODS</b>MTT assay was used to analyze the effect of EBB on tumor cells growth. Flow cytometry was used to detect its impact on the cell cycle of MCF-7 cells. Immunofluoresce labeling technique and laser scanning confocal microscope were used to reveal the changes of the microtubule, microfilament, mitochondrion, and endoplasmic reticulum in the cells.</p><p><b>RESULTS</b>The IC50 value of EBB in MCF-7 cells was (13.0 +/- 3.7) micromol/L. MCF-7 cells were arrested at S phase after EBB treatment. Meanwhile, depolymerization of the microtubule and microfilament, impairment of the mitochondrion and swelling of endoplasmic reticulum were observed.</p><p><b>CONCLUSION</b>EBB arrests MCF-7 cells at S phase by inhibiting the growth of MCF-7 cells, which may be related to the changes of structures and functions of the microtubule, microfilament, mitochondrion, and endoplasmic reticulum.</p>

The influence of Ara-C on anti-CD3/anti-Pgp mediating T-lymphocytes activities against multi-drug resistant leukemia cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the role of Ara-C in regulating anti-CD3/anti-Pgp mediating T-lymphocytes activities against multi-drug resistant leukemia cells.</p><p><b>METHODS</b>The diabody of anti-CD3/anti-Pgp was purified by E-tag affinity chromatography. K562 and K562/A02 cells were treated with Ara-C. The expressions of B7-1 and B7-2 on K562 and K562/AO2 cells were detected by FACS. The cytotoxicity of T-lymphocytes combined with anti-CD3/anU-Pgp plus Ara-C was analyzed by CytoTox 96 nonradioactive method.</p><p><b>RESULTS</b>The expressions of B7-1 and B7-2 on K562 and K562/A02 cells treated by Ara-C was significantly higher than those untreated. The effect/target ratio was from 0.39:1 to 25:1, and the killing rate of activated T cells to anti-drug-resistant leukemia cells was from (16.44 +/- 1.20)% to (60.49 +/- 2.90)%. The killing rates were increased gradually, with both the effect/target ratio and the antibody concentration increasing (P < 0.05).</p><p><b>CONCLUSION</b>Ara-C may be an important adjuvant for improving anti-CD3/anti-Pgp mediating T-lymphocytes activities against multi-drug resistant leukemia cells.</p>

Three-step purification of preparative-scale antiCD20 (Fab')2 / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish a three-step purification method of preparative-scale antiCD20 (Fab')2 using AKTA prime.</p><p><b>METHODS</b>AntiCD20 (Fab')2 was extracted by hyperosmotic solution and then purified by CM sepharose FF, phenyl sepharose FF, and protein G sepharose FF.</p><p><b>RESULTS</b>Around 8 mg anti-CD20 (Fab')2, whose purification was 96.678%, was purified. The antigen-binding activity of antiCD20 (Fab')2 was similar to that of antiCD20 (Fab')2 purified by protein G sepharose FF and S-100.</p><p><b>CONCLUSION</b>The three-step purification method can obtain high-purity preparative-scale antiCD20 (Fab')2 in a simple way.</p>

Mechanism of synergistic anti-tumor effect of PH II -7 with doxorubicin on multi-drug resistant HL-60/ADR cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the synergistic mechanism between PH II -7 and doxorubicin against multi-drug resistant HL-60/ADR cells and its parent HL-60 cells.</p><p><b>METHODS</b>The anti-tumor activity of doxorubicin alone and combined with PH II -7 were measured by MTT assay. RNA was extracted from the cells treated with PH II -7 for different times or doses then the expression of MRP gene was measured by RT-PCR. Confocal laser scanning microscopy and FACS were used to detect the intracellular cumulation of doxorubicin in PH II -7 treated HL-60 and HL-60/ADR cells.</p><p><b>RESULTS</b>PH II -7 has anti-tumor effect with IC50 of (0.83 +/- 0.08) micromol/L and (1.74 +/- 0.56) micromol/L for HL-60 and HL-60/ADR, respectively. It could potentiate the anti-tumor effect of doxorubicin with CDI of 0.7 and 0.43 for HL-60 and HL-60/ADR, respectively. PH II -7 and doxorubicin act synergistically in inhibiting the proliferation of HL-60 and HL-60/ADR cells and down-regulating the expression of MRP gene in a dose and time dependent manner. PH II -7 restored the intracellular cumulation of doxorubicin in HL-60/ADR cells to 55% of that in HL-60 cells.</p><p><b>CONCLUSION</b>PH II -7 can significantly hasten the cytotoxicity of doxorubicin to HL-60 and HL-60/ADR cells through down-regulating the expression of MRP. The synergistic effect was more obvious in HL-60/ADR cells.</p>

Preparation and activity detection of monoclonal antibody against anti-CD3 ScFv / 中国医学科学院学报

<p><b>OBJECTIVE</b>To prepare monoclonal antibody (McAb) against anti-CD3 ScFv for purifying and detecting serum anti-CD3 antibody concentration.</p><p><b>METHODS</b>McAb against anti-CD3 ScFv was prepared by hybridoma technique and used to prepare affinity chromatography column, which was used to purify anti-CD3 ScFv and Diabody [CD3 x Pgp] without E-tag. The binding activities of anti-CD3 ScFv, Diabody [CD3 x Pgp] without E-tag, and Diabody [CD3 x Pgp] purified by anti-CD3 affinity chromatography column or anti-E-tag affinity chromatography column against K562/A02 cell and Jurket cells were detected by fluorescence activated cell sorting (FACS) method. ELISA was used to identify the specificity of the McAb.</p><p><b>RESULTS</b>McAb against anti-CD3 ScFv specifically detected serum anti-CD3 ScFv without reacting with sera. The anti-CD3 ScFv purified by anti-CD3 affinity chromatography column and purified by anti-E-tag affinity chromatography column had the same specific binding activity with Jurkat cells. The positive binding rates of Diabody [CD3 x Pgp] without E-tag to K562/A02 and Jurkat cells were 89.87% and 83.95%, respectively. In the competitive binding experiments with K562/A02 and Jurkat cells, the binding rates of Diabody [CD3 x Pgp] without E-tag decreased to 56.30% and 43.78%, respectively.</p><p><b>CONCLUSION</b>The McAb against anti-CD3 ScFv prepared in our lab can be used to purify and detect serum anti-CD3 antibody concentration.</p>

An anti-P-gp/anti-CD3 bispecific antibody cytotoxic to human multidrug resistant KB cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the specific cytotoxicity mediated by anti-P-gp/anti-CD(3) diabodies in multidrug resistant solid tumor using P-gp as target.</p><p><b>METHODS</b>The anti-P-gp/anti-CD(3) diabodies were secreted from E. coli strain 16C9 containing the expression plasmid PAYZDCP, grown at 30 degrees C in a shaker flask; the diabodies were purified by affinity chromatography and identified by SDS-PAGE; the effect of the anti-P-gp/anti-CD(3) diabody mediated lysis of P-gp-expressing tumor cells was assayed by (51)Cr release assay in vitro, and by human KB nude mouse xenograft models in vivo.</p><p><b>RESULTS</b>The diabodies were generated by bacteria as a soluble functional form and purified by one-step affinity chromatography with a yield > 4 mg/L culture medium. In (51)Cr release assay, the diabodies targeted human activated T cells to lyse P-gp(+)-KB/MDR cells in a dose-dependent manner. It suggested that the diabody was able to induce an efficient lysis of the target cells by human T cells in vitro. When combined with activated human T cells, the diabody significantly inhibited the growth of KB/MDR, but had no effect on KB xenografts.</p><p><b>CONCLUSION</b>The anti-P-gp/anti-CD(3) bispecific antibody is a potent agent for targeting human T lymphocytes to lyse solid tumor cells overexpressing P-gp in vitro and in vivo.</p>

Specific targeting cytotoxicity to resistant leukemia cells mediated by anti-Pgp/anti-CD3 diabody / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the specific targeting cytotoxicity to drug-resistant leukemia cells mediated by anti-Pgp/anti-CD3 diabody.</p><p><b>METHODS</b>The diabody was purified by affinity chromatography and identified by SDS-PAGE and FACS. The effect of the anti-Pgp/anti-CD3 diabody mediated lysis of Pgp-expressing tumor cells was assayed by human leukemia nude mice xenograft model in vivo.</p><p><b>RESULTS</b>The diabody was produced in E.coli in a soluble functional form and could bind both Jurkat cells (CD3(+)) and K562/A02 cells (Pgp(+)). The binding rates were 86.25% and 86.26%, respectively. It could inhibit tumor growth by 98.57% and prolonged the survival of mice bearing xenografted K562/A02 cells.</p><p><b>CONCLUSION</b>The diabody was proved to be a potent agent for mediating T lymphocyte cytotoxicity to lyse Pgp expressing tumor cells in vitro and in vivo.</p>

One amino acid mutation in an anti-CD20 antibody fragment that affects the yield bacterial secretion and the affinity / 生物工程学报

Monoclonal antibodies (mAb) directed against CD20, either unmodified or in radiolabeled forms, have been successfully exploited in clinic as effective therapeutic agents in the management of non-Hodgkin's B-cell lymphoma. The antibody fragment is a potential agent in image and therapy of tumor. To further improve the soluble expression of anti-CD20 antibody Fab' fragment, PCR was used to mutate the anti-CD20 VL and VH genes and its biological activity was identified. The expression vector of chimeric antibody Fab' was constructed and expressed in E. coli. The data of mutant clone DNA sequence showed that the amino acid of light chain gene of the parent anti-CD20 antibody (H47) was successful mutated as Ser (GAG)-Asn (CAG). The soluble expression of mutated anti-CD20 Fab' (CD20-7) was 3.8 mg/g dry cell weight, while the parent (CD20-2) was 1.3 mg/g dry cell weight. The affinity constant Ka of CD20-7 was 2.2 x 10(9) L/mol. The primary results of competitive assays by FACS showed that CD20-7 could partially block the sites through which parent antibody (HI47) bind to Raji cells. There was difference in the Raji cells (CD20+)-binding activity between the mutant CD20-7 and parent CD20-2. The site mutation of anti-CD20 Fab' gene make it possible that the anti-CD20 antibody fragment was succeeded to obtain higher expression. In this thesis, we succeeded in completing mutation and expression of anti-CD20 Fab' genes, distinguishing its biological activity, and obtaining its highly expression. These period results will lay a foundation for development of other kind of anti-CD20 engineering antibody (for instance: Fab' Diabody and miniantibody), and make it possible for anti-CD20 antibody to be applied to tumor therapy in civil in the future.