[Effect of Recombinant Human Thrombopoietin (rhTPO) on Long-term Hematopoietic Recovery in Mice with Acute Radiation Sickness and Relative Mechanism].

OBJECTIVE: To investigate the effect and relative mechanism of Recombinant Human Thrombopoietin (rhTPO) on long-term hematopoietic recovery in mice with acute radiation sickness. METHODS: Mice were intramuscularly injected with rhTPO (100 µg/kg) 2 hours after total body irradiation with 60Co γ-rays (6.5 Gy). Moreover, six months after irradiation, peripheral blood, hematopoietic stem cells (HSC) ratio, competitive transplantation survival rate and chimerization rate, senescence rate of c-kit+ HSC, and p16 and p38 mRNA expression of c-kit+ HSC were detected. RESULTS: Six months after 6.5 Gy γ-ray irradiation, there were no differences in peripheral blood white blood cells, red blood cells, platelets, neutrophils and bone marrow nucleated cells in normal group, irradiated group and rhTPO group (P>0.05). The proportion of hematopoietic stem cells and multipotent progenitor cells in mice of irradiated group was significantly decreased after irradiation (P<0.05), but there was no significant changes in rhTPO group (P>0.05). The counts of CFU-MK and BFU-E in irradiated group were significantly lower than that in normal group, and rhTPO group was higher than that of the irradiated group(P<0.05). The 70 day survival rate of recipient mice in normal group and rhTPO group was 100%, and all mice died in irradiation group. The senescence positive rates of c-kit+ HSC in normal group, irradiation group and rhTPO group were 6.11%, 9.54% and 6.01%, respectively (P<0.01). Compared with the normal group, the p16 and p38 mRNA expression of c-kit+ HSC in the irradiated mice were significantly increased (P<0.01), and it was markedly decreased after rhTPO administration (P<0.01). CONCLUSION: The hematopoietic function of mice is still decreased 6 months after 6.5 Gy γ-ray irradiation, suggesting that there may be long-term damage. High-dose administration of rhTPO in the treatment of acute radiation sickness can reduce the senescence of HSC through p38-p16 pathway and improve the long-term damage of hematopoietic function in mice with acute radiation sickness.

Steroidal glycosides from the rhizomes of Anemarrhena asphodeloides and their antiplatelet aggregation activity.

Five new steroidal glycosides, timosaponin J ( 1), timosaponin K ( 2), (25 S)-karatavioside C ( 5), timosaponin L ( 6), and (25 S)-officinalisnin-I ( 8), together with eight known steroidal saponins, timosaponin E (1) ( 3), purpureagitosid ( 4), timosaponin BII ( 7), timosaponin B III ( 9), anemarrhenasaponin I ( 10), anemarrhenasaponin III ( 11), anemarrhenasaponin A (2) ( 12), and timosaponin A III ( 13), were isolated from the rhizomes of Anemarrhena asphodeloides. Their structures were elucidated on the basis of spectroscopic and chemical evidence. The aglycones of compounds 1 and 2 are new aglycones. Compounds 1- 13 were evaluated for their platelet aggregation activities, and compound 13 exhibited the strongest inhibitory effect on adenosine diphosphate (ADP)-induced platelet aggregation.

[Cell Cycle Arrest and Apoptosis Induced by Atovaquone in Non-Hodgkin's Lymphoma Raji Cells].

OBJECTIVE: To investigate the effect of atovaquone on the cell cycle and apoptosis of non-Hodgkin's lymphoma Raji cells, and clarify the related mechanisms. METHODS: MTT assay and trypan blue dye exclusion method were used to evaluate the effect of atovaquone on the proliferation of Raji cells. After the cells were stained by PI staining, the cell cycle distribution was detected by flow cytometry. Cell apoptosis was analyzed by Annexin V/PI double binding assay. The intracellular alterations of reactive oxygen species were detected by 2', 7'-dichlorofluorescein diacetate (DCFH-DA). The protein expression of cell cycle and apoptosis related molecules were detected by Western blot. RESULTS: Various concentrations of atovaquone (5-40 µmol/L) inhibited the growth of Raji cells in a concentration-dependent manner (r=0.951). The proliferation of Raji cells was significantly inhibited after treated by atovaquone (20 and 30 µmol/L) for 24, 48 and 72 h, which showed statistically different with that in the control group (P<0.01, P<0.001, P<0.001). G1 phase arrest (P<0.01, P<0.001) and apoptosis (P<0.01) of Raji cells was induced by atovaquone (20 and 30 µmol/L) significantly for 24 h and 48 h, respectively. The expression of p-JAK2 and p-STAT3(Y705) protein were down-regulated significantly induced by atovaquone (P<0.001, P<0.05). Furthermore, atovaquone treatment could induce the decreasing of antiapoptotic protein Mcl-1, Bcl-2, and Bcl-xl expression level (P<0.05) and increasing of cleaved caspase-3 protein expression level. In addition, atovaquone could also induce the down-regulation of c-Myc (P<0.001, P<0.01) and cell cycle related molecules Cyclin D1, CDK4, and CDK6 (P<0.01, P<0.05) protein expression. CONCLUSION: Atovaquone effectively inhibits cell proliferation and induces cell cycle arrest and apoptosis by suppression of STAT3 signaling pathway in Raji cells. It can be a potential therapeutic agent against non-Hodgkin's lymphoma.

Inhibition of pyrimidine biosynthesis by strobilurin derivatives induces differentiation of acute myeloid leukemia cells.

All-trans retinoic acid-based differentiation therapies have succeeded in the treatment of acute promyelocytic leukemia, which is a rare subtype of acute myeloid leukemia (AML). Their clinical efficacy is negligible, however, for other subtypes of AML. Here, we showed that strobilurin derivatives, a well-established class of inhibitors of mitochondrial electron transport chain (ETC) complex III, possessed differentiation-inducing activity in AML cells. Impairment of mitochondrial ETC activity was involved in the differentiation effects of strobilurin derivatives, where reactive oxygen species generation appeared unnecessary. Conversely, strobilurin derivative-mediated differentiation was triggered by pyrimidine deficiency, which resulted from the inhibition of the mitochondrial-coupled dihydroorotate dehydrogenase enzyme. Moreover, strobilurin derivative-mediated pyrimidine depletion led to the activation of the Akt/mTOR cascade, which was required for the differentiation. Our study provided evidence that strobilurin derivatives may represent a novel class of differentiation-inducing agents for the treatment of AML.

[Therapeutic Effect of Single Intramuscular Administration of Recombinant Human Thrombopoietin on Rhesus Monkeys with Acute radiation Sickness].

OBJECTIVE: To confirm the therapeutic effect of recombinant human thrombopoietin (rhTPO) on rhesus monkeys irradiated with 5.0 Gy 60Co γ-ray, and provide experimental basis for clinical treatment of similar patients. METHODS: Fourteen adult rhesus monkeys were irradiated with 60Co γ-ray on both sides at the dose of 5.0 Gy (dose rate 69.2 cGy/min) to establish the acute radiation sickness model. The monkeys were divided into irradiation group (n=5), rhTPO 5 µg/kg group (n=4) and rhTPO 10 µg/kg group (n=5). Two hours after irradiation, the three groups of monkeys were injected with saline 0.1 ml/kg, rhTPO 5 µg/kg（0.1 ml/kg） and rhTPO 10 µg/kg(0.2 ml/kg), respectively. The general signs, survival, peripheral hemogram and serum biochemistry of rhesus monkeys were observed before and after irradiation, and the differences between rhTPO group and irradiation control group were compared. RESULTS: After total body irradiation with 5.0 Gy60Co γ-ray, rhesus monkeys successively showed fever, hemorrhage, sharp decrease of whole blood cell counts in peripheral blood and disorder of serum biochemical indexes. Compared with the irradiated control group, a single intramuscular injection of rhTPO 5 µg/kg or 10 µg/kg 2 hours after irradiation could improve the symptoms of fever and bleeding, increase the nadir of peripheral red blood cells and platelets counts, shorten the duration of hemocytopenia, and advance the time for blood cells to return to the pre-irradiation level. The serum biochemical results showed that rhTPO could improve the abnormality of serum biochemical indexes in rhesus monkeys induced by 5.0 Gy total body irradiation to some extent. Compared with the two administration groups, the therapeutic effect of rhTPO 10 µg/ kg was better. CONCLUSION: A single injection of rhTPO 5 µg/ kg or 10 µg/ kg 2 hours after irradiation can alleviate the injury of multilineage hematopoiesis and promote the recovery in monkeys irradiated by 5.0 Gy γ-ray. It also improves animal signs and has obvious therapeutic effect on acute radiation sickness.

[Effect of Interleukin-6 Gene Deletion on Radiation-Induced Mouse Hematopoietic Injury and Relative Mechanism].

OBJECTIVE: To study the effect of interleukin-6 (IL-6) gene deletion on radiation-induced hematopoietic injury in mice and relative mechanism. METHODS: Before and after whole body 60Co γ-ray irradiation, it was analyzed and compared that the difference of peripheral hemogram, bone marrow hematopoietic stem and progenitor cells conts in IL-6 gene knockout (IL-6-/-) and wild-type (IL-6+/+) mice and serum IL-6 and G-CSF expression levels in above- mentioned mouse were detected. Moreover, 30 days survival rate of IL-6-/- and IL-6+/+ mice after 8.0 Gy γ-ray irradiation were analyzed. RESULTS: IL-6 levels in serum of IL-6+/+ and IL-6-/- mice were respectively (98.95±3.85) pg/ml and (18.36±5.61) pg/ml, which showed a significant statistical differences (P<0.001). There were no significant differences of peripheral blood cell counts and G-CSF level in serum between IL-6+/+ and IL-6-/- mice before irradiation (P>0.05). However, the number of leukocytes, neutrophils, lymphocytes, monocytes, platelets in peripheral blood and G-CSF level in serum of IL-6-/- mice were significantly decreased at 6 h after 8.0 Gy γ-ray irradiation compared with that of IL-6+/+ mice. On days 30 after 8.0 Gy γ-ray irradiation, the survival rate of IL-6+/+ and IL-6-/- mice was 62.5% and 12.5%, and the mean survival time of dead mice was 16.0±1.0 and 10.6±5.3 days, respectively. On days 14 after 6.5 Gy γ-ray irradiation, bone marrow nucleated cells in IL-6+/+ and IL-6-/- mice were respectively (10.0±1.2)×106 and (8.3±2.2)×106 per femur. Compared with IL-6+/+ mice, the proportion of Lin-Sca-1-c-kit+ (LK) in bone marrow of IL-6-/- mice had no significant change (P>0.05), but the proportion of Lin-Sca-1+c-kit+ (LSK) was significantly decreased (P<0.05). CONCLUSION: IL-6 plays an obvious role in regulating hematopoietic radiation injury, and IL-6 deficiency can inhibit the radiation-induced increase of endogenous G-CSF level in serum, aggravates the damage of mouse hematopoietic stem cells（HSC） and the reduction of mature blood cells in peripheral blood caused by ionizing irradiation, resulting in the shortening of the survival time and significant decrease of the survival rate of mice exposed to lethal dose radiation.

[Establishment of AML Mouse Model by Transplantation of Hematopoietic Cells from MLL-AF9 Transgenic Mice].

OBJECTIVE: To establish a leukemia mouse model induced by transplantation of hematopoietic cells from mixed lineage leukemia (MLL)-AF9 transgenic mice so as to provide the basis for the mechanism research and drug screening of acute myeloid leukemia (AML). METHODS: MLL-AF9 knock-in mice were bred and identified. When the mice developed leukemia, white blood cell (WBC) count in peripheral blood, flow cytometry and morphology method were analyzed to identify the disease. When the WBC count in peripheral blood was more than 100×109/L, bone marrow cells and spleen cells were collected and cryopresevated. After resuscitation, the cells were injected into 4.5 Gy irradiated wild C57BL/6J mice through the tail vein to develop MLL-AF9 leukemia mouse model. Finally, the therapeutic effect was evaluated by positive drug on the model. RESULTS: The natural onset times of leukemia on MLL-AF9 knock-in mice were 22-28 weeks. The spleens of the transgenic mice enlarged and the bone marrow showed the immature forms of myeloid leukemia cells. Both the bone marrow and spleen cells highly expressed myeloid markers, CD11b and Gr-1. At least 0.5×106 bone marrow cells and 2.5×106 spleen cells could induce leukemia in all recipient mice, and the median survival times of mice were 20 days and 36 days, respectively. Experimental treatment was carried out on the leukemia mouse model transplanted with MLL-AF9 spleen cells, and it was found that the traditional chemotherapy drug cytarabine could delay the onset of leukemia and prolong the survival time of the mouse model. CONCLUSION: The leukemia model of hematopoietic cell transplantation based on MLL-AF9 transgenic mice is successfully established, which can be used for the study of the pathogenesis and evaluation of therapeutic effect of AML.

Salt-inducible kinase inhibition sensitizes human acute myeloid leukemia cells to all-trans retinoic acid-induced differentiation.

Differentiation therapies with all-trans retinoic acid (ATRA) have been successful in treating acute promyelocytic leukemia, a rare subtype of acute myeloid leukemia (AML). However, their efficacy is limited in the case of other AML subtypes. Here, we show that the combination of ATRA with salt-inducible kinase (SIK) inhibition significantly enhances ATRA-mediated AML differentiation. SIK inhibition augmented the ability of ATRA to induce growth inhibition and G1 cell cycle arrest of AML cells. Moreover, combining ATRA and SIK inhibition synergistically activated the Akt signaling pathway but not the MAPK pathway. Pharmacological blockade of Akt activity suppressed the combination-induced differentiation, indicating an essential role for Akt in the action of the combination treatment. Taken together, our study reveals a novel role for SIK in the regulation of ATRA-mediated AML differentiation, implicating the combination of ATRA and SIK inhibition as a promising approach for future differentiation therapy.

Fluacrypyrim, a novel STAT3 activation inhibitor, induces cell cycle arrest and apoptosis in cancer cells harboring constitutively-active STAT3.

STAT3 protein has an important role in oncogenesis and is a promising anticancer target. Herein, we demonstrate that a novel small molecule fluacrypyrim (FAPM) inhibits the growth of leukemia cells by a predominant G1 arrest with significant decrease of the protein and mRNA levels of cyclin D1. As cyclin D1 is transcriptionally regulated by STAT3, FAPM is then shown to markedly inhibit the STAT3 phosphorylation with marginal effect on the other signal transducers and activators of transcription, and without effect on phosphoinositide-3-kinase and mitogen-activated protein kinase pathways. Further analysis shows that FAPM significantly increases the protein tyrosine phosphatases (PTPs) activity in a dose-dependent manner, and the inhibition of PTP activation by sodium pervanadate reverses FAPM-induced suppression of STAT3 tyrosine phosphorylation, indicating an important role of PTP in the action of FAPM. Finally, FAPM treatment results in selective suppression of STAT3-mediated transcriptional activity and its downstream effectors, and subsequent induction of growth arrest and apoptosis in STAT3-dependent cancer cell lines. This study therefore identifies FAPM as a potent STAT3 activation inhibitor with possible therapeutic potential against malignancies with constitutive STAT3 activation.

Single-Dose Administration of Recombinant Human Thrombopoietin Mitigates Total Body Irradiation-Induced Hematopoietic System Injury in Mice and Nonhuman Primates.

PURPOSE: Recombinant human thrombopoietin (rhTPO) has been evaluated as a therapeutic intervention for radiation-induced myelosuppression. However, the immunogenicity induced by a repeated-dosing strategy raises concerns about the therapeutic use of rhTPO. In this study, single-dose administration of rhTPO was evaluated for efficacy in the hematopoietic response and survival effect on mice and nonhuman primates exposed to total body irradiation (TBI). METHODS AND MATERIALS: Survival of lethally (9.0 Gy) irradiated C57BL/6J male mice was observed for 30 days after irradiation. Hematologic evaluations were performed on C57BL/6J male mice given a sublethal dose of radiation (6.5 Gy). Furthermore, in sublethally irradiated mice, we performed bone marrow (BM) histologic evaluation and evaluated BM-derived clonogenic activity. Next, the proportion and number of hematopoietic stem cells (HSCs) were analyzed. Competitive repopulation experiments were conducted to assess the multilineage engraftment of irradiated HSCs after BM transplantation. Flow cytometry was used to evaluate DNA damage, cell apoptosis, and cell cycle stage in HSCs after irradiation. Finally, we evaluated the efficacy of a single dose of rhTPO administered after 7 Gy TBI in male and female rhesus monkeys. RESULTS: A single administration of rhTPO 2 hours after irradiation significantly mitigated TBI-induced death in mice. rhTPO promoted multilineage hematopoietic recovery, increasing peripheral blood cell counts, BM cellularity, and BM colony-forming ability. rhTPO administration led to an accelerated recovery of BM HSC frequency and multilineage engraftment after transplantation. rhTPO treatment reduced radiation-induced DNA damage and apoptosis and promoted HSC proliferation after TBI. Notably, a single administration of rhTPO significantly promoted multilineage hematopoietic recovery and improved survival in nonhuman primates after TBI. CONCLUSIONS: These findings indicate that early intervention with a single administration of rhTPO may represent a promising and effective radiomitigative strategy for victims of radiation disasters.

Vibsanol A induces differentiation of acute myeloid leukemia cells via activation of the PKC signaling pathway and induction of ROS.

Identifying novel differentiating agents to promote leukemia-cell differentiation is a pressing need. Here, we demonstrated that vibsanol A, a vibsane-type diterpenoid, inhibited the growth of acute myeloid leukemia (AML) cells via induction of cell differentiation, which was characterized by G1 cell cycle arrest. The differentiation-inducing effects of vibsanol A were dependent upon protein kinase C (PKC) activation, and subsequent activation of the extracellular signal-regulated kinase (ERK) pathway. Furthermore, vibsanol A treatment increased reactive oxygen species (ROS) levels, and the ROS scavenger NAC reversed the vibsanol A-induced cell differentiation, indicating an important role for ROS in the action of vibsanol A. Finally, vibsanol A exhibited a differentiation-enhancing effect when used in combination with all-trans retinoic acid in AML cells. Overall results suggested that vibsanol A induces AML cell differentiation via activation of the PKC/ERK signaling and induction of ROS. Vibsanol A may prove to be an effective differentiating agent against AML.

A5, a new small-molecule inhibitor of CD4 D1 obtained from a computer-aided screening method, contributes to the inhibition of CD4+ T-cell function.

In this study, the authors apply a computer-based strategy to screen thousands of small-molecule, nonpeptidic organic compounds in the Available Chemicals Directory database and to select a series of potential candidates as ligands of the proposed CD4 D1 surface pocket. Then, several cell-based models are used to determine the actual biological functions of these compounds. A small molecule designated A5 (N-((pyridine-4-yl)methylene)thiophene-2-carbohydrazide) was obtained by a virtual screening followed by 3 cell-based functional assays. The results show that A5 could specifically block the CD4-major histocompatibility complex II binding in a rosetting assay, inhibit the mixed lymphocyte reaction-induced T-cell proliferation in a concentration-dependent manner, and reduce the PMA plus ionomycin-stimulated interleukin-2 secretion from peripheral blood mononuclear cells.

J2 prolongs the corneal allograft survival through inhibition of the CD4+ T cell-mediated response in vivo.

In our previous report, we described a novel non-peptidic organic ligand of CD4 D1, designated J2, as a potential inhibitor of CD4 D1 and thus CD4-dependent T cell responses in vitro. In this work, we further used a murine model of corneal allograft rejection to determine its in vivo immunosuppressive activities. To mimic the situation in high-risk human eyes, the recipient mice corneas were all induced by intrastromal sutures to serve as neovascularized graft beds. J2 was administrated by mouth 3 h before transplantation and thereafter on consecutive 12 days. The results showed that J2 could significantly prolong the median survival time of the corneal allografts, compared to the untreated control group. And the subsequent functional assays, including T cell phenotype analysis, delayed-type hypersensitivity (DTH) and enzyme-linked immunospot (ELISPOT) assays revealed that the immunosuppressive activity of J2 was associated with its inhibitory effects on the CD4(+) T cells and these cells-mediated responses. All these results suggest that J2 is a potential lead for the development of new immunosuppressive agents to prevent the corneal allograft rejection.

Succinate ester derivative of δ-tocopherol enhances the protective effects against 60Co γ-ray-induced hematopoietic injury through granulocyte colony-stimulating factor induction in mice.

α-tocopherol succinate (α-TOS), γ-tocotrienol (GT3) and δ-tocotrienol (DT3) have drawn large attention due to their efficacy as radioprotective agents. α-TOS has been shown to act superior to α-tocopherol (α-TOH) in mice by reducing lethality following total body irradiation (TBI). Because α-TOS has been shown to act superior to α-tocopherol (α-TOH) in mice by reducing lethality following total body irradiation (TBI), we hypothesized succinate may be contribute to the radioprotection of α-TOS. To study the contributions of succinate and to identify stronger radioprotective agents, we synthesized α-, γ- and δ-TOS. Then, we evaluated their radioprotective effects and researched further mechanism of δ-TOS on hematological recovery post-irradiation. Our results demonstrated that the chemical group of succinate enhanced the effects of α-, γ- and δ-TOS upon radioprotection and granulocyte colony-stimulating factor (G-CSF) induction, and found δ-TOS a higher radioprotective efficacy at a lower dosage. We further found that treatment with δ-TOS ameliorated radiation-induced pancytopenia, augmenting cellular recovery in bone marrow and the colony forming ability of bone marrow cells in sublethal irradiated mice, thus promoting hematopoietic stem and progenitor cell recovery following irradiation exposure. δ-TOS appears to be an attractive radiation countermeasure without known toxicity, but further exploratory efficacy studies are still required.

[Therapeutic Effect of Recombinant Human Stem Cell Factor on Rhesus Monkeys with Severe Acute Radiation Sickness].

OBJECTIVE: To study the therapeutic effect of rhSCF early administration on rhesus monkeys with severe acute radiation sickness(ARS). METHODS: Twelve adult monkeys totally exposed to 7.0 Gy 60Co were divided into radiation control and SCF groups, and monkeys in SCF group were subcutaneously injected recombinant human SCF(rhSCF) 200 µg/kg at half an hour and 24 hour after irradiation, while the radiation control monkeys were injected physiological saline. Survival was monitored and hematopoiesis was evaluated at 40 days following early treatment. RESULTS: 6 animals treated with rhSCF all survived, while 2 in irradiated controls survived on 40 day after radiation. rhSCF treatment promoted hematopoiesis recovery significantly, increased the nadir of white blood cells, neutrophils and platelets, and simplified supportive care in ARS rhesus monkeys. CONCLUSION: RhSCF injection soon after TBI taken shows an significant therapeutic efficiency on rhesus monkeys with severe acute radiation sickness.

[Therapeutic Effect of Combined Cytokines on Nonhuman Primate Model of Severe Haemopoietic Acute Radiation Sickness].

OBJECTIVE: To evaluate the therapeutic effects of combined administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF), recombinant human thrombopoietin (rhTPO) and recombinant human interleukin-2 (rhIL-2) on radiation-induced severe haemopoietic acute radiation sickness (ARS) in rhesus monkeys, so as to provide experimental evidences for the effective clinical treatment. METHODS: Seventeen rhesus monkeys were exposed to 7.0 Gy (60)Co γ-ray total body irradiation (TBI) to establish severe haemopoietic ARS model, and were randomly divided into supportive care group, rhG-CSF+rhTPO treatment group and rhG-CSF+rhTPO+rhIL-2 treatment group. Survival time, general signs such as bleeding and infections, and peripheral blood cell counts in each group were monitored. Bone marrow cells were cultivated to examine the colony formation ability. The histomorphology changes of bone marrow were observed at 45 d post irradiation. RESULTS: After 7.0 Gy (60)Co γ-ray TBI, monkeys of supportive care group underwent tarry stool and emesis, then died in 12~18 d. The overall survival rate in this group was 16.7%. Gastrointestinal reactions of monkeys in two combined-cytokines treatment groups were inapparent. Combined-cytokines treatment induced 100% survival. Complete blood cells declined sharply after irradiation in each group, but two combined-cytokines treatment schemes could elevate the nadir of all blood cells, shorten the duration of pancytopenia and accelerate the recovery of hemogram. Compared with rhG-CSF+ rhTPO treatment, rhG-CSF+ rhTPO+ rhIL-2 treatment could increase the counts of lymphocytes and monocytes. The colony-formation rate of haemopoietic stem/progenitor cells in bone marrow dropped markedly at 2 d after irradiation. Combined-cytokines treatment promoted the ability of colony formation on day 29. Hematopoietic cells mostly disappeared in bone marrow of animals in supportive care group, but hematopoietic functions were recovered after cytokines were administrated. CONCLUSION: rhG-CSF+ rhTPO and rhG-CSF+ rhTPO+ rhIL-2 treatment can significantly promote hematopoiesis recovery, improve the quantity of life, simplify the supportive therapy, and enhance the survival rate of rhesus monkeys with severe haemopoietic ARS induced by 7.0 Gy (60)Co γ-ray exposure. Especially the application of rhIL-2 can accelerate the recovery of lymphocytes and monocytes and restore the immunological function. Thus, combination of rhG-CSF, rhTPO and rhIL-2 on the basis of supportive care is an efficient strategy to treat severe haemopoietic ARS.

Natural Product Vibsanin A Induces Differentiation of Myeloid Leukemia Cells through PKC Activation.

All-trans retinoic acid (ATRA)-based cell differentiation therapy has been successful in treating acute promyelocytic leukemia, a unique subtype of acute myeloid leukemia (AML). However, other subtypes of AML display resistance to ATRA-based treatment. In this study, we screened natural, plant-derived vibsane-type diterpenoids for their ability to induce differentiation of myeloid leukemia cells, discovering that vibsanin A potently induced differentiation of AML cell lines and primary blasts. The differentiation-inducing activity of vibsanin A was mediated through direct interaction with and activation of protein kinase C (PKC). Consistent with these findings, pharmacological blockade of PKC activity suppressed vibsanin A-induced differentiation. Mechanistically, vibsanin A-mediated activation of PKC led to induction of the ERK pathway and decreased c-Myc expression. In mouse xenograft models of AML, vibsanin A administration prolonged host survival and inhibited PKC-mediated inflammatory responses correlated with promotion of skin tumors in mice. Collectively, our results offer a preclinical proof of concept for vibsanin A as a myeloid differentiation-inducing compound, with potential application as an antileukemic agent. Cancer Res; 76(9); 2698-709. ©2016 AACR.

[Studies on peripheral blood & pathological index in inflammatory bowel disease of rats with clyster No. 1].

OBJECTIVE: To observe the effect of the clysters No. 1 of Traditional Chinese Medicine (TCM) in inflammatory bowel disease on rats and search the new way and evidence for IBD cures. METHOD: The rats were divided into four groups: normal control group (I), model control group (II), Sulfasalazine( SASP) treating control group (III) and traditional Chinese medicine clysters No. 1 group (IV). There were 20 rats per group. Trinitrobenzenesulfonic Acid was used to induce the experimental models. The WBC, RBC, platelets of peripheral blood were monitored. The animals are put to death by dislocation in 4, 7, 14 and 21 d after giving the medicine respectively. The pathological changes of the intestines were observed in different times. RESULT: Compared with group II, the counting of platelets of group IV got rise in seventh day after administration, as of well as the group III. There were no statistical differences in WBC and RBC, compared with group II after the medicine administration for two weeks. There was no witness in effect of SASP for IBD on rats on organize pathology in this experiment. The enema No.1 lightened pathological injure and promoted the effect of restoration of IBD on rats obviously. CONCLUSION: The TCM enema No. 1 has anti-IBD activities on inflammatory bowel disease in rats. The foundation is established that the IBD cure on clinic and the basis have been provided the action mechanism of Chinese medicine which is utilized to IBD further.

[Effects of Different Dose of Cyclophosphamide on Peripheral Blood Cells of Normal ICR Mice].

OBJECTIVE: To investigate effective doses of cyclophosphamide (CTX) for establishment of leukopenia model in ICR mouse. METHODS: Normal ICR mice (n = 96) were divided into CTX(80), CTX(100), CTX(120), CTX(150) and CTX(300) groups, of which mice received CTX intraperitoneally at a dose of 80, 100, 120, or 150 mg/kg once a day for 3 consecutive days, or 300 mg/kg with single injection. The peripheral blood cell counts were detected at various times before and after CTX administration. RESULTS: The peripheral white blood cell nadirs in the mice injected with CTX appeared on day 4 after the first dose of CTX. The peripheral white blood cell nadir in group CTX(100) was 26.7% of the value measured in mice before CTX administrated, and that of group CTX(80) was 35.0%. Higher doses of CTX, however, caused too severity in hematopoietic injury. CONCLUSION: The dose of CTX 100 mg/(kg·d) × 3d is appropriate for leucopenia model of ICR mouse.

[Effects of HS 6101 and rhG-CSF on Hematopoiesis Recovery of ICR Mice Injured by Cyclophosphamide].

OBJECTIVE: To investigate the effects of HS 6101 and recombinant human granulocyte colony stimulating factor (rhG-CSF) on hematopoiesis recovery of ICR mice injured by cyclophosphamide (CTX). METHODS: A total of 103 ICR mice were divided into 4 groups, including CTX control (46 mice), HS 6101 (21 mice), rhG-CSF (18 mice) and HS 6101+rhG-CSF (18 mice), respectively. The mouse model of chemotherapy-induced haematopoietic injury was established by CTX intraperitoneal injection at a dose of 100 mg/kg once a day for 3 consecutive days. Single dose of HS 6101 (27 µg/mouse) was injected subcutaneously at 1 hour before the first administration of CTX. One day after the last CTX treatment, 2 µg/mouse of rhG-CSF was injected subcutaneously once a day for 5 consecutive days. The peripheral blood cell counts of the mice were observed once every 2 days. Hematopoietic progenitor cell colony counting and histopathological assessment of bone marrow cells were evaluated in the mice at days 4 and 9 after the first administration of CTX. RESULTS: Both HS 6101 and rhG-CSF alone or in combination, significantly elevated the nadirs of peripheral blood leukocytes and neutrophils, increased the number of bone marrow hematopoietic progenitor cells, and stimulated the hematopoietic cell hyperplasia of bone marrow in the mice treated with CTX. The effect of HS 6101 combined with rhG-CSF was better than that of the drugs used alone. CONCLUSION: The HS 6101 at 27 µg/mouse can significantly promote the recovery of hematopoiesis in ICR mice treated with CTX chemotherapy, and its combination with rhG-CSF shows synergistic effects.