Urotensin II activates the ferroptosis pathway through circ0004372/miR-124/SERTAD4 to promote the activation of vascular adventitial fibroblasts.

Both vascular adventitial fibroblasts (VAFs) and urotensin II (UII) play important roles in vascular remodeling diseases, but the mechanism of UII in VAFs is still unclear. UII inhibited miR-124 expression through up-regulating circ0004372 expression, thereby promoting SERTAD4 expression. UII significantly promoted the generation of ROS, MDA and 4-HNE, reduced the activities of SOD, GST and GR, increased Fe2+ concentration and inhibited GPX4 expression through circ0004372/miR-124/SERTAD4. Both UII and ferroptosis inducer Erastin significantly promoted the expression of α-SMA, Collagen I and TGF-ß1 in VAFs, but circ0004372 siRNA, miR-124 mimics, SERTAD4 siRNA or Ferrostatin-1 significantly inhibited the effect of UII and Erastin on cell activation. When co-transfected with circ0004372 siRNA and miR-124 inhibitors or miR-124 mimics and SERTAD4 overexpression vector, UII still significantly increased the expression of α-SMA, Collagen I and TGF-ß1. After transfection with circ0004372 overexpression vector, miR-124 inhibitors or SERTAD4 overexpression vector and then treating with UII and Ferrostatin-1, the expression of α-SMA, Collagen I and TGF-ß1 was still significant; when the circ0004372 overexpression vector and miR-124 mimics or miR-124 inhibitors and SERTAD4 siRNA were co-transfected and then UII and Ferrostatin-1 were added, the expression of α-SMA, Collagen I and TGF-ß1 was not significantly increased. Therefore, these results indicate that UII promotes the activation of VAFs through the circ0004372/miR-124/SERTAD4/ferroptosis pathway.

A phase 1b/2 study of PF-06747775 as monotherapy or in combination with Palbociclib in patients with epidermal growth factor receptor mutant advanced non-small cell lung cancer.

INTRODUCTION: This Phase 1/2 study (NCT02349633) explored the safety and antitumor activity of PF-06747775 (oral, third-generation epidermal growth factor receptor [EGFR] tyrosine kinase inhibitor) in patients with advanced non-small cell lung cancer after progression on an EGFR inhibitor. METHODS: Phase 1 was a dose-escalation study of PF-06747775 monotherapy (starting dose: 25 mg once daily [QD]). Phase 1b/2 evaluated PF-06747775 monotherapy at recommended Phase 2 dose (RP2D; Cohort 1); PF-06747775 200 mg QD plus palbociclib (starting dose: 100 mg QD orally; Cohort 2A); and PF-06747775 monotherapy at RP2D in a Japanese lead-in cohort. RESULTS: Sixty-five patients were treated. Median treatment duration was 40.1 weeks. Monotherapy maximum tolerated dose was not determined. Two patients in Cohort 2A had dose-limiting toxicities. The monotherapy RP2D was estimated to be 200 mg QD. Most frequently reported adverse events (AEs) were diarrhea (69.2%), paronychia (69.2%), and rash (60.0%). Most AEs were grades 1-3. Overall, objective response rate (90% confidence interval [CI]) was 41.5% (31.2-52.5%). Median (range) duration of response was 11.09 (2.70-34.57) months. Median progression-free survival (90% CI) was 8.1 (5.4-23.3) months. CONCLUSIONS: PF-06747775 had a manageable safety profile and the study design highlights important considerations for future anti-EGFR agent development.

Glutamine switches vascular smooth muscle cells to synthetic phenotype through inhibiting miR-143 expression and upregulating THY1 expression.

AIMS: Vascular smooth muscle cells (VSMCs) are involved in the pathogenesis of many human cardiovascular diseases. They modulate their phenotype from "contractile" to "synthetic" in response to changes in local environmental cues. How glutamine regulates the differentiation of VSMCs and the underlying mechanisms remain largely unknown. MAIN METHODS: Here, we explored the effects of various doses of glutamine (0 mM, 1 mM, 2 mM, and 4 mM) on the proliferation, migration, and phenotypic switch of human VSMCs in vitro. Glutamine dose-dependently enhanced VSMC proliferation, and markedly increased VSMC migration. KEY FINDINGS: Notably, glutamine promoted the phenotypic switch of VSMCs towards a synthetic phenotype, as evidenced by significantly decreased expression of contractile markers myosin heavy chain 11 (MYH11) and calponin while increased expression of synthetic markers collagen I and vimentin. Importantly, these changes upon glutamine treatments were attenuated after additional treatments with glutamine metabolism inhibitor BPTES. Additionally, glutamine downregulated miR-143 expression, and miR-143 inactivation alone resulted in enhanced proliferation, migration, and promoted the synthetic phenotype of VSMCs. Moreover, Thy-1 cell surface antigen (THY1) was validated as a downstream target of miR-143, and THY1 expression was upregulated by glutamine in VSMCs. Furthermore, either miR-143 overexpression or THY1 silencing abolished the effect of glutamine on proliferation, migration, and phenotypic switch of VSMCs, supporting a novel glutamine-miR-143-THY1 pathway in modulating VSMC functions. SIGNIFICANCE: This study demonstrated a novel mechanism of glutamine in modulation of VSMC phenotypic switch by targeting miR-143 and THY1, and provides significant insight on targeted therapy of patients with cardiovascular diseases.

Tanshinone IIA attenuates high glucose induced human VSMC proliferation and migration through miR-21-5p-mediated tropomyosin 1 downregulation.

The proliferation and migration of vascular smooth muscle cells (VSMCs) play important roles in the development and progression of diabetes-related vascular complications. Recently, microRNAs (miRNAs) have been suggested to be involved in the pathogenesis of vascular diseases. This study was designed to investigate the influences of tanshinone IIA, an active compound extracted from Chinese herb Salvia miltiorrhiza, on the proliferation and migration of human aortic VSMCs (HASMCs). cultured in a high glucose medium and the underlying mechanisms related miRNAs. Using a miRNA microarray method, we profiled the miRNA expression signature in human aortic VSMCs (HASMCs) exposed to normal glucose, high glucose with and without Tanshinone IIA. Cell proliferation was measured with 5-bromo-2'-deoxyuridine (BrdU) incorporation assay. Cell migration was evaluated using transwell migration assay and wound scratch assay. Western blot was used to examine the expression of tropomyosin 1 (TPM1) and miRNA level was quantified by real-time PCR. The results showed that several miRNAs that were highly expressed in the high glucose group were significantly decreased in the high glucose with Tanshinone IIA group compared with the normal glucose group (P < 0.05). Among these miRNAs, miR-21-5p was significantly upregulated in the high glucose group and downregulated after Tanshinone IIA treatment (P < 0.05). The depletion of miR-21-5p in HASMCs resulted in decreased cell proliferation and migration (P < 0.05). Moreover, we found that Tanshinone IIA inhibited proliferation and migration partly through miR-21-5p-mediated TPM1 downregulation (P < 0.05). In conclusion, the present study demonstrates that Tanshinone IIA is able to protect HASMCs from high glucose-induced proliferation and migration through regulating expression of miRNAs.

Factors Affecting the Dissolution of Indomethacin Solid Dispersions.

The aim of this study was to investigate the influence of factors such as carrier type, drug/carrier ratio, binary carriers, and preparation method on the dissolution of an insoluble drug, indomethacin (IM), under supersaturation conditions. Using a solvent evaporation (SE) method, poloxamer 188 and PVP K30 showed better dissolution among the selected carriers. Furthermore, as the ratio of carriers increased (drug/carrier ratio from 1:0.5 to 1:2), the dissolution rate increased especially in almost two times poloxamer 188 solid dispersions (SDs), while the reverse results were observed for PVP K30 SDs. For the binary carrier SD, a lower dissolution was found. Under hot melt extrusion (HME), the dissolution of poloxamer 188 SD and PVP K30 SD was 0.83- and 0.94-folds lower than that using SE, respectively, while the binary carrier SD showed the best dissolution. For poloxamer 188 SDs, the drug's crystal form changed when using SE, while no crystal form change was observed using HME. IM was amorphous in PVP K30 SDs prepared by both methods. For binary carrier systems, amorphous and crystalline drugs coexisted in SD using SE, and negligible amorphous IM was in SD using HME. This study indicated that a higher amorphous proportion in SD did not correlate with higher dissolution rate, and other factors, such as carrier type, particle size, and density, were also critical.

Geraniin induces apoptosis of human breast cancer cells MCF-7 via ROS-mediated stimulation of p38 MAPK.

Geraniin, a typical ellagitannin isolated from Phyllanthus urinaria Linn, has been found to possess a range of bioactive properties. In the present study, we found that Geraniin showed potent anti-proliferative effects on human breast cancer MCF-7 cells. The IC50 values were 9.94, 17.98 and 42.32 µM after 72-, 48- and 24-h treatment, respectively. Meanwhile, Geraniin could remarkably disrupt mitochondrial membrane potential and arrest S phase cell cycle. Western-blot analysis showed that Geraniin induced phosphorylation of the anti-apoptotic Bcl-2, and the cleavage of poly (ADP-ribose) polymerase (PARP) and caspase-3 in MCF-7 cells. Moreover, Geraniin treatment activated p38 mitogen-activated protein kinase (p38 MAPK) and the effect was blunted in MCF-7 cells with the treatment of a specific p38 inhibitor SB203580. Geraniin could generate intracellular reactive oxygen species (ROS), activate p38 MAPK then induce the apoptosis in MCF-7 cells, such phenomena was abrogated by pretreatment with N-acetyl-l-cysteine. In general, these results support the conclusion that Geraniin-induced apoptosis is mediated via ROS-mediated stimulation of p38 MAPK signaling.

Geraniin exerts cytoprotective effect against cellular oxidative stress by upregulation of Nrf2-mediated antioxidant enzyme expression via PI3K/AKT and ERK1/2 pathway.

BACKGROUND: Geraniin, an active compound with remarkable antioxidant activity, was isolated from Geranium sibiricum. The present study aimed to investigate whether geraniin has the ability to activate Nrf2, induce antioxidant enzyme expression and protect cells from oxidative damage. METHODS: The cells were pretreated with geraniin for 24h and exposed to hydrogen peroxide (H2O2) for 4h. Intracellular reactive oxygen species (ROS) levels, mitochondrial membrane potential and apoptosis were measured. We also investigated intracellular glutathione (GSH) levels and changes in nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated signaling cascade in cells treated with geraniin. RESULTS: We investigated the protective effects of geraniin against H2O2-induced apoptosis in HepG2 cells. Geraniin significantly reduced H2O2-induced oxidative damage in a dose dependent manner. Further, geraniin induced the expression of heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase-1 (NQO1) and level of glutathione (GSH) in a concentration- and time-dependent manner, and increased Nrf2 nuclear translocation. The Nrf2-related cytoprotective effects of geraniin were PI3K/AKT and extracellular signal-regulated protein kinase1/2 (ERK1/2) pathway-dependent. However, inhibitors of PI3K/AKT and ERK1/2 (LY294002 or U0126) not only suppressed geraniin-induced nuclear translocation of Nrf2 but also abolished the expression of HO-1, NQO1 and GSH. CONCLUSIONS: These results demonstrated that geraniin induced Nrf2-mediated expression of antioxidant enzymes HO-1 and NQO1, presumably via PI3K/AKT and ERK1/2 signaling pathways, thereby protecting cells from H2O2-induced oxidative cell death. GENERAL SIGNIFICANCE: Geraniin, at least in part, offers an antioxidant defense capacity to protect cells from the oxidative stress-related diseases.

Clinical and Prognostic Significance of Coagulation Assays in Pancreatic Cancer Patients With Absence of Venous Thromboembolism.

OBJECTIVES: Activation of coagulation and fibrinolysis is frequently observed in patients with cancer, even with absence of thrombosis. Furthermore, plasma coagulation parameters were associated with tumor progression, metastasis, and prognosis. Few studies have investigated these associations in pancreatic cancer (PA). This study aimed to investigate the clinical and prognostic significance of various plasma coagulation tests in PA patients with absence of venous thromboembolism (VTE). MATERIALS AND METHODS: A total of 139 PA patients with the absence of VTE were included in the analysis. Patients were followed up for at least 12 months until death. Pretreatment coagulation parameters including prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (F), antithrombin-III (AT-III), protein C (PC), factor-VIII (F-VIII), and D-dimer (DD) were evaluated. A total of 40 age-matched and sex-matched healthy individuals without coagulation disorder were enrolled as the control group. RESULTS: Patients were inclined to have higher levels of PT, INR, APTT, F, F-VIII, and DD and lower levels of AT-III and PC than the control group (P<0.01 for all, except P=0.022 for INR and P=0.015 for AT-III). Patients with advanced tumor stages were likely to have higher median DD levels and lower AT-III levels than the control group (P=0.005 and P<0.001, respectively). DD levels were higher in patients with advanced pathology grade (P<0.001). Plasma DD levels (hazards ratio=1.71; 95% confidence interval, 1.07-2.73; P=0.025) were identified as the significantly independent prognostic predictors. CONCLUSIONS: PA patients are susceptible to activation of hemostasis system. Pretreatment plasma DD level was a potential predictor of prognosis in PA patients without VTE.

Chimaphilin induces apoptosis in human breast cancer MCF-7 cells through a ROS-mediated mitochondrial pathway.

Chimaphilin, 2,7-dimethyl-1,4-naphthoquinone, is extracted from pyrola [Passiflora incarnata Fisch.]. In this study, the anticancer activity and underlying mechanisms of chimaphilin toward human breast cancer MCF-7 cells are firstly investigated. Chimaphilin could inhibit the viability of MCF-7 cells in a concentration-dependent manner, and the IC50 value was 43.30µM for 24h. Chimaphilin markedly induced apoptosis through the investigation of characteristic apoptotic morphological changes, nuclear DNA fragmentation, annexin V-FITC/propidium iodide (PI) double staining. Flow cytometry assay revealed that chimaphilin triggered a significant generation of ROS and disruption of mitochondrial membrane potential. Additionally, western blotting assay showed that chimaphilin suppressed Bcl-2 level and enhanced Bad level, then activated caspase-9 and caspase-3, and further activated the poly ADP-ribose polymerase (PARP), finally induced cell apoptosis involving the mitochondrial pathway. Furthermore, free radical scavengers N-acetyl-L-cysteine (NAC) pretreatment test testified that chimaphilin could increase the generation of ROS, then induce cell apoptosis. In general, the present results demonstrated that chimaphilin induced apoptosis in human breast cancer MCF-7 cells via a ROS-mediated mitochondrial pathway.

Expressions of cyclin B1 and p21cipl in adult acute leukemia and their correlation.

Cyclin B1, a positive regulator, controls mitosis occurrence, plays an important role in cell proliferation. To investigate the clinical significance of cyclin B1, the expression of cyclin B1 in acute leukemia (AL) patients was measured; the expression of cyclin B1 and p21(cipl), and their cell cycle distribution were assayed by flow cytometry in 136 adult patients with newly diagnosed AL, 10 continuous complete remission (CCR) AL and 17 normal controls; the mRNA of cyclin B1 and p21(cipl), and the proliferation cell nuclear antigen (PCNA) in patients and normal controls were detected with semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). The results showed that the expression of cyclin B1 in newly diagnosed AL patients was significantly higher than that in normal controls. For the relapsed AL patients, the cyclin B1 expression was also higher than that in normal controls, but lower than that in newly diagnosed cases, there was no significant difference between the remission cases and normal controls, nor difference between CCR AL patients and normal controls. All patients with high cyclin B1 expression had an unscheduled expression manner, that cyclin B1 protein appeared in G(1) phase, and in some case it even higher than that of G(2) phase. The response rate (partial remission + complete remission) and survival rate in the cyclin B1 high expressed patients were higher than that of cyclin B1 low expressed patients. The relapse rate in cyclin B1 high expressed patients was higher than that in cyclin B1 normally expressed patients. The survival rate in cyclin B1 high expressed patients was higher than that in cyclin B1 low expression patients. A negative correlation between the expression of cyclin B1 and p21(cipl) was observed. Additionally, cyclin B1 protein expression was generally correlated with proliferation index (PI) and proliferation cell nuclear antigen (PCNA). It is concluded that this study demonstrates for the first time cyclin B1 overexpression and abnormally distribution in cell cyclin of newly diagnosed AL patients. It was considered that cyclin B1 may play an important role in leukemic pathogeneses and can be one of the factors influencing the prognosis of AL patients.

[Synergetic cytotoxicity of cisplatin and etoposide to leukemia cell line K562 and its mechanism].

BACKGROUND & OBJECTIVE: Etoposide (VP-16) is one of the most common chemotherapy drugs, but its usage is limited by drug resistance. Some researches on solid tumors show that cisplatin (DDP) have synergetic effect with VP-16. This study was to evaluate synergetic cytotoxicity of VP-16 and DDP to leukemia cell line K562, and explore the mechanism. METHODS: K562 cells were treated with VP-16 (0 or 5 microg/ml) and DDP (0, 0.3, 3, 15, or 30 microg/ml) in different combination patterns. Inhibitory effect of VP-16 and DDP on survival of K562 cells was measured by MTT assay. Cell apoptosis was evaluated by AO/EB double fluorescent labeling. The expression of topoisomerase (TOPO) II alpha and II beta, and transcription factor Sp1 and Sp3 were measured by semi-quantitive reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. RESULTS: MTT assay showed significant synergetic cytotoxicity of VP-16 and DDP. VP-16 in combination with DDP obviously enhanced cell apoptosis. RT-PCR showed that DDP significantly up-regulated the expression of TOPO II and Sp1 in concentration-dependent manners (TOPO II alpha, II beta, and Sp1 were up-regulated by 36%, 25%, and 75% of control, respectively, when treated with 30 microg/ml of DDP), and down-regulated Sp3 by 49% of control; VP-16 (5 microg/ml) down-regulated TOPO II alpha by 71.9%, and up-regulated Sp3 by 14%; VP-16 (5 microg/ml) in combination with DDP (30 microg/ml) up-regulated TOPO II alpha by 83%, II beta by 11%, and Sp1 by 58% when compared with using VP-16 alone (but the levels were lower than using DDP alone), and down-regulated Sp3 by 61.3% when compared with using DDP alone. Western blot showed similar results to RT-PCR. CONCLUSION: Through up-regulating TOPO II, DDP could enhance the chemotherapeutic effect of VP-16 on K562 cells by provide more target enzyme to act on.

[The clinical significance of cyclin B1 expression in adult acute leukemia patients].

OBJECTIVE: To investigate the clinical significance of cyclin B1 expression in adult acute leukemia (AL) patients. METHODS: The expression of cyclin B1 and p21 and their cell cycle distribution were measured by flow cytometry in 85 adult patients with de novo AL, 10 continuous complete remission (CCR) AL and 17 normal controls (NC). The mRNAs of cyclin B1, p21 cip1 and proliferation cell nuclear antigen (PCNA) in patients and NCs were measured with semi-quantity reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Cyclin B1 protein expression in de novo AL patients was significantly higher than that in NC (P < 0.001). It was higher in relapsed patients than in NC (P < 0.05) but was lower than in de novo AL (P < 0.01). There was no difference between the remission cases and NC (P = 0.21), and between CCR patients and NC (P > 0.05). The cyclin B1 overexpression ratio was higher than that of NC. A negative correlation between the expression levels of cyclin B1 and P21 was observed (r = -0.266, P < 0.05). The cyclin B1 protein expression level was positively correlated with its mRNA level. The expression of cyclin B1 was positively correlated with proliferation index (PI) levels, and with PCNA levels (rPI = 0.7314, rPCNA = 0.7152). Remission rate was higher in high cyclin B1 expression patients than in normal cyclin B1 expression patients (P < 0.01), so did the relapse rate (P < 0.01). Patients with higher cyclin B1 expression had higher survival rate. CONCLUSION: Cyclin B1 was overexpressed and abnormally distributed in cell cycle phases in de novo AL patients. Overexpression of cyclin B1 might be a favorable prognostic factor for patients with AL.

[Expression of cyclin A in adult patients with acute leukemia].

OBJECTIVE: To investigate the clinical significance of cyclin A expression in adult patients with acute leukemia (AL). METHODS: 4 ml bone marrow was extracted from 100 AL patients and 10 normal controls to isolate the mononuclear cells (MNCs). The cyclin A mRNA levels in these MNCs were measured by RT-PCR. The cyclin A protein level and cell cycle in 75 randomly selected AL patients and 10 normal controls were examined by flow cytometric analysis. RESULTS: (1) The distribution of cyclin A protein was normal in cell cycle in AL patients. The positive rates of cyclin A protein and mRNA were 66.7% and 59%, significantly higher than those in the normal controls (0 and 1.4% respectively, both P < 0.01). The median expression levels of cyclin A protein and mRNA of cyclin A in AL patients were 18.5% and 0.539 +/- 0.490 respectively, significantly higher than those in the normal controls (both P < 0.01). Sequence analysis showed a complete consistency between the positive segment of cyclin A and the objective gene in GeneBank. (2) The levels of cyclin A protein and mRNA were positively correlated with the cumulative percentages of cells in S and G(2)/M phases (P < 0.01). (3) The expression level of cyclin A protein in the recurrent acute lymphoblastic leukemia (ALL) group was 15.4%, significantly lower than those of de novo group (29.5%, t = 14.418, P = 0.022). (4) The complete remission (CR) rates in the AL patients with high expression levels of cyclin A protein and mRNA group were 87.9% and 85.7% respectively, significantly higher than those in the AL patients with low expression levels (38.2% and 53.5% respectively, both P < 0.01). Multivariate regression analysis showed that cyclin A was one of the influencing factors of CR rate of AL patients (P < 0.05). CONCLUSION: Cyclin A expression contributes to the high proliferative activity in leukemia cells. The abnormal expression of cyclin A might be a prognostic marker of CR rate in AL patients.

[The relationship between cyclin B1 and multidrug resistance in adult patients with acute leukemia].

OBJECTIVE: To investigate the relation between the expression of cyclin B1 and multidrug resistance in adult patients with acute leukemia. METHODS: The proteins expression of cyclin B1, p170 was measured with flow cytometric analysis in 85 adult de novo acute leukemia patients (AL) and 17 normal control (NC). The expression of cyclin B1, multidrug resistance gene (mdr-1), topoisomerase IIalpha, beta (TOPOIIalpha, beta) and bcl-2 mRNA in these patients was measured with semi-quantify reverse transcription polymerase chain reaction (RT-PCR). RESULTS: (1) The expression of cyclin B1 protein (M = 12.3%) and mRNA (M = 0.217) in the treatment resistance group was significantly lower than the sensitive group cyclin B1 protein (M = 22.7%) and mRNA (M = 0.563) (P < 0.05), so was the mRNA of TOPOIIalpha (M = 0.236), TOPOIIbeta (M = 0.328) than the sensitive group TOPOIIalpha (M = 0.514), TOPOIIbeta (M = 0.635) (P < 0.01). Cyclin B1 protein expression was lower than 5% and there were no expression of cyclin B1, TOPOIIalpha, mdr-1 mRNA in the NC group under the same condition. (2) The p170 protein (M = 14.3%) and mdr-1 (M = 1.071), bcl-2 (M = 0.941) mRNA expression in the resistant group was significant higher than the sensitive group p170 protein (M = 3.6%) and mdr-1 (M = 0.094), bcl-2 (M = 0.153) (P < 0.01). (3) The expression of cyclin B1 protein and TOPOIIalpha, TOPOIIbeta mRNA was positive correlated (r(TOPOIIalpha) = 0.472, P < 0.01; r(TOPOIIbeta) = 0.683, P < 0.01), so was the cyclin B1 mRNA (r(TOPOIIalpha) = 0.319, P < 0.05; r(TOPOIIbeta) = 0.527, P < 0.05). (4) There was no correlation between cyclin B1 and p170, mdr-1, bcl-2. (5) By Binary logistic forward conditional analysis we concluded that cyclin B1 correlated with atypital mutidrug resistance. CONCLUSIONS: Low expression of cyclin B1 might be a unfavorable prognostic factor for patients with AL and measurement of both cyclin B1 and TOPOIIalpha, TOPOIIbeta gene expression would predict drug resistance in adult acute leukemia patients.

[Effects of aminophylline on proliferation and apoptosis in Raji lympho-blastoid cell line].

The aim of this study was to investigate whether and how phosphodiesterase (PDE) inhibitors modulate the proliferation, cell cycle and apoptosis in lymphoma cells. The effects of aminophylline (AM), a non-specific PDE inhibitor, on Raji cells were explored in vitro. MTT assay, light and transmission electron microscopy and annexin V staining were used to observe cell proliferation, morphologic changes and apoptosis rate in AM-treated cells, and FCM and RT-PCR techniques were adopted to detect the effect on cell cycle, the expression of cyclin B1 and Bcl-2 and mitochondrial transmembrane potential in AM-treated cells. The results showed that AM inhibited the growth of Raji cells in a concentration-dependent manner. Morphologic observations showed apoptosis changes in AM-treated cells, including cytoplamic shrinkage, cytoplasmic bubbling, karyopyknosis and nuclear fragmentation. FCM and RT-PCR detection showed that AM intervention increased the fraction of annexin V(+) cells, reduced the value of mitochondrial transmembrane potential, induced S phase arrest, and down-regulated the expression of Bcl-2 at both mRNA and protein level and cyclin B1 protein in a concentration-dependent manner. It is concluded that PDE inhibitor aminophylline may induce Raji cell growth inhibition, S phase arrest, apoptosis via down-regulation of Bcl-2 and reduction of mitochondrial transmembrane potential.

[Effects of sodium orthovanadate on proliferation and apoptosis in raji cells and its mechanism].

In order to investigate the role and the mechanism of protein tyrosine phosphatase (PTPase) signaling pathway in the regulation of proliferation, cell cycle and apoptosis in lymphoma cells, the effects of sodium orthovanadate, Na(3)VO(4), a specific PTPase inhibitor, were explored on Raji lymphoblast-like cell line by MTT assay and CFU-Raji culture, morphologic observation, DNA gel electrophoresis, FCM and RT-PCR. Results showed that MTT assay and CFU-Raji culture demonstrated that sodium or thovanadate inhibited the growth of Raji cells in a concentration-dependent fashion; morphologic observations showed that Raji cells exhibited cytoplasm shrinkage, cytoplasm membrane blebbing, nuclear fragmentation and chromatin condensation forming crescents along nuclear membrane characteristic of apoptosis in the presence of Na(3)VO(4); DNA gel electrophoresis revealed typical DNA ladder reminiscent of DNA cleavage at internucleosomal sites in Na(3)VO(4) treated cells; FCM and RT-PCR indicated that Na(3)VO(4) intervention increased the fraction of annexin V(+) PI(-) cells, reduced the value of mitochondrial transmembrane potential, induced G(2)/M arrest and down-regulated the expression of Bcl-2 and cyclin B1 at both mRNA and protein level in a concentration-dependent manner. It was concluded that PTPase pathway might be implicated in the regulation of cell proliferation, cell cycle and apoptosis, and PTPase specific inhibitor Na(3)VO(4) could induce Raji cell growth inhibition, G(2)/M arrest and apoptosis via down-regulation of Bcl-2 and cyclin B1, and reduction of mitochondrial transmembrane potential.