[Relationship between TET2 Gene SNP rs3733609 C/T and JAK2V617F Allele Burden in Patients with Myeloproliferative Neoplasms].

OBJECTIVE: To investigate the relationship between the polymorphism of TET2 gene SNP rs3733609 and JAK2V617F allele burden in patients with myeloproliferative neoplasms (MPN). METHODS: The exon 9 of TET2 gene was amplified by RT-PCR, and the nucleotide sequence of SNP rs3733609 site was analyzed by gene sequencing. The MGB Taqman probe PCR method was used to detect the JAK2V617F allele burden. The correlation of TET2 gene SNP rs3733609 C/T with the JAK2V617F allele burden and clinical parameters was analyzed. RESULTS: TET2 gene rs3733609 C/T heterozygosity (normal T/T) could be detected in 19 cases of 85 cases of JAK2V617F positive MPN (22.4%) patients, while the TET2 gene rs3733609 C/T heterozygosity could be detected only in 9 of the 106 healthy volunteers, and the incidence was only 8.5% (9/106). Compared with the negative group (TET2 rs3733609 T/T), there was no significant difference in the median age, hemoglobin level and platelet count in the patients with TET2 gene SNP rs3733609 (CT/TC) positive, but the WBC count of peripheral blood and JAK2V617F allele burden significantly increased. In JAK2V617F high allele burden group, TET2 gene SNP rs3733609 was positive in 7 cases (36.8%, 7/19), the ratio was higher than that in the low allele burden group(18.2%, 12/66). CONCLUSION: TET2 SNP rs3733609 C/T may be a new susceptible allelee, which affects the clinical characteristics and clonal evolution of MPN patients.

[Expression of Aurora Family Genes in Acute Leukemia and Its Clinical Significance].

OBJECTIVE: To explore the mRNA expression of Aurora-A,B,C(AUR-A,B,C) in acute leukemia(AL) and their correlations with the clinical indications. METHODS: The mRNA expression levels of AUR-A,B,C in 73 cases of newly diagnosed AL (untreated group), 20 cases of AL with remission (remission group) and 14 healthy volunteers as control (healthy group) were detected by QRT-PCR, and the difference of expression levels in difference groups, their correlations with clinical indicators and the correlation between the AUR-A,B,C mRNA expression levels themselves were analyzed. RESULTS: The mRNA expression levels of AUR-A,B,C in untreated group were all higher than those in healthy group and remission group(P<0.01), but there was not significant difference between healthy group and remission group(P>0.05); the mRNA expressions of AUR-A,B,C in acute lymphoblastic leukemia(ALL) group were all significantly higher than that in AML group(P<0.01). The mRNA expression of AUR-A,B,C in high risk group was higher than that in low risk group(P<0.05), but there was no difference in mRNA expression of AUR-A,B,C between high risk group and middle risk group as well as between middle risk group and low risk group(P>0.05). The mRNA expression of AUR-A, B, C in CD34, CD71 and CD56 negative group was not statistically different from that in CD34,CD71 and CD56 positive group(P>0.05). In 73 cases of newly diagnosed AL, the mRNA expression levels of AUR-A, B significantly were positively correlated with lactate dehydrogenase(LDH) level and risk stratification (r=0.279, P=0.017; r=0.314, P=0.007 and r=0.277, P=0.018; r=0.349, P=0.002), while the mRNA expression levels of AUR-A, B were not significantly correlated with age, WBC count, blast ratio in bone marrow at initial diagnosis and remission or no-remission after 1 cours of chemotherapy; the mRNA expression level of AUR-C was significantly positively correlated with WBC count (r=0.263, P=0.025), and LDH level (r=0.348, P=0.003) at initial diagnosis and risk stratificantion(r=0.376, P=0.001), and negatively correlated with age (r=-0.241, P=0.040), and was not significantly correlated with blast ratio in bone marrow at initial diagnosis and remission or noremission after 1 course of chemotherapy. There were significant positive correlations in the mRNA expression between AUR-A and B (r=0.444, P=0.000), AUR-B and C (r=0.763, P=0.000) as well as AUR-A and C (r=0.616, P=0.000). CONCLUSION: Aur-A, B, C mRNA were highly expressed in patients with newly diagnosed AL, moreover the mRNA expression levels of Aur-A,B,C were positively correlated with each other, the high expression of Aur-A, B, C are associated with leukemia types, risk stratification, WBC count and LDH level at initial diagnosis, so they all maybe used as the prognostic markers and potential therapeutic targets.

A TET2 rs3733609 C/T genotype is associated with predisposition to the myeloproliferative neoplasms harboring JAK2(V617F) and confers a proliferative potential on erythroid lineages.

Common germline single-nucleotide polymorphisms (SNPs) at JAK2 locus have been associated with Myeloproliferative neoplasms (MPN). And, the germline sequence variant rs2736100 C in TERT is related to risk of MPN, suggesting a complex association between SNPs and the pathogenesis of MPN. Our previous study (unpublished data) showed that there was a high frequency distribution in rs3733609 C/T genotype at Ten-Eleven Translocation 2 (TET2) locus in one Chinese familial primary myelofibrosis. In the present study, we evaluate the role and clinical significance of rs3733609 C/T genotype in JAK2V617F-positive sporadic MPN (n = 181). TET2 rs3733609 C/T genotype had a higher incidence (13.81%; 25/181) in JAK2V617F-positive sporadic MPN patients than that in normal controls (n = 236) (6.35%; 15/236), which was predisposing to MPN (odds ratio(OR) = 2.361; P = 0.01). MPN patients with rs3733609 C/T genotype had increased leukocyte and platelets counts, elevated hemoglobin concentration in comparison with T/T genotype. Thrombotic events were more common in MPN patients with rs3733609 C/T than those with T/T genotype (P < 0.01). We confirmed that rs3733609 C/T genotype downregulated TET2 mRNA transcription, and the mechanism may be involved in a disruption of the interaction between CCAAT/enhancer binding protein alpha (C/EBPA) and TET2 rs3733609 C/T locus.TET2 rs3733609 C/T genotype stimulated the erythroid hematopoiesis in MPN patients. Altogether, we found a novel hereditary susceptible factor-TET2 rs3733609 C/T variant for the development of MPN, suggesting the variant may be partially responsible for the pathogenesis and accumulation of MPN.

Cytotoxic effect of icaritin and its mechanisms in inducing apoptosis in human burkitt lymphoma cell line.

Icaritin (ICT), a hydrolytic product of icariin from Epimedium genus, exhibits antitumor activities in several human solid-tumor and myeloid leukemia cells with extensive influence on various cell signal molecules, such as MAPKs being involved in cell proliferation and Bcl-2 participating in cell apoptosis. However, the effect of icaritin on Burkitt Lymphoma has not been elucidated. In the present study, we first screened the potential effect of icaritin on Burkitt lymphoma Raji and P3HR-1 cell lines and found that icaritin showed cytotoxicity in both cell lines. We further found that icaritin could significantly inhibit Raji cells proliferation with S-phase arrest of cell cycle and induced cell apoptosis accompanied by activation of caspase-8 and caspase-9 and cleavage of PARP. We also observed that icaritin was able to decrease Bcl-2 levels, thus shifting the Bcl-2/Bax ratio, and it could obviously reduce c-Myc, a specific molecular target in Burkitt lymphoma. Our findings demonstrated that icaritin showed cytotoxicity, inhibited cell growth, caused S arrest, and induced apoptosis in Burkitt lymphoma cells and provided a rationale for the further evaluation of icaritin for Burkitt lymphoma therapy.

Icaritin shows potent anti-leukemia activity on chronic myeloid leukemia in vitro and in vivo by regulating MAPK/ERK/JNK and JAK2/STAT3 /AKT signalings.

PURPOSE: To explore the effects of Icaritin on chronic myeloid leukemia (CML) cells and underlying mechanisms. METHOD: CML cells were incubated with various concentration of Icaritin for 48 hours, the cell proliferation was analyzed by MTT and the apoptosis was assessed with Annexin V and Hoechst 33258 staining. Cell hemoglobinization was determined. Western blotting was used to evaluate the expressions of MAPK/ERK/JNK signal pathway and Jak-2/Phorpho-Stat3/Phorsph-Akt network-related protein. NOD-SCID nude mice were applied to demonstrate the anti-leukemia effect of Icaritin in vivo. RESULTS: Icaritin potently inhibited proliferation of K562 cells (IC50 was 8 µM) and primary CML cells (IC50 was 13.4 µM for CML-CP and 18 µM for CML-BC), induced CML cells apoptosis and promoted the erythroid differentiation of K562 cells with time-dependent manner. Furthermore, Icaritin was able to suppress the growth of primary CD34+ leukemia cells (CML) and Imatinib-resistant cells, and to induce apoptosis. In mouse leukemia model, Icaritin could prolong lifespan of NOD-SCID nude mice inoculated with K562 cells as effective as Imatinib without suppression of bone marrow. Icaritin could up-regulate phospho-JNK or phospho-C-Jun and down-regulate phospho-ERK, phospho-P-38, Jak-2, phospho-Stat3 and phospho-Akt expression with dose- or time-dependent manner. Icaritin had no influence both on c-Abl and phospho-c-Abl protein expression and mRNA levels of Bcr/Abl. CONCLUSION: Icaritin from Chinese herb medicine may be a potential anti-CML agent with low adverse effect. The mechanism of anti-leukemia for Icaritin is involved in the regulation of Bcr/Abl downstream signaling. Icaritin may be useful for an alternative therapeutic choice of Imatinib-resistant forms of CML.

[Synthesis of 5-aryl-4-cyano-1H-1, 2, 3-triazoles and biological evaluation of their inhibitory action on tyrosine kinase].

5-Aryl-4-cyano-1H-1, 2, 3-triazoles bearing a variety of substituting groups on 5-phenyl were synthesized. Their structures were established by MS, IR and 1H NMR spectra. The crystal structures of compounds 3f and 3m were determined by X-ray diffraction analysis. The active H of the triazole was on 1-N from the crystal structures. The compounds, designed as HER2 tyrosine kinase inhibitors, were screened for bioactivity of growth-inhibition of breast cancer MDA-MB-453 cells. The lowest IC50 value of inhibiting HER2 tyrosine kinase phosphorylation in breast cancer cells is 6.6 micromol x L(-1). The inhibiting-growth of breast cancer cells was enhanced from electron-drawing groups joining 5-phenyl on the triazole.

Aspirin induces lytic cytotoxicity in Epstein-Barr virus-positive cells.

Epstein-Barr virus (EBV) infection in tumor cells is generally restricted to the latent forms of viral infection. Switching the latent form of viral infection into the lytic form may induce tumor cell death. High levels of nuclear factor (NF)-kappaB can inhibit EBV lytic replication, and aspirin has the ability to inhibit NF-kappaB activity. The aims of the current study were to determine the effects of aspirin on inducing EBV lytic infection, and thus to reveal the possibility of targeting EBV-positive cancer cells by aspirin. Our results showed that aspirin depleted NF-kappaB (p65) in the nucleus and reactivated EBV into lytic replication. Cells exhibited decreased viability in a dose- and time-dependent manner when incubated with aspirin. When ganciclovir was used in combination with aspirin to treat EBV-positive B95.8 cells and Raji cells, the cytotoxic effect of aspirin was amplified. We demonstrated that aspirin reduced the viability of EBV-positive B lymphocytes due to its ability to induce EBV lytic replication.

NF-kappaB inhibitors induce lytic cytotoxicity in Epstein-Barr virus-positive nasopharyngeal carcinoma cells.

Epstein-Barr virus (EBV) infection in tumor cells is generally restricted to the latent forms of viral infection. Switching the latent form of viral infection into the lytic form may induce tumor cell death. An important nuclear factor, nuclear factor (NF)-kappaB, is thought to play an essential role in EBV lytic infection; high levels of NF-kappaB can inhibit EBV lytic replication. In this study, we tested the effect of inducing EBV lytic replication using two NF-kappaB inhibitors: Bay11-7082 and Z-LLF-CHO, to reveal the possibility of targeting EBV-positive cancer therapy with these two NF-kappaB inhibitors. Our results showed that Bay11-7082 and Z-LLF-CHO reactivated EBV in a dose-dependent manner, thus resulting in EBV-positive 5-8F cell death. In contrast, there was no significant effect on EBV-negative HNE3 cells. When ganciclovir was used in combination with either Bay11-7082 or Z-LLF-CHO to treat 5-8F cells, the cytotoxic effect of the NF-kappaB inhibitor was amplified. The finding indicates that inhibiting the NF-kappaB activity of EBV-positive cells can induce lytic replication of EBV and cause lytic cytotoxicity against these cells.

Grifolin, a potential antitumor natural product from the mushroom Albatrellus confluens, inhibits tumor cell growth by inducing apoptosis in vitro.

Grifolin is a natural biologically active substance isolated from the fresh fruiting bodies of the mushroom Albatrellus confluens. Here, for the first time, we describe a novel activity of grifolin, namely its ability to inhibit the growth of tumor cells by the induction of apoptosis. Grifolin strongly inhibited the growth of tumor cell lines: CNE1, HeLa, MCF7, SW480, K562, Raji and B95-8. Analysis of acridine orange (AO)/ethidium bromide (EB) staining and flow cytometry showed that grifolin possessed apoptosis induction activity to CNE1, HeLa, MCF7 and SW480. Furthermore, the cytochrome c release from mitochondria was detected by confocal microscopy in CNE1 cells after a 12h treatment with grifolin. The increase of caspase-8, 9, 3 activities revealed that caspase was a key mediator of the apoptotic pathway induced by grifolin, and the underexpression of Bcl-2 and up-regulation of Bax resulted in the increase of Bax: Bcl-2 ratio, suggesting that Bcl-2 family involved in the control of apoptosis. Owing to the combination of the significant antitumor activity by inducing apoptosis and natural abundance of the compound, grifolin holds the promise of being an interesting antitumor agent that deserves further laboratory and in vivo exploration.