CDC6, a key replication licensing factor, is overexpressed and confers poor prognosis in diffuse large B-cell lymphoma.

BACKGROUND: Cell division cycle 6 (CDC6) is a key licensing factor in the assembly of pre-replicative complexes at origins of replication. The role of CDC6 in the pathogenesis of in diffuse larger B-cell lymphoma (DLBCL) remains unknown. We aim to investigate the effects of CDC6 on the proliferation, apoptosis and cell cycle regulation in DLBCL cells, delineate its underlying mechanism, and to correlate CDC6 expression with clinical characteristics and prognosis of patients with DLBCL. METHODS: Initial bioinformatic analysis was performed to screen the potential role of CDC6 in DLBCL. Lentiviral constructs harboring CDC6 or shCDC6 was transfected to overexpress or knockdown CDC6 in SUDHL4 and OCI-LY7 cells. The cell proliferation was evaluated by CCK-8 assay, cell apoptosis was detected by Annexin-V APC/7-AAD double staining, and cell cycle was measured by flow cytometry. Real time quantitative PCR and western blot was used to characterize CDC6 expression and its downstream signaling pathways. The clinical data of DLBCL patients were retrospectively reviewed, the CDC6 expression in DLBCL or lymph node reactive hyperplasia tissues was evaluated by immunohistochemistry. RESULTS: In silico data suggest that CDC6 overexpression is associated with inferior prognosis of DLBCL. We found that CDC6 overexpression increased SUDHL4 or OCI-LY7 cell proliferation, while knockdown of CDC6 inhibited cell proliferation in a time-dependent manner. Upon overexpression, CDC6 reduced cells in G1 phase and did not affect cell apoptosis; CDC6 knockdown led to significant cell cycle arrest in G1 phase and increase in cell apoptosis. Western blot showed that CDC6 inhibited the expression of INK4, E-Cadherin and ATR, accompanied by increased Bcl-2 and deceased Bax expression. The CDC6 protein was overexpressed DLBCL compared with lymph node reactive hyperplasia, and CDC6 overexpression was associated with non-GCB subtype, and conferred poor PFS and OS in patients with DLBCL. CONCLUSION: CDC6 promotes cell proliferation and survival of DLBCL cells through regulation of G1/S cell cycle checkpoint and apoptosis. CDC6 is overexpressed and serves as a novel prognostic marker in DLBCL.

Clinical and Genetic Analysis of a Family With Sitosterolemia Caused by a Novel ATP-Binding Cassette Subfamily G Member 5 Compound Heterozygous Mutation.

Sitosterolemia (OMIM ##210250), also known as phytosterolemia, is a rare autosomal recessive disorder caused by mutations in the ATP-binding cassette subfamily G member 5 (ABCG5) or member 8 (ABCG8) genes. This leads to abnormal functions of the transporter sterolin-1 protein encoded by ABCG5 and sterolin-2 protein encoded by ABCG8, respectively, which can hinder the formation of stable ABCG5/G8 heterodimers, decreasing its ability to transport sterols. As a result, phytosterols in tissue or plasma are significantly increased, leading to early onset atherosclerosis-related diseases and xanthelasma of tendons and skin. In this study, whole exome sequencing was performed on a Chinese Han proband with sitosterolemia to capture the target gene and screen for suspected pathogenic mutations. Sanger sequencing of the family members was performed to verify the relationship between family genetics and phenotypes. The structural and functional changes in the transporter sterolin-1 protein after the responsible mutation were predicted using bioinformatics analysis. A novel compound heterozygous mutation in the ABCG5 gene (NM_022436) was identified in a proband with sitosterolemia, one of which was inherited from the father: c.296T >G (p.M99R), and one from the mother: c.-76 C >T. SIFT, Polyphen2, and Mutation Taster software predicted that p.M99R may be the responsible variant and a novel variant. RNAFold software predicts that c.-76 C >T may affect the transcriptional information or the binding of RNA binding proteins by regulating the structure of RNA, and ultimately affect gene transcription or RNA stability and translation. Swiss model software predicts that the amino acid sequence around p.M99R is highly conserved, and p.M99R leads to instability of the tertiary structure of the ABCG5/ABCG8 heterodimer. GPS 5.0 predicted that M99R affects the phosphorylation of nearby amino acid sequences, and DUET and VarSite software predicted that M99R affects the stability of sterolin-1 and cause disease. The p.M99R and c.-76 C >T mutations led to the formation of unstable heterodimers, which disturbed sterol absorption and excretion in vivo. The compound heterozygous variants c.296 T >G (p.m99r) and C.-76 C >T on exon 3 of ABCG5 in this family may be the molecular genetic basis of sitosterolemia.

Development and Characterization of a Neutralizing Anti-idiotype Antibody Against Mirvetuximab for Analysis of Clinical Samples.

Antibody-drug-conjugates (ADCs) are an emerging class of biological therapeutics. Mirvetuximab soravtansine is a novel folate receptor alpha (FRα)-targeting ADC which represents a potential new treatment for patients with ovarian and other FRα-positive cancers. Since patient immune responses to biological therapeutics may negatively affect drug efficacy and patient safety, regulatory authorities require rigorous monitoring of patient samples. Taking advantage of the immune system's ability to generate highly specific antibodies, the field has turned to anti-idiotype antibodies as powerful tools for the development of sensitive and specific bioassays. Here, we report the generation and characterization of a highly specific neutralizing anti-idiotype antibody directed against M9346A, the antibody moiety of mirvetuximab soravtansine. The anti-idiotype antibody recognizes M9346A with double-digit picomolar affinity, competes with folate receptor antigen for binding to M9346A, and can be used to develop both anti-drug-antibody and neutralizing antibody assays.

[Therapeutic Efficacy of VICP+L-ASP/TKI on Adult Patients with B-ALL].

OBJECTIVE: To evaluate the therapeutic efficacy of VICP+L-ASP/TKI on adult patients with B-ALL and to explore the influence factors. METHODS: Forty-one adult B-ALL patients treated with VICP+L-ASP/TKI from August 2008 to June 2014 were following-up. The complete remission(CR) rate, toxicity, overall survival(OS) and event free survival(EFS) after induction treatment were analyzed, the therapeutic outcome of patients between different risk stratification subgroups was compared, the influence of standardized consolidatory and maintaining treatment as well as allogeneic hematopoietic stem cell transplantation(allo-HSCT) on survival time was analyzed. RESULTS: The early death not occurred in 41 patients with B-ALL including 37 cases with CR; the CR rate of 1 course treatment was 90.2%. The follow-up time lasted to March 17, 2015, the median follow-up time was 25(9-79) months; the 1 year OS rate was 75.3%, the EFS rate was 58.3%. Analysis of risk factors showed that the initial WBC count over 30×109/L, LDH over 250 U/L and minimal residual disease(MRD) over 10-4 after treatment were poor prognostic factors. After remission, the standardized consolidatory treatment or allo-HSCT according to the "2012 China adult ALL diagnosis and treatment expert consensus" could improve long-term survival, 3 years OS rate was 73.8% and 61.5% respectively, 3 years EFS were 63.5% and 65.7% respectively. The main toxic and side effects were hematologic reactions, the hematologic adverse reaction of IV grade was observed in 97.6%(40/41) during induction treatment. CONCLUSION: Induction chemotherapy based on VICP+L-ASP/TKI and standardized consolidatory after remission according to the "2012 China adult acute lymphoblastic leukemia diagnosis and treatment expert consensus" can improve the therapeutic efficacy. The allo-HSCT should be actively performed for B-ALL paients with high risk(elevated initial WBC count and LDH level); at some time, the regularly monitoring MRD and adjusting therapeutic protocol according to monitoring result can promote the prognosis of adult B-ALL patients.

Magnetic nanoparticle of Fe3O4 and 5-bromotetrandrin interact synergistically to induce apoptosis by daunorubicin in leukemia cells.

Apoptosis is a common pathway that finally mediated the killing functions of anticancer drugs, which is an important cause of multidrug resistance (MDR). The aim of this study was to investigate the potential benefit of combination therapy with magnetic nanoparticle of Fe(3)O(4) (MNP(Fe(3)O(4))) and 5-bromotetrandrin (BrTet). Analysis of the apoptosis percentage showed that combination of daunorubicin (DNR) with either MNP(Fe(3)O(4)) or BrTet exerted a potent cytotoxic effect on K562/A02 cells, while MNP(Fe(3)O(4)) and BrTet cotreatment can synergistically enhance DNR-induced apoptosis. Importantly, we confirmed that the distinct synergism effect of that composite on reverse multidrug resistance may owe to the regulation of various proliferative and antiapoptotic gene products, including P53 and caspase-3. Thus our in vitro data strongly suggests a potential clinical application of MNP(Fe(3)O(4)) and BrTet combination on CML.

Effects of magnetic nanoparticle of fe(3)o(4) and 5-bromotetrandrine on apoptosis of K562/A02 leukemic cells induced by daunorubicin.

The aim of this study was to investigate the potential benefit of combination therapy with magnetic nanoparticle of Fe(3)O(4) and 5-Bromotetrandrine (5-BrTet) on chronic leukemia. The apoptosis was detected by flow cytometry (FCM), Wright staining and light microscope; the expressions of BAX and BCL-2 were measured by Western blot. The results showed that combination of daunorubicin (DNR) with either MNP (Fe(3)O(4)) or 5-BrTet exerted a potent cytotoxic effect on K562/A02 cells, while MNP (Fe(3)O(4)) and 5-BrTet co-treatment could synergistically enhance DNR-induced apoptosis. After treated with this regimen, the typical apoptotic morphological features were found in K562/A02 cells; the expression level of BCL-2 decreased and BAX increased markedly. It is concluded that MNP (Fe(3)O(4)) or 5-BrTet with DNR can induce apoptosis in K562/A02 cells, and they show distinct synergism when used together. The down-regulation of BCL-2 and the up-regulation of BAX may play important roles.