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.

[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.

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.