Analysis of genetic characteristics and reproductive risks of balanced complex chromosome rearrangement carriers in China.

To examine the type, characteristics and meiotic behavior of balanced complex chromosome rearrangements (CCRs) and their relationship with reproductive abnormalities in Chinese people, karyotype analyses were performed in 1063 couples with reproductive abnormalities using G-banding technology. Additional data were retrieved from a Chinese database and analyzed statistically with the karyotype and clinic data of CCRs. Two CCR carriers were found among the 1063 couples, and in all a total of 124 CCR carriers with the complete information were identified in the karyotype analysis and the database search. Our results showed that simple 3-way or 4-way translocations were the most common types, present in 64/124 (51.6%) of CCRs. Double two-way translocations accounted for 26.6% and exceptional CCRs accounted for 21.6% of total cases. General risk of 77.6% for spontaneous abortions and 9.7% for an abnormal child were calculated based on 339 pregnancies of 124 carriers. Pregnancy consequences could be significantly associated with the type of CCRs. Abnormal pregnancy was frequently associated with CCRs on chromosome 8, while dyszoospermia was frequently associated with CCRs on chromosome 1 among the males. The most frequent mode of segregation was 3:3 adjacent-1 (8/12) in 12 abnormal karyotypes. Short chromosomes (groups D-G) were involved in 46.2% of CCRs showing 3:2, 4:2 and 5:3 segregation ratios. In conclusion, carriers of balanced CCRs have a high risk of an abortion and/or a chromosomally unbalanced child. The incidence of spermatogenic defect in male CCR carriers is high, and male infertility is associated with CCRs. Hence, identifying the types of CCRs, chromosomes involved, translocated segments of chromosomes, etc. will provide crucial information for prenatal diagnosis and genetic counseling for carriers of balanced CCRs.

Betaine Effects on Morphology, Proliferation, and p53-induced Apoptosis of HeLa Cervical Carcinoma Cells in Vitro.

OBJECTIVES: To investigate the effects of betaine on HeLa cell growth and apoptosis and molecular mechanisms. MATERIALS AND METHODS: Concentrations of 0.1, 1.0, 5.0, 20.0, 100.0 mg/ml of betaine were used to evaluate the anticancer efficacy for HeLa cells respectively, and MCF-10A was also detected as a normal diploid cell control. RESULTS: We found that proliferation of HeLa cells was inhibited significantly upon exposure to increasing betaine levels with the MTT test (p<0.05). The percentage of S phase cells in the low dose groups (< 5mg/ml) were distinctly higher than in high dose groups, and the rates of Sub-G1 phase were the opposite (p<0.01); A high concentration of betaine (>5.0mg/ml) significantly promoted the apoptosis of HeLa cells (p<0.01). SOD activities of the low dose groups were slightly higher than the control group (p<0.05) and there were obvious synchronicity and correlation among the expression of promoting apoptosis genes Bax, P53, Caspase 3 and apoptosis suppression gene Bcl-2. In response to an apoptosis-inducing stimulus, p53 and cyclin D1 could be activated with blockage of the cell cycle at G1/S or S/G2 checkpoints. CONCLUSIONS: Our data showed that betaine could promote HeLa cells proliferation in vitro at low concentrations.In contrast, high concentrations could significantly inhibit cell growth and migration, and induce apoptosis of HeLa cells through caspase 3 signaling and further promoted necrosis. This might imply that betaine exhibits tumoricidal effects and acts as a biological response modifier in cancer treatment by inducing apoptosis and cell cycle arrest in a dose and time-dependent manner.

Prophylactic antiviral therapy in allogeneic hematopoietic stem cell transplantation in hepatitis B virus patients.

AIM: To investigate the timing, safety and efficacy of prophylactic antiviral therapy in patients with hepatitis B virus (HBV) infection undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: This prospective study recruited a total of 57 patients diagnosed with malignant hematological diseases and HBV infection at the First Affiliated Hospital of Sun Yat-sen University between 2006 and 2013. The patients were classified as hepatitis B surface antigen (HBsAg)-positive or HBsAg-negative/ antiHBc-positive. Patients were treated with chemotherapy followed by antiviral therapy with nucleoside analogues. Patients underwent allo-HSCT when serum HBV DNA was < 10(3) IU/mL. Following allo-HSCT, antiviral therapy was continued for 1 year after the discontinuation of immunosuppressive therapy. A total of 105 patients who underwent allo-HSCT and had no HBV infection were recruited as controls. The three groups were compared for incidence of graft-vs-host disease (GVHD), drug-induced liver injury, hepatic veno-occlusive disease, death and survival time. RESULTS: A total of 29 of the 41 subjects with chronic GVHD exhibited extensive involvement and 12 exhibited focal involvement. Ten of the 13 subjects with chronic GVHD in the HBsAg(-)/hepatitis B core antibody(+) group exhibited extensive involvement and 3 exhibited focal involvement. Five of the 10 subjects with chronic GVHD in the HBsAg(+) group exhibited extensive involvement and 5 exhibited focal involvement. The non HBV-infected group did not differ significantly from the HBsAg-negative/antiHBc-positive and the HBsAg-positive groups which were treated with nucleoside analogues in the incidence of graft-vs-host disease (acute GVHD; 37.1%, 46.9% and 40%, respectively; P = 0.614; chronic GVHD; 39%, 40.6% and 40%, respectively; P = 0.98), drug-induced liver injury (25.7%, 18.7% and 28%, respectively; P = 0.7), death (37.1%, 40.6% and 52%, respectively; P = 0.4) and survival times (P = 0.516). One patient developed HBV reactivation (HBsAg-positivity) due to early discontinuation of antiviral therapy. CONCLUSION: Suppression of HBV DNA to < 10(3) IU/mL before transplantation, continued antiviral therapy and close monitoring of immune markers and HBV DNA after transplantation may assure the safety of allo-HSCT.

In vitro study of nucleostemin as a potential therapeutic target in human breast carcinoma SKBR-3 cells.

Although nucleolar protein nucleostemin (NS) is essential for cell proliferation and early embryogenesis and expression has been observed in some types of human cancer and stem cells, the molecular mechanisms involved in mediation of cell proliferation and cell cycling remains largely elusive. The aim of the present study was to evaluate NS as a potential target for gene therapy of human breast carcinoma by investigating NS gene expression and its effects on SKBR-3 cell proliferation and apoptosis. NS mRNA and protein were both found to be highly expressed in all detected cancer cell lines. The apoptotic rate of the pcDNA3.1-NS-Silencer group (12.1-15.4 ± 3.8%) was significantly higher than those of pcDNA3.1-NS (7.2-12.0 ± 1.7%) and non-transfection groups (4.1-6.5 ± 1.8%, P<0.01). MTT assays showed the knockdown of NS expression reduced the proliferation rate of SKBR-3 cells significantly. Matrigel invasion and wound healing assays indicated that the number of invading cells was significantly decreased in the pcDNA3.1-NS-siRNA group (P<0.01), but there were no significant difference between non-transfected and over-expression groups (P>0.05). Moreover, RNAi-mediated NS down- regulation induced SKBR-3 cell G1 phase arrest, inhibited cell proliferation, and promoted p53 pathway-mediated cell apoptosis in SKBR-3 cells. NS might thus be an important regulator in the G2/M check point of cell cycle, blocking SKBR-3 cell progression through the G1/S phase. On the whole, these results suggest NS might be a tumor suppressor and important therapeutic target in human cancers.

[Folate gene polymorphism and the risk of Down syndrome pregnancies in young Chinese women].

To explore the relationship between genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), reduced folate carrier1 (RFC-1), methionine synthase (MTR) involved in folate metabolism and the risk of offsprings of young Chinese women with Down syndrome (DS) through a case-control study, the polymorphisms of MTHFR 677C>T, MTRR 66A>G, RFC-1 80G>A, and MTR 2756A>G in 60 mothers of children with DS and 68 control mothers were investigated by PCR-RFLP. Significant differences in alle-lic frequencies were present between the cases and controls for MTHFR (Plt;0.05), but not in allelic frequencies for MTRR, RFC-1, and MTR. Homozygous MTHFR 677C>T polymorphism was more prevalent among the mothers of children with DS than among the control mothers, with an odds ratio of 3.51 (OR=3.51, 95% CI=1.30~9.46, Plt;0.05). No significant association was observed in the combined heterozygotes. In addition, the homozygous MTRR 66A>G polymorphism was independently associated with a 3.16-fold increase in estimated risk (OR=3.16, 95% CI=1.20~8.35, Plt;0.05). The increased risk of DS for homozygous RFC-1 80G>A was not associated with MTR 2756A>G. Positive interactions were found for the following genotype-pairs: MTHFR(CT+TT)/MTRR GG, MTHFR (CT+TT)/RFC-1 AA, MTHFR CC/MTR(AG+GG), MTHFR (CT+TT)/MTR AA, MTRR GG/MTR AA, and RFC-1 AA/MTRAA. In conclusion, MTHFR 677C>T and MTRR 66A>G polymorphisms are two independent risk factors for DS pregnancies in young women, but RFC-1 80G>A and MTR 2756A>G polymorphism are not independent risk factor. A role for combined genotypes in the risk of DS pregnancies cannot be excluded.