Context Matters: Distinct Disease Outcomes as a Result of Crebbp Hemizygosity in Different Mouse Bone Marrow Compartments

Perturbations in CREB binding protein (CREBBP) are associated with hematopoietic malignancies, including myelodysplastic syndrome (MDS). Mice hemizygous for Crebbp develop myelodysplasia with proliferative features, reminiscent of human MDS/myeloproliferative neoplasm-unclassifiable (MDS/MPN-U), and a proportion goes on to develop acute myeloid leukemia (AML). We have also shown that the Crebbp+/- non-hematopoietic bone marrow microenvironment induces excessive myeloproliferation of wild-type cells. We now report that transplantation of unfractionated Crebbp+/- bone marrow into wild-type recipients resulted in either early-onset AML or late-onset MDS and MDS/MPN-U. In contrast, purified Lin-Sca-1+c-Kit++ cells primarily gave rise to MDS with occasional transformation to AML. Furthermore, Crebbp+/- common myeloid progenitors and granulocyte/macrophage progenitors could trigger skewed myelopoiesis, myelodysplasia and late-onset AML. Surprisingly, the phenotypically abnormal cells were all of wild-type origin. MDS, MPN and AML can thus all be transferred from Crebbp+/- BM to wild-type hosts but fractionated bone marrow does not recapitulate the full disease spectrum of whole bone marrow, indicating that not only mutational status but also cellular context contribute to disease outcome. This has important consequences for structuring and interpreting future investigations into the underlying mechanisms of myeloid malignancies as well as for their treatment.

Correlation between polymorphisms in the glucocorticoid receptor gene NR3C1 and susceptibility to asthma in a Chinese population from the Henan Province

The aim of this study was to investigate the association between four single nucleotide polymorphisms in NR3C1 (Tth111I, BclI, ER22/23EK, and N363S), which encode the glucocorticoid receptor, and asthma susceptibility in patients from the Henan Province of China. Three hundred and twenty-eight patients with asthma and 60 healthy volunteers were recruited to this study. The target SNPs were genotyped by polymerase chain reaction (PCR)-high resolution melting and PCR-restriction fragment length polymorphism. The frequencies of the AA (8.84%) and GG (30.79%) genotypes of Tth111I were higher, and that of the AG genotype was lower (60.37%), in the asthma patients compared to that seen in healthy controls (5.00, 26.67, and 68.33%, respectively). On the other hand, asthma patients showed higher frequencies of the AA genotype (78.05%) of N363S, and lower frequencies of the AG and GG genotypes (15.55 and 6.40%), compared to healthy volunteers (71.67, 18.33, and 10.00%, respectively). Neither of these differences were found to be statistically significant. Moreover, we observed no significant differences in the genotype or allele frequencies of the BclI and ER22/23EK SNPs between the patient and control groups. In conclusion, SNPs in NR3C1 were not significantly associated with asthma in patients from the Henan Province. Patients showed higher frequencies of the AA and GG genotypes of Tth111I and the AA genotype of the N363S SNP compared to healthy volunteers, although these differences were not significant.

Multicentre study to evaluate the clinical effects of laparoscopic uterine artery occlusion in combination with myomectomy to treat symptomatic uterine leiomyomas

OBJECTIVE

Uterine artery occlusion is often used to treat symptomatic uterine myomas, as this is a minimally invasive approach. However, alternative methods for uterus-sparing therapy are in development. This study aimed to compare the clinical effects of laparoscopic uterine artery occlusion (LUAO) in combination with laparoscopic myomectomy (LM) with LM alone for the management of symptomatic uterine leiomyomas.

STUDY DESIGN

This multicentre study was a retrospective controlled investigation. In total, 618 patients with symptomatic uterine myomas from six hospitals in Eastern China underwent LUAO+LM or LM alone between June 2011 and December 2012. Operative time, blood loss, transfusion, highest temperature, postoperative hospital stay, complications and follow-up results were compared between the two groups.

RESULTS

Complete clinical data were available for 504 patients. Among these, 324 patients underwent LUAO+LM and 180 patients underwent LM alone. Mean±standard deviation blood loss, transfusion, highest peri-operative temperature and duration of hospital stay were significantly lower in the LUAO+LM group compared with the LM group (83.61±53.70ml vs 109±58.43ml, 1.85% vs 6.11%, 37.6±0.40°C vs 37.9±0.45°C and 5.11±0.62 days vs 6.10±0.83 days, respectively). The mean duration of follow-up was 38.97±5.82 months in the LUAO+LM group and 37.30±2.25 months in the LM group (p>0.05). The relief of abnormal uterine bleeding, reduction of uterine volume and recurrence of myomas were more remarkable in the LUAO+LM group than the LM group (97.22% vs 83.75%, 62.42% vs 51.83% and 3.47% vs 10.63%, respectively).

CONCLUSIONS

LUAO in combination with LM was associated with higher surgical quality, greater relief of abnormal symptoms and less recurrence of myomas compared with LM alone. LUAO in combination with LM is recommended for women with symptomatic uterine myomas who wish to preserve their uterus.

The effects of ginsenoside Rg1 on chronic stress induced depression-like behaviors, BDNF expression and the phosphorylation of PKA and CREB in rats

Depression is a common neuropsychiatric disorder which has been associated with a wide range of structural and functional changes within specific brain regions. Ginsenoside Rg1 has been shown to exert a number of neuroprotective effects as demonstrated in various in vivo and in vitro studies. However, little information is available regarding the site and mechanisms of ginsenoside Rg1 in promoting antidepressant effects. The present study aimed to investigate the neuroprotective and ameliorating effects of ginsenoside Rg1 on depression-like behavior as induced by chronic unpredictable mild stress (CUMS). The results showed that CUMS was effective in producing depression-like behaviors in rats as indicated by decreased responses in sucrose preference and forced swim tests which were associated with ultrastructural changes in neurons within the amygdala. Moreover, levels of PKA and CREB phosphorylation and the expression of brain-derived neurotrophic factor (BDNF) were decreased in the amygdala of CUMS rats. Remarkably, chronic ginsenoside Rg1 (40 mg/kg, i.p., 5 weeks) treatment significantly ameliorated these behavioral and biochemical alterations associated with CUMS-induced depression. Taken together, the results of the present study demonstrate that ginsenoside Rg1 exhibits antidepressant-like effects against CUMS-induced depression. This amelioration of depression-like behaviors by ginsenoside Rg1 appears to be mediated, at least in part, by a CREB-regulated increase of BDNF expression in the amygdala of rats. Therefore, these findings reveal the therapeutic potential of ginsenoside Rg1 for use in clinical trials in the treatment of depression.

Mutational analysis of HOXA10 gene in Chinese patients with cryptorchidism

Cryptorchidism is one of the most common congenital anomalies and affects 2-4% of full-term new born boys. Its aetiology is poorly understood at present. HOXA10 plays a pivotal role in regulation of testicular descent. Male mice mutant for Hoxa10 exhibit unilateral or bilateral cryptorchidism as a result of impaired development of the gubernaculums. In this study, we performed mutation analysis of HOXA10 gene in a cohort of 98 cryptorchid patients. And we found a mutation (N27K) in a boy with unilateral cryptorchidism. The mutation was not detected in 106 healthy controls. Both in silico analyses and functional studies showed that the mutation affected the function of HOXA10. The results demonstrated that mutation in HOXA10 gene contributes to the pathogenesis of cryptorchidism, but may not be a common cause.

ARHGAP10, downregulated in ovarian cancer, suppresses tumorigenicity of ovarian cancer cells

Rho GTPase-activating proteins (RhoGAPs) are implicated in the development and progression of ovarian cancer. ARHGAP10 is a member of RhoGAP proteins and inactivates Cdc42 by converting GTP-bound form to GDP-bound form. Here, we aimed to evaluate ARHGAP10 expression profile and functions in ovarian cancer. The decreased expression of ARHGAP10 was found in 77.3% (58/75) of ovarian cancer tissues, compared with their non-tumorous counterparts. Furthermore, overall survival in ovarian cancer patients with higher expression of ARHGAP10 was longer than those with lower expression. Ectopic expression of ARHGAP10 in two ovarian cancer cell lines with lower expression of ARHGAP10 (A2780 and HO-8910) dramatically suppressed cell proliferation in vitro. In nude mice, its stable overexpression significantly inhibited the tumorigenicity of A2780 cells. We further demonstrated that overexpression of ARHGAP10 significantly inhibited cell adhesion, migration and invasion, resulted in cell arrest in G1 phase of cell cycle and a significant increase of apoptosis. Moreover, ARHGAP10 interacted with Cdc42 and overexpression of ARHGAP10 inhibited the activity of Cdc42 in A2780 cells. Gene set enrichment analysis on The Cancer Genome Atlas dataset showed that KEGG cell cycle, replication and base excision repair (BER) pathways were correlatively with the ARHGAP10 expression, which was further confirmed in ovarian cancer cells by western blotting. Hence, ARHGAP10 may serve as a tumor suppressor through inactivating Cdc42, as well as inhibiting cell cycle, replication and BER pathways. Our data suggest an important role of ARHGAP10 in the molecular etiology of cancer and implicate the potential application of ARHGAP10 in cancer therapy.

Tumor-suppressive function of long noncoding RNA MALAT1 in glioma cells by downregulation of MMP2 and inactivation of ERK/MAPK signaling

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a type of long noncoding RNA. It is associated with metastasis and is a favorable prognostic factor for lung cancer. Recent studies have shown that MALAT1 plays an important role in other malignancies. But, little is known about the role of MALAT1 in glioma. In this study, quantitative reverse transcription PCR (qRT-PCR) was used to demonstrate that the expression of MALAT1 was lower than that in normal brain tissues. Stable RNA interference-mediated knockdown of MALAT1 in human glioma cell lines (U87 and U251) significantly promoted the invasion and proliferation of the glioma cells by in vitro assays. Conversely, overexpression of MALAT1 caused significant reduction in cell proliferation and invasion in vitro, and tumorigenicity in both subcutaneous and intracranial human glioma xenograft models. Furthermore, MALAT1-mediated tumor suppression in glioma cells may be via reduction of extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling activity and expression of matrix metalloproteinase 2 (MMP2). In conclusion, overall data demonstrated the tumor-suppressive role of MALAT1 in glioma by attenuating ERK/MAPK-mediated growth and MMP2-mediated invasiveness.

No influence of CYP2D6*10 genotype and phenotype on the pharmacokinetics of nebivolol in healthy Chinese subjects

WHAT IS KNOWN AND OBJECTIVE

Nebivolol, a clinically important antihypertensive drug, mainly metabolized by cytochrome P450 (CYP) 2D6, shows wide interindividual variability in pharmacokinetics. The CYP2D6*10 allele (100C>T; rs1065852), present at a high frequency in the Chinese population, is associated with alteration in the pharmacokinetics of many drugs, but its effect on the pharmacokinetics of nebivolol is unknown. The aim of our study was to investigate whether the CYP2D6*10 genotype and phenotype are associated with changes in the pharmacokinetics of nebivolol in Chinese subjects.

METHODS

Twenty-four healthy subjects were divided into three groups according to CYP2D6*1/*1 (n = 7), CYP2D6*1/*10 (n = 5) and CYP2D6*10/*10 (n = 12) genotypes. The *1/*1 homozygotes and *1/*10 heterozygotes were C allele carriers. All subjects received oral single dose of nebivolol and dextromethorphan. Blood and urine samples were gathered at various times.

RESULTS

There were no statistically significant differences in the pharmacokinetics of nebivolol between the three CYP2D6*10 genotypes, and no gene-dose effect was seen. The pharmacokinetic parameters of CYP2D6*10/*10 subjects were also similar to those of CYP2D6*1 carriers. A weak relationship between CYP2D6 phenotype and nebivolol clearance was found.

WHAT IS NEW AND CONCLUSION

The CYP2D6*10 genotype and phenotype were not associated with significant alterations in the pharmacokinetics of nebivolol. CYP2D6*10 alone does not account for the large interindividual differences observed in the disposition of nebivolol among Chinese healthy subjects.

Effect of oleic acid supplementation on prostaglandin production in maternal endometrial and fetal allantochorion cells isolated from late gestation ewes

INTRODUCTION

Elevated circulating non-esterified fatty acids including oleic acid (OA) are associated with many pregnancy related complications. Prostaglandins (PGs) play crucial roles during parturition. We investigated the effect of OA supplementation on PG production using an in vitro model of ovine placenta.

METHODS

Maternal endometrium (ME) and fetal allantochorion (FC) were collected in late pregnancy (day 135). Confluent cells were cultured in serum-free medium supplemented with 0, 20 or 100 μM OA and challenged with control medium, oxytocin (OT, 250 nM), lipopolysaccharide (LPS, 0.1 μg/ml) or dexamethasone (DEX, 5 μM). Spent medium was harvested at 2 and 24 h after challenge for quantifying PGs.

RESULTS

In ME cells OA increased PGE2 production moderately but attenuated PGF2α production leading to a doubling of the PGE2:PGF2α ratio (E:F) (P < 0.01). Without OA, both OT and LPS stimulated PG production for about 3-fold (P < 0.01) without changing the E:F ratio. In the ME cells challenged with OT, OA decreased both PGE2 and PGF2α production by up to 70% (P < 0.01) whereas in LPS treated cells OA increased the E:F ratio. In FC cells PGE2 production at 2 h was stimulated by 100 μM OA (P < 0.05). In these cells LPS caused a 3-fold increase in PGE2 (P < 0.01), an effect which was completely inhibited by DEX.

DISCUSSION

OA supplementation favours basal PGE2 production in both ME and FC. In ME OA increased E:F ratios and antagonized the stimulatory effect of OT on PG production. This suggests that raised circulating OA may affect both the initiation and progression of parturition.

Caesarean Sections in Beijing, China - Results from a Descriptive Study

OBJECTIVE

Caesarean section rates are increasing dramatically in China. The predominant contributor to the increase in China was the unnecessary Caesarean section. The objective of this study was to estimate the excess economic burden caused by unnecessary Caesarean sections vs. vaginal delivery for Beijing and all China.

METHODS

The 33 476 obstetric medical case files from randomly selected 17 hospitals of Beijing in 2011 were taken for our descriptive approach. Based on the individual medical files and on a definition of what necessary and unnecessary Caesarean sections are, we sampled also the data for costs and length of stay for comparisons with vaginal deliveries. The Mann-Whitney U test and Pearson chi-square test statistics were used to test for significant difference in the analysis.

RESULTS

The Caesarean section rate was 58.5% among all deliveries and that rate of unnecessary Caesarean sections was 71.5% among all the Caesarean sections but 41.8% among all deliveries in Beijing. The hospitalisation expenses of unnecessary Caesarean sections were 472 US$ higher than that of a vaginal delivery on average. The total excess economic burden caused by unnecessary Caesarean sections can be estimated to 38.97 million US$ for Beijing and to 3.29 billion US$ all over China in 2011. This is equivalent to the annual health expenditure of over 139 575 residents in Beijing and of 11 783 120 residents in China, respectively.

CONCLUSION

Socio-economic factors are possible reasons for the increase of unnecessary Caesarean section in China and more analytical attention should be paid to that problem in order to propose fitting practical reactions.

Abstract B27: Novel insights into the pathogenesis of myelodysplastic syndrome using Crebbp+/- mice

Myelodysplastic syndrome (MDS) is a hematopoietic stem cell (HSC) disease, characterized by ineffective hematopoiesis, dysplasia in one or more hematopoietic lineages and increased risk of leukemic transformation. Although predominantly found in the elderly, MDS also occurs in children, particularly in those with hereditary defects in genes important for DNA repair and in those after treatment with DNA damaging alkylating agents and topoisomerase II inhibitors. Childhood MDS often progresses rapidly to acute myeloid leukemia (AML), at which point there are no good therapeutic options and thus the prognosis of this disease is extremely poor. Acquired and inherited perturbations in CREB binding protein (Crebbp) have been associated with MDS and AML in children. Mice, engineered to carry only one allele of the Crebbp gene are defective in DNA repair and all eventually will develop MDS, with some progressing to AML. Using this mouse model, we initiated a line of research aimed at improving our understanding of the cellular and molecular pathogenesis of MDS and its progression to AML.

First, in a bone marrow transplantation model, we found that the MDS-initiating cells are confined to the Lin-;Sca-1+;c-Kit++ (LSK) compartment, a subpopulation of cells enriched for HSCs. Leukemic transformation however, does not occur in LSK cells, but in its progeny. Second, we found that clinical MDS in this Crebbp+/- mouse model is associated with a markedly increased number of mutations in all hematopoietic subpopulations tested, including LSKs. Moreover, Crebbp heterozygosity not only alters the number of mutations but also the mutation spectra, suggesting that genomic instability is part of the etiology of MDS in Crebbp+/- mice. This was determined by crossing Crebbp+/- mice to mice transgenic for the mutation reporter gene, LacI, generating Crebbp+/-,LacI+/- mice and Crebbp+/-,LacI+/- control mice. From both sets of mice, we harvested hematopoietic cells at different ages, i.e., at E14.5 (when no overt hematopoietic abnormalities are present in Crebbp+/- mice), at 6 months of age (pre-MDS stage) and 12 months (clinical MDS). Mutagenesis measurements were made at the whole tissue level and in FACS-purified bone marrow subpopulations, including LSKs and myeloid cells of increasing differentiation (namely, common myeloid progenitors (CMPs), granulocyte-monocyte progenitors (GMPs), immature (Gr1lo) and mature myeloid cells (Gr1+)). Suspected mutations were confirmed by sequencing. This study provided us with additional important insights into MDS pathogenesis: 1) In control mice, the mutant frequency in hematopoietic cells isolated from 6 month-old mice is significantly higher than that in E14.5 hematopoietic cells. 2) 6 month-old LSKs from control mice show a significantly higher mutation frequency than their CMP progeny cells. These two observations fit with the notion that MDS is HSC disease (these data show HSCs simply have a higher chance to acquire the first essential mutation event for developing MDS) and the elderly (with each cell devisions, the chances increase of having acquired a potential disease-promoting mutation). 3) 6 month-old (pre-MDS) Crebbp+/- LSKs harbor significantly fewer mutations than the control, which possibly reflects the stage of increased apoptosis (as previously published).

In summary, these data suggest that MDS and its progression to AML is not simply a process confined to the HSC compartment. Unraveling the intricate details of this disease may provide essential cues for the development of novel strategies for the treatment of this dreadful disease.

Citation Format: Ting Zhou, Ziming Cheng, Christi Walter, Vivienne I. Rebel. Novel insights into the pathogenesis of myelodysplastic syndrome using Crebbp+/- mice. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B27.

Progesterone-induced cyclin G1 inhibits the proliferation of endometrial epithelial cell and its possible molecular mechanism

Under normal conditions, progesterone inhi-bits the estrogen-induced proliferation of endometrial epithelium. Our previous studies have shown that cyclin G1 was progesterone-dependent in mouse endometrial epithelium at peri-implantation, and exogenous cyclin G1 suppressed the proliferation of endometrial cancer cells. The objectives of this study are to determine whether cyclin G1, as a negative regulator of the cell cycle, is involved in the antiproliferative action of progesterone on endometrial epithelial cells, and to explore the possible molecular mechanism of cyclin G1 inhibition. The siRNA-mediated elimination of cyclin G1 attenuated the antiproliferative action of progesterone on endometrial epithelial cells. Immunoprecipitation showed that progesterone-induced cyclin G1 could interact with PP2A to mediate its phosphatase activity. The block of PP2A activity also attenuated the antiproliferative action of progesterone on endometrial epithelial cells and increased the phosphorylated Rb. In conclusion, progesterone-induced cyclin G1 mediates the inhibitory effect of progesterone on endometrial epithelial cell proliferation possibly through the recruitment of PP2A to dephosphorylate Rb.