Novel mutations of CLCN7 cause autosomal dominant osteopetrosis type II (ADO-II) and intermediate autosomal recessive osteopetrosis (IARO) in Chinese patients

SUMMARY

Osteopetrosis is a group of genetic bone disorders. Mutations in the chloride channel 7 gene (CLCN7) lead to chloride channel defect, which results in autosomal dominant osteopetrosis type II (ADO-II), autosomal recessive osteopetrosis (ARO), and intermediate autosomal recessive osteopetrosis (IARO). In the present study, we identified seven novel mutations of the CLCN7 gene and reported the first case of IARO with compound heterozygous mutation in Chinese population.

INTRODUCTION

Osteopetrosis is a heritable bone disorder due to the deficiency of or function defect in osteoclasts. Mutations in the CLCN7 lead to chloride channel defects, which result in osteopetrosis with diverse severity ranging from asymptomatic or relatively mild symptoms in ADO-II to the very severe phenotype in ARO. Heterozygous mutations in CLCN7 are associated to ADO-II, while homozygous and compound heterozygous mutations in CLCN7 may result in ARO and IARO. To date, a total of 24 mutations in CLCN7 were identified in ADO-II, and only 3 mutations were identified in IARO. In the present study, we reported seven unrelated ADO-II patients and one IARO patient from Chinese population and elucidated the characteristics of CLCN7 gene mutations in these patients.

METHODS

All 25 CLCN7 exons and exon-intron boundaries from genomic DNA were amplified and sequenced in eight affected individuals suffering from ADO-II/IARO. The clinical, biochemical, and radiographic analysis were evaluated to compare the differences between ADO-II and IARO both in genotype and phenotype.

RESULTS

The results showed that there were seven novel CLCN7 mutations identified in these ADO-II/IARO patients, including six heterozygous missense mutations (p.L224R, p.S290Y, p.R326G, p.G347R, p.S473N, and p.L564P) and a novel splice mutation (p.K691FS).

CONCLUSIONS

The compound heterozygous mutations (p.L224R and p.K691FS) were firstly observed in one IARO patient. The present study would enrich the database of CLCN7 mutations and improve our understanding of this heritable bone disorder.

Online beam energy measurement of Beijing electron positron collider II linear accelerator

This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper.

Combined low dose local anesthetics and opioids versus single use of LA for transurethral urological surgery: a meta-analysis

INTRODUCTION

The combination of reduced dose of local anesthetics (LA) and highly lipid-soluble synthetic opioids for patients undergoing transurethral surgery could reduce block duration and side-effects. However, it remains unclear what are the most appropriate levels of low dose and the extent to which the side-effects could be controlled. A meta-analysis was conducted to address this concern.

MATERIALS AND METHODS

Based on twelve randomized controlled trials, this meta-analysis pooled previous results to generate integrated evidence.

RESULTS

Combined low dose of LA and opioids had similar sensory block and significantly shorter motor block duration (weighted mean difference: -39.31 min, 95% confidence interval (CI): -50.58--28.05, P < 0.00001) compared with single use of LA. There was no evidence of higher risk of analgesic failure in the combination group. In addition, combined low dose LA and opioids was associated with significantly reduced rate of postoperative hypotension (risk ratios (RR): 0.60, 95% CI: 0.37-0.96, P = 0.03) and shivering (RR: 0.27, 95% CI: 0.11-0.64, P = 0.003), but with higher rate of sedation (RR: 3.14, 95% CI: 1.02-9.66, P = 0.05).

CONCLUSION

Combined low dose LA and opioids is a better choice for patients received transurethral surgery compared with single use of intrathecal LA.

Design of charge exchange recombination spectroscopy for the joint Texas experimental tokamak

The old diagnostic neutral beam injector first operated at the University of Texas at Austin is ready for rejoining the joint Texas experimental tokamak (J-TEXT). A new set of high voltage power supplies has been equipped and there is no limitation for beam modulation or beam pulse duration henceforth. Based on the spectra of fully striped impurity ions induced by the diagnostic beam the design work for toroidal charge exchange recombination spectroscopy (CXRS) system is presented. The 529 nm carbon VI (n = 8 - 7 transition) line seems to be the best choice for ion temperature and plasma rotation measurements and the considered hardware is listed. The design work of the toroidal CXRS system is guided by essential simulation of expected spectral results under the J-TEXT tokamak operation conditions.

Abstract P4-07-13: High microRNA-621 level predicts a better response to neoadjuvant chemotherapy in breast cancer patients

Purpose: Weekly paclitaxel plus carboplatin (PCb) regimen is an effective neoadjuvant chemotherapy for breast cancer. However, some patients respond to this regimen poorly and suffer from side effects. In this study, we aimed to define the microRNA (miRNA) biomarker for predicting sensitivity to PCb chemotherapy in breast cancer patients, and to explore the potential molecular mechanisms.

Experimental Design: 81 patients with stages II and III breast cancer, who received four cycles of weekly PCb regimen preoperative chemotherapy, were included. Gene expression profiles from 31 patients was used as training set to determine differentially expressed genes (DEGs) and to predict miRNAs that may be associated with chemotherapeutic sensitivity. The other 50 patients were analyzed as validation set to test the accuracy of DEG identification and miRNAs prediction by quantitative real-time PCR. In parallel, in vitro and in vivo analyses were carried out to determine the potential mechanisms of miRNA-dependent drug sensitivity.

Results: Gene profiling analyses in the training set revealed significant correlation between high expression level of miR-345 and miR-621 and pathologic complete response (pCR) in breast cancer patients. We further validated that the expression level of miR-621 was significantly higher in tumor tissues of pCR patients than that in non-pCR patients (P = 0.01). In breast cancer cell lines, ectopic overexpression of miR-621 promoted apoptosis and increased chemosensitivity to paclitaxel and carboplatin both in vitro and in vivo. The potential miR-621-target genes were determined by TargetScan and miRNA CLIP-seq database, which were further confirmed as DEGs reversely-correlated to miR-621 in breast cancer patient samples. Among those, FBXO11 was verified as one of the direct targets of miR-621 in breast cancer cells, whose expression level negatively associated with chemosensitivity in breast cancer patients. The molecular mechanisms by which miR-621/FBXO11 axis regulates chemosensitivity may involve regulation of p53 transcriptional activity and epithelial-mesenchymal transition (EMT) in breast cancer cells.

Conclusions: Our study revealed a strong correlation between miR-621 expression and chemosensitivity in breast cancers. High level of miR-621 predicts sensitivity to PCb regimen neoadjuvant chemotherapy in breast cancer patients who tend to achieve pCR. The increased chemosensitivity may be mediated by down-regulation of FBXO11 gene, which leads to enhanced p53 transactivity and reduced EMT in breast cancer cells. Therefore, miR-621 may be used as predictive biomarker and the potential therapeutic target in breast cancer treatment.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-07-13.

Abstract P5-04-11: CDK11p58 inhibits estrogen receptor a positive breast cancer invasion via integrinb3 through repressing ERa signaling

Background: The sex steroid estrogen plays a major role in the development and progression of breast cancer. Estrogen promotes breast cancer proliferation through a number of established pathways. CDK11p58, a Ser/Thr kinase which belongs to Cell Division Cycle 2-like 1 (CDC2L1) subfamily, is associated with cell cycle progression, tumorigenesis and apoptotic signaling. In the previous study, we found that CDK11p58 interacted with estrogen receptor a (ERa) in breast tumor cells and repressed ERa transcriptional activity through promoting its ubiquitin/proteasome-mediated degradation. Here we sought to investigate the critical role of CDK11p58 in the carcinogenisis of breast cancer.

Methods and results: We measured the expression of CDK11p58 in 132 pairs of breast cancer tissues and adjacent tissues by IHC and qPCR. The mRNA and protein level of CDK11p58 were significant higher in breast cancer tissues than those in normal breast tissues. Interestingly, low expression of CDK11 was associated with lymph nodes metastasis in patients (P&lt;0.05). Using the ERa + cell lines ZR-75-30 and T47D, we found CDK11p58 could repress the migration and invasion of ERa positive breast cancer cells. We further demonstrated that mRNA of integrinb3 were dramatically repressed by CDK11p58 by the TaqMan® Metastasis Gene Expression Assays. The effect was CDK11p58 kinase activity dependent. Expression of integrinβ3 was highly related with ERa signaling. While overexpression ERa stimulates integrinβ3 expression, knockdown of ERa attenuates integrinβ3 expression. By the Dual-luciferase array and CHIP assay, we found estrogen response elements (ERE) indeed existed in integrinβ3 promoter. ERa bound to the ERE on the integrinβ3 promoter and increased its transcription.

Conclusions: Our findings provide mechanistic insights into how CDK11p58 regulated the expression of integrinβ3 to inhibit the cell invasion though repressing the signaling of ERa in a kinase activity dependent way. These data indicate that CDK11p58 is an antimetastasis gene product in breast cancer and regulation of integrinβ3 by CDK11p58 through ERa could be part of a signaling pathway that determines and explains breast cancer invasion and metastasis.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-04-11.

Note: Characteristic beam parameter for the line electron gun

We have optimized the beam parameters of line source electron gun using Stanford Linear Accelerator Centre electron beam trajectory program (EGUN), utilizing electrostatic focusing only. We measured minimum beam diameter as 0.5 mm that corresponds to power density of 68.9 kW/cm(2) at 13.5 mm in the post-anode region which is more than two-fold (33 kW/cm(2)), of the previously reported results. The gun was operated for the validation of the theoretical results and found in good agreement. The gun is now without any magnetic and electrostatic focusing thus much simpler and more powerful.

Asymmetric dimethylarginine and carotid atherosclerosis in Type 2 diabetes mellitus

BACKGROUND

Circulating asymmetric dimethylarginine (ADMA) concentration is elevated in patients with Type 2 diabetes mellitus (T2DM).

AIM

To assess the relationship between plasma ADMA concentration and carotid atherosclerosis in patients with T2DM.

SUBJECTS AND METHODS

A total of 72 newly diagnosed and untreated T2DM individuals and 72 healthy controls were studied. Carotid atherosclerosis was determined by ultrasonographically evaluated intima- media thickness (IMT) and plaque score. Plasma concentration of ADMA was measured by high-performance liquid chromatography.

RESULTS

Plasma ADMA, mean IMT, and plaque score were higher in diabetic patients compared with controls. Univariate and multivariate analyses demonstrated an independent association between ADMA and mean IMT in diabetic patients. On a multiple logistic regression analysis, ADMA was the sole predictor of carotid plaque formation (plaque score ≥1.1) (odds ratio 2.43, 95% confidence interval 1.19 to 4.94, p<0.05).

CONCLUSION

Our results suggest that increased levels of ADMA might be involved in the development of carotid atherosclerosis in T2DM.

Cordycepin as a sensitizer to tumour necrosis factor (TNF)-α-induced apoptosis through eukaryotic translation initiation factor 2α (eIF2α)- and mammalian target of rapamycin complex 1 (mTORC1)-mediated inhibition of nuclear factor (NF)-κB

Cordycepin (3'-deoxyadenosine) is one of the major bioactive substances produced by Cordyceps militaris, a traditional medicinal mushroom. Cordycepin possesses several biological activities, including both pro-apoptotic and anti-apoptotic properties. In the present report, we investigated an effect of cordycepin on the survival of cells exposed to tumour necrosis factor (TNF)-α. We found that subtoxic doses of cordycepin increased susceptibility of cells to TNF-α-induced apoptosis. It was associated with suppression of nuclear factor-κB (NF-κB), a major prosurvival component involved in TNF-α signalling. The adenosine transporter and A₃ adenosine receptor, but not A₁ and A₂ adenosine receptors, mediated both anti-NF-κB and pro-apoptotic effects. We found that cordycepin had the potential to phosphorylate eukaryotic translation initiation factor 2α (eIF2α) and that activation of eIF2α mimicked the suppressive effect of cordycepin on the NF-κB pathway. Furthermore, activation of eIF2α sensitized cells to TNF-α-induced apoptosis. To identify molecular events downstream of eIF2α, the role of mammalian target of rapamycin complex 1 (mTORC1) was examined. Selective activation of ₃eIF2α, as well as treatment with cordycepin, caused phosphorylation of mTORC1. Rapamycin, an inhibitor of mTORC1, significantly reversed the suppressive effects of eIF2α on NF-κB. These results suggest that cordycepin sensitizes cells to TNF-α-induced apoptosis, at least in part, via induction of the eIF2α-mTORC1 pathway and consequent suppression of NF-κB.

A pilot study to evaluate assisted freehand ultrasound elasticity imaging in the sizing of early breast cancer: a comparison of B-mode and AFUSON elasticity ultrasound with histopathology measurements

OBJECTIVE

This pilot study investigates the role of assisted-freehand ultrasound (AFUSON) elasticity imaging of the breast in assessing the contour, size and area of 23 early breast cancers by making comparison of AFUSON with the equivalent B-mode ultrasound images and gold standard histopathology slides.

METHODS

The B-mode, AFUSON and digitised histopathology slides of three early breast cancers were compared for contour, size and area with histopathology scans. AFUSON features that corresponded to areas of known malignant change on the histopathology slides were regarded as diagnostic. These diagnostic criteria were then applied to the B-mode and AFUSON elasticity images of all 23 breast cancers in the pilot study without having the availability of the histopathology scans for reference. Corresponding diameters were measured and the results were compared with the equivalent measurements on the scans of the histology slides. The results were tabulated in histogram form. Diagnostic confidence levels were evaluated.

RESULTS

Size dimension accuracy increased from 66% using B-mode alone to 82% using combined B-mode and AFUSON elasticity images. Tumour area accuracy was also increased. A small number of cases had a striking visual similarity of shape on AFUSON elasticity scans and histopathology slides.

CONCLUSION

In spite of the shortfalls in this study, AFUSON elasticity imaging was capable of acquiring some high-quality images that showed strong correlation between AFUSON elasticity and scans of histology slides. Further studies will be carried out to refine the technique and determine if it has a role in the diagnosis and management of breast cancer.