Determining biophysical sensitivity and specificity of quantitative magnetic resonance imaging is essential to develop effective imaging metrics of neurodegeneration. Among these metrics apparent pool size ratio (PSR) from quantitative magnetization transfer (qMT) imaging and radial diffusivity (RD) from diffusion tensor imaging (DTI) are both known to relate to histological measure of myelin density and integrity. However their relative sensitivities towards quantitative myelin detection are unknown. In this study, we correlated high-resolution quantitative magnetic resonance imaging measures of subvoxel tissue structures with corresponding quantitative myelin histology in a lipopolysacharide (LPS) mediated animal model of MS. Specifically, we acquired quantitative magnetization transfer (qMT) and diffusion tensor imaging (DTI) metrics (on the same tissue sample) in an animal model system of type III oligodendrogliopathy which lacked prominent lymphocytic infiltration, a system that had not been previously examined with quantitative MRI. We find that the qMT measured apparent pool size ratio (PSR) showed the strongest correlation with a histological measure of myelin content. DTI measured RD showed the next strongest correlation, and other DTI and relaxation parameters (such as the longitudinal relaxation rate (R1f) or fractional anisotropy (FA)) showed considerably weaker correlations with myelin content.
Quantitative magnetization transfer (qMT); Diffusion Tensor Imaging (DTI); 9.4T; White matter; Myelin; demyelination; lippopolysaccharide (LPS); Rat brain; Multiple Sclerosis (MS)
Objectives. To test the efficiency and safety of sequential application of retinoic acid (ATRA), Realgar-Indigo naturalis formula (RIF) and chemotherapy (CT) were used as the maintenance treatment in patients with acute promyelocytic leukemia (APL). Methods. This was a retrospective study of 98 patients with newly diagnosed APL who accepted two different maintenance treatments. After remission induction and consolidation chemotherapy according to their Sanz scores, patients received two different kinds of maintenance scheme. The first regimen was using ATRA, RIF, and standard dose of CT sequentially (ATRA/RIF/CT regimen), while the second one was using ATRA and low dose of chemotherapy with methotrexate (MTX) plus 6-mercaptopurine (6-MP) alternately (ATRA/CTlow regimen). The OS, DFS, relapse rate, minimal residual disease, and adverse reactions in two groups were monitored and evaluated. Results. ATRA/RIF/CT regimen could effectively reduce the chance of relapse in different risk stratification of patients, but there was no significant difference in 5-year DFS rate and OS rate between the two groups. Besides, the patients in the experimental group suffered less severe adverse reactions than those in the control group. Conclusions. The repeated sequential therapeutic regimen to APL with ATRA, RIF, and chemotherapy is worth popularizing for its high effectiveness and low toxicity.
Thrips-borne tospoviruses cause severe damage to crops worldwide. In this investigation, tobacco lines transgenic for individual WLm constructs containing the conserved motifs of the L RNA-encoded RNA-dependent RNA polymerase (L) gene of Watermelon silver mottle virus (WSMoV) were generated by Agrobacterium-mediated transformation. The WLm constructs included: (i) translatable WLm in a sense orientation; (ii) untranslatable WLmt with two stop codons; (iii) untranslatable WLmts with stop codons and a frame-shift; (iv) untranslatable antisense WLmA; and (v) WLmhp with an untranslatable inverted repeat of WLm containing the tospoviral S RNA 3′-terminal consensus sequence (5′-ATTGCTCT-3′) and an NcoI site as a linker to generate a double-stranded hairpin transcript. A total of 46.7–70.0% transgenic tobacco lines derived from individual constructs showed resistance to the homologous WSMoV; 35.7–100% plants of these different WSMoV-resistant lines exhibited broad-spectrum resistance against four other serologically unrelated tospoviruses Tomato spotted wilt virus, Groundnut yellow spot virus, Impatiens necrotic spot virus and Groundnut chlorotic fan-spot virus. The selected transgenic tobacco lines also exhibited broad-spectrum resistance against five additional tospoviruses from WSMoV and Iris yellow spot virus clades, but not against RNA viruses from other genera. Northern analyses indicated that the broad-spectrum resistance is mediated by RNA silencing. To validate the L conserved region resistance in vegetable crops, the constructs were also used to generate transgenic tomato lines, which also showed effective resistance against WSMoV and other tospoviruses. Thus, our approach of using the conserved motifs of tospoviral L gene as a transgene generates broad-spectrum resistance against tospoviruses at the genus level.
Objective: The objective of this research was to investigate the possibility of screening surface markers on rat intestinal mucosa microfold cells (M cells) by using laser capture microdissection (LCM) combined with protein chip technology. Methods: We labeled rat intestinal mucosa microfold cells with Ulex europaeus agglutinin (UEA)-1 antibody and visualized these by immunofluorescence staining. Using the Proteome Profiler rat protein chip, we analyzed the protein expression profiles of LCM M-cells compared to lymph follicle-associated epithelial (FAE) cells, and we identified potential differences to screen for marker proteins. Results: M cells can be clearly distinguished from lymphoid FAE cells under the fluorescence microscope. We successfully cut, isolated, and obtained microfold and lymph FAE cells with more than 95% homogeneity. Six differentially expressed proteins were identified through comparison of the protein chip profiles of these 2 cell types. Among these, VEGF, LIX, CNTF, and IL-1α/IL-1F1 were found to be at significantly lower levels in M cells, IL-1ra/IL-1F3 and MIG/CXCL9 appeared in significantly higher levels in M cells (P < 0.05). Conclusion: The results presented here clearly demonstrate that the combined use of LCM and protein chip technology is effective in the screening of M cell surface markers with high sensitivity and specificity. This will facilitate isolation, identification, and establishment of M cell lines, allowing further characterization of their functional properties.
Laser capture microdissection (LCM); proteomics; protein chip; M cells; marker
Objectives: MicroRNA-26b (miR-26b) has been reported to be down-regulated in a wide range of malignant tumors, However, the mechanism by which miR-26b is implicated in breast cancer tumorigenesis is incompletely understood. This study was undertaken to evaluate the expression pattern of miR-26b and characterize its biological role in human breast cancer. Methods: Reverse transcription-polymerase chain reaction (RT-PCR) was used to quantify the expression levels of miR-26b in breast cancer and adjacent non-cancerous breast tissues. MTT, colony formation assay and cell cycle assay were carried out to characterize the miR-26b function. Finally, to validate the target gene of miR-26b, luciferase reporter assay was employed, followed by RT-PCR and Western blot confirmation. Results: Here, we found that miR-26b expression was relatively downregulated in breast cancer specimens (P<0.01). Overexpression of miR-26b dramatically suppressed cell proliferation, colony formation and induced G0/G1 cell cycle arrest of MDA-MB-231 and Mcf-7 cells. Luciferase assays revealed that miR-26b directly targeted the 3’UTR of CDK8. Overexpression of miR-26b led to the downregulation of CDK8 and β-catenin expression. Similarly, CDK8 knockdown by siRNA suppressed cell growth and subsequent β-catenin expression. Conclusions: These findings suggest that miR-26b exerts a tumor suppressive role in breast cancer and the miR-26b-mediated growth inhibition is achieved through suppression of a new target gene CDK8
MiR-26b; proliferation; cell cycle; CDK8; breast cancer
Using next-generation sequencing technology alone, we have successfully generated and assembled a draft sequence of the giant panda genome. The assembled contigs (2.25 gigabases (Gb)) cover approximately 94% of the whole genome, and the remaining gaps (0.05 Gb) seem to contain carnivore-specific repeats and tandem repeats. Comparisons with the dog and human showed that the panda genome has a lower divergence rate. The assessment of panda genes potentially underlying some of its unique traits indicated that its bamboo diet might be more dependent on its gut microbiome than its own genetic composition. We also identified more than 2.7 million heterozygous single nucleotide polymorphisms in the diploid genome. Our data and analyses provide a foundation for promoting mammalian genetic research, and demonstrate the feasibility for using next-generation sequencing technologies for accurate, cost-effective and rapid de novo assembly of large eukaryotic genomes.
Background: MicroRNAs (miRNAs) are small, non-coding RNAs (18-25 nucleotides) that post-transcriptionally modulate gene expression by negatively regulating the stability or translational efficiency of their target mRNAs. The aim of this study was to investigate the expression pattern of microRNA-107 (miR-107) in human breast cancer, and its potential role in disease pathogenesis. Methods: Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to determine the expression level of miR-107 in 30 breast cancer specimens and adjacent normal breast tissues. MTT and colony formation assays, transwell and wound healing test, cell cycle assays were conducted to explore the potential function of miR-107 in human MDA-MB-231 breast cancer cells. Luciferase reporter assays were employed to validate regulation of a putative target of miR-107. The effect of modulating miR-107 on endogenous levels of this target were subsequently confirmed via Western blotting. Results: miR-107 expression was relatively decreased in breast cancer specimens compared with adjacent normal tissues (P<0.01). Overexpression of miR-107 suppressed MDA-MB-231 cell proliferation and migration, meanwhile the cells were arrested at G0/G1 phase. Luciferase assays using a reporter carrying a putative miR-107 target site in the 3’, untranslated region (3’-UTR) of CDK8 revealed that miR-107 directly targets CDK8. Overexpression of miR-107 led to downregulation of CDK8 at the mRNA and protein level, as assessed by Western blotting. Conclusions: miR-107 may play an important role in breast cancer progression, which might negatively regulate the expression of CDK8 and inhibit the proliferation and migration of MDA-MB-231 cell line.
Breast cancer; miR-107; CDK8
MicroRNAs (miRNAs) are a class of highly conserved, small endogenous single-strand non-coding RNAs. They are aberrantly expressed in the circulation and tissue of patients with cancer. Therefore, it has been suggested that they may act as key regulators of carcinogenesis. The aim of the present study was to examine the expression level of miR-195-5p in human breast cancer and its potential role in carcinogenesis. The expression level of miR-195-5p was measured in 40 breast cancer specimens and adjacent normal breast tissues by quantitative polymerase chain reaction (qPCR). Next, to explore the potential function of miR-195-5p, we used MDA-MB-231 human breast cancer cells and carried out MTT, colony formation, Transwell chamber migration and cell cycle assays. The dual-luciferase reporter assay was also performed to determine putative targets of miR-195-5p, which were validated using qPCR and western blot assays. We found that miR-195-5p expression was significantly decreased in the 40 breast cancer specimens when compared with that in the adjacent normal breast tissues (P<0.05). Overexpression of miR-195-5p inhibited cell proliferation, reduced cell colony formation, suppressed cell migration and caused an accumulation of cells in the G1 phase of the cell cycle. In the 3′-untranslated region (3′-UTR) of cyclin E1 (CCNE1), we found two putative target sites which may bind miR-195-5p, suggesting that CCNE1 is a direct target of miR-195-5p. Furthermore, through qPCR and western blot assays we showed that overexpression of miR-195-5p reduced CCNE1 mRNA and protein levels, respectively. Our study suggests that miR-195-5p may act as a tumor suppressor in breast cancer. Therefore, targeting of this miRNA may provide a novel strategy for the diagnosis and treatment of patients with this lethal disease.
microRNA; miR-195-5p; breast cancer
CDK8 is a cyclin-dependent kinase (CDK) member of the mediator complex that couples transcriptional regulators to the basal transcriptional machinery, and it has been investigated for possible tumor promoting functions. However, it is unclear whether CDK8 is involved in breast tumor cells growth. The aim of this study was to determine whether the suppression of CDK8 by small interfering RNA (siRNA) inhibits the growth of human breast cancer cell. Methods: CDK8-siRNA transfection was used to silencing the CDK8 gene in established breast cancer cell line, MDA-MB-231 and MCF-7, successful transfection being confirmed by Real-time PCR and could be shown by Western Blotting. CDK8 deletion caused significant decline in cell proliferation was observed in breast cancer cell lines as investigated by MTS assay, the number and size of the colonies formed were also significantly reduced in the absence of CDK8. Furthermore, transwell test were conducted to explore the migration of breast cancer cells. Moreover CDK8 gene knockdown arrested cell cycle. Results: CDK8 mRNA expression was reduced after transfection with CDK8-siRNA, and protein expression had a similar trend. Transfection of CDK8-siRNA suppressed breast cancer cells proliferation and migration; meanwhile the cells were arrested at G0/G1 phase. Conclusions: CDK8 plays an essential role in breast cancer progression, which might inhibit the proliferation and migration in breast cancer cells.
Breast cancer; CDK8; siRNA
MicroRNAs are a class of endogenous single strand non-coding RNAs that are involved in many important physiological and pathological processes. The purpose of this study was to examine the expression levels of miR-497 in human breast cancer and its function in MDA-MB-231 breast cancer cells.
Quantitative polymerase chain reaction was used to measure the expression levels of miR-497 in 40 breast cancer specimens and adjacent normal breast tissues. MTT assays, colony formation assays, wound healing assays, transwell assays and cell cycle assays were used to explore the potential function of miR-497 in MDA-MB-231 breast cancer cells. Dual-luciferase reporter assays were performed to analyze the regulation of putative target of miR-497, and western blot assays were used to validate the dual-luciferase results.
The expression of miR-497 in breast cancer specimens was lower than adjacent normal tissues (P < 0.05). Overexpression of miR-497 inhibited cellular growth, suppressed cellular migration and invasion, and caused a G1 arrest. Dual-luciferase reporter assays showed that miR-497 binds the 3′-untranslated region (3′-UTR) of cyclin E1, suggesting that cyclin E1 is a direct target of miR-497. Western blot assays confirmed that overexpression of miR-497 reduced cyclin E1 protein levels.
MiR-497 may act as a tumor suppressor gene in breast cancer. Inhibited cellular growth, suppressed cellular migration and invasion, and G1 cell cycle arrest were observed upon overexpression of miR-497 in cells, possibly by targeting cyclin E1. These results indicate miR-497 could be considered a therapeutic target for the development of treatment for breast cancer.
MiR-497; Breast cancer; Cyclin E1
Background: NIN/RPN Binding protein 1 homologue (NOBp1), encoded by NOB1 gene, was reported to play an essential role in the oncogenesis and prognosis of carcinomas. We conducted a study to reveal its expression and clinical significance in breast infiltrating ductal carcinoma. Methods: To explore the relationship between NOB1 expression and the clinical TNM (cTNM), 162 patients who undergone surgery were involved in the study. Compared to healthy tissues, abnormal localization and higher level of NOB1 in tumor cells was observed by Immunohistochemistry staining. Real-time PCR and western-blotting verified the up-regulation of NOB1 in carcinoma individuals. Results: A significant correlation between high level of NOB1 and the T stage, lymph node metastasis and cTNM was shown. Furthermore, patients with higher level of NOB1 predicted a declined overall survival (OS). Notably, multivariate analyses by Cox’s proportional hazard model revealed that expression of NOB1 was an independent prognostic factor in breast infiltrating ductal carcinoma. Conclusions: In summary, our present study clarify that the aberrant expression of NOB1 in breast infiltrating ductal carcinoma is possibly involved with tumorigenesis and development, and the NOB1 protein could act as a potential biomarker for prognosis assessment of breast infiltrating ductal carcinoma. Related mechanism is worthy of further investigation.
Breast cancer; NOB1 protein; immunohistochemistry; tissue microarray
Techniques for expanding skin and soft tissue are widely used to repair damaged areas since they facilitate the provision of new, additional skin tissue with similar quality, texture and color to that surrounding the defective area. Conventional expansion techniques involve placing expanders under the normal skin adjacent to a lesion. However, these techniques may involve additional incisions, complications with blood supply and ‘dog-ear’ deformities and may result in a low utilization rate of the expanded tissue. When reconstructing small defects that may not be sutured directly, these shortcomings, particularly the requirement to make additional incisions, limit the application of conventional techniques. The current study presents a novel approach to expansion called the ‘expansion in-situ’ technique. In this technique, the lesion is used as the center for expansion and expanders of optimal size are implanted under the lesion and surrounding normal soft tissue. Following expansion, the damaged area is excised directly. In order to avoid poor healing of the incision made during expander implantation, the overlapping suturing of both cut sides is conducted. This enlarges the contact area of both sides of the incision, thereby avoiding incision dehiscence and increasing wound healing during the expansion process. Between August 2006 and July 2011, the expansion in-situ technique was applied in 10 cases involving either nevus excision or scar removal. All 10 cases were treated successfully. Five of the cases were followed up over 1–3 years. The ‘expansion in-situ’ technique is likely to be useful for avoiding additional incisions and improving the utilization rate of expanded skin flaps.
soft tissue expansion; incision dehiscence; expansion in-situ; additional incision; cicatrix
MicroRNAs (miRNAs) are small, non-coding RNAs (20–24 nucleotides) that post-transcriptionally modulate gene expression by negatively regulating the stability or translational efficiency of their target mRNAs. The aim of this study was to investigate the expression pattern of microRNA-26b (miR-26b) in human breast cancer, and its potential role in disease pathogenesis.
Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to determine the expression level of miR-26b in 38 breast cancer specimens and adjacent normal breast tissues. MTT assays were conducted to explore the impact of miR-26b overexpression on the proliferation of human MDA-MB-231 breast cancer cells. Luciferase reporter assays were employed to validate regulation of a putative target of miR-26b. The effect of modulating miR-26b on endogenous levels of this target were subsequently confirmed via qRT-PCR and Western blot.
MiR-26b expression was relatively decreased in breast cancer specimens compared with adjacent normal tissues (P<0.01). Overexpression of miR-26b suppressed MDA-MB-231 cell growth. Luciferase assays using a reporter carrying a putative miR-26b target site in the 3' untranslated region of PTGS2 revealed that miR-26b directly targets PTGS2. Overexpression of miR-26b led to downregulation of PTGS2 at the mRNA and protein level, as assessed by qRT-PCR and Western blot. Targeted knockdown of PTGS2 by siRNA significantly inhibited the proliferation of MDA-MB-231 breast cancer cells.
MiR-26b may act as a tumor suppressor in breast cancer. The overexpression of miR-26b inhibits cellular growth by targeting PTGS2, suggesting its use as a potential therapeutic target for breast cancer.
MiR-26b; Proliferation; PTGS2; Breast cancer
We aimed to report our successful use of frontalis muscle flap suspension for the correction of congenital blepharoptosis in early age children.
This retrospective study included 61 early age children (41 boys, 20 girls) with an average age of 6 years (range, 3–10 years) with congenital blepharoptosis who received surgery during the period from March 2007 to January 2011. There were 39 cases of unilateral blepharoptosis and 22 cases of bilateral blepharoptosis, thus a total of 83 eyes were affected. If patient had bilateral blepharoptosis, both eyes were operated on in the same surgery. Patients were followed for 3 months to 5 years. The procedure was performed without complications in all cases.
The postoperative healing grade was good in 81 eyes (97.6%); the correction of blepharoptosis was satisfactory, the double eyelid folds were natural and aesthetic, the eyelid position and the curvature were ideal, and the eyes were bilaterally symmetrical. The postoperative healing grade was fair in 2 eyes (2.4%); blepharoptosis was improved compared with that before surgery. At discharge, lagophthalmos was noted in 10 eyes of which 4 cases resolved by the last follow-up. The remaining 6 cases were mild. Eleven eyes received reoperation for residual ptosis after the first surgery. The curvature of the palpebral margin was not natural in 4 eyes. These unnatural curvature possibly was caused by an excessively low lateral fixation point or postoperative avulsion.
Frontalis muscle flap suspension under general anesthesia for the correction of congenital blepharoptosis in early age children can achieve good surgical results.
Successful eyelid reconstructions have been reported when using an axial nasal chondromucosal flap based on the dorsal nasal artery. The present study aimed to present a detailed anatomical description of the blood supply of the lateral nasal region and the angular artery, in order to propose the angular vessels as a new vascular pedicle for the island nasal chondromucosal flap. A total of 11 cadavers (22 hemi-faces) were examined. Observations with regard to the origin, course and distribution patterns of the angular artery were recorded. Based on the anatomical study findings, the angular vessels were proposed as a vascular source for the island nasal chondromucosal flap. Observations with regard to the varying origins of the angular artery were categorized into four types. The course of the angular artery along the nasojugal fold was constant. The angular artery branched off into the upper two-thirds of the lateral nasal region and anastomosed with the other vascular branches on the nasal dorsum. Clinically, reconstruction of a full-thickness defect of the lower eyelid was successfully performed by using this composite flap based on the angular vessels and an adjacent orbicularis oculi myocutaneous flap. Satisfactory esthetic outcomes were obtained for the donor and recipient sites. The angular artery is a good vascular source for an island nasal chondromucosal flap. The flap may be created safely and successfully in clinic. Island nasal chondromucosal flaps and nasolabial groove skin flaps based on the angular vessels may be designed simultaneously for use on full-thickness defects of the eyelid.
eyelid reconstruction; chondromucosal flap; angular vessels
Existing methods for predicting protein solubility on overexpression in Escherichia coli advance performance by using ensemble classifiers such as two-stage support vector machine (SVM) based classifiers and a number of feature types such as physicochemical properties, amino acid and dipeptide composition, accompanied with feature selection. It is desirable to develop a simple and easily interpretable method for predicting protein solubility, compared to existing complex SVM-based methods.
This study proposes a novel scoring card method (SCM) by using dipeptide composition only to estimate solubility scores of sequences for predicting protein solubility. SCM calculates the propensities of 400 individual dipeptides to be soluble using statistic discrimination between soluble and insoluble proteins of a training data set. Consequently, the propensity scores of all dipeptides are further optimized using an intelligent genetic algorithm. The solubility score of a sequence is determined by the weighted sum of all propensity scores and dipeptide composition. To evaluate SCM by performance comparisons, four data sets with different sizes and variation degrees of experimental conditions were used. The results show that the simple method SCM with interpretable propensities of dipeptides has promising performance, compared with existing SVM-based ensemble methods with a number of feature types. Furthermore, the propensities of dipeptides and solubility scores of sequences can provide insights to protein solubility. For example, the analysis of dipeptide scores shows high propensity of α-helix structure and thermophilic proteins to be soluble.
The propensities of individual dipeptides to be soluble are varied for proteins under altered experimental conditions. For accurately predicting protein solubility using SCM, it is better to customize the score card of dipeptide propensities by using a training data set under the same specified experimental conditions. The proposed method SCM with solubility scores and dipeptide propensities can be easily applied to the protein function prediction problems that dipeptide composition features play an important role.
The used datasets, source codes of SCM, and supplementary files are available at http://iclab.life.nctu.edu.tw/SCM/.
Confronting developmental tasks and challenges associated with bridging two different cultures, Asian American adolescent girls face increasing risks for substance use. Identifying risk and protective factors in this population is essential, particularly when those factors can inform preventive programs. Guided by family interaction theory, the present cross-sectional study explored the associations of psychological and familial factors with use of alcohol, prescription drugs, and other drugs among early-adolescent Asian American girls. Between August 2007 and March 2008, 135 pairs of Asian American girls (mean age 13.21 years, SD = 0.90) and their mothers (mean age 39.86 years, SD = 6.99) were recruited from 19 states that had significant Asian populations. Girls and mothers each completed an online survey. Relative to girls who did not use substances, girls who did had higher levels of depressive symptoms, perceived peer substance use, and maternal substance use. Multiple logistic regression modeling revealed that they also had significantly lower levels of body satisfaction, problem-solving ability, parental monitoring, mother-daughter communication, family involvement, and family rules about substance use. Household composition, acculturation, and academic achievement were not associated with girls’ substance use. These findings point to directions for substance abuse prevention programming among Asian American girls.
Asian Americans; substance use; female; adolescents; risk factors; family
Background: Ras signaling is known to be critical for tumor progression.
Results: Ras-PI3K regulates H3K56 acetylation (H3K56ac) via the MDM2-dependent degradation of CBP/p300. H3K56ac is revealed to be associated with the transcription, proliferation, and migration of tumor cells.
Conclusion: H3K56 acetylation is a critical component of the oncogenic Ras-PI3K pathway.
Significance: The Ras-PI3K-AKT-H3K56ac pathway is a potential target for cancer therapy.
It is well established that the small GTPase Ras promotes tumor initiation by activating at least three different mediators: Raf, PI3K, and Ras-like (Ral) guanine nucleotide exchange factors. However, the exact mechanisms that underlie these different Ras signaling pathways, which are involved in tumor progression, remain to be elucidated. In this study, we report that the Ras-PI3K pathway, but not Raf or the Ral guanine nucleotide exchange factors, specifically targets the acetylation of H3 at lysine 56 (H3K56ac), thereby regulating tumor cell activity. We demonstrate that the Ras-PI3K-induced reduction in H3K56ac is associated with the proliferation and migration of tumor cells by targeting the transcription of tumor-associated genes. The depletion of the histone deacetyltransferases Sirt1 and Sirt2 rescues the Ras-PI3K-induced decrease in H3K56ac, gene transcription, tumor cell proliferation, and tumor cell migration. Furthermore, we demonstrate that the Ras-PI3K-AKT pathway regulates H3K56ac via the MDM2-dependent degradation of CREB-binding protein/p300. Taken together, the results of this study demonstrate that the Ras-PI3K signaling pathway targets specific epigenetic modifications in tumor cells.
CBP; Epigenetics; Histone Modification; p300; Phosphatidylinositol 3-Kinase; Ras; Signal Transduction; MDM2; Histone Acetylation
Rarely has substance use prevention programming targeted Asian American adolescents. Using a focus group methodology, we explored perceptions of substance use and preferences for prevention programming among 31 Asian American adolescents in New York City. Participants considered substance use common in the community. Factors contributing to substance use among Asian American adolescents (e.g., peer pressure, pressure to achieve, family factors, and community influence) were identified, and the need for prevention programs tailored for the Asian American community was highlighted. Participants discussed preferred program content, delivery settings, and recruitment and retention strategies. Despite the favorable attitude for family-based prevention programming, participants raised potential issues concerning the feasibility of such a program. Study findings facilitate understanding of Asian American adolescents’ substance use behavior and shed light on prevention program development for this underserved population.
Asian Americans; adolescents; substance use; prevention; model minority; parents
Since the introduction of the theory of tumour stem cells (TSCs), the liver cancer stem cell (LCSC)-like cells have become one of the focuses in the research on liver cancer.
Materials and methods.
In this study, CD90+ cells were applied as the possible LCSC-like cells, and the miRNA and gene expression were analyzed in the CD90+ HepG2 cells. The pilot study showed miR-548c-5p exerted potential effect on the CD90+ HepG2 cells and was thereafter applied for the further study. CD90+ HepG2 cells were assigned to miR-548c-5p mimic transfection group and control group. MTT assay was performed to detect the proliferation of CD90+ HepG2 cells. The migration and invasion abilities were examined by wound healing assay and transwell migration assay, respectively. A detection of apoptosis was performed by fluorescence microscopy.
Our results showed that caspase-3 and bcl-2 were down-regulated while caspase-8 was up-regulated in the CD90+ HepG2 cells. Moreover, the miR-548c-5p transfection could down-regulate the expression of β-catenin, Tg737, bcl-2, bcl-XL, and caspase-3, inhibit the proliferation, migration and invasion and promote the apoptosis of the CD90+ HepG2 cells.
Our findings indicate the imbalance between apoptosis and anti-apoptosis in the LCSC-like cells, which influence the biological features of LCSC-like cells. miRNA plays a regulatory role in the LCSC-like cells among which miR-548c-5p might be a suppressor.
liver cancer stem cells; miR-548c-5p; apoptosis; NF-κB, β-catenin
Pancreaticobiliary maljunction (PBM) is often associated with congenital choledochal cyst, protein plugs and pancreatitis. Early diagnosis and timely treatment largely depend on imaging. We assessed a series of PBM in children, comparing imaging procedure with histological and pathological findings with regard to diagnosis.
A retrospective analysis was conducted in 75 pediatric patients with PBM. PBM was defined as common channel at >5 mm. Two radiologists assess the shape of the bile duct and gallbladder, pancreatitis, surgical pathology, symptom profiles, operative notes and pathological records were compared with the imaging findings.
Dilatation of the bile duct was detected in 45 subjects out of the 46 subjects who underwent computed tomography (CT) and nine was diagnosis as PBM. Forty out of 41 subjects were revealed bile duct dilatation in ultrasonography (US). Bile duct dilatation was seen in 59 out of 60 subjects receiving magnetic resonance cholangiopancreatography (MRCP) and 39 were diagnosed as PBM. Seventy-four out of 75 subjects successfully underwent intraoperative cholangiography (IOC); a diagnosis of PBM was established in 60 cases based on IOC alone. The diagnosis rate of pediatric PBM varied significantly among the four groups (P < 0.0001). Pair-wise comparison showed a significant difference between the groups of MRCP and CT (P < 0.0001), MRCP and US (P < 0.0001), IOC and CT (P < 0.0001), IOC and US (P < 0.0001), CT and US (P = 0.0027), and there is no significant difference between the groups of IOC and MRCP (P = 0.0502).
US, IOC, CT and MRCP are valuable in showing dilatation of the bile duct and complications in pediatric PBM. MRCP is non-invasive, gives clear views of the pancreaticobiliary junction and should be the first choice for the diagnosis of PBM in children.
Pancreaticobiliary maljunction; Pediatric; Imaging; Intraoperative cholangiography
Maintaining an appropriate cellular concentration of p53 is critical for cell survival and normal development in various organisms. In this study, we provide evidence that the human E2 ubiquitin-conjugating enzyme RAD6 plays a critical role in regulating p53 protein levels under both normal and stress conditions. Knockdown and overexpression of RAD6 affected p53 turnover and transcription. We showed that RAD6 can form a ternary complex with MDM2 and p53 that contributes to the degradation of p53. Chromatin immunoprecipitation (ChIP) analysis showed that RAD6 also binds to the promoter and coding regions of the p53 gene and modulates the levels of H3K4 and K79 methylation on local chromatin. When the cells were exposed to stress stimuli, the RAD6-MDM2-p53 ternary complex was disrupted; RAD6 was then recruited to the chromatin of the p53 gene, resulting in an increase in histone methylation and p53 transcription. Further studies showed that stress-induced p53 transcriptional activation, cell apoptosis, and disrupted cell cycle progression are all RAD6 dependent. Overall, this work demonstrates that RAD6 regulates p53 levels in a “yin-yang” manner through a combination of two distinct mechanisms in mammalian cells.
Lactase is the intestinal enzyme responsible for digestion of the milk sugar lactose. Lactase gene expression declines dramatically upon weaning in mammals and during early childhood in humans (lactase nonpersistence). In various ethnic groups, however, lactase persists in high levels throughout adulthood (lactase persistence). Genetic association studies have identified that lactase persistence in Northern Europeans is strongly associated with a single nucleotide polymorphism (SNP) located 14 kb upstream of the lactase gene: −13910*C/T. To determine whether the −13910*T SNP can function in vivo to mediate lactase persistence, we generated transgenic mice harboring human DNA fragments with the −13910*T SNP or the ancestral −13910*C SNP cloned upstream of a 2 kb rat lactase gene promoter in a luciferase reporter construct. We previously reported that the 2 kb rat lactase promoter directs a post-weaning decline of luciferase transgene expression similar to that of the endogenous lactase gene. In the present study, the post-weaning decline directed by the rat lactase promoter is impeded by addition of the −13910*T SNP human DNA fragment, but not by addition of the −13910*C ancestral SNP fragment. Persistence of transgene expression associated with the −13910*T SNP represents the first in vivo data in support of a functional role for the −13910*T SNP in mediating the human lactase persistence phenotype.
lactase; gene regulation; SNP; transgenic mice