Vil-Cre specific Schlafen 3 knockout mice exhibit sex-specific differences in intestinal differentiation markers and Schlafen family members expression levels

The intestinal epithelium requires self-renewal and differentiation in order to function and adapt to pathological diseases such as inflammatory bowel disease, short gut syndrome, and ulcers. The rodent Slfn3 protein and the human Slfn12 analog are known to regulate intestinal epithelial differentiation. Previous work utilizing a pan-Slfn3 knockout (KO) mouse model revealed sex-dependent gene expression disturbances in intestinal differentiation markers, metabolic pathways, Slfn family member mRNA expression, adaptive immune cell proliferation/functioning genes, and phenotypically less weight gain and sex-dependent changes in villus length and crypt depth. We have now created a Vil-Cre specific Slfn3KO (VC-Slfn3KO) mouse to further evaluate its role in intestinal differentiation. There were increases in Slfn1, Slfn2, Slfn4, and Slfn8 and decreases in Slfn5 and Slfn9 mRNA expression that were intestinal region and sex-specific. Differentiation markers, sucrase isomaltase (SI), villin 1, and dipeptidyl peptidase 4 and glucose transporters, glucose transporter 1 (Glut1), Glut2, and sodium glucose transporter 1 (SGLT1), were increased in expression in VC-Slfn3KO mice based on intestinal region and were also highly female sex-biased, except for SI in the ileum was also increased for male VC-Slfn3KO mice and SGLT1 was decreased for both sexes. Overall, the variations that we observed in these VC-Slfn3KO mice indicate a complex regulation of intestinal gene expression that is sex-dependent.

Trends and instigators among young adolescent suicide in the United States

OBJECTIVES

The present investigation examined the role of factors involved in suicide ideation and suicide attempt using a nationally representative sample of US high school students.

METHODS

Data were collected from students in Grades 9-12 as part of the Youth Behavioral Survey (n = 11,328). Logistic regression models were used to examine factors associated with suicide ideation and suicide attempt. Variables included demographic characteristics (grade, sex, and race), psychosocial factors (physical fighting, sexual violence, sports participation, bullying, and electronic bullying), and substance use (cigarette usage, marijuana usage, and alcohol usage).

RESULTS

The factor most associated with suicide ideation was bullying (either electronic or physical), whereas the factor most associated with suicide attempt was sexual violence followed closely by physical bullying.

CONCLUSIONS

The multitude of instigators and commonality among gender, ethnicity, and socio-economic status give an indication of how to prevent suicide and who to target information regarding the hazards of suicide.

Simultaneous Quantitative Detection of Relevant Biomarkers in Breast Cancer by Quantitative Real-Time PCR

The assessment of ERα, PgR and HER2 status is routinely performed today to determine the endocrine responsiveness of breast cancer samples. Such determination is usually accomplished by means of immunohistochemistry and in case of HER2 amplification by means of fluorescent in situ hybridization (FISH). The analysis of these markers can be improved by simultaneous measurements using quantitative real-time PCR (Qrt-PCR). In this study we compared Qrt-PCR results for the assessment of mRNA levels of ERα, PgR, and the members of the human epidermal growth factor receptor family, HER1, HER2, HER3 and HER4. The results were obtained in two independent laboratories using two different methods, SYBR Green I and TaqMan probes, and different primers. By linear regression we demonstrated a good concordance for all six markers. The quantitative mRNA expression levels of ERα, PgR and HER2 also strongly correlated with the respective quantitative protein expression levels prospectively detected by EIA in both laboratories. In addition, HER2 mRNA expression levels correlated well with gene amplification detected by FISH in the same biopsies. Our results indicate that both Qrt-PCR methods were robust and sensitive tools for routine diagnostics and consistent with standard methodologies. The developed simultaneous assessment of several biomarkers is fast and labor effective and allows optimization of the clinical decision-making process in breast cancer tissue and/or core biopsies.

Expression of adrenomedullin in adipose tissue of lean and obese women

OBJECTIVE

Adrenomedullin (AM), a potent vasodilatator and antioxidative peptide, was shown recently to be expressed by adipose tissue. The aim of our study was to investigate the precise localization of AM within human adipose tissue, and to examine AM regulation in obesity.

DESIGN

Subcutaneous (SC) and omental (OM) adipose tissues from 9 lean and 13 obese women were profiled for AM expression changes. Preadipocytes from human adipose tissue were isolated and differentiated under defined adipogenic conditions.

METHODS

AM expression was analyzed by immunohistochemistry, in situ hybridization and quantitative RT-PCR.

RESULTS

A strong AM expression was observed in vessel walls, stromal cell clusters and isolated stromal cells, some of them being CD 68 positive, whereas mature adipocytes were not labeled. Calcitonin receptor-like receptor and receptor activity-modifying proteins (RAMP) 2 and RAMP 3 were expressed in vessel walls. In vitro, preadipocytes of early differentiation stages spontaneously secreted AM. No difference in AM localization was found between SC and OM adipose tissue. AM levels in SC tissue did not differ between lean and obese subjects. By contrast, AM levels in OM tissue were significantly higher in obese as compared with lean women. Moreover, we found a positive relationship between OM AM and tumor necrosis factor alpha mRNA levels and AM-immunoreactive area in OM tissue followed the features of the metabolic syndrome.

CONCLUSION

Stromal cells from human adipose tissue, including macrophages, produce AM. Its synthesis increased in the OM territory during obesity and paralleled the features of the metabolic syndrome. Therefore, AM should be considered as a new member of the adipokine family.

Molecular profiles of prostate cancer versus today’s diagnostic tools

14659

Background: Tumor size, nodal status, the Gleason grading system and serum PSA values are today’s available prognostic tools of localized prostate cancer and the only help for adjuvant therapy. Based on the results of a feasibility study we continued the evaluation of the recently developed prognostic molecular signature. Methods: Of 60 CaP patients, who underwent primary prostatectomy in 2003 to 2005, fresh frozen samples of the tumor were asserved. The RNA extracted from cryocuts was tested. The quantitative RNA expression levels of 90 relevant genes involved in the different tumor hallmarks were simultaneously assessed. Results: Unsupervised agglomerative clustering of the obtained molecular profiles revealed different signatures. Correlations between these groups and the known TNM staging as well as Gleason scores were strongly present. Of interest was that all recurrences observed within this short period of time were found in a single cluster expressing higher levels of proliferation markers. Conclusions: The molecular profile of primary prostate cancer by quantitative RT-PCR is a powerful tool describing the biology of an individual tumor. Gene expression profiling can be precisely quantified and seems to be better reproducible than pathological judgments of the Gleason scores. Moreover, the gene panel is partially based on drug target genes and therefore of predictive value. Finally the method could be applied also in core biopsies.

[Table: see text]

Simultaneous quantitative detection of relevant biomarkers in breast cancer by quantitative real-time PCR

The assessment of ERa, PgR and HER2 status is routinely performed today to determine the endocrine responsiveness of breast cancer samples. Such determination is usually accomplished by means of immunohistochemistry and in case of HER2 amplification by means of fluorescent in situ hybridization (FISH). The analysis of these markers can be improved by simultaneous measurements using quantitative real-time PCR (Qrt-PCR). In this study we compared Qrt-PCR results for the assessment of mRNA levels of ERa, PgR, and the members of the human epidermal growth factor receptor family, HER1, HER2, HER3 and HER4. The results were obtained in two independent laboratories using two different methods, SYBR Green I and TaqMan probes, and different primers. By linear regression we demonstrated a good concordance for all six markers. The quantitative mRNA expression levels of ERa, PgR and HER2 also strongly correlated with the respective quantitative protein expression levels prospectively detected by EIA in both laboratories. In addition, HER2 mRNA expression levels correlated well with gene amplification detected by FISH in the same biopsies. Our results indicate that both Qrt-PCR methods were robust and sensitive tools for routine diagnostics and consistent with standard methodologies. The developed simultaneous assessment of several biomarkers is fast and labor effective and allows optimization of the clinical decision-making process in breast cancer tissue and/or core biopsies.

Different prediction of distant recurrence risk in primary breast cancer patients stratified by ER and ERBB2 status

20120

Background: Molecular profiling recently defined biological characteristics of several long-recognized breast cancer subtypes including ER-positive (luminal subtype), ER-negative/ERBB2-positive (ERBB2 subtype) and ER-negative/ErBB2-negative (basal-like subtype). Each of these particular subtypes has different impact on patient outcome and should be therefore taken in consideration for individual scoring calculations. Methods: The quantitative RNA expression levels of 70 relevant genes were simultaneously determined in fresh frozen samples of 317 primary breast cancer (BC) patients comprehending ER-positive (70%), ER-negative/ERBB2-positive (15%) and ERBB2-negative/ER-negative (15%) and with known follow-up data. Five years distant recurrence scoring systems were calculated by means of Cox-hazard regression models. Results: Two main prognostic scoring systems were developed: one based on genes relative to proliferation representing tumor growth and its velocity, the other based on proteases. A low proliferation score identified 30% of patients at very good prognosis (probability of distant recurrence 12%, CI: 1.5–22%) all belonging to the ER-positive subcategory as compared to cases with higher proliferation (probability of distant recurrence 31%, 32–38%). The probability to develop distant recurrence within 5 years for 30% of ERBB2-positive patients was of only 12% (CI 0–25%) when accompanied by low levels of proteases as compared to the remaining ERBB2-positive patients with a probability of recurrence of 40% (CI 22–54%). Conclusions: ER, ERBB2 and the expression levels of the few identified genes involved in tumor proliferation and invasion can be easily and precisely detected by means of QRT-PCR. This robust method allows fine tuned prognosis and gives predictive information for the treatment of individual breast cancer.

[Table: see text]

Quantitative real-time PCR does not show selective targeting of p14(ARF) but concomitant inactivation of both p16(INK4A) and p14(ARF) in 105 human primary gliomas

In many human cancers, the INK4A locus is frequently mutated by homozygous deletions. By alternative splicing this locus encodes two non-related tumor suppressor genes, p16(INK4A) and p14(ARF) (p19(ARF) in mice), which regulate cell cycle and cell survival in the retinoblastoma protein (pRb) and p53 pathways, respectively. In mice, the role of p16(INK4A) as the critical tumor suppressor gene at the INK4A locus was challenged when it was found that p19(ARF) only knock-out mice developed tumors, including gliomas. We have analysed the genetic status of the INK4A locus in 105 primary gliomas using both microsatellite mapping (MSM) and quantitative real-time PCR (QRT-PCR). Comparison of the results of the two methods revealed agreement in 67% of the tumors examined. In discordant cases, fluorescence in situ hybridization (FISH) analysis was always found to support QRT-PCR classification. Direct assessment of p14(ARF) exon 1beta, p16(INK4A) exon 1alpha and exon 2 by QRT-PCR revealed 43 (41%) homozygous and eight (7%) hemizygous deletions at the INK4A locus. In 49 (47%) gliomas, both alleles were retained. In addition, QRT-PCR, but not MSM, detected hyperploidy in five (5%) tumors. Deletion of p14(ARF) was always associated with co-deletion of p16(INK4A) and increased in frequency upon progression from low to high grade gliomas. Shorter survival was associated with homozygous deletions of INK4A in the subgroup of glioblastoma patients older than 50 years of age (P=0.025, Anova test single factor, alpha=0.05).

p53 gene mutation and ink4a-arf deletion appear to be two mutually exclusive events in human glioblastoma

P16 and P14ARF are two tumor suppressors encoded by the locus ink4a-arf which is frequently deleted in human tumors. Recent experiments performed with mouse embryonic fibroblasts have shown that P14ARF is an upstream regulator of the P53 pathway. This raises the question as to whether in human tumors the loss of p14arf and mutation of p53 are mutually exclusive events which segregate with genetic alterations at other loci. To examine this question we performed a multigenic analysis on 29 gliomas. We analysed p53 and p14arf in relation with five other genetic loci encoding the most frequently mutated genes in human gliomas: cdkn2a, mdm2, egfr, pten and the chromosomal regions 10q23.3 and 10q25-26. Our study shows for the first time that p53 mutations and p14arf deletions appear mutually exclusive in human glioblastoma, suggesting that they may be functionally redundant in glioma tumorigenesis. The P53 pathway is, therefore, disrupted in 81.8% of malignant gliomas (WHO grades III and IV), either by mutation of the p53 gene (31.8%) or by p14arf deletion (54.5%). These tumors further showed MDM2 overexpression (9.1%), egfr oncogene amplification/egfr overexpression (50%), pten mutations (27.3%) and loss of heterozygosity (LOH) at the chromosomal regions 10q23.3 (86.4%) and 10q25-26 (100%). These alterations did not segregate with p53 mutations or p14arf deletions, while p14arf and cdkn2a were always deleted.

N-acetylcysteine slows down ageing and increases the life span of Drosophila melanogaster

Ageing can be defined as the time-dependent decline of physiological functions of an organism. The molecular causes for the ageing process are multiple, involving both genetic and environmental factors. It has been proposed that antioxidants may positively influence the ageing process, protecting the organism against free radical-induced damage. Here we show that the antioxidant N-acetylcysteine (NAC) has a life-extending effect on Drosophila melanogaster. Dietary uptake of NAC results in a dose-dependent increase in median and maximum life span. Flies fed on 1 mg/ml NAC food live 16.6% longer; at 10 mg/ml, life span increases by 26.6%. We have examined the effect of NAC treatment on protein and RNA levels: we observe an NAC-dependent increase in absolute amounts of total RNA and ribosomal RNA, but no differences in protein levels. The NAC effect on longevity may involve differential expression of specific mRNA genes, as suggested by RNA finger-printing experiments.

Age-related changes in the mRNA expression of actin isoforms in Drosophila melanogaster

In all organisms the process of aging is characterized by a gradual loss of homeostatic maintenance functions and physiological fitness. This might be caused-in part-by a down-regulation of important housekeeping and maintenance genes. In our previous work we have shown that in Drosophila melanogaster aging is accompanied by a decrease in steady-state levels of most RNA species. This includes structural genes and housekeeping genes, though at a different level. Here we have examined age-related changes in the mRNA levels of the gene family encoding the six Drosophila actin genes. Two actin isoforms code for cytoskeletal actins and represent housekeeping genes, whereas the four muscle actin genes are expressed tissue-specifically in differentiated muscles. The results suggest that the six actin genes are differentially regulated during aging as well. The two cytoskeletal actin genes show little changes in their steady-state mRNA levels. Drastic changes are observed, however, in the mRNAs coding for muscle actins, particularly the mRNAs coding for the jump and flight muscle actins.