Dysregulated expression of Fau and MELK is associated with poor prognosis in breast cancer

Introduction  

Programmed cell death through apoptosis plays an essential role in the hormone-regulated physiological turnover of mammary tissue. Failure of this active gene-dependent process is central both to the development of breast cancer and to the appearance of the therapy-resistant cancer cells that produce clinical relapse. Functional expression cloning in two independent laboratories has identified Finkel–Biskis–Reilly murine sarcoma virus-associated ubiquitously expressed gene (Fau) as a novel apoptosis regulator and candidate tumour suppressor. Fau modifies apoptosis-controller Bcl-G, which is also a key target for candidate oncoprotein maternal embryonic leucine zipper kinase (MELK).     

Lack of expression of inhibitory KIR3DL1 receptor in patients with natural killer cell-type lymphoproliferative disease of granular lymphocytes

Background

Natural killer cell-type lymphoproliferative disease of granular lymphocytes is a disorder characterized by chronic proliferation of CD3⁻CD16⁺ granular lymphocytes. By flow cytometry analysis, we previously demonstrated a dysregulation in killer immunoglobulin-like receptor (KIR) expression in natural killer cells from patients with this lymphoproliferative disease, the activating KIR receptors being mostly expressed. We also found that patients with natural killer cell-type lymphoproliferative disease of granular lymphocytes usually had KIR genotypes characterized by multiple activating KIR genes.

Design and Methods

We investigated the mRNA levels of the KIR3DL1 inhibitory and the related KIR3DS1 activating receptors in 15 patients with natural killer cell-type lymphoproliferative disease of granular lymphocytes and in ten controls. These genes are usually expressed when present in the genome of the Caucasian population.

Results

We demonstrated the complete lack of KIR3DL1 expression in most of the patients analyzed, with the receptor being expressed in 13% of patients compared to in 90% of controls (P<0.01). Interestingly, studies of the methylation patterns of KIR3DL1 promoter showed a significantly higher methylation status (0.76 ± 0.12 SD) in patients than in healthy subjects (0.49±0.10 SD, P<0.01). The levels of expression of DNA methyl transferases, which are the enzymes responsible for DNA methylation, did not differ between patients and controls.

Conclusions

In this study we showed, for the first time, a consistent down-regulation of the inhibitory KIR3DL1 signal due to marked methylation of its promoter, thus suggesting that together with the increased expression of activating receptors, the lack of the inhibitory signal could also play a role in the pathogenesis of natural killer cell-type lymphoproliferative disease of granular lymphocytes.     

Galactocele: an unusual cause of breast enlargement in children

Galactoceles in children, either cystic or pseudotumors, are described in the literature as a rare cause of increasing breast size and can appear in males. We report a case of galactocele in a 15-month-old male, treated at our institution. The patient presented with a tumor in the right breast that had appeared 6 months earlier with no pain, signs of inflammation, or nipple secretion. Twelve cases found in the literature emphasize the importance of including galactocele in the differential diagnosis of benign breast masses in infancy.     

Change in proteoglycan metabolism is a characteristic of human patellar tendinopathy

Objective

To determine differences in the metabolism of proteoglycans and the gene expression of proteinases and their inhibitors between patellar tendons exhibiting chronic overuse tendinopathy and normal patellar tendons in humans.

Methods

Rates of loss and synthesis of proteoglycans were determined. Radiolabeled and total proteoglycans retained in and lost from the tissue were analyzed by fluorography and Western blotting. Levels of messenger RNA for matrix metalloproteinase 1 (MMP‐1), MMP‐2, MMP‐3, MMP‐9, MMP‐13, ADAMTS‐1, ADAMTS‐4, ADAMTS‐5, tissue inhibitor of metalloproteinases 1 (TIMP‐1), TIMP‐2, TIMP‐3, and TIMP‐4 were determined in fresh tissue.

Results

The rate of loss of ³⁵S‐labeled proteoglycans was greater in abnormal tendons, as was the rate of synthesis of proteoglycans. Fluorography and Western blotting revealed the presence of greater amounts of large proteoglycans (aggrecan and versican) in abnormal tendons, and these proteoglycans were rapidly lost from the matrix of abnormal tendons. There was no significant difference in the expression of ADAMTS‐1, ADAMTS‐4, ADAMTS‐5, MMP‐1, MMP‐2, MMP‐3, MMP‐13, TIMP‐2, TIMP‐3, or TIMP‐4. There was a significant increase in the expression of MMP‐9 and TIMP‐1 in abnormal tendons.

Conclusion

Our findings suggest that a change in the proteoglycan content of the extracellular matrix in abnormal tendons results from the altered metabolism of the cells, reflected in the enhanced synthesis of the large proteoglycans aggrecan and versican, and does not appear to result from changes at the level of gene expression.

     

Silicates and bone fusion

Autologous bone grafting remains the gold standard for bone grafting in clinical practice. Although it has withstood the test of time, it remains associated with multiple comorbidities. The search for an alternative bone graft substitute harnessing bone's osteoconductive, osteoinductive, and osteogenic properties remains a challenge. This article examines the various bone grafting materials currently in use and highlights the current properties and uses of silicon-substituted calcium phosphates as a competitive substitute for high cost materials used today.     

Spatial and temporal distribution of Ki-67 proliferation marker, Bcl-2 and Bax proteins in the developing human tooth

Objective

To investigate the spatial and temporal expression of proliferation Ki-67 marker, pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins during early development of the human tooth.

Materials and methods

Histological sections of eight human conceptuses, 5–10 postovulatory weeks old, were used for immunolocalization for Ki-67, Bax and Bcl-2 markers. Quantification was performed by calculating the fraction of Ki-67 positive cells, expressed as a mean ± SD, and analysed by Mann–Whitney test, Kruskal–Wallis and Dunn's post hoc test.

Results

In 6th–7th developmental weeks, the tooth germ and dental crest contained 37% of proliferating cells, which increased to 40% in the 8th week, and then decreased to 15% in the 10th week, whilst the proliferation in the ectomesenchyme subsequently dropped from 37% to 23%. Epithelial parts of the enamel organ displayed similar proliferation activity (31–36%), dental crest 10%, whilst enamel knot showed no proliferating activity. The tooth ectomesenchyme contained more proliferating cells (50%) than the jaw ectomesenchyme (35%), and both dropped to 28% in the 10th week. Ectomesenchyme between the tooth germs contained 23%, whilst the jaw ectomesenchyme contained 15% of proliferating cells. Bcl-2 expression had following pattern: strong in proliferating cells, moderate in tooth germs and dental crest, and weak in the ectomesenchyme. Bax co-expressed with Bcl-2 in the tooth germ and dental crest. In the reticulum and inner enamel epithelium Bcl-2 had prevalent expression, whilst Bax prevailed in the outer enamel epithelium and tooth ectomesenchyme.

Conclusions

Proliferating cells most likely influence growth of the tooth germ, Bcl-2 affects proliferation and differentiation of specific cell lineages, whilst Bax influences process of cell death.