Expression of c-erbB-4/HER4 is regulated in T47D breast carcinoma cells by retinoids and vitamin D3.

Nuclear steroid/retinoid and memgbrane c-erbB receptor tyrosine kinase signaling control proliferation and differentiation of mammary epithelial cells. Recently, we reported that retinoic acids are efficient repressors of c-erbB-2 and -3, but not of c-erbB-1 gene expresson. Here we demonstrate that retinoid acid- mediated growth inhibition is accompanied with reduced expression of c-erbB-4/HER4 in T47D breast cancer cells as determined by FACS, Western, and RT-PCR. All-trans and 9-cis retinoic acid reduce c-erbB-4 expression to 30%-60% of control, depending on the concentration. Dexamethasone (Dex) is inactive on D3 (D3), in contrast, acts as a strong inducer, elevation more that twofold at the mRNA, but does not significantly affect cell growth. We concolude that retinoic acids are efficient growth inhibitors and repressors of cell growth and c-erbB-4, whereas D3 represents a highly efficient inducer of c-erbB-4 expression with affecting cell proliferation.     

PspA adopts an ESCRT-III-like fold and remodels bacterial membranes

1. Download : Download high-res image (323KB)
2. Download : Download full-size image

     

La fertilité chez le blessé médullaire. Effet du niveau de la lésion médullaire

The majority of spinal cord injured males cannot procreate naturally due to anejaculation as well as abnormal sperm characteristics. Treatment of this impaired fertility must be associated with treatment of neurogenic urinary tract disorders, bowel dysfunction and spasticity. The level of the spinal lesion and the spinal cord injury syndrome influence the possibility of inducing reflex ejaculation by penile vibratory stimulation and sperm quality.     

Secondary structure analysis of adenovirus tripartite leader

RNA secondary structure analysis was performed to understand the translation function of the adenovirus tripartite leader, a 200-nucleotide 5' noncoding region found on all late viral mRNAs. The tripartite leader facilitates the translation of viral mRNAs at late but not early times after infection and eliminates the normal requirement for the eukaryotic initiation factor 4F or cap binding protein complex. Secondary structures were determined by probing 5' or 3' end-labeled tripartite leader RNAs under nondenaturing conditions with various single strand-specific nucleases, and the information was used to generate a potential model structure. The resulting structure is attractive since it may explain the unusual translation behavior conferred by the tripartite leader. We demonstrate that the first leader segment is predominantly single-stranded, a property consistent with the ability to enhance translation and provide independence from cap binding protein complex. In contrast, the remaining two leader segments form a moderately stable base-paired structure, except for a large hairpin loop. To confirm these findings, the secondary structure of the tripartite leader was also probed when it was attached to a large segment of a messenger RNA and was found to be very similar to that of the individual leader RNA. These findings suggest several possible mechanisms to account for the translation activity of the tripartite leader.     

Renal calcium binding protein in the diabetic and vitamin D-depleted rat.

A calcium binding protein has been purified 220 fold from rat kidney. The molecular weight of this protein (26 000-28 000) is more than double that of the duodenal calcium binding protein of the rat. In response to the stimuli of both streptozotocin diabetes and depletion and repletion with vitamin D, changes in the renal protein are minimal. This contrasts markedly with responses of the duodenal protein to the same stimuli: (a) there was marked depression of duodenal calcium binding protein by vitamin D depletion and diabetes; (b) duodenal calcium binding protein was restored by vitamin D treatment of depleted rats. The renal protein appears to be identical with a previously described 28 000 molecular weight protein from the kidney purified by a different technique (Hermsdorf, C.L. and Bronner, F. (1975) Biochim. Biophys. Acta 379, 553-561). In contrast to findings of the current study, previous investigators were unable to isolate the protein from vitamin D-deficient rats and postulated vitamin D dependence. The protein activator of cyclic AMP phosphodiesterase is a calcium binding protein found in many tissues including kidney. Based on lack of response to stimuli we used and similarity in method of isolation and properties, our renal calcium binding protein may be this protein activator.     

Burden of disease due to cancer in a Southern Brazilian state

Background: Despite the considerable epidemiological relevance of cancer in developing countries, there are very few studies of the burden related to cancer. The aim of this study was to present and discuss data from a burden-of-cancer study performed in a Southern Brazilian state. Methods: An epidemiological study of ecological design was performed to calculate the disability-adjusted life year (DALY) index. The study was based on records of individuals admitted and treated for cancer in the Brazilian National Health System Hospitals, or individuals who had died of cancer while residing in the state of Santa Catarina in 2008. Results: A total of 73,872.9 DALYs were estimated, which generated a rate of 1220.5 DALYs/100,000 inhabitants. The highest DALYs were those for cancer of the trachea, bronchus and lung with 179.0/100,000 inhabitants, gastric cancer with 101.7/100,000 inhabitants, and breast cancer with 99.7/100,000 inhabitants. The percentage contribution of the DALY component varied according to cancer type; however, mortality was the major component in all types. The highest rates were observed in 60–69-year-olds with 6071.3/100,000 inhabitants, in 70–79-year-olds with 5095.4/100,000 inhabitants, and in 45–59-year-olds with 3189.0 DALY/100,000 inhabitants; 53.7% of DALYs occurred in males. Conclusions: The greatest burden of disease due to cancer in Santa Catarina was attributed to cancer of the trachea, bronchus and lung, followed by gastric and breast cancers. The mortality component was responsible for the greatest burden.