Sodium butyrate modulates pRb phosphorylation and induces cell death in human vestibular schwannomas in vitro.

In the present study, effect of Na-Bu on the pRb phosphorylation was analysed in the primary cultures of 12 VS tumors. Primary cultures of VS tumors were established from the fresh tumor tissues removed surgically and were treated with Na-Bu. Na-Bu treatment for 48 h led to morphological changes and apoptotic cell death in VS tumor cells.

Tyrosine phosphorylation of EGF-R and PDGF-R proteins during acute cutaneous wound healing process in mice.

The effect of topical application of epidermal growth factor (EGF) and platelet-derived growth factors (PDGFs) on the levels of EGF-R and PDGF-R proteins and their tyrosine phosphorylation were analyzed during an acute cutaneous wound healing process in mice. The growth factor-treated wounds had optimum levels of receptor proteins as early as day 1 compared with the control, which had only a basal level. Analysis of the tyrosine phosphorylation of the receptor proteins in control and growth factor-treated wounds indicated that they were phosphorylated until day 5 after wounding.

Altered structure and deregulated expression of the tumor suppressor gene retinoblastoma (RB1) in human brain tumors.

A total of 40 human brain tumor samples were analyzed for tumor-specific alterations at the RB1 gene locus. Gliomas were more prevalent in younger males and meningiomas in older females. Southern blot analysis revealed loss of heterozygosity (LOH) at the intron 1 locus of RB1 gene in 19.

Age dependent phosphorylation and deregulation of p53 in human vestibular schwannomas.

Tumor-specific alterations at the p53 gene locus in 30 human vestibular schwannomas (VS) comprising 10 confirmed NF2 cases and 20 sporadic cases were analyzed. We found loss of heterozygosity (LOH) at the first intron of the p53 gene locus in 54% of the informative cases. This is the first report showing LOH at the p53 gene locus in a significant number of human VS and both sporadic and NF2 cases show the LOH event.