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. Na-Bu treatment decreased level of total pRb and phosphorylated form of pRb and caused specific dephosphorylation at Ser 249/Thr 252 and Ser 567. In the untreated and Na-Bu treated cells (when present), pRb was localised in the nucleus. Moreover, in Na-Bu treated cells the nucleus appeared highly condensed as compared to untreated cells. Results of the present study indicated that Na-Bu treatment modulated pRb phosphorylation status and caused apoptotic cell death in VS tumors.

The effect of epidermal growth factor & platelet-derived growth factors on wound healing process.

BACKGROUND & OBJECTIVES: Various growth factors play significant roles during the process of wound healing. A systematic study was carried out to evaluate the effects of topically applied epidermal growth factor (EGF) and platelet-derived growth factors (PDGF-BB, PDGF-AB, PDGF-AA) in various concentrations on wound healing. Various combinations of these growth factors were also studied to find the best combination for wound healing. METHODS: Wounds were created on a mouse model. Various concentrations and combinations of EGF and PDGFs were applied topically and the effects on wound healing were monitored visually. RESULTS: EGF, PDGF-AB and PDGF-BB when applied alone or in combination, healed the wounds in significantly less time and with less scar tissue formation compared to the controls. The best results were obtained with a combination of EGF (10 ng) and PDGF-BB (15 ng). PDGF-AA even at the maximum concentration of 20 ng did not enhance the wound repair process. A combination of PDGF-AA (20 ng) with EGF (10 ng) did not enhance the wound repair process either. INTERPRETATION & CONCLUSION: Topically applied EGF, PDGF-AB and PDGF-BB enhanced the wound repair process and had a role in decreasing the formation of scar tissue. PDGF-AA either alone or in combination with EGF did not enhance the wound repair process significantly. It appears that PDGF-AA might be limiting the EGF-mediated wound repair and such observation has not been previously reported in studies on wound healing using topically applied growth factors.