Protein based approach to identify key players in the control of globin gene switching

Abstract

Elevated foetal haemoglobin (HbF) levels are known to lessen the severity of symptoms associated with disorders of β-globin which consequently improves the quality of life of patients affected with such disorders. To date the only treatment for β-thalassaemia remains the life-long blood transfusions which may bring about other complications due to subsequent iron accumulation in the body. In order to develop pharmacological and molecular therapies aimed at increasing HbF levels, an understanding of the mechanisms responsible for the regulation of the switch from foetal to adult haemoglobin during development is required. KLF1, which is a key regulator in the switching of γ to β-globin, directly drives expression of other transcription molecules which are necessary in the switching process, namely BCL11A and ZBTB7A. These are key repressors of foetal γ-globin gene expression and hence, providing a mechanism by which these key molecules can be silenced, can prove to be a fruitful approach in the development of new strategies targeted to increase HbF levels in patients. Other approaches towards increasing the HbF level in patients suffering from haemoglobinopathies, is by the pharmacological induction of the γ-globin gene. However, the detrimental health side-effects associated with these pharmacological inducing agents leaves their role questionable. Throughout this study, the effects of 3 novel compounds and their ability to alleviate HbF levels were investigated. Quantification of the different haemoglobin levels present in K562 cell lysates after exposure to these compounds was then performed using Western blotting. It was identified that in fact, these compounds exerted an effect on the γ-globin gene and hence, this data strongly suggested that these novel compounds under study, could play a role in increasing HbF levels in adults with β-haemoglobinopathies, with the possibility of being associated with less toxic side-effects.