Comparison of phosphorylation patterns in NSCLC cell lines after different radiation qualities.

Sara Ståhl, Johan Lengqvist, and Janne Lehtiö.

Ass. Prof Bo Stenerlöw, Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala.
Prof. Roman Zubarev, Dep. Of Biological and Medical Mass Spectrometry, Uppsala University.

High linear energy transfer (LET) radiation (i.e., charged particles or accelerated ions) have recently been applied (or planned for) in patients with NSCLC as a high dose of radiation can be given to a small area and effects on normal tissue can be limited. Little is however known about the molecular mechanisms behind the high efficiency of High LET radiation and therefore more knowledge is required. In collaboration with Ass. Prof Bo Stenerlöw, Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala we have observed that a NSCLC cell line which is resistant to low Linear energy transfer (LET) ?-IR respond to High LET charged nitrogen ions with induction of apoptosis involving activation of Bak/Bax and JNK (Viktorsson, Ståhl et al. manuscript in preparation). In this part of the project we want to discover new signalling molecules of importance for DNA-damage induced apoptotic signalling in NSCLC cell lines after irradiation with different radiation qualities i.e. low LET g-IR or accelerated nitrogen ions by comparing the phosphorylation status in these two cases. Briefly, a NSCLC-cell line which is resistant to low LET irradiation are treated with low and high LET irradiation, respectively. After cell lysis and tryptic digestion of proteins, the phoshorylated peptides are enriched using the OFFGEL isoelectric focusing instrument (Agilent Biotech) and TiO2 chromatography (Larsen et al 2005). The peptides are identified by mass spectrometry using LC-FT-ICR-MS/MS in collaboration with Prof. Roman Zubarev at Dept. of Biological and Medical Mass Spectrometry, Uppsala University. For validation and to examine if identified novel signalling molecules belong to already known signalling transduction pathways, we will use pharmacological inhibitors or siRNA towards known signal transducers such as ATM, DNA-PK, c-Abl, p53-family proteins or SAPK and investigate if the protein phosphorylation status and/or radiation response are changed .

Last updated: 2008-01-10