Question

31. FGF receptor 1 (FGFR1) belongs to a family of tyrosine kinase receptors often amplified in lung cancer.  H520 cell line was stimulated by bFGF (20 ng/ml) for 20 min, with or without the pretreatment of AZD4547 (1 μM) for 40min. Then the cells were collected and analyzed by Western blot (figure A).  H520 cells were also stimulated with bEGF (20 ng/ml) and protein levels were analyzed after 1, 6, 12, and 24 hours after bEGF treatment (Figure B).  Lastly, mRNA levels of Gli2 protein targets were examined upon treatment with bEGF (figure C).

H520 P-FGFR FGFR1 P-ERK L-AKT AZD4547 bFGF H520 oh 1h 6h 12h bFGF (20 ngml) GLID 24h GL2| P-ERK B-tubulin H520 Control FGF Relative mRNA level of GLIZ target genes BCLZ GLI HHIP PTCHI

p – phosphorylated

t – total

A. What do you think ADT4547 is?

It is an inhibitor.

B. What protein(s) are downstream from FGFR?

C. Which Gli2 target gene is most responsive to bFGF treatment?

Answer 1

A. ADT4547 is tyrosine kinase inhibitor.The proteins are are activated by adding a phosphate group to the protein , a step that tyrosine kinase inhibits.these inhibitors are typically used as anticancer drugs.they are also called tryphostins.These inhibitors operate by 4 different mechanisms : they can compete with ATP, the phosphorylation entity,or both or both can act in a allosteric fashion, namely bind to site outside the active site, affecting its activity by conformational change.

B. downstream has shown to regulate several distinct MAP kinases including ERK1/2, JNK and p38.

C. The bFGF activates the fibroblast growth factor receptor and tumor growth factor receptor beta signalling determines migratory and invasive capabalities of tumor cells. HHIP is most responsive .