Page 81 - D. Cancer biology

Secreted kinase Fam20C regulates extracellular phosphoproteome that
related to glioblastoma recurrence

Chan Il Kim , Jong-Bae Park 1
1
1 Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National
Cancer Center, Goyang-si, Gyeonggi-do, Korea
BACKGROUND AIM

Glioblastoma multiforme (GBM) is one of the most aggressive We postulate that during this progression free period,
primary brain tumors. Advancements in therapeutics during the
past decades have not significantly increased the overall GBM cells acquire drug resistance. The purpose of
survival of patients with this disease. Although recent this study is to find out which protein plays an
approaches slightly increased progression free survival, important role in acquiring this resistance.
recurrence of GBM seems to be inevitable and its therapeutics
outcome is highly case dependent.

METHODS

1. Cell culture: U87 cells were maintained in DMEM supplemented with 10% FBS (HyClone).
2. Orthotopic mouse model: U87 cells were transplanted following resuspension in DMEM. Cells were injected
streotactically in to left striatum of 5-week-old female BALB/c nude mice.
3. Proliferation assay: Cell titer-glo luminescent cell viability assay(Gibco, 100ml). By using 96 well plates, each
well was filled with 100 number of U87 cells and it incubated in room temperature with 1:1 ratio.
4. shRNA Knockdown: Knockdown of Fam20C using lentiviral-based shRNA in U87 cells was performed as
described (Tagliabracci et al., 2012).

RESULTS

Through the proteomic analysis in well- Figure 1 Figure 2
established avastin resistance mouse A A U87 shFAM20C
model, we identified that large number of 1WK 3WK 4WK 5WK 6WK Con A B C D
protein expression signatures are altered. Vehicle Nestin
Among those proteins, Family with U87
sequence similarity 20 member C FAM20C
(Fam20C) is overexpressed in recurrence Avastin Β-actin
tumor tissue induced by avastin. Fam20C B U87
is a kinase that phosphorylates S-x-E/pS B 1500 shCtrl
motif on proteins in the extracellular matrix, sh#A
sh#B
extracellular domain of membrane protein Cell Growth 1000 sh#C
sh#D
and other secreted protein. Fam20C 500
generates the majority of the extracellular Vehicle
Vehicle
Avastin
phosphorproteome. After Fam20C Avastin 0
overexpression, we confirmed that C 0 1 3 5
recurrence tumor grows rapidly (Figure 1). 0.8 Days in culture
Next, we generate Fam20C knockdown 0.6 C 1.0
U87 cell line using shRNAs. Effects of 0.4
0.2
Fam20C KD are reducing proliferation in Relative Protein Expression U87 Proteome Samples, FAM20C
vitro and increasing survival rate in avastin 0 Cumulative survival 0.5
treated group in vivo (Figure 2). -0.2 Vehicle
Avastin
shFAM20C
Combination
Avastin 10m/kg
Vehicle
0.0
0
20
40
Days 60 80
CONCLUSION REFERENCES ACKNOWLEDGEMENTS
Fam20C related downstream Tagliabracci VS, et al. (2012) Secreted We thank members of the JBP
signaling is still elusive. But we kinase phosphorylates extracellular laboratory for insightful discussions and
supposed Fam20C is related to proteins that regulate biomineralization. comments regarding the study.
stemness (Figure 2A). The results Science 336(6085):1150-1153.
allow Fam20C to be the novel Tagliabracci VS, et al. (2015) A single Contact information
target of the combinational therapy kinase generates the majority of the
for GBM patients with avastin secreted phosphoproteome. Cell 161: Chan Il Kim : cik@ncc.re.kr
resistance. 1619-1632. Jong Bae Park : jbp@ncc.re.kr