The complexity of cancer signaling networks limits the efficacy of most single agent treatments and brings about challenges in identifying effective combinatorial therapies. In this study, we used chronic active B cell receptor (BCR) signaling in diffuse large B cell lymphoma (DLBCL) as a model system to establish a computational framework to optimize combinatorial therapy in silico. We constructed a detailed kinetic model of the BCR signaling network, which captured the known complex crosstalk between the NFκB, ERK and AKT pathways and multiple feedback loops. Combining this signaling model with a data-derived tumor growth model, we predicted viability responses of many single drug and drug combinations in agreement with experimental data. Under this framework, we exhaustively predicted and ranked the efficacy and synergism of all possible combinatorial inhibitions of eleven currently targetable kinases in the BCR signaling network. Ultimately, our work establishes a detailed kinetic model of the core BCR signaling network and provides the means to explore the large space of possible drug combinations.
Major Findings
Using chronic active B cell receptor (BCR) signaling in diffuse large B cell lymphoma (DLBCL) as a model system, we developed a kinetic-modeling based computational framework for predicting effective combination therapy in silico. By integrative modeling of signal transduction, drug kinetics and tumor growth, we were able to directly predict drug-induced cell viability responses at various dosages, which were in agreement with published cell line experimental data. We implemented computational screening methods that identified potent and synergistic combinations in silico and validated our independent predictions in vitro.
Quick Guide to Equations and Assumptions
A kinetic model was constructed for the BCR signaling network according to the following rules. For protein-protein binding interactions, we assumed that this type of reaction were under equilibrium and solved the steady-state level of protein complex analytically in the model,
false[
AB
false]
=
1
(
1
+
K
(
[
T
A
]
+
[
T
B
]
)
)
-
false(
1
+
K
false(
false[
T
A
false]
+
false[
T
B
false]
false)
false)
2
-
4
K
2
[
T
A
]
[
T
B
]
2
K
where [TA] and [TB] stand for the total concentration of protein species A and B respectively, [AB] represents the concentration of the protein complex, K is the inverse of the dissociation constant Kd. For kinase catalyzed reactions, we adopted the classic Michaelis-Menten kinetics, j
1
d
P
d
t
=
1
k
cat
[
E
]
[
S
]
K
m
+
[
S
]
where
1dPdt is the rate of catalytic product formation, kcat is the turnover rate, Km is the Michaelis-Menten constant, [E] and [S] are concentration of enzyme and substrate respectively. Each interaction in the BCR signaling network was depicted by corresponding terms according to above rules. The full kinetic model consists of 28 state...