dΨ
dt
¼
∂Ψ
∂_ξ
df
dξ_
dt
þ
∂Ψ
∂df
ξ_
ddðÞf
dt
ð 30 Þ
Taking tumor growth rateξ_ constant as in [38] and taking
fractal dimensiondfas a control parameter, Eq. (30) can be rewrit-
ten as
dΨ
dt
¼
∂Ψ
∂df
ξ_
ddðÞf
dt
, ð 31 Þ
In previous work [49] we obtained the analytical solution of the
Gompertz equation for LNCaP tumor cell line (seeEq. ( 23)).
Substituting Eq. (23) into Eq. (29) it can be verified that
∂Ψ
∂df
ξÄn
<ξ_ξ
Än
0, and asddðÞdtf 0[49] we have
dΨ
dt
0 ð 32 Þ
This shows that the dissipation functionΨ is a Lyapunov
function of the control parameterdf.
4 Complexity of Cancer Glycolysis
In the last years, cancer glycolysis has been a target in oncology
research [78]. Most of tumor cells show a high glycolytic rate
compared with normal cells. This phenomenon is known in the
literature as Warburg’s effect and is observed without an increase in
the tricarboxylic acid cycle (TAC) or the electron transport chain
(ETC) rate [84]. The significant increase in glycolysis rate observed
in tumors has been recently verified, yet few oncologists or cancer
Fig. 6Relationship between metabolic rateqGl, fractal dimensiondf, and tumor growth rateξ. Reprinted from
[22]
Parameters Estimation in Phase-Space Landscape Reconstruction of Cell Fate... 145