1. DETERMINATION OF LECITHIN-CHOLESTEROL ACYLTRANSFERASE (LCAT) AND
CHOLESTEROL-ESTER TRANSFER PROTEIN (CETP) ACTIVITY IN PATIENTS WITH COLORECTAL
CANCER
Marija Petrović, Jovana Jovanović, Tamara Gojković, Sandra Vladimirov, Vesna Spasojević-Kalimanovska, Aleksandra
Zeljković, Jelena Vekić, Zorana Jelić-Ivanović
Department of Medical Biochemistry, Faculty of Pharmacy, University of Belgrade
Background: Lecithin-cholesterol acyltransferase (LCAT) is a
plasma enzyme that performs the esterification of free
cholesterol to cholesterol esters while cholesterol ester transfer
protein (CETP) enables the exchange of cholesterol esters and
triglycerides between HDL and triglyceride-rich lipoproteins in
rerverse transport of cholesterol.
Aim: The objective of this work was to examine the activity of
LCAT and CETP in human plasma in patients with colorectal
cancer and compare it with the control group.
Material and methods:The study included 30 healthy
people (KG) and 79 patients that have been diagnosed
with colorectal cancer (CRC). LCAT activity is obtained by
mathematical calculation of the difference between free
(FC) and esterified cholesterol (EC) concentration before
and after a 2-hour incubation of the samples at 37°C,
while the CETP-mediated transfer of cholesterol esters
was measured as the difference between the rate of
decrease in FC in the whole plasma and the rate of EC
increase in HDL during 2 hours of incubation at 37 °C.
Concentrations of FC and EC were determined by
colorimetric method with automatic analyzer ILAB 300+.Results:
Table 1. Biochemical parameters and LCAT and CETP activity in CG and CRC patients
˚ Data are presented as
mean ± standard deviation
˚˚ Data are presented as the
geometric mean (95%
confidence interval)
˚˚˚ Data are shown as
median (interquartile range)
Conclusion: The results of this study showed that there were significant differences in the activities of LCAT and CETP
between the KG and patients with CRC, which could indicate the activity disturbance of these enzyme and the consequent
disruption in the process of reverse cholesterol transport in patients with CRC.
KG CRC p
Age˚(years) 58,8±5,7 65,6±10,4 p<0,01
BMI˚(kg/m2) 27,2±5,3 25,4±3,8 p<0,05
TC˚(mmol/l) 6,09±1,14 4,58±1,37 p<0,05
HDL˚(mmol/l) 1,25±0,30 1,21±0,41 p=0,65
LDL˚(mmol/l) 2,40±0,60 2,24±0,81 p=0,33
TG˚˚(mmol/l) 1,41 (0,08-0,22) 1,20 (0,03-0,12) p=0,09
CETP˚˚˚ (µmol/l/h) -10,17 (-33,17-54,58) 39,29 (-14,19-74,31) p<0,05
LCAT˚˚˚(µmol/l/h) 100,5 (70,62-125,76) 67,0 (44,33-92,67) p>0,05
Figure 1 - CETP activity in CG and CRC
patients
Figure 2 – LCAT activity in CG and CRC
patients
LCAT
correlations
Total
cholesterol
LDL
ρ 0,276 0,236
p 0,021 0,05
Table 2 – Correlation between
LCAT and CETP activity and
lipid parameters
p≤ 0,05
p> 0,05
CETP
correlations
HDL
ρ -0,446
p <0,05