Uptake of Tritiated Thymidine, Deoxyglucose and Methionine in Three Lung Cancer Cell Lines: Deoxyglucose Uptake Mirrors Tritiated Thymidine Uptake

Abstract

[¹⁸F]-fluorodeoxyglucose and [¹¹C]-methionine are tracers which are widely used in oncological positron emission tomography. This study has been designed to assess the deoxyglucose and methionine uptake behaviour in three cell lines from different lung cancer histotypes. Tracer uptake was compared with proliferative activity as determined by growth curves and tritiated thymidine uptake. Deoxyglucose paralleled thymidine in all cell lines, peaking in the lag phase, decreasing throughout the exponential phase, and reaching its minimum in the plateau phase. The correlation was statistically verified and Spearman’s ρ ranged from 0.79 to 0.99. The absolute methionine uptake was always highest and always peaked on day 2, followed by a quite rapid decrease. However, besides the delay in maximum uptake, methionine incorporation was also related to proliferation, although the statistical correlations were weaker. These results show for the first time a clear correlation between deoxyglucose uptake and cell proliferation in a model comparing tracer uptake in different growth phases. Although delayed, methionine uptake was also related to cell growth and its greater intensity could be of interest for clinical use.

l-Carnitine induces recovery of liver lipid metabolism in cancer cachexia

“…It is tempting to speculate that the higher liver incorporation of L-carnitine could represent a compensatory mechanism to offset the decreased absorptive capacity of the small intestine and the possible reduction of endogenous biosynthesis. Indeed, tumour cells are known to avidly uptake methionine (Nerini-Molteni et al 2000), which is the precursor of L-carnitine, thereby possibly decreasing the host's L-carnitine synthesis capacity. Therefore, tumour growth may mimic the fasting state when the supply of L-carnitine and its precursors is diminished and L-carnitine incorporation by the perfused rat liver is enhanced (Luci et al 2008).…”

Feasibility of optimizing the dose distribution in lung tumors using fluorine‐18‐fluorodeoxyglucose positron emission tomography and single photon emission computed tomography guided dose prescriptions

“…The rationale for a non uniform dose component proportional to activity is based on studies showing that the FDG-PET standardized uptake value correlates to tumor cell proliferation rate. [25][26][27][28][29][30][31][32][33][34][35] This yields the growth rate equation…”

“…13,15,[20][21][22][23][24] Most relevant to the present work, several studies have established the correlation between FDG uptake and tumor proliferation rate. [25][26][27][28][29][30][31][32][33][34][35] This seems to suggest that FDG uptake correlates to tumor aggressiveness. Consequently, it also appears to suggest that the spatial distribution of FDG uptake correlates to the spatial distribution of tumor aggressiveness.…”

Potential pitfalls of radiolabel adsorption to ceramic biomaterials

“…Metabolic labeling of DNA or protein in cultured cells with radioactive, low molecular weight precursors is a popular technique used widely for the in vitro analysis of macromolecule biosynthesis. In particular, the detection of incorporated tritiated thymidine ([ 3 H]‐thy) as a measure of DNA synthesis, and thus proliferation of cultured cells, has been used for many years 1, 2. Moreover, cellular incorporation of selected radiolabeled amino acids (e.g., leucine or methionine) into newly synthesised protein has been shown to correlate with an increase in protein synthesis and/or cell number 3–5.…”