Metabolism study of breast cancer cells subjected to CLA using NMR

Author(s)

Roberta Manzano Maria

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT)
• Defense date: 2013-11-13

Examining board members

Luiz Alberto Colnago; Ana Carolina de Mattos Zeri

• Advisor: Luiz Alberto Colnago

Abstract

Conjugated linoleic acid (CLA), a group of isomers of linoleic acid,is found in milk and meat of ruminant animals, which have anticarcinogenic, antidiabetic, antiatherogenic and anthiadipogenic properties. In this thesis the effect of CLA (cis-9, trans-11) in two cell lines of breast cancer, MCF-7 and MDA-MB-231 was studied High Resolution Magic Angle Spinning (HR-MAS) NMR technique. HR-MAS was used to identify and quantify the metabolites of the two cells and was effective to observe significant changes in metabolites due to the addition of CLA to the culture medium. The breast cancer cells, MCF-7 subjected to 100 µM CLA had a significantly higher acetone signal. This pattern was not observed for MDA-MB-231. It was noted that the content of phosphocholine decreased in both cell lines treated with 100 µM CLA. Given these results and simulation with molecular modeling we are suggesting that CLA inhibits the enzyme HMG-CoA reductase (HMGR), similar to statins. By binding to HMGR, CLA prevents binding of the HMG-CoA (substrate), preventing their conversion to mevalonate, and consequently the cholesterol biosynthesis. The HMG-CoA is then converted to acetoacetate and then acetone. This mechanism explains the increase of acetone and decreased of phosphocholine, since there is mutual positive control with cholesterol and phospholipids. Therefore, the inhibition of HMGR by CLA may be the biochemical explanation for its anticarcinogenic activities as well as antidiabetic, antiatherogenic and antiadipogenic properties reported in the literature. It was also demonstrated the capability of Filter Diagonalization Method (FDM) to process time domain HR-MAS signals. FDM was able to obtain high-resolution spectra without the water suppression and T2 filter. (AU)

• FAPESP's process: 09/17846-4 - Metabolomic analysis in tumor cellular lineages treated with conjugated linoleic acid by Nuclear Magnetic Resonance
• Grantee: Roberta Manzano Maria
• Support Opportunities: Scholarships in Brazil - Doctorate