Lipid mapping by desorption electrospray ionization mass spectrometry in a murine breast DMBA carcinogenesis model

- DESI-MSI was employed to generate lipid distribution maps of DMBA breast cancer model.
- First in vivo study of chemical carcinogenesis and analysis by DESI-MSI.
- Significant differences in lipid profiles of control and DMBA samples were detected.
- Most lipids were detected in greater abundance in the non-neoplastic cancer samples.
- Lipid ion of m/z 336 was observed only in the neoplastic areas.

Lipids are molecules with a large structural diversity inserted in various cytological and pathological processes, such as in breast cancer. The knowledge of the metabolic and lipid profiles in breast cancer helps to identify and classify neoplastic and non-neoplastic areas and aids therefore in precise histological diagnosis and in the identification of new promising therapeutic targets. The present study aimed to compare non-neoplastic samples of Sprague-Dawley rat breast lesions to a DMBA chemical carcinogenesis model via DESI-MS imaging. The model Sprague-Dawley rats were treated with the carcinogen compound DMBA, and frozen mammary samples with or without tumors were imaged. The developed ductal carcinomas showed indeed contrasting lipid relative abundances as compared to non-neoplastic breast tissue. Most lipids belong to the fatty acyl family, and were detected in greater abundance in the non-neoplastic cancer samples. The lipid ion of m/z 336 was observed only in the neoplastic areas. This is the first study that demonstrates changes in lipid profile of mammary tumors in rats treated with DMBA, and the promising results seems to encourage and serve as a guide for further lipidomic studies regarding breast cancer.

134