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6th ESACP Congress, Heidelberg, April 7-11, 1999 |
A014
Raman spectroscopy is recognised as one of the most effective approaches
in pathology diagnosis. This technique has been used to differentiate between
sensitive and MDR-resistant cancer cells. Several cell lines including K562,
CEM, LR73 and MCF7 (MDR phenotype) and HL60 and J82 cells (non-MDR phenotype)
have been investigated. Spectral analysis of the sensitive and resistant cell
lines has allowed to identify the differences proper to the MDR and
non-MDR-phenotype. In the case of MDR phenotype, sensitive cells exhibit a
higher intensity than the resistant counterpart, in particular in the amide
I and III regions. This was not the case with non-MDR phenotype. Also, cells
exhibiting MDR-phenotype obtained both by drug selection and transfection
with mdr gene, are included. Data show that it can be possible to identify
the spectral characteristics associated with this resistance mechanism
(profile, percentage of proteins and lipids). Resolution enhancement methods
(deconvolution, derivatives, and curve fitting) have also been used to
evaluate the conformational changes in the secondary structure of cell
constituents that accompany the MDR phenotype. Surface-enhanced Raman
spectroscopy (SERS) has become a powerful and non-invasive probe for
investigating the molecular and cellular interaction of drugs with their
targets (DNA, receptors, and enzymes). The comparison in-vitro models allow
to elucidate the biological effect of the drugs. The development of new types
of SERS-active substrates has extended the applicability of this technique
to medical diagnosis. Two kinds of SERS active substrates, characterised as
"bio-compatible" systems, can be used for investigation on single living
cells: colloid suspensions and microelectrodes (point probes), and island
films (surface probes). This technique has been used as a rapid, effective
and reproducible method to investigate in-situ different cellular
compartments for a better localization of the drug inside the cell (free or
bound to its pharmacological target).
RAMAN SPECTROSCOPY OF VIABLE CELLS AND TISSUES
Manfait M, Sockalingum GD, Morjani H, Beljebbar A
Unité MEDIAN, IFR53, UFR de Pharmacie, Université de Reims Champagne-Ardenne,
France