Messenger RNA expression of transporter and ion channel genes in undifferentiated and differentiated Caco-2 cells compared to human intestines.
OBJECTIVE
The purpose of this work was to study the influence of cell differentiation on the mRNA expression of transporters and channels in Caco-2 cells and to assess Caco-2 cells as a model for carrier-mediated drug transport in the intestines.


METHODS
Gene mRNA expression was measured using a custom-designed microarray chip with 750 deoxyoligonucleotide probes (70mers). Each oligomer was printed four times on poly-lysine-coated glass slides. Expression profiles were expressed as ratio values between fluorescence intensities of Cy3 and Cy5 dye-labeled cDNA derived from poly(A) + RNA samples of Caco-2 cells and total RNA of human intestines.


RESULTS
Significant differences in the mRNA expression profile of transporters and channels were observed upon differentiation of Caco-2 cells from 5 days to 2 weeks in culture, including changes for MAT8, S-protein, and Nramp2. Comparing Caco-2 cells of different passage number revealed few changes in mRNAs except for GLUT3, which was down-regulated 2.4-fold within 13 passage numbers. Caco-2 cells had a similar expression profile when either cultured in flasks or on filters but differed more strongly from human small and large intestine, regardless of the differentiation state of Caco-2 cells. Expression of several genes highly transcribed in small or large intestines differed fourfold or more in Caco-2 cells.


CONCLUSIONS
Although Caco-2 cells have proven a suitable model for studying carrier-mediated transport in human intestines, the expression of specific transporter and ion channel genes may differ substantially.
Anderle
Pascale
P
Department of Biopharmaceutical Sciences, School of Pharmacy, University of San Francisco, San Francisco, California, USA. Pascale.Anderle@isrec.unil.ch
Rakhmanova
Vera
V
Woodford
Katie
K
Zerangue
Noa
N
Sadée
Wolfgang
W
D000328:Adult; D000368:Aged; D018938:Caco-2 Cells / Q000166:cytology* / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000166:cytology; D007473:Ion Channels / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D026901:Membrane Transport Proteins / Q000096:biosynthesis* / Q000235:genetics; D008875:Middle Aged; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics
D007473:Ion Channels; D026901:Membrane Transport Proteins; D012333:RNA, Messenger