Caco-2 cells resistance

Figure 21 Linearized double reciprocal plot of the effective permeability coefficients and corresponding stirring rates to determine the power dependency of the stirring rate and mass transfer resistances for the aqueous boundary layers and the Caco-2 cell monolayer in the Transwell system. 

The Caco-2 cell line was isolated from a human colon carcinoma, and has been characterized as one of the best in vitro models of intestinal epithelium. Indeed, in contrast to other intestinal cell lines, Caco-2 cells are able to constitute a homogenous monolayer and to spontaneously differentiate into polarized cells, highly similar to human mature enterocytes, after approximately 2 weeks of culture. Furthermore, the Caco-2 cells present microvillosities at the apical side and have a high transmembrane resistivity, which confirms the fact that the cells are confluent and link to one another via gap junctions. Finally, they can absorb different compounds, express many enzymes involved in intestinal metabolic pathways (Pinto et al. 1983, Musto et al. 1995, Salvini et al. 2002), and give reproducible in vitro results consistent with results obtained in in vivo studies (Artursson and Karlsson 1991). 

Y., Function and expression of multidrug resistance-associated protein family in human colon adenocarcinoma cells (Caco-2),... 

MDCK Madin-Darby canine kidney (MDCK) cells have received attention as an alternative to Caco-2 cells for permeability measurements. When grown under standard culture conditions, MDCK cells develop tight junctions and form monolayers of polarized cells. The main advantage over Caco-2 cells is the shorter culture time to confluence (3-5 days). The transep-ithelial electrical resistance of MDCK cells is lower than that of Caco-2 cells and thus, closer to the TEER of the small intestine in vivo. The permeability coefficients of hydrophilic compounds are usually lower in Caco-2 cells than in MDCK cells, which is consistent with the lower TEER values for MDCK cell monolayers. The nonhuman (canine) and nonintestinal (renal) origin of MDCK cells is considered as a disadvantage. They have low expression levels of transporter proteins and low metabolic activity [34], MDCK cells that are stably transfected with P-gp/MDRl are often proposed as an alternative for Caco-2 cells to study bidirectional transport of compounds and, more... 

H.M. Prime-Chapman, R.A. Fearn, A.E. Cooper, V. Moore, and B.H. Hirst. Differential multidrug resistance-associated protein 1 through 6 isoform expression and function in human intestinal epithelial Caco-2 cells. J Pharmacol Exp Ther. 311 476 184 (2004). 

Lo Y-L (2003) Relationships between the hydrophilic-lipophilic balance values of pharmaceutical excipients and their multidrug resistance modulating effect in Caco-2 cells and rat intestines. J Control Release 90 37 -8... 

Cell monolayers grown on permeable culture inserts form confluent mono-layers with barrier properties and can be used for drug absorption experiments. The most well-known cell line for the in vitro determination of intestinal drug permeability is the human colon adenocarcinoma Caco-2 [20, 21], The utility of the Caco-2 cell line is due to its spontaneous differentiation to enterocytes under conventional cell culture conditions upon reaching confluency on a porous membrane to resemble the intestinal epithelium. This cell model displays small intestinal carriers, brush borders, villous cell model, tight junctions, and high resistance [22], Caco-2 cells express active transport systems, brush border enzymes, and phase I and II enzymes [22-24], Permeability models... 

Other cell lines used in permeability studies include the T84 human colonic adenocarcinoma colonic crypt cell model. This line has a reduced carrier expression, secrets mucus, and has very high resistance [31, 32], The IEC cell line is a rat fetal intestinal epithelium cell with higher permeabilities than Caco-2 cells [33], LLC PKi is a pig kidney epithelial cell line with low expression of efflux systems, but expression systems for transport proteins [32], 2/4/A1 cells are a conditionally immortalized rat fetal intestinal epithelium line with crypt cell-like morphology and temperature-sensitive differentiation [34], They form differentiated monolayers with tight junctions, increased brush border enzymes when grown on extracellular matrices with laminin. Transport of drugs with LP in 2/4/A1 monolayers was comparable to that in the human jejunum and up to 300 times faster than that in Caco-2 monolayers. In contrast, the permeability of HP drugs was comparable in both cell lines [34],... 

Hirohashi, T., Suzuki, H., Chu, X.-Y., Tamai, I., Tsuji, A., and Sugiyama, Y., Function and expression of multidrug resistance-associated protein family in human colon adenocarcinoma cells (Caco-2), /. Pharmacol. Exp. Ther., 292, 265, 2000. 

Scaglione-Sewell B, Abraham C, Bissonnette M, Skarosi SF, Hart J, Davidson NO, Wali RK, Davis BH, Sitrin M, Brasitus TA (1998) Decreased FKC alpha expression increases cellular proliferation, decreases differentiation, and enhances the transformed phenotype of CaCo-2 cells. Cancer Res 58 1074-1081 Scala S, Dickstein B, Regis J, Szallasi Z, Blumberg PM, Bates SE (1995) Bryostatin 1 affects P-glycoprotein phosphorylation but not function in multidrug-resistant human breast cancer cells. Clinical Cancer Res 1 15851-1587 Scanlon, KJ, Kashani-Sabet M, Tone T, Funato T (1991) Cisplatin resistance in human acancers. Pharmac Ther 52 385-406... 

Walgren, R.A., Karnaky, K.J., Jr., Lindenmayer, G.E., and Walle, T., Efflux of dietary flavonoid quercetin 4 -(3-glucoside across human intestinal Caco-2 cell monolayers by apical multidrug resistance-associated protein-2, J. Pharmacol Exp. Ther., 294, 830, 2000. 

Xia CQ, Liu N, Yang D, et al. Expression, localization, and functional characteristics of breast cancer resistance protein in Caco-2 cells. Drug Metab Dispos 2005 ... 

Although there is a widespread perception that wild-type MDCK cells contain insignificant levels of P-gp to affect substrate transport, it has been demonstrated that this is not the case. It was shown that the transport of vinblastine sulfate across MDCK monolayers was indeed apically polarized (203). These results were duplicated by Hirst et al. using the same test compound, verapamil, in two different strains of MDCK cells. The transport profiles of verapamil showed polarity in both a high-resistance strain [TEER 2000 Q-cm2 and a low-resistance strain (TEER < 200 Q-cm2] (365). Recently, parallel studies were performed measuring the transport of a novel peptide, K02, across both MDCK and Caco-2 cells (364). The results showed nearly identical profiles for the AP to BL and BL to AP transport of this agent in both cell types. Although it is unlikely that all P-gp substrates will behave identically in both cell lines, these studies indicate that there is sufficient P-gp expression in MDCK cells to affect transport studies. Thus, MDCK cells can be used to evaluate the transport of compounds that are suspected to be substrates of P-gp. 

Bock KW, Eckle T, Ouzzine M, et al. Coordinate induction of antioxidants by UDP-glucuronosyltransferase UGT1A6 and the apical conjugate export pump MRP2 (multidrug resistance protein 2) in Caco-2 cells. Biochem Pharmacol 2000 59 467 170. 

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