Ornithine decarboxylase activity is associated with proliferation but not with T₃‐induced differentiation of Caco‐2 cells

Abstract

Ornithine decarboxylase (ODC) activity and polyamine (putrescine, spermidine, spermine) concentrations were measured in parallel in enterocyte-like Caco-2 cells maintained under various culture conditions. ODC activity was maximal at the beginning of the exponential growth phase, decreasing dramatically thereafter to a negligible level at confluency (day 9). Kinetic studies performed on day 3 revealed the presence of a single enzyme with a Km around 200 microM and a Vmax of about 2 nmol CO2 released/h/mg protein. Similar values were obtained in both serum-supplemented and transferrin/selenium (TS)-defined culture media, indicating that ODC kinetic parameters are not affected by any factors present in serum. Polyamine concentrations were maximal on day 5. By day 9, they returned to initial levels and remained at these fairly high values until day 21. Since we have previously shown (Jumarie and Malo, 1994, in Vitro Cell. Dev. Biol., 30A:753-760) that triiodothyronine (T3) stimulates differentiation but not proliferation of Caco-2 cells maintained in TS-defined medium, we investigated if it induces differentiation by a polyamine-dependent mechanism. Short- and long-term measurements revealed similar ODC activity and polyamine levels whether T3 was present or not in the culture medium. These results clearly demonstrate that polyamine synthesis is more likely to be associated with Caco-2 cell proliferation, and that the T3 effect on Caco-2 cell differentiation does not involve polyamine biosynthesis. Moreover, our data show that ODC activity is not solely regulated by intracellular polyamine concentration.

Channelling of arginine in NO and polyamine pathways in colonocytes and consequences

“…Addition of putrescine or spermidine in the culture medium in addition to ODC inhibitor reverses almost totally the anti-proliferative effect of ODC inhibition (60)(61)(62)(63) indicating that exogenous putrescine and/or spermidine through entry into adenocarcinoma cells can substitute for endogenous production. Endogenous production of polyamines in Caco-2 cells appears to be more closely associated with cell proliferation than with cell differentiation (64). Using isolated nuclei from the human colon carcinoma cell line COLO 320, it has been shown that spermidine can increase the transcription of growth-associated genes (65).…”

Measurement of ornithine decarboxylase activity in cell extracts using mass spectrometry detection of dansylated putrescine

“…ODC activity in Caco-2 cells [14,15], in human colon adenocarcinoma [16] and in ascites hepatoma cells [17] was previously reported to be maximal at the beginning of the exponential growth phase, decreasing dramatically thereafter to a negligible level at conXuency.…”

Differential gene expression of chemokines in KRAS and BRAF mutated colorectal cell lines: Role of cytokines

“…The cell lines used in this study have similar characteristics to some cells of the crypt-villus axis. Caco2 cells were previously described to possess characteristics of normal small intestinal epithelium (Jumarie and Malo 1995), HT-29 and DLD1 cells are known to possess the characteristics of surface villus cells (Panja et al 1998).…”