Effects of a-Retinoic Acid on Proliferation of Cat and Rat Thyroid Cell Lines in Vitro

Boesinger J., Gerber H., Peter H.J., et al.

Annales d’endocrinologie, 1991. 52(1): p.59.

 

Retinoids control cellular differentiation and proliferation; however, the effect appears to be extremely different depending on the tissue.  There are only very few recent studies on the effects of retinoids on thyroid follicular cells in vitro (van Herle et al, JCEM 71:  755, 1990).  For this reason we have investigated the growth effect of alpha-retinoic acid (RA) on proliferation of 6 thyroid cell lines from cats and rats. Five cell lines (PETCAT 1-4, ROMCAT), established from toxic adenomatous cat goiters (Gerber et al, 10th ITC, The Hague, 1991, Abstract 120), and the rat cell line FRTL-5 were grown as monolayers in 24 well plates for 8d without or with alpha-retinoic acid (RA) in concentrations of 0.05 uM, 0.5 uM and 5uM.  The medium used was Coon’s modified Ham F12 supplemented with 1% (for FRTL-5 5%) calf serum and 6 hormones.  Proliferation was measured by DNA determination. The effect of 0.05, 0.5 and 5 uM RA on proliferation of the cell lines (expressed as ug DNA/well) (mean +/- SD; n = 4) is shown in the following Table:

RA (uM) PETCAT 1 PETCAT 2 PETCAT 3 PETCAT 4 ROMCAT FRTL 5

0 3.1 +/- 0.2 18.2 +/- 0.2 9.3 +/- 0.6 6.6 +/- 3.0 11.1 +/- 0.6 4.2 +/- 0.24

0.05 3.0 +/- 0.2 17.1 +/- 0.3 6.8 +/- 0.4 8.0 +/- 0.2 13.0 +/- 0.4 2.7 +/- 0.06

0.50 1.0 +/- 0.5 14.9 +/- 0.3 5.1 +/- 0.5 4.5 +/- 0.2 11.5 +/- 0.9 1.2 +/- 0.11

5.00 1.4 +/- 0.2 16.3 +/- 0.4 5.5 +/- 0.5 3.7 +/- 0.5 8.6 +/- 1.4 0.9 +/- 0.02

In conclusion, RA has no effect on one cat cell line (PETCAT 2) and a very poor effect on ROMCAT, but reduces proliferation of the three other feline cell lines by 55%, 41% and 44% (PETCAT 1, 3 and 4) at the highest dose.  By far the most prominent inhibition occurs in FRTL-5 cells.  Thus, not only thyroid cells from different species but even different cells from thyroids affected by the same disease respond very differently to RA.