Abstract
The growth of GH4C1, GH3, GH1, and GH3C15 rat pituitary tumor cell lines was studied in a serum-free medium (designated TRM-1) formulated with 1:1 (vol/vol) mixture of Ham's F12 nutrient mixture and Dulbecco's modified Eagle's medium (F12-DME) containing 15 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), 50 micrograms/ml gentamicin supplemented with 10 micrograms/ml bovine insulin, 10 micrograms/ml human transferrin (Tf), 10 ng/ml selenous acid, 10 nM 3,5,3'-triiodothyronine (T3), 50 microM ethanolamine (Etn), and 500 micrograms/ml bovine serum albumin. Of the lines evaluated, only the GH1 failed to grow in TRM-1. Passage of the GH4C1 and GH3 lines from serum-containing medium into TRM-1 caused an initial selection resulting in cells that grew progressively at higher rates and finally were maintained indefinitely in TRM-1. These populations showed a requirement for supraphysiologic concentrations of T3 (1.0 to 10 nM). After adaptation of the GH4C1 line in TRM-1 for greater than or equal to 20 generations, removal of components gave a less complex mixture containing 15 mM HEPES, 50 micrograms/ml gentamicin, 10 micrograms/ml Tf, 10 nM T3, and 50 microM Etn (designated TRM-2) that supported serial passage of the cells. Under these conditions, thyroid hormone dependence was lost progressively. When T3 was removed from TRM-2 adapted cells, a third population was selected that no longer required thyroid hormones and was only slightly stimulated by T3. These studies demonstrated that the combination of serum-containing and serum-free conditions can be used to select pituitary cell populations that a) required both serum-factor(s) and T3 for optimum growth, b) required supraphysiologic concentrations of T3 without serum proteins other than Tf and albumin, and c) were completely autonomous in that they proliferated in medium supplemented only with Tf and nutrients without necessity of other serum factor(s) or T3.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.