Tri-n-butyltin chloride promotes morphological transformation and induces proliferin expression in C3H10T1/2 cells

Transcripts from the murine gene family proliferin, which are increased by a wide assortment of chemical promoters of C3H10T1/2 cell morphological transformation, were shown to be induced by tri-n-butyltin chloride at concentrations above 50 nM. Two-stage transformation assays, with 3-methylcholanthrene as inducer and tri-n-butyltin chloride as promoter, were performed to determine if promotion of morphological transformation and proliferin induction were properties shared by this compound. Tri-n-butyltin chloride synergistically enhanced focus formation at concentrations ranging from 20 to 75 nM. Di-n-butyltin dichloride, n-butyltin trichloride and tin (II) chloride, but not tin (IV) chloride, were also effective inducers of proliferin. Changes in patterns of TPA-inducible, secreted proteins, including those likely to be proliferin, were detected following organotin treatment of confluent monolayers. Tri-n-butyltin chloride resembles other agents active as promoters in C3H10T1/2 two-stage transformation assays by possessing an ability to induce proliferin expression.