In addition, the activation of PLD by pervanadate triggered phosphorylation of tyrosine 705 residue on STAT-3, and its phosphorylation was dramatically higher in TPC-1 cells (from papillary carcinoma) that have an endogenous RET/PTC1 than in ARO cells (from anaplastic carcinoma) without alteration of total STAT-3 expression.
RET rearrangements are restricted to a well-differentiated papillary carcinoma, suggesting that RET/PTC positive papillary carcinomas do not progress to undifferentiated carcinoma.