Thyroid Hormones Maintain The CTCL Malignant Phenotype Through Membrane- and Nuclear-Initiated Transcriptional Programs

CAYROL FLORENCIA; FERNANDO THARU; DIAZ FLAQUE MARIA CELESTE; FARIAS RICARDO; CREMASCHI GRACIELA; CERCHIETTI LEANDRO

New Orleans

Congreso; American Society of Hematology Annual meeting; 2013

Cutaneous T-cell lymphomas (CTCL) are a heterogeneous group of T-cell non-Hodgkin lymphomas (T-NHL) derived from skin-homing mature T cells. Thyroid hormones (THs) are crucial regulators of cellular differentiation, growth and metabolism. We recently found that THs stimulate the proliferation and metabolism of T cells and that this pathway is co-opted by T-NHL cells to maintain their malignant phenotype. Accordingly, a decrease in TH levels affects the proliferation of T-NHL cells. We also found that THs modulate these functions by activating both canonical nuclear (TR) and membrane receptors (mTR, that for most cells is represented by integrin vβ3). We now hypothesized that the characterization of the relative contribution of these receptors to the malignant phenotype of T-NHLs will allow for a more precise therapeutic intervention. The study presented here was conducted to determine (i) whether THs are pro-survival factors in CTCL and (ii) the relative contribution of TR and mTR to the effect of THs in CTCLs. To test this hypothesis, we first analyzed the expression of TR and mTR in CTLC cells (HuT 78, MJ and HuT102) vs. normal T cells (from peripheral blood) by qRT-PCR and immunoblotting. We found that CTCL expressed 2 to 10 fold more THRA, ITGAV and ITGB3 mRNA and protein than their normal counterpart (p