Exploring the involvement of NOX4 in hypoxia adaptation of papillary thyroid cancer

Hypoxic stress is a feature of rapidly growing thyroid tumors. Cancer progression is thought to be driven by reactive oxygen species (ROS) induced hypoxia adaptation. NADPH oxidases (NOXs), which produce ROS as their primary and sole function, has become of particular interest in thyroid malignancy. NOX4 was demonstrated to be upregulated in papillary thyroid cancers, functioning as a mitochondrial energetic sensor to modulate ATP levels, mediating overproduction of ROS induced by IL-d, inversely correlating to thyroid differentiation. In this study, we analyzed hypoxia-treated BCPAP cells transfected with siRNA against NOX4. Results provides insight into the role of NOX4 in hypoxia adaptation. Overall design: BCPAP cells were transfected with scrambled siRNA or siRNA against NOX4. Subsequently the siRNA-transfected cells were cultured within 1% oxygen incubator. Three independent transfections were performed cells with control siRNA and for cells with siRNA specific to NOX4 where each transfection constitutes biological replicate. Knock-down of NOX4 in all samples was confirmed by quantitative real-time PCR.