Gene expression profiling of Lentivirus-mediated Gene Silencing of RARβ Inhibits A549 Non-Small Cell Lung Cancer stem cells

Retinoic acid Receptor Beta (RARβ) protein encoded by RARβ gene is a nuclear receptor protein that binds to retinoic acid (RA) to mediate RA function in cellular signalling in embryogenic morphogenesis, cell growth and differentiation. However, the function of RARβ in cancer stem cells (CSCs) maintenance of non-small cell lung cancer (NSCLC) is yet to be determined We used microarrays to analyse the trancriptomic changes in lung cancer and cancer stem cells following RARβ silencing. Lentivirus-mediated RARβ downregulation using ShRNA was performed in A549 cells, A549 putative CSCs (CD166+EpCAM+ and CD166+CD44+) and putative non-CSCs (CD166-EpCAM- and CD166-CD44-). Total RNA was extracted and hybridize on Affymetrix microarrays. We sought to obtain homogeneous populations of embryos at each developmental stage in order to increase the temporal resolution of expression profiles. To that end, we hand-selected embryos according to morphological criteria at five time-points: before pole cell formation, i.e. before zygotic transcription (T0), during the slow phase (T1) and the fast phase (T2) of cellularisation and at the beginning (T3) and the end (T4) of gastrulation.