E-TABM-1215 - Transcription profiling of MDA-MB-231 mammary cancer cells conditionally expressing progesterone receptor isoforms PRA and PRB
Released on 11 June 2012, last updated on 2 May 2014
The progesterone receptor isoforms PRA and PRB are implicated in breast cancer development and metastasis. Expression ratio PRA/PRB is imbalanced in such cancers under the influence of MAPK-dependent extracellular stimuli that strongly impact progesterone-responsive transcriptional regulation. In order to determine the isoform-specific regulated genes in a metastatic cancer cell, we established the iPRAB cell line derived from MDA-MB-231 mammary cancer cells (ER-, PR-). This cell line conditionally expressed PRA and/or PRB under the control of RSL1 and doxycycline (Dox) non-steroid ligands, respectively, in a dose-dependent manner. The bi-inducible expression system was generated using a combination of the Rheoswitch (NE Biolabs) and T-Rex (Invitrogen) vector systems as described in the article. We investigated the transcriptomes obtained in cells treated by either RSL1 (for PRA), or Dox (for PRB), or RSL1 + Dox (for PRA + PRB) for 24 h and then by either 10 nM progesterone (+) or vehicle (-) for 6 h. Control experiments were obtained from cells grown in the absence of RSL1, doxycycline and in the presence of progesterone (O+) or vehicle (O-). Experimental conditions of PRA/PRB expression ratio were ranged from 0.1 to 10, and the maximum expression of a given isoform was set to 300 fmol per mg proteins following 24 h induction. After removing redundant probes and pseudogens, the processed data identified 1014 distinct regulated genes subdivised in 3 classes : genes responding either only to unliganded PR isoforms (-), or only to liganded (+) or to both conditions (mixed ±). Each classe was subdivided according to isoform specificity criteria (A, B, AB, A&B, A&AB, B&AB, A&B&AB) leading to define 3X7 clusters of genes per classe. Each subset was then further analyzed by complete hierarchical clustering through up or down-regulation criteria. These data indicated that PR target genes selectivity is highly dependent of PRA/PRB expression ratio as well as ligand status and highlight the major impact of PR on transcriptional regulation of genes involved in breast cancer and metastasis.
transcription profiling by array, compound treatment
Differential regulation of breast cancer-associated genes by progesterone receptor isoforms PRA and PRB in a new bi-inducible breast cancer cell line. Khan JA, Bellance C, Guiochon-Mantel A, Lombès M, Loosfelt H. :e45993 (2012), PMID:23029355
Differential regulation of breast cancer associated genes by progesterone receptor isoform A and B in a new bi-inducible breast cancer cell line. Khan J.A., Bellance C., Guiochon-Mantel A., Lombès M., Loosfelt H.