Project description:Ablation of ERRalpha significantly delays ERBB2-induced mammary tumorigenesis and ERRalpha regulates genes of the ERBB2 amplicon. To further investigate the relationship between ERRalpha activity and RTK signaling, we mapped ERRalpha binding sites in SKBr3 cells upon EGF treatment or heregulin treatment. Inhibition of ERBB2 signaling using the RTK inhibitor lapatinib impacts on ERRalpha stability, while cells resistant to lapatinib treatment exhibit restored ERRalpha expression. We therefore mapped ERRalpha binding sites in parental (sensitive) cells (pSKBr3) as well as in lapatinib-resistant cells (LRSKBr3). ChIP-Seq analysis of ERRalpha binding profile in SKBr3 or BT-474 breast cancer cells.
Project description:These studies are aimed at understanding gene expression chnages in a Her2 positive breast cancer cell line that has developed acquired resistance to lapatinib. Samples include SKBR3 parental and resistant (SKBR3-R) under basal conditions and in response to 0.1 and 1uM lapatinib treatment after 24 hours.
Project description:Ablation of ERRalpha significantly delays ERBB2-induced mammary tumorigenesis and ERRalpha regulates genes of the ERBB2 amplicon. To further investigate the relationship between ERRalpha activity and RTK signaling, we depleted ERRalpha in SKBr3 cells upon serum starvation, EGF treatment or heregulin treatment. Inhibition of ERBB2 signaling using the RTK inhibitor lapatinib impacts on ERRalpha stability. Since we have shown that the development of lapatinib-resistance restaures the expression of ERRalpha in breast cancer cells, we performed depletion of ERRalpha in SKBr3 cells that have developped resistance to lapatinib treatment in order to identify a potential reprogramming of ERRa transcriptional activity associated to lapatinib resistance, For the study of growth factor effec on ERRalpha activity, total RNA was obtained from human SKBr3 breast cancer cells cultured in DMEM deprived of FBS (starved) for 24 hours and treated with PBS, EGF (100uM) or Heregulin (100uM) for an additional 24h. Cells were transfected with siRNA against ERRalpha or with siControl for 60 hours prior to harvesting. For the effect of ERRalpha in lapatinib resistance cells, parental SKBr3 cells (pSKBr3) and Lapatinib-resistant cells (LRSKBr3, maintained in 2uM lapatinib) were transfected with siControl (siC) or siERRalpha for 60 hours prior to harvesting and RNA extraction
Project description:Ablation of ERRalpha significantly delays ERBB2-induced mammary tumorigenesis and ERRalpha regulates genes of the ERBB2 amplicon. To further investigate the relationship between ERRalpha activity and RTK signaling, we mapped ERRalpha binding sites in SKBr3 cells upon EGF treatment or heregulin treatment. Inhibition of ERBB2 signaling using the RTK inhibitor lapatinib impacts on ERRalpha stability, while cells resistant to lapatinib treatment exhibit restored ERRalpha expression. We therefore mapped ERRalpha binding sites in parental (sensitive) cells (pSKBr3) as well as in lapatinib-resistant cells (LRSKBr3).
Project description:In SKBR3 cells, simultaneous targeting of RARM-kM-1 with all-trans retinoic acid (ATRA) and HER2 with lapatinib results in synergistic anti-tumor responses. SKBR3 cells were treated with vehicle (DMSO), lapatinib (100 nM), ATRA (100 nM) or lapatinib+ATRA for 36 hours and miRNA expression profile was determined by one-color Agilent microarray experiments.
Project description:SKBR-3 or BT474m1 HER2+ breast cancer cells were treated with either DMSO, 300nM lapatinib, 300nM JQ1, or lapatinib and JQ1 in combination for 48h.
Project description:Ablation of ERRalpha significantly delays ERBB2-induced mammary tumorigenesis and ERRalpha regulates genes of the ERBB2 amplicon. To further investigate the relationship between ERRalpha activity and RTK signaling, we depleted ERRalpha in SKBr3 cells upon serum starvation, EGF treatment or heregulin treatment. Inhibition of ERBB2 signaling using the RTK inhibitor lapatinib impacts on ERRalpha stability. Since we have shown that the development of lapatinib-resistance restaures the expression of ERRalpha in breast cancer cells, we performed depletion of ERRalpha in SKBr3 cells that have developped resistance to lapatinib treatment in order to identify a potential reprogramming of ERRa transcriptional activity associated to lapatinib resistance,
Project description:We compared untreated HCC1419 cells with Lapatinib resistant HCC1419 cells that were either treated with Lapatinib for only 9 days before harvesting (drug tolerant persisters, DTPs) or were growing in the presence of Lapatinib (>70 days) (drug tolerant expanded persisters, DTEPs). We show that the Notch pathway is significantly over-expressed in DTEPs when compared to untreated cells.
