Figure 1
From: CpG island shore methylation regulates caveolin-1 expression in breast cancer
Cav1 is upregulated and has an oncogenic role in fulvestrant-resistant breast cancer cell lines. (a) Cav1 expression in a panel of antiestrogen-sensitive and -resistant breast cancer cell lines as measured by quantitative reverse transcription–PCR analysis and relative to its expression level in MCF7 cells (mean±s.e., n=3). **P<0.01. Molecular features of these lines are given: ER, estrogen receptor; PR, progesterone receptor; Ba, basal-like; Lu, luminal. (b) Immunofluorescence staining of Cav1 in MCF7, MCF7-T and MCF7-F cells. Cells were serum/E2 starved for 3 days, following by fluorescence microscopy (magnification × 60 oil immersion objective. Bar, 15 μM). (c) Effect of tamoxifen and fulvestrant on endogenous Cav1 expression. MCF7 were serum/E2 starved for 3 days and then treated with 1 μM 4-hydroxitamoxifen (OHT) or 100 nM fulvestrant for 8 days. Cav1 expression was detected at the indicated time point by reverse transcription–PCR, relative to it in dimethyl sulfoxide (DMSO)-treated cells (mean±s.e., n=3). **P<0.01. (d) Fulvestrant sensitivity of Cav1-overexpressing MCF7 cells. Cells were transfected with pCMV6-XL5 (vector) or Cav1 overexpression plasmid (pCAV1) and then treated with the indicated doses of fulvestrant for 7 days. Cell viability was determined by MTT assay (absorbance at 600 nm linearly correlated with cell number; mean±s.e., n=6). The difference between vector-transfected cells and pCAV1-transfected cells was measured by Student’s t-test. *P<0.05. (e) Knockdown of Cav1 inhibits growth of MCF7-F cells. Cells were transfected with 50 nM control small interfering RNA (siCTR), or small interfering RNAs that target Cav1 (siCav1 and siPool) and cultured for 6 days. Cell viability was determined by MTT assay (mean±s.e., n=6). **P<0.01. (f) Knockdown of Cav1 inhibits clonogenicity of MCF7-F cells. Small interfering RNA-transfected cells were cultured in growth medium for 2 weeks and colonies containing >50 cells were scored (mean±s.e., n=3). **P<0.01. (g) Migration/invasion activity of MCF7-F cells (mean±s.e., n=3). **P<0.01.
