Premium
Depletion of Protein Interacting with Never in Mitosis Gene A‐1 (PIN1) decreases mammary adenocarcinoma cell growth in culture, but increases VEGF and tumor growth in mice
Author(s) -
Schneider Ryan A,
Liu Tongzheng,
Huang Yongcheng,
Keshvara Lakhu,
Hoyt Dale G
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.321.8
Subject(s) - gene knockdown , biology , pin1 , carcinogenesis , cell growth , transfection , cancer research , peptidylprolyl isomerase , small hairpin rna , microbiology and biotechnology , mammary tumor , cell culture , gene , cancer , genetics , breast cancer , isomerase
Protein Interacting with Never in Mitosis Gene A‐1 (PIN1), a peptidyl‐proline isomerase, is overexpressed in some breast cancers and may promote tumorigenesis. Therefore, we hypothesized that depletion of PIN1 in EMT6 mammary adenocarcinoma cells would decrease their growth. A short hairpin RNA sequence targeting murine PIN1 or mutated control construct was cloned in pLKO.1, transfected into EMT6 cells, and stable cell lines were produced via puromycin selection. PIN1 levels were undetectable in knockdown cells via western blotting. Cells were seeded in 96‐well plates for 24–48H, and stained with crystal violet to measure in vitro proliferation. As expected, PIN1 knockdown decreased proliferation at 24 and 48H compared to control cells (p<0.05). The in vivo effect of PIN1 depletion was determined by transplanting these cells into the 4 th mammary fat pad of BALB/c mice. Unexpectedly, PIN1 knockdown increased tumor volume nearly 2‐fold compared to control by day 28 (p<0.05). Extraction and western blotting revealed a nearly 2‐fold increase in VEGF, normalized to protein, in the knockdown tumors compared to control. These results reveal a dichotomy between growth in culture and in vivo, and suggest that tumor PIN1 status regulates host factors or responsiveness to them. Furthermore, loss of PIN1 in malignant epithelial cells may stimulate angiogenesis and growth in a PIN1‐positive host environment.