Impact of E6-associated protein on the proliferation and invasion of prostate cancer cells in bone metastasis.

Purpose: To understand E6 associated protein (E6-AP)'s influence on prostate cancer cell proliferation and infiltration, thus providing the theoretical basis for developing therapeutic drugs for prostate cancer metastasis to the bone.

Methods: Electroporation was performed to introduce linear regulatory plasmid PrevTet-off-in and conjugative plasmid PrevTRE2-flag-E6AP into prostate cancer cell line to establish wild-type E6-AP over-expressing transgenic LNCaP cell line; Western blot assay was adopted to examine expression levels of E6-AP, mammalian target of rapamycin (mTOR), protein kinase B (Akt), and phosphoinositide 3-kinase (PI3K); PI3K inhibitor LY294002 was applied to all the cells and MTT assay was used to measure cell proliferation; Matrigel invasion chamber assay was adopted to detect cancer cell migration and invasion.

Results: Stably transfected LNCaP cells that over expressed E6-AP had higher expression levels of PI3K, Akt, and mTOR than control LNCaP cells; MTT assay showed that E6-AP-LNCaP cells were more responsive to the inhibitory effect of LY294002; Matrigel invasion chamber assay revealed increased cell crawling and adhesiveness of E6-AP-LNCaP cells.