BACKGROUND: The critical role of PTEN in regulating the PI3K/Akt/mTOR signaling pathway raises the possibility that targeting downstream effectors of the PI3K pathway, such as Bcl-2, might be an effective anti-proliferative strategy for PTEN-deficient prostate cancer cells. METHODS: Four prostate cancer cell lines (LNCaP, PC3, DU145, 22Rv1) were assayed for their levels of total Akt and Ser473 phosphorylated Akt (p-Akt) by Western Blotting; their growth rates and sensitivity to different doses of paclitaxel were determined by cell counts after Trypan Blue dye exclusion assay. Cells were subjected to different combinations of starvation (growth factors and/or aminoacids withdrawal), paclitaxel treatment and Bcl-2 silencing by siRNA. Cell viability was evaluated by Trypan Blue dye exclusion assay, Propidium Iodide (PI) and Annexin-V/PI staining. RESULTS: We assessed the sensitivity of different prostate cancer cell lines to starvation and we observed a differential response correlated to the levels of Akt activation. The four prostate cancer cell lines also showed different sensitivity to taxol treatments; LNCaP and 22Rv1 cells were more resistant to paclitaxel than DU145 and PC3 cells. Combining taxol with growth factors and aminoacids deprivation leaded to a more than additive reduction of cell viability compared to single treatments in PTEN-mutant LNCaP cells. Down-modulation of anti-apoptotic Bcl-2 protein by siRNA sensitized LNCaP cells to taxanes and starvation induced cell death. CONCLUSIONS: Silencing Bcl-2 in PTEN-mutated prostate cancer cells enhances the apoptotic effects of combined starvation and taxol treatments, indicating that inhibition of Bcl-2 may be of significant value in PTEN-mutant tumor therapy.

Down-modulation of Bcl-2 sensitizes PTEN-mutated prostate cancer cells to starvation and taxanes / A. Calastretti, G. Gatti, C. Quaresmini, A. Bevilacqua. - In: THE PROSTATE. - ISSN 0270-4137. - 74:14(2014 Oct), pp. 1411-1422. [10.1002/pros.22857]

Down-modulation of Bcl-2 sensitizes PTEN-mutated prostate cancer cells to starvation and taxanes

A. Calastretti
Primo
;
G. Gatti
Secondo
;
A. Bevilacqua
2014

Abstract

BACKGROUND: The critical role of PTEN in regulating the PI3K/Akt/mTOR signaling pathway raises the possibility that targeting downstream effectors of the PI3K pathway, such as Bcl-2, might be an effective anti-proliferative strategy for PTEN-deficient prostate cancer cells. METHODS: Four prostate cancer cell lines (LNCaP, PC3, DU145, 22Rv1) were assayed for their levels of total Akt and Ser473 phosphorylated Akt (p-Akt) by Western Blotting; their growth rates and sensitivity to different doses of paclitaxel were determined by cell counts after Trypan Blue dye exclusion assay. Cells were subjected to different combinations of starvation (growth factors and/or aminoacids withdrawal), paclitaxel treatment and Bcl-2 silencing by siRNA. Cell viability was evaluated by Trypan Blue dye exclusion assay, Propidium Iodide (PI) and Annexin-V/PI staining. RESULTS: We assessed the sensitivity of different prostate cancer cell lines to starvation and we observed a differential response correlated to the levels of Akt activation. The four prostate cancer cell lines also showed different sensitivity to taxol treatments; LNCaP and 22Rv1 cells were more resistant to paclitaxel than DU145 and PC3 cells. Combining taxol with growth factors and aminoacids deprivation leaded to a more than additive reduction of cell viability compared to single treatments in PTEN-mutant LNCaP cells. Down-modulation of anti-apoptotic Bcl-2 protein by siRNA sensitized LNCaP cells to taxanes and starvation induced cell death. CONCLUSIONS: Silencing Bcl-2 in PTEN-mutated prostate cancer cells enhances the apoptotic effects of combined starvation and taxol treatments, indicating that inhibition of Bcl-2 may be of significant value in PTEN-mutant tumor therapy.
PTEN; Akt; nutrient starvation; taxanex; chemosensitization
Settore BIO/14 - Farmacologia
ott-2014
Article (author)
File in questo prodotto:
File Dimensione Formato  
pros22857.pdf

accesso riservato

Descrizione: articolo principale
Tipologia: Publisher's version/PDF
Dimensione 1.42 MB
Formato Adobe PDF
1.42 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/255216
Citazioni
  • ???jsp.display-item.citation.pmc??? 6
  • Scopus 18
  • ???jsp.display-item.citation.isi??? 12
social impact