Preclinical evaluation of the PI3K-mTOR dual inhibitor PF-04691502 as a novel therapeutic drug in nasopharyngeal carcinoma
Nasopharyngeal carcinoma (NPC) is common in Southeast Asia and over 40 % of NPC tissues have PIK3CA amplification. This study characterized the preclinical activity of a novel potent dual PI3K/mTOR inhibitor, PF-04691502, in five NPC cell lines: CNE-1, HK1, CNE-2, HONE-1 and C666-1, in which all of the cell lines possessed basal and activated expression of Akt and p70S6K. Over 80 % inhibition of cell growth in all of these cell lines were achieved after 72 h of PF-04691502 incubation and their IC50 were in hundred nanomolar range. CNE-2, HK1 and HONE-1 were selected to further evaluate the effect of PF-04691502 on cell cycle, apoptosis and Akt downstream signaling. PF-04691502 induced G0/G1 cell cycle arrest and apoptosis at 24 h incubation and it significantly abrogated Akt and its downstream signaling by suppressing the expression of p-mTOR, p-p70S6K, p-Akt(S473, T308), p-S6 and p-4E-BP1, suggesting its effectiveness in inhibition of translation and protein synthesis. Anti-proliferation was also observed in 3D culture system and spheroids formation of NPC cell line HONE-1-EBV was strongly inhibited by PF-04691502. Antitumor activity was observed in CNE-2 xenograft in 2 weeks of 10 mg/kg PF-09641502 treatment to tumor bearing athymic nude mice. Both tumor volume and weight in treatment group were significantly lower than those in vehicle group while no obvious body weight decrease was found, suggesting this working dose was effective and well-tolerated. Additive effects were observed in combination of PF-09641502 with either cisplatin or paclitaxel. There were no synergistic effect observed in drug combination but PF-09641502 alone was effective in treating cisplatin resistant cell lines as compared to its parental control. The beneficial effects of PF-09641502 in both in vitro and in vivo studies for NPC warrant a further investigation.
KeywordsNasopharyngeal carcinoma PI3K-mTOR dual inhibitor PF-04691502 Akt
This work is supported by an independent research grant from Pfizer. The authors would like to thank The Charlie Lee Charitable Foundation for the generous support of this study.
Conflict of interest
The authors declare that they have no conflict of interest in this study.
- 2.Chen J, Hu CF, Hou JH, Shao Q, Yan LX, Zhu XF, Zeng YX, Shao JY (2010) Epstein-Barr virus encoded latent membrane protein 1 regulates mTOR signaling pathway genes which predict poor prognosis of nasopharyngeal carcinoma. J Transl Med 8:30. doi: 10.1186/1479-5876-8-30 PubMedCentralCrossRefPubMedGoogle Scholar
- 3.Loong HH, Ma BB, Chan AT (2008) Update on the management and therapeutic monitoring of advanced nasopharyngeal cancer. Hematol Oncol Clin North Am 22(6):1267–1278, x. doi: 10.1016/j.hoc.2008.08.012
- 7.Yuan J, Mehta PP, Yin MJ, Sun S, Zou A, Chen J, Rafidi K, Feng Z, Nickel J, Engebretsen J, Hallin J, Blasina A, Zhang E, Nguyen L, Sun M, Vogt PK, McHarg A, Cheng H, Christensen JG, Kan JL, Bagrodia S (2011) PF-04691502, a potent and selective oral inhibitor of PI3K and mTOR kinases with antitumor activity. Mol Cancer Ther 10(11):2189–2199. doi: 10.1158/1535-7163.MCT-11-0185 CrossRefPubMedGoogle Scholar
- 8.Herzog A, Bian Y, Vander Broek R, Hall B, Coupar J, Cheng H, Sowers A, Cook J, Mitchell JB, Chen Z, Kulkarni A, Van Waes C (2013) PI3K-mTOR inhibitor PF-04691502 anti-tumor activity is enhanced with induction of wild-type TP53 in human xenograft and murine knockout models of head and neck cancer. Clin Cancer Res. doi: 10.1158/1078-0432.CCR-12-2716 PubMedCentralPubMedGoogle Scholar
- 9.Kinross KM, Brown DV, Kleinschmidt M, Jackson S, Christensen J, Cullinane C, Hicks RJ, Johnstone RW, McArthur GA (2011) In vivo activity of combined PI3K/mTOR and MEK inhibition in a Kras(G12D);Pten deletion mouse model of ovarian cancer. Mol Cancer Ther 10(8):1440–1449. doi: 10.1158/1535-7163.MCT-11-0240 CrossRefPubMedGoogle Scholar
- 10.Wander SA, Zhao D, Besser AH, Hong F, Wei J, Ince TA, Milikowski C, Bishopric NH, Minn AJ, Creighton CJ, Slingerland JM (2013) PI3K/mTOR inhibition can impair tumor invasion and metastasis in vivo despite a lack of antiproliferative action in vitro: implications for targeted therapy. Breast Cancer Res Treat 138(2):369–381. doi: 10.1007/s10549-012-2389-6 PubMedCentralCrossRefPubMedGoogle Scholar
- 12.Simmons BH, Lee JH, Lalwani K, Giddabasappa A, Snider BA, Wong A, Lappin PB, Eswaraka J, Kan JL, Christensen JG, Shojaei F (2012) Combination of a MEK inhibitor at sub-MTD with a PI3K/mTOR inhibitor significantly suppresses growth of lung adenocarcinoma tumors in Kras(G12D-LSL) mice. Cancer Chemother Pharmacol 70(2):213–220. doi: 10.1007/s00280-012-1899-6 CrossRefPubMedGoogle Scholar
- 13.Britten C, Adjei A, Millham R, Houk B, Wainberg Z, Guthrie T, Dy G, LoRusso P (2010) First-in-human study of PF-04691502, a small-molecule, oral, dual inhibitor of PI3K and mTOR in patients with advanced cancer: preliminary report on safety and pharmacokinetics. Paper presented at the EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics, Berlin, Germany, November 16–19, 2010Google Scholar
- 16.Ma BB, Lui VW, Poon FF, Wong SC, To KF, Wong E, Chen H, Lo KW, Tao Q, Chan AT, Ng MH, Cheng SH (2010) Preclinical activity of gefitinib in non-keratinizing nasopharyngeal carcinoma cell lines and biomarkers of response. Invest New Drugs 28(3):326–333. doi: 10.1007/s10637-009-9316-7 PubMedCentralCrossRefPubMedGoogle Scholar
- 17.O’Reilly KE, Rojo F, She QB, Solit D, Mills GB, Smith D, Lane H, Hofmann F, Hicklin DJ, Ludwig DL, Baselga J, Rosen N (2006) mTOR inhibition induces upstream receptor tyrosine kinase signaling and activates Akt. Cancer Res 66(3):1500–1508. doi: 10.1158/0008-5472.CAN-05-2925 PubMedCentralCrossRefPubMedGoogle Scholar
- 18.Ma BLV, Ho K, Lau CPY, Ng M, Cheng SH, Tsang CM, Tsao SW, Shi M, Hui EP, Chan ATC (2010) Preclinical evaluation of the dual PI3K-mTOR inhibitor BEZ235 in nasopharyngeal carcinoma cell lines. In Proc Am Assoc Cancer Res Meeting, Chicago Abstract 1638Google Scholar
- 19.Wallin JJ, Guan J, Prior WW, Lee LB, Berry L, Belmont LD, Koeppen H, Belvin M, Friedman LS, Sampath D (2012) GDC-0941, a novel class I selective PI3K inhibitor, enhances the efficacy of docetaxel in human breast cancer models by increasing cell death in vitro and in vivo. Clin Cancer Res 18(14):3901–3911. doi: 10.1158/1078-0432.CCR-11-2088 CrossRefPubMedGoogle Scholar