All human lung cancer cell lines were cultured under standard conditions (37C in 5% CO2 atmosphere) and grown in RPMI (Gibco?, Invitrogen Corp, Grand Island, NY) supplemented with 10% FBS. GUID:?4BE1D99D-8789-481E-B5F5-A2E68ABEB1FD Table S7: Viability data for NVP-BEZ235 and Erlotinib in H2170 and HCC2935 cancer cell lines. (XLS) pone.0031331.s008.xls (20K) GUID:?F22AE3E1-D86D-4E2E-9F21-16CC0CE961C3 Abstract Introduction We assessed expression of p85 and p110 PI3K subunits in non-small cell lung cancer (NSCLC) specimens and the association with mTOR expression, and studied effects of targeting the PI3K/AKT/mTOR pathway in NSCLC cell lines. Methods Using Automated Quantitative Analysis we quantified expression of PI3K subunits in two cohorts of 190 and 168 NSCLC specimens and correlated it with mTOR expression. We studied effects of two PI3K inhibitors, LY294002 and NVP-BKM120, alone and in combination with rapamycin in 6 NSCLC cell lines. We assessed activity of a dual PI3K/mTOR inhibitor, NVP-BEZ235 alone and with an EGFR inhibitor. Results p85 and p110 tend to be co-expressed (p<0.001); p85 expression was higher in adenocarcinomas than squamous cell carcinomas. High p85 expression was associated with advanced stage and poor survival. Agnuside p110 expression correlated with mTOR (?=?0.276). In six NSCLC cell lines, addition of rapamycin to LY294002 or NVP-BKM120 was synergistic. Even very low rapamycin concentrations (1 nM) resulted in sensitization to PI3K inhibitors. NVP-BEZ235 was highly active in NSCLC cell lines with IC50s in the nanomolar range and resultant down-regulation of pAKT and pP70S6K. Adding Erlotinib to NVP-BEZ235 resulted in synergistic growth inhibition. Conclusions The association between PI3K expression, advanced stage and survival in NSCLC suggests that it might be a valuable drug target. Concurrent inhibition of PI3K and mTOR is usually synergistic are relatively infrequent in lung cancer, copy number gain has been reported in 33.1% of squamous cell lung cancer and in 6.2% adeno lung cancer in one large series [23]. PI3K signaling has been shown to mediate bronchioalveolar stem cell growth initiated by oncogenic in a mouse model of NSCLC [25]. Overexpression of p85 and p110 has been demonstrated to correlate with poor differentiation of primary lung cancers in a cohort that included 73 cases of NSCLC [26]. Our group has previously studied the expression of mTOR in NSCLC cohorts and found an association with improved outcome [27]. Inhibition of PI3K/AKT/mTOR signaling through pharmacologic and genetic approaches induces antiproliferative effects on certain NSCLC cell lines [17]C[21] and in lung cancer mouse models [25], [28]. A number of PI3K inhibitors are available for preclinical research. Older compounds like LY294002 or wortmannin have anti-tumor activity in preclinical models, but their poor solubility, narrow therapeutic index and crossover inhibition of other kinases have limited their clinical application. Newer PI3K inhibitors have entered early phase clinical trials, and activity of these agents should be assessed in diseases requiring new approaches, such as NSCLC. The purpose of our study was to characterize the expression of p85 and p110 subunits of Class IA PI3K in two large independents cohorts of NSCLC specimens and to assess the association with clinical and pathological variables including previously published mTOR expression. To obtain more precise, objective expression measures, we used a newly developed method of automated, quantitative analysis (AQUA) of tissue microarrays [29]. As redundant activators of the PI3K/AKT signaling pathway and unfavorable feedback loops [5] limit the efficacy of single agent therapies, our next purpose was to study the effects of targeting the PI3K/AKT signaling pathway at multiple levels in NSCLC cell lines. We found that higher expression of p85 correlated with poor survival and advanced stage. Expression of p110 correlated with that of mTOR. Concurrent inhibition of PI3K and mTOR resulted in synergistic growth suppression. Adding EGFR inhibition further enhanced the growth-inhibitory effects of a dual PI3K/mTOR inhibitor. Materials and Methods Tissue Microarray (TMA) Construction A NSCLC cohort was obtained from the H. Lee Moffitt Cancer Center (Tampa, FL). The Moffitt Cancer Center cohort (MTMA) contains cores from primary NSCLC tumors of patients diagnosed between 1991 and 2001. Follow-up time ranged between 0.8 months and 146.4 months, mean follow-up time of 52.3 months. Age at diagnosis ranged from 40.8 to 84.4 (mean age 69 years). The cohort included 54.5% males and 45.5% females. The Yale University cohort Rabbit Polyclonal to TEAD1 (YTMA) was constructed from paraffin-embedded, formalin-fixed tissue blocks obtained from the Yale University Department of Pathology Archives. The specimens were Agnuside resected between 1995 and 2003, with a follow-up range between 0.1 months and 182.25 months, and a mean follow-up time of 41 months. Age at diagnosis ranged from 21 to 90 (mean age 65 years). The cohort included Agnuside 51% males.