TY - JOUR
T1 - Identification of a subset of human non-small cell lung cancer patients with high PI3Kβ and low PTEN expression, more prevalent in squamous cell carcinoma
AU - Cumberbatch, Marie
AU - Tang, Ximing
AU - Beran, Garry
AU - Eckersley, Sonia
AU - Wang, Xin
AU - Ellston, Rebecca P.A.
AU - Dearden, Simon
AU - Cosulich, Sabina
AU - Smith, Paul D.
AU - Behrens, Carmen
AU - Kim, Edward S.
AU - Su, Xinying
AU - Fan, Shuqiong
AU - Gray, Neil
AU - Blowers, David P.
AU - Wistuba, Ignacio I.
AU - Womack, Chris
PY - 2014
Y1 - 2014
N2 - Purpose: The phosphoinositide 3-kinase (PI3K) pathway is a major oncogenic signaling pathway and an attractive target for therapeutic intervention. Signaling through the PI3K pathway is moderated by the tumor suppressor PTEN, which is deficient or mutated in many human cancers. Molecular characterization of the PI3K signaling network has not been well defined in lung cancer; in particular, the role of PI3Kβ and its relation to PTEN in non-small cell lung cancer NSCLC remain unclear. Experimental Design: Antibodies directed against PI3Kβ and PTEN were validated and used to examine, by immunohistochemistry, expression in 240 NSCLC resection tissues [tissue microarray (TMA) set 1]. Preliminary observations were extended to an independent set of tissues (TMA set 2) comprising 820NSCLC patient samples analyzed in a separate laboratory applying the same validated antibodies and staining protocols. The staining intensities for PI3Kβ and PTEN were explored and colocalization of these markers in individual tumor cores were correlated. Results: PI3Kβ expression was elevated significantly in squamous cell carcinomas (SCC) compared with adenocarcinomas. In contrast, PTEN loss was greater in SCC than in adenocarcinoma. Detailed correlative analyses of individual patient samples revealed a significantly greater proportion of SCC in TMA set 1 with higher PI3Kβ and lower PTEN expression when compared with adenocarcinoma. These findings were reinforced following independent analyses of TMA set 2. Conclusions: We identify for the first time a subset of NSCLC more prevalent in SCC, with elevated expression of PI3Kβ accompanied by a reduction/loss of PTEN, for whom selective PI3Kβ inhibitors may be predicted to achieve greater clinical benefit.
AB - Purpose: The phosphoinositide 3-kinase (PI3K) pathway is a major oncogenic signaling pathway and an attractive target for therapeutic intervention. Signaling through the PI3K pathway is moderated by the tumor suppressor PTEN, which is deficient or mutated in many human cancers. Molecular characterization of the PI3K signaling network has not been well defined in lung cancer; in particular, the role of PI3Kβ and its relation to PTEN in non-small cell lung cancer NSCLC remain unclear. Experimental Design: Antibodies directed against PI3Kβ and PTEN were validated and used to examine, by immunohistochemistry, expression in 240 NSCLC resection tissues [tissue microarray (TMA) set 1]. Preliminary observations were extended to an independent set of tissues (TMA set 2) comprising 820NSCLC patient samples analyzed in a separate laboratory applying the same validated antibodies and staining protocols. The staining intensities for PI3Kβ and PTEN were explored and colocalization of these markers in individual tumor cores were correlated. Results: PI3Kβ expression was elevated significantly in squamous cell carcinomas (SCC) compared with adenocarcinomas. In contrast, PTEN loss was greater in SCC than in adenocarcinoma. Detailed correlative analyses of individual patient samples revealed a significantly greater proportion of SCC in TMA set 1 with higher PI3Kβ and lower PTEN expression when compared with adenocarcinoma. These findings were reinforced following independent analyses of TMA set 2. Conclusions: We identify for the first time a subset of NSCLC more prevalent in SCC, with elevated expression of PI3Kβ accompanied by a reduction/loss of PTEN, for whom selective PI3Kβ inhibitors may be predicted to achieve greater clinical benefit.
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U2 - 10.1158/1078-0432.CCR-13-1638
DO - 10.1158/1078-0432.CCR-13-1638
M3 - Article
C2 - 24284056
AN - SCOPUS:84893475587
SN - 1078-0432
VL - 20
SP - 595
EP - 603
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 3
ER -