Identification of a subset of human non-small cell lung cancer patients with high PI3Kß and low PTEN expression, more prevalent in squamous cell carcinoma.

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 PI3Kß and its relation to PTEN in non-small cell lung cancer NSCLC remain unclear. EXPERIMENTAL DESIGN: Antibodies directed against PI3Kß 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 820 NSCLC patient samples analyzed in a separate laboratory applying the same validated antibodies and staining protocols. The staining intensities for PI3Kß and PTEN were explored and colocalization of these markers in individual tumor cores were correlated. RESULTS: PI3Kß 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 PI3Kß 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 PI3Kß accompanied by a reduction/loss of PTEN, for whom selective PI3Kß inhibitors may be predicted to achieve greater clinical benefit.

Genetically abnormal circulating cells in lung cancer patients: an antigen-independent fluorescence in situ hybridization-based case-control study.

PURPOSE: We performed a study to determine if a fluorescence in situ hybridization (FISH)-based assay using isolated peripheral blood mononuclear cells (PBMCs) with DNA probes targeting specific sites on chromosomes known to have abnormalities in non-small cell lung cancer (NSCLC) cases could detect circulating genetically abnormal cells (CACs). EXPERIMENTAL DESIGN: We evaluated 59 NSCLC cases with stage I through IV disease and 24 controls. PBMCs and matched tumors were hybridized with 2 two-color [3p22.1/CEP3 and 10q22.3 (SP-A)/CEP10) and 2 four-color [CEP3, CEP7, CEP17, and 9p21.3 (URO); and EGFR, c-MYC, 6p11-q11, and 5p15.2 (LAV)] FISH probes. Percentages of cytogenetically abnormal cells (CACs) in peripheral blood and in matched tumor specimens were quantified by using an automated fluorescent scanner. Numbers of CACs were calculated based on the percentage of CACs (defined as PBMCs with genetic abnormalities) per milliliter of blood and expressed per microliter of blood. RESULTS: Patients with NSCLC had significantly higher numbers of CACs than controls. Mean number of CACs ranged from 7.23 +/- 1.32/microL for deletions of 10q22.3/CEP10 to 45.52 +/- 7.49/microL for deletions of 3p22.1/CEP3. Numbers of CACs with deletions of 3p22.1, 10q22.3, and 9p21.3, and gains of URO, increased significantly from early to advanced stage of disease. CONCLUSIONS: We have developed a sensitive and quantitative antigen-independent FISH-based test for detecting CACs in peripheral blood of patients with NSCLC, which showed a significant correlation with the presence of cancer. If this pilot study can be validated in a larger study, CACs may have a role in the management of patients with NSCLC.

SAR and inhibitor complex structure determination of a novel class of potent and specific Aurora kinase inhibitors.

A novel series of 5-aminopyrimidinyl quinazolines has been developed from anilino-quinazoline 1, which was identified in a high throughput screen for Aurora A. Introduction of the pyrimidine ring and optimisation of the substituents both on this ring and at the C7 position of the quinazoline led to the discovery of compounds that are highly specific Aurora kinase inhibitors. Co-crystallisation of one of these inhibitors with a fragment of Aurora A shows the importance of the benzamido group in achieving selectivity.