Our data demonstrate that quantification of plasma DNA is an accurate technique amenable to standardization, which might complement current methods for the prediction of patient survival. This approach might be considered for evaluation in large prospective studies.

Purpose: The recognition of a number of leukemiaspecific cytogenetic abnormalities and their role as independent prognostic factors have provided considerable insights into leukemia pathogenesis and have paved the way to adopt risk-adapted treatment. However, f 50% of newly diagnosed acute myeloid leukemia (AML) have a normal karyotype. There has therefore been much interest in identifying molecular markers that could help to improve the prognostic stratification of patients with normal-karyotype AML.Experimental Design: Consecutive untreated AML patients (n = 67) from a single institution all with normal karyotype were analyzed for the presence of mutations in the myeloid transcription factor gene CEBPA (for CCAAT/ enhancer binding protein-A), for internal tandem duplications (ITD) of the tyrosine kinase receptor gene FLT3 (for fms-like tyrosine kinase 3), and for expression of the BAALC gene (for brain and acute leukemia, cytoplasmic).Results: 17.9% of normal-karyotype AML had mutations in the CEBPA gene, and 28.4% had FLT3-ITD; 65.7% (44 of 67) had high BAALC expression and 34.3% (23 of 67) had low BAALC expression. Patients with CEBPA mutations had a very favorable course of their disease. Median diseasefree survival (DFS) and overall survival (OS) were 33.5 and 45.5 months, respectively, compared with 10 (e.g., 12 months in patients without CEBPA mutations; P = 0.0017; P = 0.0007). AML patients with FLT3-ITD had significantly shorter median DFS (P = 0.0328) and OS (P = 0.0148) than patients without FLT3-ITD. High BAALC expression predicted for a shorter DFS (P = 0.0152) and OS (P = 0.0210) compared with AML with low BAALC expression; 53.7% of normal-karyotype AML had neither FLT3-ITD nor CEBPA mutations. We found that high BAALC expression in normalkaryotype AML with neither FLT3-ITD nor CEBPA mutations (18 of 67) indicates adverse prognosis for both DFS and OS (P = 0.0001; e.g., P = 0.0001) compared with the group with low BAALC expression and absent FLT3-ITD and CEBPA mutations (18 of 67). Thus, BAALC expression represents a novel prognostic marker particularly for normal-karyotype AML patients with neither FLT3-ITD nor CEBPA mutations.Conclusions: Assessment of CEBPA mutations, FLT3-ITD, and BAALC expression permits to split normalkaryotype AML into clinically distinct subgroups.

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Using a panel of cDNA microarrays comprising 47 650 transcript elements, we have carried out a dual-channel analysis of gene expression in 39 resected primary human non-small cell lung tumours versus normal lung tissue. Whilst *11 000 elements were scored as differentially expressed at least twofold in at least one sample, 96 transcripts were scored as over-represented fourfold or more in at least seven out of 39 tumours and 30 sequences 16-fold in at least two out of 39 tumours, including 24 transcripts in common. Transcripts (178) were found under-represented fourfold in at least seven out of 39 tumours, 31 of which are underrepresented 16-fold in at least two out of 39 lesions. The relative expression levels of representative genes from these lists were analysed by comparative multiplex RT -PCR and found to be broadly consistent with the microarray data. Two dramatically over-represented genes, previously designated as potential tumour suppressors in breast (maspin) and lung and breast (S100A2) cancers, were analysed more extensively and demonstrate the effectiveness of this approach in identifying potential lung cancer diagnostic or therapeutic targets. Whilst it has been reported that S100A2 is downregulated in NSCLC at an early stage, our microarray, cmRT -PCR, Western and immunohistochemistry data indicate that it is strongly expressed in the majority of tumours.

Aurora kinases are key regulators of chromosome segregation during mitosis. We have previously shown by microarray analysis of primary lung carcinomas and matched normal tissue that AURKB (22 out of 37) and AURKA (15 out of 37) transcripts are frequently over-represented in these tumours. We now confirm these observations in a second series of 44 carcinomas and also show that aurora B kinase protein levels are raised in the tumours compared to normal tissue. Elevated levels of expression in tumours are not a consequence of high-level amplification of the AURKB gene. Using a coding sequence polymorphism we show that in most cases (seven out of nine) tumour expression is predominantly driven from one AURKB allele. Given the function of aurora B kinase, we examined whether there was an association between expression levels and genetic instability. We defined two groups of high and low AURKB expression. Using a panel of 10 microsatellite markers, we found that the group showing the higher level of expression had a higher frequency of allelic imbalance (P=0.0012). Analysis of a number of other genes that are strongly and specifically expressed in tumour over normal lung, including SERPINB5, TERT and PRAME, showed marked allelic expression imbalances in the tumour tissue in the context of balanced or only marginally imbalanced relative allelic copy numbers. Our data support a model of early carcinogenesis wherein defects in the process of inactivation of lung stem-cell associated genes during differentiation, contributes to the development of carcinogenesis.