Genomic Profiles Associated with Early Micrometastasis in Lung Cancer: Relevance of 4q Deletion

• Published in: Clinical cancer research 2009-03, Vol.15 (5), p.1566-1574
• Main Authors: WRAGE, Michaela, RUOSAARI, Salla, GLATZEL, Markus, YLSTRA, Bauke, PANTEL, Klaus, WIKMAN, Harriet, EIJK, Paul P, KAIFI, Jussuf T, HOLLMEN, Jaakko, YEKEBAS, Emre F, IZBICKI, Jakob R, BRAKENHOFF, Ruud H, STREICHERT, Thomas, RIETHDORF, Sabine
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - genetics; Adenocarcinoma - secondary; Adult; Aged; Aged, 80 and over; Antineoplastic agents; Biological and medical sciences; Brain Neoplasms - genetics; Brain Neoplasms - secondary; Carcinoma, Large Cell - genetics; Carcinoma, Large Cell - secondary; Carcinoma, Squamous Cell - genetics; Carcinoma, Squamous Cell - secondary; CGH; Chromosome Deletion; Chromosomes, Human, Pair 4 - genetics; Comparative Genomic Hybridization; Female; Gene Dosage; Gene Expression Profiling; Genome, Human; Humans; In Situ Hybridization, Fluorescence; lung cancer; Lung Neoplasms - genetics; Lung Neoplasms - pathology; Lymphatic Metastasis; Male; Medical sciences; microarray; micrometastasis; Middle Aged; Oligonucleotide Array Sequence Analysis; Pharmacology. Drug treatments; Pneumology; Small Cell Lung Carcinoma - genetics; Small Cell Lung Carcinoma - secondary; Tumors of the respiratory system and mediastinum
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.CCR-08-2188

Purpose: Bone marrow is a common homing organ for early disseminated tumor cells (DTC) and their presence can predict the subsequent occurrence of overt metastasis and survival in lung cancer. It is still unclear whether the shedding of DTC from the primary tumor is a random process or a selective release driven by a specific genomic pattern. Experimental Design: DTCs were identified in bone marrow from lung cancer patients by an immunocytochemical cytokeratin assay. Genomic aberrations and expression profiles of the respective primary tumors were assessed by microarrays and fluorescence in situ hybridization analyses. The most significant results were validated on an independent set of primary lung tumors and brain metastases. Results: Combination of DNA copy number profiles (array comparative genomic hybridization) with gene expression profiles identified five chromosomal regions differentiating bone marrow-negative from bone marrow-positive patients (4q12-q32, 10p12-p11, 10q21-q22, 17q21, and 20q11-q13). Copy number changes of 4q12-q32 were the most prominent finding, containing the highest number of differentially expressed genes irrespective of chromosomal size ( P = 0.018). Fluorescence in situ hybridization analyses on further primary lung tumor samples confirmed the association between loss of 4q and bone marrow-positive status. In bone marrow-positive patients, 4q was frequently lost (37% versus 7%), whereas gains could be commonly found among bone marrow-negative patients (7% versus 17%). The same loss was also found to be common in brain metastases from both small and non-small cell lung cancer patients (39%). Conclusions: Thus, our data indicate, for the first time, that early hematogenous dissemination of tumor cells might be driven by a specific pattern of genomic changes.