RT Journal Article SR Electronic T1 Detection of Specific mRNAs in Culture Medium Conditioned by Human Tumour Cells: Potential for New Class of Cancer Biomarkers in Serum JF Cancer Genomics - Proteomics JO Cancer Genomics Proteomics FD International Institute of Anticancer Research SP 43 OP 52 VO 2 IS 1 A1 LORRAINE O'DRISCOLL A1 ELAINE KENNY A1 MAIDER PEREZ DE VILLARREAL A1 MARTIN CLYNES YR 2005 UL http://cgp.iiarjournals.org/content/2/1/43.abstract AB Background: This study aimed to develop and optimise procedures to enable us to establish, in a well-controlled environment, if cancer cells routinely secrete gene transcripts potentially suitable for monitoring as biomarkers. Materials and Methods: Aliquots of the conditioned media (CM) exposed to cancer cells (including breast, lung and nasal cancer cell lines) were removed at intervals of 24 hours over a 96-hour time period and were passed through 0.45 μm or 0.22 μm filters, to remove cellular material. Methods for subsequent RNA extraction (from CM and cells) were investigated. RT-PCR was performed for a number of mRNAs, including mdr-1, mrp-1, CK-19, HnRNP B1, GST-π, topoisomerase II, bcl-2 and β-actin. Results: Gene transcripts, amplifiable by RT-PCR, were detected in conditioned media from all human cancer cell lines studied. This RNA did not result from the presence of cells in the conditioned media and, as expected, was absent from control medium not exposed to tumour cells. Conclusion: The results from this study indicate that gene transcripts may be secreted from human cancer cells and are detectable in the subsequent cell-free media. The methods developed and optimised here may be suitable for analysis of mRNAs as biomarkers in serum/plasma from cancer patients.