Prostate cancer has one of the highest incidence rates of all cancers in Australia. A significant proportion of prostate cancers are indolent and this has resulted in many men with indolent disease being unnecessarily treated. This is a major unmet need in the treatment of prostate cancer and thus new biomarkers that accurately predict outcomes are required.
EVs, from a panel of 13 prostate cell lines, were investigated by Affymetrix Human Transcriptome arrays (HTA 2.0). This enabled the identification of nucleic acids that had different abundance in EVs from cells of metastastic origin compared to localised tumour, normal prostate cells or benign prostatic hyperplasia. EVs were collected from cell culture media devoid of supplements after 48 hours, by ultraconcentration. RNA was extracted and evaluated using a total RNA Agilent 2100 bioanalyzer chip. Validation of transcript abundances was performed by qRT-PCR. Resulting in the identification of a 5-gene panel that was able to discriminate between the EVs from the different parent cell types. Interestingly 3 transcripts all from the same family were identified to be significantly reduced in the metastatic EVs. Further these transcripts are known to be involved in drug resistance and apoptosis protection and therefore in addition to being potential biomarkers may also be directly involved in the metastatic process and present a therapeutic target.