Background: The aim of this study was to characterize cell-free mRNA in malignant effusions and evaluate its correlation with the sensitivity of primary tumor cells to cisplatin and 5-fluorouracil (5-FU).
Patients and methods: Malignant effusions were collected from 43 patients and ERCC1 and TS mRNA transcripts in both the supernatants and tumor cells were characterized by real-time quantitative PCR. The sensitivity of primary tumor cells to cisplatin and 5-FU was analyzed using an ATP-TCA assay.
Results: Cell-free ERCC1 and TS mRNA transcripts were observed in 42 out of 43 specimens, with variable levels comparing gene expression patterns in paired-tumor cells (p < 0.0001, p = 0.02, respectively). TS mRNA levels in the supernatants were inversely correlated with the in vitro sensitivity of cancer cells to 5-FU in the gastrointestinal group (p = 0.002).
Conclusion: The cell-free mRNA transcripts in malignant effusions were highly detectable and cell-free TS mRNA in gastrointestinal cancer patients were strongly associated with the sensitivity of primary cancer cells to 5-FU in vitro.