microRNA epxression patterns can discriminate between patients with oligometastatic and polymetastatic progression: cell lines

Cancer staging and treatment frequently assume a binary division of tumors into localized or metastatic cancers. We proposed a state of metastatic disease defined by the number of metastases termed oligometastases. Patients with oligometastatic disease may be cured with localized methods of cancer treatment. We analyzed miRNA expression from paraffin blocks of primary or metastatic tumor samples derived from oligometastatic (? 5 metastases) patients treated with high dose localized radiotherapy. We report patterns of miRNA expression in the metastatic and primary tumor samples that identify patients who failed to progress to widespread polymetastases. We created a model of oligometastases of human tumors in immune compromised mice. The miRNA patterns of gene expression derived from patients accurately identified oligometastatic patterns in the mouse model as compared to animals that developed widespread metastases. MiRNA signatures may identify patients most likely to benefit from aggressive curative treatment of limited metastatic disease. Injection of MDA-MB-435-GFP cancer cells into the mammary fat pad of female athymic mice to develop spontaneous macroscopic lung metastasis. Tail vein experimental lung colonization assay was performed to model the development of MDA-MB-435-GFP Oligo- or Poly-metastases in the lung in vivo. Cell lines: Total RNA were derived from MDA-MB-435-L1-GFP (Ol-like) or MDA-MB-435-L1Mic (Poly-like) cell lines.