RESUMO
The theory of cancer stem cells (CSCs) provides a new perspective for the study of cancer. CSCs doctrine presumes that tumor cells are heterogeneity, and there are cancer stem-like cells in tumors, whose proliferation is uncon-trolled. The cancer stem-like cells could form tumors from only few cells, who only account for a very small part of all the tu-mor cells. These cells with stem cells characteristics could form different extend of differentiation of tumor cells and work as source of tumor growth, recurrence and metastasis. miRNAs are widely-existed non-coding small RNAs, which regulate 1/3 of all human genes and participate in a series of essential processes of life. More and more evidences indicate that miRNAs contribute significantly to cancer generation and development. They may exhibit oncogenic activity and act as tumor suppres-sors. As one of the post-transcriptional controlling factors, they regulate biological processes of tumor related genes exten-sively and specific miRNAs expression profiles were shown in different cancers. The research of miRNA about CSCs has be-come very hot. Some studies have confirmed that miRNAs play a very important role in a variety of CSCs, which act as a new target for tumor therapy. Researchers have found that some specific miRNAs express in plasma of cancer patients, which can be used as tumor markers to assist diagnosis and prognosis. This review focused on current progress of research in function of miRNAs in CSCs and its role as tumor markers.