Supplementary Materialsoncotarget-05-9498-s001. of irregular divisions was higher in TOP2Ahigh cells. Our studies demonstrate Kynurenic acid sodium that TOP2Ahigh is the phenotype of recurrence/metastasis but TOP2Aneg cells show slow cycling and have CSCs properties in prostate malignancy, which has significant implications for prostate malignancy therapy. strong class=”kwd-title” Keywords: prostate malignancy, malignancy stem cells, TOP2A, recurrence, metastasis Intro Prostate malignancy is one of the most common cancers worldwide. Relating to recent global malignancy statistics, it is the second most diagnosed and sixth leading cause of malignancy deaths in males . Although early stage prostate malignancy can be surgically excised and efficiently treated by androgen blockade, chemotherapy or radiotherapy, recurrent and metastatic diseases are common and fatal. Over the past decades, a large number of studies have focused on recurrent and metastatic prostate malignancy (referred to as secondary prostate malignancy hereafter), which is definitely often androgen-independent and chemotherapy-resistant. Several mechanisms that may lead to tumor recurrence/metastasis have been proposed, including the amplification or mutation of androgen receptor [2C4], Rabbit Polyclonal to CROT manifestation of multidrug resistance gene [5, 6], epithelial-mesenchymal transition (EMT) Kynurenic acid sodium [7C9] and malignancy stem cells (CSCs) or malignancy stem cell-like cells [8, 10C12]. CSC model was originally launched by Mackillop et al.  and validated in Kynurenic acid sodium acute myeloid leukemia (AML) for the first time in 1997 . With this model, cancers are supposed to retain hierarchical business in much the same way as normal cells and CSCs constitute a small subset of tumor cells, which are functionally unique from non-CSCs by their ability to seed fresh tumors. CSCs have been consequently recognized in a variety of human being cancers, such as breast cancer , mind malignancy , pancreatic malignancy , liver malignancy , and prostate malignancy . Therefore, recognition of novel markers for CSCs is definitely of importance and may offer more effective therapies for malignancy patients. In this study, we systematically analyzed genes upregulated in secondary prostate malignancy and identified TOP2A to be at the very top of the list. TOP2A encodes topoisomerase IIa (topoIIa), an enzyme involved in DNA replication, transcription, recombination, and chromatin redesigning . It takes on an important part in DNA synthesis and transcription and has been implicated in a variety of human being cancers . It is usually assumed that CSCs are enriched in relapsed or disseminated tumors, and genes upregulated in recurrence/metastasis are likely markers for the CSCs [22C24]. Consequently, we further investigated whether TOP2A was a potential CSC marker in prostate malignancy. Surprisingly, although TOP2Ahigh (high manifestation of TOP2A) cells were highly proliferative and were associated with recurrence/metastasis in prostate malignancy, CSCs were enriched in a small minority which was TOP2Aneg (undetectable manifestation of TOP2A by FACS in promoter reporter system). These cells displayed slow-cycling, higher tumorigenic potential and were more resistant to chemotherapy and additional stresses. Consequently, our findings argue for novel therapies targeting TOP2Aneg cells, in combination with standard de-bulking strategies, to eradicate all tumor cells in prostate malignancy patients. RESULTS Upregulation of TOP2A manifestation in secondary prostate malignancy To find out candidate genes that are crucial for prostate malignancy recurrence/metastasis, we analyzed 12 microarray datasets on prostate tumor studies (Table ?(Table1)1) and focused on the upregulated genes. The upregulated genes, duplication occasions and median fold changes in secondary prostate malignancy relative to main cancer are demonstrated in Supplemental Excel file 1. Thirty-five genes were found upregulated in more than four patient cohorts and TOP2A ranked at the very top, which showed improved manifestation in 6 out of.