Visualization of cancer initiating cell in the vascular niche utilized with transcriptional activity of PSF1

Identification of cancer stem/initiating cells (CSCs/CICs) by a specific marker is useful for diagnosis and therapy of cancer. We have determined that PSF1 which plays a role in DNA replication in lower species is strongly expressed in wide range of normal stem cell population. Here, utilizing the transcriptional activity of PSF1 promoter in tumor cell xenograft model, we show that PSF1high cancer cells display malignant features including high proliferating activity, serial transplantation potential, and metastatic ability those are used for criteria of CSCs/CICs. PSF1high cancer cells localize in perivascular region and genetically display ES cell like signature. Silencing of PSF1 by RNAi inhibited growth of cancer cells mediated by disruption of DNA synthesis and chromosomal segregation. These suggested that PSF1 is a possible maker and a molecular target of CSCs/CICs.

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