The evolving concept of liver cancer stem cells

Liver cancer is an often fatal malignant tumor with a high recurrence rate and chemoresistance. The major malignant phenotypes of cancer, including recurrence, metastasis, and chemoresistance, are related to the presence of cancer stem cells (CSCs). In the past few decades, CSCs have been identified and characterized in many tumors including liver cancer. Accumulated evidence has revealed many aspects of the biological behavior of liver CSCs and the mechanism of their regulation. Based on these findings, a number of studies have investigated eradication of liver CSCs. This review focuses on the recent advances in our understanding of the biology of liver CSCs and the development of strategies for their treatment

Superconducting nanowire single-photon detectors with non-periodic dielectric multilayers

We present superconducting nanowire single-photon detectors (SSPDs) on non-periodic dielectric multilayers, which enable us to design a variety of wavelength dependences of optical absorptance by optimizing the dielectric multilayer. By adopting a robust simulation to optimize the dielectric multilayer, we designed three types of SSPDs with target wavelengths of 500 nm, 800 nm, and telecom range respectively. We fabricated SSPDs based on the optimized designs for 500 and 800 nm, and evaluated the system detection efficiency at various wavelengths. The results obtained confirm that the designed SSPDs with non-periodic dielectric multilayers worked well. This versatile device structure can be effective for multidisciplinary applications in fields such as the life sciences and remote sensing that require high efficiency over a precise spectral range and strong signal rejection at other wavelengths

Wnt/beta-catenin signaling activates microRNA-181 expression in hepatocellular carcinoma

<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) is a malignant cancer with an observable heterogeneity and microRNAs are functionally associated with the tumorigenesis of HCC. We recently identified that EpCAM (CD326)-positive cells isolated from alpha-fetoprotein (AFP)-positive HCC samples are hepatic cancer stem cells (HepCSCs). EpCAM⁺AFP⁺HepCSCs have an activated Wnt/β-catenin signaling with a parallel increased expression of all four microRNA-181 family members. We hypothesized that Wnt/β-catenin signaling transcriptionally activates microRNA-181s in HCC.</p> <p>Results</p> <p>Using both western blot and quantitative reverse transcriptase-PCR analyses, we found that the expression of all four microRNA-181 family members was positively correlated with β-catenin expression in HCC cell lines. MicroRNA-181 expression could be directly induced upon an activation of Wnt/β-catenin signaling, which includes Wnt10B overexpression, inhibition of GSK3β signaling by LiCl, or forced expression of β-catenin/Tcf4. Moreover, microRNA-181 expression was inhibited upon an inactivation of Wnt/β-catenin signaling by an induction of adenomatosis polyposis coli (APC) expression or silencing β-catenin via RNA interference. In addition, seven putative β-catenin/Tcf4 binding sites were identified in the promoter region of the microRNA-181a-2 and microRNA-181b-2 transcripts. Consistently, we found that Tcf4 interacted with these regions <it>in vivo </it>using chromatin immunoprecipitation assay.</p> <p>Conclusions</p> <p>Taken together, our results demonstrate that microRNA-181s are transcriptionally activated by the Wnt/beta-catenin signaling pathway in HCC.</p