Recent evidence has unveiled the critical role of tumor cells with stem cell activities in tumorigenicity and drug resistance, but how tumor microenvironments regulate cancer stem/initiating cells (CSCs) remains unknown. We clarified the role of tumor-associated macrophages (TAMs) and their downstream factor milk-fat globule-epidermal growth factor-VIII (MFG-E8) in the regulation of CSC activit...

Reduced oxygenation, or hypoxia, inhibits differentiation and facilitates stem cell maintenance. Hypoxia commonly occurs in solid tumors and promotes malignant progression. Hypoxic tumors are aggressive and exhibit stem cell-like characteristics. It remains unclear, however, whether and how hypoxia regulates cancer cell differentiation and maintains cancer cell stemness. Here, we show that hypo...

Some chemicals are known to be lung carcinogens in rodents. While many studies using two-stage models have administered medium or high doses to mice, few have tested lower doses. The dose dependence of urethane, 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and benzo[a]pyrene (B[a]P), three well-known lung carcinogens at high doses, has not been sufficiently reported in lower dose ...

Retroviruses are believed to induce tumors by acting as insertional mutagens that activate expression of cellular protooncogenes. Indeed, almost 90% of mouse mammary tumor virus (MMTV)-induced mammary tumors in C3H/He mice show upregulation of Int protooncogenes. We have analyzed three different MMTV variants [MMTV(C3H), MMTV(HeJ), and a genetically engineered MMTV hybrid provirus (HP)] for tum...

The kinetics of neutral amino acid transport were examined in isogeneic matched pairs of hybrid cells, one member of each pair being tumorigenic, the other not. The L system of transport, which is sodium-independent, was measured by the uptake of leucine, and the A system, which is sodium-dependent, by the uptake of methylaminoisobutyric acid. Although there was variation from one cell type to ...

We generated a p27(Kip1) mutant (p27deltaNLS) that localized exclusively in cell cytosol. Expression of p27deltaNLS in MCF7 breast cancer cells down-regulated RhoA and increased motility, survival, and Akt levels without an effect on cell cycle distribution. RNA interference of p27 in U87 glioma cells, which express p27 predominantly in the cytoplasm, inhibited motility and survival. Conversely...

BACKGROUND The green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) possesses anti-carcinogenic properties and was found to induce terminal differentiation in epidermal keratinocytes. Caspase-14, a member of the caspase family associated with epithelial cell differentiation, planned cell death, and barrier formation, is induced by EGCG in normal human epidermal keratinocytes but not in ca...