Objective This study aimed to explore the effects of overexpression of sirtuin 6 (SIRT6) on the tumorigenicity of hepatocellular carcinoma (HCC) cells. Methods Stable SIRT6-overexpressed HCC cell lines were established by transfecting SIRT6 plasmid. Soft agar assay and tumor xenograft assay in nude mice were applied. Flow cytometry was employed to detect cell cycle distribution. Western blott...

Continuous epithelial-like cell lines derived from normal adult rat liver and hepatocarcinomas were evaluated for their growth in soft agar and five properties of the cell membrane as markers for neoplastic transformation. A correlation of these properties was made to the tumorigenicity of the lines in nude mice. Growth in soft agar was a specific and sensitive marker, whereas the data on uptak...

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 hyp...

The tumorigenicity of cell clones of the same histogenetic origin but with different dexamethasone sensitivities and states of differentiation was examined. Neither the degree of differentiation nor the glucocorticoid resistance influenced the tumor-forming capacity of Reuber rat hepatoma clones in nude mice. However, the tumorigenicity of independently isolated resistant clones maintained in v...

Human pluripotent stem cells (PSC) have the potential to revolutionize regenerative medicine. However undifferentiated PSC can form tumors and strict quality control measures and safety studies must be conducted before clinical translation. Here we describe preclinical tumorigenicity and biodistribution safety studies that were required by the US Food and Drug Administration (FDA) and Australia...

Mild oxidative stress is known to induce premature senescence, termed stress-induced premature senescence (SIPS), in normal human diploid cells. We investigated to determine whether mild oxidative stress would trigger SIPS in a human tumor cell line, human lung adenocarcinoma A549. The results showed that sublethal concentrations of H(2)O(2) induced SIPS in A549 cells and consequently attenuate...