Hedgehog (Hh) signaling has been found to be activated in breast cancer stem cells (BCSCs). However, the precise role of the BCSCs marker, CD24, remains unclear. Here, we describe a relationship between CD24 and Sonic Hedgehog (SHH), and reveal a role for this relationship in the induction of a malignant phenotype of breast cancer. CD24 siRNA-transfected breast cancer cells (BCCs) demonstrated higher expression of SHH and GLI1, increased anchorage-independent proliferation, and enhanced invasiveness and superior tumorigenicity compared with control. Conversely, CD24 forced-expressing BCCs possessed decreased SHH and GLI1 expression, anchorage-independent proliferation, and invasiveness. Suppression of SHH decreased invasiveness through inhibition of matrix metalloproteinase (MMP)-2 expression, GLI1 expression, anchorage-independent proliferation, tumorigenicity, and tumor volume in vivo in CD24 siRNA transfected BCCs. DNA microarray analysis identified STAT1 as a relationship between CD24 and SHH. CD24 siRNA-transfected BCCs with concurrent STAT1 inhibition exhibited decreased SHH expression, invasiveness, anchorage-independent proliferation, tumorigenicity, and tumor volume in vivo. These results suggest that CD24 suppresses development of a malignant phenotype by down-regulating SHH transcription through STAT1 inhibition. CD24 gene transfer or STAT1 inhibition may represent new effective therapeutic strategies to target refractory breast cancer.

Hedgehog signal is re-activated in several cancers. In this study, we examined the role of Gli3 on malignant phenotype of tumorigenicity for colorectal cancer and its relationship with p53, WNT and ERK ⁄ AKT signals. Gli3 expression was detected in HT29 and SW480 (p53-mutant) cells, but not in DLD-1 (p53-mutant) or HCT116 (p53-wild type) cells by reverse transcription-polymerase chain reaction and immunocytochemistry. Full-length Gli3 transfection increased anchor-independent growth for all cells regardless of p53 status, with upregulation of adhesion-related genes. Exogenous Sonic-Hedgehog increased activator-type of Gli3 and colony formation in Gli3-positive HT29 and SW480 cells. After implantation of Gli3-FL or mock-transfectant DLD-1 cells into SCID /fc> mice, tumor formation was highly observed in only Gli3-FL-transfectant group. In clinical specimens, Gli3 expression was detected in subsets of colorectal cancer and related with poorly-differentiated histological type, while Sonic-Hedgehog was present with high incidence. In conclusion, activator Gli3 signal augments tumorigenicity of colorectal cancer irrespective of p53 status. (Cancer Sci 2013; 104: 328-336)

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Antileukemic activities of more than 30 2,5-bis(1-aziridinyl)-p-benzoquinones (4) were correlated against well-defined physicochemical constants. These compounds were evaluated against lymphoid leukemia L1210 in BDF1 mice. The best equations obtained exhibited a linear dependence on the hydrophobic constant, pi. Characteristic aspects of the equations are that the larger the relative hydrophilicity of the drugs the stronger the antileukemic activity will be and that the more hydrophilic compounds have a greater chemotherapeutic index. Steric and electronic effects were also determined to be important. Based on the correlations, three compounds (11, 15 and 19) were designed, synthesized, and biologically evaluated.

High doses of glycine have been reported to improve negative schizophrenic symptoms, suggesting that ingested glycine activates glutamatergic transmission via N-methyl-D-aspartate (NMDA) receptors. However, the pharmacokinetics of administered glycine in the brain has not been evaluated. In the present study, the time- and dose-dependent distributions of administered glycine were investigated from a pharmacokinetic viewpoint. Whole-body autoradiography of radiolabeled glycine was performed, and time-concentration curves for glycine and serine in plasma, cerebrospinal fluid (CSF), and brain tissues were obtained. Furthermore, pharmacokinetic parameters were calculated. For a more detailed analysis, the amount of glycine uptake in the brain was evaluated using the brain uptake index method. Radiolabeled glycine was distributed among periventricular organs in the brain. Oral administration of 2 g/kg of glycine significantly elevated the CSF glycine concentration above the ED50 value for NMDA receptors. The glycine levels in CSF were 100 times lower than those in plasma. Glycine levels were elevated in brain tissue, but with a slower time-course than in CSF. Serine, a major metabolite of glycine, was elevated in plasma, CSF, and brain tissue. Glycine uptake in brain tissue increased in a dose-dependent manner. Time-concentration curves revealed that glycine was most likely transported via the blood-CSF barrier and activated NMDA receptors adjacent to the ventricles. The pharmacokinetic analysis and the brain uptake index for glycine suggested that glycine was transported into brain tissue by passive diffusion. These results provide further insight into the potential therapeutic applications of glycine.