Cyclin D3 deficiency inhibits skin tumor development, but does not affect normal keratinocyte proliferation

The mechanism of the contribution of ICAM-1 to epithelial-mesenchymal transition (EMT) in bladder cancer

Bladder cancer is one of the most prevalent cancers worldwide. Moreover, if not optimally treated, bladder cancer is a significant burden on healthcare systems due to multiple recurrences which often require more aggressive therapies. Therefore, targeted anti-cancer therapies, developed based on an in-depth understanding of specific proteins and molecular mechanisms, are promising in cancer treatment. Here, for the first time, we presented the new approaches indicating that intracellular adhesion molecule-1 (ICAM-1) may play a potential role in enhancing therapeutic effectiveness for bladder cancer. In the present study, we presented that ICAM-1 expression as well as its regulation in bladder cancer is strongly correlated with the high expression of N-cadherin. Importantly, the presence of N-cadherin and its regulator-TWIST-1 was abolished when ICAM-1 was silenced. We identified also that ICAM-1 is capable of regulating cellular migration, proliferation, and EMT progression in bladder cancer cells via the N-cadherin/SRC/AKT/GSK-3β/β-catenin signaling axis. Therefore, we propose ICAM-1 as a novel metastatic marker for EMT progression, which may also be used as a therapeutic target in bladder cancer.

Cyclin-Dependent Kinase 4 expression alters the number of keratinocyte stem cells in the mouse hair follicle

Hair follicles regenerate periodically by spontaneously undergoing cycles of growth, regression, and relative quiescence. During the hair cycle, follicle stem cells residing in a specialized niche remain quiescent, and they are stimulated to proliferate throughout the growth phase of the hair follicle. Although cell cycle regulators play a prominent role during the activation of hair follicle stem cells, the identity and the role of these regulators have not been confirmed. Herein, we reported that stem cells located in the bulge region of the HF (BuSCs) express high levels of cyclin‐dependent kinase 4 (CDK4) through the quiescent phase of the hair cycle. Using gain‐ and loss‐of‐function studies, we have determined that the CDK4 protein level affects the number of BuSCs. Transgenic expression of CDK4 in the bulge region of the hair follicles reduces the number of BuSCs, whereas CDK4 ablation resulted in an increasing number of BuSCs. These results suggest that deregulation of CDK4 protein levels contributes to distorting the self‐renewal/proliferation balance and, in turn, altering the number of BuSCs.