CONTROL OF CELL MULTI-LAYERING DURING MALIGNANCY

Abstract

The molecular mechanism that facilitates the stratification of keratinocytes is still unclear. We describe here a novel role of an atypical GTP-binding protein RhoE in promoting differentiation and stratification of keratinocytes. Upon upregulation of RhoE and subsequent calcium-induced differentiation, actin purse-string that is typically found during cell extrusion was not observed. Quantitative image analysis over collected images of control and RhoE-expressing cells from the experiment was performed. We found that E-cadherin levels were downregulated along the stratified cell-cell contacts of RhoE-expressing cells after 3 and 6 hours induction of differentiation. Similarly, F-actin levels were depleted along basal and stratified cell-cell contacts after 6 hours of stratification assay. Together, our findings suggest that RhoE promotes keratinocytes stratification without involving cell extrusion mechanisms but instead by modulating E-cadherin and F-actin levels along cell-cell contacts.