The present review may be helpful to future studies that further examine the molecular mechanism of keloid etiology as well as investigate the anti-keloid property in natural compounds.

Yongsanguanchai N, Pongrakhananon V, Mutirangura A, Rojanasakul Y, Chanvorachote P. Nitric oxide induces cancer stem cell-like phenotypes in human lung cancer cells. Am J Physiol Cell Physiol 308: C89 -C100, 2015. First published November 19, 2014; doi:10.1152/ajpcell.00187.2014.-Even though tremendous advances have been made in the treatment of cancers during the past decades, the success rate among patients with cancer is still dismal, largely because of problems associated with chemo/radioresistance and relapse. Emerging evidence has indicated that cancer stem cells (CSCs) are behind the resistance and recurrence problems, but our understanding of their regulation is limited. Rapid reversible changes of CSC-like cells within tumors may result from the effect of biological mediators found in the tumor microenvironment. Here we show how nitric oxide (NO), a key cellular modulator whose level is elevated in many tumors, affects CSC-like phenotypes of human non-small cell lung carcinoma H292 and H460 cells. Exposure of NO gradually altered the cell morphology toward mesenchymal stem-like shape. NO exposure promoted CSC-like phenotype, indicated by increased expression of known CSC markers, CD133 and ALDH1A1, in the exposed cells. These effects of NO on stemness were reversible after cessation of the NO treatment for 7 days. Furthermore, such effect was reproducible using another NO donor, S-nitroso-Nacetylpenicillamine. Importantly, inhibition of NO by the known NO scavenger 2-(4-carboxy-phenyl)-4,4,5,5 tetramethylimidazoline-1-oxy-3-oxide strongly inhibited CSC-like aggressive cellular behavior and marker expression. Last, we unveiled the underlying mechanism of NO action through the activation of caveolin-1 (Cav-1), which is upregulated by NO and is responsible for the aggressive behavior of the cells, including anoikis resistance, anchorage-independent cell growth, and increased cell migration and invasion. These findings indicate a novel role of NO in CSC regulation and its importance in aggressive cancer behaviors through Cav-1 upregulation.cancer stem cells; nitric oxide; caveolin-1; CD133; ALDH1A1; nonsmall cell lung carcinoma ACCORDING TO THE AMERICAN CANCER SOCIETY 2013 annual cancer statistics, lung cancer remains one of the most common malignancies and is the leading cause of cancer-related deaths worldwide (61). Increasing evidence has indicated the role of cancer stem cells (CSCs) in cancer aggressiveness, chemoresistance, and relapse; they are being considered as the underlying causes of the high mortality rate of cancer (29,47,50,55). The concept of a tumor having a heterogeneous cancer cell population with a subpopulation of cells possessing a high tumorigenic potential and stem-like property was first described in 1997 (5). This subpopulation is commonly known as tumor-initiating cells, tumor-propagating cells, or CSCs and has been identified in many types of cancer (16,23,40,46,56,58,63). CSCs have been suggested as the rationale behind chemo/radioresistance and cancer relapse (3,4,18,39,68) an...