Aim Humor has long been considered as an effective emotion regulation strategy for people vulnerable to depression, but empirical evidence in this area is scarce. To address this issue, we investigated the emotional consequences of humor in remitted depressed patients and compared them with the effects of positive reappraisal and spontaneous emotion regulation. Methods Fifty‐five patients with remitted major depression took part in a laboratory computer experiment in which they were shown negative pictures twice. First, the patients simply viewed the pictures and rated their reactions. Second, they viewed each of the pictures according to instructions, which are to (a) use humor, (b) use positive reappraisal, or (c) simply view the pictures, and then, they again rated their reactions. Results Humor was found to decrease negative emotions, increase positive emotions, and enhance the distance from adversity; it was more effective than spontaneous emotion regulation and similarly as effective as positive reappraisal. Humor was the most effortful form of emotion regulation. Patients were able to successfully produce humorous comments, and their failure to do so did not lead to worse emotional outcomes than regulating emotions spontaneously. The analyses also indicated that distancing mediates between using humor and the intensity of positive and negative emotions. Conclusions Our findings provide preliminary empirical support for the idea that for individuals vulnerable to depression, humor can be an adaptive tool in dealing with negative responses to aversive events, and, thus, it may impair their potential of these events to trigger depressive episodes. Further studies in this area are warranted to determine the most adaptive forms of humor and analyze their effects in various depressogenic contexts.

BackgroundCD105 was postulated as a renal cell carcinoma (RCC) stem cell marker, and CD133 as a putative RCC progenitor. Hypoxia, a natural microenvironment that prevails in tumors, was also incorporated into the study, especially in terms of the promotion of hypothetical stem-like cell properties.MethodsWithin this study, we verify the existence of CD105+ and CD133+ populations in selected papillary subtype RCC (pRCC) cell lines. Both populations were analyzed for correlation with stem-like cell properties, such as stemness gene expression, and sphere and colony formation. For the preliminary analysis, several RCC cell lines were chosen (786-O, SMKT-R2, Caki-2, 796-P, ACHN, RCC6) and the control was human kidney cancer stem cells (HKCSC) and renal cells of embryonic origin (ASE-5063). Four cell lines were chosen for further investigation: Caki-2 (one of the highest numbers of CD105+ cells; primary origin), ACHN (a low number of CD105+ cells; metastatic origin), HKCSC (putative positive control), and ASE-5063 (additional control).ResultsIn 769-P and RCC6, we could not detect a CD105+ population. Hypoxia variously affects pRCC cell growth, and mainly diminishes the stem-like properties of cells. Furthermore, we could not observe the correlation of CD105 and/or CD133 expression with the enhancement of stem-like properties.ConclusionsBased on this analysis, CD105/CD133 cannot be validated as cancer stem cell markers of pRCC cell lines.

Renal cell carcinoma (RCC) is the most lethal of the common urologic malignancies, comprising 3% of all human neoplasms, and the incidence of kidney cancer is rising annually. We need new approaches to target tumor cells that are resistant to current therapies and that give rise to recurrence and treatment failure. In this study, we focused on low oxygen tension and three-dimensional (3D) cell culture incorporation to develop a new RCC growth model. We used the hanging drop and colony formation methods, which are common in 3D culture, as well as a unique methylcellulose (MC) method. For the experiments, we used human primary RCC cell lines, metastatic RCC cell lines, human kidney cancer stem cells, and human healthy epithelial cells. In the hanging drop assay, we verified the potential of various cell lines to create solid aggregates in hypoxic and normoxic conditions. With the semi-soft agar method, we also determined the ability of various cell lines to create colonies under different oxygen conditions. Different cell behavior observed in the MC method versus the hanging drop and colony formation assays suggests that these three assays may be useful to test various cell properties. However, MC seems to be a particularly valuable alternative for 3D cell culture, as its higher efficiency of aggregate formation and serum independency are of interest in different areas of cancer biology.