Lingual keratinized epithelial cells, which constitute the filiform papillae of the tongue, have one of the most rapid tissue turnover rates in the mammalian body and are thought to be the source of squamous cell carcinoma of the tongue. However, the mechanism of tissue maintenance and regeneration is largely unknown for these cells. Here, we show that stem cells positive for Bmi1, keratin 14 and keratin 5 are present in the base but not at the very bottom of the interpapillary pit (observed most frequently in the second or third layer (position +2 or +3) from the basal cells). Using a multicolour lineage tracing method, we demonstrated that one stem cell per interpapillary pit survives long-term. The cells were shown to be unipotent stem cells for keratinized epithelial cells but not for taste bud cells, and were found to usually be in a slow-growing or resting state; however, on irradiation-induced injury, the cells rapidly entered the cell cycle and regenerated tongue epithelium. The elimination of Bmi1-positive stem cells significantly suppressed the regeneration. Taken together, these results suggest that the stem cells identified in this study are important for tissue maintenance and regeneration of the lingual epithelium.

Asingle cells in undifferentiated spermatogonia are considered to be the most primitive forms of germ stem cells (GSCs). Although GFRα1 is thought to be a marker of Asingle cells, we found that Bmi1High is more specific than GFRα1 for Asingle cells. Bmi1High expression in Asingle cells is correlated with seminiferous stages, and its expression was followed by the proliferative stage of Asingle GSCs. In contrast, GFRα1 expression was seminiferous stage-independent. Fate analyses of EdU-positive Bmi1High-positive cell-derived Asingle cells revealed that these cells self-renewed or generated transient amplifying Apaired cells. Bmi1High-positive cells were resistant to irradiation-induced injury, after which they regenerated. Elimination of Bmi1High-positive cells from seminiferous tubules resulted in the appearance of tubules with seminiferous stage mismatches. Thus, in this study, we found that Bmi1High is a seminiferous stage-dependent marker for long-term GSCs and that Bmi1High-positive cells play important roles in maintaining GSCs and in regenerating spermatogenic progenitors after injury.

Despite the strong need for the establishment of a lingual epithelial cell culture system, a simple and convenient culture method has not yet been established. Here, we report the establishment of a novel lingual epithelium organoid culture system using a three-dimensional matrix and growth factors. Histological analyses showed that the generated organoids had both a stratified squamous epithelial cell layer and a stratum corneum. Very recently, we showed via a multicolor lineage tracing method that Bmi1-positive stem cells exist at the base of the epithelial basal layer in the interpapillary pit. Using our new culture system, we found that organoids could be generated by single Bmi1-positive stem cells and that in the established organoids, multiple Bmi1-positive stem cells were generated at the outermost layer. Moreover, we observed that organoids harvested at an early point in culture could be engrafted and maturate in the tongue of recipient mice and that the organoids generated from carcinogen-treated mice had an abnormal morphology. Thus, this culture system presents valuable settings for studying not only the regulatory mechanisms of lingual epithelium but also lingual regeneration and carcinogenesis.

Introduction: No studies have shown whether the enhanced recovery after surgery (ERAS) protocol is superior to the conventional protocol after robot-assisted laparoscopic radical prostatectomy (RALP). We compared intestinal function and perioperative parameters of patients with prostate cancer after the ERAS and conventional protocols to determine the superior protocol for recovery of intestinal function. Material and Methods: A retrospective analysis of 198 consecutive patients who underwent RALP between August 2013 and June 2015 was conducted. Our study design included 2 cohorts. Patients underwent conventional care in one group (n = 123) and the ERAS protocol in the other group (n = 75). The primary outcome was the time to first defecation. Secondary outcomes were perioperative parameters and the complication rate. Results: The ERAS group showed a significantly shorter time to first defecation than did the conventional group (p = 0.006). Multivariate analysis showed that selection of the ERAS protocol was significantly associated with the number of days for first time to defecation. Conclusions: Successful application of an ERAS protocol was applied to our patients who underwent RALP and did not have major complications. The ERAS protocol included enhanced intestinal recovery. The ERAS group showed a significantly shorter time to first defecation than did the conventional group.

Various systemic inflammatory response biomarkers are associated with oncological outcome. We evaluated the superiority of prognostic predictive accuracy between neutrophil-lymphocyte ratio (NLR) and lymphocyte-monocyte ratio (LMR), and the prognostic significance of their perioperative change in patients with bladder cancer undergoing radical cystectomy (RC). We retrospectively analyzed 302 patients who had undergone RC in four institutions. Comparison of predictive accuracy between NLR and LMR was performed using receiver operating characteristic curve analysis. Overall survival (OS) and cancer-specific survival (CSS) were assessed with the Kaplan-Meier method and Cox regression analysis. Preoperative and postoperative LMR showed higher predictive accuracy for OS than NLR did (p = 0.034). Applying a cutoff of 3.41, change in perioperative LMR stratified patients into three groups (low, intermediate, and high risk), showing a significant difference in OS and CSS (p < 0.001, each), and pathological outcomes. Multivariable analyses for OS and CSS showed that poor changes in LMR (high risk) were an independent prognostic factor (hazard ratio 5.70, 95 % confidence interval 3.49-9.32, p < 0.001; hazard ratio 4.53, 95 % confidence interval 2.63-7.82, p < 0.001; respectively). Perioperative LMR is significantly associated with survival in patients with bladder cancer after RC, and it is possibly superior to NLR as a prognostic factor.