The concept of epithelial‐mesenchymal transition (EMT), a process where cells change their epithelial towards a mesenchymal phenotype, has gained overwhelming attention especially in the cancer research community. Thousands of scientific reports investigated changes in gene, mRNA and protein expression compatible with EMT and their possible correlation with tumor invasion, metastatic spread or patient prognosis; however, up to now, a proof of clinical significance of the concept is still missing. This review, with a main focus on the role of EMT in tumors, will summarize the basic molecular events underlying EMT including the signaling pathways capable of its induction as well as changes in EMT‐associated protein expression and will very briefly touch the role of microRNAs in EMT. We then outline protein markers that are used most frequently for the assessment of EMT in research and diagnostic evaluation of tumor specimens and depict the link between EMT, a cancer stem cell (CSC) phenotype and resistance to conventional antineoplastic therapies. Furthermore, we evaluate a possible correlation between EMT marker expression and patient prognosis as well as current therapeutic concepts targeting the EMT process to slow down or prevent metastatic spread of malignant tumors.

Background: Fibronectin 1 (FN1) is a glycoprotein involved in cellular adhesion and migration processes. The aim of this study was to elucidate the role of FN1 in development of renal cell cancer (RCC) and to determine a prognostic relevance for optimal clinical management. Methods: 212 renal tissue samples (109 RCC, 86 corresponding tissues from adjacent normal renal tissue and 17 oncocytomas) were collected from patients undergoing surgery for renal tumors and subjected to total RNA extraction. Detection of FN1 mRNA expression was performed using quantitative real time PCR, three endogenous controls, renal proximal tubular epithelial cells (RPTEC) as biological control and the ΔΔCt method for calculation of relative quantities. Results: Mean tissue specific FN1 mRNA expression was found to be increased approximately seven fold comparing RCC and corresponding kidney control tissues (p < 0.001; ANOVA). Furthermore, tissue specific mean FN1 expression was increased approx. 11 fold in clear cell compared to papillary RCC (p = 9×10^-5; Wilcoxon rank sum test). Patients with advanced disease had higher FN1 expression when compared to organ-confined disease (p < 0.001; Wilcoxon rank sum test). Applying subgroup analysis we found a significantly higher FN1 mRNA expression between organ-confined and advanced disease in the papillary and not in the clear cell RCC group (p = 0.02 vs. p = 0.2; Wilcoxon rank sum test). There was an increased expression in RCC compared to oncocytoma (p = 0.016; ANOVA). Conclusions: To our knowledge, this is the first study to show that FN1 mRNA expression is higher in RCC compared to normal renal tissue. FN1 mRNA expression might serve as a marker for RCC aggressiveness, indicating early systemic progression particularly for patients with papillary RCC.

Background: Naturally occurring CD4⁺CD25⁺ regulatory T cells (T_Reg) are involved in the control of autoimmune diseases, transplantation tolerance, and anti-tumor immunity. Thus far, genomic studies on T_Reg cells were restricted to murine systems, and requirements for their development, maintenance, and mode of action in humans are poorly defined. Results: To improve characterization of human T_Reg cells, we compiled a unique microarray consisting of 350 T_Reg cell associated genes (Human T_Reg Chip) based on whole genome transcription data from human and mouse T_Reg cells. T_Reg cell specific gene signatures were created from 11 individual healthy donors. Statistical analysis identified 62 genes differentially expressed in T_Reg cells, emphasizing some cross-species differences between mice and humans. Among them, several 'old friends' (including FOXP3, CTLA4, and CCR7) that are known to be involved in T_Reg cell function were recovered. Strikingly, the vast majority of genes identified had not previously been associated with human T_Reg cells (including LGALS3, TIAF1, and TRAF1). Most of these 'new players' however, have been described in the pathogenesis of autoimmunity. Real-time RT-PCR of selected genes validated our microarray results. Pathway analysis was applied to extract signaling modules underlying human T_Reg cell function. Conclusion: The comprehensive set of genes reported here provides a defined starting point to unravel the unique characteristics of human T_Reg cells. The Human T_Reg Chip constructed and validated here is available to the scientific community and is a useful tool with which to study the molecular mechanisms that orchestrate T_Reg cells under physiologic and diseased conditions.

To evaluate the prognostic significance of the pre-operative C-reactive protein (CRP) serum level in patients with renal cell cancer (RCC).

Up to 50% of penile squamous cell carcinomas (pSCC) develop in the context of high-risk human papillomavirus (HR-HPV) infection. Most of these tumours have been reported to show basaloid differentiation and overexpression of tumour suppressor protein p16INK4a. Whether HPV-triggered carcinogenesis in pSCC has an impact on tumour aggressiveness, however, is still subject to research. In tissue specimens from 58 patients with surgically treated pSCC between 1995 and 2012, we performed p16INK4a immunohistochemistry and DNA extraction followed by HPV subtyping using a PCR-based approach. The results were correlated with histopathological and clinical parameters. 90.4% of tumours were of conventional (keratinizing) subtype. HR-HPV DNA was detected in 29.3%, and a variety of p16INK4a staining patterns was observed in 58.6% of samples regardless of histologic subtype. Sensitivity of basaloid subtype to predict HR-HPV positivity was poor (11.8%). In contrast, sensitivity and specificity of p16INK4a staining to predict presence of HR-HPV DNA was 100% and 57%, respectively. By focussing on those samples with intense nuclear staining pattern for p16INK4a, specificity could be improved to 83%. Both expression of p16INK4a and presence of HR-HPV DNA, but not histologic grade, were inversely associated with pSCC tumour invasion (p = 0.01, p = 0.03, and p = 0.71). However, none of these correlated with nodal involvement or distant metastasis. In contrast to pathological tumour stage, the HR-HPV status, histologic grade, and p16INK4a positivity failed to predict cancer-specific survival. Our results confirm intense nuclear positivity for p16INK4a, rather than histologic subtype, as a good predictor for presence of HR-HPV DNA in pSCC. HR-HPV / p16INK4a positivity, independent of histological tumour grade, indicates a less aggressive local behaviour; however, its value as an independent prognostic indicator remains to be determined. Since local invasion can be judged without p16INK4a/HPV-detection on microscopic evaluation, our study argues against routine testing in the setting of pSCC.