Novel markers of squamous differentiation in the urinary bladder

Role of TRIM29 in disease: What is and is not known

Tripartite motif-containing proteins (TRIMs), comprising the greatest subfamily of E3 ubiquitin ligases with approximately 80 members of this family, are widely distributed in mammalian cells. TRIMs actively participate in ubiquitination of target proteins, a type of post-translational modification associated with protein degradation and other functions. Tripartite motif-containing protein 29 (TRIM29), a member of the TRIM family, differs from other members of this family in that it lacks the RING finger structural domain containing cysteine and histidine residues that mediates DNA binding, protein-protein interactions, and ubiquitin ligase, at its N-terminus. The expression of TRIM29 was initially found to be associated with cancer and diabetic nephropathy progression, and antiviral immunity which is triggered by virus-derived nucleic acids binding to pattern recognition receptors (PRRs) on immune cells. Recently, TRIM29 has also been explored as a diagnostic biomarker and therapeutic target for some immune-related diseases. Here, we review the functions of TRIM29 in the progression of diseases and the inherent mechanisms, as well as the remaining gaps in the literature. A thorough understanding of the detailed regulatory mechanisms of TRIM29 will ultimately facilitate the development of different therapeutic strategies for various diseases.

The impact of squamous cell transformation on the prognosis of patients treated with radical nephroureterectomy

BACKGROUND

Limited information is available for guiding the management of upper urinary tract (UUT) urothelial carcinoma with squamous differentiation (UC-SqD). We did not even know about the difference between pure urothelial carcinoma (UC) and UC-SqD in the UUT regardless of treatment policy and prognosis. Instead of direct comparisons against each other, we included the third UUT malignancy, squamous cell carcinoma (SCC). This three-way-race model allows us to more clearly demonstrate the impact of squamous cell transformation on patient outcomes in UUT malignancy.

METHODS

We retrospectively analysed 327 patients with UC, UC-SqD, or SCC who underwent radical nephroureterectomy with bladder cuff excision (RNU) at Taichung Veterans General Hospital, Taichung, Taiwan, between January 2006 and December 2013. A Kaplan-Meier survival analysis was used to evaluate the relationship between patient outcomes and histology. Multivariate Cox proportional hazards modelling was also used to predict patient prognoses.

RESULTS

The five-year postoperative cancer-specific survival (CSS) rates were 83.6% (UC), 74.4% (UC-SqD), and 55.6% (SCC), and the 5-year recurrence-free survival (RFS) rates were 87.7% (UC), 61.5% (UC-SqD), and 51.9% (SCC). UC patients had significantly better 5-year RFS than UC-SqD and SCC patients (P = 0.001 and P < 0.0001, respectively). Patients with pure UC had significantly better 5-year CSS than SCC patients (P = 0.0045). SCC or UC-SqD did not independently predict disease-specific mortality (HR 0.999, p = 0.999; HR 0.775, p = 0.632, respectively) or disease recurrence compared to pure UC (HR 2.934, p = 0.239; HR 1.422, p = 0.525, respectively). Age, lymphovascular invasion (LVI), and lymph node (LN) status independently predicted CSS, while pathological tumour stage, LN status, and LVI predicted RFS.

CONCLUSIONS

SCC and UC-SqD are not independent predictors of survival outcomes in patients with UUT tumours. However, they are associated with other worse prognostic factors. Hence, different treatments are needed for these two conditions, especially for SCC.

Role of human papillomavirus and associated viruses in bladder cancer: An updated review

Bladder cancer (BC) is a complex disease affecting the urinary system and is regulated by several carcinogenic factors. Viral infection is one such factor that has attracted extensive attention in BC. Human papillomavirus (HPV) is the most common sexually transmitted infection, and although multiple researchers have explored the role of HPV in BC, a consensus has not yet been reached. In addition, HPV-associated viruses (e.g., human immunodeficiency virus, herpes simplex virus, BK virus, and JC virus) appear to be responsible for the occurrence and progression of BC. This study systematically reviews the relationship between HPV-associated viruses and BC to elucidate the role of these viruses in the onset and progression of BC. In addition, the study aims to provide a greater insight into the biology of HPV-associated viruses, and assess potential strategies for treating virus-induced BC. The study additionally focuses on the rapid development of oncolytic viruses that provide a potentially novel option for the treatment of BC.

Identification of Novel Diagnostic Markers for Malignant Pleural Mesothelioma Using a Reverse Translational Approach Based on a Rare Synchronous Tumor

Although the routine use of immunohistochemistry has improved the accuracy of histopathologic diagnosis in clinical practice, new methods for discovering novel diagnostic markers are still needed. We sought new diagnostic markers for malignant pleural mesothelioma (MPM) using a reverse translational approach with limited archival tissues from a very rare case. Total RNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues of a synchronous collision tumor consisting of MPM and pulmonary adenocarcinoma (PAC) was employed for gene expression profiling (GEP) analysis. Among the 54 genes selected by GEP analysis, we finally identified the following two candidate MPM marker genes: PHGDH and TRIM29. Immunohistochemical analysis of 48 MM and 20 PAC cases showed that both PHGDH and TRIM29 had sensitivity and specificity almost equivalent to those of calretinin (sensitivity 50% and 46% vs. 63%, and specificity 95% and 100% vs. 100%, respectively). Importantly, of the 23 epithelioid MMs, all 3 calretinin-negative cases were positive for TRIM29. These two markers may be diagnostically useful for immunohistochemical distinction between MPMs and PACs. This successful reverse translational approach based on FFPE samples from one very rare case encourages the further use of such samples for the development of novel diagnostic markers.

TRIM29 in Cutaneous Squamous Cell Carcinoma

Tripartite motif (TRIM) proteins play important roles in a wide range of cell physiological processes, such as signal transduction, transcriptional regulation, innate immunity, and programmed cell death. TRIM29 protein, encoded by the ATDC gene, belongs to the RING-less group of TRIM protein family members. It consists of four zinc finger motifs in a B-box domain and a coiled-coil domain, and makes use of the B-box domain as E3 ubiquitin ligase in place of the RING. TRIM29 was found to be involved in the formation of homodimers and heterodimers in relation to DNA binding; additional studies have also demonstrated its role in carcinogenesis, DNA damage signaling, and the suppression of radiosensitivity. Recently, we reported that TRIM29 interacts with keratins and FAM83H to regulate keratin distribution. Further, in cutaneous SCC, the expression of TRIM29 is silenced by DNA methylation, leading to the loss of TRIM29 and promotion of keratinocyte migration. This paper reviews the role of TRIM family proteins in malignant tumors, especially the role of TRIM29 in cutaneous SCC.

Squamous differentiation is a potential biomarker predicting tumor progression in patients treated with pembrolizumab for urothelial carcinoma

Immune checkpoint inhibitor (ICI) is widely used and highly effective for some cancer patients but may result in disease progression in others. Hyperprogressive disease in particular is characterized by an acceleration of tumor growth during ICI therapy and has been reported in patients including those with urothelial carcinoma. Biomarkers predicting treatment efficacy are crucial to avoid tumor progression and unnecessary adverse effects. This study aims to clarify the predictors of disease progression for ICI treatment in patients with urothelial carcinoma. We analyzed the response pattern of 23 urothelial carcinomas treated with pembrolizumab and its association with pathological features and potential immunohistochemical markers including EGFR, MDM2, p53, p16, and programmed cell death ligand-1 (PD-L1) expression and CD8- and CD204-positive cell infiltration. During ICI therapy, 13 (57 %) patients showed progressive disease including 6 (26 %) with hyperprogressive disease. Notably, squamous differentiation combined with MAC387 expression was observed exclusively in cases with progressive disease (6 of 13, 46 %); it was not present in cases with stable disease or partial/complete response (0 of 10, p = 0.0019). All tumors with squamous differentiation showed positive staining for EGFR. Additionally, the loss of p16 expression occurred more frequently in cases with progressive disease (8 of 13, 62 %) than in other cases (3 of 10, 30 %), but this finding did not reach statistical significance. Squamous differentiation was also significantly associated with shorter overall survival. Based on our observations, squamous differentiation may be a novel biomarker for predicting disease progression in patients with urothelial carcinoma who receive pembrolizumab.

Urothelial carcinoma: variant histology, molecular subtyping, and immunophenotyping significant for treatment outcomes

Although urothelial carcinoma (UC) has been recognised as a homogenous disease entity until recently, it exhibits widely diverse histological variants. Recent studies have revealed that some histological variants may serve as markers of very high risk for advanced cancers and poor prognoses. Certain histological variants can generate a pathological T stage, which may result in unnecessary surgery. Though platinum based chemotherapy is the standard treatment, the use of immune checkpoint inhibitors (ICIs) for UC treatment has become a major trend in oncology. UCs showing specific histological variants have responded exceptionally well to chemotherapy and ICIs. Currently, molecular studies base molecular classification on gene expression profile signatures in order to make diagnoses or predict responses to chemotherapies and ICIs. Notably, some histological variants correlate with specific molecular subtypes. The usefulness of immunophenotyping for classification purposes was recognised only recently. Immunophenotypes are classified into three categories according to lymphocyte distribution in or around the cancer cell nest: desert, excluded, and inflamed. This immunophenotyping has been increasingly shown to be of value in predicting the response to ICIs. This review describes the morphological characteristics of histological variants as well as the advantages and limitations in determining them, with particular reference to clinical benefits. Subsequently, we describe the concept of molecular classification and immunophenotypes, and their morphological features, which are easily interpreted and amenable to daily practice via hematoxylin and eosin staining. We also consider the clinical advantages, limitations, and issues encountered while using these in routine clinical practice.

The applicability and utility of immunohistochemical biomarkers in bladder pathology

Urinary bladder specimens are frequently encountered in the daily practice of surgical pathologists. The spectrum of pathologic entities encountered in bladder specimens is extraordinarily broad, and in some instances, immunohistochemical stains are used to help characterize challenging bladder lesions. Cost-effective biomarker selection tailored to the differential diagnosis facilitates an accurate diagnosis. This comprehensive review is prepared as a reference guide for the use of immunohistochemistry to categorize primary and secondary bladder neoplasms and to evaluate metastatic cancers for possible bladder origin.

Human papillomavirus and urinary bladder cancer revisited

This review aims to present data on the association between human papillomavirus (HPV) and urinary bladder cancer (BC), especially of the subtype squamous cell carcinoma (SCC). Furthermore, the current data on the relation between p16, HPV, and BC are reviewed. PubMed was searched for 'Humans' [MESH] AND 'Papillomaviridae' [MESH] AND 'Urinary Bladder Neoplasms' [MESH], resulting in 157 potential articles. After profound reviewing, 18 articles were included in this review. Only original articles in English were included. A variable number of HPV genotypes in a small number of cases have been investigated in several studies with various methodology. HPV was present in 0-100% of cases depending on inclusion and exclusion criteria. SCC studies are mostly hampered by low number of cases whereas the few studies with a high number show a slightly higher prevalence of different HPV genotypes compared to pure urothelial carcinoma. Studies on p16 status in HPV positive cases are even more scarcely reported and show conflicting results. Most studies fail to prove clear-cut relevance of HPV in BC irrespectively of histological subtype. Negative p16 staining cannot rule out positive HPV status.

Squamous differentiation in patients with superficial bladder urothelial carcinoma is associated with high risk of recurrence and poor survival

Background

The independent prognostic role of squamous differentiation in pT1 bladder urothelial carcinoma has not been reported in previous studies. This article describes the impact of squamous differentiation on tumor recurrence and survival, and whether this histologic variant could indeed alter definitive treatment, based on single center-based retrospective data.

Methods

Totally, we retrieved (1)1449 histologically confirmed pT1 bladder urothelial carcinoma patients without histologic variants; (2)227 pT1 bladder urothelial carcinoma patients with squamous differentiation in our institution, from May 2004 to Oct 2015. The total amount of high/low grade urothelial carcinoma patients was 991/685 respectively. Transurethral resection of bladder tumor (TURBT) and intravesical chemotherapy were performed as initial treatments for all the patients. The clinical and pathological characteristics, treatment and survival outcomes were compared between squamous differentiation-positive and squamous differentiation-negative patients.

Results

In our study, 14% urothelial carcinoma patients were detected with squamous differentiation. The mean age of all the patients examined was 66.4, of whom 82% were males. The 5-year cancer specific survival rates were 69% for squamous differentiation-positive patients and 91% for squamous differentiation-negative patients (p < 0.001). Recurrence proved to be more common in squamous differentiation-positive patients than in negative patients. In the results of the univariate and multivariate Cox proportional hazard analysis, tumor size, lymphovascular invasion, recurrence and squamous differentiation were confirmed to be the prognostic factors associated with patients’ survival.

Conclusions

Squamous differentiation in pT1 bladder urothelial carcinoma is correlated to high risk of recurrence and poor prognosis as an independent prognostic factor. Radical cystectomy is essential for recurred high grade pT1 bladder urothelial carcinoma with squamous differentiation accompanied by lymphovascular invasion.

The expression of keratin 6 is regulated by the activation of the ERK1/2 pathway in arsenite transformed human urothelial cells

Urothelial cancers have an environmental etiological component, and previous studies from our laboratory have shown that arsenite (As⁺³) can cause the malignant transformation of the immortalized urothelial cells (UROtsa), leading to the expression of keratin 6 (KRT6). The expression of KRT6 in the parent UROtsa cells can be induced by the addition of epidermal growth factor (EGF). Tumors formed by these transformed cells have focal areas of squamous differentiation that express KRT6. The goal of this study was to investigate the mechanism involved in the upregulation of KRT6 in urothelial cancers and to validate that the As⁺³-transformed UROtsa cells are a model of urothelial cancer. The results obtained showed that the parent and the As⁺³-transformed UROtsa cells express EGFR which is phosphorylated with the addition of epidermal growth factor (EGF) resulting in an increased expression of KRT6. Inhibition of the extracellular-signal regulated kinases (ERK1/2) pathway by the addition of the mitogen-activated protein kinase kinase 1 (MEK1) and MEK2 kinase inhibitor U0126 resulted in a decrease in the phosphorylation of ERK1/2 and a reduced expression of KRT6. Immuno-histochemical analysis of the tumors generated by the As⁺³-transformed isolates expressed EGFR and tumors formed by two of the transformed isolates expressed the phosphorylated form of EGFR. These results show that the expression of KRT6 is regulated at least in part by the ERK1/2 pathway and that the As⁺³-transformed human urothelial cells have the potential to serve as a valid model to study urothelial carcinomas.

Informative gene selection and the direct classification of tumors based on relative simplicity

BACKGROUND

Selecting a parsimonious set of informative genes to build highly generalized performance classifier is the most important task for the analysis of tumor microarray expression data. Many existing gene pair evaluation methods cannot highlight diverse patterns of gene pairs only used one strategy of vertical comparison and horizontal comparison, while individual-gene-ranking method ignores redundancy and synergy among genes.

RESULTS

Here we proposed a novel score measure named relative simplicity (RS). We evaluated gene pairs according to integrating vertical comparison with horizontal comparison, finally built RS-based direct classifier (RS-based DC) based on a set of informative genes capable of binary discrimination with a paired votes strategy. Nine multi-class gene expression datasets involving human cancers were used to validate the performance of new method. Compared with the nine reference models, RS-based DC received the highest average independent test accuracy (91.40%), the best generalization performance and the smallest informative average gene number (20.56). Compared with the four reference feature selection methods, RS also received the highest average test accuracy in three classifiers (Naïve Bayes, k-Nearest Neighbor and Support Vector Machine), and only RS can improve the performance of SVM.

CONCLUSIONS

Diverse patterns of gene pairs could be highlighted more fully while integrating vertical comparison with horizontal comparison strategy. DC core classifier can effectively control over-fitting. RS-based feature selection method combined with DC classifier can lead to more robust selection of informative genes and classification accuracy.

Urothelial carcinoma with squamous differentiation--the pathologists׳ perspective

Squamous differentiation is the most common variant histology in urothelial carcinoma and may have effects on clinical outcome. Inconsistencies in reporting variant histologies in urothelial carcinoma are well documented. Immunohistochemical and molecular markers may help identify tumors with squamous differentiation beyond light microscopy.

Critical Role of the Neonatal Fc Receptor (FcRn) in the Pathogenic Action of Antimitochondrial Autoantibodies Synergizing with Anti-desmoglein Autoantibodies in Pemphigus Vulgaris

Pemphigus vulgaris (PV) is a life-long, potentially fatal IgG autoantibody-mediated blistering disease targeting mucocutaneous keratinocytes (KCs). PV patients develop pathogenic anti-desmoglein (Dsg) 3 ± 1 and antimitochondrial antibodies (AMA), but it remained unknown whether and how AMA enter KCs and why other cell types are not affected in PV. Therefore, we sought to elucidate mechanisms of cell entry, trafficking, and pathogenic action of AMA in PV. We found that PVIgGs associated with neonatal Fc receptor (FcRn) on the cell membrane, and the PVIgG-FcRn complexes entered KCs and reached mitochondria where they dissociated. The liberated AMA altered mitochondrial membrane potential, respiration, and ATP production and induced cytochrome c release, although the lack or inactivation of FcRn abolished the ability of PVIgG to reach and damage mitochondria and to cause detachment of KCs. The assays of mitochondrial functions and keratinocyte adhesion demonstrated that although the pathobiological effects of AMA on KCs are reversible, they become irreversible, leading to epidermal blistering (acantholysis), when AMA synergize with anti-Dsg antibodies. Thus, it appears that AMA enter a keratinocyte in a complex with FcRn, become liberated from the endosome in the cytosol, and are trafficked to the mitochondria, wherein they trigger pro-apoptotic events leading to shrinkage of basal KCs uniquely expressing FcRn in epidermis. During recovery, KCs extend their cytoplasmic aprons toward neighboring cells, but anti-Dsg antibodies prevent assembly of nascent desmosomes due to steric hindrance, thus rendering acantholysis irreversible. In conclusion, FcRn is a common acceptor protein for internalization of AMA and, perhaps, for PV autoantibodies to other intracellular antigens, and PV is a novel disease paradigm for investigating and elucidating the role of FcRn in this autoimmune disease and possibly other autoimmune diseases.

Oncogenic HRAS Activates Epithelial-to-Mesenchymal Transition and Confers Stemness to p53-Deficient Urothelial Cells to Drive Muscle Invasion of Basal Subtype Carcinomas

Muscle-invasive urothelial carcinomas of the bladder (MIUCB) exhibit frequent receptor tyrosine kinase alterations, but the precise nature of their contributions to tumor pathophysiology is unclear. Using mutant HRAS (HRAS*) as an oncogenic prototype, we obtained evidence in transgenic mice that RTK/RAS pathway activation in urothelial cells causes hyperplasia that neither progresses to frank carcinoma nor regresses to normal urothelium through a period of one year. This persistent hyperplastic state appeared to result from an equilibrium between promitogenic factors and compensatory tumor barriers in the p19-MDM2-p53-p21 axis and a prolonged G2 arrest. Conditional inactivation of p53 in urothelial cells of transgenic mice expressing HRAS* resulted in carcinoma in situ and basal-subtype MIUCB with focal squamous differentiation resembling the human counterpart. The transcriptome of microdissected MIUCB was enriched in genes that drive epithelial-to-mesenchymal transition, the upregulation of which is associated with urothelial cells expressing multiple progenitor/stem cell markers. Taken together, our results provide evidence for RTK/RAS pathway activation and p53 deficiency as a combinatorial theranostic biomarker that may inform the progression and treatment of urothelial carcinoma.