Expresión inmunohistoquímica de p53, p21, p16 y Ciclina D1 en el cáncer de vejiga superficial. Estudio en un soporte de tissue microarray

Companied P16 genetic and protein status together providing useful information on the clinical outcome of urinary bladder cancer

SPEC P16/CEN3/7/17 Probe fluorescence-in-situ-hybridization (FISH) has become the most sensitive method in indentifying the urothelial tumors and loss of P16 has often been identified in low-grade urothelial lesions; however, little is known about the significations of other P16 genetic status (normal and amplification) in bladder cancer.We detected P16 gene status by FISH in 259 urine samples and divided these samples into 3 groups: 1, normal P16; 2, loss of P16; and 3, amplified P16. Meanwhile, p16 protein expression was measured by immunocytochemistry and we characterized the clinicopathologic features of cases with P16 gene status.Loss of P16 occurred in 26.2%, P16 amplification occurred in 41.3% and P16 gene normal occurred in 32.4% of all cases. P16 genetic status was significantly associated with tumor grade and primary tumor status (P = .008 and .017), but not with pathological tumor stage, overall survival, and p16 protein expression. However, P16 gene amplification accompanied protein high-expression has shorter overall survival compared with the overall patients (P = .023), and P16 gene loss accompanied loss of protein also had the tendency to predict bad prognosis (P = .067).Studies show that the genetic status of P16 has a close relation with the stages of bladder cancer. Loss of P16 is associated with low-grade urothelial malignancy while amplified P16 donotes high-grade. Neither P16 gene status nor p16 protein expression alone is an independent predictor of urothelial bladder carcinoma, but combine gene and protein status together providing useful information on the clinical outcome of these patients.

Roles of SPARC in urothelial carcinogenesis, progression and metastasis

Secreted Protein Acidic and Rich in Cysteine (SPARC) is a matricellular glycoprotein that is implicated in myriad physiological and pathological conditions characterized by extensive remodeling and plasticity. The functions and disease association of SPARC in cancer is being increasingly appreciated as it plays multi-faceted contextual roles depending on the cancer type, cell of origin and the unique cancer milieu at both primary and metastatic sites. Herein we will review our current knowledge of the role of SPARC in the multistep cascades of urinary bladder carcinogenesis, progression and metastasis from preclinical models and clinical data and shine the light on its prognostic and therapeutic potentials.

Prognostic and Clinicopathological Significance of Downregulated p16 Expression in Patients with Bladder Cancer: A Systematic Review and Meta-Analysis

p16, encoded by the CDKN2A gene, is a tumor suppressor that has been widely studied in cancer research. However, the relationship of p16 with prognostic and clinicopathological parameters in patients with bladder cancer remains unclear. Data inclusion criteria were articles reporting on the relationship between p16 expression and the prognosis or clinicopathology in patients with bladder cancer. Meta-analyses were performed with Stata software. Hazard ratios (HRs) or odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated to evaluate the relative risks. The source of heterogeneity was analyzed by subgroup analysis. A total of 37 studies with 2246 cases were included and analyzed. The results identified an important link between downregulated p16 expression and poor prognosis in patients with bladder cancer in terms of recurrence-free survival (RFS), overall survival (OS), progression-free survival (PFS), and some clinicopathological parameters including clinical staging, pathological degree, and lymph node metastasis. Subgroup analysis also showed that low p16 expression could function as a warning sign for RFS and PFS in patients with early-stage (Ta–T1) bladder cancer. In conclusion, p16 might play an essential role in the deterioration of bladder cancer and could serve as a biomarker for the prediction for patients' progression and prognosis.

Spotlight on differentially expressed genes in urinary bladder cancer

INTRODUCTION

We previously identified common differentially expressed (DE) genes in bladder cancer (BC). In the present study we analyzed in depth, the expression of several groups of these DE genes.

MATERIALS AND METHODS

Samples from 30 human BCs and their adjacent normal tissues were analyzed by whole genome cDNA microarrays, qRT-PCR and Western blotting. Our attention was focused on cell-cycle control and DNA damage repair genes, genes related to apoptosis, signal transduction, angiogenesis, as well as cellular proliferation, invasion and metastasis. Four publicly available GEO Datasets were further analyzed, and the expression data of the genes of interest (GOIs) were compared to those of the present study. The relationship among the GOI was also investigated. GO and KEGG molecular pathway analysis was performed to identify possible enrichment of genes with specific biological themes.

RESULTS

Unsupervised cluster analysis of DNA microarray data revealed a clear distinction in BC vs. control samples and low vs. high grade tumors. Genes with at least 2-fold differential expression in BC vs. controls, as well as in non-muscle invasive vs. muscle invasive tumors and in low vs. high grade tumors, were identified and ranked. Specific attention was paid to the changes in osteopontin (OPN, SPP1) expression, due to its multiple biological functions. Similarly, genes exhibiting equal or low expression in BC vs. the controls were scored. Significant pair-wise correlations in gene expression were scored. GO analysis revealed the multi-facet character of the GOIs, since they participate in a variety of mechanisms, including cell proliferation, cell death, metabolism, cell shape, and cytoskeletal re-organization. KEGG analysis revealed that the most significant pathway was that of Bladder Cancer (p = 1.5×10(-31)).

CONCLUSIONS

The present work adds to the current knowledge on molecular signature identification of BC. Such works should progress in order to gain more insight into disease molecular mechanisms.

Scoring of p16(INK4a) immunohistochemistry based on independent nuclear staining alone can sufficiently distinguish between endocervical and endometrial adenocarcinomas in a tissue microarray study

Endocervical adenocarcinomas and endometrial adenocarcinomas are malignancies that affect uterus; however, their biological behaviors are quite different. This distinction has clinical significance, because the appropriate therapy may depend on the site of tumor origin. The purpose of this study is to evaluate four different scoring methods of p16(INK4a) immunohistochemical staining in distinguishing between primary endocervical adenocarcinomas and endometrial adenocarcinomas from limited sizes of tissue specimens. A tissue microarray was constructed using formalin-fixed, paraffin-embedded tissue from hysterectomy specimens, including 14 endocervical adenocarcinomas and 21 endometrial adenocarcinomas. Tissue array sections were immunostained with a commercially available antibody of p16(INK4a). Avidin-biotin complex method was used for antigens visualization. The staining intensity and area extent of the immunohistochemistry was evaluated using the semiquantitative scoring system. Of the four scoring methods for p16(INK4a) expression, Method Nucleus, Method Dominant Cytoplasm or Nucleus, and Method Mean of Cytoplasm plus Nucleus showed significant (P values <0.05), but Method Cytoplasm did not show significant (P=0.432), frequency distinction between endocervical adenocarcinomas and endometrial adenocarcinomas. In addition, Method Mean of Cytoplasm plus Nucleus had the highest overall accuracy rate (80%) for diagnostic distinction among these four score-counting methods. According to the data in this tissue microarray study, Method Nucleus is the most convenient and efficient method to distinguish between endocervical adenocarcinomas and endometrial adenocarcinomas. Although Method Dominant Cytoplasm or Nucleus as well as Method Mean of Cytoplasm plus Nucleus also revealed statistically significant results, they are relatively more inconvenient due to complicated score calculating means on the basis of mixed cytoplasmic and nuclear p16(INK4a) expressions. Method Cytoplasm is of no use in the diagnostic distinction between endocervical adenocarcinomas and endometrial adenocarcinomas.

Scoring mechanisms of p16INK4a immunohistochemistry based on either independent nucleic stain or mixed cytoplasmic with nucleic expression can significantly signal to distinguish between endocervical and endometrial adenocarcinomas in a tissue microarray study

Background

Endocervical adenocarcinomas (ECAs) and endometrial adenocarcinomas (EMAs) are malignancies that affect uterus; however, their biological behaviors are quite different. This distinction has clinical significance, because the appropriate therapy may depend on the site of tumor origin. The purpose of this study is to evaluate 3 different scoring mechanisms of p16^INK4a immunohistochemical (IHC) staining in distinguishing between primary ECAs and EMAs.

Methods

A tissue microarray (TMA) was constructed using formalin-fixed, paraffin-embedded tissue from hysterectomy specimens, including 14 ECAs and 24 EMAs. Tissue array sections were immunostained with a commercially available antibody of p16^INK4a. Avidin-biotin complex (ABC) method was used for antigens visualization. The staining intensity and area extent of the IHC reactions was evaluated using the semi-quantitative scoring system. The 3 scoring methods were defined on the bases of the following: (1) independent cytoplasmic staining alone (Method C), (2) independent nucleic staining alone (Method N), and (3) mean of the sum of cytoplasmic score plus nucleic score (Method Mean of C plus N).

Results

Of the 3 scoring mechanisms for p16^INK4a expression, Method N and Method Mean of C plus N showed significant (p-values < 0.05), but Method C showed non-significant (p = 0.245) frequency differences between ECAs and EMAs. In addition, Method Mean of C plus N had the highest overall accuracy rate (81.6%) for diagnostic distinction among these 3 scoring methods.

Conclusion

According to the data characteristics and test effectiveness in this study, Method N and Method Mean of C plus N can significantly signal to distinguish between ECAs and EMAs; while Method C cannot do. Method Mean of C plus N is the most promising and favorable means among the three scoring mechanisms.

Notes on the tumorigenesis of bladder urothelioma

Bladder urothelioma is a common and increasingly frequent tumor, which most of the times involves initially the bladder mucosa only. Urotheliomas can be superficial, with low malignant potential despite their high relapsing activity, and highly aggressive ab initio. A series of events are known to influence urothelioma genesis, growth, cell interactions and apoptosis. Some initial constant changes involving chromosome 9 occur in the urothelium, whereas the 20–30 % of cases also show an alteration on chromosome 20, which is likely to result in marked biological aggressiveness. The transformation of normal urothelium into hyperplastic, and then neoplastic, urothelium is secondary to a wide range of molecular changes, which are here summarized.