p63 expression defines a lethal subset of muscle-invasive bladder cancers

Background

p63 is a member of the p53 family that has been implicated in maintenance of epithelial stem cell compartments. Previous studies demonstrated that p63 is downregulated in muscle-invasive bladder cancers, but the relationship between p63 expression and survival is not clear.

Methodology/Principal Findings

We used real-time PCR to characterize p63 expression and several genes implicated in epithelial-to-mesenchymal transition (EMT) in human bladder cancer cell lines (n = 15) and primary tumors (n = 101). We correlated tumor marker expression with stage, disease-specific (DSS), and overall survival (OS). Expression of E-cadherin and p63 correlated directly with one another and inversely with expression of the mesenchymal markers Zeb-1, Zeb-2, and vimentin. Non-muscle-invasive (Ta and T1) bladder cancers uniformly expressed high levels of E-cadherin and p63 and low levels of the mesenchymal markers. Interestingly, a subset of muscle-invasive (T2–T4) tumors maintained high levels of E-cadherin and p63 expression. As expected, there was a strongly significant correlation between EMT marker expression and muscle invasion (p<0.0001). However, OS was shorter in patients with muscle-invasive tumors that retained p63 (p = 0.007).

Conclusions/Significance

Our data confirm that molecular markers of EMT are elevated in muscle-invasive bladder cancers, but interestingly, retention of the “epithelial” marker p63 in muscle-invasive tumors is associated with a worse outcome.     

乳腺癌蛋白质组研究进展

乳腺癌是发生在乳房腺上皮组织的恶性肿瘤,其发病率占女性恶性肿瘤首位。近年来,蛋白质组研究广泛深入乳腺癌发病机理、临床早期诊断和治疗等各个方面。本文比较系统地综述了乳腺蛋白质组研究的样品处理、研究技术和研究成果。     

Molecular pathogenesis of non muscle-invasive bladder cancer: implications for novel targeted therapies

Approximately 70% to 80% of patients with urothelial carcinomas of the bladder are initially diagnosed with non-muscle invasive disease. Superficial, non-muscle invasive bladder cancers (NMIBCs) are managed with cystoscopic transurethral resection of all visible lesions followed by intravesical chemotherapy and/or immunotherapy. Despite this treatment, up to 70% of these tumors will recur within five years and 15% will ultimately progress to muscle-invasive disease, suggesting that novel therapeutic strategies are necessary. Recent studies have greatly advanced our understanding of urothelial carcinogenesis and have highlighted the distinct molecular pathogenesis of NMIBCs versus muscle-invasive bladder tumors. It is now clear that diverse genetic and epigenetic events are driving the oncogenesis of NMIBCs, thereby attesting to their potential as therapeutic targets for these tumors. This article reviews the molecular pathogenesis of NMIBCs, discusses recently completed and ongoing clinical trials and anticipates the future direction of molecular targeted agents in this disease.     

Bladder preservation by concurrent chemoradiation for muscle-invasive bladder cancer: Applicability in low-income countries

Background

Radical cystectomy is the standard treatment for patients with muscle-invasive urinary bladder cancer; however, is associated with major treatment – related morbidity. Furthermore, a significant proportion of patients are deemed unsuitable for surgery due to inoperability, advanced age, and/or comorbid conditions. As such, several groups have explored effectiveness of less radical therapeutic strategies that aim at bladder preservation. Nonetheless, there is scarcity of reports assessing the applicability of urinary bladder-sparing outside developed countries.

Aim

Determine the achievable outcomes for patients with muscle-invasive urinary bladder cancer treated via bladder-sparing techniques in a low income country.

Materials and methods

Fourteen consecutive patients with a diagnosis of muscle-invasive urinary bladder cancer (clinical stage; T2-3N0M0) were treated via a bladder-sparing approach at King Hussein Cancer Center (Amman, Jordan) between 2005 and 2009. Records were electronically retrieved and retrospectively analyzed and included 11 males and 3 females from 41 to 74 years of age (median age, 61). Initial therapy consisted of trans-urethral resection of bladder tumor (TURBT) followed by induction chemotherapy then irradiation (4500cGy) with concurrent platinum-based chemotherapy. Urological evaluation directed additional therapy in a proportion of patients with irradiation (up to 6400 cGy) in patients who achieved CR.

Results

Eleven patients were evaluable for pathological response at time of re-staging; of whom 8 (73%) achieved CR and 3 (27%) achieved partial response (PR). In all but one patient; combined-modality treatment was well tolerated. After a median follow-up of 18.5 months (range, 3–48 months); 5 of 8 (62.5%) patients with CR were alive.

Conclusions

Bladder-sparing strategies via concurrent chemoradiation for muscle-invasive bladder cancer results in an acceptable rate of complete pathological response with adequate short-term outcomes. This approach appears applicable in low-income countries.     

Stromal gene expression predicts clinical outcome in breast cancer

Although it is increasingly evident that cancer is influenced by signals emanating from tumor stroma, little is known regarding how changes in stromal gene expression affect epithelial tumor progression. We used laser capture microdissection to compare gene expression profiles of tumor stroma from 53 primary breast tumors and derived signatures strongly associated with clinical outcome. We present a new stroma-derived prognostic predictor (SDPP) that stratifies disease outcome independently of standard clinical prognostic factors and published expression-based predictors. The SDPP predicts outcome in several published whole tumor-derived expression data sets, identifies poor-outcome individuals from multiple clinical subtypes, including lymph node-negative tumors, and shows increased accuracy with respect to previously published predictors, especially for HER2-positive tumors. Prognostic power increases substantially when the predictor is combined with existing outcome predictors. Genes represented in the SDPP reveal the strong prognostic capacity of differential immune responses as well as angiogenic and hypoxic responses, highlighting the importance of stromal biology in tumor progression.     

Green fluorescent protein expression triggers proteome changes in breast cancer cells

Green fluorescent protein (GFP) is the most commonly used reporter of expression in cell biology despite evidence that it affects the cell physiology. The molecular mechanism of GFP-associated modifications has been largely unexplored. In this paper we investigated the proteome modifications following stable expression of GFP in breast cancer cells (MDA-MB-231). A combination of three different proteome analysis methods (2-DE, iTRAQ, label-free) was used to maximise proteome coverage. We found that GFP expression induces changes in expression of proteins that are associated with protein folding, cytoskeletal organisation and cellular immune response. In view of these findings, the use of GFP as a cell reporter should be carefully monitored.     

模式植物蛋白质组研究进展

蛋白质组学是后基因组时代研究的热点,而植物蛋白质组是此研究领域的一块奇葩。这主要归功于模式植物蛋白质组的成就。本文综述了模式植物拟南芥、大豆、水稻、大麦、小麦、玉米蛋白质组的研究进展,并简要介绍了本实验室的工作.最后展望了植物蛋白质组学今后的发展前景。     

The secreted proteome profile of developing Dictyostelium discoideum cells

Dictyostelium discoideum is a unicellular eukaryote that, when starved, aggregates to form multicellular structures. In this report, we identified the proteins secreted by developing Dictyostelium cells using MS‐based proteomics. A total of 349 different secreted proteins were identified, indicating that at least 2.6% of the 13 600 predicted proteins in the Dictyostelium genome are secreted. Gene ontology analysis suggests that many of the secreted proteins are involved in protein and carbohydrate metabolism, and proteolysis.     

Web-accessible proteome databases for microbial research

The analysis of proteomes of biological organisms represents a major challenge of the post-genome era. Classical proteomics combines two-dimensional electrophoresis (2-DE) and mass spectrometry (MS) for the identification of proteins. Novel technologies such as isotope coded affinity tag (ICAT)-liquid chromatography/mass spectrometry (LC/MS) open new insights into protein alterations. The vast amount and diverse types of proteomic data require adequate web-accessible computational and database technologies for storage, integration, dissemination, analysis and visualization. A proteome database system (http://www.mpiib-berlin.mpg.de/2D-PAGE) for microbial research has been constructed which integrates 2-DE/MS, ICAT-LC/MS and functional classification data of proteins with genomic, metabolic and other biological knowledge sources. The two-dimensional polyacrylamide gel electrophoresis database delivers experimental data on microbial proteins including mass spectra for the validation of protein identification. The ICAT-LC/MS database comprises experimental data for protein alterations of mycobacterial strains BCG vs. H37Rv. By formulating complex queries within a functional protein classification database "FUNC_CLASS" for Mycobacterium tuberculosis and Helicobacter pylori the researcher can gather precise information on genes, proteins, protein classes and metabolic pathways. The use of the R language in the database architecture allows high-level data analysis and visualization to be performed "on-the-fly". The database system is centrally administrated, and investigators without specific bioinformatic competence in database construction can submit their data. The database system also serves as a template for a prototype of a European Proteome Database of Pathogenic Bacteria. Currently, the database system includes proteome information for six strains of microorganisms.     

Lens proteome map and alpha-crystallin profile of the catfish Rita rita

Crystallins are a diverse group of proteins that constitute nearly 90% of the total soluble proteins of the vertebrate eye lens and these tightly packed crystallins are responsible for transparency of the lens. These proteins have been studied in different model and non-model species for understanding the modifications they undergo with ageing that lead to cataract, a disease of protein aggregation. In the present investigation, we studied the lens crystallin profile of the tropical freshwater catfish Rita rita. Profiles of lens crystallins were analyzed and crystallin proteome maps of Rita rita were generated for the first time. alphaA-crystallins, member of the alpha-crystallin family, which are molecular chaperons and play crucial role in maintaining lens transparency were identified by 1- and 2-D immunoblot analysis with anti-alphaA-crystallin antibody. Two protein bands of 19-20 kDa were identified as alphaA-crystallins on 1-D immunoblots and these bands separated into 10 discrete spots on 2-D immunoblot. However, anti-alphaB-crystallin and antiphospho-alphaB-crystallin antibodies were not able to detect any immunoreactive bands on 1- and 2-D immunoblots, indicating alphaB-crystallin was either absent or present in extremely low concentration in Rita rita lens. Thus, Rita rita alpha-crystallins are more like that of the catfish Clarias batrachus and the mammal kangaroo in its alphaA- and alphaB-crystallin content (contain low amount from 5-9% of alphaB-crystallin) and unlike the dogfish, zebrafish, human, bovine and mouse alpha-crystallins (contain higher amount of alphaB-crystallin from 25% in mouse and bovine to 85% in dogfish). Results of the present study can be the baseline information for stimulating further investigation on Rita rita lens crystallins for comparative lens proteomics. Comparing and contrasting the alpha-crystallins of the dogfish and Rita rita may provide valuable information on the functional attributes of alphaA- and alphaB-isoforms, as they are at the two extremes in terms of alphaA-and alphaB-crystallin content.     

Stromal biology of pancreatic cancer

The genetic paradigm of cancer, focused largely on sequential molecular aberrations and associated biological impact in the neoplastic cell compartment of malignant tumors, has dominated our view of cancer pathogenesis. For the most part, this conceptualization has overlooked the dynamic and complex contributions of the surrounding microenvironment comprised of non-tumor cells (stroma) that may resist, react to, and/or foster tumor development. Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease in which a prominent tumor stroma compartment is a defining characteristic. Indeed, the bulk of PDAC tumor volume consists of non-neoplastic fibroblastic, vascular, and inflammatory cells surrounded by immense quantities of extracellular matrix, far exceeding that found in most other tumor types. Remarkably, little is known about the composition and physiology of the PDAC tumor microenvironment, in particular, the role of stroma in tumor initiation and progression. This review attempts to define key challenges, opportunities and state-of-knowledge relating to the PDAC microenvironment research with an emphasis on how inflammatory processes and key cancer pathways may shape the ontogeny of the tumor stroma. Such knowledge may be used to understand the evolution and biology of this lethal cancer and may convert these insights into new points of therapeutic intervention.