Far from resolved: Stromal cell-based iTRAQ research of muscle-invasive bladder cancer regarding heterogeneity

Abstract

The aim of the present study was to globally characterize the cancer stroma expression profile of muscle-invasive bladder cancer in different metastatic risk groups and to discuss the decisive role of biological pathway change in cancer heterogeneity. Laser capture microdissection was employed to harvest purified muscle-invasive bladder cancer stromal cells derived from 30 clinical samples deriving from 3 different metastatic risk groups. Isobaric tags for relative and absolute quantitation (iTRAQ) and two-dimensional liquid chromatography tandem mass spectrometry (2D LC-MS/MS) were used to identify the differentially expressed proteins. Subsequently, the differentially expressed proteins were further analyzed by bioinformatics tools. After completing the above tasks, the proteins of interest were further compared with the published litterature. We identified 1,049 differentially expressed proteins by paired comparison (high risk vs. median, low risk and normal groups; median risk vs. low risk and normal groups, low risk vs. normal group; a total of 6 comparisons). A total of 510,549,548 proteins as significantly altered (ratio fold-change≥1.5 or ≤0.667 between the metastatic potential risk group and the normal group) were presented in the low/median/high metastatic risk group, respectively. Pathway analysis revealed that the differentially expressed proteins were mainly located in the Kyoto Encyclopedia of Genes and Genomes pathways, including focal adhesion pathway, systemic lupus erythematosus pathway and ECM-receptor interaction pathway. In addition, several proteins such as EXOC4, MYH10 and MMP-9 may serve as candidate biomarkers of muscle-invasive bladder cancer. Our study confirmed that stromal cells, an important part of the cancer tissue, are pivotal for regulating the heterogeneity of cancer. Common changes in biological pathways determined the malignant phenotype of muscle-invasive bladder cancer, and biomarker discovery should take into account both neoplastic cells and their corresponding stromata.

Developing proteomic biomarkers for bladder cancer: towards clinical application

“…MIBC tumour sections were first compared to adjacent normal lesions, 89 and, in an independent approach, stromal cells from MIBC were analysed. 90 The authors reported an upregulation of MMP9, exocyst complex component 4 and myosin-10 and suggested these proteins should be further verified as MIBC-specific protein biomarkers. 90 Prognostic or predictive tissue biomarkers Immunohistochemistry has been widely used to characterize tissue protein biomarkers and to identify potential prognostic or predictive value, thus enabling improved assessment of the risk of disease recurrence and/or progression.…”

“…90 The authors reported an upregulation of MMP9, exocyst complex component 4 and myosin-10 and suggested these proteins should be further verified as MIBC-specific protein biomarkers. 90 Prognostic or predictive tissue biomarkers Immunohistochemistry has been widely used to characterize tissue protein biomarkers and to identify potential prognostic or predictive value, thus enabling improved assessment of the risk of disease recurrence and/or progression. The same principle also applies to prediction of treatment responses to intravesical BCG instillations in patients with NMIBC and treatment responses to radiotherapy and/or adjuvant or neoadjuvant chemo therapy in patients with locally advanced MIBC.…”

“…Moreover, low DDX39 expression indicated by weaker antibody staining was associated with significantly more rapid disease progression (P = 0.0083), based on follow-up data from 105 patients. 84 A range of studies [85][86][87][88][89][90] used LCM to specifically extract tumour-associated stroma and tissue samples from normal urothelium in an attempt to characterize bladder tumours compared with their adjacent urothelium 85 and the adjacent stromal cells. [86][87][88] In a study of superficial bladder tumours, 2D liquid chromatography followed by tandem mass spectrometry was used to investigate four pairs of superficial tumour cells and their adjacent normal urothelium.…”

A bladder cancer microenvironment simulation system based on a microfluidic co-culture model

“…[ 23 ] The dynamic interaction between microenvironment and neoplastic cells has been correlated to VM formation. [ 11 , 19 ] The vasculogenic mimicry phenomenon is significant in bladder cancer microenvironment simulation.…”

Microfluidic modelling of the tumor microenvironment for anti-cancer drug development

“…Many different non-neoplastic cells exist in the tumor microenvironment and interact with tumor cells. Endothelial cells, fibroblasts, and immune cells are the three main cell types which appear in most cancers and are vital components in enhancing the drug resistance of tumors [103,[114][115][116][117][118][119][120]. Endothelial cells are one of the major components of blood vessels and play an important role in tumor angiogenesis [121].…”