Proteome characterization of a human urothelial cell line resistant to the bladder carcinogen 4-aminobiphenyl

Identification and bioinformatics analysis of miRNAs associated with human muscle invasive bladder cancer

Accumulated evidence has indicated that micro (mi)RNAs play vital roles in the occurrence and development of human muscle invasive bladder cancer (MIBC), however, little is known about the miRNAs' regulatory networks. In the present study, the authors aimed to use bioinformatics analysis to identify the key miRNAs and potential target genes, as well as studying the underlying mechanisms for MIBC. They collected several human MIBC tissues to generate a miRNA expression analysis by microarray analysis comparing with normal bladder tissues, identifying 104 differentially expressed miRNAs (102 were downregulated and 2 were upregulated) and predicted 11,884 putative target genes of the dysregulated miRNAs. To understand the function of dysregulated miRNAs in the development of MIBC, networks among miRNAs and genes, gene ontologies and pathways were built. The subsequent bioinformatics analysis indicated that the mitogen-associated protein kinase (MAPK) signaling pathway, apoptosis and pathways in cancer and the cell cycle, were significantly enriched Overall, these results provided comprehensive information on the biological function of dysregulated miRNAs in the development of MIBC. The identification of miRNAs and their putative targets may offer new diagnostic and therapeutic strategies for human muscle invasive bladder cancer.

Infiltrating neutrophils increase bladder cancer cell invasion via modulation of androgen receptor (AR)/MMP13 signals

Early studies indicated that several inflammatory immune cells, including macrophages, mast cells, B and T cells in the tumor microenvironment, might influence cancer progression. Here we found that bladder cancer (BCa) cells could recruit more neutrophils than normal bladder cells. The consequences of recruiting more neutrophils might then increase BCa cell invasion via up-regulating androgen receptor (AR) signals. Mechanism dissection revealed infiltrating neutrophils could up-regulate AR signals via either increased AR mRNA/protein expression or increased AR transactivation. The increased AR signals might then enhance BCa cell invasion via increasing MMP13 expression. Together, these results might provide us a new potential therapeutic approach to better battle BCa metastasis via targeting the newly identified signaling from infiltrating neutrophils to BCa through AR to MMP13 signals.

Identification of proteins differentially expressed in adriamycin-resistant (pumc-91/ADM) and parental (pumc-91) human bladder cancer cell lines by proteome analysis

PURPOSE

Resistance to chemotherapy drugs remains a difficult problem in bladder cancer treatment. Protein expression is an important factor underlying multidrug resistance (MDR) in bladder cancer. The aim of the study was to explore differentially expressed proteins responsible for MDR between an adriamycin-resistant human bladder cancer cell line (pumc-91/ADM) and its parental cell line (pumc-91).

METHODS

Two-dimensional gel electrophoresis (2-DE) combining image analysis was used to screen the differentially expressed protein spots between the pumc-91/ADM and pumc-91 cell lines. Then, the protein spots were identified using MALDI-TOF/TOF mass spectrometry. Among the identified proteins, annexin A2 (ANXA2) and nucleophosmin (NPM1) were then further verified using RT-PCR and Western blot analysis.

RESULTS

A total of 30 proteins, including 19 up-regulated and 11 down-regulated proteins, were successfully identified in pumc-91/ADM. According to their different functions, these 30 proteins were classified into 12 categories. Annexin A2 (ANXA2) and nucleophosmin (NPM1) were up-regulated in pumc-91/ADM compared with pumc-91.

CONCLUSION

The proteins identified may have an important clinical significance in MDR, and ANXA2 and NPM1 may take part in mechanism of MDR in bladder cancer.

Up-regulation of annexin A2 in cholangiocarcinoma caused by Opisthorchis viverrini and its implication as a prognostic marker

Cholangiocarcinoma (CCA), or cancer of the bile ducts, is primarily associated with infection with the liver fluke Opisthorchis viverrini in northeast Thailand. The disease is associated with late presentation, poses challenges for diagnosis and has a high mortality rate--features that highlight the need for tumor markers. At present, there are no specific tumor markers that can indicate the early stages and status of CCA. Proteomic analysis of the proteins expressed on the surface of tumor cells is particularly difficult since proteome-wide analysis of surface membrane proteins has thus far been hampered by the lack of effective strategies to profile hydrophobic membrane proteins. In this study, a sequential protein extraction was utilized to overcome this problem. Membrane protein was extracted from four CCA cell lines with different tumor forming capabilities. The non-tumor H69 biliary cell line was used as a control. Two-dimensional-PAGE followed by MALDI-TOF-MS was used to identify differentially expressed proteins. Among 20 up-regulated membrane proteins identified in the CCA cell lines was ANXA2, a participant in tumor invasion and metastasis in other cancers. Accordingly, ANXA2 was verified in human subjects by probing, using a commercial anti-mouse monoclonal antibody and a tissue microarray of CCA (301 diagnosed cases), where it was found to associate with one of several tumor progression stages as reflected by lymphatic invasion (P=0.014) and metastasis (P=0.026). Patients with high expression of ANXA2 had a significantly shorter survival time (P=0.011). ANXA2 expression in tumors may be useful for predicting the poor outcome of CCA patients.