Bladder cancer (BlCa) is the second most common genitourinary cancer, affecting both men and women. Most (70%) cases present at the superficial stage; 20% of these recur with muscle-invasive disease. Major genetic alterations associated with BlCa include: loss/gain in expression or mutations in Retinoblastoma (RB) gene, human epidermal growth factor receptors (HERs), H-ras, p53 and FGFR3. Only p53 mutations are well correlated with invasive BlCa; other changes show variable correlations with disease status. To understand the progression of BlCa, a model of nine human BlCa cell sublines derived from a single parent but differing in in vivo characteristics, has been developed previously. These cells represent a heterogenous population from a single tumour and a model of different stages of BlCa progression, from non-tumourigenic to invasive. Two sublines were selected for further investigation: C3 (non-tumourigenic) and B8 (invasive). These were transfected with green (C3-GSP-2) and red fluorescent reporters (B8-RSP-gck) respectively to investigate the effects of their co-injection in vivo, specifically, promotion of C3 tumour growth by B8 cells. Surprisingly, B8 tumour growth was inhibited by C3 cells in vivo at different cell numbers and proportions of cells injected. Microarray analysis of C3 and B8 cells revealed differential expression of 1367 genes with dramatic differences in the transforming growth factor-?? and integrin-mediated pathways. Gene expression of BMP2, INHBB, FST, NOG, ID4 and TGF- ??1, in the TGF- ?? pathway was further analysed with qRT-PCR in all nine sublines. Expression of BMP2 was significantly related to tumourigenic potential (p=0.0238, Mann-Whitney) and INHBB to invasive ability (p=0.0476, Mann-Whitney). The BlCa model did not include a metastatic component. To broaden the model, cell lines were established from an invaded lymph-node (B8-RSP-LN) and a bone-metastasis (B8-RSP-BN) after subcutaneous and intra-cardiac injection of B8-RSP-gck cells. No significant differences were observed in the migratory capability and anchorage-independent colony formation of these metastatic cells compared with B8 cells. Evaluation of expression of the panel of TGF-beta genes (BMP2, INHBB, FST, NOG, ID4 and TGF- ??1) and metastasis-related genes (MMP9, MMP2 and KAI1) indicated that expression of BMP2, FST, ID4 and MMP9 was decreased or lost in the metastatic sublines.
| Identifer | oai:union.ndltd.org:ADTP/225546 |
| Date | January 2009 |
| Creators | Hung, Tzong Tyng, Clinical School - Prince of Wales Hospital, Faculty of Medicine, UNSW |
| Publisher | Awarded by:University of New South Wales. |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright Hung Tzong Tyng., http://unsworks.unsw.edu.au/copyright |
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