Published in Cancer Detection and Prevention 2000; 24(Supplement 1).

Expression patterns of hyaluronan receptors CD44 and RHAMM in transitional cell carcinoma of urinary bladder

H Li MD Phd, R Qi, T Wang MD, Q-zh Guo MD PhD, J Liu MD PhD

Div Molecular Biology, Shenyang Medical College, 110031 Shenyang, China,

AIM: Diffused local growth and distant metastasis are major risk factors for the patients suffering transitional cell carcinoma (TCC) of urinary bladder. Among metastasis- associated factors, interaction of hyaluronan acid (HA) and its receptors CD44 and RHAMM has been known to correlate with tumor dissemination. Our current study is aimed to further elucidate the clinical implication of CD44 expression for TCCs and the potential existence of other HA-mediated metastatic pathway in those cells. METHODS: A parallel evaluation of CD44 and RHAMM expression patterns in TCCs was performed using the combined methods of RT-PCR, RNA in situ hybridization, immunohistochemistry (IHC) and Western blot hybridization. RESULTS: Characterization of HA receptors CD44 and RHAMM in normal and cancerous bladder tissues (Table 1):
Table 1
Histology Cases (n) CD44 RHAMM
s/v v5 v6 v7 v8-v10 C C/M Total
None cancerous mucosa 10 7 7 7 0 1 2 0 2
Papillary cancer (pT1) 13 6 4 5 0 0 8 3 11
Transitional cancer (pT2) 18 6 5 6 3 0 7 9 16
TCC (pT3) 14 2 1 2 0 0 4 8 12
Adenocarcinoma 2 0 0 0 0 0 0 2 2
Western blot hybridization illustrated that RHAMM molecules produced by 2 non-cancerous urothelia showed molecular weights of 93-95kDa. Additional RHAMM isoforms ranging from 60kDa, 70-73kDa and 84kDa appeared as tumor progression. CONCLUSIONS: Expression of CD44 molecules harboring variant exons 6 and 5 may be a favorable prognostic indicator for TCC patients. Appearance of cell surface RHAMM isoforms is associated with TCC progression.

KEY WORDS: metastasis, transitional cell carcinoma, hyaluronan acid.

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Paper presented at the International Symposium on Impact of Biotechnology on Cancer Diagnostic & Prognostic Indicators; Geneva, Switzerland; October 28 - 31, 2000; in the section on prognostic markers.