Hypoxia-inducible factor and mammalian target of rapamycin pathway markers in urothelial carcinoma of the bladder: Possible therapeutic implications Journal Article


Authors: Tickoo, S. K.; Milowsky, M. I.; Dhar, N.; Dudas, M. E.; Gallagher, D. J.; Al-Ahmadie, H.; Gopalan, A.; Fine, S. W.; Ishill, N.; Bajorin, D. F.; Reuter, V. E.
Article Title: Hypoxia-inducible factor and mammalian target of rapamycin pathway markers in urothelial carcinoma of the bladder: Possible therapeutic implications
Abstract: What's known on the subject? and What does the study add? The hypoxia-inducible factor (HIF) and mammalian target of rapamycin (mTOR) pathways are important in tumorigenesis and novel agents targeting these respective pathways have shown promising activity in several malignancies. The current study demonstrates the expression of HIF and mTOR related pathway markers in urothelial carcinoma providing a rationale for clinical trials evaluating agents targeting these pathways. OBJECTIVE To investigate the rationale for using targeted therapies against hypoxia-inducible factor (HIF) and mammalian target of rapamycin (mTOR) pathways in urothelial carcinoma of the bladder, by studying the immunohistochemical expression of molecules of these pathways in urothelial carcinoma, as recent pre-clinical studies and clinical trials have shown the potential utility of such targeted therapies. PATIENTS AND METHODS Immunohistochemical stains were performed on a tissue microarray prepared from 92 cases of ≥ pT2 urothelial (transitional cell) carcinoma of bladder, using antibodies against HIF-1α and VEGF-R2, and phospho-S6 and phospho-4E BP1, molecules of HIF and activated mTOR pathways, respectively. Immunoreactivity was graded from 0 to 3+ (0, 0-5%; 1+, 6-25%; 2+, 26-50%; 3+, > 50% tumour cells positive). RESULTS In all, 58, 34, 35 and 17% of the tumours showed grade 2-3+ expression of phospho-4E BP1, phospho-S6, HIF-1α and VEGF-R2, respectively. Moderate correlation for immunoreactivity was observed between molecules within the same pathway [(phospho-4E BP1 with phospho-S6 (rho = 0.411), and HIF-1α with VEGF-R2 (rho = 0.265)], but not between molecules across pathways. CONCLUSIONS Urothelial carcinomas of the bladder express molecules of the HIF and mTOR pathways, providing a rationale for clinical trials evaluating agents targeting these pathways. Correlation between molecules within the same pathway, and not across pathways, suggests that investigating the usefulness of a specific targeted agent might benefit from pre-treatment evaluation of pathway marker expression. © 2010 BJU International.
Keywords: immunohistochemistry; controlled study; human tissue; protein expression; cancer staging; vasculotropin receptor 2; cancer invasion; mammalian target of rapamycin; tumor cell; initiation factor 4e binding protein 1; bladder carcinoma; tumor vascularization; hypoxia inducible factor 1alpha; transitional cell carcinoma; protein s6; hypoxia-inducible factor
Journal Title: BJU International
Volume: 107
Issue: 5
ISSN: 1464-4096
Publisher: Wiley Blackwell  
Date Published: 2011-03-01
Start Page: 844
End Page: 849
Language: English
DOI: 10.1111/j.1464-410X.2010.09517.x
PROVIDER: scopus
PUBMED: 20707797
DOI/URL:
Notes: --- - "Cited By (since 1996): 1" - "Export Date: 23 June 2011" - "CODEN: BJINF" - "Source: Scopus"
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MSK Authors
  1. Dean Bajorin
    658 Bajorin
  2. Satish K Tickoo
    485 Tickoo
  3. Anuradha Gopalan
    417 Gopalan
  4. Samson W Fine
    462 Fine
  5. Victor Reuter
    1228 Reuter
  6. Nicole Marie Leoce
    86 Leoce
  7. Maria E Dudas
    53 Dudas