[Inhibitory effect of recombinant transforming growth factor alpha-pseudomonas exotoxin 40 on human bladder cancer cell proliferation].

Abstract

OBJECTIVE:

To study inhibitory effect of recombinant transforming growth factor alpha-Pseudomonas exotoxin fusion protein (TP40) on proliferation of the human bladder cancer T24 cells.

METHODS:

Expression of epidermal growth factor receptor (EGFR) in cultured T24 cells was analyzed with Western blot assay. Human bladder cancer T24 cells were exposed to TP40 at 5 - 1 000 microg/L. Methyl thiazolyl tetrazolium assay was applied to evaluate the cell proliferation by measuring the absorbance (A) at 570 nm with a microplate reader. Tritium labeled thymine deoxyriboside ([(3)H]-TdR) uptake was measured to observe DNA synthesis. Competition assays were performed by the EGF at 1 - 7 500 microg/L.

RESULTS:

Expression of EGFR was high in human bladder cancer T24 cells. Cell growth was suppressed by 10%, 19%, 27%, 41%, 47%, 53% and 61% after 96 h treatment with TP40 at 5, 50, 100, 250, 500, 750 and 1 000 microg/L, respectively. [(3)H]-TdR incorporation was 80%, 69%, 48% and 51% after 24 h, 48 h, 72 h, 96 h treatment with TP40 at 750 microg/L, respectively. When the concentration was 1 - 7 500 microg/L, EGF could block the inhibitory effect of TP40 to some extent.

CONCLUSIONS:

Human bladder cancer T24 cells express EGFR at a high level. TP40 could inhibit the growth of T24 cells effectively in a dose- and time-dependent manner. The cytotoxic effects of TP40 were specifically mediated by EGFR.

• Authors: Xiang Yan, Qiang Ding, Yuan-fang Zhang, Yong-hua Xu
• Journal: Zhonghua wai ke za zhi [Chinese journal of surgery] (Zhonghua Wai Ke Za Zhi) Vol. 42 Issue 23 Pg. 1457-9 (Dec 07 2004) ISSN: 0529-5815 [Print] China
• PMID: 15733465 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Exotoxins
• Recombinant Fusion Proteins
• Transforming Growth Factor alpha
• transforming growth factor alpha-Pseudomonas exotoxin A (40)
• ErbB Receptors

Topics

• Cell Proliferation (drug effects)
• ErbB Receptors (metabolism)
• Exotoxins (pharmacology)
• Humans
• Recombinant Fusion Proteins (pharmacology)
• Transforming Growth Factor alpha (pharmacology)
• Tumor Cells, Cultured
• Urinary Bladder Neoplasms (metabolism, pathology)