1997 Fiscal Year Final Research Report Summary
Isolation and characterization of rat urinary bladder cancer cell lines with different invasive activities
| Project/Area Number |
08671819
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Urology
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| Research Institution | Kagawa Medical University |
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Principal Investigator |
NISHI Nozomu Kagawa Medical University, Dept.of Endocrinology, Research Associate, 医学部, 助手 (10145047)
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| Co-Investigator(Kenkyū-buntansha) |
TAKETA Shigeo Kagawa Medical University, Dept.of Urology, Assistant Professor, 医学部・附属病院, 講師 (10227027)
MATSUOKA Noriyoshi Kagawa Medical University, Dept.of Urology, Assistant Professor, 医学部・附属病院, 講師 (20165781)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Bladder cancer / Invasion / Metastasis / Cell adhesion / E-cadherin / Catenin / Epithelin / Growth factor |
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| Research Abstract |
We isolated, in vitro, spontaneous variants of the rat bladder tumor NBT-II cell line with a distinctive morphology. Of five sublines obtained, three (NBT-L1, L2a, and L2b) exhibited an elongated shape and moderate to high invasive activity in vitro. The other two sublines (NBT-T1 and T2) formed tight colonies and exhibited very low or negligible invasive activity. The contents of mRNAs coding for cell adhesion molecules (E-cadherin, a-catenin and b-catenin) were not correlated with the invasive activity of the cells. However, the expression level of the E-cadherin protein, but not those of catenins, was lower in invasive cells (NBT-L1, L2a and L2b) than in noninvasive cells (NBT-T1 and T2) . Analysis of mRNAs coding for several growth factors and their receptors showed that the transforming growth factor-alpha (TGF-alpha) mRNA content in invasive cells was higher than that in noninvasive cells, and that the content of epidermal growth factor receptor mRNA was low in NBT-T2. Although NBT-II is known to acquire a fibroblastic appearance and cell motility in response to several growth factors, the conditioned media of the invasive sublines hardly affected the morphology or motility of noninvasive cells. These results indicate that the decreased E-cadherin expression is a major cause of the transition from the noninvasive to the invasive phenotype of the bladder tumor cells, and that post-transcriptional process is important in the control of E-cadherin expression in the cells. These sublines may constitute useful models for studies on the malignant transformation of bladder tumors.
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