MIM, a potential metastasis suppressor gene in bladder cancer

Abstract

Using a modified version of the mRNA differential display technique, five human bladder cancer cell lines from low grade to metastatic were analyzed to identify differences in gene expression. A 316-bp cDNA (C11-300) was isolated that was not expressed in the metastatic cell line TccSuP. Sequence analysis revealed that this gene was identical to KIAA 0429, has a 5.3-kb transcript that mapped to 8q24.1. The protein is predicted to be 356 amino acids in size and has an actin-binding WH2 domain. Northern blot revealed expression in multiple normal tissues, but none in a metastatic breast cancer cell line (SKBR3) or in metastatic prostatic cancer cell lines (LNCaP, PC3). We have named this gene Missing in Metastasis (MIM) and our data suggest that it may be involved in cytoskeletal organization.

Figure 1

The 316-bp cDNA is not expressed in TccSup (Lane 6) by PCR. Lane 1: 100-bp DNA marker. Lane 2: RT4 (bladder papilloma cell line). Lane 3: 5637 (bladder superficial transitional cell line). Lane 4: HT 1376 (bladder invasive TCC cell line). Lane 5: T24 (bladder invasive TCC cell line). Lane 6: TccSup (metastatic bladder TCC cell line).

Figure 2

Northern blot analysis of cell lines and tissues utilizing the C11 300 cDNA as a probe. A. Bladder cancer cell lines. B. Normal tissues. C. Breast cancer cell lines. D. Prostate cancer cell lines.

Figure 3

The protein sequence for MIM. The predicted protein sequence is 356 bp. The proline-rich region stretches from bp 209 to 284 (bold italicized). The WH2 domain encompasses the bp region 328 to 345 (bold underlined).