Interstitial deletion of 11q13 sequences in HeLa cells

Previous cytogenetic and molecular genetic studies have shown that the HeLa (cervical carcinoma) cell line D98/AH-2 contains two apparently normal cop ies of chromosome II and additional 11q13-25 material translocated onto a c hromosome 3 marker. To determine the 11q13 breakpoint, we performed fluores cence in situ hybridization (FISH) using 18 different 11q13 specific BAC (b acterial artificial chromosome) and cosmid probes spanning a 5.6 Mb interva l. Markers localized to the multiple endocrine neoplasia type I (MEN1) gene (menin) were also included in the analysis. The FISH study identified an i nterstitial deletion between markers DIIS449 and GSTPI, an interval of 2.3 Mb, in the marker chromosome. This deletion did not include the MEN1 gene. Because point mutations and methylations can inactivate the MEN1 gene, sing le stranded conformational polymorphism (SSCP) and Northern and Western blo t analyses were performed with MEN1 specific probes and antibody. SSCP did not reveal mutations of the MEN1 gene in HeLa or in seven other cervical ca ncer cell lines. Northern and Western blot studies revealed normal levels o f expression of this gene in the cervical cancer cell lines as well as in H ela cell derived tumorigenic hybrids. Because deletions of tumor suppressor genes often occur in cancer progression, we hypothesize that the inactivat ion of a tumor suppressor gene other than MEN1, localized to the 2.3 Mb int erval on 11q13, might play a role in the abnormal growth behavior of HeLa c ells in vitro or in vivo. (C) 2000 Wiley-Liss, Inc.