Abstract 411: Chromatin regulatory nuclear proteins and nuclear architecture in cell lines derived from curable and incurable metastatic human cancers.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Introduction and Objective: Historically an impressive response to chemotherapy for metastatic testicular cancer is in stark contrast to the dismal results with metastatic pancreatic cancers. Based on our hypothesis that nuclear chromatin structure plays a key role in determining the aggressiveness and the curability of cancer, and the chromatin regulatory proteins alter nuclear structure and hence may be differentially expressed between curable and incurable cancers, we have studied several of these proteins in Tera-1 & Tera-2 (from metastatic testicular carcinoma) and in PANC-1 & CAPAN-1 (from metastatic pancreatic cancer) cell lines.- The nuclear protein targets are SATB1 (special AT-rich sequence-binding protein-1), HP1 (Heterochromatin Protein 1), NUMA (nuclear mitotic apparatus protein), Transcriptional repressor CTCF (11-zinc finger protein), Lamin A/C, Lamin B, and High-mobility group AT-hook 1 (HMGA1). Methods: The cell lines were grown in 4-well chamber slides coated with poly- L-lysine (BD, USA) using specific media. After fixing the cells with acetone: methanol (1:1), immunocytochemistry was done using specific commercial antibodies, biotinylated secondary antibody, Avidin/Biotinylated Complex system and Vector red dye. Some proteins were not done in Tera-1 cell lines since we had some problems in culturing them. Nuclear morphometry was quantified using Feulgen stained nuclei captured by the AutoCyte Pathology Workstation which calculated - features of shape, size, DNA content and texture. Results: The nuclear chromatin protein expressions of CTCF, HP1, HMGA1 and NuMA were determined as moderate (2+) to strong (3-4+) in pancreatic cell lines, but were weak (≤1+) to no expression in testicular cancer cell lines. For Lamin A/C, though no significant difference between the cell lines occurred, in the testicular cells the expression was confined to nucleus whereas in pancreatic cells staining was both nuclear and cytoplasmic. The expression of Lamin B did not differ between cell lines and no expression of SAT B1 was found in the cell lines. The nuclear morphometry features showed significant difference in DNA content and size & shape factors between pancreatic and testicular cell lines. Conclusions: Our preliminary results indicate that the differential expression of nuclear chromatin regulatory proteins may play an important role in responsiveness to treatment and might offer new targets for study. Further, measurement of nuclear structure support alterations in nuclear shape and DNA content commensurate with these nuclear protein studies. Funding: National Cancer Institute of the National Institutes of Health through awards funded under Grant number 1U54CA143803-03. Citation Format: Robert W. Veltri, Christhunesa S. Christudass, Sneha Vivekanandhan, David Yeater, Donald S. Coffey. Chromatin regulatory nuclear proteins and nuclear architecture in cell lines derived from curable and incurable metastatic human cancers. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 411. doi:10.1158/1538-7445.AM2013-411