Tumorigenic conversion of primary human esophageal epithelial cells using oncogene combinations in the absence of exogenous ras

• Published in: Cancer research (Chicago, Ill.) Vol. 66; no. 21; pp. 10415 - 10424
• Main Authors: KIM, Seok-Hyun, NAKAGAWA, Hiroshi, NAVARAJ, Arunasalam, NAOMOTO, Yoshio, KLEIN-SZANTO, Andres J. P, RUSTGI, Anil K, EL-DEIRY, Wafik S
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01-11-2006
• Subjects: Aneuploidy; Animals; Antineoplastic agents; bcl-X Protein - analysis; Biological and medical sciences; Cell Line, Transformed; Cell Transformation, Neoplastic; Epithelial Cells - pathology; Esophageal Neoplasms - etiology; Gene Expression Profiling; Genes, myc; Genes, ras; Humans; Medical sciences; Mice; Mice, Inbred BALB C; Neoplasm Transplantation; Oncogenes; Pharmacology. Drug treatments; Proto-Oncogene Proteins c-akt - genetics; Receptor, Epidermal Growth Factor - genetics; Transplantation, Heterologous; Tumors; Human; Exogenous; Digestive system; C-Onc gene; Primary; Epithelial cell; Tumorigenicity; Onc gene; Conversion; Protooncogene; Esophagus
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/0008-5472.CAN-06-2104

To investigate pathways of human esophageal squamous cell transformation, we generated esophageal tumor cells using human telomerase- and SV40-immortalized primary esophageal epithelial cells (EPC2) by overexpression of selected combinations of oncogenes. H-Ras, c-Myc, or Akt, but not epidermal growth factor receptor (EGFR), induced transformed colonies in soft agar. By contrast, bioluminescence imaging of genetically altered immortalized esophageal cells revealed that Akt, EGFR, or H-Ras, but not c-Myc, resulted in tumor formation in immunodeficient mice. H-Ras-driven tumors showed highly tumorigenic phenotypes with 2.6 +/- 0.6 days for doubling, whereas Akt and EGFR tumors doubled every 9.5 +/- 1.6 and 6.1 +/- 1.2 days, respectively. H-Ras-driven tumors expressed the hypoxia-inducible factor target Glut1, whereas Akt- or EGFR-driven tumors had evidence of angiogenesis and no detectable Glut1 expression. Proliferation rates among these tumors were similar, but there was reduced apoptosis in the more aggressive H-Ras-driven tumors that also developed aneuploidy and multiple centrosomes. c-Myc overexpression did not result in tumorigenic conversion but introduction of Bcl-XL into c-Myc-expressing cells generated tumors. Although cytokeratin expression was typical of squamous carcinoma, gene expression profiling was done to compare the four different types of engineered tumors with human esophageal squamous cell carcinomas and adenocarcinomas. Interestingly, c-Myc plus Bcl-XL transformants mimicked squamous carcinomas, whereas H-Ras-, EGFR-, and Akt-driven tumors were similar to adenocarcinomas in their molecular profiles. These genetically engineered models may provide new platforms for understanding human esophagus cancer and may assist in the evaluation of new therapies.