Although Epithelial-Mesenchymal Transition (EMT) in cancers remains controversial, its relevance in tumor progression is a subject of investigation. The presence of cellular changes associated with EMT in bladder tumor progression have been well investigated, unlike other human carcinomas with very little data available to date. ZEB-1 which targets E-Cadherin repression is a transcriptional regulator that has been implicated in EMT, and its nuclear expression in tumor cells has been associated with aggressive malignancies in some types of cancer. Recently, it was also reported that ZEB-1 inhibits the expression of proapoptotic factor B-cell lymphoma (Bcl)-2 interacting mediator of cell death (BIM) by binding directly to the BIM promoter and repressing its transcription. We tested this hypothesis with a human cohort of 24 Cholangiocarcinoma (CC), 18 Hepatocellular (HCC) and 31 Renal Cell (RCC) human carcinomas. Formalin fixed paraffin embedded tissue sections containing benign and tumor lesions were immunostained using the Dako Autostainers Link 48 along with ZEB-1 monoclonal OT13G6 (ABCAM), Bcl-2 monoclonal 124 (Agilent, Dako), and E-Cadherin monoclonal NCH-38 (Agilent, Dako) antibodies. Nuclear, membraneous and/or cytoplasmic immunoreactivity was scored based on the intensity and percentage of positive cells in both the benign epithelium and adjacent tumor in each case. E-Cadherin was highly expressed in both the adjacent benign and malignant components with no significant variability in all three carcinomas, with ZEB-1 and Bcl-2 evaluated for the any positivity staining in both components for all cases. Results are detailed in the table below.All positive ZEB-1 cases in HCC were in high grade cases unlike the positive ZEB-1 in RCC which were in low grade cases. But more noticeably, 8/10 (80%) positive ZEB-1 were also positive for Bcl-2 in all three carcinoma types. Despite the small number of cases analyzed in this cohort a trend in the expression of ZEB-1 and its co-expression with BCL-2 may have some prognostic implications. We are currently extending this analysis to a larger number of CC, HCC, and RCC to closely examine the significance of ZEB-1, and Bcl-2 expression across differently graded lesions to further test our hypothesis.

Citation Format: Joeffrey J. Chahine, Kyungmin Ko, Bhaskar VS Kallakury, Pamela L. Tuma. Variable expression of ZEB-1, Bcl-2, and E-cadherin in human hepatocholangio and renal cell carcinomas [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6471.