Abstract
Purpose of Review
Epithelial cells line tissues and serve an important functional role in maintaining a barrier between tissue compartments and protection from the external environment. Tight Junctions and apical–basal polarity function to establish and maintain epithelial structures to prevent leakage between cells and define distinct subcellular domains to localize signaling pathways within cells that control growth, survival, and migration. Disruption of tight junctions and cell polarity is frequently observed in cancer.
Recent Findings
In this review, we discuss a role for Tight Junctions and the Par polarity complex as a sensor of epithelial integrity that contributes to maintaining epithelial homeostasis through apoptosis, proliferation, and stem cell renewal, and that disruption of these processes contributes to cancer progression.
Summary
Epithelial homeostasis is maintained by the spatial organization of signaling pathways within cells. Damaged cells are eliminated from the tissue by extrusion and apoptosis, and are balanced by proliferation and differentiation. Understanding the control of these processes during normal tissue development and homeostasis will lead to a more complete view of the etiology of cancer.
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Acknowledgments
We apologize to colleagues whose original work was not cited because of scope and space limitations. SJC is supported by a McGill Integrated Cancer Research Training Program (MICRTP) graduate studentship. RH is supported by a graduate studentship from FRQS and LM is a FRQS Scholar (Junior I). LM is funded by grants from the Cancer Research Society, Quebec Breast Cancer Foundation, and Canadian Institutes of Health Research. We also thank members of the McCaffrey Laboratory for helpful discussions.
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Sudipa June Chatterjee, Ruba Halaoui, and Luke McCaffrey declare that they have no conflict of interest.
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For articles cited in references for which one of the authors was also an author, we confirm that studies were performed in accordance with protocols that were approved by Institutional Animal Review Committees.
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Sudipa June Chatterjee and Ruba Halaoui have equally contributed to this work.
This article is part of the Topical collection on Leaky Junctions in Cancer.
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Chatterjee, S.J., Halaoui, R. & McCaffrey, L. Apical–Basal Polarity as a Sensor for Epithelial Homeostasis: A Matter of Life and Death. Curr Pathobiol Rep 4, 99–106 (2016). https://doi.org/10.1007/s40139-016-0107-5
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DOI: https://doi.org/10.1007/s40139-016-0107-5