Tumor dormancy and cancer stem cells: two sides of the same coin?

Adv Exp Med Biol. 2013:734:145-79. doi: 10.1007/978-1-4614-1445-2_8.

Abstract

Increasing evidence suggests that tumor dormancy represents an important mechanism underlying the observed failure of existing therapeutic modalities to fully eradicate cancers. In addition to its more established role in maintaining minimal residual disease after treatment, dormancy might also critically contribute to early stages of tumor development and the formation of clinically undetectable micrometastatic foci. There are striking parallels between the concept of tumor dormancy and the cancer stem cell (CSC) theory of tumor propagation. For instance, the CSC hypothesis similarly predicts that a subset of self-renewing cancer cells-that is CSCs-is responsible for tumor initiation, bears the preferential ability to survive tumor therapy, and persists long term to ultimately cause delayed cancer recurrence and metastatic progression. Additionally, many of the biological mechanisms involved in controlling the dormant state of a tumor can also govern CSC behavior, including cell cycle modifications, alteration of angiogenic processes, and modulation of antitumor immune responses. In fact, quiescence and immune escape are emerging hallmark features of at least some CSCs, indicating significant overlap between dormant cancer populations and CSCs. Herein, we crucially dissect whether CSCs occupy specific roles in orchestrating the switch between dormancy and exuberant tumor growth. We elucidate how recently uncovered CSC biological features could enable these cells to evade immunologic clearance and regulate cancer expansion, relapse, and progression. We propose that the study of CSC immunobiological pathways holds the promise to critically advance our understanding of the processes mediating tumor dormancy. Ultimately, such research endeavors could unravel novel therapeutic avenues that efficiently target both proliferating and dormant CSCs to minimize the risk of tumor recurrence in cancer patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Cell Communication
  • Cell Cycle Checkpoints
  • Cell Death
  • Cell Movement
  • Cell Proliferation
  • Cell Transformation, Neoplastic / immunology
  • Cell Transformation, Neoplastic / pathology
  • Combined Modality Therapy / methods
  • Disease Progression
  • Drug Resistance, Neoplasm
  • Humans
  • Neoplasm Metastasis / immunology
  • Neoplasm Metastasis / pathology
  • Neoplasm Metastasis / therapy
  • Neoplasm Recurrence, Local / blood supply
  • Neoplasm Recurrence, Local / immunology
  • Neoplasm Recurrence, Local / pathology*
  • Neoplasm Recurrence, Local / therapy
  • Neoplasm, Residual / immunology
  • Neoplasm, Residual / pathology
  • Neoplasm, Residual / therapy
  • Neoplastic Stem Cells / immunology
  • Neoplastic Stem Cells / pathology*
  • Neovascularization, Pathologic / immunology
  • Neovascularization, Pathologic / pathology
  • Neovascularization, Pathologic / therapy
  • Signal Transduction
  • Tumor Escape
  • Tumor Microenvironment

Substances

  • Antineoplastic Agents