The Controversial Role of Autophagy in Tumor Development: A Systematic Review

ABSTRACT

Autophagy is a natural regulatory mechanism of the cell that eliminates unnecessary and dysfunctional cellular components to maintain homeostasis. Several authors have demonstrated that this mechanism can be induced by pathological conditions as cancer. However, their role in tumor development is still a controversial issue in cancer research. Here, we discussed the most relevant findings concerning autophagy in tumor development. In this critical review performed with studies published between 2002 and 2018, we found that the main pathway involved in the autophagy process is the PI3K/AKT/mTOR intracellular signaling pathway. Regarding their role in cancer development, breast cancer is the main study target, followed by lung, prostate and colon cancer. In these issues, 46% of the works consulted suggesting that autophagy inhibits tumor progression by favor a better antitumor response, 4% suggest that favors growth and tumor progression and, 50% of the authors failed to establish whether autophagy inhibits or favors tumor development. Herein, we concluded that depending on the study model, autophagy may favor or inhibits growth and cancer progression.

KEYWORDS:

• Autophagocytosis
• cancer
• cell death
• homeostasis
• ATG proteins
• PI3K/AKT/mTOR intracellular signaling pathway

Conflict of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the manuscript.

Supplementary Material

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Additional information

Funding

This work was supported by Banco Santander, grant for undergraduate student 2016/2107; Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP grant # 2017/04176-7.