Functions of autophagy in the tumor microenvironment and cancer metastasis

Abstract

Macro-autophagy is an ancient and highly conserved self-degradative process that plays a homeostatic role in normal cells by eliminating organelles, pathogens, and protein aggregates. Autophagy, as it is routinely referred to, also allows cells to maintain metabolic sufficiency and survive under conditions of nutrient stress by recycling the by-products of autophagic degradation, such as fatty acids, amino acids, and nucleotides. Tumor cells are more reliant than normal cells on autophagy for survival in part due to their rapid growth rate, altered metabolism, and nutrient-deprived growth environment. How this dependence of tumor cells on autophagy affects their progression to malignancy and metastatic disease is an area of increasing research focus. Here, we review recent work identifying critical functions for autophagy in tumor cell migration and invasion, tumor stem cell maintenance and therapy resistance, and cross-talk between tumor cells and their microenvironment.

11-Methoxytabersonine Induces Necroptosis with Autophagy through AMPK/mTOR and JNK Pathways in Human Lung Cancer Cells

“…For example, shikonin is the first natural compound reported to induce necroptosis in osteosarcoma, 28) glioma 29) and multiple myeloma cells 30) ; Curcumin induces extracellular signal-regulated kinase (ERK) or p38/JNK phosphorylation followed by production of abundant reactive oxygen species (ROS) that promote necroptosis in prostate cancer cells. 31) In this study, 11-MT induced necroptotic cell death in lung cancer cells. Such role of natural compounds in regulating necroptosis will hopefully provide prospective strategies to manipulate tumor cell death.…”

Fluid shear stress induces cell migration and invasion via activating autophagy in HepG2 cells

“…Inhibition of autophagy by 3-MA and lentivirusderived Atg5 shRNA ( Figure 5) suppressed the cell migration and invasion in presence of FSS ( Figure 6), suggesting FSS plays an important role in metastasis of cancer cells through autophagy pathway. Autophagy is important for maintaining cellular homeostasis by removing protein aggregates and destructing cellular organelles, as well as recycling the by-products of autophagic degradation [16]. Increasing evidences demonstrated that autophagy directly involved in tumor cell motility and invasion during metastasis, in part through turnover of components of the cell migration machinery such as focal adhesions [34].…”

“…During autophagy, a series of autophagic markers such as Beclin-1, Atg5, Atg7 and LC3B-II associated with the formation of autophagosome are largely activated [16]. LC3B-II is localized and aggregated in autophagosomes.…”

“…In recent, it was demonstrated that autophagy plays an important role in cancer metastasis [16]. FSS could induce autophagy in various cancer cells, such as cervical cancer cells and HCC cells [17,18].…”

Long non‑coding RNA DLX6‑AS1 silencing inhibits malignant phenotypes of gastric cancer cells

“…Tumor cell migration and invasion are essential for tumor metastasis (22). Wound healing and transwell assays were performed to assess the function of DLX6-AS1 in GC cell migration and invasion.…”