Related Experiment Video
Updated: May 20, 2026
07:20
Exploring the Regulation of Lipid Droplet Catabolism through Lipophagy
Published on: January 31, 2025
Tumor cells can evade dependence on autophagy through adaptation
Wen-Xing Ding1, Xi Chen, Xiao-Ming Yin
1Department of Pharmacology, Toxicology, and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA.
Biochemical and Biophysical Research Communications
|July 31, 2012
Summary
Long-term autophagy deficiency, either before or after cancer transformation, can make tumor cells independent of autophagy for survival. This long-term deficiency also means chemotherapy response is unaffected by manipulating autophagy status.
Area of Science:
- Cellular Biology
- Cancer Research
- Molecular Biology
Background:
- The proteasome and autophagy-lysosome pathways are key intracellular degradation systems.
- Cancer cells rely on autophagy for survival, making them vulnerable to autophagy inhibition.
Purpose of the Study:
- To investigate if long-term autophagy deficiency impacts cancer cell dependency on autophagy.
- To determine how chronic versus acute autophagy inhibition affects cancer cell sensitivity to proteasome inhibitors.
Main Methods:
- Transformed wild-type and autophagy-deficient (Atg5 knockout) cells with activated Ras.
- Acute and constitutive knockdown of Beclin 1 in a glioblastoma cell line using siRNA.
- Assessed sensitivity to proteasome inhibitors in various autophagy-deficient and intact cancer models.
Main Results:
- Autophagy-deficient tumor cells were not more susceptible to proteasome inhibitors than wild-type tumor cells post-transformation.
- Acute Beclin 1 knockdown increased glioblastoma cell sensitivity to proteasome inhibitors.
- Constitutive Beclin 1 knockdown did not alter glioblastoma cell sensitivity to proteasome inhibitors compared to wild-type cells.
Conclusions:
- Long-term autophagy deficiency, established before or after oncogenic transformation, can lead to autophagy-independent tumor cell survival.
- The therapeutic response to proteasome inhibitors is not influenced by long-term autophagy status manipulation in cancer cells.
Related Concept Videos
02:53Adaptive Mechanisms in Cancer Cells
Cancer cells accumulate genetic changes at an abnormally rapid rate due to the defects in the DNA repair mechanisms. From an evolutionary perspective, such genetic instability is advantageous for cancer development. Mutant cell lines accumulate a series of beneficial mutations that contribute to their progression into cancer.
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
02:53Adaptive Mechanisms in Cancer Cells
Cancer cells accumulate genetic changes at an abnormally rapid rate due to the defects in the DNA repair mechanisms. From an evolutionary perspective, such genetic instability is advantageous for cancer development. Mutant cell lines accumulate a series of beneficial mutations that contribute to their progression into cancer.
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
03:03mTOR Signaling and Cancer Progression
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
03:03mTOR Signaling and Cancer Progression
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
01:27Autophagy
Autophagy is a self-digesting process by which a cell protects itself from threats both within and outside the cell, ranging from abnormal proteins to invading bacteria. In this process, obsolete components of the cell and invading microbes are degraded by hydrolytic enzymes active in an acidic environment of the lysosomal lumen.
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
02:56Treatment Resistant Cancers
Cancer is the second leading cause of death in the United States. A cancer cell is genetically unstable and hence can mutate faster. They can also modify their microenvironment and escape immune surveillance. The difficulties in treating cancer are further compounded by the emergence of rapid resistance to anticancer drugs. The most common ways to attain resistance in cancer cells include alteration in drug transport and metabolism, modification of drug target, elevated DNA damage response, or...