Activation of the mTORC2/Akt axis plays a crucial role in celastrol-induced paraptosis of breast cancer cells : 없음
Celastrol에 의한 항암 효과에 있어 mTORC2/Akt axis의 역할과 기전 연구
- 주제(키워드) paraptosis , celastrol , mTORC2 , Akt , ER stress , mitochondrial Ca2+
- 주제(DDC) 570
- 발행기관 아주대학교 일반대학원
- 지도교수 Kyeong Sook Choi
- 발행년도 2024
- 학위수여년월 2024. 8
- 학위명 석사
- 학과 및 전공 일반대학원 의생명과학과
- 실제URI http://www.dcollection.net/handler/ajou/000000034094
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Activation of the mTORC2/Akt axis plays a crucial role in celastrol- induced paraptosis of breast cancer cells Celastrol, a quinone methide triterpene derived from the Chinese medicinal plant Tripterygium wilfordii, has been shown in our previous study to induce paraptosis in breast cancer cells by perturbing Ca2+ homeostasis. In this study, we investigate the molecular mechanisms underlying celastrol-induced paraptosis, with a focus on the mTORC2/Akt signaling axis. My investigation revealed the transient activation of mTORC2/Akt is crucial for celastrol-induced paraptosis, as pharmacological inhibition of mTOR with PP242 and PI3K/Akt with LY294002, as well as genetic knockdown of mTOR and Akt, significantly reduced celastrol-induced cytotoxicity by delaying mitochondrial Ca2+ overload and alleviating proteotoxic stress. Notably, mTORC2, rather than mTORC1, plays a central role in this process. Akt inhibition, compared to mTOR inhibition, less effectively blocks celastrol-induced paraptosis, possibly due to the mitigation of the toxic effect by JNK activation, which is known to be a critical signal for paraptosis. Furthermore, the study shows that mTORC2- mediated mitochondrial Ca2+ overload and subsequent proteotoxic stress are pivotal in celastrol-induced paraptosis. This study also shows that celastrol selectively induces death in cancer cells while sparing non- transformed cells, highlighting its potential as a targeted anticancer agent. These insights emphasize the importance of targeting the mTORC2/Akt in cancer therapy, exploiting the vulnerabilities in cancer cells while minimizing harm to normal cells. This research opens new avenues for developing therapeutic strategies that enhance the efficacy of paraptosis inducers like celastrol by specifically targeting mTORC2/Akt-associated mechanisms. Further mechanistic studies are warranted to fully understand these processes and optimize celastrol’s therapeutic potential in cancer treatment. ____________________________________________________________ Keywords: paraptosis, celastrol, mTORC2, Akt, ER stress, mitochondrial Ca2+
more목차
I. INTRODUCTION 1
II. MATERIALS AND METHODS 9
A. Chemicals and antibodies 9
B. Cell culture 9
C. Cell viability assay 10
D. Live-cell imaging 10
E. Morphological examination of the ER and mitochondria 11
F. Measurement of mitochondrial Ca2+ levels 11
G. Measurement of acidic lysosome levels 11
H. Small interfering RNA-mediated knockdown 12
I. Immunoblot analysis 12
J. Statistical analysis 13
III. RESULTS 14
1. A transient activation of mTOR and Akt may be critical for celastrol-induced cell death 14
2. mTORC2, but not mTORC1, is critical for celastrol-induced paraptosis 29
3. Inhibition of mTOR or Akt delays mitochondrial calcium overload 33
4. Activation of mTOR/Akt axis contributes to celastrol-induced proteotoxic stress and paraptosis 38
5. Inhibition of mTOR, but not Akt inhibited JNK 42
6. Celastrol is not cytotoxic to MCF10A cells 47
7. mTOR-mediated autophagy is not critically involved in celastrol-induced cell death 50
IV. DISCUSSION 59
V. REFERENCES 71
VI. 국문요약 80
