EMT transcription factors snail and slug directly contribute to cisplatin resistance in ovarian cancer

웨스턴 월드의 여성에게 높은 치사율을 보이는 난소암. 캐나다에서는 71 명 중 1명이 발병된다고 하며, 증세가 말기에 발견되고 효과적인 스크린닝 기술이 없어 치사율이 높다고 한다. 또한 수술과 항암제를 사용하여 치료하지만 20% 환자에서 항암제 저항성을 보인다고 한다. 항암제인 cisplatin은 백금 혼합물로서 DNA에 결합하여 복제나 회복 기능을 막음으로 세포의 apoptosis를 유도한다.

 배발생 과정에 대한 연구로 많이 알려진 EMT가 암의 진행에도 관여한다는 연구들이 최근 많이 보고 되고 있다. EMT가 항암제 저항성 발달에 중요한 역할을 할 것이다는 증거들도 나오고 있다. EMT의 특징은 extracellular matrix components의 증가와 세포간 접착력 감소, migration/invasion 능력 증가 등을 들 수 있으며, SNAI1(snail), SNAI2(slug) 등의 특정 유전자들이 발현된다.

이 실험에서는 A2780이라는 ovarian adenocarcinoma cell line이 사용되었으며, 대조군으로 배지에 1uM cis를 처리한 A2780cis를 비교하여 표현형, 유전자, 단백질 등을 비교하였다.

 

- 이미 EMT 부분에서 많이 알려진 내용들을 가지고 실험한 것으로 EMT transcription factor 들이 방사선이나 항암제에 저항성에 영향을 미치며 knockdown 시켰을 경우 더 sensitive하게 해준다는 내용인데,

한가지 의문이 A2780 cis를 유지할 수 있는 부분이다. cisplatin-resistant cell을 만들기가 굉장히 어려운 것으로 알려져 있다. 실험 방법 내용에 시간이나 상태 등을 자세히 알 수 없어 조금 아쉽다.

 

 

BMC cancer (IF 3.1)

EMT transcription factors snail and slug directly contribute to cisplatin resistance in ovarian cancer

 

Alexandria M Haslehurst1, Madhuri Koti1, Moyez Dharsee4, Paulo Nuin1,4, Ken Evans1,4, Joseph Geraci4,
Timothy Childs1, Jian Chen4, Jieran Li4, Johanne Weberpals2, Scott Davey1, Jeremy Squire1,3, Paul C Park1 and
Harriet Feilotter1,4*

 

Abstract
Background: The epithelial to mesenchymal transition (EMT) is a molecular process through which an epithelial
cell undergoes transdifferentiation into a mesenchymal phenotype. The role of EMT in embryogenesis is wellcharacterized and increasing evidence suggests that elements of the transition may be important in other
processes, including metastasis and drug resistance in various different cancers.

Methods: Agilent 4 × 44 K whole human genome arrays and selected reaction monitoring mass spectrometry
were used to investigate mRNA and protein expression in A2780 cisplatin sensitive and resistant cell lines. Invasion
and migration were assessed using Boyden chamber assays. Gene knockdown of snail and slug was done using
targeted siRNA. Clinical relevance of the EMT pathway was assessed in a cohort of primary ovarian tumours using
data from Affymetrix GeneChip Human Genome U133 plus 2.0 arrays.

Results: Morphological and phenotypic hallmarks of EMT were identified in the chemoresistant cells. Subsequent
gene expression profiling revealed upregulation of EMT-related transcription factors including snail, slug, twist2 and
zeb2. Proteomic analysis demonstrated up regulation of Snail and Slug as well as the mesenchymal marker
Vimentin, and down regulation of E-cadherin, an epithelial marker. By reducing expression of snail and slug, the
mesenchymal phenotype was largely reversed and cells were resensitized to cisplatin. Finally, gene expression data
from primary tumours mirrored the finding that an EMT-like pathway is activated in resistant tumours relative to
sensitive tumours, suggesting that the involvement of this transition may not be limited to in vitro drug effects.
Conclusions: This work strongly suggests that genes associated with EMT may play a significant role in cisplatin
resistance in ovarian cancer, therefore potentially leading to the development of predictive biomarkers of drug
response or novel therapeutic strategies for overcoming drug resistance.