Format

Send to

Choose Destination
Biochem Biophys Res Commun. 2016 Sep 30;478(4):1515-20. doi: 10.1016/j.bbrc.2016.08.126. Epub 2016 Aug 24.

mTOR inhibition sensitizes ONC201-induced anti-colorectal cancer cell activity.

Author information

1
Department of Colorectal Surgery, Hangzhou Red Cross Hospital, Hangzhou, China.
2
Department of Colorectal Surgery, Hangzhou Red Cross Hospital, Hangzhou, China. Electronic address: jin_yongjun82@126.com.

Abstract

We here tested the anti-colorectal cancer (CRC) activity by a first-in-class small molecule TRAIL inducer ONC201. The potential effect of mTOR on ONC201's actions was also examined. ONC201 induced moderate cytotoxicity against CRC cell lines (HT-29, HCT-116 and DLD-1) and primary human CRC cells. Significantly, AZD-8055, a mTOR kinase inhibitor, sensitized ONC201-induced cytotoxicity in CRC cells. Meanwhile, ONC201-induced TRAIL/death receptor-5 (DR-5) expression, caspase-8 activation and CRC cell apoptosis were also potentiated with AZD-8055 co-treatment. Reversely, TRAIL sequestering antibody RIK-2 or the caspase-8 specific inhibitor z-IETD-fmk attenuated AZD-8055 plus ONC201-induced CRC cell death. Further, mTOR kinase-dead mutation (Asp-2338-Ala) or shRNA knockdown significantly sensitized ONC201's activity in CRC cells, leading to profound cell death and apoptosis. On the other hand, expression of a constitutively-active S6K1 (T389E) attenuated ONC201-induced CRC cell apoptosis. For the mechanism study, we showed that ONC201 blocked Akt, but only slightly inhibited mTOR in CRC cells. Co-treatment with AZD-8055 also concurrently blocked mTOR activation. These results suggest that mTOR could be a primary resistance factor of ONC201 in CRC cells.

KEYWORDS:

AZD-8055; Colorectal cancer; ONC201; TRAIL; mTOR

PMID:
27565731
DOI:
10.1016/j.bbrc.2016.08.126
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center