Journal
PLOS ONE
Volume 7, Issue 9, Pages -Publisher
PUBLIC LIBRARY SCIENCE
DOI: 10.1371/journal.pone.0045492
Keywords
-
Categories
Funding
- Oslo University Hospital
- Norwegian Ministry of Health
Ask authors/readers for more resources
Mapatumumab and lexatumumab (targeting death receptor 4 (DR4) and 5 (DR5), respectively) are agonistic TRAIL receptor antibodies that induce apoptosis in a wide range of cancer cells. The potency of mapatumumab and lexatumumab was assessed in mono therapy protocols, and the ability to sensitize for dacarbazine (DTIC) treatment was explored in ten different melanoma cell lines. Our data indicated that melanoma cell lines tend to be resistant to mapatumumab, most likely due to low expression of DR4, while a dose dependent response to lexatumumab was observed. Combining DTIC and lexatumumab induced an additive or synergistic effect on cell death in the various melanoma cell lines. The synergistic effect observed in the FEMX-1 cell line was related to enhanced cleavage of Bid in parallel with elevated expression of the pro-apoptotic proteins Bim, Bax and Bak. Furthermore, the anti-apoptotic proteins Bcl-XL, cIAP-1, XIAP and livin were down regulated. Cleavage of Bid and down regulation of cIAP-2 and livin were observed in vivo. Altogether, these data suggest a change in the balance between pro-and anti-apoptotic proteins favoring induction of apoptosis. In the more therapy resistant cell line, HHMS, no changes in the pro-and anti-apoptotic proteins were observed. FEMX-1 xenografts treated with DTIC and lexatumumab showed reduced growth and increased level of apoptosis compared to the control groups, providing arguments for further evaluation of this combination in melanoma patients.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available