In:
Cancer Research, American Association for Cancer Research (AACR), Vol. 75, No. 24 ( 2015-12-15), p. 5329-5340
Abstract:
Antibody–drug conjugates (ADC) target cytotoxic drugs to antigen-positive cells for treating cancer. After internalization, ADCs with noncleavable linkers are catabolized to amino acid-linker-warheads within the lysosome, which then enter the cytoplasm by an unknown mechanism. We hypothesized that a lysosomal transporter was responsible for delivering noncleavable ADC catabolites into the cytoplasm. To identify candidate transporters, we performed a phenotypic shRNA screen with an anti-CD70 maytansine-based ADC. This screen revealed the lysosomal membrane protein SLC46A3, the genetic attenuation of which inhibited the potency of multiple noncleavable antibody–maytansine ADCs, including ado-trastuzumab emtansine. In contrast, the potencies of noncleavable ADCs carrying the structurally distinct monomethyl auristatin F were unaffected by SLC46A3 attenuation. Structure–activity experiments suggested that maytansine is a substrate for SLC46A3. Notably, SLC46A3 silencing led to relative increases in catabolite concentrations in the lysosome. Taken together, our results establish SLC46A3 as a direct transporter of maytansine-based catabolites from the lysosome to the cytoplasm, prompting further investigation of SLC46A3 as a predictive response marker in breast cancer specimens. Cancer Res; 75(24); 5329–40. ©2015 AACR.
Type of Medium:
Online Resource
ISSN:
0008-5472
,
1538-7445
DOI:
10.1158/0008-5472.CAN-15-1610
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2015
detail.hit.zdb_id:
2036785-5
detail.hit.zdb_id:
1432-1
detail.hit.zdb_id:
410466-3
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