In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 31, No. 6_suppl ( 2013-02-20), p. 294-294
Abstract:
294 Background: Lenalidomide (Len) is an immunomodulatory drug (IMiD) approved for hematologic conditions and demonstrates immune modulation, anti-angiogenic activity and direct anti-tumor cytotoxicity. A rationale can be made to evaluate the preclinical activity of Len in UC. Methods: The in vitro anti-tumor activity of Len was evaluated in 4 human (5637, TCC-SUP, RT4, RT112) and 1 murine (MB49) cell line. Anti-proliferative activity activity (MTT assay), apoptosis (Annexin-FITC immunohistochemistry [IHC], flow cytometry) and cell viability by colony forming assay were measured. In vivo activity of daily oral Len 10 mg/kg or placebo orally for 5 days a week for up to 4 weeks was examined in syngeneic immunocompetent C57BL/6 mice bearing subcutaneous (SC) MB49-Luc25 tumors and RT4 subcutaneous xenografts. Tumors underwent immunohistochemistry (IHC) for microvessel density (CD31), apoptosis (cleaved caspase [cc] -3) and CD3+/CD20+ lymphocyte infiltration. Cereblon, a molecular target of Len was analyzed by IHC. Results: In vitro cultures for 3 days with daily repletion of Len showed significant pro-apoptotic activity (flow cytometry) at low micromolar concentrations attainable in human subjects (2.2 µM) against RT4 cells, a superficially invasive human UC cell line. Long-term cultures of RT4 cells for 2 weeks with daily repletion of Len significantly reduced cell viability and colony forming ability. Cereblon expression was numerically lower in sensitive RT4 cells compared to resistant 5637 cells (p=NS). In the immunocompetent model in vivo, Len did not decrease tumor size, or increase cc-3 and CD3+/CD20+ lymphocytes, but post-Len tumors exhibited decreased CD31 (p 〈 0.05). In RT4 xenografts, Len significantly decreased the size of tumors and CD31, and increased cc-3 (all p 〈 0.05). Cereblon expression increased in Len treated RT4 xenografts (p=0.024). Conclusions: Lenalidomide demonstrated selective preclinical activity against superficially invasive low grade human UC cells attributable to direct tumor cell apoptosis and anti-angiogenic activity. Clinical evaluation in patients with low grade or non-invasive UC and further study of cereblon as a predictive biomarker may be warranted.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2013.31.6_suppl.294
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2013
detail.hit.zdb_id:
2005181-5
detail.hit.zdb_id:
604914-X
