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MA04 - HER2, P53, KRAS and Other Targets in Advanced NSCLC (ID 380)
- Event: WCLC 2016
- Type: Mini Oral Session
- Track: Advanced NSCLC
- Presentations: 1
MA04.10 - Lung Cancer Growth is Suppressed by CD26/DPP4-Inhibition via Enhanced NK Cell and Macrophage Recruitment (ID 6143)
16:00 - 17:30 | Author(s): S. Arni
Lung cancer is the leading cause of death among cancers. There is broad evidence that immune cells are involved in the growth and development of these malignancies. CD26/DPP4 (dipeptidyl peptidase 4) is a transmembrane glycoprotein, that is constitutively expressed on hematopoetic cells, but also found on lung epithelial and endothelial cells. We found previously that the activity of CD26/DPP4 of lung cancer patients at early stages is four times higher than in normal tissue. Here, we tested if CD26/DPP4-inhibition is able to modulate lung cancer growth in mice.
An orthotopic lung tumor model was employed by sc. injections of the mouse lung cancer (Lewis Lung Carcinoma (LLC)) and a human lung adenocarcinoma cell line (H460). These were developed in mice C57BL6 (n=18) and CD1-nude mice (n=20) respectively. The CD26/DPP4-inhibitor Vildagliptin was given in drinking water of 50mg/kg daily dose. Tumor growth was evaluated by wet weight of tumor mass at 2 weeks. Histological assessments included TUNEL, immunohistochemistry (IHC) of CD3, B220, F4/80 and NKp46. IL-10, Arginase, IL-12, NKp46, NK1.1, IFN-g, Granzyme, and Perforin 1 were analyzed by RT-PCR. In vitro analysis of surfactant protein (SP) expression in LLC and H460 were performed by western blotting. For a proof of concept, macrophage ablation was performed by clodronate-liposome during Vildagliptin treatment.
Vildagliptin treatment significantly reduced the tumor growth of both, LLC and H460 in mice. IHC showed macrophages (F4/80+) and NK cells (NKp46+) to be significantly increased by Vildagliptin within tumors, while TUNEL stain and IHC of T- and B cell infiltration did not show any difference. Gene expression levels of anti-inflammatory markers (IL-10, and Arginase) were unchanged, while the pro-inflammatory cytokine IL-12 was significantly elevated. The NK cell markers NKp46, NK1.1, IFN-g, Granzyme and Perforin 1 were significantly upregulated within the tumor by Vildagliptin, indicating that inhibition of CD26/DPP4 recruits NK cells into the tumor. Furthermore, we found enhanced SP expressions in lung cancer cell lines by Vildagliptin treatment in vitro. Macrophage ablation with clodronate-liposome in Vildagliptin treated mice reversed the tumor size significantly.
The Inhibition of CD26/DPP4 decreased lung cancer growth in primary models of mouse and human lung cancer and increased inflammatory macrophages and NK cell cytotoxicity within those tumors. Furthermore, an increased expression of SP by Vildagliptin treatment in lung cancer cell lines suggests that surfactant production in lung cancer activates macrophages to fight against lung cancer via the recruitment of macrophages and NK cells.
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