Abstract 3198: Therapeutic potential of MET inhibitor combined with immune checkpoint blockade in pancreatic cancer

Author(s):  
Mei Gao ◽  
Miranda Lin ◽  
Yachao Yang ◽  
Joseph Kim
Author(s):  
Daoxiang Zhang ◽  
Vikas Somani ◽  
Paarth B. Dodhiawala ◽  
Patrick M. Grierson ◽  
Lin Li ◽  
...  

2020 ◽  
Vol 21 (21) ◽  
pp. 8035
Author(s):  
Yang Yang ◽  
Nhi Huynh ◽  
Chelsea Dumesny ◽  
Kai Wang ◽  
Hong He ◽  
...  

The anti-cancer effects of cannabinoids including CBD (Cannabidiol) and THC ((−)-trans-∆9-tetrahydrocannabinol) have been reported in the case of pancreatic cancer (PC). The connection of these cannabinoids to KRas oncogenes that mutate in more than 90% of PC, and their effects on PD-L1, a key target of immune checkpoint blockade, have not been thoroughly investigated. Using cell lines and mouse models of PC, the effects of CBD and THC on cancer growth, the interaction between PC cells and a stromal cell, namely pancreatic stellate cells (PSCs), and the mechanism(s) involved were determined by cell-based assays and mouse study in vivo. CBD and THC inhibited the proliferation of PC, PSC, and PSC-stimulated PC cells. They also suppressed pancreatic tumour growth in mice. Furthermore, CBD and/or THC reduced the expression of PD-L1 by either PC or PSC cells. Knockout of p-21 activated kinase 1 (PAK1, activated by KRas) in PC and PSC cells and, in mice, dramatically decreased or blocked these inhibitory effects of CBD and/or THC. These results indicated that CBD and THC exerted their inhibitions on PC and PSC via a p-21 activated kinase 1 (PAK1)-dependent pathway, suggesting that CBD and THC suppress Kras activated pathway by targeting PAK1. The inhibition by CBD and THC of PD-L1 expression will enhance the immune checkpoint blockade of PC.


Author(s):  
Nancy Danielle Ebelt ◽  
Vic Zamloot ◽  
Edith Zuniga ◽  
Kevin B Passi ◽  
Lukas J. Sobocinski ◽  
...  

Therapeutic resistance in pancreatic ductal adenocarcinoma (PDAC) can be attributed, in part, to a dense extracellular matrix containing excessive collagen deposition. Here, we describe a novel Salmonella typhimurium (ST) vector expressing the bacterial collagenase Streptomyces omiyaensis trypsin (SOT), a serine protease known to hydrolyze collagens I and IV, which are predominantly found in PDAC. Utilizing aggressive models of PDAC, we show that ST-SOT selectively degrades intratumoral collagen leading to enhancement of immune checkpoint blockade (ICB) therapy in tumor-bearing mice. Ultimately, we found that ST-SOT treatment significantly modifies the intratumoral immune landscape to generate a microenvironment more conducive to ICB.


2021 ◽  
Vol 233 (5) ◽  
pp. S252-S253
Author(s):  
Luis I. Ruffolo ◽  
Nicholas A. Ullman ◽  
Katherine M. Jackson ◽  
Paul R. Burchard ◽  
Ryan C. Fields ◽  
...  

Open Biology ◽  
2021 ◽  
Vol 11 (11) ◽  
Author(s):  
Courtney T. Stump ◽  
Kevin Roehle ◽  
Nataly Manjarrez Orduno ◽  
Stephanie K. Dougan

Radiation has been a pillar of cancer therapy for decades. The effects of radiation on the anti-tumour immune response are variable across studies and have not been explicitly defined in poorly immunogenic tumour types. Here, we employed combination checkpoint blockade immunotherapy with stereotactic body radiation therapy and examined the effect on tumour growth and immune infiltrates in subcutaneous and orthotopic mouse models of pancreatic cancer. Although immune checkpoint blockade and radiation were ineffective alone, their combination produced a modest growth delay in both irradiated and non-irradiated tumours that corresponded with significant increases in CD8+ T cells, CD4+ T cells and tumour-specific T cells as identified by IFNγ ELISpot. We conclude that radiation enhances priming of tumour-specific T cells in poorly immunogenic tumours and that the frequency of these T cells can be further increased by combination with immune checkpoint blockade.


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