Four-hourly scheduling of temozolomide improves tumour growth delay but not therapeutic index in A375M melanoma xenografts

2000 ◽  
Vol 45 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Mark R. Middleton ◽  
Jane Kelly ◽  
Sarah Goodger ◽  
Nicholas Thatcher ◽  
Geoffrey P. Margison
2020 ◽  
Vol 123 (7) ◽  
pp. 1089-1100 ◽  
Author(s):  
Yiannis Philippou ◽  
Hanna T. Sjoberg ◽  
Emma Murphy ◽  
Said Alyacoubi ◽  
Keaton I. Jones ◽  
...  

Abstract Background Radiotherapy enhances innate and adaptive anti-tumour immunity. It is unclear whether this effect may be harnessed by combining immunotherapy with radiotherapy fractions used to treat prostate cancer. We investigated tumour immune microenvironment responses of pre-clinical prostate cancer models to radiotherapy. Having defined this landscape, we tested whether radiotherapy-induced tumour growth delay could be enhanced with anti-PD-L1. Methods Hypofractionated radiotherapy was delivered to TRAMP-C1 and MyC-CaP flank allografts. Tumour growth delay, tumour immune microenvironment flow-cytometry, and immune gene expression were analysed. TRAMP-C1 allografts were then treated with 3 × 5 Gy ± anti-PD-L1. Results 3 × 5 Gy caused tumour growth delay in TRAMP-C1 and MyC-CaP. Tumour immune microenvironment changes in TRAMP-C1 at 7 days post-radiotherapy included increased tumour-associated macrophages and dendritic cells and upregulation of PD-1/PD-L1, CD8+ T-cell, dendritic cell, and regulatory T-cell genes. At tumour regrowth post-3 × 5 Gy the tumour immune microenvironment flow-cytometry was similar to control tumours, however CD8+, natural killer and dendritic cell gene transcripts were reduced. PD-L1 inhibition plus 3 × 5 Gy in TRAMP-C1 did not enhance tumour growth delay versus monotherapy. Conclusion 3 × 5 Gy hypofractionated radiotherapy can result in tumour growth delay and immune cell changes in allograft prostate cancer models. Adjuncts beyond immunomodulation may be necessary to improve the radiotherapy-induced anti-tumour response.


1974 ◽  
Vol 47 (560) ◽  
pp. 509-510 ◽  
Author(s):  
J. M. Brown ◽  
A. E. Howes

2000 ◽  
Author(s):  
K A Hartmann ◽  
U M Carl ◽  
P Sminia ◽  
G Lammering ◽  
K A Becker ◽  
...  

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