Trimodal cancer treatment: beneficial effects of combined antiangiogenesis, radiation, and chemotherapy.
It has been suggested that chemotherapy and radiotherapy could favorably be combined with antiangiogenesis in dual anticancer strategy combinations. Here we investigate the effects of a trimodal strategy consisting of all three therapy approaches administered concurrently. We found that in vitro and in vivo, the antiendothelial and antitumor effects of the triple therapy combination consisting of SU11657 (a multitargeted small molecule inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptor tyrosine kinases), Pemetrexed (a multitargeted folate antimetabolite), and ionizing radiation were superior to all single and dual combinations. The superior effects in human umbilical vein endothelial cells and tumor cells (A431) were evident in cell proliferation, migration, tube formation, clonogenic survival, and apoptosis assays (sub-G1 and caspase-3 assessment). Exploring potential effects on cell survival signaling, we found that radiation and chemotherapy induced endothelial cell Akt phosphorylation, but SU11657 could attenuate this process in vitro and in vivo in A431 human tumor xenografts growing s.c. on BALB/c nu/nu mice. Triple therapy further decreased tumor cell proliferation (Ki-67 index) and vessel count (CD31 staining), and induced greater tumor growth delay versus all other therapy regimens without increasing apparent toxicity. When testing different treatment schedules for the A431 tumor, we found that the regimen with radiotherapy (7.5 Gy single dose), given after the institution of SU11657 treatment, was more effective than radiotherapy preceding SU11657 treatment. Accordingly, we found that SU11657 markedly reduced intratumoral interstitial fluid pressure from 8.8 +/- 2.6 to 4.2 +/- 1.5 mm Hg after 1 day. Likewise, quantitative T2-weighed magnetic resonance imaging measurements showed that SU11657-treated mice had reduced intratumoral edema. Our data indicates that inhibition of Akt signaling by antiangiogenic treatment with SU11657 may result in: (a) normalization of tumor blood vessels that cause prerequisite physiologic conditions for subsequent radio/chemotherapy, and (b) direct resensitization of endothelial cells to radio/chemotherapy. We conclude that trimodal cancer therapy combining antiangiogenesis, chemotherapy, and radiotherapy has beneficial molecular and physiologic effects to emerge as a clinically relevant antitumor strategy.
Huber
Peter E
PE
Department of Radiation Oncology, German Cancer Research Center, University of Heidelberg Medical School, Heidelberg Germany. p.huber@dkfz.de
Bischof
Marc
M
Jenne
Jürgen
J
Heiland
Sabine
S
Peschke
Peter
P
Saffrich
Rainer
R
Gröne
Hermann-Josef
HJ
Debus
Jürgen
J
Lipson
Kenneth E
KE
Abdollahi
Amir
A
D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D002294:Carcinoma, Squamous Cell / Q000098:blood supply* / Q000188:drug therapy / Q000532:radiotherapy / Q000628:therapy*; D002465:Cell Movement / Q000187:drug effects / Q000528:radiation effects; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D003131:Combined Modality Therapy; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D005260:Female; D005493:Folic Acid Antagonists / Q000008:administration & dosage; D005971:Glutamates / Q000008:administration & dosage; D006147:Guanine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009930:Organic Chemicals / Q000008:administration & dosage; D000068437:Pemetrexed; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D023041:Xenograft Model Antitumor Assays
D020533:Angiogenesis Inhibitors; D000964:Antimetabolites, Antineoplastic; D005493:Folic Acid Antagonists; D005971:Glutamates; D009930:Organic Chemicals; D011518:Proto-Oncogene Proteins; C474557:SU 11657; D000068437:Pemetrexed; D006147:Guanine; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt