Evaluation of tyrosine kinase inhibitor combinations for glioblastoma therapy.
Glioblastoma multiforme (GBM) is the most common intracranial cancer but despite recent advances in therapy the overall survival remains about 20 months. Whole genome exon sequencing studies implicate mutations in the receptor tyrosine kinase pathways (RTK) for driving tumor growth in over 80% of GB...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2012-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3462750?pdf=render |
| _version_ | 1819017872983195648 |
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| author | Avadhut D Joshi Watcharin Loilome I-Mei Siu Betty Tyler Gary L Gallia Gregory J Riggins |
| author_facet | Avadhut D Joshi Watcharin Loilome I-Mei Siu Betty Tyler Gary L Gallia Gregory J Riggins |
| author_sort | Avadhut D Joshi |
| collection | DOAJ |
| description | Glioblastoma multiforme (GBM) is the most common intracranial cancer but despite recent advances in therapy the overall survival remains about 20 months. Whole genome exon sequencing studies implicate mutations in the receptor tyrosine kinase pathways (RTK) for driving tumor growth in over 80% of GBMs. In spite of various RTKs being mutated or altered in the majority of GBMs, clinical studies have not been able to demonstrate efficacy of molecular targeted therapies using tyrosine kinase inhibitors in GBMs. Activation of multiple downstream signaling pathways has been implicated as a possible means by which inhibition of a single RTK has been ineffective in GBM. In this study, we sought a combination of approved drugs that would inhibit in vitro and in vivo growth of GBM oncospheres. A combination consisting of gefitinib and sunitinib acted synergistically in inhibiting growth of GBM oncospheres in vitro. Sunitinib was the only RTK inhibitor that could induce apoptosis in GBM cells. However, the in vivo efficacy testing of the gefitinib and sunitinib combination in an EGFR amplified/PTEN wild type GBM xenograft model revealed that gefitinib alone could significantly improve survival in animals whereas sunitinib did not show any survival benefit. Subsequent testing of the same drug combination in a different syngeneic glioma model that lacked EGFR amplification but was more susceptible to sunitinib in vitro demonstrated no survival benefit when treated with gefitinib or sunitinib or the gefitinib and sunitinib combination. Although a modest survival benefit was obtained in one of two animal models with EGFR amplification due to gefitinib alone, the addition of sunitinib, to test our best in vitro combination therapy, did not translate to any additional in vivo benefit. Improved targeted therapies, with drug properties favorable to intracranial tumors, are likely required to form effective drug combinations for GBM. |
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| format | Article |
| id | doaj.art-c939725f70114000a2a0d0b2b91dba90 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-21T03:10:26Z |
| publishDate | 2012-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-c939725f70114000a2a0d0b2b91dba902022-12-21T19:18:00ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-01710e4437210.1371/journal.pone.0044372Evaluation of tyrosine kinase inhibitor combinations for glioblastoma therapy.Avadhut D JoshiWatcharin LoilomeI-Mei SiuBetty TylerGary L GalliaGregory J RigginsGlioblastoma multiforme (GBM) is the most common intracranial cancer but despite recent advances in therapy the overall survival remains about 20 months. Whole genome exon sequencing studies implicate mutations in the receptor tyrosine kinase pathways (RTK) for driving tumor growth in over 80% of GBMs. In spite of various RTKs being mutated or altered in the majority of GBMs, clinical studies have not been able to demonstrate efficacy of molecular targeted therapies using tyrosine kinase inhibitors in GBMs. Activation of multiple downstream signaling pathways has been implicated as a possible means by which inhibition of a single RTK has been ineffective in GBM. In this study, we sought a combination of approved drugs that would inhibit in vitro and in vivo growth of GBM oncospheres. A combination consisting of gefitinib and sunitinib acted synergistically in inhibiting growth of GBM oncospheres in vitro. Sunitinib was the only RTK inhibitor that could induce apoptosis in GBM cells. However, the in vivo efficacy testing of the gefitinib and sunitinib combination in an EGFR amplified/PTEN wild type GBM xenograft model revealed that gefitinib alone could significantly improve survival in animals whereas sunitinib did not show any survival benefit. Subsequent testing of the same drug combination in a different syngeneic glioma model that lacked EGFR amplification but was more susceptible to sunitinib in vitro demonstrated no survival benefit when treated with gefitinib or sunitinib or the gefitinib and sunitinib combination. Although a modest survival benefit was obtained in one of two animal models with EGFR amplification due to gefitinib alone, the addition of sunitinib, to test our best in vitro combination therapy, did not translate to any additional in vivo benefit. Improved targeted therapies, with drug properties favorable to intracranial tumors, are likely required to form effective drug combinations for GBM.http://europepmc.org/articles/PMC3462750?pdf=render |
| spellingShingle | Avadhut D Joshi Watcharin Loilome I-Mei Siu Betty Tyler Gary L Gallia Gregory J Riggins Evaluation of tyrosine kinase inhibitor combinations for glioblastoma therapy. PLoS ONE |
| title | Evaluation of tyrosine kinase inhibitor combinations for glioblastoma therapy. |
| title_full | Evaluation of tyrosine kinase inhibitor combinations for glioblastoma therapy. |
| title_fullStr | Evaluation of tyrosine kinase inhibitor combinations for glioblastoma therapy. |
| title_full_unstemmed | Evaluation of tyrosine kinase inhibitor combinations for glioblastoma therapy. |
| title_short | Evaluation of tyrosine kinase inhibitor combinations for glioblastoma therapy. |
| title_sort | evaluation of tyrosine kinase inhibitor combinations for glioblastoma therapy |
| url | http://europepmc.org/articles/PMC3462750?pdf=render |
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