| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Reviews |
1 Institut National de la Sante et de la Recherche Medicale, U805, 2 Institut Gustave Roussy, 3 Institut National de la Sante et de la Recherche Medicale, U848, and 4 CIC BT507,Villejuif, France; 5 Université Paris XI, Le Kremlin Bicêtre, France; and 6 Département d'oncologie médicale, Centre Georges-François Leclerc, and 7 CRI Institut National de la Sante et de la Recherche Medicale 866 Faculté de Médecine, Dijon, France
Requests for reprints: Laurence Zitvogel, Institut National de la Sante et de la Recherche Medicale, U805, Institut Gustave Roussy, 39 rue Camille Desmoulins, F-94805 Villejuif, France. Phone: 33-1-42-11-50-41; Fax: 33-1-42-11-60-94; E-mail: zitvogel{at}igr.fr or Guido Kroemer, Institut National de la Sante et de la Recherche Medicale, U848. Phone: 33-1-42-11-60-46; Fax: 33-1-42-11-60-47; E-mail: kroemer{at}igr.fr.
| Abstract |
|---|
|
|
|---|
| Immune-Mediated Effects of Anticancer Treatments |
|---|
|
|
|---|
Nevertheless, the preclinical screening for new anticancer drugs still relies on human xenografts transplanted into immunodeficient mice. Although this approach is indeed relevant to study the cell-autonomous effects of anticancer agents, it completely overlooks any contribution of the host immune system to tumor eradication (4). To examine the implication of T cells in the success of chemotherapy or radiotherapy protocols, we compared the ability of a panel of anticancer treatments to promote tumor regression in immunodeficient versus competent mice. This strategy allowed us to identify therapeutic protocols in which tumor insult promotes adaptive immune responses (Fig. 1 ).
|
| High Mobility Group Box 1 Protein Binding on Toll-Like Receptor 4 Is Required for Crosspresentation of Tumor Antigens |
|---|
|
|
|---|
After ligand binding, TLR4 conveys intracellular signaling mainly via two adaptor proteins, Toll/IL-1R domain containing adaptor inducing IFNβ (TRIF; ref. 7) and myeloid differentiation primary response protein (MyD88; ref. 7). We therefore tested which among these adaptors would be involved in the antitumor efficacy of oxaliplatin against GOS. Oxaliplatin was efficient against GOS tumors established in wild-type or Trif–/– mice, yet failed to act against tumors growing in MyD88–/– hosts (9). Altogether, these data suggest that the TLR4/MyD88 pathway contributes to the success of anticancer therapy.
To unravel the molecular mechanisms underlying the immunogenicity of anticancer treatments in vivo, we screened the TLRs implicated in the immunogenicity of dying tumor cells. Dying EG7 cells (that are EL4 thymoma cells expressing OVA protein) injected into wild-type or tlr1-, 2-, 3-, 5-, 6-, 7-, and 9-deficient mice could elicit the priming of OVA-specific naïve T cells in vivo. However, no T-cell priming was observed when dying cells were injected into tlr4–/– mice, indicating that the immunogenicity of anthracyclines, X-ray, or oxaliplatin-treated tumor cells was dependent on TLR4 (9, 10). In line with these results, tlr4-deficient bone marrow–derived DCs were selectively impaired in their ability to present tumor antigens from dying tumor cells to T cells in conditions in which wild-type DC were able to do so. We subsequently verified in vivo that TLR4 dictated the crosspresentation of membrane-associated tumor antigens (but not soluble antigens) to T cells (Fig. 2 ; ref. 9).
|
Numerous endogenous danger signals ferried by dying tumor cells to innate immune effectors may account for the immunogenicity of tumor cell death (5, 8, 12). To identify the danger molecule(s) that contribute to the immunogenicity of dying tumor cells, we systematically compared the release of putative TLR4 ligands by live tumor cells, oxaliplatin-treated EG7 cells, or doxorubicin-treated CT26 cells. We found that high mobility group box 1 (HMGB1) molecules but not other known TLR4 ligands (including heat shock proteins, fibrinogen, fibronectin, and β-defensin 2) were selectively present in the supernatant of dying CT26 or EG7 tumors. These data suggested that the nuclear molecule HMGB1, which has been described to act as an alarmin (13), may determine the immunogenicity of dying tumor cells. The binding of HMGB1 to TLR4 was previously shown using fluorescence resonance energy transfer analyses and immunoprecipitation studies (14). To delineate the in vivo relevance of the interaction between TLR4 and HMGB1, we transfected CT26, EG7, and MCA205 fibrosarcoma cells with a siRNA designed to knockdown HMGB1. This manipulation revealed that the release of HMGB1 was mandatory for the priming of T cells by dying tumor cells. HMGB1 knockout also hampered the capacity of doxorubicin-treated CT26 tumor cells to confer protection against rechallenge with untreated tumor cells. Furthermore, a neutralizing antibody directed against HMGB1 blunted antigen presentation of tumor antigens from dying EG7 cells and inhibited T-cell priming elicited by dying EG7 cells in vivo (9). We concluded that the interaction of HMGB1 released by dying tumor cells with the TLR4 receptor present on DCs dictated the outcome of anticancer therapy. However, as addition of recombinant HMGB1 alone could not mimic the DC maturation induced by apoptotic tumor cells, we are currently searching for additional signals delivered by tumor cells to DCs that could contribute to efficient the T-cell differentiation and Th1 polarization.
| Clinical Relevance of TLR4 in the Response to Anthracyclines |
|---|
|
|
|---|
after lipopolysaccharide stimulation. By transfecting human HeLa cells (which express the normal form of TLR4) with a cDNA encoding the Asp299Gly allele of TLR4, we could show that the expression of the variant form of TLR4 significantly decreases the binding of recombinant HMGB1 to TLR4, as determined by coimmunoprecipitation (9). We further verified that the expression of TLR4 Asp299Gly in HeLa cells leads to impaired nuclear factor-
B activation after stimulation with recombinant HMGB1.8 Moreover, although monocyte-derived DCs (MD-DC) derived from normal individuals could crosspresent antigens from dying melanoma cells to CTL in an HMGB1-dependent manner, MD-DC from individuals bearing the TLR4 Asp299Gly mutation failed to do so (9). To investigate the clinical relevance of the TLR4 mutation for the response to anticancer treatments, we designed a retrospective cohort of 280 breast cancer patients presenting with lymph node involvement and treated with local radiotherapy and anthracycline-based adjuvant chemotherapy. We first genotyped the patients of this cohort by performing Taqman PCR analyses on blood DNA. The frequency of monoallelic expression of the Asp299Gly polymorphisms in this cohort was 17.1%. No significant difference for all classic prognostic factors (age, pathologic tumor size, lymph node involvement, tumor grade, hormone receptors, and median follow up) was noted between normal individuals and patients bearing the mutated tlr4 allele. However, metastasis-free survival was significantly decreased in women carrying the variant allele of tlr4 (50% of relapse in mutated versus 37.4% in nonmutated patients at 10 years; Log-rank test, P = 0.03; ref. 9). Altogether, this study identified the tlr4 mutation as an independent predictive factor for the success of anthracycline-based adjuvant regimen (Fig. 3 ).
|
| Prospects for the Clinical Use of Anticancer Compounds |
|---|
|
|
|---|
The data presented in this study question the current clinical management of cancer patients. For instance, high-dose glucocorticoids are commonly prescribed to treat some side effects of anticancer treatments such as vomiting. However, glucocorticoids are potent immunosuppressors (4). Thus, administrating such drugs to patients may annihilate the putative immunoadujuvant effect induced by anticancer agents. Similarly, it might be worth favoring neoadjuvant over adjuvant chemotherapy, as the former may lead to an increased delivery of tumor antigens resulting in an enhanced immune response against cancer. Finally, the functional relevance of the tlr4 SNP, which affects 10% of Caucasians, deserves further attention. We showed that chloroquine could correct deficient crosspresentation by TLR4-mutated mouse bone marrow DC or human TLR4 Asp299Gly MD-DC and that in tlr4–/– mice, chloroquine synergized with oxaliplatin. Furthermore, a clinical study on glioblastoma-bearing patients reported a benefit in adding chloroquine to conventional chemotherapy and radiotherapy (16). This suggests that combining choloroquine with conventional anticancer treatments may increase the chances of success of anticancer regimens, in particular in individuals bearing the tlr4 mutation. An alternate method to compensate for TLR4 deficiencies may rely on the administration of other TLR ligands to boost antitumor immune responses. Thus, we found that administration of specific ligands of TLR3 or TLR9 after irradiation could restore potent antitumor effects in tlr4-deficient mice (10). It is our hope that the clinical implementation of these therapeutic strategies will improve the efficacy of existing therapeutic regimens (17).
| Disclosure of Potential Conflicts of Interest |
|---|
|
|
|---|
| Acknowledgments |
|---|
| Footnotes |
|---|
Received 2/ 4/08. Accepted 2/ 6/08.
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
C. Denkert, S. Loibl, A. Noske, M. Roller, B. M. Muller, M. Komor, J. Budczies, S. Darb-Esfahani, R. Kronenwett, C. Hanusch, et al. Tumor-Associated Lymphocytes As an Independent Predictor of Response to Neoadjuvant Chemotherapy in Breast Cancer J. Clin. Oncol., January 1, 2010; 28(1): 105 - 113. [Abstract] [Full Text] [PDF] |
||||
![]() |
T.-G. Kim, C.-H. Kim, J.-S. Park, S.-D. Park, C. K. Kim, D.-S. Chung, and Y.-K. Hong Immunological Factors Relating to the Antitumor Effect of Temozolomide Chemoimmunotherapy in a Murine Glioma Model Clin. Vaccine Immunol., January 1, 2010; 17(1): 143 - 153. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.-G. Moon, W. Han, and D.-Y. Noh Underweight and Breast Cancer Recurrence and Death: A Report From the Korean Breast Cancer Society J. Clin. Oncol., December 10, 2009; 27(35): 5899 - 5905. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Corthay, K. U. Lundin, K. B. Lorvik, P. O. Hofgaard, and B. Bogen Secretion of Tumor-Specific Antigen by Myeloma Cells Is Required for Cancer Immunosurveillance by CD4+ T Cells Cancer Res., July 15, 2009; 69(14): 5901 - 5907. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. V. Shurin, I. L. Tourkova, R. Kaneno, and M. R. Shurin Chemotherapeutic Agents in Noncytotoxic Concentrations Increase Antigen Presentation by Dendritic Cells via an IL-12-Dependent Mechanism J. Immunol., July 1, 2009; 183(1): 137 - 144. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. A. J. O'Neill, C. E. Bryant, and S. L. Doyle Therapeutic Targeting of Toll-Like Receptors for Infectious and Inflammatory Diseases and Cancer Pharmacol. Rev., June 1, 2009; 61(2): 177 - 197. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. C. Prendergast Translational Research: Speeding New Concepts between Lab and Clinic Cancer Reviews Online Content, July 1, 2008; 2008(7): 13 - 14. [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Cancer Research | Clinical Cancer Research |
| Cancer Epidemiology Biomarkers & Prevention | Molecular Cancer Therapeutics |
| Molecular Cancer Research | Cancer Prevention Research |
| Cancer Prevention Journals Portal | Cancer Reviews Online |
| Annual Meeting Education Book | Meeting Abstracts Online |