Project description:The general purpose of the experiment is to compare the therapeutic effect of photon (X) radiotherapy versus proton (P) therapy for head and neck carcinoma. For that purpose we have generated cells that have resisted to multi irradiations by X or P. We have then injected these human cells in nude mice. Whereas these cells proliferate less than the control (0, non-irradiated cells) in vitro, they formed bigger tumors in mice compared to 0 cells. Hence, the hypothesis is that they secreted factors that educate the microenvironment. We have observed that although the tumors generated by the P cells are as big as those generated by the X cells, the lymphangiogenic/metastatic capacity is greater for the X cells. Hence, we would like to compare within a whole transcriptomic screening the RNA from 0, X and P tumors. The provided samples consist of a mix of human and mouse RNA.
Project description:Subcutaneous A431 tumors in the right hind limb of NCr nu/nu mice were treated with 5 daily fractions of external beam radiotherapy (2 Gy photon or 1 Gy carbon per fraction), a single fraction of 7.2 MBq 131Iodine-labelled Cetuximab intravenously or a combination of the two. Untreated tumors served as controls. Mice were sacrificed and tumor tissue collected for expression profiling 5 days after endoradiotherapy of 1 week after the last fraction of external beam radiotherapy.
Project description:Subcutaneous B16F10 tumors in the right hind limb of C57BL/6 mice were treated with 5 daily fractions of external beam radiotherapy (8 Gy photon or 5 Gy carbon per fraction), a single fraction of 13.3 MBq 131Iodine-labelled benzamide-derivative MIP-1145 intravenously or a combination of the two. Untreated tumors served as controls. Mice were sacrificed and tumor tissue collected for expression profiling 5 days after endoradiotherapy of 1 week after the last fraction of external beam radiotherapy.
Project description:Novel particle therapy was implemented into standard-of-care for cancer patients during the last years. However, experimental studies investigating cellular and molecular mechanisms are lacking although prognostic biomarker are urgently needed. The cancer stem cell (CSC)-related marker aldehyde dehydrogenase (ALDH) is known to impact on prostate cancer radiosensitivity through affecting defense against reactive oxygen species (ROS), reducing DNA damage repair and increasing cell survival. Surprisingly, we could show in a previous study that ionizing radiation itself enriches for ALDH-positive CSCs in a time- and dose-dependent manner through alteration in histone methylation. Within the present study, we investigated CSC marker dynamics upon proton beam irradiation and hypothesized that this novel particle therapy may have increased CSC targeting potential due to its increased ionization potential compared to conventional photon irradiation. However, we found that proton irradiation is affecting cellular dynamics and escape from cell death.
Project description:Novel particle therapy was implemented into standard-of-care for cancer patients during the last years. However, experimental studies investigating cellular and molecular mechanisms are lacking although prognostic biomarker are urgently needed. The cancer stem cell (CSC)-related marker aldehyde dehydrogenase (ALDH) is known to impact on prostate cancer radiosensitivity through affecting defense against reactive oxygen species (ROS), reducing DNA damage repair and increasing cell survival. Surprisingly, we could show in a previous study that ionizing radiation itself enriches for ALDH-positive CSCs in a time- and dose-dependent manner through alteration in histone methylation. Within the present study, we investigated CSC marker dynamics upon proton beam irradiation and hypothesized that this novel particle therapy may have increased CSC targeting potential due to its increased ionization potential compared to conventional photon irradiation. However, we found that proton irradiation is affecting cellular dynamics and escape from cell death.
Project description:The tyrosine kinase ErbB2 positive breast tumors have more aggressive tumor growth, poorer clinical outcome, and more resistance to radiotherapy, chemotherapy and hormone therapy. A humanized anti-ErbB2 monoclonal antibody Herceptin and a small molecules inhibitor Lapatinib were developed and approved by FDA to treat patients with ErbB2 amplification and overexpression. Unfortunately, most ErbB2+ breast cancers do not respond to Herceptin and Lapatinib, and the majority of responders become resistant within 12 months of initial therapy (defined as secondary drug resistance). Such differences in response to Lapatinib treatment is contributed by substantial heterogeneity within ErbB2+ breast cancers. To address this possibility, we carried out transcriptomic analysis of mammary tumors from genetically diverse MMTV-ErbB2 mice. This will help us to have a better understanding of the heterogeneous response to ErbB2 targeted therapy and permit us to design better and more individualized (personalized) treatment strategies for human ErbB2 positive breast cancer. 214 MMTV-ErbB2 mammary tumors and 8 normal mammary glands were analyzed by Affymetrix microarrays.
Project description:Radiotherapy can act as in situ vaccine activating preventive tumor-specific immune responses in treated patients. While carbon ion radiotherapy holds superior biophysical properties over conventional photon irradiation, little is known about the immunological effects induced by this radiation type. Multiple strategies combining radiotherapy with immune checkpoint inhibition (radioimmunotherapy) to enhance anti-tumor immunity have been described, however, results on the immune cell composition in tumors following radioimmunotherapy with carbon ions are lacking. Here, we present a bilateral tumor model based on time-shifted transplantation of murine, Her2+ EO771 tumor cells onto the flanks of immune competent mice followed by selective irradiation of the primal tumor. αCTLA4- but not αPD-L1-based radioimmunotherapy induced complete tumor rejection and mediated eradication of even non-irradiated, distant tumors. Cured mice were protected against EO771 rechallenge indicative of long lasting, tumor-specific immunological memory. Single cell RNA-sequencing and flow cytometric analyses of irradiated tumors revealed activation of NK cells and distinct tumor-associated macrophage clusters with upregulated expression of TNF and IL1 responsive genes. Distant tumors of irradiated mice showed higher frequencies of naïve T cells, which were activated upon combination with CTLA4 blockade. Thus, radioimmunotherapy with carbon ions plus CTLA4 inhibition reshapes the tumor-infiltrating immune cell composition and can induce complete rejection even of non-irradiated tumors. Our data suggest to combine radiotherapy approaches with CTLA4 blockade to achieve durable anti-tumor immunity. Furthermore, evaluation of future radioimmunotherapy approaches should not be restricted to immunological impacts at the irradiation site, but should also consider systemic immunological effects on non-irradiated tumors.
Project description:Immune checkpoint blockade is a powerful oncologic treatment modality for a wide variety of human malignancies. Randomized clinical trials are assessing how best to interdigitate this treatment modality with traditional therapies including radiotherapy. A challenge in oncology is to rationally and effectively integrate immunotherapy with traditional modalities including radiotherapy. Here, we demonstrate that radiotherapy induces tumor cell ferroptosis. Ferroptosis agonists augment and ferroptosis antagonists limit radiotherapy efficacy in tumor models. Immunotherapy sensitizes tumors to radiotherapy by promoting tumor cell ferroptosis. Mechanistically, IFN derived from immunotherapy-activated CD8+ T cells and radiotherapy-activated ATM independently, yet synergistically repress SLC7A11, a unit of the glutamate-cystine antiporter xc-, resulting in reduced cystine uptake, enhanced tumor lipid oxidation and ferroptosis, and improved tumor control. Thus, ferroptosis is an unappreciated mechanism and focus for the development of effective combinatorial cancer therapy.
Project description:Abstract: Transplanted tumors in syngeneic mice treated with immune checkpoint blockade and radiotherapy demonstrate synergy and an abscopal effect. Indeed, tumors generated from sarcoma cell lines transplanted into syngeneic mice are cured by PD-1 blockade and radiotherapy, but autochthonous, primary sarcomas from the same high mutational load model are resistant to the identical treatment. Here, we generated a single cell atlas of tumor-infiltrating immune cells from allograft and primary tumors, which demonstrates marked differences in their immune landscapes before and after radiation and immunotherapy. Allograft tumors are enriched for effector CD8+ T cells that mediate response to combination therapy, but the immune response to primary sarcomas shows tumor-specific tolerance. Genetic barcoding of primary tumors reveals a cellular response to combination therapy, but resistance of specific clones. Together, this comprehensive comparison of the primary and allograft tumor microenvironments identifies immune tolerance and clonal resistance to immunotherapy and radiotherapy specific to primary tumors.
Project description:Proton irradiation is touted for its improved tumor targeting due to the physical advantages of ion beams for radiotherapy. Recent studies from our laboratory have shown that, in addition to targeting advantages, proton irradiation can inhibit angiogenic and immune factors and thereby modulate tumor progression. High-energy protons also constitute a principal component of the galactic cosmic rays to which astronauts are exposed. Increased understanding of the biological effects of proton exposure would thus contribute to both improved cancer therapy and carcinogenesis risk assessment for space travel. In addition, age plays a major role in tumor incidence and is a critical consideration for estimating cancer risk. We investigated the effects of host age and proton exposure on tumor progression. Tumor lag time and growth dynamics were tracked following injection of murine Lewis lung carcinoma (LLC) cells into young (68 day) versus old (736 day) mice with or without coincident irradiation. Tumor progression was suppressed in old compared to young mice. Differences in progression were further modulated by proton irradiation (1GeV), with increased inhibition evident in old mice. Through global transcriptome analysis, TGFβ1 and TGFβ2 were determined to be key players that contributed to the tumor dynamics observed. These findings point to older hosts providing decreased systemic tumor support, which can be further inhibited by proton irradiation.