Biology subjects

Bussink, J.

Publications and source records attributed to Bussink, J..

4 recordsLinked to original sources

bioRxiv2026

CAIX-targeted α therapy directed against hypoxic tumor cells in combination with immune checkpoint inhibitors in a syngeneic mouse tumor model

Tumor hypoxia is a major factor in therapy resistance. A potential strategy to treat hypoxic tumors is targeted therapy (TAT), since particles can cause complex DNA damage independent of oxygen levels. Here, we investigate the potential of TAT as monotherapy and in combination with immune checkpoint inhibitors (ICI) to treat hypoxic tumors. MethodsMonoclonal anti-CAIX antibody DOTA-MSC3 was labeled with indium-111 (111In) or actinium-225 (225Ac), and binding to CAIX-expressing hypoxic tumor cells was determined in vitro. Subsequently, the in vivo biodistribution and dosimetry of radiolabeled DOTA-MSC3 was assessed in B16F10-OVA tumor-bearing mice, and its spatial distribution in the tumor (autoradiography) was correlated to CAIX expression measured by immunofluorescence. Finally, tumor growth and survival were determined upon treatment with [225Ac]Ac-DOTA-MSC3 with and without ICI. Results111In- and 225Ac-labeled DOTA-MSC3 bound specifically to CAIX-expressing hypoxic tumor cells. In vivo, uptake of both radiopharmaceuticals in B16F10-OVA tumors was spatially correlated with CAIX-positive hypoxic tumor regions. [225Ac]Ac-DOTA-MSC3 significantly prolonged survival of mice compared with PBS control (p=0.0032). Furthermore, the combination of [225Ac]Ac-DOTA-MSC3 and ICI significantly delayed tumor growth and prolonged survival compared with PBS control (p=0.0022 and p=0.0019, respectively). ConclusionOverall, these results demonstrate first proof-of-concept of the potential of CAIX-TAT to treat hypoxic tumors by targeting CAIX-positive hypoxic tumor regions. CAIX-TAT combined with ICI was most effective in inhibiting tumor growth and prolonging survival of tumor-bearing mice. Future studies are required to investigate the radiobiological and immunological effects of CAIX-TAT, to guide optimization of this treatment in combination with ICI.

cancer biology↗

bioRxiv2024

Head-to-head comparison of nuclear imaging approaches to quantify tumor CD8+ T-cell infiltration

Many immunotherapies focus on (re)invigorating CD8+ T cell anti-cancer responses and different nuclear imaging techniques have been developed to measure CD8+ T cell distributions. In vivo labeling approaches using radiotracers primarily show CD8+ T cell distributions, while ex vivo labeled CD8+ T cells can show CD8+ T cell migration patterns, homing, and tumor infiltration. Currently, a comprehensive head-to-head comparison of in vivo and ex-vivo cell labeling with respect to their tumor and normal tissue targeting properties and correlation to the presence of CD8+ T cells is lacking, yet essential for correct interpretation of clinical CD8+ imaging applications. Therefore, we performed a head-to-head comparison of three different CD8+ T cell imaging approaches: 1) 89Zr-labeled DFO-conjugated Fc-silent anti-CD8 antibody ([89Zr]Zr-anti-CD8-IgG2asilent), 2) ex vivo 89Zr-oxine labeled ovalbumin-specific CD8+ T cells ([89Zr]Zr-OT-I cells), and 3) 18F-labeled IL2 ([18F]AlF-RESCA-IL2). MethodsB16F10/OVA tumor-bearing C57BL/6 mice (n=10/group) received intravenously one of the three radiopharmaceuticals. PET/CT images were acquired starting 72 h ([89Zr]Zr-anti-CD8-IgG2asilent), 24 and 48 h ([89Zr]Zr-OT-I cells), and 10 min ([18F]AlF-RESCA-IL2) post injection. Subsequently, ex vivo biodistribution analysis of the radiopharmaceuticals was performed followed by flow cytometric analysis to evaluate the number of intratumoral CD8+ T cells. Additionally, the intratumoral radiolabel distributions was assessed by autoradiography and immunohistochemistry (IHC) on tumor slices. Results[89Zr]Zr-anti-CD8-IgG2asilent, [89Zr]Zr-OT-I cells, and [18F]AlF-RESCA-IL2 showed uptake in CD8-rich tissues, with preferential targeting to the spleen. Biodistribution analysis showed tumor uptake above blood level for all radiopharmaceuticals, except [18F]AlF-RESCA-IL2. For all three approaches, the uptake in the tumor-draining lymph node was significantly higher compared with the contralateral axial lymph node, suggesting that all approaches allow evaluation of immune responses involving CD8+ T cells. Tumor uptake of [89Zr]Zr-anti-CD8-IgG2asilent (R2=0.65, p<0.01) and [89Zr]Zr-OT-I cells (R2=0.74, p<0.01) correlated to the number of intratumoral CD8+ T cells (flow cytometry). The intratumoral distribution pattern of the radiosignal was different for ex vivo and in vivo radiolabeling techniques. The short half-life of 18F precluded autoradiography assessment of [18F]AlF-RESCA-IL2. ConclusionWe show that [89Zr]Zr-anti-CD8-IgG2asilent and [89Zr]Zr-OT-I cells PET/CT imaging can be used to evaluate intratumoral CD8+ T cells, even though their normal tissues and intratumoral distribution patterns are significantly different. Based on their characteristics, [89Zr]Zr-anti-CD8-IgG2asilent might be most useful to immunophenotyping the TME, while the ex vivo cell labeling approach visualizes CD8+ T cell migrations patterns and the permissiveness of tumors for invasion, whereas [18F]AlF-RESCA-IL2 allows for rapid recurrent imaging and might prove useful for tracking rapid changes in CD8+ T cell distributions. In conclusion, our head-to-head comparison of the three prototype CD8+ T cell labeling approaches provides new insights which can aid in correct interpretation of clinical CD8 imaging and may guide in the selection of the optimal imaging approach for the research question of interest.

immunology↗

bioRxiv2024

Towards Effective CAIX-targeted Radionuclide and Checkpoint Inhibition Combination Therapy for Advanced Clear Cell Renal Cell Carcinoma

BackgroundImmune checkpoint inhibitors (ICI) are routinely used in advanced clear cell renal cell carcinoma (ccRCC). However, a substantial group of patients does not respond to ICI therapy. Radiation is a promising approach to increase ICI response rates since it can generate anti-tumor immunity. Targeted radionuclide therapy (TRT) is a systemic radiation treatment, ideally suited for precision irradiation of metastasized cancer. Therefore, the aim of this study is to explore the potential of combined TRT, targeting carbonic anhydrase IX (CAIX) which is overexpressed in ccRCC, using [177Lu]Lu-DOTA-hG250, and ICI for the treatment of ccRCC. MethodsIn this study, we evaluated the therapeutic and immunological action of [177Lu]Lu-DOTA-hG250 combined with aPD-1/a-CTLA-4 ICI. First, the biodistribution of [177Lu]Lu-DOTA-hG250 was investigated in BALB/cAnNRj mice bearing Renca-CAIX or CT26-CAIX tumors. Renca-CAIX and CT26-CAIX tumors are characterized by poor versus extensive T-cell infiltration and homogeneous versus heterogeneous PD-L1 expression, respectively. Tumor-absorbed radiation doses were estimated through dosimetry. Subsequently, [177Lu]Lu-DOTA-hG250 TRT efficacy with and without ICI was evaluated by monitoring tumor growth and survival. Therapy-induced changes in the tumor microenvironment were studied by collection of tumor tissue before and 5 or 8 days after treatment and analyzed by immunohistochemistry, flow cytometry, and RNA profiling. ResultsBiodistribution studies showed high tumor uptake of [177Lu]Lu-DOTA-hG250 in both tumor models. Dose escalation therapy studies in Renca-CAIX tumor-bearing mice demonstrated dose-dependent anti-tumor efficacy of [177Lu]Lu-DOTA-hG250 and remarkable therapeutic synergy including complete remissions when a presumed subtherapeutic TRT dose (4 MBq, which had no significant efficacy as monotherapy) was combined with aPD-1+aCTLA-4. Similar results were obtained in the CT26-CAIX model for 4 MBq [177Lu]Lu-DOTA-hG250 + a-PD1. Ex vivo analyses of treated tumors revealed DNA damage, T-cell infiltration, and modulated immune signaling pathways in the TME after combination treatment. ConclusionsSubtherapeutic [177Lu]Lu-DOTA-hG250 combined with ICI showed superior therapeutic outcome and significantly altered the TME. Our results underline the importance of investigating this combination treatment for patients with advanced ccRCC in a clinical setting. Further investigations should focus on how the combination therapy should be optimally applied in the future. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=169 SRC="FIGDIR/small/580614v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@6a4825org.highwire.dtl.DTLVardef@1a6acbeorg.highwire.dtl.DTLVardef@1970976org.highwire.dtl.DTLVardef@ee4bd3_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2023

Signalling-state dependent drug-tolerance in head and neck squamous cell carcinoma.

Intratumor heterogeneity negatively impacts therapeutic response and patient prognosis. Besides the established role of genetic heterogeneity, non-genetic mechanisms of persistence to drug treatment are emerging. Here, we characterise cells selected for their persistence to control, epidermal growth factor inhibition (EGFRi), radiation and combined treatment from low passage head and neck squamous cell carcinoma (HNSCC) cultures. Using a panel of 70 (phospho-)specific DNA-conjugated antibodies we measured activities of 8 signalling pathways, self-renewal, differentiation, DNA damage and cell-cycle, in conjunction with the transcriptional output in single cells, using our RNA and Immuno-Detection (RAID) technology. Six recurrent transcriptional programs reflecting processes including proliferation, differentiation and metabolic activity, as well as protein-based signalling-states, were associated with drug persistence, while copy number variation inference indicated involvement of non-genetic tolerance mechanisms. Projecting RNA velocity onto the antibody-derived signalling-states suggested a key role for integrin-mediated focal-adhesion signalling in drug-persistence in our cell system. Using machine-learning we derived a core transcriptional signature connected to adhesion-based drug-persistence, which was predictive of poor prognosis in a TGCA HNSCC cohort (hazard-ratio 1.87, p<10-5). Furthermore, functional analyses confirmed that cells expressing high levels of integrin alpha-6 (ITGA6) were tolerant to EGFRi treatment, and that forcing cells out of this cell-state through transient targeted inhibition of Focal Adhesion Kinase activity re-instated EGFRi sensitivity in drug persistent cells. Taken together, our single-cell multi-omics analysis identified an actionable adhesion-signalling mediated cell-state driving drug tolerance in HNSCC.

systems biology↗