Immuno-PET imaging of PD-L1 expression in patient-derived lung cancer xenografts with [68Ga]Ga-NOTA-Nb109

The value of predicting the invasiveness and degree of infiltration of pulmonary ground-glass nodules based on computed tomography features and enhanced quantitative analysis

Background

The incidence and mortality rate of lung cancer are the highest in the world among all malignant tumors. Accurate assessment of ground-glass nodules (GGNs) is crucial in reducing lung cancer mortality. This study aimed to explore the value of computed tomography (CT) features and quantitative parameters in predicting the invasiveness and degree of infiltration of GGNs.

Methods

Lesions were classified into three groups based on pathological types: the precursor glandular lesion (PGL) group, including atypical adenomatoid hyperplasia and adenocarcinoma in situ; the minimally invasive adenocarcinoma group; and the invasive adenocarcinoma group. Quantitative and qualitative data of the nodules were compared, and receiver operating characteristic (ROC) curve analysis was performed for each quantitative parameter. Binary logistic regression analysis was used to evaluate independent predictors of GGN invasiveness.

Results

There were significant differences in lesion size, morphology, nodule type, bronchial abnormality, internal vascular sign and pleural retraction among the three groups (P<0.05). There were significant differences in all CT quantitative parameters (CT attenuation value in the plain phase, CT attenuation value in the arterial phase, CT attenuation value in the venous phase, arterial phase enhancement difference, venous phase enhancement difference, arterial phase enhancement index and venous phase enhancement index) among the three groups (P<0.001). The ROC curve analysis showed that the CT attenuation value in the plain phase, CT attenuation value in each enhanced phase, enhancement difference and enhancement index had good discriminatory power. Binary logistic regression analysis revealed that nodule type and internal vascular sign were independent risk factors for GGN invasiveness.

Conclusions

CT features combined with enhanced scanning and quantitative analysis have important value in predicting the invasiveness of GGNs. The type of pulmonary nodule detected on CT (pure GGN or mixed GGN) and the presence of internal vascular signs are independent risk factors for GGN invasiveness.

Advancements in nuclear imaging using radiolabeled nanobody tracers to support cancer immunotherapy

The evolving landscape of cancer immunotherapy has revolutionized cancer treatment. However, the dynamic tumor microenvironment has led to variable clinical outcomes, indicating a need for predictive biomarkers. Noninvasive nuclear imaging, using radiolabeled modalities, has aided in patient selection and monitoring of their treatment response. This approach holds promise for improving diagnostic accuracy, providing a more personalized treatment regimen, and enhancing the clinical response. Nanobodies or single-domain antibodies, derived from camelid heavy-chain antibodies, allow early timepoint detection of targets with high target-to-background ratios. To date, a plethora of nanobodies have been developed for nuclear imaging of tumor-specific antigens, immune checkpoints, and immune cells, both at a preclinical and clinical level. This review comprehensively outlines the recent advancements in nanobody-based nuclear imaging, both on preclinical and clinical levels. Additionally, the impact and expected future advancements on the use of nanobody-based radiopharmaceuticals in supporting cancer diagnosis and treatment follow-up are discussed.

Promising Combinatorial Therapeutic Strategies against Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) presents a complex and diverse disease, exhibiting variations at individuals' cellular and histological levels. This complexity gives rise to different subtypes and genetic mutations, posing challenges for accurate diagnosis and effective treatment. Nevertheless, continuous progress in medical research and therapies is continually shaping the landscape of NSCLC diagnosis and management. The treatment of NSCLC has undergone significant advancements in recent years, especially with the emergence of targeted therapies that have shown remarkable efficacy in patients with actionable mutations. This has ushered in the era of personalized medicine in NSCLC treatment, with improvements in molecular and immunohistochemical techniques contributing to enhanced progression-free survival. This review focuses on the latest progress, challenges, and future directions in developing targeted therapies for NSCLC, including tyrosine kinase inhibitors (TKIs), DNA-damaging agents, immunotherapy regimens, natural drug therapy, and nanobodies. Furthermore, recent randomized studies have demonstrated enhanced overall survival in patients receiving different targeted and natural drug therapies.

Navigating the landscape of PD-1/PD-L1 imaging tracers: from challenges to opportunities

Immunotherapy targeted to immune checkpoint inhibitors, such as the program cell death receptor (PD-1) and its ligand (PD-L1), has revolutionized cancer treatment. However, it is now well-known that PD-1/PD-L1 immunotherapy response is inconsistent among patients. The current challenge is to customize treatment regimens per patient, which could be possible if the PD-1/PD-L1 expression and dynamic landscape are known. With positron emission tomography (PET) imaging, it is possible to image these immune targets non-invasively and system-wide during therapy. A successful PET imaging tracer should meet specific criteria concerning target affinity, specificity, clearance rate and target-specific uptake, to name a few. The structural profile of such a tracer will define its properties and can be used to optimize tracers in development and design new ones. Currently, a range of PD-1/PD-L1-targeting PET tracers are available from different molecular categories that have shown impressive preclinical and clinical results, each with its own advantages and disadvantages. This review will provide an overview of current PET tracers targeting the PD-1/PD-L1 axis. Antibody, peptide, and antibody fragment tracers will be discussed with respect to their molecular characteristics and binding properties and ways to optimize them.

In vitro and in vivo study on the treatment of non-small cell lung cancer with radionuclide labeled PD-L1 nanobody

PURPOSE

Nanobodies have become promising carriers due to excellent in vivo properties. Radiopharmaceutical therapy targeting programmed cell death ligand 1 (PD-L1) is an effective therapeutic strategy. Our study aimed to explore therapeutic efficacy of 131I labeled PD-L1 nanobody (Nb109) in non-small cell lung cancers (NSCLCs) in vitro and in vivo.

METHODS

131I-Nb109 was synthesized by chloramine-T method. We implemented stability analysis, SDS-PAGE and lipid-water partition coefficient test to assess its quality. Cell uptake assay and SPECT/CT scan were applied to evaluate its ability to target NSCLCs (H460 and A549). CCK8 assay and in vivo efficacy assay were conducted to estimate its therapeutic effect in H460 tumors. Damage-associated molecular patterns (DAMPs) release in H460 cells incubated with 131I-Nb109 was investigated by western blot and ATP test kit.

RESULTS

131I-Nb109 was hydrophilic with high labeling rate (69.51-98.06%), radiochemical purity (99.17% ± 0.76%) and stability. Cell uptake experiments showed that H460 cells (PD-L1 positive) compared with A549 cells (PD-L1 negative) had higher 131I-Nb109 uptake. SPECT/CT imaging revealed the accumulation of 131I-Nb109 in H460 tumor within 48 h. 131I-Nb109 inhibited H460 tumor growth without toxic side effects in contrast with control group. It also induced H460 cells to release DAMPs (adenosine triphosphate, high mobility group box 1, and heat shock protein 70).

CONCLUSION

131I-Nb109 had high stability, excellent ability to target and treatment PD-L1 positive tumors, and can improve tumor immunogenicity. The results of our study were expected to inspire the development of more novel radiopharmaceuticals to treat NSCLCs.

Positron Emission Tomography Probes for Imaging Cytotoxic Immune Cells

Non-invasive positron emission tomography (PET) imaging of immune cells is a powerful approach for monitoring the dynamics of immune cells in response to immunotherapy. Despite the clinical success of many immunotherapeutic agents, their clinical efficacy is limited to a subgroup of patients. Conventional imaging, as well as analysis of tissue biopsies and blood samples do not reflect the complex interaction between tumour and immune cells. Consequently, PET probes are being developed to capture the dynamics of such interactions, which may improve patient stratification and treatment evaluation. The clinical efficacy of cancer immunotherapy relies on both the infiltration and function of cytotoxic immune cells at the tumour site. Thus, various immune biomarkers have been investigated as potential targets for PET imaging of immune response. Herein, we provide an overview of the most recent developments in PET imaging of immune response, including the radiosynthesis approaches employed in their development.

Non-apoptotic activity of the mitochondrial protein SMAC/Diablo in lung cancer: Novel target to disrupt survival, inflammation, and immunosuppression

Mitochondrial SMAC/Diablo induces apoptosis by binding the inhibitor of apoptosis proteins (IAPs), thereby activating caspases and, subsequently, apoptosis. Previously, we found that despite its pro-apoptotic activity, SMAC/Diablo is overexpressed in cancer, and demonstrated that in cancer it possesses new essential and non-apoptotic functions that are associated with regulating phospholipid synthesis including modulating mitochondrial phosphatidylserine decarboxylase activity. Here, we demonstrate additional functions for SMAC/Diablo associated with inflammation and immunity. CRISPR/Cas9 SMAC/Diablo-depleted A549 lung cancer cells displayed inhibited cell proliferation and migration. Proteomics analysis of these cells revealed altered expression of proteins associated with lipids synthesis and signaling, vesicular transport and trafficking, metabolism, epigenetics, the extracellular matrix, cell signaling, and neutrophil-mediated immunity. SMAC-KO A549 cell-showed inhibited tumor growth and proliferation and activated apoptosis. The small SMAC-depleted “tumor” showed a morphology of alveoli-like structures, reversed epithelial-mesenchymal transition, and altered tumor microenvironment. The SMAC-lacking tumor showed reduced expression of inflammation-related proteins such as NF-kB and TNF-α, and of the PD-L1, associated with immune system suppression. These results suggest that SMAC is involved in multiple processes that are essential for tumor growth and progression. Thus, targeting SMAC’s non-canonical function is a potential strategy to treat cancer.