Jianhua Gong

The small‐molecule pyridazinone derivative IMB5036 (IMB) exhibits significant cytotoxicity against multiple cancer cell lines, and KH‐type splicing regulatory protein (KSRP) is confirmed as its direct binding partner. However, KSRP's functional role in neuroblastoma (NB) and the mechanism mediating IMB's antitumor effects remain unclear. This study analyzed public tumor databases and found KSRP expression negatively correlates with NB patients' median survival. Experiments showed IMB induces NB cell pyroptosis, immunogenic cell death (ICD, with calreticulin exposure), and cGAS‐STING activation (to boost antitumor immunity), while CRISPR‐Cas9‐mediated KSRP knockout notably attenuates these effects. Transcriptome sequencing further confirmed KSRP mediates IMB's regulation of HSPA6/RSAD2. This study clarifies KSRP‐dependent ICD drives NB antitumor immunity, providing a basis for KSRP‐targeted NB immunotherapies.

Glypican-2 (GPC2), a member of the GPC gene family, primarily functions in developing neural and thyroid cancer tissues, exerting influence on protein transduction, cellular proliferation and differentiation, as well as oncogenic signatures. GPC2 exhibits significant overexpression in the majority of neuroblastoma (NB) samples while remaining nearly undetectable in normal pediatric tissue samples. Overall survival (OS) was employed as a key parameter to investigate the correlation between GPC2 expression and pan-pediatric cancers. To assess the association between GPC2 expression and clinical parameters of NB, box plots followed by t-tests were utilized. Protein-protein interaction (PPI) networks and gene-gene interaction networks were constructed. Functional roles were determined through Ontology (GO) term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The XCell was employed to analyze the relationship between GPC2 expression and immune-related cells. Additionally, we retrospectively collected clinical data and survival information from a cohort of 51 patients diagnosed with NB and conducted immunohistochemistry (IHC) on the specimens as a validation set. A significant correlation between elevated GPC2 expression and reduced survival rates was observed in NB and brain tumors (P < 0.05). Notably, high GPC2 expression showed a non-significant trend toward reduced survival in four other pediatric tumor types except osteosarcoma. Notably, the MYCN amplified group exhibited significantly higher levels of GPC2 expression. Furthermore, GPC2 expression showed a positive correlation with infiltrating basophils, CD4 T cells, CD8 T cells, CD8 naïve T cells, Tgd cells, Th1 cells, Th2 cells and pro B cells, while demonstrating a negative correlation with infiltrating fibroblasts, macrophages M1 and M2 subtypes, monocytes neutrophils and pDCs. Among all 51 pediatric NB patients analyzed in this study, the MYCN amplified group displayed significantly higher levels of GPC2 expression compared to the MYCN not-amplified group. Additionally, survival analysis revealed that individuals with high GPC2 expression had significantly worse OS compared to those with low expression (P = 0.018). Elevated GPC2 expression was significantly correlated with reduced survival rates in NB and brain tumors (P < 0.05), with a non-significant trend toward reduced OS in four other pediatric tumor types. Furthermore, the expression level of GPC2 in NB showed a positive association with MYCN status and levels of immune cell infiltration The online version contains supplementary material available at 10.1186/s12885-026-15820-x.

Seizure-related 6 homologue (SEZ6) is a highly expressed transmembrane protein that has emerged as a promising therapeutic target for small-cell lung cancer (SCLC). In this study, we developed a novel immuno-positron emission tomography probe ([⁶⁴Cu]Cu-NOTA-GGB02-F9) based on the SEZ6-targeting antibody, GGB02-F9, for use in preclinical mouse models of SCLC. The diagnostic potential of [⁶⁴Cu]Cu-NOTA-GGB02-F9 was evaluated in preclinical SCLC models with varying levels of SEZ6 expression. The H69 tumors exhibited a distinct accumulation of tracer uptake in the tumor xenograft mice, reaching a maximum uptake at 72 h postinjection, which was significantly higher than that in the H69 GGB02-F9-blocked and H460 groups (P < 0.01) at 24, 48, and 72 h postinjection. The uptake of the tumor tracer in mice was found to be associated with SEZ6 expression, as determined by immunohistochemical analysis. Our study demonstrated that [⁶⁴Cu]Cu-NOTA-GGB02-F9 can noninvasively evaluate SEZ6 expression in preclinical SCLC mouse models.

Disialoganglioside GD2 (GD2) is highly expressed in several tumors. While anti-GD2 antibodies and GD2-based antibody-drug conjugates (ADCs) have shown some therapeutic efficacy, their activity requires enhancement. Elastase, abundant in tumor microenvironment, has substrates that can serve as ADC linkers. Here, we constructed an anti-GD2 ADC by conjugating the anti-GD2 antibody Hu3F8 to the payload monomethyl auristatin E (MMAE) via an elastase-cleavable tetrapeptide linker (BMOA). Hu3F8 was produced using a 293F expression system, and its specific binding to GD2-positive cells was confirmed. The cytotoxicity of the ADCs was evaluated in both GD2-positive and GD2-negative tumor cell lines with or without elastase and its antitumor effects were investigated. It showed GD2-dependent cytotoxicity, with a significantly decreased IC₅₀ in GD2-positive cells upon elastase addition, while no cytotoxicity was observed in GD2-negative cells. Additionally, Hu3F8-BMOA-MMAE induced significant cell cycle arrest and apoptosis in GD2-positive cells, with stronger effects in the presence of elastase. In M21 melanoma mouse models, Hu3F8-BMOA-MMAE achieved an obvious tumor inhibition rate compared to the control. These findings demonstrate that utilizing a neutrophil elastase tetrapeptide substrate as a linker in anti-GD2 ADCs is a potential strategy for the therapy of GD2-positive tumors.

Relapsed and refractory high-risk neuroblastoma (NBL) patients have limited treatment options and a poor prognosis, highlighting the urgent need for novel targeted therapies. This study evaluates the GD2-targeting PET imaging agent [89Zr]Zr-DFO-hu3F8 and the radioimmunotherapy agent [225Ac]Ac-DOTA-hu3F8 in NBL animal models. The GD2 overexpressing IMR32 tumor was assessed by using [89Zr]Zr-DFO-hu3F8 PET imaging to confirm targeting efficacy. The safety and therapeutic efficacy of [225Ac]Ac-DOTA-hu3F8 were evaluated in GD2-positive NBL xenografts. ImmunoPET revealed the high and sustained uptake of [89Zr]Zr-DFO-hu3F8 in IMR32 tumors compared to the [89Zr]Zr-DFO-IgG control group. In vitro biodistribution analysis showed that a tumor uptake was 58.47 ± 3.64%ID/g at 168 h post-injection. A single dose of [225Ac]Ac-DOTA-hu3F8 treatment significantly suppressed tumor growth, with most tumors (4/5) achieving complete remission at medium and high doses (11.1 and 18.5 kBq). Overall, our findings demonstrate that alpha-targeted therapy based on hu3F8 holds significant potential as a promising curative treatment strategy for NBL.

Purpose Neuroblastoma (NB) is a malignant embryonic tumour with poor prognosis and high mortality rate. The antigen gisialoganglioside (GD2), which is highly expressed on the surface of NB cells, is an effective target for therapy. This study aims to evaluate the GD2 expression with [⁶⁴Cu]Cu-NOTA-hu3F8 positron emission tomography (PET) imaging and explore the radioimmunotherapy (RIT) effect of [¹⁷⁷Lu]Lu-DOTA-hu3F8 in NB tumour models. Methods The in vitro validation of the binding ability of anti-GD2 humanised monoclonal antibody (hu3F8) to GD2 was achieved via flow cytometry, cell immunofluorescence, and cell uptake test. Hu3F8 were conjugated with p-SCN-Bn-NOTA (NOTA) and p-SCN-Bn-DOTA (DOTA) for ⁶⁴Cu- and ¹⁷⁷Lu- radiolabelling. PET imaging and RIT studies were conducted using [⁶⁴Cu]Cu-NOTA-hu3F8 and [¹⁷⁷Lu]Lu-DOTA-hu3F8 in subcutaneous NB tumour models. Results The Institute for Medical Research-32 (IMR32) cell line exhibited a specific binding ability of hu3F8. PET imaging demonstrated a specific accumulation of [⁶⁴Cu]Cu-NOTA-hu3F8 in IMR32 tumour models, with a maximum tumour uptake of 23.73 ± 2.29%ID/g (n = 3) at 72 h post-injection (p.i.), outperforming other groups significantly (P < 0.001). The high dose [¹⁷⁷Lu]Lu-DOTA-hu3F8 group (11.1MBq) showed the most potent tumour suppression, with a standardised tumour volume of about 20.47 ± 6.32% at 30 days p.i., significantly smaller than other groups (n = 5, P < 0.05). Conclusion This study demonstrated that ⁶⁴Cu-/¹⁷⁷Lu- labelled hu3F8 could noninvasively evaluate the GD2 expression and effectively inhibit tumour growth in NB tumour models. The excellent therapeutic efficacy of [¹⁷⁷Lu]Lu-DOTA-hu3F8 may be helpful for the clinical translation of this GD2-targeted theranostics approach in GD2-positive tumours.

Purpose CD30 serves as an ideal therapeutic target for lymphoma, but its variable expression and high relapse rate pose challenges in targeted therapy. This study aims to label the anti-CD30 monoclonal antibody with ⁶⁴Cu/¹⁷⁷Lu for immuno-positron emission tomography (immuno-PET) and radioimmunotherapy (RIT). Methods CD30 binding kinetics of anti-CD30-IgG (IMB16) were measured by Biolayer interferometry (BLI). Western blotting screened lymphoma cell lines for CD30 expression. Flow cytometry and immunofluorescence validated the specific binding of IMB16. IMB16 was conjugated to p-SCN-Bn-NOTA(NOTA) and p-SCN-Bn-DOTA(DOTA) for radiolabeling with ⁶⁴Cu and ¹⁷⁷Lu. [⁶⁴Cu]Cu-NOTA-IMB16 and [¹⁷⁷Lu]Lu-DOTA-IMB16 were used for immuno-PET and RIT in subcutaneous lymphoma NSG mouse models. Results IMB16 had a strong binding affinity to CD30 according to the BLI. Western blotting revealed high CD30 expression in Karpas299 cells and negative expression in Raji cells. Flow cytometry and immunofluorescence confirmed specific binding of IMB16 to CD30 on cell surface. Radiochemical purity of [⁶⁴Cu]Cu-NOTA-IMB16 and [¹⁷⁷Lu]Lu-DOTA-IMB16 exceeded 95%. In Immuno-PET imaging, CD30-positive Karpas299 tumours had a mean uptake value of 19.2 ± 0.9%ID/g (n = 3) at 24 h post-injection, significantly higher than Karpas299-blocked and Raji-negative groups (P < 0.001). A high radiation dose (300µCi) of [¹⁷⁷Lu]Lu-DOTA-IMB16 significantly inhibited tumour growth (80.2 ± 17.6% standardized tumour volume, n = 5) at 10 days post-injection, compared to controls. Ex vivo biodistribution and histological staining supported in vivo PET imaging and RIT results. Conclusions Labelling IMB16 with ⁶⁴Cu enabled non-invasive assessment of CD30 expression, while ¹⁷⁷Lu labelling effectively suppressed tumour growth in CD30-positive lymphoma. CD30-targeted theranostic show promise for patient stratification and treatment enhancement, warranting further clinical evaluation.