Hiding in plain sight: NUT carcinoma is an unrecognized subtype of squamous cell carcinoma of the lungs and head and neck

Photodynamic therapeutic activity of novel porphyrins against lung squamous cell carcinoma

Porphyrins, as drug-food homologous bioactive substances, hold significant potential in nanomedicine research and photodynamic therapy (PDT). In this study, we synthesized two novel porphyrin compounds, PTA and PTBA, based on the porphyrin compound TCPP. Using these compounds, we prepared metal-porphyrin nanoparticles and evaluated their properties. Results from multiple assays demonstrated that both PTA and PTBA exhibited significantly enhanced photodynamic therapeutic activation under laser irradiation compared to TCPP. This included improved reactive oxygen species (ROS) and singlet oxygen release, as well as superior antitumor activity. When prepared as metal-porphyrin nanoparticles, all three compounds-PCN224 (TCPP with Zr⁴⁺), PMOF01 (PTA with Zr⁴⁺), and PMOF02 (PTBA with Zr⁴⁺)-showed significantly upregulated photodynamic therapeutic effects. These nanoparticles induced the accumulation of ROS and singlet oxygen in lung squamous cell carcinoma (LSCC) cells and demonstrated both in vitro and in vivo antitumor activity under laser irradiation. Notably, PMOF01 and PMOF02 exhibited much stronger antitumor effects compared to PCN224 in LSCC cells. Our findings highlight the photodynamic therapeutic potential of these novel porphyrin compounds and their nanoparticles. These results not only expand our understanding of porphyrins' antitumor capabilities but also provide new options for PDT applications.

Inhibition of RPA32 and Cytotoxic Effects of the Carnivorous Plant Sarracenia purpurea Root Extract in Non-Small-Cell Lung Cancer Cells

The carnivorous plant Sarracenia purpurea has been traditionally used in various ethnobotanical applications, including treatments for type 2 diabetes and tuberculosis-like symptoms. This study investigates the cytotoxic effects of S. purpurea root extract (Sp-R) on human non-small-cell lung cancer (NSCLC) cell lines, including H1975, H838, and A549, focusing on its impact on cell survival, apoptosis, proliferation, and migration. Additionally, its ability to inhibit the single-stranded DNA-binding activity of human RPA32 (huRPA32), a key protein in DNA replication, was evaluated. Extracts from different plant parts (leaf, stem, and root) were prepared using various solvents (water, methanol, ethanol, and acetone) and screened for apoptosis-inducing potential using the chromatin condensation assay. Among these, the acetone-extracted root fraction (Sp-R-A) exhibited the most potent pro-apoptotic effects. The MTT assay demonstrated a dose-dependent cytotoxic effect on NSCLC cells, with IC50 values of 33.74 μg/mL for H1975, 60.79 μg/mL for H838, and 66.52 μg/mL for A549. Migration and clonogenic assays further revealed that Sp-R-A significantly inhibited cancer cell migration and colony formation in a dose-dependent manner. Moreover, Sp-R-A enhanced apoptosis when combined with the EGFR inhibitor afatinib, suggesting a potential synergistic effect. The electrophoretic mobility shift assay confirmed that Sp-R-A significantly inhibited the DNA-binding activity of huRPA32, with an IC50 of 13.6 μg/mL. AlphaFold structural prediction and molecular docking studies indicated that major bioactive compounds in S. purpurea, including α-amyrin, ursolic acid, and betulinaldehyde, strongly interact with the DNA-binding domain of huRPA32, potentially contributing to its inhibitory effect. Overall, these findings suggest that huRPA32 is a potential molecular target of Sp-R-A and the anticancer potential of S. purpurea root extract against NSCLC is highlighted, supporting further investigation into its therapeutic applications.

PRAME Epitopes are T-Cell Immunovulnerabilities in BRD4::NUTM1 Initiated NUT Carcinoma

NUT carcinoma ("NC") is a rare but highly lethal solid tumor without an effective standard of care. NC is caused by bromodomain-containing NUTM1 fusion genes, most commonly BRD4::NUTM1 . BRD4::NUTM1 recruits p300 to acetylate H3K27 forming "megadomains" with the overexpression of encapsulated oncogenes, most notably MYC . Akin to MYC , we hypothesized that transcriptional dysregulation caused by BRD4::NUTM1 would lead to the generation of cancer specific antigens that could be therapeutically actionable. Integrating genomics, immunopeptidomics, and computational biology approaches, we identified PRAME as the predominantly transcribed and HLA Class I-presented cancer/testis antigen in NC. Further, we show that a PRAME epitope-specific T-cell receptor ("TCR") x CD3 activator bispecific molecule modeled after brenetafusp has potent T-cell mediated activity against PRAME+ NC. Our results show that PRAME is often highly expressed in NC due to BRD4::NUTM1, and that BRD4::NUTM1 induced PRAME antigens are promising TCR targets for forthcoming clinical trials in NC.

Statement of Significance

NC is one of the most aggressive solid tumors to afflict humans and is refractory to chemotherapy, T-cell checkpoint blockade, and targeted therapies. We show PRAME epitopes are promising targets for TCR-based therapeutics like brenetafusp in NC, adding to growing momentum for addressing challenging fusion malignancies with TCR therapeutics.