DNA-protein crosslinks (DPCs), formed by the covalent conjugation of proteins to DNA, are toxic lesions that interfere with DNA metabolic processing and transcription. The development of an accurate biochemical assay for DPC isolation is a priority for the mechanistic understanding of their repair. Here, we propose the STAR assay for the direct quantification of DPCs, sensitive to physiologically relevant treatment conditions. Implementing the STAR assay revealed the formation of small cross-linked peptides on DNA, created by the proteolytic degradation of DPCs by SPRTN. The initial proteolytic degradation of DPCs is required for the downstream activation of DNA repair, which is mediated through the phosphorylation of H2Ax. This leads to the accumulation of DNA repair factors on chromatin and the subsequent complete removal of the cross-linked peptides. These results confirmed that the repair of DPCs is a two-step process, starting with proteolytic resection by SPRTN, followed by the repair of the underlying damage to the DNA.

Nerolidol is a naturally occurring sesquiterpene alcohol with multiple properties, including antioxidant, antibacterial, and antiparasitic activities. A few studies investigating the antitumor properties of nerolidol have shown positive results in both cell culture and mouse models. In this study, we investigated the antitumor mechanism of cis-nerolidol in bladder carcinoma cell lines. The results of our experiments on two bladder carcinoma cell lines revealed that nerolidol inhibited cell proliferation and induced two distinct cell death pathways. We confirmed that cis-nerolidol induces DNA damage and ER stress. A mechanistic study identified a common cAMP, Ca²⁺, and MAPK axis involved in signal propagation and amplification, leading to ER stress. Inhibition of any part of this signaling cascade prevented both cell death pathways. The two cell death mechanisms can be distinguished by the involvement of caspases. The early occurring cell death pathway is characterized by membrane blebbing and cell swelling followed by membrane rupture, which can be prevented by the inhibition of caspase activation. In the late cell death pathway, which was found to be caspase-independent, cytoplasmic vacuolization and changes in cell shape were observed. cis-Nerolidol shows promising antitumor activity through an unorthodox mechanism of action that could help target resistant forms of malignancies, such as bladder cancer.

Histones are an essential part of nucleosomes that regulate chromatin structure and function. Histone exchanges and modifications represent a scaffold for DNA transcription, repair, and replication. Studying histones and histone code is an important and fast-developing branch of epigenetic science. Here we propose a fast, efficient, and versatile assay for nucleosomal histone isolation from mammalian cells, without the use of acids or high salt solutions which are common for other histone isolation techniques. All components used in the protocol are common and inexpensive laboratory chemicals. The protocol has been evaluated on six commonly used cell lines and two animal tissue samples. The mild extraction conditions preserve delicate histone epigenetic changes, allowing its downstream analyses. We have demonstrated the assays’ successful application during changes in the transcriptional activity of histone genes, cell cycle transitions, and DNA-damaging conditions. Histone fractions, obtained by the protocol, can be used for further applications, such as electrophoresis, immunoblot, and mass spectrometry. Therefore, the new proposed nucleosomal histone isolation method is sensitive, specific, and suitable for downstream applications of various kinds.

Background: Non-small cell lung cancer (NSCLC) harboring activating epidermal growth factor receptor (EGFR) mutations has undergone a therapeutic paradigm shift with the introduction of third-generation EGFR tyrosine kinase inhibitors (TKIs), particularly osimertinib. Despite these advances, disseminated disease remains challenging, and treatment selection for cytotoxic chemotherapy is still largely guideline-driven rather than individualized. Functional chemosensitivity testing using liquid biopsy-derived tumor cells represents an emerging strategy to personalize systemic therapy beyond molecular profiling alone. In addition, consolidative stereotactic ablative body radiotherapy (SABR) may enhance durable disease control after systemic response. Case Description: We report the case of a 75-year-old woman diagnosed with stage IV disseminated lung adenocarcinoma involving mediastinal, cervical, and hilar lymph nodes, pleura, and bone. Molecular analysis revealed an EGFR exon 19 deletion, low programmed death-ligand 1 (PD-L1) expression (1%), and no other actionable alterations. A liquid biopsy-based chemosensitivity assay demonstrated marked tumor cell susceptibility to oxaliplatin and pemetrexed, guiding selection of a non-standard chemotherapy regimen. The patient received six cycles of oxaliplatin-pemetrexed in combination with continuous osimertinib (80 mg daily). Interim positron emission tomography combined with computed tomography (PET/CT) imaging showed near-complete metabolic regression of systemic disease. Residual activity within the primary lung lesion was subsequently treated with SABR, resulting in complete radiographic and metabolic remission. At 1-year follow-up, the patient remains disease-free on maintenance osimertinib alone, with minimal toxicity and preserved performance status. Conclusions: This case illustrates the potential clinical value of integrating functional chemosensitivity testing with targeted therapy and consolidative SABR in disseminated EGFR-mutated NSCLC. Personalized chemotherapy selection based on tumor-specific drug responsiveness, rather than guideline-driven regimens alone, may contribute to exceptional treatment responses. These findings support further investigation of functional precision oncology approaches to optimize outcomes in advanced lung cancer.