DNA–histone H1 complex (DNA-H1 complex)

The DNA–histone H1 complex is a fundamental structural unit of chromatin, consisting of the linker histone H1 bound to the DNA between nucleosomal cores (Source: UniProt P07305). Under normal physiological conditions, this complex is sequestered within the nucleus of viable cells and is protected by the plasma membrane, making it inaccessible to circulating antibodies. However, in the necrotic regions of solid tumors—where cells have lost membrane integrity due to hypoxia or nutrient deprivation—the DNA–histone H1 complex becomes exposed to the extracellular environment (Source: PubMed PMID 2143435). This unique accessibility is the basis for Tumor Necrosis Therapy (TNT), which utilizes monoclonal antibodies like chTNT-1/B to target these universal nuclear antigens (Source: PubMed PMID 15501366). By conjugating these antibodies with radioisotopes such as Iodine-131 (e.g., Cotara), clinicians can deliver targeted radiation directly to the core of a tumor. This approach effectively kills surrounding viable cancer cells through a bystander effect while minimizing damage to healthy, intact tissues (Source: ClinicalTrials.gov NCT00004080, PubMed PMID 10631004).

Other names

Histone H1-DNA complexNecrotic cell DNA-histone complexTNT-1 targetNuclear matrix antigenNecrotic tumor DNA-histone complex

Targeted radioimmunotherapy where monoclonal antibodies bind to exposed nuclear antigens in necrotic tumor regions, delivering ionizing radiation to kill adjacent viable tumor cells via the bystander effect.