Antibodies

Background: DNA–protein interactions form crucial intermolecular systems in biological processes such as transcriptional regulation. The best-known DNA–protein interactions typically involve double-stranded DNA, but single-stranded DNA–binding proteins (SSBs) also exist in nature. Moreover, there are protein-binding DNA aptamers: artificially created single-stranded DNA molecules obtained through in vitro selection to target specific proteins. However, little research has used in vitro selection to identify proteins that recognize the tertiary structure formed by single-stranded DNA. Most research has focused on using DNA libraries for in vitro selection of target proteins. Methods: In this study, we performed in vitro selection using the cDNA display method and a VHH library of single-domain antibodies to determine the tertiary structure of a DNA aptamer that binds to the antibiotic oxytetracycline (OTC). We also used AlphaFold to predict the binding of VHH to DNA aptamers. Results: Our results suggest that the interaction depends on the aptamer’s structural characteristics. While relatively high association rates were observed regardless of the presence or absence of OTC, the dissociation rate was lower in the OTC (+) condition. Conclusions: These findings suggest that there may be proteins that recognize the tertiary structure of nucleic acids, in addition to those that bind to double-stranded DNA.

Background: Onconeural antigens expressed by tumor cells may trigger the production of onconeural antibodies, which result in paraneoplastic neurological syndromes (PNS). Objectives: We investigated the presence of eight onconeural antibodies (amphiphysin, CRMP5, Nova/Ri, Cdr2/Yo, Elav/Hu, Zic4, Ma2, recoverin) and neurologic symptoms and signs in 33 metastatic renal cell carcinoma patients who started first-line therapy. Overall survival (OS) and time to treatment failure (TTF) were also determined. Methods: Sera were tested on a dot blot of purified, recombinant, human onconeural antigens. Neurologic symptoms were reviewed by a questionnaire, and signs were determined by a dedicated neurologist. OS and TTF of patients were determined by Kaplan–Meier analysis. Results: 51% of patients (17 of 33) harbored at least one onconeural antibody, 36% of patients had multiple antibodies. Two patients with cerebellar signs and three patients with signs of polyneuropathy had onconeural antibodies, suggesting a definite PNS. Six additional patients with polyneuropathy and without onconeural antibodies might have possible PNS. OS was significantly longer in patients harboring the anti-Hu antibody (n = 14) compared to those without it (n = 19) (median survival was 745 and 135 weeks, respectively). Conclusions: We have found that the occurrence of onconeural antibodies is relatively high in metastatic RCC, not reported previously. A significant percentage of these patients have neurological symptoms with a probable paraneoplastic background, which may have a detrimental impact on their quality of life. Anti-Hu antibody was identified most frequently. Our preliminary data show that the presence of anti-Hu antibody correlates with better prognosis and survival, suggesting the beneficial role of activated autoimmunity. In the era of frontline immune checkpoint inhibitor (ICI) therapy of RCC, it would be strongly encouraged to further explore the prognostic and potentially predictive role of anti-Hu antibody.

Bone is the most common site of distant relapse in breast cancer, and skeletal-related events (SREs) remain a major source of morbidity and reduced quality of life in patients with bone-metastatic disease. Denosumab, a fully human IgG2 monoclonal antibody against receptor activator of nuclear factor-κB ligand (RANKL), interrupts osteoclast-driven bone resorption upstream of the bisphosphonate mechanism of action and has demonstrated superiority over zoledronic acid in preventing SREs in pivotal phase III trials. Beyond this well-established antiresorptive role, RANK/RANKL signaling has been implicated in mammary tumorigenesis and modulation of the tumor immune microenvironment, and recent window-of-opportunity studies have shown that short-term denosumab increases tumor-infiltrating lymphocytes in human breast tumors—a translational finding that has not yet been linked to a demonstrated clinical benefit. This narrative review synthesizes the pharmacology of denosumab; the biological rationale linking RANKL to immune-cell function in the breast; the pivotal and contemporary clinical evidence in metastatic and early breast cancer, including the divergent D-CARE and ABCSG-18 adjuvant trials and the 2026 REDUSE dosing-interval data; and practical considerations distinguishing denosumab’s evidentiary position in metastatic disease, cancer treatment-induced bone loss, and adjuvant disease modification. We also discuss why preclinical immune synergy has not been reproduced clinically and outline priorities for biomarker-selected trials, immunotherapy combinations, dose de-escalation, and MRONJ risk stratification. Throughout, we distinguish established clinical applications from translational and hypothesis-generating findings, and highlight methodological limitations—including small subgroup sizes, retrospective design, and unpublished congress data—that should temper interpretation of several recent findings before they inform clinical practice or future trial design.