Targeting Temozolomide‐Resistant Glioblastoma: Therapeutic Potential of Neuronal Nitric Oxide Synthase Inhibitor

BACKGROUND AND PURPOSE: The treatment of glioblastoma remains a major clinical challenge, largely due to intrinsic and acquired resistance to Temozolomide (TMZ). We aim to advance a novel therapeutic approach to overcome TMZ resistance in human glioblastoma by using the neuronal nitric oxide synthase inhibitor BA-101 as both a monotherapy and an adjuvant therapy. This approach leverages the additive anti-cancer activity of BA-101 to enhance the efficacy of TMZ and thereby improve treatment outcomes for glioblastoma patients. EXPERIMENTAL APPROACH: We used TMZ-resistant human glioblastoma LN-18 and LN-229 cells to study the therapeutic potential and additive anticancer activity of nNOS inhibitor BA-101 using in vitro cancer functional assays, including cell proliferation, cell invasion, and migration assays, and biochemical assessment of biomarkers for nitrosative stress, and apoptosis using western blot analysis, flow cytometry and AnnexinV/PI staining. We further performed an in vivo preclinical evaluation using an LN-229 xenograft tumor model in SCID mice. KEY RESULTS: Our findings demonstrate that BA-101 displays significant anti-cancer activity and sensitizes resistant glioblastoma cells to TMZ, reducing nitrosative stress, inhibiting clonogenic growth, invasion and migration, and promoting apoptotic cell death. It also demonstrates a significant decrease in tumor volume, suggesting that BA-101 exerts additive anti-tumor activity when used as an adjuvant to TMZ in SCID mice bearing LN 229 xenografts. CONCLUSIONS AND IMPLICATIONS: Collectively, our findings strongly suggest that BA-101 has potential for further preclinical and translational development as an anticancer agent and a novel TMZ chemosensitizer for GBM therapy.