Asparagine synthetase (ASNS) Drives Tumorigenicity in Small Cell Lung Cancer

Objectives: Small cell lung cancer (SCLC) is an aggressive neuroendocrine carcinoma characterized by rapid proliferation, early metastasis, and limited therapeutic response. Metabolic reprogramming is increasingly recognized as a key feature of small cell lung cancer progression, yet the contribution of specific metabolic enzymes remains incompletely understood. This study aimed to investigate the role of asparagine synthetase in small cell lung cancer tumorigenicity and disease progression. Methods: Integrative analyses were performed using public transcriptomic datasets, proteomic profiling, and functional assays in vitro and in vivo. Asparagine synthetase expression levels were evaluated in normal lung, non-small cell lung cancer, and small cell lung cancer tissues using public microarray datasets. Loss of function studies were conducted using shRNA mediated knockdown in murine and human small cell lung cancer cell models. Tumor growth and survival were assessed using xenograft mouse models. Results: Asparagine synthetase expression was significantly elevated in small cell lung cancer compared with normal lung and non-small cell lung cancer tissues. Genetic depletion of asparagine synthetase impaired cellular proliferation and colony forming capacity in vitro. In vivo, asparagine synthetase knockdown suppressed tumor growth and was associated with prolonged survival in xenograft mouse models. Conclusions: These findings demonstrate that asparagine synthetase contributes to tumor growth and metabolic adaptability in small cell lung cancer. The results support a functional role for asparagine synthetase in malignant progression and suggest that targeting asparagine metabolism may represent a potential therapeutic approach in aggressive small cell lung cancer.