Phospholipase D1 overexpression drives metabolic survival and stress resistance in cervical cancer

Background: Cervical squamous cell carcinoma (SCC) and adenocarcinoma (ADC) are clinically and biologically distinct subtypes, yet the metabolic drivers of SCC aggressiveness remain poorly understood. Phospholipase D1 (PLD1), a lipid-modifying enzyme involved in oncogenic signaling and cancer metabolism, has been reported to be elevated in various malignancies. However, its subtype-specific expression pattern and functional relevance in cervical cancer have not been clearly delineated. Methods: PLD1 expression was evaluated using TCGA datasets and validated in primary cervical tumors by qRT-PCR, PLD activity assays, and immunohistochemistry. Functional studies were performed in primary SCC and ADC cells using shRNA-mediated PLD1 knockdown or a PLD1-selective inhibitor. Apoptosis, ATP levels, glycolytic activity, clonogenic survival, and invasion were measured under basal and metabolic stress conditions. Results: PLD1 was significantly overexpressed in SCC compared with ADC at the mRNA, protein, and enzymatic activity levels. PLD1 inhibition markedly decreased SCC cell survival, whereas ADC cells exhibited minimal sensitivity. PLD1 blockade reduced glycolytic flux and ATP production and increased apoptosis under serum starvation, glucose restriction, and hypoxia. PLD1 knockdown also impaired clonogenic survival and suppressed invasion. These effects were further enhanced by co-treatment with the glycolysis inhibitor 2-deoxy-D-glucose, highlighting a strong dependency of SCC cells on PLD1-mediated metabolic regulation. Conclusions: PLD1 is selectively upregulated in cervical SCC and serves as a key regulator of glycolysis, energy homeostasis, and adaptation to metabolic stress. The pronounced metabolic dependence on PLD1 identifies it as a promising therapeutic target in SCC, and PLD1 inhibition may effectively exploit metabolic vulnerabilities unique to this tumor subtype.