Implication of CCNG1 in radiosensitivity via the Wnt/β-catenin pathway in esophageal squamous cells

Abstract

Esophageal cancer (EC) poses a substantial threat to human health. The development of radioresistance in esophageal cancer cells is a critical factor contributing to local treatment failure and an unfavorable prognosis in affected patients. A comprehensive analysis was performed using bulk RNA sequencing (RNA-seq) and single-cell RNA sequencing (scRNA-seq) data from esophageal squamous cell carcinoma (ESCC) samples. Radioresistant ESCC cell lines were generated to explore the functional role of CCNG1. Various techniques, including gene knockdown, flow cytometry, and apoptosis assays, were utilized to evaluate alterations in radiosensitivity, cell cycle progression, and cell survival in response to CCNG1 modulation. Elevated CCNG1 expression was associated with poor clinical outcomes in ESCC patients and contributed to various malignant phenotypes in ESCC cells. In radioresistant ESCC cell lines, CCNG1 knockdown markedly increased radiosensitivity, as demonstrated by enhanced G2/M phase arrest and apoptosis following radiation exposure. CellChat analysis indicated a correlation between CCNG1 and the Wnt/β-catenin signaling pathway, while western blot (WB) analysis confirmed that CCNG1 functions as a downstream effector of Wnt/βcatenin. Our study has identified CCNG1 as a key regulator of radiosensitivity in ESCC, mediated through its interaction with the Wnt/β-catenin signaling pathway. Targeting the Wnt/β-catenin/ CCNG1 axis presents a promising therapeutic strategy to enhance the efficacy of radiotherapy in ESCC, potentially overcoming radioresistance and improving patient outcomes.Keywords CCNG1, Esophageal squamous cell carcinoma (ESCC), Radioresistance, Wnt/β-catenin pathway Esophageal cancer (EC) is a malignant tumor that originates from the epithelial lining of the esophagus 1 . It ranks 11th among all malignant tumors in terms of incidence, accounting for approximately 3% of all cancer cases. In terms of mortality, EC ranks 7th, with a grim 5-year survival rate of just 20% 2,3 . According to data from the Global Cancer Observatory (GLOBOCAN) in 2022, there were 510,716 new cases of esophageal cancer and 445,129 deaths worldwide, underscoring its substantial global health burden 2 . Notably, esophageal squamous cell carcinoma (ESCC) constitutes approximately 85% of all esophageal cancer cases 4 .Radiotherapy (RT) plays a critical role in the comprehensive treatment of ESCC, particularly in the form of concurrent chemoradiotherapy, which is the standard of care for patients with inoperable esophageal cancer 5,6 . RT can not only be used for the direct killing of tumor cells for therapeutic purposes, but also for palliative treatment of terminal-stage patients to improve their quality of life 7 . Furthermore, RT combined with immunotherapy yields better survival outcomes than immunotherapy alone in patients with stage II or more advanced esophageal cancer 8 . However, tumor heterogeneity often results in radioresistance, undermining the effectiveness of RT 9 . The mechanisms underlying radioresistance in ESCC...