Silencing the Expression of Cyclin G1 Enhances the Radiosensitivity of Hepatocellular Carcinoma In Vitro and In Vivo by Inducing Apoptosis

Radiosensitization Strategies for Hepatocellular Carcinoma: Mechanisms, Therapeutic Advances, and Clinical Perspectives

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, with treatment efficacy limited by late-stage diagnosis, frequent recurrence, and therapeutic resistance. Radiotherapy is a key local treatment for HCC; however, its efficacy is frequently limited by intrinsic tumor radioresistance. This review discusses strategies to improve the therapeutic response of HCC to radiotherapy. Targeting DNA repair mechanisms can block tumor cells from recovering after radiation-induced damage, whereas modulating cell cycle arrest and programmed cell death pathways (e.g., apoptosis, autophagy) diminishes their survival capacity. Furthermore, remodeling the tumor microenvironment-through hypoxia alleviation, metabolic reprogramming, oxidative stress regulation, and immune activation-may potentiate radiotherapy efficacy. Technological advances, such as stereotactic body radiotherapy and nanomaterial-based approaches, have also improved the precision and effectiveness of radiotherapy. Clinically, combining radiotherapy with systemic therapies (e.g., immune checkpoint inhibitors and antiangiogenic agents) has demonstrated preliminary promise in enhancing treatment outcomes. However, translating preclinical findings into clinical practice remains challenging due to tumor heterogeneity, normal tissue toxicity, and the lack of predictive biomarkers for treatment selection. Future research should focus on integrating molecular profiling with multimodal therapies to enable personalized radiosensitization and bridge the gap between mechanistic insights and clinical outcomes.

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

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/β-catenin. 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.

MiR-122 radiosensitize hepatocellular carcinoma cells by suppressing cyclin G1

PURPOSE

Emerging evidence has shown that radiotherapy is an effective treatment for hepatocellular carcinoma (HCC), Micro(mi)RNAs are involved in regulating radiosensitivity in many cancers. MiR-122 accounts for approximately 70% of all cloned miRNAs in the liver, but there are few reports about whether it is involved in regulating of radiosensitivity in HCC cells.

MATERIALS AND METHODS

HCC cells (HepG2 and Huh7) overexpressing miR-122 were constructed by transfecting them with lentiviral-miR-122. Then, their proliferation ability was analyzed by the MTT, and colony formation assays and a xenograft tumor model was used to detect their radiosensitivity. The expression of cyclin G1 mRNA and protein was detected by the quantitative real-time polymerase chain reaction and western blotting, respectively.

RESULTS

Overexpression of miR-122 inhibited the proliferation of, and radiosensitized HCC cells. Cyclin G1 mRNA and protein level were suppressed in HepG2 tumors overexpression miR-122.

CONCLUSION

MiR-122 may be useful as a potential radiosensitizer for HCC, and its mechanism is related to the regulation of cyclin G1.