Human Cell
·
2025
·Vol. 38
·期 3
·1-14
·
IF 3.1
Zhu Xiao-Yu,Li Pi-Song,Qu Hui,Ai Xing,Zhao Zi-Ting,He Jia-Bei
Radiotherapy resistance, is usually caused by enhanced tumor stemness and poses a significant challenge in treating breast cancer (BRCA). In this study, we investigated the molecular regulatory mechanism of radiotherapy sensitivity in BRCA associated with replication factor C4 (RFC4) and insulin-like growth factor 2 mRNA binding protein 2 mRNA Binding Protein 2 (IGF2BP2). RFC4 expression was increased in BRCA cell lines and tissues, and high RFC4 expression in BRCA patients predicted the occurrence of lymphatic metastasis. RFC4-specific short hairpin RNA sequences or RFC4 coding sequences were subsequently cloned and inserted into plasmid vectors to downregulate or upregulate RFC4 expression. Knockdown of RFC4 attenuated stemness, as evidenced by a reduction in sphere formation and the downregulation of CD44 and SOX2. RFC4 silencing inhibited migration and invasion, promoted apoptosis, and improved sensitivity to radiotherapy (4-Gy X-ray). The results were detected by a wound healing assay, a transwell assay, and flow cytometry. The overexpression of RFC4 had the opposite effect on BRCA cells. Like RFC4 expression, IGF2BP2 expression was also increased in the cancer tissues of breast cancer patients. The results of the dual luciferase assay and RIP assay confirmed the binding of IGF2BP2 to the RFC4 mRNA coding sequence. Knockdown of RFC4 eliminated the effects of IGF2BP2 overexpression on increasing cell viability, invasion, the expression of stemness markers and radioresistance, suggesting that the effect of RFC4 on the stemness of BRCA cells was regulated by IGF2BP2. In conclusion, we reported that RFC4, a key regulator of BRCA progression, promoted radioresistance in BRCA and was positively regulated by IGF2BP2.
研究领域:
肿瘤学
·
分子生物学
·
医学
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PubMed
高影响因子
CELL BIOLOGY INTERNATIONAL
·
2026
·Vol. 50
·期 2
·e70136
·
IF 3.1
Guansheng Hu,Laiai Fang,Xiang Ding,Qingjun Zeng,Youwu Wen,Dongyang Cheng,Yonggui Zhou
Replication factor C (RFC), a multimeric protein with ATPase activity, plays a crucial role in DNA replication and repair. RFC4, one of its subunits, is aberrantly expressed in various malignant tumors, including colorectal cancer (CRC). Nevertheless, the impact of RFC4 on CRC metastasis remains to be elucidated. In this study, we systematically examined the effects of RFC4 silencing on the proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and Wnt/β-catenin signaling pathway in CRC cells in vitro. Additionally, we further explored the regulatory role of RFC4 in liver metastasis of CRC cells in vivo. Finally, BML-284, a known activator of the Wnt/β-catenin signaling pathway, was employed to validate the underlying mechanism by which RFC4 modulates the invasive phenotype of CRC cells. The results demonstrated that RFC4 was significantly overexpressed in CRC cell lines. Upon silencing of RFC4, the proliferation, migration, and invasion capabilities of CRC cells were markedly attenuated, and the EMT process as well as Wnt/β-catenin signaling pathway activity were effectively suppressed. Notably, RFC4 silencing significantly reduced liver metastasis of CRC cells in a nude mouse model. However, the inhibitory effects of RFC4 silencing on CRC cells proliferation, migration, invasion, and EMT were partially reversed by the intervention of the Wnt/β-catenin signaling pathway activator BML-284. Altogether, these results indicate that RFC4 plays a critical role in promoting CRC metastasis, and its mechanism of action may involve the regulation of Wnt/β-catenin signaling pathway activation to facilitate EMT.
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MOLECULAR & CELLULAR PROTEOMICS
·
2026
·
IF 6.3
Hongyu Zhang,Baojin Zhou,Jingwen Liu,Yan Ren
Background and aim Platycodin D (PD), a major bioactive saponin isolated from the traditional Chinese medicine (TCM) Platycodon grandiflorus , has shown promising therapeutic potential against non-small cell lung cancer (NSCLC). However, the functional mechanisms of PD in NSCLC progression remains unclear. This study aimed to explore the pharmacological mechanism of PD against NSCLC. Materials and methods Thermal proteome profiling (TPP) approach, molecular docking, cellular thermal shift assay (CETSA) and peptide-centric local stability assay (PELSA) were employed to identify the potential binding target of PD. Subsequent Western Blot and immunoprecipitation-Western Blot (IP-WB) experiments were conducted to investigate the downstream signaling pathways of the target. Furthermore, proteomic and ubiquitinomic profiling of PD-treated cells were performed to investigate its functions on global. Results Replication factor C subunit 4 (RFC4) was identified as a potential binding target of PD by TPP and their binding sites were further exposed by PELSA. PD-RFC4 complex promotes the degradation of Notch1 and Notch3 by reducing nuclear entry of their domains. Compared with control treatment, the differentially expressed proteins induced by PD were found to be primarily involved in ferroptosis, ubiquitination, platinum drug resistance and ribosome-related processes. The ubiquitin proteome analysis revealed that proteins associated with the Notch pathway underwent ubiquitin modifications. Conclusions PD binds to RFC4 and inhibits its activity, leading to downregulation of the Notch signaling pathway, ultimately triggering cancer cell apoptosis. PD is a natural product with potential therapeutic value for NSCLC.
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高影响因子
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