cblc137 and Liver-Neoplasms

Facilitates Chromatin Transcription (FACT) complex is a histone chaperone participating in DNA repair-related and transcription-related chromatin dynamics. In this study, we investigated its oncogenic functions, underlying mechanisms and therapeutic implications in human hepatocellular carcinoma (HCC).. We obtained HCC and its corresponding non-tumorous liver samples from 16 patients and identified FACT complex as the most upregulated histone chaperone by RNA-Seq. We further used CRISPR-based gene activation and knockout systems to demonstrate the functions of FACT complex in HCC growth and metastasis. Functional roles and mechanistic insights of FACT complex in oxidative stress response were investigated by ChIP assay, flow cytometry, gene expression assays and 4sU-DRB transcription elongation assay. Therapeutic effect of FACT complex inhibitor, Curaxin, was tested in both in vitro and in vivo models.. We showed that FACT complex was remarkably upregulated in HCC and contributed to HCC progression. Importantly, we unprecedentedly revealed an indispensable role of FACT complex in NRF2-driven oxidative stress response. Oxidative stress prevented NRF2 and FACT complex from KEAP1-mediated protein ubiquitination and degradation. Stabilised NRF2 and FACT complex form a positive feedback loop; NRF2 transcriptionally activates the FACT complex, while FACT complex promotes the transcription elongation of NRF2 and its downstream antioxidant genes through facilitating rapid nucleosome disassembly for the passage of RNA polymerase. Therapeutically, Curaxin effectively suppressed HCC growth and sensitised HCC cell to sorafenib.. In conclusion, our findings demonstrated that FACT complex is essential for the expeditious HCC oxidative stress response and is a potential therapeutic target for HCC treatment.

Topics: Animals; Antineoplastic Agents; Carbazoles; Carcinoma, Hepatocellular; Cell Cycle Proteins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Disease Progression; DNA-Binding Proteins; Gene Expression Regulation, Neoplastic; Gene Knockout Techniques; High Mobility Group Proteins; Histone Chaperones; Humans; Liver Neoplasms; Liver Neoplasms, Experimental; Mice, Inbred BALB C; Mice, Nude; Oxidative Stress; Sorafenib; Transcription Factors; Transcriptional Elongation Factors; Up-Regulation; Xenograft Model Antitumor Assays

Hepatocellular carcinoma (HCC) is one of the deadliest cancers worldwide due to the lack of effective therapy methods. Therefore, there is an urgent need to develop novel therapies for HCC. CBL0137 is a small molecule that affects p53 and nuclear factor-kappa B (NF-κB). The expression of p53 was measured by using immunohistochemistry (IHC) in tumor and adjacent tissues. Western blotting (WB) and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to detect the level of p-p53, p53, Bax, and PUMA after CBL0137 administration. CCK-8 and immunofluorescence staining (IF) assays were performed to evaluate the proliferation and viability of HCC cells. Flow cytometry was used to detect the apoptosis of HCC cells. Xenograft model was established to determine the effect of CBL0137 treatment on HCC tumor growth in vivo. HE staining was used to monitor HCC cell morphology and IHC staining for Ki-67 was performed to determine the tumor cell proliferation following CBL0137 treatment. Results showed that the expression of p-p53, p53, Bax, and PUMA was upregulated after CBL0137 administration. The viability, growth, and colony formation of HCC cells were significantly inhibited by CBL0137 in the CBL group compared with the NC group (p<0.05). Meanwhile, the results revealed that the proportions of apoptotic and necrotic cells were significantly elevated in the CBL group compared to the NC group (p<0.05). And the apoptosis-related proteins including PARP, caspase-3, caspase-7, caspase-8, and caspase-9 were increased in the CBL group compared with the NC group (p<0.05), while the NF-κB, p-NF-κB and p-AKT expression levels were significantly downregulated following CBL0137 treatment (p<0.05). Additionally, the tumor volume and weight were significantly reduced in the CBL group compared with the NC group (p<0.05). Moreover, HE staining and IHC staining for Ki-67 indicated that CBL0137 treatment could obviously induce cell apoptosis and suppress cell proliferation. CBL0137 treatment could effectively inhibit HCC cell proliferation and induce cell apoptosis associated with multiple factors expression.

Topics: Apoptosis; Apoptosis Regulatory Proteins; bcl-2-Associated X Protein; Carbazoles; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Humans; Liver Neoplasms; Proto-Oncogene Proteins; Tumor Suppressor Protein p53