The Role of Ferroptosis in the Treatment and Drug Resistance of Hepatocellular Carcinoma

Ferroptosis: a new promising target for hepatocellular carcinoma therapy

Hepatocellular carcinoma (HCC) is the sixed most common malignant tumor in the world. The study for HCC is mired in the predicament confronted with the difficulty of early diagnosis and high drug resistance, the survival rate of patients with HCC being low. Ferroptosis, an iron-dependent cell death, has been discovered in recent years as a cell death means with tremendous potential to fight against cancer. The in-depth researches for iron metabolism, lipid peroxidation and dysregulation of antioxidant defense have brought about tangible progress in the firmament of ferroptosis with more and more results showing close connections between ferroptosis and HCC. The potential role of ferroptosis has been widely used in chemotherapy, immunotherapy, radiotherapy, and nanotherapy, with the development of various new drugs significantly improving the prognosis of patients. Based on the characteristics and mechanisms of ferroptosis, this article further focuses on the main signaling pathways and promising treatments of HCC, envisioning that existing problems in regard with ferroptosis and HCC could be grappled with in the foreseeable future.

LINC01370 suppresses hepatocellular carcinoma proliferation and metastasis by regulating the PI3K/AKT pathway

BACKGROUND

Hepatocellular carcinoma (HCC) poses a serious threat to human health worldwide. lncRNA dysregulation is frequently observed in various cancers, including HCC. However, the function of LINC01370 in HCC progression and its underlying mechanisms remain unclear.

METHODS

LINC01370 expression in HCC tissues with cells was analyzed by applying the GEO and GEPIA databases and qRT-PCR. CCK-8 and Transwell assays were used to assess HCC cell proliferation, migration, and invasion. The PI3K, AKT, with p-AKT protein expression were analyzed by western blotting.

RESULTS

Gene Expression Omnibus (GEO) and Gene Expression Profiling Interactive Analysis (GEPIA) showed that LINC01370 expression was significantly lower in HCC tissues than in normal tissues. LINC01370 overexpression markedly repressed HepG2 SMMC-7721 cells proliferation, migration, and invasion. To understand the downstream mechanism of LINC01370 regulation, we further analyzed the genes co-expressed with LINC01370 in GSE136247 and GSE132037 and then performed KEGG analysis. The PA pathway was found to be a downstream pathway regulated by LINC01370 in GSE136247 and GSE132037 via gene co-expression and KEGG analysis. Furthermore, PI3K and p-AKT protein levels decreased after LINC01370 overexpression. Importantly, rescue experiments showed that activation of the PI3K/AKT pathway disrupted the repressive effect of LINC01370 overexpression on the proliferation, migration, and invasion of HepG2 of SMMC-7721 cells.

CONCLUSIONS

This study verified that LINC01370 suppresses HCC proliferation with metastasis by regulating the PI3K/AKT pathway.

SLC7A11 in hepatocellular carcinoma: potential mechanisms, regulation, and clinical significance

Exploring novel early detection biomarkers and developing more efficacious treatments remain pressing tasks in the current research landscape for hepatocellular carcinoma (HCC). Morphologically and molecularly separate from apoptosis, cell death, and autophagy, ferroptosis is a recently discovered, unique, controlled form of cell death. SLC7A11 (also known as xCT) represents a subunit of the cystine-glutamate antiporter (also known as system Xc(-)). A growing body of research suggests that induction of ferroptosis through SLC7A11 can effectively eliminate hepatocellular carcinoma (HCC) cells, particularly those exhibiting resistance to alternative forms of cell death. Thus, targeting ferroptosis via SLC7A11 may become a new direction for the design of therapeutic strategies for HCC. Although many research articles have investigated the possible roles of SLC7A11 in HCC, a study that summarizes the main findings, including the regulators and mechanisms of action of SLC7A11 in HCC is not available. Therefore, we present a comprehensive overview of the functions of ferroptosis, particularly SLC7A11, in the identification, development, and management of HCC in this review. In addition, we discuss how this knowledge can be translated into treatment by providing a systemic therapy in advanced HCC using sorafenib, the first-line drug targeting multiple kinases and SLC7A11. We further dissect the possible barriers as well as the corresponding solutions and provide insights on how to navigate effective treatment using this knowledge.

Inhibition of Apoc1 reverses resistance of sorafenib by promoting ferroptosis in esophageal cancers

Drug resistance is an obstacle in therapy of esophageal cancers (ECs), and the role of ferroptosis in progression ECs is still not clearly clarified. In the present study, we investigated the role of Apolipoprotein C1 (Apoc1) in regulating the sorafenib resistance in EC cells. Apoc1 was knock down after infection with Apoc1 shRNA lentivirus and stable cell lines for Apoc1 knockdown were screened. Cell viabilities were tested by MTT assay. ROS, MDA, and GSH tested by specific kits. In vivo experiment in nude mice were performed to test the correlation of Apoc1 and ferroptosis. The expression of Apoc1 and GPX4 was tested by western blotting. The results showed that Apoc1 was highly expressed in EC tissues and associated with poor overall survival rate of EC. Knockdown Apoc1 overcame resistance of sorafenib in EC cells and promoted erastin and sorafenib induced ferroptosis by upregulating the levels of ROS and MDA and downregulating the level of GSH in OE19/Sora and EC109/Sora cells. Rescue experiments proved that Apoc1 regulated sorafenib induced ferroptosis via GPX4. Furthermore, knockdown of Apoc1 inhibited the tumor progression by promoting ferroptosis in nude mice. In conclusion, knockdown Apoc1 overcome resistance of sorafenib in EC cells and in vivo by promoting sorafenib induced ferroptosis via GPX4. Targeting Apoc1 might be an effective way to reverse the drug resistance of sorafenib via inducing ferroptosis in EC progression.

Inhibition of NRF2 enhances the acute myeloid leukemia cell death induced by venetoclax via the ferroptosis pathway

Venetoclax, an inhibitor that selectively targets B cell lymphoma-2 (BCL-2) that has been approved for treating adult acute myeloid leukemia (AML) in combination with hypomethylating agents. However, its short duration of response and emergence of resistance are significant issues. In this study, we found that the sensitivity of AML cells to venetoclax was considerably enhanced by ML385, an inhibitor of the ferroptosis factor nuclear transcription factor erythroid 2-related factor 2 (NRF2). Using AML samples, we verified that NRF2 and its target gene ferritin heavy chain 1 (FTH1) were highly expressed in patients with AML and correlated with poor prognosis. Downregulation of NRF2 could inhibit FTH1 expression and significantly enhance the venetoclax-induced labile iron pool and lipid peroxidation. By contrast, NRF2 overexpression or administration of the reactive oxygen species inhibitor N-acetylcysteine and vitamin E could effectively suppress the anti-AML effects of ML385+venetoclax. Furthermore, the ferroptosis inducer erastin increased the anti-AML effects of venetoclax. Our study demonstrated that NRF2 inhibition could enhance the AML cell death induced by venetoclax via the ferroptosis pathway. Thus, the combination of ML385 with venetoclax may offer a favorable strategy for AML treatment.

Targeted ferroptotic potency of ferrous oxide nanoparticles-diethyldithiocarbamate nanocomplex on the metastatic liver cancer

Existing treatments are frequently ineffective in combating liver cancer (LC) due to its rapid growth, high metastatic potential, and chemoresistance. Thus, inducing ferroptosis, a new non-apoptotic regulated cell death-dependent massive iron overload-mediated lipid peroxidation, is an alternative effective approach for treating LC. The efficient trigger of ferroptosis requires blocking cellular antioxidant (anti-ferroptosis) response and selectivity to avoid harming other healthy tissues. In this study, green chemically synthesized ferrous oxide nanoparticles (F(II) NPs) were used for enhancing selective iron accumulation in tumor tissue, while diethyldithiocarbamate (DE) was for inhibiting the antioxidant system (glutathione and aldehyde dehydrogenase (ALDH) 2) which protects the tumor from damage-dependent lipid peroxides. Thus, F(II) NPs were used with DE as nanocomplex (DF(II) NPs) and its anti-LC activity compared to ferrous oxide DF(II). DF(II) NPs outperformed the typical complex of DF(II) in eradicating metastatic LC cells in HepG2 cells and a chemically induced metastatic LC animal model, as evidenced by flow cytometry, histological and immunohistochemical analyses, and α-fetoprotein depletion. The superior therapeutic potency-dependent ferroptotic activity of DF(II) NPs, attributed to their higher selective accumulation (∼77%) than DF(II) in tumor tissues (liver and lung), resulted in a strong elevation of cellular lipid peroxidation with extreme suppression of nuclear related factor 2 (Nrf2) transcriptional activity, glutathione (GSH), glutathione peroxidase 4, and ALDH2. Subsequently, a severe inhibition in the expression of oncogenes and metastatic cancer stem cell genes was recorded in DF(II) NPs-treated LC animal group. In contrast to DF(II), DF(II) NPs were able to normalize liver functions and did not show any variations in hematological and histological parameters in the blood and tissues of DF(II) NPs-treated normal mouse group. These findings validate the potency and safety of DF(II) nanocomplex as a promising nanodrug for combating metastatic LC.

Ferroptosis: A novel therapeutic strategy and mechanism of action in glioma

Glioma is the most common malignant tumor of the central nervous system and resistance is easily developed to chemotherapy drugs during the treatment process, resulting in high mortality and short survival in glioma patients. Novel therapeutic approaches are urgently needed to improve the therapeutic efficacy of chemotherapeutic drugs and to improve the prognosis of patients with glioma. Ferroptosis is a novel regulatory cell death mechanism that plays a key role in cancer, neurodegenerative diseases, and other diseases. Studies have found that ferroptosis-related regulators are closely related to the survival of patients with glioma, and induction of ferroptosis can improve glioma resistance to chemotherapy drugs. Therefore, induction of tumor cell ferroptosis may be an effective therapeutic strategy for glioma. This review summarizes the relevant mechanisms of ferroptosis, systematically summarizes the key role of ferroptosis in the treatment of glioma and outlines the relationship between ferroptosis-related ncRNAs and the progression of glioma.

Gentian violet induces apoptosis and ferroptosis via modulating p53 and MDM2 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common malignancies with limited curative options and poor prognosis. Gentian violet (GV) has recently been found to have anti-tumor properties with promising clinical applications. However, its anti-tumor effect and the underlying functional mechanisms in HCC have not been investigated. In this study, we found that GV induced ferroptosis and apoptosis, inhibited cell proliferation, migration and invasion in a dose-dependent manner in vitro, and significantly attenuated the growth of HCC in vivo. Both ferroptosis inhibitor Ferrostain-1 (Fer-1) and apoptosis inhibitor Z-VAD-KFM (Z-VAD) partially attenuated GV-induced growth-inhibitory effects, while combined treatment of Fer-1 and Z-VAD completely abolished GV's activities. Increased levels of intracellular reactive oxygen species (ROS) were detected after GV treatment. Interestingly, GV elevated the expression levels of both p53 and its negative regulator MDM2, which was dependent on the expression of the dehydrogenase/reductase protein Hep27. Simultaneously silencing both the MDM2 and p53 genes by siRNAs abolished ROS production and partially rescued the cell death induced by GV treatment. Our data demonstrate a GV-Hep27-MDM2-p53 signaling cascade that regulates ferroptosis and apoptosis. Furthermore, our findings provide insights into understanding the anti-tumor function of GV and present the basis of new therapeutic strategies for the treatment of HCC.