Decreased IL-6 induces sensitivity of hepatocellular carcinoma cells to sorafenib

Anti-hepatocellular carcinoma activities of novel hydrazone derivatives via downregulation of interleukin-6

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related morbidity worldwide. Sorafenib is a first-line drug for the treatment of HCC, however, it is reported to cause serious adverse effects and may lead to resistance in many patients. In this study, 20 hydrazone derivatives incorporating triazoles, pyrazolone, pyrrole, pyrrolidine, imidazoline, quinazoline, and oxadiazine moieties were designed, synthesized, and characterized. In addition to molecular docking and in silico ADME study, the cytotoxic activity of the synthesized compounds was evaluated against the human hepatocellular cancer cell line (HepG2) and liver mesenchymal stem cells as a normal cell line. The antitumor activities of the derivatives against sorafenib were compared. Of the 20 synthesized compounds, compound 16 demonstrated potential as a potent anti-HCC drug candidate through downregulation of interleukin 6 which reduces inflammation and tumorigenesis with a strong binding interaction and bioavailability.

IL-6/STAT3 signaling pathway induces prostate apoptosis response protein-4(PAR-4) to stimulate malignant behaviors of hepatocellular carcinoma cells

INTRODUCTION AND OBJECTIVES

Prostate apoptosis response protein-4 (PAR-4) is considered a tumor suppressor. However, the role of PAR-4 in hepatocellular carcinoma (HCC) has rarely been reported. The study explores the role of PAR-4 in the malignant behaviors of HCC cells.

MATERIALS AND METHODS

TCGA database was applied to analyze the expression of PAR-4 in HCC. Evaluated PAR-4 relationship with clinical parameters and prognosis by tissue microarray; expression of STAT3, p-STAT3, Src and Ras was detected by Western blotting or laser confocal microscopy. Cell scratch and flow cytometry assays were used to observe IL-6 regulation of the malignant behaviors of HCC cells. The tumorigenic potential of HCC cells in vivo was evaluated in a nude mouse tumor model.

RESULTS

Analysis indicated that the expression of PAR-4 in HCC tissues was significantly higher than that in normal liver tissues; and PAR-4 interacted with STAT3. KEGG analysis showed that PAR-4 plays a role in the Janus kinase (JAK)/STAT signaling pathway. The positive expression rate of PAR-4 in HCC tissues was significantly higher than that in adjacent tissues. Positive correlation between IL-6 and PAR-4 expression in the HCC tissues. Exogenous IL-6 significantly promoted the proliferation and migration of HCC cells and up-regulated the expression of PAR-4 and p-STAT3 in HCC cells. Interference of the expression of PAR-4 could reduce the malignant behaviors of HCC cells and inhibit tumorigenesis in a nude mouse tumor model.

CONCLUSIONS

PAR-4 expression is positively correlated with HCC; PAR-4 promotes malignant behavior of HCC cells mediated by the IL-6/STAT3 signaling pathway.

Hepatocellular Carcinoma: Old and Emerging Therapeutic Targets

Liver cancer, predominantly hepatocellular carcinoma (HCC), globally ranks sixth in incidence and third in cancer-related deaths. HCC risk factors include non-viral hepatitis, alcohol abuse, environmental exposures, and genetic factors. No specific genetic alterations are unequivocally linked to HCC tumorigenesis. Current standard therapies include surgical options, systemic chemotherapy, and kinase inhibitors, like sorafenib and regorafenib. Immunotherapy, targeting immune checkpoints, represents a promising avenue. FDA-approved checkpoint inhibitors, such as atezolizumab and pembrolizumab, show efficacy, and combination therapies enhance clinical responses. Despite this, the treatment of hepatocellular carcinoma (HCC) remains a challenge, as the complex tumor ecosystem and the immunosuppressive microenvironment associated with it hamper the efficacy of the available therapeutic approaches. This review explores current and advanced approaches to treat HCC, considering both known and new potential targets, especially derived from proteomic analysis, which is today considered as the most promising approach. Exploring novel strategies, this review discusses antibody drug conjugates (ADCs), chimeric antigen receptor T-cell therapy (CAR-T), and engineered antibodies. It then reports a systematic analysis of the main ligand/receptor pairs and molecular pathways reported to be overexpressed in tumor cells, highlighting their potential and limitations. Finally, it discusses TGFβ, one of the most promising targets of the HCC microenvironment.

Norcantharidin potentiates sorafenib antitumor activity in hepatocellular carcinoma rat model through inhibiting IL-6/STAT3 pathway

In hepatocellular carcinoma (HCC), sorafenib (Sora) efficacy is limited by primary and/or acquired resistance. Emerging evidence shows that the inflammatory factor interleukin 6 (IL-6) plays a role in Sora resistance. Norcantharidin (NCTD), a derivative of cantharidine, was identified as a potent IL-6 inhibitor. Thus, in this study, we evaluated NCTD ability to improve the Sora efficacy in HCC and its underlying molecular mechanisms. Male Sprague Dawely rats were administered NCTD (0.1 mg/kg/day; orally) or Sora (10 mg/kg day; orally) or combination for 6 weeks after HCC induction using thioacetamide (200 mg/kg; ip; 2 times/wk) for 16 weeks. Our results showed that NCTD greatly enhanced Sora activity against HCC and potentiated Sora-induced oxidative stress. NCTD enhanced Sora-induced tumor immunity reactivation by decreasing both fibrinogen-like protein 1 level and increasing both tumor necrosis factor-α gene expression along with CD8+ T cells number. Also, NCTD augmented Sora attenuation activity against TAA-induced angiogenesis and metastasis by decreasing VEGFA, HIF-1α, serum lactate dehydrogenase enzyme, and vimentin levels. The combined use of NCTD/Sora suppressed drug resistance and stemness by downregulating ATP-binding cassette subfamily G member 2, neurogenic locus notch homolog protein, spalt-like transcription factor 4, and CD133. NCTD boosted Sora antiproliferative and apoptotic activities by decreasing Ccnd1 and BCL2 expressions along with increasing BAX and caspase-3 expressions. To our knowledge, this study represents the first study providing evidence for the potential novel therapeutic use of NCTD/Sora combination for HCC. Moreover, no previous studies have reported the effect of NCTD on FGL1.

Immunotherapy of hepatocellular carcinoma: recent progress and new strategy

Due to its widespread occurrence and high mortality rate, hepatocellular carcinoma (HCC) is an abhorrent kind of cancer. Immunotherapy is a hot spot in the field of cancer treatment, represented by immune checkpoint inhibitors (ICIs), which aim to improve the immune system's ability to recognize, target and eliminate cancer cells. The composition of the HCC immune microenvironment is the result of the interaction of immunosuppressive cells, immune effector cells, cytokine environment, and tumor cell intrinsic signaling pathway, and immunotherapy with strong anti-tumor immunity has received more and more research attention due to the limited responsiveness of HCC to ICI monotherapy. There is evidence of an organic combination of radiotherapy, chemotherapy, anti-angiogenic agents and ICI catering to the unmet medical needs of HCC. Moreover, immunotherapies such as adoptive cellular therapy (ACT), cancer vaccines and cytokines also show encouraging efficacy. It can significantly improve the ability of the immune system to eradicate tumor cells. This article reviews the role of immunotherapy in HCC, hoping to improve the effect of immunotherapy and develop personalized treatment regimens.

S-palmitoylation of PCSK9 induces sorafenib resistance in liver cancer by activating the PI3K/AKT pathway

Sorafenib is currently the first-line treatment for advanced hepatocellular carcinoma (HCC). However, sorafenib resistance remains a significant challenge. Aberrant AKT signaling activation is a crucial mechanism driving sorafenib resistance in HCC. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a vital role in antitumor immune responses. In this study, we demonstrate that aberrant PCSK9 upregulation promotes cell proliferation and sorafenib resistance in HCC by inducing AKT-S473 phosphorylation. After palmitoylation at cysteine 600, the binding affinity between PCSK9 and tensin homolog (PTEN) is dramatically increased, inducing lysosome-mediated PTEN degradation and subsequent AKT activation. We identify zinc finger DHHC-type palmitoyltransferase 16 (ZDHHC16) as a palmitoyltransferase that promotes PCSK9 palmitoylation at cysteine 600. We also develop a biologically active PCSK9-derived peptide that competitively inhibits PCSK9 palmitoylation, suppressing AKT phosphorylation and augmenting the antitumor effects of sorafenib in HCC.

Induction of IL-6Rα by ATF3 enhances IL-6 mediated sorafenib and regorafenib resistance in hepatocellular carcinoma

Sorafenib and its derivative regorafenib are the first- and second-line targeted drugs for advanced HCC, respectively. Although both drugs improve overall survival, drug resistance remains the major barrier to their full efficacy. Thus, strategies to enhance sorafenib and regorafenib efficacy against HCC are solely needed. Interleukin-6 receptor alpha (IL-6Rα) is the receptor of IL-6, a multi-functional cytokine, which plays key roles in liver-regeneration, inflammation and development of hepatocellular carcinoma (HCC). Here we show the expression of IL-6Rα was induced in response to sorafenib. Depletion of IL-6Rα abolished IL-6 induced STAT3 phosphorylation at 705th tyrosine and tumor growth of HCC cells under sorafenib treatment. Mechanistically, activating transcription factor 3 (ATF3) was induced in response to sorafenib and subsequently bound to the promoter of IL-6Rα, leading to its transcriptional activation. Depletion of ATF3 or its upstream transcription factor, ATF4, attenuated IL-6Rα induction and IL-6 mediated sorafenib resistance. The ATF4-ATF3-IL-6Rα cascade is also activated by regorafenib. Furthermore, blockade of IL-6Rα with the FDA approved IL-6Rα antibody drug, Sarilumab, drastically attenuated both sorafenib and regorafenib resistance in patient-derived xenograft (PDX) tumors, where human IL-6 could be detected by a novel in situ hybridization technique, named RNAscope. Together, our data reveal that ATF3-mediated IL-6Rα up-regulation promotes both sorafenib and regorafenib resistance in HCC, and targeting IL-6Rα represents a novel therapeutic strategy to enhance sorafenib/regorafenib efficacy for advanced HCC treatment.

IL-6/STAT3 Is a Promising Therapeutic Target for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumor of which the occurrence and development, the tumorigenicity of HCC is involving in multistep and multifactor interactions. Interleukin-6 (IL-6), a multifunctional inflammatory cytokine, has increased expression in HCC patients and is closely related to the occurrence of HCC and prognosis. IL-6 plays a role by binding to the IL-6 receptor (IL-6R) and then triggering the Janus kinase (JAK) associated with the receptor, stimulating phosphorylation and activating signal transducer and activator of transcription 3 (STAT3) to initiate downstream signals, participating in the processes of anti-apoptosis, angiogenesis, proliferation, invasion, metastasis, and drug resistance of cancer cells. IL-6/STAT3 signal axes elicit an immunosuppressive in tumor microenvironment, it is important to therapy HCC by blocking the IL-6/STAT3 signaling pathway. Recent, some inhibitors of IL-6/STAT3 have been development, such as S31-201 or IL-6 neutralizing monoclonal antibody (IL-6 mAb), Madindoline A (Inhibits the dimerization of IL-6/IL-6R/gpl30 trimeric complexes), C188-9 and Curcumin (Inhibits STAT3 phosphorylation), etc. for treatment of cancers. Overall, consideration of the IL-6/STAT3 signaling pathway, and its role in the carcinogenesis and progression of HCC will contribute to the development of potential drugs for targeting treatment of liver cancer.

Nicotinic acetylcholine receptors in chemotherapeutic drugs resistance: An emerging targeting candidate

There is no definitive cure for cancer, and most of the current chemotherapy drugs have limited effects due to the development of drug resistance and toxicity at high doses. Therefore, there is an ongoing need for identifying the causes of chemotherapeutic resistance, and it will be possible to develop innovative treatment approaches based on these novel targeting candidates. Cigarette smoking is known to be one of the main causes of resistance to chemotherapeutic agents. Nicotine as a component of cigarette smoke is an exogenous activator of nicotinic acetylcholine receptors (nAChRs). It can inhibit apoptosis, increase cell proliferation and cell survival, reducing the cytotoxic effects of chemotherapy drugs and cause a reduced therapeutic response. Recent studies have demonstrated that nAChRs and their downstream signaling pathways have considerable implications in different cancer's initiation, progression, and chemoresistance. In some previous studies, nAChRs have been targeted to obtain better efficacies for chemotherapeutics. Besides, nAChRs-based therapies have been used in combination with chemotherapy drugs to reduce the side effects. This strategy requires lower doses of chemotherapy drugs compared to the conditions that must be used alone. Here, we discussed the experimental and clinical studies that show the nAChRs involvement in response to chemotherapy agents. Also, controversies relating to the effects of nAChR on chemotherapy-induced apoptosis are in our focus in this review article. Delineating the complex influences of nAChRs would be of great interest in establishing new effective chemotherapy regimens.