Action In Hepatocellular Carcinoma Research Articles

ONC206 targeting ClpP induces mitochondrial dysfunction and protective autophagy in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most common form of liver cancer, accounting for approximately 90 % of all cases. ONC201, a member of the imipridone drug family, has shown promising therapeutic potential and a good safety profile in both malignant pediatric central nervous system tumors (diffuse midline glioma [DMG]) and hematologic malignancies. ONC206 is a more potent analog of ONC201. However, the ONC206 potential and mechanism of action in HCC remain to be elucidated. We found that ONC206 hindered HCC growth by suppressing cell proliferation and inducing apoptosis. Moreover, ONC206 induced cytoprotective autophagy, and blocking autophagy enhanced the proapoptotic effect of ONC206. Additionally, ONC206 induced mitochondrial swelling, reduced the mitochondrial membrane potential (MMP), and led to the accumulation of mitochondrial ROS in HCC cells, ultimately resulting in mitochondrial dysfunction. The HCC patient samples exhibited notably elevated levels of caseinolytic protease proteolytic subunit (ClpP), which serves as a mediator of ONC206-induced mitochondrial dysfunction and the activation of protective autophagy. knockdown of ClpP reversed the cytotoxic effects of ONC206 on HCC cells. In summary, our results provide the first insight into the mechanism by which ONC206 exerts its anti-HCC effects and induces protective autophagy in HCC cells through ClpP.

Therapeutic targets for metabolic dysfunction-associated steatotic liver disease and their roles in hepatocellular carcinoma

Metabolic dysfunction-associated steatotic liver disease (MASLD) is one of the most common chronic liver diseases. Over time, there has been a significant increase in the prevalence of MASLD. It has become one of the leading causes of hepatocellular carcinoma (HCC) in the United States, France, and the United Kingdom. Globally, the incidence of HCC related to MASLD may further increase with the growing prevalence of obesity. Non-alcoholic steatohepatitis (NASH) is an important stage of MASLD, which is more likely to cause cirrhosis and even HCC. And patients with NASH cirrhosis have a much higher incidence of hepatocellular cancer than patients with non-cirrhotic MASLD. As a result, it is critical to investigate the targets of MASLD therapy in HCC. This article reviews therapeutic targets of MASLD, such as farnesoid X receptor (FXR), peroxisome proliferator activated receptor (PPAR), fibroblast growth factor-21 (FGF-21), etc., and introduces the drugs related to these targets and their mechanisms of action in HCC. In addition, the developmental process and pathogenesis of MASLD, as well as risk factors for HCC development, are discussed. These are of great significance for the prevention and treatment of HCC.

Hsa-circ-0000098 promotes the progression of hepatocellular carcinoma by regulation of miR-136-5p/MMP2 axis.

Many papers revealed the abnormal expression of circular RNA (circRNA), a kind of non-coding RNA, in mammals. However, the potential functional mechanisms are still unknown. In this paper, we aimed to elucidate the function and mechanisms of hsa-circ-0000098 in hepatocellular carcinoma (HCC). Bioinformatics was used to analyze the Gene Expression Omnibus (GEO) database (GSE97332) and predict the targeted gene site of miR-136-5p. The starBase online database was utilized to predict that MMP2 is the downstream target gene of miR-136-5p. The expression of hsa_circ_0000098, miR-136-5p and matrix metalloproteinase 2 (MMP2) in HCC tissues or cells was detected using quantitative real-time polymerase chain reaction (qRT-PCR) method. The migration and invasion abilities of processing cells were measured with transwell assay. The luciferase reporter assay was carried out to verify the targets of hsa_circ_0000098, MMP2 and miR-136-5p. The western blot assay was performed to detect the expression of MMP2, MMP9, E-cadherin, and N-cadherin. According to the analysis of GEO database of GSE97332, hsa_circ_0000098 had a prominent expression in HCC tissues. A continued analysis of relevant patients has verified that the high expression of hsa_circ_0000098 is present in HCC tissues with relative to poor prognosis. We also proved that the migration and invasion abilities of HCC cell lines can be inhibited by silencing hsa_circ_0000098. In view of the above findings, we continued to study the hsa_circ_0000098 mechanism of action in HCC. The study revealed that hsa_circ_0000098 can sponge miR-136-5p and then regulate MMP2, which is a downstream target gene of miR-136-5p, in order to promote HCC metastasis by regulation of miR-136-5p/MMP2 axis. Our data showed that has_circ_0000098 facilitates the migration, invasion and malignant progression of HCC. On the other hand, we demonstrated that the mechanism of action of hsa_circ_0000098 in HCC might be due to the regulation of miR-136-5p/MMP2 axis.

Virtual screening identifies tipranavir as a SIRT1 inhibitor with anti-hepatocarcinoma effect.

Aim: To identify novel inhibitors of SIRT1 and to understand their mechanism of action in hepatocellular carcinoma. Materials & methods: Molecular docking and dynamic simulations were conducted to identify potential SIRT1 inhibitors. The in vitro efficacy of the inhibitors was evaluated by methyl thiazolyl tetrazolium assays, flow cytometry and western blot analysis. Additionally, the in vivo antitumor activity of the inhibitor was evaluated. Results: Tipranavir, a US FDA-approved anti-HIV-1 medication, was found to possess potential as a SIRT1 inhibitor. Tipranavir selectively inhibited HepG2 cell proliferation without causing toxicity to normal human hepatic cells. Additionally, tipranavir treatment resulted in a reduction of SIRT1 expression and induction of apoptosis in HepG2 cells. Furthermore, tipranavir was found to suppress tumorigenesis in a xenograft mouse model and decreased the expression of SIRT1 in vivo. Conclusion: Tipranavir holds desirable potential as a promising therapeutic agent against hepatoma.

GNB1 promotes hepatocellular carcinoma progression by targeting BAG2 to activate P38/MAPK signaling.

G-proteins are intracellular partners of G-protein-coupled receptors. As a member of the G-protein family, GNB1 has been shown to play a pro-cancer role in lung cancer and breast cancer. However, the biological function and detailed mechanisms of GNB1 in hepatocellular carcinoma progression are unclear. In this study, we investigated the effects of GNB1 and its possible mechanism of action in hepatocellular carcinoma (HCC). The clinical significance of GNB1 was evaluated in a large cohort of HCC patients, showing that GNB1 was overexpressed in HCC compared to adjacent normal liver tissues, and increased GNB1 expression was associated with poor prognosis. We also demonstrated that GNB1 enhances cell proliferation, colony formation, and cell migration and invasion in vitro and promotes the epithelial-to-mesenchymal transition process in HCC cells. Tumor xenograft model assay confirmed the oncogenic role of GNB1 in tumorigenicity in nude mice. Activation of P38 signaling was found in the GNB1 overexpressed HCC cells. Further intervention of P38 confirmed it as an important signaling pathway for the oncogenic role of GNB1 in HCC. Moreover, co-immunoprecipitation followed by liquid chromatograph-mass spectrometry identified that GNB1 exerted oncogenic functions via the interaction of BAG2 and activated P38 signaling pathway. Together, our results reveal that GNB1 plays a pivotal oncogenic role in HCC by promoting the P38 pathway via cooperating with BAG2. GNB1 may serve as a prognostic biomarker for patients with HCC.

Discovery of a Nur77-mediated cytoplasmic vacuolation and paraptosis inducer (4-PQBH) for the treatment of hepatocellular carcinoma

Nur77, an orphan nuclear receptor, has antitumor activity in hepatocellular carcinoma (HCC). However, its antitumor mechanisms of action in HCC are complicated and rarely reported. Our recent work demonstrated that certain quinoline-Schiff-base derivatives were good Nur77 mediators that exerted excellent anti-HCC activities in vitro and in vivo. Interestingly, these compounds shared similar chemical structures, but they displayed different Nur77-targeted anticancer mechanisms of action. As a continuous work, we synthesized a series of 4-(quinoline-4-amino) benzoylhydrazide derivatives and evaluated their anti-HCC activity and binding affinity to Nur77 in vitro. Compound 4-PQBH emerged as the best Nur77 binder (KD = 1.17 μM) and has potentially selective cytotoxicity to HCC cells. Mechanistically, 4-PQBH extensively induced caspase-independent cytoplasmic vacuolization and paraptosis through Nur77-mediated ER stress and autophagy. Moreover, 4-PQBH exhibited an effective xenograft tumor inhibition by modulating Nur77-dependent cytoplasmic vacuolation and paraptosis. This paper is the first to disclose that chemotherapeutic agents targeting Nur77-mediated cytoplasmic vacuolization and paraptosis may provide a promising strategy to combat HCC that frequently evade the apoptosis program.

M6A Modification-Mediated DUXAP8 Regulation of Malignant Phenotype and Chemotherapy Resistance of Hepatocellular Carcinoma Through miR-584-5p/MAPK1/ERK Pathway Axis.

Hepatocellular carcinoma (HCC) has a poor prognosis due to its high malignancy, rapid disease progression, and the presence of chemotherapy resistance. Long-stranded non-coding RNAs (lncRNAs) affect many malignant tumors, including HCC. However, their mechanism of action in HCC remains unclear. This study aimed to clarify the role of DUXAP8 in regulating the malignant phenotype and chemotherapy resistance in HCC. Using an in vivo xenograft tumor model, the regulatory functions and mechanisms of lncRNA DUXAP8 in the progression and response of HCC to chemotherapy were explored. It was found that DUXAP8 was significantly upregulated in a patient-derived xenograft tumor model based on sorafenib treatment, which is usually associated with a relatively poor prognosis in patients. In HCC, DUXAP8 maintained its upregulation in the expression by increasing the stability of m6A methylation-mediated RNA. DUXAP8 levels were positively correlated with the proliferation, migration, invasion, and chemotherapy resistance of HCC in vivo and in vitro. In the mechanistic study, it was found that DUXAP8 competitively binds to miR-584-5p through a competing endogenous RNA (ceRNA) mechanism, thus acting as a molecular sponge for miR-584-5p to regulate MAPK1 expression, which in turn activates the MAPK/ERK pathway. These findings can provide ideas for finding new prognostic indicators and therapeutic targets for patients with HCC.

Dietary Intake of 17α-Ethinylestradiol Promotes HCC Progression in Humanized Male Mice Expressing Sex Hormone-Binding Globulin.

Hepatocellular carcinoma (HCC) is a male-oriented malignancy; its progression is affected by sex hormones. 17α-ethinylestradiol (EE2) is a synthetic estrogen widely used as an oral contraceptive; however, it is unknown whether EE2 regulates sex hormone action in HCC. We investigated whether EE2 influences HCC risk in male androgenic environments, using mice expressing human sex hormone-binding globulin (SHBG). Two-week-old male mice were injected with diethyl-nitrosamine (DEN, 25 mg/kg) and fed an EE2 diet for 10 weeks from 30 weeks of age. Development and characteristics of liver cancer were evaluated in 40-week-old mice via molecular and histological analyses. Although EE2 did not increase HCC progression in wild-type mice, SHBG mice exhibited remarkably higher HCC risk when fed EE2. The livers of EE2-treated SHBG mice exhibited substantially increased pro-inflammatory necrosis with high plasma levels of ALT and HMGB1, and intrahepatic injury and fibers. Additionally, increased androgen response and androgen-mediated proliferation in the livers of EE2-treated SHBG mice and EE2-exposed hepatocytes under SHBG conditions were observed. As a competitor of SHBG-androgen binding, EE2 could bind with SHBG and increase the bioavailability of androgen. Our results revealed that EE2 is a novel risk factor in androgen-dominant men, predisposing them to HCC risk.

MOF upregulates the estrogen receptor α signaling pathway by its acetylase activity in hepatocellular carcinoma.

The histone acetyltransferase MOF (KAT8) is mainly involved in the acetylation of histone H4 at lysine 16 (H4K16) and some non‐histone proteins. The MOF expression level is significantly reduced in many cancers, however the biological function of MOF and its underlying mechanism are still elusive in hepatocellular carcinoma (HCC). Estrogen receptor α (ERα) has been considered as a tumor suppressor in HCC. Here, we demonstrated that MOF expression is significantly reduced in HCC samples, and is positively correlated with that of ERα. MOF interacts with ERα, and participates in acetylation of ERα at K266, K268, K299, thereby inhibiting ERα ubiquitination to maintain the stability of ERα. In addition, MOF participates in the upregulation of ERα‐mediated transactivation. Depletion of MOF significantly promotes cell growth, migration, and invasion in HCC cell lines. Taken together, our results provide new insights to understand the mechanism underlying the modulation function of MOF on ERα action in HCC, suggesting that MOF might be a potential therapeutic target for HCC.

Therapeutic efficacy of a Dioscorea membranacea extract in a rat model of hepatocellular carcinoma: Histopathological aspects

Hepatocellular carcinoma (HCC) is most common in adults and has a high mortality rate because of a lack of effective treatment options. We investigated the effect of a medicinal plant as a potential source of drugs against HCC. The rhizomes of Dioscorea membranacea Pierre (DM), Hua-Khao-Yen in Thai, are commonly used as ingredients for alternative treatment of cancer in Thailand. In this study, the anticancer effects of DM extract in HCC-bearing rats were evaluated with respect to gross morphology, histopathology, and leakage of liver enzymes. In untreated HCCs, typical features of liver cancer, including hepatic nodules, thick-cell cords, and pseudoglandular cell arrangements, were observed. In addition, the HCCs showed abnormal reticulin patterns and a high glypican3 expression. In HCC-bearing rats treated with DM the cancer areas and reticulin expression were significantly reduced compared to the untreated group (p < 0.01). Sorafenib, the standard drug to treat HCC, reduced the cancer area further, but increased leakage of liver enzymes and decreased serum albumin concentration, indicating liver toxicity. These findings suggest that DM has an anticancer effect on HCCs in an animal model in vivo with potentially less severe side effects than sorafenib. Therefore, further studies of DM’s mechanism of action in HCC should be carried out.

BAP31 Promotes Tumor Cell Proliferation by Stabilizing SERPINE2 in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) patients are mostly diagnosed at an advanced stage, resulting in systemic therapy and poor prognosis. Therefore, the identification of a novel treatment target for HCC is important. B-cell receptor-associated protein 31 (BAP31) has been identified as a cancer/testis antigen; however, BAP31 function and mechanism of action in HCC remain unclear. In this study, BAP31 was demonstrated to be upregulated in HCC and correlated with the clinical stage. BAP31 overexpression promoted HCC cell proliferation and colony formation in vitro and tumor growth in vivo. RNA-sequence (RNA-seq) analysis demonstrated that serpin family E member 2 (SERPINE2) was downregulated in BAP31-knockdown HCC cells. Coimmunoprecipitation and immunofluorescence assays demonstrated that BAP31 directly binds to SERPINE2. The inhibition of SERPINE2 significantly decreased the BAP31-induced cell proliferation and colony formation of HCC cells and phosphorylation of Erk1/2 and p38. Moreover, multiplex immunohistochemistry staining of the HCC tissue microarray showed positive associations between the expression levels of BAP31, SERPINE2, its downstream gene LRP1, and a tumor proliferation marker, Ki-67. The administration of anti-BAP31 antibody significantly inhibited HCC cell xenograft tumor growth in vivo. Thus, these findings suggest that BAP31 promotes tumor cell proliferation by stabilizing SERPINE2 and can serve as a promising candidate therapeutic target for HCC.

Ziyuglycoside II exerts antiproliferative and antimetastasis effects on hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. Phytochemicals are important candidates for developing anticancer agents. Ziyuglycoside II is a major active compound of Sanguisorba officinalis, which exhibits antiproliferation activity in several cancers; however, its action in HCC remains unknown. In this study, we investigated the antitumor activity of ziyuglycoside II against HCC and explored the potential mechanisms. We found that ziyuglycoside II exerts significant inhibitory effects on the viability and clonogenic activity of HCC cells. The proliferation repression mediated by ziyuglycoside II was mainly due to increased apoptosis and reactive oxygen species accumulation, as well as a G0/G1 phase cell-cycle arrest. Additionally, ziyuglycoside II markedly impaired HCC cell migration and invasion, two important steps during metastasis, and these suppressive effects may be attributed to the downregulation of matrix metalloproteinases MMP2 and MMP9 expression. Moreover, ziyuglycoside II blocked the epidermal growth factor receptor/nuclear factor kappa-B (EGFR/NF-kB) signaling, which may contribute to its anticancer activity. Taken together, our findings reveal antiproliferative and antimetastasis activities of ziyuglycoside II in HCC cells, implying that ziyuglycoside II might be a promising candidate for the development of novel anti-HCC drugs.

Long Intergenic Nonprotein Coding RNA 0152 Promotes Hepatocellular Carcinoma Progression by Regulating Phosphatidylinositol 3-Kinase/Akt/Mammalian Target of Rapamycin Signaling Pathway through miR-139/PIK3CA

Hepatocellular carcinoma (HCC) ranks as the fifth most common cancer worldwide, and it is the primary histologic subtype of liver cancer, with high incidence and poor prognosis. Recently, numerous long noncoding RNAs have been reported to be associated with the tumorigenesis of HCC; however, the underlying mechanisms of long intergenic nonprotein coding RNA 0152 (LINC00152) action in HCC are poorly understood. Herein, we identified a significant up-regulation of LINC00152 in both HCC tissues and cell lines. Functional studies showed that knockdown of LINC00152 inhibited cell proliferation, migration, and invasion, but promoted cell apoptosis, indicating its oncogenic functions in HCC tumorigenesis. Mechanistically, LINC00152 functioned as an efficient miR-139 sponge, thereby releasing the suppression of PIK3CA (a target gene of miR-139). Anti-miR-139 rescued the inhibition of cell proliferation, migration, and invasion induced by LINC00152 knockdown. Similarly, PIK3CA-overexpressing plasmid also reversed miR-139-mediated biological functions in HCC cells. Taken together, our study revealed a crucial regulatory network of LINC00152/miR-139/PIK3CA axis in the tumorigenesis of HCC, implying that LINC00152 may be a biomarker and novel therapeutic target for further clinical therapy of HCC.

Multiscale systems pharmacological analysis of everolimus action in hepatocellular carcinoma.

Dysregulation of mTOR pathway is common in hepatocellular carcinoma (HCC). A translational quantitative systems pharmacology (QSP), pharmacokinetic (PK), and pharmacodynamic (PD) model dissecting the circuitry of this pathway was developed to predict HCC patients' response to everolimus, an mTOR inhibitor. The time course of key signaling proteins in the mTOR pathway, HCC cells viability, tumor volume (TV) and everolimus plasma and tumor concentrations in xenograft mice, clinical PK of everolimus and progression free survival (PFS) in placebo and everolimus-treated patients were extracted from literature. A comprehensive and multiscale QSP/PK/PD model was developed, qualified, and translated to clinical settings. Model fittings and simulations were performed using Monolix software. The S6-kinase protein was identified as critical in the mTOR signaling pathway for describing everolimus lack of efficacy in HCC patients. The net growth rate constant (kg) of HCC cells was estimated at 0.02h-1 (2.88%RSE). The partition coefficient of everolimus into the tumor (kp) was determined at 0.06 (12.98%RSE). The kg in patients was calculated from the doubling time of TV in naturally progressing HCC patients, and was determined at 0.004day-1. Model-predicted and observed PFS were in good agreement for placebo and everolimus-treated patients. In conclusion, a multiscale QSP/PK/PD model elucidating everolimus lack of efficacy in HCC patients was successfully developed and predicted PFS reasonably well compared to observed clinical findings. This model may provide insights into clinical response to everolimus-based therapy and serve as a valuable tool for the clinical translation of efficacy for novel mTOR inhibitors.

C21 steroid-enriched fraction refined from Marsdenia tenacissima inhibits hepatocellular carcinoma through the coordination of Hippo-Yap and PTEN-PI3K/AKT signaling pathways.

Marsdenia tenacissimae extraction (MTE), a traditional herbal medicine, has exhibited anti-tumor effects on a variety of cancers. However, its effectiveness and the mechanism of action in Hepatocellular carcinoma (HCC) has not been fully understood. In the present study, we demonstrate that C21 steroid-enriched fraction from MTE, which contains five main C21 steroids (FR5) exhibits obvious pharmacological activities on HCC cells in vitro and in vivo. FR5 induces apoptosis and inhibits proliferation and migration of HepG2 and Bel7402 cells in a dose and time dependent manner. Furthermore, in HCC cells, we found that FR5 inhibits Hippo pathway, leading to inactivation of YAP and increase of PTEN. Enhanced PTEN results in the inhibition of PI3K/AKT signaling pathway, inhibiting cell proliferation by FR5 and FR5-induced apoptosis. Moreover, it was proved that FR5 treatment could inhibit tumor growth in a HCC xenograft mouse model, and immunohistochemistry results showed FR5 treatment resulted in down-regulation of Bcl-2 and YAP, and up-regulation of PTEN and PI3K. Taken together, we found that FR5 effectively inhibits proliferation and induces apoptosis of HCC cells through coordinated inhibition of YAP in the Hippo pathway and AKT in the PI3K-PTEN-mTOR pathway, and suggest FR5 as a potential therapy for HCC.

Troxerutin with copper generates oxidative stress in cancer cells: Its possible chemotherapeutic mechanism against hepatocellular carcinoma.

Troxerutin (TXER) a rutin derivative is known for its anticancer effect against hepatocellular carcinoma (HCC). As part of large study, recently we have shown TXER interact with genetic material and its anti-mutagenic property. In the present study we have explored its possible mode of action in HCC. Since TXER alone did not show significant anticancer effect on Huh-7 cells, in vitro biochemical assays were performed for determining anticancer efficacy of TXER + metal complex using transition metals such as Cu, Zn, and Fe. The anticancer efficacy of TXER + Cu on Huh-7 cells were evaluated using MTT assay, DCFDA, JC-1 staining, comet assay, cell cycle analysis, immunocytochemistry, and Western blotting. Non-toxic nature of TXER was analyzed on primary rat hepatocytes. The in vivo efficacy of TXER was tested in N-nitrosodiethylamine initiated and γ-benzene hexachloride and partial hepatectomy promoted rat liver cancer. Liver markers, transition metal levels, histopathological examination, and expression levels of GST-P, 8-OHdG and Ki-67 were studied to assess the in vivo anticancer effect of TXER. We observed that TXER + Cu induced extensive cellular death on Huh-7 cells through generating free radicals and did not possess any toxic effect on normal hepatocytes. The in vivo studies revealed that TXER possess significant anti-cancer effect as assessed through improved liver markers and suppressed GST-P, 8-OHdG, and Ki-67 expression. TXER treatment reduced the hepatic Cu level in cancer bearing animals. Current study brings the putative mechanism involved in anti-cancer effect of TXER, further it will help to formulate phytoconstituents coupled anti-cancer drug for effective treatment of HCC.

LncRNA HULC enhances epithelial-mesenchymal transition to promote tumorigenesis and metastasis of hepatocellular carcinoma via the miR-200a-3p/ZEB1 signaling pathway.

Highly upregulated in liver cancer (HULC), a lncRNA that is considered a key molecule in human liver cancer, has recently been revealed to be involved in hepatocellular carcinoma (HCC) development and progression [1, 2]. It has been reported that HULC can promote tumor invasion and metastasis of HCC, but its function and mechanism of action in HCC have not been elucidated. In this study, we found that HULC was aberrantly up-regulated in HCC tissues and associated with TNM stage, intrahepatic metastases, HCC recurrence, and postoperative survival. HULC depletion inhibited the growth and metastasis of HCC cell lines in vitro and in vivo. Moreover, HULC contributes to ZEB1-induced epithelial-mesenchymal transition (EMT), a requirement for tumor invasion and metastasis that plays a key role in cancer progression. This effect of ZEB1 was inhibited by HULC siRNA. We conclude that the HULC functioned as a competing endogenous RNA (ceRNA) to mediate EMT via up-regulating ZEB1. In this way, it sequesters the miR-200a-3p signaling pathway to facilitate HCC metastasis. HULC comes into play as an oncogene in HCC, acting mechanistically by inducing HCC cells to activate EMT. Such an effect promotes tumor progression and metastasis through the miR-200a-3p/ZEB1 signaling pathway. The identification of this novel pathway that links high expression levels of HULC with EMT in HCC cells may serve as the foundation for the development of novel anti-tumor therapeutics.

TQ inhibits hepatocellular carcinoma growth in vitro and in vivo via repression of Notch signaling.

Thymoquinone (TQ) has been reported to possess anti-tumor activity in various types of cancer. However, its effects and molecular mechanism of action in hepatocellular carcinoma (HCC) are still not completely understood. We observed that TQ inhibited tumor cell growth in vitro, where treatment with TQ arrested the cell cycle in G1 by upregulating p21 and downregulating cyclinD1 and CDK2 expression; moreover, TQ induced apoptosis by decreasing expression of Bcl-2 and increasing expression of Bax. Simultaneously, TQ demonstrated a suppressive impact on the Notch pathway, where overexpression of NICD1 reversed the inhibitory effect of TQ on cell proliferation, thereby attenuating the repressive effects of TQ on the Notch pathway, cyclinD1, CDK2 and Bcl-2, and also diminishing upregulation of p21 and Bax. In a xenograft model, TQ inhibited HCC growth in nude mice; this inhibitory effect in vivo, as well as of HCC cell growth in vitro, was associated with a discernible decline in NICD1 and Bcl-2 levels and a dramatic rise in p21 expression. In conclusion, TQ inhibits HCC cell growth by inducing cell cycle arrest and apoptosis, achieving these effects by repression of the Notch signaling pathway, suggesting that TQ represents a potential preventive or therapeutic agent in HCC patients.

Xanthohumol inhibits Notch signaling and induces apoptosis in hepatocellular carcinoma.

Despite improvement in therapeutic strategies, median survival in advanced hepatocellular carcinoma (HCC) remains less than one year. Therefore, molecularly targeted compounds with less toxic profiles are needed. Xanthohumol (XN), a prenylated chalcone has been shown to have anti-proliferative effects in various cancers types in vitro. XN treatment in healthy mice and humans yielded favorable pharmacokinetics and bioavailability. Therefore, we determined to study the effects of XN and understand the mechanism of its action in HCC. The effects of XN on a panel of HCC cell lines were assessed for cell viability, colony forming ability, and cellular proliferation. Cell lysates were analyzed for pro-apoptotic (c-PARP and cleaved caspase-3) and anti-apoptotic markers (survivin, cyclin D1, and Mcl-1). XN concentrations of 5μM and above significantly reduced the cell viability, colony forming ability and also confluency of all four HCC cell lines studied. Furthermore, growth suppression due to apoptosis was evidenced by increased expression of pro-apoptotic and reduced expression of anti-apoptotic proteins. Importantly, XN treatment inhibited the Notch signaling pathway as evidenced by the decrease in the expression of Notch1 and HES-1 proteins. Ectopic expression of Notch1 in HCC cells reverses the anti-proliferative effect of XN as evidenced by reduced growth suppression compared to control. Taken together these results suggested that XN mediated growth suppression is appeared to be mediated by the inhibition of the Notch signaling pathway. Therefore, our findings warrants further studies on XN as a potential agent for the treatment for HCC.

MicroRNA-195 functions as a tumor suppressor by inhibiting CBX4 in hepatocellular carcinoma.

MicroRNA-195 (miR-195) plays important roles in tumor metastasis and angiogenesis, yet its function and mechanism of action in hepatocellular carcinoma (HCC) remain to be elucidated. In this study, we aimed to confirm whether chromobox homolog 4 (CBX4) is a direct target gene of miR-195 and determine the functions of miR-195 through the CBX4 pathway. miR-195 expression was slightly lower in the HCC tissues compared with that in the adjacent normal tissues. In addition, western blotting and qRT-RCR results showed that both CBX4 mRNA and protein levels were downregulated upon miR-195 overexpression. Luciferase reporter assays revealed that CBX4 is a direct target gene of miR-195. Furthermore, overexpression of CBX4 significantly restored the proliferative, invasive and migratory capacities of the HepG2 cells. Finally, in vivo experiments confirmed that high expression of CBX4 in HepG2 cells promoted tumor growth. In conclusion, our study demonstrated that miR-195 acts as a tumor suppressor by directly targeting CBX4 in HCC. This finding suggests a potential novel strategy for therapeutic interventions of this disease.