Effect of bax, bcl-2 and bcl-xL on regulating apoptosis in tissues of normal liver and hepatocellular carcinoma

The intervention of curcumin on rodent models of hepatic fibrosis: A systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the intervention effect of curcumin on hepatic fibrosis in rodent models through systematic review and meta-analysis, in order to provide meaningful guidance for clinical practice.

METHODS

A systematic retrieval of relevant studies on curcumin intervention in rats or mice hepatic fibrosis models was conducted, and the data were extracted. The outcome indicators included liver cell structure and function related indicators, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), albumin (ALB), ratio of albumin to globulin (A/G), total bilirubin (TBIL), bax protein, bcl-2 protein and index of liver, as well as the relevant indicators for evaluating the degree of hepatic fibrosis, such as hyaluronic acid (HA), laminin (LN), type I collagen (Collagen I), type III collagen (Collagen III), type III procollagen (PCIII), type III procollagen amino terminal peptide (PIIINP), type IV collagen (IV-C), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), α-Smooth muscle actin (α-SMA), hydroxyproline (HYP), platelet derived factor-BB (PDGF-BB), connective tissue growth factor (CTGF) and transforming growth factor-β1 (TGF-β1), and oxidative stress-related indicators, such as superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px). These results were then analyzed by meta-analysis. Studies were evaluated for methodological quality using the syrcle's bias risk tool.

RESULTS

A total of 59 studies were included in the meta-analysis, and the results showed that curcumin can reduce the levels of ALT, AST, ALP, TBIL, bax protein, and index of liver in hepatic fibrosis models. It can also reduce HA, LN, Collagen I, Collagen III, PCIII, PIIINP, IV-C, TNF-α, α-SMA, HYP, PDGF-BB, CTGF, TGF-β1 and MDA, and increase the levels of ALB, A/G, SOD, and GSH-Px in the hepatic fibrosis models. However, the effects of curcumin on bcl-2 protein, IL-6 in hepatic fibrosis models and index of liver in mice were not statistically significant.

CONCLUSION

The analysis results indicate that curcumin can reduce liver cell apoptosis by maintaining the stability of liver cell membrane, inhibit the activation and proliferation of hepatic stellate cells by reducing inflammatory response, and alleviate tissue peroxidation damage by clearing oxygen free radicals.

Protective Effect of Baicalin on Chlorpyrifos-Induced Liver Injury and Its Mechanism

Chlorpyrifos (CPF) plays a vital role in the control of various pests in agriculture and household life, even though some studies have indicated that CPF residues pose a significant risk to human health. Baicalin (BA) is a flavonoid drug with an obvious effect on the prevention and treatment of liver diseases. In this study, the protective effect of BA in vitro and in vivo was investigated by establishing a CPF-induced AML12 cell damage model and a CPF-induced Kunming female mouse liver injury model. The AML12 cell damage model indicated that BA had a good positive regulatory effect on various inflammatory factors, redox indexes, and abnormal apoptosis factors induced by CPF. The liver injury model of female mice in Kunming showed that BA significantly improved the liver function indexes, inflammatory response, and fibrosis of mice. In addition, BA alleviated CPF-induced AML12 cell damage and Kunming female mouse liver injury by enhancing autophagy and regulating apoptosis pathways through Western blotting. Collectively, these data suggest that the potential mechanism of BA is a multi-target and multi-channel treatment for chlorpyrifos-induced liver injury.

Regulation of apoptosis by ubiquitination in liver cancer

Apoptosis is a programmed cell death process critical to cell development and tissue homeostasis in multicellular organisms. Defective apoptosis is a crucial step in the malignant transformation of cells, including hepatocellular carcinoma (HCC), where the apoptosis rate is higher than in normal liver tissues. Ubiquitination, a post-translational modification process, plays a precise role in regulating the formation and function of different death-signaling complexes, including those involved in apoptosis. Aberrant expression of E3 ubiquitin ligases (E3s) in liver cancer (LC), such as cellular inhibitors of apoptosis proteins (cIAPs), X chromosome-linked IAP (XIAP), and linear ubiquitin chain assembly complex (LUBAC), can contribute to HCC development by promoting cell survival and inhibiting apoptosis. Therefore, the review introduces the main apoptosis pathways and the regulation of proteins in these pathways by E3s and deubiquitinating enzymes (DUBs). It summarizes the abnormal expression of these regulators in HCC and their effects on cancer inhibition or promotion. Understanding the role of ubiquitination in apoptosis and LC can provide insights into potential targets for therapeutic intervention.

CCT6A knockdown suppresses osteosarcoma cell growth and Akt pathway activation in vitro

We assessed the role of the protein-coding gene chaperonin-containing TCP1 subunit 6A (CCT6A) in osteosarcoma, as this is currently unknown. Using data from the R2 online genomic analysis and visualization application, we found that CCT6A messenger ribonucleic acid (RNA) expression is increased in osteosarcoma tissue and cells. Transfection of CCT6A small interfering RNA into cultured osteosarcoma cells revealed that CCT6A knockdown attenuates cell growth, cell viability, cell survival, and induced apoptosis and cell cycle progression at the G0/G1 phases. Moreover, CCT6A knockdown downregulated phospho-protein kinase B (p-Akt), cyclinD1 and B-cell lymphoma-2, whereas upregulated Bcl-2-associated X-protein expression. Thus, CCT6A knockdown inhibits cell proliferation, induces cell apoptosis, and suppresses the Akt pathway.

Isatin Counteracts Diethylnitrosamine/2-Acetylaminofluorene-Induced Hepatocarcinogenesis in Male Wistar Rats by Upregulating Anti-Inflammatory, Antioxidant, and Detoxification Pathways

Hepatocellular carcinoma (HCC) represents around 85% of all known types of liver cancers and is estimated to be the fifth most common cause of cancer-related death worldwide. The current study assessed the preventive efficacy of isatin on diethylnitrosamine (DENA)/2-acetylaminofluorene (2-AAF)-induced hepatocarcinogenesis in male Wistar rats and investigated the underlying cellular and molecular mechanisms. HCC was initiated by intraperitoneal injection of DENA (150 mg/kg/week) for two weeks, followed by oral 2-AAF (20 mg/kg) every other day for three successive weeks. Oral isatin or vehicle (control) was administered at 25 mg/kg for 20 weeks during and following HCC induction. Isatin ameliorated the deleterious effects of DENA/2-AAF on liver function as evidenced by reduced serum levels of AST, ALT, total bilirubin, albumin, and liver tumor biomarkers (CA19.9 and AFP) compared to control DENA/2-AAF-treated rats. Histopathological evaluations demonstrated that isatin-mediated protection against hepatocarcinogenesis was accompanied by a decline in hepatic lipid peroxidation, a marker of oxidative stress, and enhanced antioxidant capacity, as evidenced by increased glutathione and superoxide dismutase expression. Isatin treatment also upregulated expression of the major stress-response transcription factor Nrf2 and the detoxifying enzymes NAD(P)H quinine oxidoreductase and glutathione-S-transferase alpha 2 and downregulated expression of the proliferation marker Ki67. Moreover, isatin significantly reduced the DENA/2-AAF-induced decrease in hepatic expression of anti-apoptotic Bcl2 and the DENA/2-AAF-induced increases in pro-inflammatory and pro-apoptotic factors (TNF-α, NF-κB p50, NF-κB p65, p53, and caspase 3). Thus, it can be concluded that isatin may protect against chemically induced hepatocarcinogenesis by enhancing cellular antioxidant, anti-inflammatory, and detoxification mechanisms, in part through upregulation of the Nrf2 signaling pathway.

Induction of Apoptosis by Metabolites of Rhei Radix et Rhizoma (Da Huang): A Review of the Potential Mechanism in Hepatocellular Carcinoma

Liver cancer is a global disease with a high mortality rate and limited treatment options. Alternations in apoptosis of tumor cells and immune cells have become an important method for detailing the underlying mechanisms of hepatocellular carcinoma (HCC). Bcl-2 family, Caspase family, Fas and other apoptosis-related proteins have also become antagonistic targets of HCC. Da Huang (Rhei Radix et Rhizoma, RR), a traditional Chinese herb, has recently demonstrated antitumor behaviors. Multiple active metabolites of RR, including emodin, rhein, physcion, aloe-emodin, gallic acid, and resveratrol, can successfully induce apoptosis and inhibit HCC. However, the underlying mechanisms of these metabolites inhibiting the occurrence and development of HCC by inducing apoptosis is complicated owing to the multi-target and multi-pathway characteristics of traditional Chinese herbs. Accordingly, this article reviews the pathways of apoptosis, the relationship between HCC and apoptosis, the role and mechanism of apoptosis induced by mitochondrial endoplasmic reticulum pathway and death receptor pathway in HCC and the mechanism of six RR metabolites inhibiting HCC by inducing apoptosis.

Phosphorylation of PI3K/Akt at Thr308, but not MAPK kinase, mediates lithium-induced neuroprotection against cerebral ischemia in mice

Lithium, in addition to its effect on acute and long-term bipolar disorder, is involved in neuroprotection after ischemic stroke. Yet, its mechanism of action is still poorly understood, which was only limited to its modulatory effect on GSK pathway. Therefore, we initially analyzed the dose-dependent effects of lithium on neurological deficits, infarct volume, brain edema and blood-brain barrier integrity, along with neuronal injury and survival in mice subjected to focal cerebral ischemia. Thereafter, we investigated the involvement of the PI3K/Akt and MEK signal transduction pathways and their components. Our observations revealed that 2 mmol/kg lithium significantly improved post-ischemic brain tissue survival. Although, 2 mmol/kg lithium had no negative effect on brain microcirculation, 5 and 20 mmol/kg lithium reduced brain perfusion. Furthermore, supratherapeutic dose of lithium in 20 mmol/kg lead to animal death. In addition, improvement of brain perfusion with L-arginine, did not change the effect of 5 mmol/kg lithium on brain injury. Additionally, post-stroke blood-brain barrier leakage, hemodynamic impairment and apoptosis have been reversed by lithium treatment. Interestingly, lithium-induced neuroprotection was associated with increased phosphorylation of Akt at Thr308 and suppressed GSK-3β phosphorylation at Ser9 residue. Lithium upregulated Erk-2 and downregulated JNK-2 phosphorylation. To distinguish whether neuroprotective effects of lithium are modulated by PI3K/Akt or MEK, we sequentially blocked these pathways and demonstrated that the neuroprotective activity of lithium persisted during MEK/ERK inhibition, whereas PI3K/Akt inhibition abolished neuroprotection. Collectively, we demonstrated lithium exerts its post-stroke neuroprotective activity via the PI3K/Akt pathway, specifically via Akt phosphorylation at Thr308, but not via MEK/ERK.

Standardization of diethylnitrosamine-induced hepatocellular carcinoma rat model with time based molecular assessment

This study was intended (1) to develop a robust animal model for hepatocellular carcinoma (HCC) research, in which HCC tumors develop in a background of fibrosis or cirrhosis; and (2) to explore time-dependent regulatory changes in key molecular markers during disease advancement and HCC development. With the aim of establishing such HCC model, male Sprague-Dawley rats were injected with diethylnitrosamine (DEN) at a dose of 30 mg/kg twice a week for 10 weeks then once a week from 12th to 16th weeks. The rats were kept under observation until 18th week. At defined time intervals (2nd, 4th, 12th, and 18th week), serum biomarkers and microscopic components of tissue samples were used to investigate the chronic progression of liver disease, while gene and protein analysis was used to monitor expression patterns during HCC development. DEN-intoxicated rats manifested inflammation at week 4, fibrosis at week 12 and cirrhosis with early HCC tumors at week 18. Molecular analysis revealed that key markers of inflammation (Il-1β, Il-6, and Tnf-α), fibrosis (Tgf-β1, Col1α1, Col3α1, and Timp-1), and angiogenesis (Hif1-α and Vegf) were promptly (P ≤ 0.001) up-regulated at week 4, week 12 and week 18, respectively. Oxidative stress (iNos, Cyp2e1, and Sod1) and pro-apoptotic (Bax) markers showed significant upregulation from week 4 to week 12. However, Sod1 and Bax expressions dropped after week 12 and reached a minimum at 18th week. Strikingly, expressions of anti-apoptotic (Bcl-2) and cell proliferation (Pcna, Hgf, and Afp) markers were abruptly increased at week 18. Collectively, we describe an 18-week HCC model in DEN-intoxicated rats that exhibit chronic inflammation, oxidative imbalance, advance fibrosis/cirrhosis, halted apoptosis, and angiogenic sprouting, progressively.

SOX2 and Bcl-2 as a Novel Prognostic Value in Hepatocellular Carcinoma Progression

Sex-determining region Y-box 2 (SOX2) is a stem cell transcription factor and a major regulator of self-renewal and pluripotency of cancer stem cells (CSCs). In many types of cancer, SOX2 is dysregulated due to overexpression associated with tumor progression and low survival rate. Many HCC cases encounter recurrence and metastasis which might be due to CSCs and also apoptosis. Since little is known about the expression pattern of SOX2 and apoptotic genes in HCC, we aimed to determine the prognostic significance of SOX2, Bax, and Bcl-2 in clinicopathological features, tumor progression, and survival rate of the HCC patients. The expression of SOX2, Bax, and Bcl-2 were evaluated using qRT-PCR in 53 formalin-fixed, paraffin-embedded tissues (FFPE) of patients and 44 controls. Correlation of these genes was analyzed with clinicopathological features and tumor progression. The correlationship between SOX2 expression and ALBI grade as prognostic indicators were calculated. Survival rates were determined by Kaplan–Meier survival curves. SOX2 and Bcl-2 were remarkably overexpressed in HCC patients compared to controls (p = 0.04 and p = 0.003, respectively). A significant association was found for both SOX2 and Bcl-2 overexpression with TNM staging (p = 0.02, p = 0.04) and tumor grading (p = 0.01, p = 0.003), respectively. A significant correlation was observed: patients with SOX2 overexpression had a lower 5-year overall survival rate (p = 0.04); however, there was no significant association between Bcl-2 and survival (p = 0.5). Collectively, overexpression of SOX2 and Bcl-2, alone or combined, may be a potential marker to evaluate prognosis and response to HCC treatment.

A novel platform for drug testing: Biomimetic three-dimensional hyaluronic acid-based scaffold seeded with human hepatocarcinoma cells

Hepatic cancer is one of the most widespread maladies worldwide that requires urgent therapies and thus reliable means for testing anti-cancer drugs. The switch from two-dimensional (2D) to three-dimensional (3D) cell cultures produced an improvement in the in vitro outcomes for testing anti-cancer drugs. We aimed to develop a novel hyaluronic acid (HA)-based 3D cell model of human hepatocellular carcinoma (HepG2 cells) for drug testing and to assess comparatively in 3D vs. 2D, the cytotoxicity and the apoptotic response to the anti-tumor agent, cisplatin. The 3D model was developed by seeding HepG2 cells in a HA/poly(methylvinylether-alt-maleic acid) (HA³P50)-based scaffold. Compared to 2D, the cells grown in the HA³P50 scaffold proliferate into larger-cellular aggregates that exhibit liver-like functions by controlling the release of hepatocyte-specific biomarkers (albumin, urea, bile acids, transaminases) and the synthesis of cytochrome-P450 (CYP)7A1 enzyme. Also, growing the cells in the scaffold sensitize the hepatocytes to the anti-tumor effect of cisplatin, by a mechanism involving the activation of ERK/p38α-MAPK and dysregulation of NF-kB/STAT3/Bcl-2 pathways. In conclusion, the newly developed HA-based 3D model is suitable for chemotherapeutic drug testing on hepatocellular carcinoma. Moreover, the system can be adapted and employed as experimental platform functioning as a proper tissue/tumor surrogate.

The Apoptotic Effect of Trichinella spiralis Infection Against Experimentally Induced Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the sixth most common type of cancer. Prognosis of HCC remains unsatisfactory. Therefore, developing new therapeutic modalities is still mandatory. Tumor biotherapy is a novel concept developed as a therapeutic strategy for cancer treatment. There is a similarity between the regulatory mechanism of Trichinella spiralis nurse cell formation and tumor cell apoptosis signal regulation.

OBJECTIVES

Induction of apoptosis by T. spiralis can represent a new strategy for tumor treatment.

METHODS

Experimental animals were divided in four groups; negative control (GI), T. spiralis infected (GII), induced HCC (GIII) and HCC then infected with T. spiralis (GIV). The apoptotic effect of T. spiralis infection was assessed by histopathological and immunohistochemical staining of B-cell lymphoma 2 (Bcl-2).

RESULTS

We found higher survival rate of rats and decreased weight of their livers with no nodules in HCC- T. spiralis group as compared to HCC group. Improvement of the dysplastic changes and increased apoptotic bodies which was confirmed by decreased expression of Bcl-2 reported in HCC- T. spiralis group.

CONCLUSION

Trichinella-induced apoptosis can be a contributing mechanism of the anti-tumor effect of T. spiralis infection. Our results showed a certain level of decreased progression of the tumor in HCC-T. spiralis group as indicated by increased rate of apoptosis and subsequently had a positive impact on the survival of rats.
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SEC61G plays an oncogenic role in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the most aggressive malignant diseases and requires more effective prevention and treatment strategies. Mutations or overexpression of endoplasmic reticulum (ER) proteins have been frequently identified in a solid tumor, suggesting that ER proteins play an important role in tumor development. SEC61G, a component of Sec61 complex located in the membrane of the human ER, has been revealed a potential relevance in glioblastoma multiforme. Analyses from TCGA database showed that SEC61G was overexpressed in HCC. Additionally, the expression of SEC61G mRNA was associated with the survival time of HCC patients. We verified that the higher expression of SEC61G in HCC tissues than paracancerous tissues. Moreover, knockdown of SEC61G inhibited cell proliferation and induced cell apoptosis in vitro. Besides, SEC61G was required for cell migration and invasion, conferring a potential role for SEC61G in tumor transfer. Taken together, our results revealed the role of SEC61G in HCC cells. Further detailed understanding of the signaling networks underlying SEC61G involvement in HCC cells would make SEC61G as a viable therapeutic target for pharmaceutical intervention of HCC.

An unbiased lipidomics approach identifies key lipid molecules as potential therapeutic targets of Dohongsamul-tang against non-alcoholic fatty liver diseases in a mouse model of obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Dohongsamul-tang (DST) is a traditional herbal formula used to promote the blood circulation and inhibit inflammation, and also widely has been used in the treatment of patients with chronic liver diseases in Korea and China.

AIM OF THE STUDY

This study aimed to investigate the effect of DST on regulation of lipid metabolism of chronic liver diseases in mouse model of non-alcoholic fatty liver diseases (NAFLD).

MATERIALS AND METHODS

In this study, we evaluated the effect of DST on high-fat and high-cholesterol diet (HFHC, 40% fat and 1% cholesterol)-induced NAFLD, and applied unbiased lipidomics using ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF MS) coupled with multivariate analysis.

RESULTS

DST improved hepatic morphology and reduced levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). In addition, DST inhibited hepatic lipid accumulation through the downregulation of C/EBPα, PPARγ, and pAMPK. To further elucidate the effect of DST on hepatic lipid metabolism, we applied UPLC/Q-TOF MS-based lipidomics. The score plots of partial least squares-discriminant analysis (PLS-DA) showed that DST changed the lipid metabolic pattern of high-fat and high-cholesterol diet (HFHC) mice. Twenty-two lipid metabolites were selected as biomarkers regulated by DST and pathway analysis revealed that sphingolipid metabolism and glycerophospholipid metabolism were associated with the effect of DST on NAFLD. Among the 22 selected biomarkers, 14 were phospholipids, and DST significantly reversed the increased expression of lysophospholipase 3 (LYPLA3) and neuropathy target esterase (NTE), which are key enzymes in glycerophospholipid metabolism. Given that alterations in sphingolipids and phospholipids can have effects on apoptosis and insulin resistance (IR), we subsequently investigated changes in the expression of apoptosis-related proteins, including Bcl-2-associated X protein (Bax) and B-cell lymphoma 2 (Bcl2), and IR-related markers after DST treatment. We accordingly found that the ratio of Bax to Bcl-2 expression, a maker of apoptosis, was also elevated in HFHC mice and reduced by DST treatment. In addition, DST enhanced hepatic insulin signaling by upregulating the expression of insulin receptor substrate 1 (IRS-1) and phospho-protein kinase B (pAKT), and oral glucose tolerance test (OGTT) analysis indicated that this herbal preparation also ameliorated systemic IR.

CONCLUSIONS

This study suggested that DST might have an effect on NAFLD by regulating the metabolism of lipids such as phospholipids and sphingolipids and demonstrated that lipidomic profiling is useful to investigate the therapeutic effects of herbal decoctions from traditional Korean and Chinese medicine.

Combined Extracts of Epimedii Folium and Ligustri Lucidi Fructus with Budesonide Attenuate Airway Remodeling in the Asthmatic Rats by Regulating Apoptosis and Autophagy

This study aimed to investigate the effects of the coadministration of budesonide (Bud) and the extracts of Epimedii Folium and Ligustri Lucidi Fructus (EEL) on regulating apoptosis and autophagy in asthmatic rats. Forty Sprague-Dawley rats were divided randomly into five groups (8 rats in each group): normal control (control), asthma model (asthma), Bud (1 mg Bud suspension in 50 ml sterile physiological saline for 30 min), EEL (100 mg/kg EEL), and group of coadministration of Bud and EEL (Bud&EEL, 100 mg/kg EEL plus Bud by nebulized inhalation for 30 min). Rats were sensitized and challenged with ovalbumin for 7 weeks and treated with corresponding drug for 4 weeks. We anesthetized all rats with 25% ethyl carbamate (4 ml/kg) and took lung tissues and BALF after final ovalbumin challenge to observe the lung histopathology and morphometry; apoptosis in BALF and lung tissue; protein expressions of Ki-67, α-SMA, cleaved Caspase-3, p-mTOR, and LC3; and protein and mRNA expressions of Bax, Bcl-2, Caspase-3, P53, mTOR, and Beclin-1. Results showed that Bud&EEL could alleviate airway remodeling, inhibit cell proliferation and autophagy in lung tissue, and promote apoptosis in BALF and lung tissue in ovalbumin-induced asthma rats through downregulating the protein expressions of α-SMA and Ki-67, the protein ratio of LC3-II/LC3-I and Bcl-2/Bax, and the protein and mRNA expressions of Bcl-2 and Beclin-1, while upregulating the protein expressions of cleaved Caspase-3 and p-mTOR, and the protein and mRNA expressions of Bax, Caspase-3, P53, and mTOR. Bud&EEL had better effects than single-use Bud on improving airway remodeling, promoting apoptosis, and regulating the expressions of autophagy- and apoptosis-related proteins. This study suggested that the effects of coadministration of EEL and Bud on regulating apoptosis and autophagy were better than those of single-use Bud treatment, and that might be the mechanism of attenuating airway remodeling, providing an alternative therapy for asthma.

The total flavonoid of Eucommia ulmoides sensitizes human glioblastoma cells to radiotherapy via HIF-α/MMP-2 pathway and activates intrinsic apoptosis pathway

Background: As one of the most common and lethal malignant primary brain tumors, glioblastomas (GBMs) are identified as grade IV neoplasms, the most severe grade, according to WHO classification systems. The outcome of surgery against GBMs is limited since its frequent relapse. Radiotherapy is a crucial and widely used treatment after surgery, while the strong radioresistance of GBM cells still becomes a severe problem of radiotherapy. Eucommia ulmoides Oliv. is used for the treatment of various diseases, such as lower blood pressure and inflammation. Purpose: To explore the anti-tumor effect of Eucommia ulmoides Oliv. against GBMs. Methods: Dose-viability assays were performed to examine the anti-tumor effect. Would-healing and transwell assays were carried out to evaluate the migration and invasion ability of GBMs. Cell apoptosis was detected by 33, 258 staining, and the expressions of key proteins were examined by western blot. Results: In this study, we confirmed that the inhibitory effect of the total flavonoid of Eucommia ulmoides on proliferation, migration and invasion of human GBM cells. Its favorable effects inspired us to explore the potential ability in enhancing radiosensitivity of GBM cells. The results demonstrated that it could further induce apoptosis during radiotherapy via intrinsic apoptosis pathway. Besides, it could significantly reduce the malondialdehyde level after radiotherapy, which suggested it inhibited tumor cell and protected normal neuronal cells. By examining the expression of important genes of radioresistant pathway, we found a significant decrease of HIF-α/MMP-2 when using the total flavonoid of Eucommia ulmoides during radiotherapy. Conclusion: This result suggests that the enhancement of radiotherapy may be mediated by modulating glucose metabolism of GBMs in HIF-α/MMP-2 pathway.

Genome Damage Sensing Leads to Tissue Homeostasis in Drosophila

DNA repair is a critical cellular process required for the maintenance of genomic integrity. It is now well appreciated that cells employ several DNA repair pathways to take care of distinct types of DNA damage. It is also well known that a cascade of signals namely DNA damage response or DDR is activated in response to DNA damage which comprise cellular responses, such as cell cycle arrest, DNA repair and cell death, if the damage is irreparable. There is also emerging literature suggesting a cross-talk between DNA damage signaling and several signaling networks within a cell. Moreover, cell death players themselves are also well known to engage in processes outside their canonical function of apoptosis. This chapter attempts to build a link between DNA damage, DDR and signaling from the studies mainly conducted in mammals and Drosophila model systems, with a special emphasis on their relevance in overall tissue homeostasis and development.

Ziziphus spina-christi leaves methanolic extract alleviates diethylnitrosamine-induced hepatocellular carcinoma in rats

This study evaluated the antitumor activity of a methanolic extract from the leaves of Ziziphus spina-christi (ZSCL) against diethylnitrosamine (DENA)-induced hepatocarcinoma in rats. The phytochemical constituents, in vitro antioxidant and cytotoxic activities of ZSCL extract were investigated. Male Wistar rats were distributed among 6 groups: (i) normal control; (ii) ZSCL1-treated rats (100 mg/kg body mass; "b.m."); (iii) ZSCL2-treated rats (300 mg/kg b.m.); (iv) rats with DENA-induced hepatocarcinoma; (v and vi) rats with hepatocarcinoma that were treated with either (v) ZSCL1 or (vi) ZSCL2. Serum liver function and levels of oxidative stress were assayed. The expression of hepatocyte growth factor, insulin-like growth factor-1 receptor, B cell lymphoma-2, and matrix metalloproteinase-9 oncogenes were quantified in liver samples. Histological examination of the liver tissues was performed. The ZSCL was rich in essential fatty acids, phytol, and polyphenolic flavones (luteolin and quercetin) with strong free-radical and peroxide scavenging activities and cytotoxic activity. Administration of ZSCL1 and ZSCL2 to the rats produced no toxic effects. DENA induced hepatocellular carcinoma and cholangioma by producing oxidative stress and upregulating the expression of hepatic oncogenes. Treatment of DENA-induced hepatocarcinoma with ZSCL2 ameliorated all of the abnormalities induced by DENA except for cholangioma. In conclusion, the ZSCL (300 mg/kg b.m.) displayed strong therapeutic activity against DENA-induced hepatocellular carcinoma via targeting oxidative stress and oncogenes.

Novel pregnenolone derivatives modulate apoptosis via Bcl-2 family genes in hepatocellular carcinoma in vitro

A series of pregnenolone derivatives were synthesized and assessed for anti-cancer activity against hepatocellular carcinoma cell line (HepG2). The synthesized hetero-steroids (compounds 3, 4, 5, 6, 7, 8a and 8b) were evaluated for their cytotoxic activities using MTT (3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) assay. Apoptotic activity was assessed using dual acridine orange/ethidium bromide staining method and DNA fragmentation assay. Pro-apoptotic genes (Bax and Bak) and anti-apoptotic genes (Bcl-2 and Bcl-xL) were analyzed using quantitative real time PCR. The results revealed that compounds 4 and 6 displayed cytotoxic activity (IC_50s, 36.97 ± 2.18 and 18.46 ± 0.64 μM, respectively), while compounds 5 and 7 exhibited weak cytotoxic activity (IC_50s, 93.87 ± 8.30 μM and 93.48 ± 4.14 μM, respectively). All synthesized heterocyclic pregnenolone derivatives induced apoptosis through DNA fragmentation. Compounds 4 and 6 increased early and late apoptotic cell percentages while compounds 3, 5, 7 and 8b increased either early or late apoptotic cell percentage. Moreover, compounds 3, 6 and 8b up-regulated the expression level of Bak gene. On the other hand, compounds 4, 5, 7 and 8a down-regulated the Bcl-2 expression level, besides, compounds 5, 7 and 8a down-regulated the Bcl-xL expression level. Compounds 5, 7, 8a and 8b increased the Bak/Bcl-xL ratio, besides, compound 8a raised the Bax/Bcl-xL ratio whereas compound 5 elevated Bax/Bcl-2 and Bak/Bcl-2 ratios. The present work introduced novel pro-apoptotic pregnenolone derivatives that acted against HepG2 cells through DNA fragmentation, apoptotic morphological changes and were able to increase the pro-apoptotic/anti-apoptotic ratios of Bcl-2 family genes. This study particularly revealed that the cytotoxic compound 4 is the most promising pro-apoptotic compound among other synthesized derivatives where it induced apoptosis (late and early) through the down-regulation of Bcl-2 gene expression level.

Curcumin enhances the antitumor effect of ABT-737 via activation of the ROS-ASK1-JNK pathway in hepatocellular carcinoma cells

At present, the therapeutic treatment strategies for patients with hepatocellular carcinoma (HCC) remain unsatisfactory, and novel methods are urgently required to treat this disease. Members of the B cell lymphoma (Bcl)-2 family are anti‑apoptotic proteins, which are commonly expressed at high levels in certain HCC tissues and positively correlate with the treatment resistance of patients with HCC. ABT-737, an inhibitor of Bcl-2 anti-apoptotic proteins, has been demonstrated to exhibit potent antitumor effects in several types of tumor, including HCC. However, treatment with ABT-737 alone also activates certain pro-survival signaling pathways, which attenuate the antitumor validity of ABT-737. Curcumin, which is obtained from Curcuma longa, is also an antitumor potentiator in multiple types of cancer. In the present study, the synergistic effect of curcumin and ABT-737 on HCC cells was investigated for the first time, to the best of our knowledge. It was found that curcumin markedly enhanced the antitumor effects of ABT-737 on HepG2 cells, which was partially dependent on the induction of apoptosis, according to western blot analysis and flow cytometric apoptosis analysis. In addition, the sustained activation of the ROS-ASK1-c-Jun N-terminal kinase pathway may be an important mediator of the synergistic effect of curcumin and ABT-737. Collectively, these results indicated that the combination of curcumin and ABT-737 can efficaciously induce the death of HCC cells, and may offer a potential treatment strategy for patients with HCC.

Downregulation of SNAIL sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis by regulating the NF-κB pathway

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the second most lethal cancer worldwide. Evidence has shown HCC cell resistance to TRAIL‑mediated apoptosis. In a previous study, we verified that silencing SNAIL downregulated the growth of HCC cells. In addition, the mechanism of resistance to TRAIL in HCC cells was connected with the activation of nuclear factor-κB (NF-κB). Thus, it was hypothesized that the downregultaion of SNAIL sensitizes HCC cells to TRAIL-induced apoptosis by regulating the NF-κB pathway. In the present study, the most effective lentiviral vectors carrying shRNA against SNAIL were selected and adenoviral vectors harboring TRAIL were constructed. The expression of SNAIL and TRAIL was detected by quantitative PCR and western blotting. HCC cell viability and apoptosis were assessed using an MTT assay and the Hoechst test. To determine how to sensitize HCC cells to TRAIL-induced apoptosis after silencing SNAIL, p53 was assessed by western blot analysis. We also investigated the expression of Bcl-xL, cIAP2, survivin and Raf-1 protein using western blot analysis and the apoptotic degree of HuH-7 cells was detected using the Hoechst test following the suppression of each gene, which was a possible molecular mechanism to sensitive TRAIL-induced apoptosis through the downregulation of SNAIL in HCC cells. Silencing SNAIL resulted in increased apoptosis by enhancing sensitization to TRAIL in all the HCC cells. Additionally, p53 protein was upregulated in HuH-7 cells. Expression of Bcl-xL, cIAP2, survivin and Raf-1 was downregulated following silencing of SNAIL, while down-regulation of any of the proteins contributed to SNAIL suppression enhancing HCC cell sensitivity to TRAIL‑induced apoptosis, with the exception of cIAP2. The results demonstrated that silencing SNAIL can sensitize TRAIL-induced apoptosis in HCC cells by upregulating p53 protein and by regulating related genes of the NF-κB pathway such as Bcl-xL, survivin and Raf-1.

MicroRNAs in liver cancer: a model for investigating pathogenesis and novel therapeutic approaches

MicroRNAs (miRNAs) constitute a large class of short RNAs (e.g., 20-24 nucleotides in length), whose main function is to posttranscriptionally regulate the expression of protein-coding genes. Their importance in tumorigenesis has been demonstrated over the past decade, and correspondingly, they have emerged as potential therapeutic molecules and targets. Liver cancer is one of the most common neoplastic diseases worldwide, and it currently has a poor prognosis owing to largely ineffective therapeutic options. Liver cancer is also an excellent model for testing miRNA-based therapy approaches as it can be easily targeted with the systemic delivery of oligonucleotides. In recent years, the role of miRNAs in hepatocellular carcinoma (HCC) has been established with molecular studies and the development of animal models. These studies have also provided the basis for evaluating the therapeutic potential of miRNAs, or anti-miRNAs. In general, the safety of miRNAs has been proven and antitumor activity has been observed. Moreover, because of the absence or presence of mild side effects, the prophylactic use of miRNA-based approaches may be foreseen.

Doenjang prepared with mixed starter cultures attenuates azoxymethane and dextran sulfate sodium-induced colitis-associated colon carcinogenesis in mice

BACKGROUNDS

Doenjang is traditional Korean fermented soybean paste and widely known for its various health benefits including anticancer effect. In this study, we manufactured doenjang with the grain-type meju using probiotic mixed starter cultures of Aspegillus oryzae, Bacillus subtilis-SKm, and Lactococcus lactis-GAm to improve the qualities and beneficial properties of doenjang.

MATERIALS AND METHODS

The inhibitory effects of the doenjang prepared with the grain-type meju using mixed starter cultures were investigated in azoxymethane (AOM) and dextran sulfate sodium (DSS)-induced colon carcinogenesis mice model. AOM and DSS colon carcinogenesis was induced in female C57BL/6 mice, and doenjang was orally administered for 4 weeks. Body weight, colon length, and colon weight of mice were determined, and colonic tissues were histologically evaluated. The serum levels of proinflammatory cytokines as well as the expression of inflammation- and apoptosis-related genes in colonic tissue were also analyzed.

RESULTS

Administration of the doenjang using probiotic mixed starter cultures ameliorated the symptoms of colon cancer, and reduced the incidence of neoplasia, and reduced the levels of serum proinflammatory cytokines such as interleukin-6, and tumor necrosis factor-α and inducible nitric oxide synthase and cycloooxygenase-2 expression levels in colonic tissue. In addition, it increased Bax and reduced Bcl-2 expression levels and increased p21 and p53 expression in the colonic tissues.

CONCLUSION

These findings indicate that the doenjang attenuated colon carcinogenesis induced by AOM and DSS by ameliorating the symptoms of colon cancer, reducing the occurrence of neoplasia, regulating proinflammatory cytokine levels, and controlling the expressions of inflammation- and apoptosis-related genes in the colonic tissue.

Effects of treatment with platinum azidothymidine and azidothymidine on telomerase activity and bcl-2 concentration in hepatocellular carcinoma- induced rats

BACKGROUND

Telomerase activity increases in cancer cells. Bcl-2 is an antiapoptotic factor that its concentration grows in many cancer cells including hepato-cellular carcinoma cells. In this study, an attempt was made to investigate the effects of a new synthetic compound, platinum azidothymidine (Pt-AZT) on treatment of rats with Hepatocellular Carcinoma (HCC) and to compare its effects with azidothymidine (AZT) in alteration of telomerase activity and Bcl-2 concentration in HCC.

METHODS

Healthy adult male Wistar rats (n = 100) were randomly divided into 4 groups (A, B, C, and D). Group A contained 25 healthy rats and was considered as the control group. Liver preneoplastic lesions were induced in remaining animals (n = 75) using Solt-Farber resistant hepatocyte protocol. These animals were randomly allocated in groups B, C and D. Group B was negative control (untreated), groups C and D were treated by intraperitoneal injection (IP) of Pt-AZT (0.9 mg/kg/day) and AZT (0.3 mg/kg/day), respectively for 14 days. After the treatment period, telomerase activity and Bcl-2 concentration were determined in the rats' liver.

RESULTS

No HCC was developed in group A, but tumors were present in all other groups. Telomerase activity and Bcl-2 concentration were significantly lower in group C compared to groups B (0.159±0.06 vs. 0.577±0.116 IU/L, p < 0.001, respect-ively and 0.931±0.388 vs. 3.94±0.74 ng/ml, p < 0.001, respectively). Similar results were observed in comparison with group D (0.331±0.06 vs. 0.577±0.116 IU/L, p < 0.001, respectively and 0.931±0.388 vs. 2.94±0.594 ng/ml, respectively). There was a significant negative correlation between telomerase activity and Bcl-2 concentration only in untreated cancer group (p = 0.034).

CONCLUSION

In this study, higher anticancer activity of Pt-AZT in comparison to AZT was demonstrated. It effectively inhibits the growth of liver tumor in rats through extending apoptosis.

Protective effects of lipoic acid and mesna on cyclophosphamide-induced haemorrhagic cystitis in mice

The protective roles of lipoic acid (LA)/vitamin C (VC) and mesna on preventing cyclophosphamide (CYP)-induced haemorrhagic cystitis (HC) were investigated. Swiss mice were divided into five groups randomly. HC was induced by a single dose of CYP injection (150-mg kg(-1) bodyweight). Group I was injected with saline (four times in total) throughout as control group. Group II received CYP and three equal doses of saline. Group III received CYP and three doses of mesna, whereas Group IV (or Group V) received CYP, mesna + two doses of VC (or LA). All injections were performed intraperitoneally. After 24 h of cystitis induction, the bladders were collected for all the experiments. Histological characterization showed that CYP injection resulted in severe HC. Reactive oxygen species (ROS) and thiobarbituric acid reactive substances' levels were increased in CYP group. The activities of antioxidant enzymes, e.g. superoxide dismutase, catalase, glutathione S-transferase and glutathione peroxidase, were inhibited significantly in CYP groups, respectively. In addition, activation of c-jun N-terminal kinases (JNK) and p38 mitogen-activated protein kinase (MAPK) may be involved in the mechanism of CYP-induced HC but not extracellular signal regulated kinases (ERK). Significant suppression of p38 phosphorylation on Group V suggests that LA and mesna may have synergistic beneficial effect. In Groups III-V, all the parameters of HC and oxidative stress were inhibited significantly. Taking together, we found that these results illustrated that ROS play an important role on CYP-induced HC and the administration of LA/VC with mesna may have therapeutic potential against CYP-induced bladder HC.

Protective effect of a marine polyphenol, dieckol against carbon tetrachloride-induced acute liver damage in mouse

In this study, the hepatoprotective effect of dieckol on carbon tetrachloride (CCl4) induced hepatic damages in ICR mice liver was investigated. Mice were randomly divided into 4 groups such as saline treated (negative control), CCl4 treated (positive control), CCl4+dieckol (5mg/kg mouse) and CCl4+dieckol (25mg/kg mouse), respectively. The body weights and survival rates of mice, followed by dieckol treatments were significantly increased compared to the positive control. The level of GOT, GPT and MDA in the serum of the dieckol treated groups were reduced dose dependently than the control, significantly. The antioxidant enzymes including CAT, and GSH-px levels were increased significantly compared to the positive control. However, no significant differences were observed on hepatic histophathological analysis in dieckol treated groups dose dependently. Down-regulation of Bax and up-regulation of Bcl-xl protein expressions were observed in liver tissues of the dieckol administered groups. These results suggested that, dieckol can be developed as a therapeutic agent for liver disease by oxidative stress.

Fluoro-Sorafenib (Regorafenib) effects on hepatoma cells: growth inhibition, quiescence, and recovery

To evaluate the growth-inhibitory properties of the potent multi-kinase antagonist Regorafenib (Fluoro-Sorafenib), which was synthesized as a more potent Sorafenib, a Raf inhibitor and to determine whether similar mechanisms were involved, human hepatoma cell lines were grown in the presence or absence of Regorafanib and examined for growth inhibition. Western blots were performed for Raf targets, apoptosis, and autophagy. Regorafenib inhibited growth of human Hep3B, PLC/PRF/5, and HepG2 cells in a concentration- and time-dependent manner. Multiple signaling pathways were altered, including MAP kinases phospho-ERK and phospho-JNK and its target phospho-c-Jun. There was evidence for apoptosis by FACS, cleavage of caspases and increased Bax levels; as well as induction of autophagy, as judged by increased Beclin-1 and LC3 (II) levels. Prolonged drug exposure resulted in cell quiescence. Full growth recovery occurred after drug removal, unlike with doxorubicin chemotherapy. Regorafenib is a potent inhibitor of cell growth. Cells surviving Regorafenib treatment remain viable, but quiescent and capable of regrowth following drug removal. The reversibility of tumor cell growth suppression after drug removal may have clinical implications.

Hepatitis C virus activates Bcl-2 and MMP-2 expression through multiple cellular signaling pathways

Hepatitis C virus (HCV) infection is associated with numerous liver diseases and causes serious global health problems, but the mechanisms underlying the pathogenesis of HCV infections remain largely unknown. In this study, we demonstrate that signal transducer and activator of transcription 3 (STAT3), matrix metalloproteinase-2 (MMP-2), and B-cell lymphoma 2 (Bcl-2) are significantly stimulated in HCV-infected patients. We further show that HCV activates STAT3, MMP-2, Bcl-2, extracellular regulated protein kinase (ERK), and c-Jun N-terminal kinase (JNK) in infected Huh7.5.1 cells. Functional screening of HCV proteins revealed that nonstructural protein 4B (NS4B) is responsible for the activation of MMP-2 and Bcl-2 by stimulating STAT3 through repression of the suppressor of cytokine signaling 3 (SOCS3). Our results also demonstrate that multiple signaling cascades, including several members of the protein kinase C (PKC) family, JNK, ERK, and STAT3, play critical roles in the activation of MMP-2 and Bcl-2 mediated by NS4B. Further studies revealed that the C-terminal domain (CTD) of NS4B is sufficient for the activation of STAT3, JNK, ERK, MMP-2, and Bcl-2. We also show that amino acids 227 to 250 of NS4B are essential for regulation of STAT3, JNK, ERK, MMP-2, and Bcl-2, and among them, three residues (237L, 239S, and 245L) are crucial for this regulation. Thus, we reveal a novel mechanism underlying HCV pathogenesis in which multiple intracellular signaling cascades are cooperatively involved in the activation of two important cellular factors, MMP-2 and Bcl-2, in response to HCV infection.

Furin overexpression suppresses tumor growth and predicts a better postoperative disease-free survival in hepatocellular carcinoma

Furin is a member of the pro-protein convertase family. It processes several growth regulatory proteins into their active forms, which are critical to tumor progression, metastasis, and angiogenesis. Furin over-expression could occur in liver cancer and a previous study showed that over-expression of furin promoted HepG2 cell invasion in tail vein xenograft models. However, the clinical relevance of furin expression in hepatocellular carcinoma (HCC) remained unknown. Surprisingly, in a postoperative survival analysis for HCC patients, it was found that the tumor/non-tumor (T/N) ratio of furin expression ≥ 3.5 in HCC tissues predicted a better postoperative disease-free survival (DFS) (P = 0.010; log-rank test). Furthermore, subcutaneous xenograft experiments demonstrated a significant suppression effect of tumor growth in the furin-overexpressed xenografts (Huh7-Furin) compared to the mock control. Administration of a synthetic furin inhibitor for inhibition of the pro-protein convertase activity, decanoyl-Arg-Val-Lys-Arg-chloromethylketone (decRVKR-CMK), to the Huh7-Furin xenograft bearing mice restored the repression effect of tumor growth. In contrast, administration of decRVKR-CMK to the mock Huh7 xenograft bearing mice showed no change in growth rate. In conclusion, furin overexpression inhibited HCC tumor growth in a subcutaneous xenograft model and predicted a better postoperative DFS in clinical analysis.

Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid inhibits hepatocellular carcinoma in vitro and in vivo via stabilizing IkBα

Ent-11-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F) isolated from Pteris Semipinnata L is known to inhibit certain tumor cells in vitro. The information on the in vivo effect of 5F is limited and its effect on hepatocellular carcinoma (HCC) is unknown. In this study, the anti-tumor effect of 5F was investigated in a diethylnitrosamine (DEN)-induced mouse HCC model. In addition to therapeutic effect, the potential side effect was monitored. A panel of cultured HCC cells was used to confirm the in vivo data and explore the responsible molecular pathway. The result showed that 5F significantly inhibited the DEN-induced HCC tumors by reducing the number of tumor foci and the volume of tumors. Furthermore, 5F induced the death of cultured HCC cells in dose- and time-dependent manners. The cell death was confirmed to be apoptotic by in vivo and in vitro TUNEL assays. 5F inhibited NF-kB by stabilizing its inhibitor IkBα, reducing the nuclear p65 and inhibiting NF-kB activity. Subsequently it affected the NF-kB downstream molecules with a decrease in anti-apoptotic Bcl-2 and increase in pro-apoptotic Bax and Bak. During the whole period of the experiment, mice receiving 5F appeared to be healthy, though they suffered from a mild degree of hair loss. 5F did not damage liver and renal functions. In conclusion, 5F is effective against HCC with minimal side effects. It induces apoptosis in HCC cells via inhibiting NF-kB, leading to the decrease of Bcl-2 but the increase of Bax and Bak.

Comparison of Helicobacter bilis-Associated Protein Expression in Huh7 Cells Harbouring HCV Replicon and in Replicon-Cured Cells

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Hepatitis B or C infections are the main causes of HCC with hepatitis C being the major risk factor for liver cancer in the developed countries. Recently, complications with bacteria of the genus Helicobacter have been associated with HCV-induced HCC. To further understand the mechanisms leading to the development of HCC in the presence of HCV and/or Helicobacter spp., investigation of the differential protein expression in Huh7 cells harbouring HCV-replicon, and replicon cured-Huh7 cells cocultured with H. bilis was done employing two-dimensional gel electrophoresis and mass spectrometry. In the transfected-Huh7 cells exposed to sublethal inoculum densities of H. bilis, 53 different proteins were identified comprising of 28 upregulated and 16 downregulated proteins including 9 potential protein isoforms; in the cured Huh7 cells, 45 different proteins were identified including 33 upregulated, 8 downregulated and, 9 potential protein isoforms. H. bilis affected the modulation of proteins involved in different pathways of Huh7-derived cells physiology including proteins involved in the progression from dysplasia to neoplasm. The result also indicated that the response of the Huh7-derived cells to the presence of H. bilis depended on whether or not HCV replicon was present.

Survivin inhibition is critical for Bcl-2 inhibitor-induced apoptosis in hepatocellular carcinoma cells

Our study aims to study the therapeutic effects of a novel Bcl-2 inhibitor, ABT-263, on hepatocellular carcinoma (HCC) and to provide primary preclinical data for future clinical trial with ABT-263. In this study we showed that Bcl-xL and survivin were up-regulated in HCC cell lines and human liver cancer tissues. Clinic used ABT-263 single treatment had no apoptotic effects on HCC cells whereas higher doses of ABT-263 did. Interestingly, the combination treatment of ABT-263 with survivin inhibitor YM-155 could result in significant apoptosis in HCC cells. Survivin inhibition through gene silencing significantly enhanced ABT-263 to induce apoptosis in HCC cells. We found that low dose of ABT-263 single treatment resulted in ERK activation and survivin up-regulation, which might be involved in the resistance of HCC cells to ABT-263 since blockade of ERK activation sensitized ABT-263-induced apoptosis. Importantly, ABT-263 and YM-155 combination treatment had no apoptotic effects on normal human hepatocytes. Taken together, these data suggest the combination treatment of Bcl-2 inhibitor and survivin inhibition may have a great potential for liver cancer therapy.

Global gene profiling of spontaneous hepatocellular carcinoma in B6C3F1 mice: similarities in the molecular landscape with human liver cancer

Hepatocellular carcinoma (HCC) is an important cause of morbidity and mortality worldwide. Although the risk factors of human HCC are well known, the molecular pathogenesis of this disease is complex, and in general, treatment options remain poor. The use of rodent models to study human cancer has been extensively pursued, both through genetically engineered rodents and rodent models used in carcinogenicity and toxicology studies. In particular, the B6C3F1 mouse used in the National Toxicology Program (NTP) two-year bioassay has been used to evaluate the carcinogenic effects of environmental and occupational chemicals, and other compounds. The high incidence of spontaneous HCC in the B6C3F1 mouse has challenged its use as a model for chemically induced HCC in terms of relevance to the human disease. Using global gene expression profiling, we identify the dysregulation of several mediators similarly altered in human HCC, including re-expression of fetal oncogenes, upregulation of protooncogenes, downregulation of tumor suppressor genes, and abnormal expression of cell cycle mediators, growth factors, apoptosis regulators, and angiogenesis and extracellular matrix remodeling factors. Although major differences in etiology and pathogenesis remain between human and mouse HCC, there are important similarities in global gene expression and molecular pathways dysregulated in mouse and human HCC. These data provide further support for the use of this model in hazard identification of compounds with potential human carcinogenicity risk, and may help in better understanding the mechanisms of tumorigenesis resulting from chemical exposure in the NTP two-year carcinogenicity bioassay.

FHL2 exhibits anti-proliferative and anti-apoptotic activities in liver cancer cells

FHL2 displays tumor promoting or tumor suppressing activities depending on the types of tumor cells. In this study, we demonstrated that FHL2 overexpression inhibits the proliferation of human HCC cells Hep3B through cell cycle regulation by decreasing cyclin D1 expression while increasing the expressions of p21 and p27. FHL2 overexpression also inhibits migration and invasion of Hep3B cells through the regulation of epithelial-mesenchymal transition. Surprisingly, we also demonstrated an antiapoptotic function for FHL2 overexpression with increased resistance to doxorubicin-induced apoptosis, which indicates the separation of anti-proliferative and anti-apoptotic role of FHL2. Taken together, our results indicate FHL2 could exert anti-apoptotic effect independent of tumor growth suppression.

MicroRNA-221 targets Bmf in hepatocellular carcinoma and correlates with tumor multifocality

Deregulated cell proliferation and apoptosis play a major role in hepatocellular carcinoma (HCC). MicroRNAs participate in the modulation of key molecules linked to hepatocarcinogenesis.

PURPOSE

This study aims to investigate the role of miR-221 in the modulation of Bmf, a proapoptotic BH3-only protein, and to characterize miR-221 contribution to hepatocarcinogenesis through modulation of apoptosis.

EXPERIMENTAL DESIGN

Transfection of miR-221 and anti-miR-221 in HCC-derived cell lines and luciferase reporter assay were used to assess Bmf as a target of miR-221. Modulation of miR-221 and Bmf expression contributed to characterize their role in anoikis. Primary HCC tissues were analyzed to assess the clinical relevance of in vitro findings.

RESULTS

Enforced miR-221 expression caused Bmf down-regulation, whereas anti-miR-221 induced its up-regulation. A luciferase reporter assay confirmed Bmf as a target of miR-221. Following matrix detachment, miR-221 silencing led to increased apoptotic cell death. The analysis of HCC tissues revealed an inverse correlation between miR-221 and Bmf expression and a direct correlation between Bmf and activated caspase-3, as a marker of apoptosis. High miR-221 levels were associated with tumor multifocality and reduced time to recurrence after surgery.

CONCLUSIONS

Our results indicate that miR-221, by targeting Bmf, inhibits apoptosis. Moreover, in HCC, miR-221 overexpression is associated with a more aggressive phenotype. These findings, together with the previously reported modulation of CDKN1B/p27 and CDKN1C/p57, show that miR-221 simultaneously affects multiple pro-oncogenic pathways and suggest miR-221 as a potential target for nonconventional treatment against HCC.

Hepatocellular Carcinoma: Tumorigenesis and Prediction Markers

Hepatocellular carcinoma (HCC) is one of the most common malignancies. Although many advances have been made in the clinical study of HCC, the prognosis remains poor. Despite the discoveries in cancer biology in respect with physiological and pathological factors in relation to prognosis, HCC remains still a fatal disease due to late diagnosis. For improving the outcomes of patients with HCC, it is important to identify the factors predisposing to patient death. In recent years, based on cellular and molecular biology techniques, many tumor markers related to invasion, metastasis, recurrence and survival have been explored. However, routine biomarkers for the prediction of HCC evolution and prognosis are available in small number and less specific. These reviews focus on the recent advances in HCC tumorigenesis, revealing those biomarkers with prognosis significance or can be used for early detection.

MicroRNA involvement in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third cause of cancer-related death worldwide. Curative options for HCC are limited and exclusively available for patients carrying an early stage HCC. In advanced stages, traditional chemotherapy proved to be only marginally effective or even toxic. Thus, the identification of new treatment options is needed. New targets for non-conventional treatment will necessarily take advantage of progresses on the molecular pathogenesis of HCC. MicroRNAs (miRNAs) are a group of tiny RNAs with a fundamental role in the regulation of gene expression. Aberrant expression of several miRNAs was found to be involved in human hepatocarcinogenesis. miRNA expression signatures were correlated with bio-pathological and clinical features of HCC. In some cases, aberrantly expressed miRNAs could be linked to cancer-associated pathways, indicating a direct role in liver tumourigenesis. For example, up-regulation of mir-221 and mir-21 could promote cell cycle progression, reduce cell death and favour angiogenesis and invasion. These findings suggest that miRNAs could become novel molecular targets for HCC treatment. The demonstration of in vivo efficacy and safety of anti-miRNA compounds has opened the way to their use in clinical trials.

Down-regulation of the HGF/MET autocrine loop induced by celecoxib and mediated by P-gp in MDR-positive human hepatocellular carcinoma cell line

Many tumors are resistant to drug-induced cell-cycle arrest and apoptosis. We have reported that apoptosis can be restored in human multidrug-resistant (MDR) hepatocellular carcinoma cell lines by celecoxib. Here we show that P-glycoprotein (P-gp) mediates cell-cycle arrest and autophagy induced by celecoxib in human MDR overexpressing hepatocellular carcinoma cell line by down-regulation of the HGF/MET autocrine loop and Bcl-2 expression. Exposure of cells to a low concentration of celecoxib down-regulated the expression of mTOR and caused G1 arrest and autophagy, while higher concentration triggered apoptosis. Cell growth inhibition and autophagy were associated with up-regulation of the expression of TGFbeta1, p16(INK4b), p21(Cip1) and p27(Kip1) and down-regulation of cyclin D1, cyclin E, pRb and E2F. The role of P-glycoprotein expression in resistance of MDR cell clone to cell-cycle arrest, autophagy and apoptosis was shown in cells transfected with MDR1 small interfering RNA. These findings demonstrate that the constitutive expression of P-gp is involved in the HGF/MET autocrine loop that leads to increased expression of Bcl-2 and mTor, inhibition of eIF2alpha expression, resistance to autophagy/apoptosis and progression in the cell-cycle. Since mTor inhibitors have been proposed in treatment of "drug resistant" cancer, these data may help explain the reversing effect of mTor inhibitors.

MicroRNA gene expression profile of hepatitis C virus-associated hepatocellular carcinoma

MicroRNAs are small noncoding RNAs that regulate gene expression by targeting messenger RNAs (mRNAs) through translational repression or RNA degradation. Many fundamental biological processes are modulated by microRNAs, and an important role for microRNAs in carcinogenesis is emerging. Because understanding the pathogenesis of viral-associated hepatocellular carcinomas is important in developing effective means of classification, prognosis, and therapy, we examined the microRNA expression profiles in a large set of 52 human primary liver tumors consisting of premalignant dysplastic liver nodules and hepatocellular carcinomas by quantitative real-time polymerase chain reaction. All patients were infected with hepatitis C, and most had liver cirrhosis. Initially, the accessibility of microRNAs from formalin-fixed paraffin-embedded archival liver tissue by real-time polymerase chain reaction assays was shown. Subsequently, target parenchyma from routinely processed tissue was macrodissected, RNA was extracted, and reverse transcription followed by quantitative real-time polymerase chain reaction was performed. Relative quantification was performed by the 2(-DeltaDeltaCt) method with normal livers as a calibrator. In order to obtain a comprehensive microRNA gene expression profile, 80 microRNAs were examined in a subset of tumors, which yielded 10 up-regulated and 19 down-regulated microRNAs compared to normal liver. Subsequently, five microRNAs (miR-122, miR-100, miR-10a, miR-198, and miR-145) were selected on the basis of the initial results and further examined in an extended tumor sample set of 43 hepatocellular carcinomas and 9 dysplastic nodules. miR-122, miR-100, and miR-10a were overexpressed whereas miR-198 and miR-145 were up to 5-fold down-regulated in hepatic tumors compared to normal liver parenchyma.

CONCLUSION

A subset of microRNAs are aberrantly expressed in primary liver tumors, serving both as putative tumor suppressors and as oncogenic regulators.

Embryo quality and production efficiency of porcine parthenotes is improved by phytohemagglutinin

In vitro production of porcine embryos has become routine in most laboratories but the yield and quality of the resultant blastocysts remain suboptimal. Phytohemagglutinin (PHA) is an N-acetylgalactosamine/galactose sugar-specific lectin with a wide variety of biological activities including mitogenesis, mediation of cell recognition, and agglutination of cells. This study was therefore, designed to investigate the effect of PHA on the preimplantation embryo development and quality of in vitro produced porcine parthenotes. Parthenogenetic presumptive diploid zygotes were produced in vitro by electrical activation and cultured in the absence or presence of PHA at different concentrations (0, 5, 10, 15, 20 microg/ml). There were no significant differences in the cleavage rate of porcine parthenotes in control and treatment groups at all tested concentrations of PHA (P < 0.05). However, supplementation of PHA at the concentration of 15 microg/ml significantly improved the blastocyst rate (68.9 +/- 1.5% vs. 43.1 +/- 4.1%), hatching rate (25.8 +/- 3.1% vs. 8.9 +/- 2.0%), and total nuclei number (95.5 +/- 9.3 vs. 63.4 +/- 4.3) when compared to control group (P > 0.05). TUNEL labeling revealed that blastocysts in PHA group were less predisposed to biochemical apoptosis than in control group while total apoptosis and nuclear fragmentation remained unaltered. Real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis further revealed that PHA decreased the expression ratio of BAX/BCL-XL and enhanced the relative abundance of IGF2 transcripts. Therefore, our study suggests that PHA improves the blastocyst yield and quality by enhancing blastocyst expansion, hatching, and total cell number and decreasing the apoptosis by positively modulating the expression of embryo survival related genes.

Imbalance in liver homeostasis leading to hyperplasia by overexpressing either one of the Bcl-2-related genes, zfBLP1 and zfMcl-1a

Apoptosis is an essential part of normal embryonic development in vertebrates, and it is involved in sculpturing organs and controlling cell populations. In previous studies, we identified two novel proteins, zfBLP1 and zfMcl-1a, which are similar to those of the Bcl-2 family as a group of evolutionarily conserved proteins that regulate cellular anti-apoptosis. To evaluate the effect of dysregulated hepatocyte apoptosis during zebrafish hepatogenesis, we demonstrate the transgenic overexpression of either zfBLP1 or zfMcl-1a in zebrafish larval liver. Results showed that 18%-43% of larvae overexpressed zfBLP1 and that 16%-37% of larvae overexpressed zfMc1-1a in the liver leading to liver hyperplasia in 5-day postfertilization (dpf) zebrafish larvae. Histologically, zebrafish larvae exhibiting liver hyperplasia displayed a normal type of hepatocyte and the same cell numbers in their two liver buds compared with only one liver bud of wild-type larvae. Of interest, the expression of cyclin genes (A2, B, D1, and E), hepatocyte nuclear factor genes (HNF-1alpha, beta, -3beta, and 4alpha), and oncogenic markers (P53, c-myc, beta-catenin, N-ras, and gankyrin) were up-regulated, while the expression of C/EBP-alpha was down-regulated in a zfMcl-1a-mediated anti-apoptotic process of the liver. Increased cell death and proliferation was found in both hepatic cells of zebrafish larvae overexpressing either zfBLP1 or zfMcl-1a. However, those zebrafish larvae with liver hyperplasia only lived approximately 10 days. (This finding may have been due to liver abnormalities that led to failure of liver function.) In conclusion, transgenic overexpression of zfBLP1 or zfMcl-1a in zebrafish larvae interrupts regulation of the homeostatic balance between cell proliferation and programmed cell death during hepatogenesis and leads to liver hyperplasia.

Diagnostic and prognostic role of alpha-fetoprotein in hepatocellular carcinoma: both or neither?

BACKGROUND

The clinical usefulness of alpha-fetoprotein (AFP) in hepatocellular carcinoma (HCC) management is debatable.

OBJECTIVES

To assess, in a large multi-centric survey, diagnostic and prognostic reliability of AFP, predictive factors, and any correlation with the tumor immunophenotype.

METHODS

A total of 1,158 patients with HCC were analyzed with reference to serum AFP levels at diagnosis. We evaluated: HCC grading, histotype, and size; Okuda, tumor-nodes-metastases (TNM), and Child-Pugh scores; liver function, symptoms, presence of metastases or portal thrombosis, etiology, survival, and treatment. In 66 patients with histological diagnosis, the pathologists evaluated p53 overexpression, MIB 1 labeling index, BCL-2 positive cells (index of apoptosis), and CD44 (adhesion molecule) positivity.

RESULTS

Patients were divided into three AFP groups: normal (<20 ng/mL) [46%], elevated (21-400 ng/mL) [36%], and diagnostic (>400 ng/mL) [18%]. Statistical correlations were significant for: weight loss (p= 0.0056), pain (p= 0.0025), Child-Pugh score (p= 0.001), tumor size, Okuda's and TNM stages, metastases, thrombosis, type of treatment (all p < 0.0001), and female sex (p < 0.004). AFP correlated with survival overall, in patients untreated, transplanted, or undergoing locoregional treatments; but not in those surgically treated. In the discriminant analysis, the related variables were size, female sex, Child-Pugh score, TNM staging (steps 1-4). When using the receiver operating characteristic curve, the prognostic reliability of AFP was limited with area under the curve of 0.59. Finally, patients with low expression of BCL2 had high AFP levels (p < 0.05). AFP positively correlated with Edmonson score (p < 0.0001).

CONCLUSION

The evaluation of this large series of HCC patients allowed us to: confirm the low sensitivity (54%) of AFP in the diagnosis of HCC and its prognostic value, albeit limited, being tumor size, female sex (intriguingly enough), Child-Pugh score, and TNM staging independent predictors.

Expression of Bag-1 and Bcl-2 and its significance in gastric cancer

AIM: To investigate the expression of Bag-1 and Bcl-2 protein and its clinical significance in gastric cancer (GC).

METHODS: Immunohistochemistry was used to detect the expressison of Bag-1 and Bcl-2 protein in 92 patients with gastric cancer and 40 normal tissues as control.

RESULTS: Compared with normal mucosa, Bag-1 and Bcl-2 were over-expressed in gastric cancerous tissues (60.9% vs 7.5%, 72.8% vs 10%, P<0.01). The expression of Bcl-2 protein was significantly correlated with the differentiation degree (r_s = 0.513, P<0.05) and the expression of Bag-1 was significantly associated with Bcl-2 level in gastric cancer (r_s = 0.522, P<0.01).

CONCLUSION: The over-expression of Bcl-2 leads to uncontrolled growth and unceasingly increases of GC cells by accelerating cell transformation and proliferation. Bag-1 promotes the function of Bcl-2 and co-expression of Bag-1 and Bcl-2 may mean poor prognosis of GC patients.

BCL2 and JUNB abnormalities in primary cutaneous lymphomas

BACKGROUND

BCL2 is upregulated in nodal and extranodal B-cell non-Hodgkin's lymphomas, with a consequent antiapoptotic effect. However, loss of BCL2 has also been noted in some malignancies, suggesting a different molecular pathogenesis.

OBJECTIVES

To investigate genomic and protein expression status of BCL2 and to compare the results with that of JUNB in primary cutaneous lymphomas (PCLs).

METHODS

We analysed gene copy number of BCL2 and JUNB in 88 DNA samples from 80 patients with PCL consisting of Sézary syndrome/mycosis fungoides (SS/MF), primary cutaneous B-cell lymphoma (PCBCL) and primary cutaneous CD30+ anaplastic large cell lymphoma (C-ALCL) by the use of real-time polymerase chain reaction (PCR) and immunohistochemistry (IHC). Real-time PCR and IHC findings were subsequently compared with the results of additional fluorescent in situ hybridization (FISH) analysis of 23 cases of SS and Affymetrix cDNA expression microarray study of two primary cutaneous T-cell lymphoma (CTCL) cell lines.

RESULTS

Real-time PCR analysis showed loss of BCL2 gene copy number in 22 of 80 PCL cases (28%), including 17 of 42 SS/MF, three of 13 C-ALCL and two of 33 PCBCL samples, and gain of BCL2 in four PCBCL samples. Gain of JUNB was identified in 18 of 71 PCL cases (25%), including nine of 35 SS/MF, seven of 13 C-ALCL and two of 31 PCBCL samples. IHC analysis revealed absent nuclear expression of BCL2 protein in 47 of 73 PCL cases, comprising 28 of 36 SS/MF, eight of eight C-ALCL and 11 of 29 PCBCL cases. In contrast, BCL2 protein expression was detected in 26 of 73 PCL cases, consisting of 18 of 29 PCBCL and eight of 36 SS/MF cases. JUNB protein expression was present in tumour cells from 30 of 33 of SS/MF and eight of eight C-ALCL, and was absent in tumour cells from 18 of 27 PCBCL cases. A comparison between BCL2 and JUNB revealed loss of BCL2 and gain of JUNB in five of 35 SS/MF samples, and expression of JUNB protein and absent BCL2 expression in 25 SS/MF and eight of eight C-ALCL cases. In contrast, expression of BCL2 and absent JUNB expression were detected in 67% of PCBCL cases. Additional FISH analysis revealed deletion of BCL2 in 19 of 23 SS cases (83%), including eight cases with BCL2 loss shown by real-time PCR. Furthermore, Affymetrix expression microarray demonstrated decreased expression of proapoptotic and antiapoptotic genes involved in BCL2 signalling pathways such as BOK, BIM, HRK, RASA1 and STAT2 in two CTCL cell lines with BCL2 loss and absent BCL2 expression. Increased expression of JUNB was also identified in the MF cell line.

CONCLUSIONS

These findings provide a comprehensive assessment of BCL2 and JUNB status in PCL, and suggest that there is a selection pressure in a subset of CTCL cases for tumour cells showing BCL2 loss and upregulation of JUNB primarily through chromosomal deletion and amplification, respectively.

Alterations of p53, Bcl-2, and hMSH2 protein expression in the cirrhotic, macroregenerative, dysplastic nodules and hepatocellular carcinomas in Upper Egypt

BACKGROUND

Hepatocarcinogenesis involves alterations in p53, Bcl-2 and human Mut S homologue-2 (hMSH2) genes. In Upper Egypt, the clinicopathologic and genetic changes during hepatocarcinogensis (cirrhotic nodules (CN); macroregenerative nodules (MRN) and dysplastic nodules (DN) are unknown.

METHODS

To examine these issues, 48 hepatic resection specimens entailing 25 CN, 16 MRN, 23 DN and 48 hepatocellular carcinoma (HCC) were immunohistochemically evaluated for p53, Bcl-2 and hMSH2 protein expression.

RESULTS

HCC was common in males than in females (2.6:1, P<0.05) and with hepatitis C virus than hepatitis B virus infection (77.1% vs. 18.7%, P=0.001). p53 expression was found in DN (3/23) and HCC (12/48). Its average weighted scores were high in DN/HCC as compared with CN (1.60+/-0.40 and 7.20+/-1.20, P=0.0001). Bcl-2 expression was seen in CN, MRN, DN and HCC (7/48). Its average weighted scores were high in DN (7.60+/-1.60), HCC (6.86+/-0.85) as compared with CN (6.14+/-0.42) and MRN (6.50+/-0.50, P=0.22). hMSH2 average weighted scores were reduced in HCC (7.94+/-1.06) as compared with CN (8.47+/-0.52), MRN (8.00+/-1.00) and DN (8.20+/-0.80, P>0.05).

CONCLUSION

In Upper Egypt: (1) HCC had similar clinicopathologic features to those in the high-risk regions, and (2) alterations of the p53, Bcl-2 and hMSH2 proteins occur during hepatocarcinogensis.

Role of phosphorylation of ser10 of p27Kip1 in its subcellular localization in HepG2 cell lines

AIM: To investigate the influence of over-expression of exogenous p27^kip1 gene on cell cycle and proliferation in HepG₂ cell line, and to elucicate the role of phosphorylation of ser¹⁰ of p27^kip1 protein in its subcellular localization.

METHODS: Both plasmids containing the wild type and S10A p27^kip1 were transfected into HepG₂ cell lines with Lipofectamine separately. The exogenous p27^kip1 protein expression and subcellular localization was monitored with immunoflurescence under laser confocal microscope. Its biological effects on cell cycle and proliferation were determined by FACS and growth curves.

RESULTS: Over-expression of p27^kip1 protein was observed in transfected cells. As a result, the proliferation of HepG₂ cells was greatly inhibited and cell cycle was arrested in G₁ phase after exogenous p27^kip1 expression. Both the wild type and S10A p27^kip1 protein were distributed in the nucleus when synchronized at G₀ phase by serum deprivation for 96 hours. The wild type p27^kip1 protein was translocated from nucleus to cytoplasm when the cell was restimulated by exposure to 20% serum for 8 h, whereas the S10A p27^kip1 still presented in the nucleus.

CONCLUSION: The overexpression of p27^kip1 can inhibit the proliferation of HepG₂, and phosphorylation of p27^kip1 on serine¹⁰is required for its nuclear export.