Involvement of mTOR and survivin inhibition in tamoxifen-induced apoptosis in human hepatoblastoma cell line HepG2

Comparison of Engineered Liver 3D Models and the Role of Oxygenation for Patient-Derived Tumor Cells and Immortalized Cell Lines Cocultured with Tumor Stroma in the Detection of Hepatotoxins

In metabolically active tumors, responses of cells to drugs are heavily influenced by oxygen availability via the surrounding vasculature alongside the extracellular matrix signaling. The objective of this study is to investigate hepatotoxicity by replicating critical features of hepatocellular carcinoma (HCC). This includes replicating 3D structures, metabolic activities, and tumor-specific markers. The internal environment of spheroids comprised of cancerous human patient-derived hepatocytes using microparticles is modulated to enhance the oxygenation state and recreate cell-extracellular matrix interactions. Furthermore, the role of hepatic stellate cells in maintaining hepatocyte survival and function is explored and hepatocytes from two cellular sources (immortalized and patient-derived) to create four formulations with and without microparticles are utilized. To investigate drug-induced changes in metabolism and apoptosis in liver cells, coculture spheroids with and without microparticles are exposed to three hepatotoxic drugs. The use of microparticles increases levels of apoptotic markers in both liver models under drug treatments. This coincides with reduced levels of anti-apoptotic proteins and increased levels of pro-apoptotic proteins. Moreover, cells from different origins undergo apoptosis through distinct apoptotic pathways in response to identical drugs. This 3D microphysiological system offers a viable tool for liver cancer research to investigate mechanisms of apoptosis under different microenvironmental conditions.

Upregulated miR‑378a‑3p expression suppresses energy metabolism and promotes apoptosis by targeting a GLUT‑1/ALDOA/PKM2 axis in esophageal carcinoma

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy of the digestive system with increasing incidence and mortality rates. The biological roles of microRNA (miR)-378a-3p in tumor cells remain contested, and the mechanisms underlying the functions, energy metabolism, and cell survival mechanisms in ESCC cells are yet to be fully elucidated. In the present study, miR-378a-3p overexpression and negative control plasmids were transfected into ECA-109 cells using electroporation. Western blotting was used to detect the relative expression of proteins, and flow cytometry was used to detect cell apoptosis. Subsequently, ELISA assays were performed to determine enzyme activity, and an ATP detection kit was used to measure ATP content. Dual-luciferase reporter assays were performed to identify the target genes of miR-378a-3p. The results of the present study demonstrated that miR-378a-3p inhibited the gene expression and enzyme activities of glucose transporter protein 1 (GLUT-1), Aldolase A (ALDOA), and pyruvate kinase M2 (PKM2), all of which are involved in the glycolytic pathway of cells. Energy metabolism was suppressed by miR-378a-3p by reducing ATP content, and this downregulated the expression of Bcl-2 and Survivin. Moreover, increased miR-378a-3p expression promoted cell apoptosis in the early stages by increasing the expression levels and the activity of Bad and Caspase-3, while inhibiting the expression levels of Bcl-2 and Survivin. The results of the present study also demonstrated that GLUT-1/ALDOA/PKM2 were target genes of miR-378a-3p. Notably, miR-378a-3p blocked energy production and promoted the apoptosis of tumor cells via the downregulation of glycolytic enzyme expression and by reducing the mitochondrial membrane potential in ESCC. Bad, Caspase-3, Survivin, and Bcl-2 may be associated with blocking energy production and promoting apoptosis via miR-378a-3p in ESCC cells.

Naringenin and Quercetin Exert Contradictory Cytoprotective and Cytotoxic Effects on Tamoxifen-Induced Apoptosis in HepG2 Cells

Tamoxifen is commonly used to treat estrogen receptor-positive breast cancer and hepatocellular carcinoma. Phytoconstituents are considered candidates for chemopreventive drugs in cancer treatment. However, it remains unknown what would happen if tamoxifen and phytoconstituents were administrated simultaneously. We aimed to observe the synergistic antitumor effects of tamoxifen and naringenin/quercetin on human hepatic carcinoma and to explore the potential underlying molecular mechanisms. The HepG2 cell line was used as an in vitro model. Cell proliferation, invasion, migration, cycle progression and apoptosis were investigated along with reactive oxygen species (ROS) production and mitochondrial membrane potential (ΔΨm) repression. The signaling pathways involved were identified using real-time quantitative polymerase chain reaction analysis. As the results show, tamoxifen in combination with higher concentrations of naringenin or quercetin significantly inhibited cell growth compared to either agent alone. These antiproliferative effects were accompanied by the inhibition of cell migration and invasion but the stimulation of cell apoptosis and loss of ΔΨm, which depended on the ROS-regulated p53 signaling cascades. Conversely, lower concentrations of naringenin and quercetin inhibited the tamoxifen-induced cell antiproliferative effects by regulating cell migration, invasion, cycle and apoptosis. Taken together, our findings revealed that phytoconstituents exerted contradictory cytoprotective and cytotoxic effects induced by tamoxifen in human hepatic cancer.

Anti-apoptotic proteins in the autophagic world: an update on functions of XIAP, Survivin, and BRUCE

X-linked inhibitor of apoptosis protein (XIAP), survivin, and BRUCE are members of the inhibitor-of-apoptosis protein (IAP) family known for their inhibitory effects on caspase activity and dysregulation of these molecules has widely been shown to cause embryonic defects and to promote tumorigenesis in human. Besides the anti-apoptotic functions, recent discoveries have revealed that XIAP, survivin, and BRUCE also exhibit regulatory functions for autophagy in cells. As the role of autophagy in human diseases has already been discussed extensively in different reviews; in this review, we will discuss the emerging autophagic role of XIAP, survivin, and BRUCE in cancer cells. We also provide an update on the anti-apoptotic functions and the roles in maintaining DNA integrity of these molecules. Second mitochondria-derived activator of caspases (Smac) is a pro-apoptotic protein and IAPs are the molecular targets of various Smac mimetics currently under clinical trials. Better understanding on the functions of XIAP, survivin, and BRUCE can enable us to predict possible side effects of these drugs and to design a more “patient-specific” clinical trial for Smac mimetics in the future.

DPEP1 is a direct target of miR-193a-5p and promotes hepatoblastoma progression by PI3K/Akt/mTOR pathway

Hepatoblastoma (HB) is the most common hepatic neoplasm in childhood and the therapeutic outcomes remain undesirable due to its recurrence and metastasis. Increasing evidence shows that dipeptidase 1 (DPEP1) has pivotal function in tumorigenesis in multiple tumors. However, the expression pattern, biological function, and underlying mechanism of DPEP1 in HB have not been reported. Here we showed that DPEP1 was significantly upregulated and was associated with poor prognosis in HB patients. In vitro and in vivo assays indicated that silencing DPEP1 significantly suppressed HB cell proliferation, migration, and invasion, while DPEP1 overexpression exhibited the opposite effect. In addition, we identified that DPEP1 was a direct target of microRNA-193a-5p (miR-193a-5p). Functional experiments demonstrated that overexpression of miR-193a-5p significantly inhibited cell proliferation and invasion of HB cells, while the inhibitory effect could be reversed by DPEP1 overexpression. Moreover, miR-193a-5p was decreased in HB tumor tissues and associated with a poor clinical prognosis. Mechanistically, our results indicated that the miR-193a-5p/DPEP1 axis participated to the progression of HB via regulating the PI3K/Akt/mTOR (phosphatidylinositol-3-kinase/Akt/mammalian target of rapamycin) signaling. In conclusion, our findings suggest that the miR-193a-5p /DPEP1 axis might be a good prognostic predictor and therapeutic target in HB.

Dihydroisotanshinone I combined with radiation inhibits the migration ability of prostate cancer cells through DNA damage and CCL2 pathway

BACKGROUND

Radiotherapy plays an important role in the treatment of prostate cancer. Despite that sophisticated techniques of radiotherapy and radiation combined with chemotherapy were applied to the patients, some tumors may recur. Therefore, the study investigated the effect of dihydroisotanshinone I (DT) and the combination treatment of 5 μM DT and 5Gy irradiation (IR) against the migration ability of prostate cancer cells.

METHODS

DT and the combination treatment were studied for its biological activity against migration ability of prostate cancer cells with transwell migration assay. Subsequently, we tried to explore the underlying mechanism with ELISA, flow cytometry and Western's blotting assay.

RESULTS

The results showed that DT and the combination treatment substantially inhibited the migration ability of prostate cancer cells. DT and the combined treatment can decrease the ability of macrophages to recruit prostate cancer cells. Mechanistically, DT and the combination treatment reduced the secretion of chemokine (C-C Motif) Ligand 2 (CCL2) from prostate cancer cells. We also found that DT treatment induced the cell cycle of prostate cancer cells entering S phase and increased the protein expression of DNA damage response proteins (rH2AX and phosphorylated ataxia telangiectasia-mutated [ATM]) in DU145 cells and PC-3 cells.

CONCLUSIONS

DT displays radiosensitization and antimigration effects in prostate cancer cells by inducing DNA damage and inhibiting CCL2 secretion. We suggest that DT can be used as a novel antimetastatic cancer drug or radiosensitizer in the armamentarium of prostate cancer management.

HDAC2 and HDAC5 Up-Regulations Modulate Survivin and miR-125a-5p Expressions and Promote Hormone Therapy Resistance in Estrogen Receptor Positive Breast Cancer Cells

Intrinsic or acquired resistance to hormone therapy is frequently reported in estrogen receptor positive (ER⁺) breast cancer patients. Even though dysregulations of histone deacetylases (HDACs) are known to promote cancer cells survival, the role of different HDACs in the induction of hormone therapy resistance in ER⁺ breast cancer remains unclear. Survivin is a well-known pro-tumor survival molecule and miR-125a-5p is a recently discovered tumor suppressor. In this study, we found that ER⁺, hormone-independent, tamoxifen-resistant MCF7-TamC3 cells exhibit increased expression of HDAC2, HDAC5, and survivin, but show decreased expression of miR-125a-5p, as compared to the parental tamoxifen-sensitive MCF7 breast cancer cells. Molecular down-regulations of HDAC2, HDAC5, and survivin, and ectopic over-expression of miR-125a-5p, increased the sensitivity of MCF7-TamC3 cells to estrogen deprivation and restored the sensitivity to tamoxifen. The same treatments also further increased the sensitivity to estrogen-deprivation in the ER⁺ hormone-dependent ZR-75-1 breast cancer cells in vitro. Kaplan-Meier analysis and receiver operating characteristic curve analysis of expression cohorts of breast tumor showed that high HDAC2 and survivin, and low miR-125a-5p, expression levels correlate with poor relapse-free survival in endocrine therapy and tamoxifen-treated ER⁺ breast cancer patients. Further molecular analysis revealed that HDAC2 and HDAC5 positively modulates the expression of survivin, and negatively regulates the expression miR-125a-5p, in ER⁺ MCF7, MCF7-TamC3, and ZR-75-1 breast cancer cells. These findings indicate that dysregulations of HDAC2 and HDAC5 promote the development of hormone independency and tamoxifen resistance in ERC breast cancer cells in part through expression regulation of survivin and miR-125a-5p.

Danshen improves survival of patients with colon cancer and dihydroisotanshinone I inhibit the proliferation of colon cancer cells via apoptosis and skp2 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Danshen (Salvia miltiorrhiza Bunge) is widely used in traditional Chinese medicine. However, it's definite clinical effect and mechanism on colon carcinoma is unclear.

AIM OF THE STUDY

To test the hypothesis that the protective effect of danshen on colon cancer and discover the bioactive compounds through in vitro study.

MATERIALS AND METHODS

We conducted a nationwide cohort study by using population-based data from the Taiwan National Health Insurance Research Database (NHIRD). The study cohort comprised patients diagnosed with malignant neoplasm of colon (ICD-9-CM codes:153) in catastrophic illness database between January 1, 2000, and December 31, 2010. We used the Kaplan-Meier method to estimate colon [corrected] cancer cumulative incidences. Next, human colon cancer cells (HCT 116 cells and HT29 cells) were used to investigate the effect of dihydroisotanshinone I (DT) on the proliferation and apoptosis of human colon cancer cells and the underlying mechanism through XTT assay and flow cytometry. The in vivo effect of DT treatment was investigated through a xenograft nude mouse model.

RESULTS

In our study, the in vivo protective effect of danshen in the different stage of colon cancer patients was validated through data from the National Health Insurance Research Database in Taiwan. In vitro, we found that dihydroisotanshinone I (DT), a bioactive compound present in danshen, can inhibit the proliferation of colon carcinoma cells, HCT 116 cells and HT-29 cells. Moreover, DT induced apoptosis of colorectal cancer cells. DT also repressed the protein expression of Skp2 (S-Phase Kinase Associated Protein 2) and the mRNA levels of its related gene, Snail1 (Zinc finger protein SNAI1) and RhoA (Ras homolog gene family, member A). In addition, DT also blocked the colon cancer cells recruitment ability of macrophage by decreasing CCL2 secretion in macrophages. DT treatment also significantly inhibited the final tumor volume in a xenograft nude mouse model.

CONCLUSION

Danshen has protective effects in colon cancer patients, which could be attributed to DT through blocking the proliferation of colon cancer cells through apoptosis.

Anti-cancer effect of danshen and dihydroisotanshinone I on prostate cancer: targeting the crosstalk between macrophages and cancer cells via inhibition of the STAT3/CCL2 signaling pathway

Danshen (Salvia miltiorrhiza Bunge) is widely used in traditional Chinese medicine. In our study, the in vivo protective effect of danshen in prostate cancer patients was validated through data from the National Health Insurance Research Database in Taiwan. In vitro, we discovered that dihydroisotanshinone I (DT), a bioactive compound present in danshen, can inhibit the migration of both androgen-dependent and androgen-independent prostate cancer cells. In addition, we noted that DT substantially inhibited the migratory ability of prostate cancer cells in both a macrophage-conditioned medium and macrophage/prostate cancer coculture medium. Mechanistically, DT both diminished the ability of prostate cancer cells to recruit macrophages and reduced the secretion of chemokine (C-C motif) ligand 2 (CCL2) from both macrophages and prostate cancer cells in a dose-dependent manner. Moreover, DT inhibited the protein expression of p-STAT3 and decreased the translocation of STAT3 into nuclear chromatin. DT also suppressed the expression of tumor epithelial-mesenchymal transition genes, including RhoA and SNAI1. In conclusion, danshen can prolong the survival rate of prostate cancer patients in Taiwan. Furthermore, DT can inhibit the migration of prostate cancer cells by interrupting the crosstalk between prostate cancer cells and macrophages via the inhibition of the CCL2/STAT3 axis. These results may provide the basis for a new therapeutic approach toward the treatment of prostate cancer progression.

Role of Sex Hormones in the Development and Progression of Hepatitis B Virus-Associated Hepatocellular Carcinoma

Infection with hepatitis B virus (HBV) is a major risk factor for hepatocellular carcinoma (HCC) in developed countries. Epidemiological reports indicate that the incidence of HBV-related HCC is higher in males and postmenopausal females than other females. Increasing evidence suggests that sex hormones such as androgens and estrogens play an important role in the progression of an HBV infection and in the development of HBV-related HCC. While androgen is supposed to stimulate the androgen signaling pathway and cooperate to the increased transcription and replication of HBV genes, estrogen may play a protecting role against the progression of HBV infections and in the development of HBV-related HCC through decreasing HBV RNA transcription and inflammatory cytokines levels. Additionally, sex hormones can also affect HBV-related hepatocarcinogenesis by inducing epigenetic changes such as the regulation of mRNA levels by microRNAs (miRNAs), DNA methylation, and histone modification in liver tissue. This review describes the molecular mechanisms underlying the gender disparity in HBV-related HCC with the aim of improving the understanding of key factors underneath the sex disparity often observed in HBV infections. Furthermore, the review will propose more effective prevention strategies and treatments of HBV-derived diseases.

Cytotoxicity effect of degraded and undegraded kappa and iota carrageenan in human intestine and liver cell lines

Background

Carrageenan is a linear sulphated polysaccharide extracted from red seaweed of the Rhodophyceae family. It has broad spectrum of applications in biomedical and biopharmaceutical field. In this study, we determined the cytotoxicity of degraded and undegraded carrageenan in human intestine (Caco-2; cancer and FHs 74 Int; normal) and liver (HepG2; cancer and Fa2N-4; normal) cell lines.

Methods

Food grade k-carrageenan (FGKC), dried sheet k-carrageenan (DKC), commercial grade k-carrageenan (CGKC), food grade i-carrageenan (FGIC) and commercial grade i-carrageenan (CGIC) were dissolved in hydrochloric acid and water to prepare degraded and undegraded carrageenan, respectively. Carrageenan at the concentration range of 62.5 – 2000.0 μg mL⁻¹ was used in the study. MTT assay was used to determine the cell viability while the mode of cell death was determined by May-Grunwald Giemsa (MGG) staining, acridine orange-ethidium bromide (AO/EtBr) staining, agarose gel electrophoresis and gene expression analysis.

Results

Degraded FGKC, DKC and CGKC showed IC₅₀ in 24, 48 and 72 hours treated Caco-2, FHs 74 Int, HepG2 and Fa2N-4 cell lines as tested by MTT assay. Degraded FGIC and CGIC only showed its toxicity in Fa2N-4 cells. The characteristics of apoptosis were demonstrated in degraded k-carrageenan treated Caco-2, FHs 74 Int, HepG2 and Fa2N-4 cells after MGG staining. When Caco-2 and HepG2 cells were undergone AO/EtBr staining, chromatin condensation and nuclear fragmentation were clearly seen under the microscope. However, DNA ladder was only found in HepG2 cells after gel electrophoresis analysis. Degraded k-carrageenan also inactivated PCNA, Ki-67 and survivin gene in HepG2. On the other hand, undegraded FGKC, DKC, CGKC, FGIC and CGIC treated cells showed no cytotoxic effect after analyzed by the same analyses as in degraded carrageenan.

Conclusion

Degraded k-carrageenan inhibited cell proliferation in Caco-2, FHs 74 Int, HepG2 and Fa2N-4 cell lines and the anti-proliferative effect was related to apoptosis together with inactivation of cell proliferating genes as determined by morphological observation and molecular analysis. However, no cytotoxic effect was found in undegraded carrageenan towards normal and cancer intestine and liver cell lines.

Chemotherapeutic agents for the treatment of hepatocellular carcinoma: efficacy and mode of action

Hepatocellular carcinoma (HCC) is a dreaded malignancy that every year causes half a million deaths worldwide. Being an aggressive cancer, its incidence exceeds 700,000 new cases per year worldwide with a median survival of 6-8 months. Despite advances in prognosis and early detection, effective HCC chemoprevention or treatment strategies are still lacking, therefore its dismal survival rate remains largely unchanged. This review will characterize currently available chemotherapeutic drugs used in the treatment of HCC. The respective mode(s) of action, side effects and recommendations will be also described for each drug.

Clinicopathological significance of PI3K, Akt and survivin expression in gastric cancer

BACKGROUND

Gastric cancer is the second leading cause of cancer-related deaths worldwide, and is characterized by invasion and metastasis. Increasing attention is being focused on discovering molecular markers for diagnosis and prognosis. Our objective was to evaluate PI3K, Akt and survivin protein expression in gastric cancer, and their correlations with clinicohistological features and prognosis in patients with gastric cancer.

METHODS

Tissue samples were obtained from 70 patients with gastric cancer patients and 20 patients with normal gastric mucosa. The protein levels of PI3K, Akt and survivin were evaluated by immunohistochemistry. Statistical analyses were performed to establish the correlations between their expressions and patients' clinicopathologic characteristics.

RESULTS

The positive expression rates of PI3K, Akt and survivin were significantly higher in the gastric cancer tissues compared to normal gastric mucosa (P<0.05). Expression levels of PI3K, Akt and survivin proteins were significantly correlated with TNM stage, differentiation grade, lymph node metastasis and metastases to other organs (P<0.05). Cooperative relationships were identified between PI3K and Akt, and PI3K and survivin (P<0.01), suggesting the involvement of the PI3K/Akt/survivin signaling pathway in the tumorigenesis of gastric cancer.

CONCLUSIONS

Protein expression of PI3K, Akt and survivin were significantly associated with the development, progression and metastasis of gastric cancer and may have value as diagnostic and prognostic markers in gastric cancer.

The Inhibitory Effect of 3 β -Hydroxy-12-oleanen-27-oic Acid on Growth and Motility of Human Hepatoma HepG2 Cells through JNK and Akt Signaling Pathway

3 β -Hydroxy-12-oleanen-27-oic acid (ATA) was a main antitumor active triterpene from the rhizomes of Astilbe chinensis. In this study, we investigated its effects on growth, apoptosis, cell cycle, motility/invasion, and metatasis in human hepatoma HepG2 cells in vitro and antimetastasis of B16-F10 melanoma in mice in vivo, as well as its molecular mechanisms of action using a high-throughput Cancer Pathway Finder PCR Array. ATA could not only induce tumor cells into apoptosis through the activation of both extrinsic and intrinsic pathways, arrest HepG2 cells in G2/M phase, but also suppress the invasion and metastasis abilities of HepG2 cells and the lung metastasis of B16-F10 melanoma in mice. PCR array assay revealed that ATA upregulated 9 genes including CDKN1A, MDM2, CFLAR (CASPER), TNFRSF10B (DR5), c-Jun, IL-8, THBS1, SERPINB5 (maspin), and TNF and downregulated 8 genes such as CCNE1, AKT, ANGPT1, TEK, TGFBR1, MMP9, U-PA, and S100A4. These results indicate that ATA could exert antitumor effects through activating JNK/MAPK and suppressing AKT signal transduction pathways and that ATA might be a potent anticancer agent.

Progesterone and related compounds in hepatocellular carcinoma: basic and clinical aspects

Primary liver cancer is the fifth most common cancer worldwide and the third most common cause of cancer mortality. Hepatocellular carcinoma (HCC) accounts for 85% to 90% of primary liver cancers. Major risk factors for HCC include infection with HBV or HCV, alcoholic liver disease, and most probably nonalcoholic fatty liver disease. In general, men are two to four times more often associated with HCC than women. It can be suggested that sex hormones including progesterone may play some roles in HCC. Rather, very limited information discusses its potential involvement in HCC. This paper thus collects some recent studies of the potential involvement of progesterone and related compounds in HCC from basic and clinical aspects. In addition, two synthetic progestins, megestrol acetate (MA) and medroxyprogesterone acetate (MPA), will be discussed thoroughly. It is noted that progesterone can also serve as the precursor for androgens and estrogens produced by the gonadal and adrenal cortical tissues, while men have a higher incidence of HCC than women might be due to the stimulatory effects of androgen and the protective effects of estrogen. Eventually, this paper suggests a new insight on the associations of progesterone and related compounds with HCC development and treatment.

Beclin 1-mediated autophagy in hepatocellular carcinoma cells: implication in anticancer efficiency of oroxylin A via inhibition of mTOR signaling

Autophagy is a tightly-regulated catabolic process that involves the degradation of intracellular components via lysosomes. Although the pivotal role of autophagy in cell growth, development, and homeostasis has been well understood, its function in cancer prevention and intervention remains to be delineated. The aim of this study was to investigate the function and mechanism of autophagy induced by oroxylin A, a natural mono-flavonoid extracted from Scutellariae radix. We found for the first time that oroxylin A induced Beclin 1-mediated autophagy in human hepatocellular carcinoma HepG2 cells. Time-lapse video microscopy and western blotting studies showed that treatment of cells with 80 μM oroxylin A resulted in the conversion of water soluble MAP-LC3 (LC3-I) to the lipidated and autophagosome-associated form (LC3-II) after 12hours; then autophagosome-lysosome fusion and lysosome degradation after 24 hours was required in oroxylin A-mediated cell death. This induction was associated with the suppressing of PI3K-PTEN-Akt-mTOR signaling pathway by oroxylin A. Our results also showed that autophagy took place before noticeable apoptosis can be observed. It was further demonstrated that oroxylin A-triggered autophagy contributed to cell death using over-expression of autophagy-related gene (Atg5 and Atg7) and inhibition of autophagy by siBeclin 1 and 3-methyladenine (3-MA). In vivo study, oroxylin A inhibited xenograft tumor growth and induced obvious autophagy in tumors. Taken together, we conclude that oroxylin A exhibits autophagy-mediated antitumor activity in a dose and time-dependent manner in vivo and in vitro. These findings define and support a novel function of autophagy in promoting death of hepatocellular carcinoma cells.

Effects of electroacupuncture on the expression of p70 ribosomal protein S6 kinase and ribosomal protein S6 in the hippocampus of rats with vascular dementia

This study investigated the mechanism underlying electroacupuncture therapy for vascular dementia through electroacupuncture at the acupoints of Baihui (DU20), Dazhui (DU14), and bilateral Shenshu (BL23) in a rat model of vascular dementia produced by bilateral middle cerebral artery occlusion. Morris water maze test showed that electroacupuncture improved the learning ability of vascular dementia rats. Western blot assay revealed that the expression of p70 ribosomal protein S6 kinase and ribosomal protein S6 in vascular dementia rats was significantly increased after electroacupuncture, compared with the model group that was not treated with acupuncture. The average escape latency was also shortened after electroacupuncture, and escape strategies in the spatial probe test improved from edge and random searches, to linear and trending swim pathways. The experimental findings indicate that electroacupuncture improves learning and memory ability by up-regulating expression of p70 ribosomal protein S6 kinase and ribosomal protein S6 in the hippocampus of vascular dementia rats.

β-Elemene induces apoptosis as well as protective autophagy in human non-small-cell lung cancer A549 cells

OBJECTIVES

β-Elemene, a novel traditional Chinese medicine, has been shown to be effective against a wide range of tumours. In this study, the antitumour effect of β-elemene on human non-small-cell lung cancer (NSCLC) A549 cells and the mechanism involved have been investigated.

METHODS

Cell viability and apoptosis were measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. Protein expression was assayed by Western blotting. Autophagy was evaluated under fluorescence microscopy and transmission electron microscopy.

KEY FINDINGS

β-Elemene inhibited the viability of A549 cells in a dose-dependent manner. This suppression of cell viability was due to the induction of apoptosis. Further study showed that β-elemene inhibited the activity of the PI3K/Akt/mTOR/p70S6K1 signalling pathway, and at the same time it triggered a robust autophagy. The autophagy was characterized by the accumulation of punctate LC3 dots in the cytoplasm, morphological changes, and the increased levels of LC3-II as well as Atg5-Atg12 conjugated proteins. Inhibition of autophagy with chlorochine significantly enhanced the antitumour effect of β-elemene.

CONCLUSIONS

Our data indicated that β-elemene inhibited the activity of the PI3K/Akt/mTOR/p70S6K1 signalling pathway in human NSCLC A549 cells, which resulted in apoptosis as well as protective autophagy. A combination of β-elemene with autophagy inhibitor might be an effective therapeutic option for advanced NSCLC.

Decreased immunoexpression of survivin could be a potential marker in human non-alcoholic fatty liver disease progression?

BACKGROUND/AIM

Regulation of apoptosis in non-alcoholic fatty liver disease (NAFLD) has been a theme of growing debate. Although no other study assessed the role of survivin in NAFLD, its expression has been reported in hepatic carcinogenesis because of other aetiological factors with relevant discrepancies. The aim of this study was to assess the pattern of survivin immunoexpression by tissue microarray along the whole spectrum of NAFLD, including non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (HCC).

METHODS

Liver biopsies from 56 patients with NAFLD were evaluated: 18 with steatosis, 21 non-cirrhotic NASH, 10 NASH-related cirrhosis, seven NASH-related HCC, as compared with 71 HCC related to other causes and with 12 normal livers.

RESULTS

Survivin immunoexpression in NAFLD was restricted to cytoplasm and was found to be progressively lower in advanced stages, including cirrhosis and HCC: steatosis vs NASH-related cirrhosis (P=0.0243); steatosis vs NASH-related HCC (P=0.0010); NASH vs NASH-related cirrhosis (P=0.0318); and NASH vs NASH-related HCC (P=0.0007), thus suggesting a deregulation of apoptosis from NAFLD towards HCC. Interestingly, survivin immunoreactivity in NASH-related HCC was also found to be significantly lower than in HCC related to other causes (P<0.05). Remarkably, nuclear staining for survivin was not detected in any case of NAFLD, contrasting to its presence in all other cases of HCC.

CONCLUSIONS

Survivin immunoexpression in NASH-related HCC is herein originally found substantially different than in HCC related to other causes, thus requiring further studies to elucidate the role of survivin in human NAFLD progression.

Survival benefit with proapoptotic molecular and pathologic responses from dual targeting of mammalian target of rapamycin and epidermal growth factor receptor in a preclinical model of pancreatic neuroendocrine carcinogenesis

PURPOSE

Pancreatic neuroendocrine tumors (PNETs), although rare, often metastasize, such that surgery, the only potentially curative therapy, is not possible. There is no effective systemic therapy for patients with advanced PNETs. Therefore, new strategies are needed. Toward that end, we investigated the potential benefit of dual therapeutic targeting of the epidermal growth factor receptor (EGFR) and mammalian target of rapamycin (mTOR) kinases, using a preclinical mouse model of PNET.

MATERIALS AND METHODS

Rapamycin and erlotinib, inhibitors of mTOR and EGFR, respectively, were used to treat RIP-Tag2 transgenic mice bearing advanced multifocal PNET. Tumor growth and survival were monitored, and tumors were surveyed for potential biomarkers of response to the therapeutics.

RESULTS

Rapamycin monotherapy was notably efficacious, prolonging survival concomitant with tumor stasis (stable disease). However, the tumors developed resistance, as evidenced by eventual relapse to progressive tumor growth. Erlotinib monotherapy slowed tumor growth and elicited a marginal survival benefit. In combination, there was an unprecedented survival benefit in the face of this aggressive multifocal cancer and, in contrast to either monotherapy, the development of adaptive resistance was not apparent. Additionally, the antiapoptotic protein survivin was implicated as a biomarker of sensitivity and beneficial responses to the dual targeted therapy.

CONCLUSION

Preclinical trials in a mouse model of endogenous PNET suggest that combined targeting of the mTOR and EGFR signaling pathways could have potential clinical benefit in treating PNET. These results have encouraged development of an ongoing phase II clinical trial aimed to evaluate the efficacy of this treatment regimen in human neuroendocrine tumors.