A Mitochondrion-Targeting Protein (B2) Primes ROS/Nrf2-Mediated Stress Signals, Triggering Apoptosis and Necroptosis in Lung Cancer.

The betanodavirus B2 protein targets mitochondria and triggers mitochondrion-mediated cell death signaling in lung cancer cells; however, its molecular mechanism remains unknown. In this study, we observed that B2 triggers hydrogen peroxide/Nrf2-involved stress signals in the dynamic regulation of non-small lung cancer cell (NSCLC)-programmed cell death. Here, the B2 protein works as a necrotic inducer that triggers lung cancer death via p53 upregulation and RIP3 expression, suggesting a new perspective on lung cancer therapy. We employed the B2 protein to target A549 lung cancer cells and solid tumors in NOD/SCID mice. Tumors were collected and processed for the hematoxylin and eosin staining of tissue and cell sections, and their sera were used for blood biochemistry analysis. We observed that B2 killed an A549 cell-induced solid tumor in NOD/SCID mice; however, the mutant ΔB2 did not. In NOD/SCID mice, B2 (but not ΔB2) induced both p53/Bax-mediated apoptosis and RIPK3-mediated necroptosis. Finally, immunochemistry analysis showed hydrogen peroxide /p38/Nrf2 stress strongly inhibited the production of tumor markers CD133, Thy1, and napsin, which correlate with migration and invasion in cancer cells. This B2-triggered, ROS/Nrf2-mediated stress signal triggered multiple signals via pathways that killed A549 lung cancer tumor cells in vivo. Our results provide novel insight into lung cancer management and drug therapy.

Gastroprotective Effect of Anisomeles indica on Aspirin-Induced Gastric Ulcer in Mice.

Gastric ulcers are commonly seen in the upper gastrointestinal tract and may be related to the Helicobacter pylori infection and the use of aspirin, a nonsteroidal anti-inflammatory drug (NSAID). Typically, proton-pump inhibitors (PPIs) are used to treat gastric ulcers; however, adverse effects have emerged following long-term treatment. Natural medicines are used as alternative therapeutic agents in the treatment of gastric ulcers, with few side effects. Despite various reports on the anti-H. pylori and anti-gastric cancer activities of Anisomeles indica, its gastroprotective effect on ulcers remains undetermined. This study investigated the protective effect of A. indica on aspirin-induced gastric ulcers in murine models. Our results show that three fractions of ethanol-extracted A. indica inhibited aspirin-induced gastric injury. Among these, A. indica Fraction 1 was observed to enrich ovatodiolide, which effectively diminished gastric acidity and alleviated aspirin-induced inflammation in the stomach. Our results provide evidence that A. indica could be developed as an effective therapeutic agent for gastroprotective purposes.

Organic cation transporter 2 activation enhances sensitivity to oxaliplatin in human pancreatic ductal adenocarcinoma.

Oxaliplatin, a third-generation platinum derivative, has become one of the main chemotherapeutic treatments for esophagus, gastric and colorectal cancer; however, it is still unclear the potential effectiveness for pancreatic ductal adenocarcinoma (PDAC) with gemcitabine resistance. Here, we observed that PDAC tumors have low level of organic cation transporter 2 (OCT2, also known as SLC22A2) compared with non-tumor tissues and identified that OCT2 expression is positively correlated with oxaliplatin sensitivity in PDAC cells. Treatment of OCT2 inhibitors or knockdown of OCT2 expression significantly decreased the sensitivity to oxaliplatin in PANC-1 cells. In addition, bisulfite sequencing polymerase chain reaction analysis revealed that higher methylation frequency represses OCT2 expression in gemcitabine-resistant PANC-1 (PANC-1/GR) cells. Moreover, we found that treatment of DNA methyltransferase (DNMT) inhibitors, decitabine or 5-azacytidine recover OCT2 expression and oxaliplatin sensitivity in PANC-1/GR cells, and DNMT1 level has inverse correlation with OCT2 expression in PDAC cells and tumors. Our findings jointly suggest that OCT2 expression is a potential and predictive marker for evaluating oxaliplatin sensitivity and developing alternative treatments for PDAC patients with gemcitabine resistance.

The analgesic effect of intravenous lidocaine versus intrawound or epidural bupivacaine for postoperative opioid reduction in spine surgery: A systematic review and meta-analysis.

BACKGROUND: Pain management following spine surgery remains a challenge. The significant use of opioids may lead to opioid-related adverse events. These complications can increase perioperative morbidity and rapidly expend health care resources by developing chronic pain. Although intraoperative pain control for surgery has been studied in the literature, a thorough assessment of the effect in spine surgery is rarely reported. The objective of the present study was to examine the outcomes of intraoperative intravenous lidocaine and intrawound or epidural bupivacaine use in spine surgery. METHODS: An electronic literature search was conducted for studies on the use of lidocaine and bupivacaine in spine surgery for all years available. Only articles in English language were included. Postoperative opioid consumption, VAS score, nausea/vomiting, and length of hospital stay comprised the outcomes of interest. Pooled descriptive statistics with Risk Ratios (RR), Mean Differences (MD) and 95 % confidence interval were used to synthesize the outcomes for each medication. RESULTS: A total of 10 studies (n = 579) were included in the analysis. Comparison of the opioid consumption revealed a significant mean difference between lidocaine and bupivacaine (MD: -12.25, and MD: -0.4, respectively, p = 0.01), favoring lidocaine. With regard to postoperative VAS, the pooled effect of both groups decreased postoperative pain (MD: -0.61 (95 % CI: -1.14, -0.08)), with a more significant effect in the lidocaine group (MD: -0.84, (95 % CI: -1.21, -0.48)). There was no significant effect in length of stay, and postoperative nausea/vomiting. CONCLUSIONS: The results of the present meta-analysis indicate that lidocaine and bupivacaine use may decrease postoperative pain and opioid consumption. Lidocaine had a stronger effect on the reduction of opioid consumption compared to bupivacaine.

Toll-like receptor 4 prevents AOM/DSS-induced colitis-associated colorectal cancer in Bacteroides fragilis gnotobiotic mice.

Bacteroides fragilis (BF) plays a critical role in developing and maintaining the mammalian immune system. We previously found that BF colonization could prevent inflammation and tumor formation in a germ-free (GF) colitis-associated colorectal cancer (CAC) mouse model. The role of Toll-like receptor 4 (TLR4) in CAC development has not been clearly elucidated in BF mono-colonized gnotobiotic mice. The wild-type (WT) and TLR4 knockout (T4K) germ-free mice were raised with or without BF colonization for 28 days (GF/WT, GF/T4K, BF/WT, and BF/T4K) and then CAC was induced under azoxymethane (AOM)/dextran sulfate sodium (DSS) administration. The results showed that tumor formation and tumor incidence were significantly inhibited in the BF/WT group compared to those observed in the GF/WT group. However, the tumor prevention effect was not observed in the BF/T4K group unlike in the BF/WT group. Moreover, the CAC histological severity of the BF/WT group was ameliorated, but more severe lesions were found in the GF/WT, GF/T4K, and BF/T4K groups. Immunohistochemistry showed decreased cell proliferation (PCNA, ß-catenin) and inflammatory markers (iNOS) in the BF/WT group compared to those in the BF/T4K group. Taken together, BF mono-colonization of GF mice might prevent CAC via the TLR4 signal pathway.

The novel camptothecin derivative, CPT211, induces cell cycle arrest and apoptosis in models of human breast cancer.

OBJECTIVE: Breast cancer is the second leading cause of cancer deaths in women worldwide and represents a highly aggressive nature with limited therapeutic options; thus, investigating novel therapeutic agents for breast cancer is much needed. In this study, we investigated the anticancer effects of a novel camptothecin derivative, CPT211, against human breast cancer. METHODS: We used hormone receptor-positive MCF-7, triple-negative (TNBC) MDA-MB-231, and HER2-positive BT-474 human breast cancer cells to examine cytotoxicity of CPT211. We measured cell viability with dose dependence of CPT211 treatments by an MTT assay and investigated the potential underlying mechanism through flow cytometric and Western blot methods. Furthermore, we evaluated the efficacy of the treatment combination of CPT211 and doxorubicin in a mouse model bearing MDA-MB-231 xenografts. RESULTS: CPT211 treatment led to dose-dependent decreases in cell viability of both MCF-7 and MDA-MB-231 cells, but not BT-474 cells. Analysis of the underlying molecular mechanism revealed that CPT211 activated p53-mediated apoptosis, by triggering intrinsic and extrinsic apoptotic pathways in MCF-7 cells. Additionally, CPT211 induced apoptosis and cell cycle arrest of MDA-MB-231 cells by activating Fas/FADD/caspase-8 signaling, suggesting that CPT211-mediated MDA-MB-231 cell apoptosis may occur through an extrinsic apoptosis pathway. CPT211 treatment with doxorubicin in mice bearing MDA-MB-231 xenografts was shown to enhance caspase-8 and caspase-7 activation, resulting in significant inhibition of tumor growth. CONCLUSIONS: These results indicate that Fas/FADD/caspase-8 activation plays an important role in CPT211-mediated tumor growth suppression in TNBC, and the novel camptothecin derivative, CPT211, can be exploited for specific targeted therapies and potentially improve approaches to combination treatments for human breast cancer.

6,7-Dihydroxy-2-(4'-hydroxyphenyl)naphthalene induces HCT116 cell apoptosis through activation of endoplasmic reticulum stress and the extrinsic apoptotic pathway.

BACKGROUND: Colorectal cancer is the third leading cause of cancer-related deaths worldwide, and therefore, the development of novel drugs for its prevention and therapy are urgently required. This study aimed to determine the molecular mechanism of 6,7-dihydroxy-2-(4'-hydroxyphenyl) naphthalene (PNAP-6)-induced cytotoxicity in human colorectal cancer (HCT116) cells. METHODS: The effects of 2-phenylnaphthalene derivatives on HCT116 cell growth and viability were assessed by MTT assays. The mechanisms involved in the regulation of the extrinsic apoptosis and endoplasmic reticulum (ER) stress pathways by PNAP-6 were analyzed by annexin-V/propidium iodide flow cytometric analysis, Hoechst 33342 fluorescent staining, and Western blotting. RESULTS: PNAP-6 was shown to have an IC50 value 15.20 µM. It induced G2/M phase arrest in HCT116 cells, associated with a marked decrease in cyclin B and CDK1 protein expression and increased caspase activation, PARP cleavage, chromatin condensation, and sub-G1 apoptosis. Moreover, we found that the apoptotic effects of PNAP-6 proceeded through extrinsic apoptosis and ER stress pathways, by increasing the expression of Fas protein and ER stress markers, including PERK, ATF4, CHOP, p-IRE1α, and XBP-1s. CONCLUSION: These results suggest that 2-phenylnaphthalene derivatives, such as PNAP-6, have potential as new treatments for colorectal cancer.

The germ-free mice monocolonization with Bacteroides fragilis improves azoxymethane/dextran sulfate sodium induced colitis-associated colorectal cancer.

Objective: Inflammatory bowel disease (IBD) is generally considered as a major risk factor in the progression of colitis-associated colorectal cancer (CAC). Previous studies have indicated that the composition of gut microflora may be involved in CAC induction and progress. Bacteroides fragilis (BF) is a Gram-negative anaerobe belonging to colonic symbiotic bacteria of the host. This study was aimed to investigate the protective role of BF in a colorectal cancer (CRC) model induced by azoxymethane (AOM) and dextran sulfate sodium (DSS) in germ-free (GF) mice. Materials and methods: Total 22 GF mice were divided into two groups: GF and BF group. Half of the GF mice were colonized with BF for 28 days before CRC induction by AOM/DSS. Results: BF colonization increased animal survival (100%). Cecum weight and cecum/body weight ratio significantly decreased in BF/AOM/DSS group. Interestingly, there was a significant decrease in tumor number and tumor incidence in the BF/AOM/DSS group as compared to the GF/AOM/DSS group. The adenocarcinoma/adenoma incidence and histologic score were also decreased in the BF/AOM/DSS group. In addition, immunohistochemistry staining found decreased numbers of cell proliferation (PCNA) and inflammatory cell (granulocytes) infiltration in the colon mucosa of the BF group. The ß-catenin staining in the BF/AOM/DSS group had fewer and weaker positive signal expressions. Taking together, the BF colonization significantly ameliorated AOM/DSS-induced CRC by suppressing the activity of cell proliferation-related molecules and reducing the number of inflammatory cells. Conclusions: Symbiotic BF may play a pivotal role in maintaining the gastrointestinal immunophysiologic balance and regulating anti-tumorigenesis responses.

Effects of plant- and animal-based high-fat diets on lipid storage and distribution in environmental bacteria-colonized gnotobiotic mice.

Different edible oils such as lard and soybean oil have been reported to interact with the gut microbiota, affecting host lipid metabolism. However, whether bacteria derived from the environment influence host lipid metabolism remains unclear. This study aimed to clarify the roles of environmental bacteria in host lipid storage and distribution with various edible oils. Gnotobiotic C57BL/6JNarl mice were inoculated with Lysinibacillus xylanilyticus and Paenibacillus azoreducens and then fed either a normal diet (LabDiet 5010, control group) or a diet containing 60% lard (L-group) or soybean oil (S-group) for 18 months. Interestingly, the S-group accumulated massive amounts of white adipose tissue compared to the L- and control groups, while the L-group displayed more hepatic steatosis and fatty droplets than the other groups. The expression of fatty acid synthase (FAS), hydroxymethylglutaryl-coenzyme A reductase (HMGCR), sterol regulatory element-binding protein 2 (SREBP2), and peroxisome proliferator-activated receptor gamma (PPARγ) in the livers of the L-group were markedly elevated compared to the S-group. FAS and PPARγ protein levels were also markedly elevated. However, there were no differences in the expression of the pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-α between the groups. Our results suggest that environmental bacteria may affect host hepatic inflammation and lipid distribution in the presence of high-fat diets, with different effects depending on the fat type consumed.

TLR2 and interleukin-10 are involved in Bacteroides fragilis-mediated prevention of DSS-induced colitis in gnotobiotic mice.

BACKGROUND AND AIMS: Bacteroides fragilis (BF) are Gram-negative anaerobe symbionts present in the colon. Recent studies have reported the beneficial role of BF in maintaining intestinal homeostasis, stimulating host immunologic development, and preventing infectious colitis caused by pathogenic bacteria. Our previous studies showed that monocolonization of germ-free mice with BF significantly reduced colon inflammations and damage. METHODS: In order to investigate the Toll-like receptor-2 (TLR2), TLR4, and interleukin 10 (IL-10) molecular signaling pathways involved in BF-mediated prevention of dextran sulfate sodium (DSS)-induced colitis. The wild-type (WT), TLR4, TLR2, and IL-10 knockout (-/-) germ-free mice grown were with or without BF colonization for 28 days, and then administered 1% DSS in drinking water for 7 day to induce acute ulcerative colitis. RESULTS: We compared phenotypes such as weight loss, disease activity, intestinal histological scores, and immunohistochemistry for inflammatory cells. Unlike WT and TLR4-/- mice, the severity of DSS-colitis did not improve in TLR2-/- animals after BF colonization. The BF enhanced anti-inflammatory cytokines IL-10 expression and inhibited pro-inflammatory-related tumor necrosis factor (TNF-α) and IL-6 mRNA expression in both WT and TLR4-/- mice. In contrast, the failed to up-regulated IL-10 and down-regulated the TNF-α and IL-6 in BF colonization TLR2-/- mice. In addition, we further perform IL-10-/- mice to clarify whether the BF through TLR2 /IL-10 pathway to alleviate DSS-colitis. There were no significant differences in colitis severity and pro-inflammatory related genes expression in the IL-10-/- mice with or without BF colonization. CONCLUSIONS: These results indicate the disease-preventing effects of BF in acute DSS-induced colitis may occur through the TLR2/IL-10 signal pathway.

Combined Treatment with Hyaluronic Acid and Mesalamine Protects Rats from Inflammatory Bowel Disease Induced by Intracolonic Administration of Trinitrobenzenesulfonic Acid.

Drugs such as mesalamine (5-ASA) are currently recommended for the treatment of inflammatory bowel disease (IBD). To reduce the frequency of their administration and improve their therapeutic effect, this study investigated the adhesion efficacy, wound healing promotion, and decrease in inflammation in ulcers in the colonic tissue of rats with colitis after combined treatment with hyaluronic acid (HA) and 5-ASA (IBD98-M). HA-fluoresceinamine (FL) conjugates successfully adhered to the mucosal layer and were conjugated in the vascular tissue. In addition, macroscopic and microscopic observations indicated that colonic injuries reduced significantly after treatment with IBD98-M. Compared with PBS and 5-ASA treatment alone, treatment with IBD98-M more effectively reduced bowel inflammation and promoted colonic mucosal healing in TNBS-induced colitis. IBD98-M treatment also reduced myeloperoxidase activity and the expression levels of cyclooxygenase 2 and tumor necrosis factor-αin the colitis tissue. In conclusion, IBD98-M treatment strongly promoted wound healing in colonic injuries and significantly inhibited MPO activity in the inflamed colon tissue of rats. Combined treatment with HA and 5-ASA can accelerate wound healing and reduce inflammatory reaction in rat colitis.

Soluble epoxide hydrolase activity regulates inflammatory responses and seizure generation in two mouse models of temporal lobe epilepsy.

Neuroinflammation is known to be involved in epileptogenesis with unclear mechanisms. Inhibition of soluble epoxide hydrolase (sEH) seems to offer anti-inflammatory protection to ischemic brain injury in rodents. Thus, it is hypothesized that sEH inhibition might also affect the neuroinflammatory responses caused by epileptic seizures. In the present study, we investigated the involvement of sEH in neuroinflammation, seizure generation and subsequent epileptogenesis using two mouse models of temporal lobe epilepsy. Experimental epileptic seizures were induced by either pilocarpine or electrical amygdala kindling in both wild-type (WT) C57BL/6 mice and sEH knockout (sEH KO) mice. The sEH expression in the hippocampus was detected by immunohistochemistry and Western blot analysis. The effects of the sEH hydrolase inhibitors, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) and N-[1-(1-oxopropyl)-4-piperidinyl]-N'-[4-(trifluoromethoxy) phenyl)-urea (TPPU), and of the genetic deletion of sEH on seizure-induced neuroinflammatory responses and the development of epilepsy were evaluated. In the hippocampus of WT mice, sEH was mainly expressed in astrocytes (GFAP(+)), neurons (NeuN(+)) and scattered microglia (Iba-1(+)) in the regions of CA1, CA3 and dentate gyrus. Expression of sEH was significantly increased on day 7, 14, 21 and 28 after pilocarpine-induced status epilepticus (SE). Administration with sEH inhibitors attenuated the SE-induced up-regulation of interleukin-1ß (IL-1ß) and interleukin-6 (IL-6), the degradation of EETs, as well as IκB phosphorylation. Following treatment with AUDA, the frequency and duration of spontaneous motor seizures in the pilocarpine-SE mice were decreased and the seizure-induction threshold of the fully kindled mice was increased. Up-regulation of hippocampal IL-1ß and IL-6 was found in both WT and sEH KO mice after successful induction of SE. Notably, sEH KO mice were more susceptible to seizures than WT mice. Seizure related neuroinflammation and ictogenesis were attenuated by pharmacological inhibition of sEH enzymatic activity but not by sEH genetic deletion. Therefore, sEH may play an important role in the generation of epilepsy. Furthermore, the effectiveness of AUDA in terms of anti-inflammatory and anti-ictogenesis properties suggests that it may have clinical therapeutic implication for epilepsy in the future, particularly when treating temporal lobe epilepsy.

Recombinant viral capsid protein VP1 suppresses lung cancer metastasis by inhibiting COX-2/PGE2 and MIG-7.

Recombinant capsid protein VP1 (rVP1) of foot-and-mouth disease virus binds to integrins to modulate Akt/GSK3-ß signaling and suppress migration/invasion and metastasis of cancer cells, but the underlying molecular mechanism is unclear. Here, we showed that the rVP1-mediated inhibition of Akt/GSK3-ß signaling and cell migration/invasion was accompanied by downregulation in phosphatidylinositol (3,4,5)-triphosphate (PIP3), integrin-linked kinase (ILK) and IKK/NF-κB signaling as well as suppression of COX-2/PGE2 and MIG-7. Addition of PIP3 or overexpression of ILK reversed the rVP1-induced inhibition of IKK/NF-κB signaling, COX-2 and MIG-7. The rVP1-mediated downregulation of COX-2/PGE2 and MIG-7 led to not only attenuation of epithelial-mesenchymal transition, MMP2 activity and invasion of lung cancer cells in vitro but also decreased tumor growth and metastasis of lung cancer in xenograft mice. Moreover, downregulation of COX-2/PGE2 and MIG-7 significantly prolonged the overall and disease-free survival of lung cancer-bearing mice. These results suggest that rVP1 inhibits cancer invasion/metastasis, partly if not mainly, via downregulating integrin/PI3K/Akt, ILK and IKK/NF-κB signaling to suppress expression of COX-2/PGE2 and MIG-7.

MIG-7 controls COX-2/PGE2-mediated lung cancer metastasis.

More effective treatments for metastatic lung cancer remain a pressing clinical need. In this study, we identified migration inducting gene-7 (MIG-7) protein as critical for COX-2/prostaglandin E2 (PGE2)- and Akt/GSK-3ß-dependent tumor invasion/metastasis. COX-2/PGE2 activated EP4 to enhance Akt and GSK-3ß phosphorylation and ß-catenin/T-cell factor/lymphoid enhancer factor signaling leading to MIG-7 upregulation. RNAi-mediated attenuation of MIG-7 blocked COX-2/PGE2- and Akt/GSK-3ß-mediated migration/invasion effects. Furthermore, MIG-7 protein inhibited protein phosphatase 2A to sustain Akt/GSK-3ß phosphorylation and cancer-cell migration/invasion. Cancer cells overexpressing MIG-7 exhibited increased expression of ZEB-1 and Twist in parallel with epithelial-mesenchymal transition, metastasis and cancer lethality. MIG-7 protein level positively correlated with advanced stages of human lung cancers. MIG-7 thus offers a theranostic target for cancer metastases arising from aberrant activation of the cellular COX-2/PGE2 and Akt/GSK-3ß signaling pathways.

Recombinant viral protein VP1 suppresses HER-2 expression and migration/metastasis of breast cancer.

Breast cancer is one of the most common cancers in women worldwide and metastasis is the major cause of breast cancer death. Development of new therapeutic agents for inhibiting breast cancer metastasis is therefore an urgent need. We previously demonstrated that recombinant DNA-derived viral capsid protein VP1 (rVP1) of foot-and-mouth disease virus-induced apoptosis of MCF-7 breast cancer cells in vitro. Here, we investigated whether rVP1 exhibits any inhibitory effects on migration/metastasis and human epidermal growth factor receptor 2 (HER-2), a well-known biomarker for poor prognosis of breast cancer. The effects of rVP1 on cancer cell migration/invasion and metastasis were evaluated using Transwell migration assay and animal cancer models of metastasis. Western blotting, RT-PCR, flow cytometry, immunohistochemistry, and immunofluorescence staining techniques were used to investigate the effects of rVP1 on HER-2 and signal transduction mediators. Non-cytotoxic concentrations of rVP1-induced mesenchymal-epithelial transition and significantly suppressed AP-2α and HER-2 expression as well as the migration and invasion of a variety of breast cancer cell lines in a ß1-integrin-dependent manner in vitro. Gross and histopathologic examinations showed that rVP1 also suppressed metastasis of several breast cancer cell lines, including HER-2-overexpressing SK-BR-3 and BT-474 cells to lung, liver, or peripheral lymph node in orthotopic allograft/xenograft murine models. In addition, rVP1 significantly prolonged survival in breast cancer-bearing mice. Notably, no apparent side effects of rVP1 were detected, as shown by normal complete blood count levels and serum biochemistry profiles, including AST, ALT, BUN, and creatine. This study demonstrates that rVP1 suppresses the migration, invasion, and metastasis of breast cancer cells via binding to ß1 integrin receptor and down-regulation of AP-2α and HER-2 expression. The effectiveness of rVP1 on inhibiting migration/metastasis of breast cancer and HER-2 expression suggests that it may be suitable for serving as potential therapeutics for metastatic breast cancer particularly HER-2-overexpressing cancer.

Recombinant viral capsid protein VP1 suppresses migration and invasion of human cervical cancer by modulating phosphorylated prohibitin in lipid rafts.

Recombinant capsid protein VP1 (rVP1) of foot-and-mouth disease virus inhibits invasion/metastasis of cancer cells. Here we studied its mechanism of action on human cervical cancer cells. The inhibition of cell invasion by rVP1 was accompanied with reduction in phosphatidylinositol (3,4,5)-triphosphate (PIP3), phospho-Akt S473, phosphorylated prohibitin (phospho-PHB) T258 in lipid rafts, dissociation of phospho-PHB T258 with Raf-1 and the inactivation of Raf-1/ERK. Addition of PIP3 or overexpression of constitutively active Akt and raft-anchored PHB T258 but not PHB T258I mutant protein reversed the inhibitory effects of rVP1. rVP1 inhibited cervical tumor growth and metastasis, and prolonged survival in xenograft mouse models. These results suggest that rVP1 inhibits cancer metastasis via de-phosphorylation of Akt and PHB T258 in lipid rafts to downregulate Raf/ERK signaling.

Recombinant viral protein promotes apoptosis and suppresses invasion of ovarian adenocarcinoma cells by targeting α5ß1 integrin to down-regulate Akt and MMP-2.

BACKGROUND AND PURPOSE: As prognosis for patients with metastatic ovarian cancer is generally poor, advances in treatment are needed. Here, we studied the mechanism of action of a recombinant viral capsid protein (rVP1) and explored its effect against ovarian tumour growth and metastasis in vivo. EXPERIMENTAL APPROACH: The human ovarian cancer cell line SKOV3 and BALB/cAnN-Foxn1 female nude mice were used. Effects of rVP1 on the viability, invasive ability, matrix metalloproteinase (MMP)-2 activity and cancer cell proliferation and metastasis were determined by cell proliferation assay, Matrigel invasion assay, gelatin zymographic analysis, as well as bioluminescence imaging and immunohistological analysis in xenograft mouse models respectively. Levels of total and phosphorylated focal adhesion kinase (FAK), PKB/Akt, phosphatase and tensin homologue (PTEN) and glycogen synthase kinase-3ß (GSK-3ß) were detected by Western blotting. KEY RESULTS: rVP1 promoted apoptosis and decreased invasion of human ovarian cancer cells. This effect of rVP1 was accompanied by activation of PTEN and GSK-3ß as well as down-regulation of FAK, Akt and MMP-2. Anti-integrin antibodies or overexpression of constitutively active Akt reversed the cellular effects of rVP1. Orthotopic and intraperitoneal xenograft mouse models demonstrated that rVP1 attenuated survival and metastasis of human ovarian cancer SKOV3 cell line in vivo through selective regulation of Akt and GSK-3ß activity as shown by bioluminescence imaging of mice and immunohistochemical analysis. CONCLUSION AND IMPLICATIONS: These results indicate that negative regulation of Akt signalling and MMP-2 by rVP1 may have the potential to suppress ovarian tumour growth and metastasis in vivo.

Recombinant VP1, an Akt inhibitor, suppresses progression of hepatocellular carcinoma by inducing apoptosis and modulation of CCL2 production.

BACKGROUND: The application of viral elements in tumor therapy is one facet of cancer research. Recombinant capsid protein VP1 (rVP1) of foot-and-mouth disease virus has previously been demonstrated to induce apoptosis in cancer cell lines. Here, we aim to further investigate its apoptotic mechanism and possible anti-metastatic effect in murine models of hepatocellular carcinoma (HCC), one of the most common human cancers worldwide. METHODOLOGY/PRINCIPAL FINDINGS: Treatment with rVP1 inhibited cell proliferation in two murine HCC cell lines, BNL and Hepa1-6, with IC50 values in the range of 0.1-0.2 µM. rVP1 also induced apoptosis in these cells, which was mediated by Akt deactivation and dissociation of Ku70-Bax, and resulted in conformational changes and mitochondrial translocation of Bax, leading to the activation of caspases-9, -3 and -7. Treatment with 0.025 µM rVP1, which did not affect the viability of normal hepatocytes, suppressed cell migration and invasion via attenuating CCL2 production. The production of CCL2 was modulated by Akt-dependent NF-κB activation that was decreased after rVP1 treatment. The in vivo antitumor effects of rVP1 were assessed in both subcutaneous and orthotopic mouse models of HCC in immune-competent BALB/c mice. Intratumoral delivery of rVP1 inhibited subcutaneous tumor growth as a result of increased apoptosis. Intravenous administration of rVP1 in an orthotopic HCC model suppressed tumor growth, inhibited intra-hepatic metastasis, and prolonged survival. Furthermore, a decrease in the serum level of CCL2 was observed in rVP1-treated mice. CONCLUSIONS/SIGNIFICANCE: The data presented herein suggest that, via inhibiting Akt phosphorylation, rVP1 suppresses the growth, migration, and invasion of murine HCC cells by inducing apoptosis and attenuating CCL2 production both in vitro and in vivo. Recombinant protein VP1 thus has the potential to be developed as a new therapeutic agent for HCC.