D-4F, an apoA-I mimetic peptide, inhibits proliferation and tumorigenicity of epithelial ovarian cancer cells by upregulating the antioxidant enzyme MnSOD

Serum high-density lipoprotein level and prognosis of ovarian cancer

This study aimed to investigate the prognostic value of serum high-density lipoprotein (HDL) level in patients with ovarian cancer. This study enrolled 152 patients diagnosed with ovarian cancer and 119 patients with benign ovarian tumors. The associations of patient characteristics and disease with survival were determined using Cox regression analysis, t tests, analysis of variance for multiple-group comparisons, and chi-square tests. The potential association between HDL levels and the clinical characteristics of the disease was also analyzed. The diagnostic value of HDL was estimated using receiver operating characteristic curve analysis and calculation of the area under the curve. Progression-free survival and overall survival were determined using the Kaplan-Meier method, and their associations with patient and pathological variables, including HDL, were determined using the log-rank test. The median serum HDL was 1.15 mm measured in 152 patients with ovarian cancer and 1.30 mm in 119 patients with benign ovarian tumors (P = .000054). The receiver operating characteristic curve analysis yielded an area under the curve of 0.735 for serum HDL levels. Serum HDL levels were significantly associated with tumor pathological types (non-serous vs serous, P < .05). No association was observed between serum HDL levels and patient age, age at menarche or marriage, number of children, tumor grade, or clinical stage (P > .05). Patients with high serum HDL levels had a longer progression-free survival and overall survival than those with low serum HDL levels. Serum HDL levels are an independent prognostic factor for ovarian cancer.

A Phase I-II multicenter trial with Avelumab plus autologous dendritic cell vaccine in pre-treated mismatch repair-proficient (MSS) metastatic colorectal cancer patients; GEMCAD 1602 study

BACKGROUND

Immune check-point blockade (ICB) has shown clinical benefit in mismatch repair-deficient/microsatellite instability high metastatic colorectal cancer (mCRC) but not in mismatch repair-proficient/microsatellite stable patients. Cancer vaccines with autologous dendritic cells (ADC) could be a complementary therapeutic approach to ICB as this combination has the potential to achieve synergistic effects.

METHODS

This was a Phase I/II multicentric study with translational sub-studies, to evaluate the safety, pharmacodynamics and anti-tumor effects of Avelumab plus ADC vaccine in heavily pre-treated MSS mCRC patients. Primary objective was to determine the maximum tolerated dose and the efficacy of the combination. The primary end-point was 40% progression-free survival at 6 months with a 2 Simon Stage.

RESULTS

A total of 28 patients were screened and 19 pts were included. Combined therapy was safe and well tolerated. An interim analysis (Simon design first-stage) recommended early termination because only 2/19 (11%) patients were disease free at 6 months. Median PFS was 3.1 months [2.1-5.3 months] and overall survival was 12.2 months [3.2-23.2 months]. Stimulation of immune system was observed in vitro but not clinically. The evaluation of basal RNA-seq noted significant changes between pre and post-therapy liver biopsies related to lipid metabolism and transport, inflammation and oxidative stress pathways.

CONCLUSIONS

The combination of Avelumab plus ADC vaccine is safe and well tolerated but exhibited modest clinical activity. Our study describes, for the first-time, a de novo post-therapy metabolic rewiring, that could represent novel immunotherapy-induced tumor vulnerabilities.

Apolipoproteins: New players in cancers

Apolipoproteins (APOs), the primary protein moiety of lipoproteins, are known for their crucial role in lipid traffic and metabolism. Despite extensive exploration of APOs in cardiovascular diseases, their roles in cancers did not attract enough attention. Recently, research focusing on the roles of APOs in cancers has flourished. Multiple studies demonstrate the interaction of APOs with classical pathways of tumorigenesis. Besides, the dysregulation of APOs may indicate cancer occurrence and progression, thus serving as potential biomarkers for cancer patients. Herein, we summarize the mechanisms of APOs involved in the development of various cancers, their applications as cancer biomarkers and their genetic polymorphism associated with cancer risk. Additionally, we also discuss the potential anti-cancer therapies by virtue of APOs. The comprehensive review of APOs in cancers may advance the understanding of the roles of APOs in cancers and their potential mechanisms. We hope that it will provide novel clues and new therapeutic strategies for cancers.

The ApoA-I mimetic peptide 4F attenuates in vitro replication of SARS-CoV-2, associated apoptosis, oxidative stress and inflammation in epithelial cells

An oral antiviral against SARS-CoV-2 that also attenuates inflammatory instigators of severe COVID-19 is not available to date. Herein, we show that the apoA-I mimetic peptide 4 F inhibits Spike mediated viral entry and has antiviral activity against SARS-CoV-2 in human lung epithelial Calu3 and Vero-E6 cells. In SARS-CoV-2 infected Calu3 cells, 4 F upregulated inducers of the interferon pathway such as MX-1 and Heme oxygenase 1 (HO-1) and downregulated mitochondrial reactive oxygen species (mito-ROS) and CD147, a host protein that mediates viral entry. 4 F also reduced associated cellular apoptosis and secretion of IL-6 in both SARS-CoV-2 infected Vero-E6 and Calu3 cells. Thus, 4 F attenuates in vitro SARS-CoV-2 replication, associated apoptosis in epithelial cells and secretion of IL-6, a major cytokine related to COVID-19 morbidity. Given established safety of 4 F in humans, clinical studies are warranted to establish 4 F as therapy for COVID-19.

Combined transcriptomic and lipidomic analysis of D-4F ameliorating bleomycin-induced pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease that leads to respiratory failure, and for which there is no effective treatment. Apolipoprotein A-1 (ApoA-1) has been reported to ameliorate the bleomycin (BLM)-induced IPF model.

Methods

To examine the function of D-4F, an ApoA-1 mimetic polypeptide, in IPF, we used an in-vivo BLM-induced model. We assigned mice into the following 3 groups: the Blank Group (BLK Group), the Bleomycin Treatment Group (Model Group), and the D-4F Interference Group (Inter Group). The BLM-induced fibrosis was examined by hematoxylin and eosin, Masson’s trichrome (M-T) staining and immunohistochemical staining. An untargeted lipidomic and transcriptomic analysis were used to examine the function of D-4F.

Results

There were 35 differentially altered lipids (DALs) in the BLK, Model and Inter Groups. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that glycerophospholipid metabolism was the most highly enriched of the 35 DALs. There were 99 differentially expressed genes (DEGs) in the BLK, Model and Inter Groups. The enriched KEGG pathway analysis showed that the mitogen-activated protein kinase (MAPK) pathway was 1 of the top 10 pathways. The results of the untargeted lipidomic and transcriptomic analysis showed that phospholipase A2 group 4c (Pla2g4c) was a crucial gene in both the MAPK pathway and glycerophospholipid metabolism. Pla2g4c was increased in the Model Group but decreased in the Inter Group.

Conclusions

It may be that D-4F prevented the BLM-induced pulmonary fibrosis model by inhibiting the expression of pla2g4c. Our findings suggest that D-4F may be a potential treatment of IPF.

Curcumin loaded sub-30 nm targeting therapeutic lipid nanoparticles for synergistically blocking nasopharyngeal cancer growth and metastasis

Systemic chemotherapy is still the primary treatment for advanced-stage nasopharyngeal carcinoma (NPC), but only limited therapeutic success has been achieved in the past decade because of drug resistance and systemic toxicity. Curcumin (Cur) is an effective alternative to chemotherapeutics because it showed remarkable therapeutic potential in the treatment of NPC. However, lack of tissue specificity and poor penetration in solid tumors are the major obstacles to effective therapy. Therefore, in this work, a self-assembled sub-30 nm therapeutic lipid nanoparticle loaded with Cur, named as Cur@α-NTP-LN, was constructed, specifically targeting scavenger receptor class B member 1 (SR-B1) and enhancing its therapeutic effects on NPC in vivo. Our results showed that Cur@α-NTP-LNs were effective and superior to free Cur on NPC cell-specific targeting, suppressing cell proliferation and inducing cell apoptosis. In vivo and ex vivo optical imaging revealed that Cur@α-NTP-LNs exerted high targeting efficiency, specifically accumulating in NPC xenograft tumors and delivering Cur into the tumor center after systemic administration. Furthermore, Cur@α-NTP-LNs exhibited a remarkable inhibitory effect on the growth of NPC subcutaneous tumors, with over 71 and 47% inhibition compared to Cur- and α-NTP-LNs-treated groups, respectively. In addition, Cur@α-NTP-LNs almost blocked NPC metastasis in a lung metastasis model of NPC and significantly improved the survival rate. Thus, the sub-30 nm Cur@α-NTP-LNs enhanced the solubility of Cur and demonstrated the ability of targeted Cur delivery into the center of the solid NPC tumor, performing synergistic inhibitory effects on the growth of NPC tumor and its metastasis with high efficiency.

TRIM15 promotes the invasion and metastasis of pancreatic cancer cells by mediating APOA1 ubiquitination and degradation

Most pancreatic ductal adenocarcinomas (PDACs) are diagnosed at an advanced or metastatic stage. Metastasis is the one of the major obstacles to prolonging the survival time of patients with pancreatic cancer. The tripartite motif (TRIM) family member TRIM15 has been implicated in cancer development. Our bioinformatics analysis indicated that TRIM15 might be involved in the regulation of pancreatic cancer metastasis. However, the role of TRIM15 in PDAC remains unclear. Metabolic reprogramming involving dysregulated lipid synthesis is common in patients with PDAC. Targeting lipid anabolism has been proposed as a strategy to treat PDAC. In this study, we demonstrated that TRIM15 expression was elevated in PDAC tissues, and this elevated expression was associated with a poor prognosis. TRIM15 silencing suppressed the invasion and migration of pancreatic cancer cells. Importantly, the mass spectrometry analysis suggested that Apolipoprotein A1 (APOA1), the main component of high-density lipoprotein (HDL) that is involved in lipid transport and metabolism, might be one of the binding partners of TRIM15. Further experiment indicated that TRIM15 interacted with APOA1 through its PRY/SPRY domain and promoted APOA1 polyubiquitination via its RING domain. APOA1 degradation enhanced lipid anabolism and promoted lipid droplet accumulation in pancreatic cancer cells. Furthermore, we showed that TRIM15 might promote PDAC metastasis by regulating lipid metabolism via the APOA1-LDLR axis. Consequently, targeting the TRIM15-APOA1-LDLR axis may be a strategy to inhibit PDAC metastasis by blocking triglyceride synthesis.

High prevalence of APOA1/C3/A4/A5 alterations in luminal breast cancers among young women in East Asia

In East Asia, the breast cancer incidence rate among women aged <50 years has rapidly increased. Emerging tumors are distinctly characterized by a high prevalence of estrogen receptor (ER)-positive/human epidermal growth factor receptor (HER2)-negative cancer. In the present study, we identified unique genetic alterations in these emerging tumors. We analyzed gene copy number variations (CNVs) in breast tumors from 120 Taiwanese patients, and obtained public datasets of CNV and gene expression (GE). The data regarding CNV and GE were separately compared between East Asian and Western patients, and the overlapping genes identified in the comparisons were explored to identify the gene-gene interaction networks. In the age <50 years/ER + /HER2- subgroup, tumors of East Asian patients exhibited a higher frequency of copy number loss in APOA1/C3/A4/A5, a lipid-metabolizing gene cluster (33 vs. 10%, P < .001) and lower APOA1/C3/A4/A5 expressions than tumors of Western patients. These copy number loss related- and GE-related results were validated in another Taiwanese cohort and in two GE datasets, respectively. The copy number loss was significantly associated with poor survival among Western patients, but not among East Asian patients. Lower APOA1, APOC3, and APOA5 expressions were associated with higher ESTIMATE immune scores, indicating an abundance of tumor-infiltrating immune cells. In conclusion, APOA1/C3/A4/A5 copy number loss was more prevalent in luminal breast tumors among East Asian women aged <50 years, and its immunomodulatory effect on the tumor microenvironment possibly plays various roles in the tumor biology of East Asian patients.

Prognostic and Therapeutic Value of Apolipoprotein A and a New Risk Scoring System Based on Apolipoprotein A and Adenosine Deaminase in Chronic Lymphocytic Leukemia

Lipid metabolism is related to lymphomagenesis, and is a novel therapeutic target in some hematologic tumors. Apolipoprotein A (ApoA), the major protein of high-density lipoprotein (HDL), plays a crucial role in lipid transportation and protecting against cardiovascular disease, and takes effect on anti-inflammation and anti-oxidation. It is correlated with the prognosis of some solid tumors. Yet, there is no investigation involving the role of ApoA plays in chronic lymphocytic leukemia (CLL). Our retrospective study focuses on the prognostic value of ApoA in CLL and its therapeutic potential for CLL patients. Herein, ApoA is a favorable independent prognostic factor for both overall survival (OS) and progression-free survival (PFS) of CLL patients. ApoA is negatively associated with β2-microglobulin (β2-MG) and advanced stage, which are poor prognostic factors in CLL. Age, Rai stage, ApoA, and adenosine deaminase (ADA) are included in a new risk scoring system named ARAA-score. It is capable of assessing OS and PFS of CLL patients. Furthermore, cell proliferation assays show that the ApoA-I mimetic L-4F can inhibit the proliferation of CLL cell lines and primary cells. In conclusion, ApoA is of prognostic value in CLL, and is a potential therapy for CLL patients. The ARAA-score may optimize the risk stratification of CLL patients.

Apolipoprotein mimetics in cancer

Peptides have many advantages over traditional therapeutics, including small molecules and other biologics, because of their low toxicity and immunogenicity, while still exhibiting efficacy. This review discusses the benefits and mechanism of action of apolipoprotein mimetic peptides in tumor biology and their potential utility in treating various cancers. Among lipoproteins in the circulation, high-density lipoprotein (HDL) and its constituents including apolipoprotein A-I (apoA-I; the predominant protein in HDL), apoJ, and apoE, harbor anti-tumorigenic activities. Peptides that mimic apoA-I function have been developed through molecular mimicry of the amphipathic α-helices of apoA-I. Oral apoA-I mimetic peptides remodel HDL, promote cholesterol efflux, sequester oxidized lipids, and activate anti-inflammatory processes. ApoA-I and apoJ mimetic peptides ameliorate various metrics of cancer progression and have demonstrated efficacy in preclinical models in the inhibition of ovarian, colon, breast, and metastatic lung cancers. Apolipoprotein mimetic peptides are poorly absorbed when administered orally and rapidly degraded when injected into the circulation. The small intestine is the major site of action for apoA-I mimetic peptides and recent studies suggest that modulation of immune cells in the lamina propria of the small intestine is, in part, a potential mechanism of action. Finally, several recent studies underscore the use of reconstituted HDL as target-specific nanoparticles carrying poorly soluble or unstable therapeutics to tumors even across the blood-brain barrier. Preclinical studies suggest that these versatile recombinant lipoprotein based nanoparticles and apolipoprotein mimetics can serve as safe, novel drug delivery, and therapeutic agents for the treatment of a number of cancers.

Identification of diagnostic and prognostic biomarkers, and candidate targeted agents for hepatitis B virus-associated early stage hepatocellular carcinoma based on RNA-sequencing data

Primary liver cancer is a rapidly progressing neoplasm with high morbidity and mortality rates. The present study aimed to identify potential diagnostic and prognostic biomarkers, and candidate targeted agents for hepatitis B virus (HBV)-associated early stage hepatocellular carcinoma (HCC). The gene expression profiles were extracted from the Gene Expression Omnibus database. Differentially expressed genes (DEGs), hub genes and the enrichment of signaling pathways were filtered out via a high-throughput sequencing method. The association between hub genes and the effects of the abnormal expression of hub genes on the rate of genetic variation, overall survival (OS), relapse-free survival (RFS), progression-free survival (PFS) and disease-free survival (DSS) of patients with HCC, as well as pathological stage and grade, were analyzed using different databases. A total of 1,582 DEGs were identified. Gene Ontology analysis revealed that the DEGs were mainly involved in the ‘oxidation-reduction process’, ‘steroid metabolic process’, ‘metabolic process’ and ‘fatty acid beta-oxidation’. Enrichment analysis of Kyoto Encyclopedia of Genes and Genomes pathways revealed that the DEGs were mainly associated with ‘metabolic pathways’, ‘PPAR signaling pathway’, ‘fatty acid degradation’ and the ‘cell cycle’. A total of 8 hub genes were extracted. Additionally, the abnormal expression levels of hub genes were closely associated with the OS, RFS, PFS and DSS of patients, the pathological stage and the grade. Furthermore, abnormal expression levels of the 8 hub genes were found in >30% of all samples. Several small molecular compounds that may reverse the altered DEGs were identified based on Connectivity Map analysis, including phenoxybenzamine, GW-8510, resveratrol, 0175029-0000 and daunorubicin. In conclusion, the dysfunction of fat metabolic pathways, the cell cycle, oxidation-reduction processes and viral carcinogenesis may serve critical roles in the occurrence of HBV-associated early stage HCC. The identified 8 hub genes may act as robust biomarkers for diagnosis and prognosis. Some small molecular compounds may be promising targeted agents against HBV-associated early stage HCC.

Bovine HDL and Dual Domain HDL-Mimetic Peptides Inhibit Tumor Development in Mice

A growing body of literature supports the role of apolipoproteins present in HDL in the treatment of pro-inflammatory diseases including cancer. We examined whether bovine HDL (bHDL) and three dual-domain peptides, namely AEM-28 and its analog AEM-28-2, and HM-10/10, affect tumor growth and development in mouse models of ovarian and colon cancer. We demonstrate that bHDL inhibits mouse colorectal cancer cell line CT26-mediated lung tumor development, and mouse ovarian cancer cell line ID8-mediated tumor burden. We also demonstrate that, although to different degrees, dual-domain peptides inhibit cell viability of mouse and human ovarian and colon cancer cell lines, but not that of normal human colonic epithelial cells or NIH3T3 mouse fibroblasts. Dual-domain peptides administered subcutaneously or in a chow diet decrease CT26 cell-mediated tumor burden, tumor growth, and tumor dissemination in BALB/c mice. Plasma levels of lysophosphatidic acid (LPA) are significantly reduced in mice that received bHDL and the dual-domain peptides, suggesting that reduction by effecting accumulation and/or synthesis of pro-inflammatory lipids may be one of the mechanisms for the inhibition of tumor development by bHDL and the dual-domain peptides. Our studies suggest that therapeutics based on apolipoproteins present in HDL may be novel agents for the treatment of epithelial adenocarcinomas of the ovary and colon.

A Novel HDL-Mimetic Peptide HM-10/10 Protects RPE and Photoreceptors in Murine Models of Retinal Degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness in the developed world. The retinal pigment epithelium (RPE) is a critical site of pathology in AMD. Oxidative stress plays a key role in the development of AMD. We generated a chimeric high-density lipoprotein (HDL), mimetic peptide named HM-10/10, with anti-oxidant properties and investigated its potential for the treatment of retinal disease using cell culture and animal models of RPE and photoreceptor (PR) degeneration. Treatment with HM-10/10 peptide prevented human fetal RPE cell death caused by tert-Butyl hydroperoxide (tBH)-induced oxidative stress and sodium iodate (NaIO₃), which causes RPE atrophy and is a model of geographic atrophy in mice. We also show that HM-10/10 peptide ameliorated photoreceptor cell death and significantly improved retinal function in a mouse model of N-methyl-N-nitrosourea (MNU)-induced PR degeneration. Our results demonstrate that HM-10/10 protects RPE and retina from oxidant injury and can serve as a potential therapeutic agent for the treatment of retinal degeneration.

Apolipoprotein A-I (ApoA-I), Immunity, Inflammation and Cancer

Apolipoprotein A-I (ApoA-I), the major protein component of high-density lipoproteins (HDL) is a multifunctional protein, involved in cholesterol traffic and inflammatory and immune response regulation. Many studies revealing alterations of ApoA-I during the development and progression of various types of cancer suggest that serum ApoA-I levels may represent a useful biomarker contributing to better estimation of cancer risk, early cancer diagnosis, follow up, and prognosis stratification of cancer patients. In addition, recent in vitro and animal studies disclose a more direct, tumor suppressive role of ApoA-I in cancer pathogenesis, which involves anti-inflammatory and immune-modulatory mechanisms. Herein, we review recent epidemiologic, clinicopathologic, and mechanistic studies investigating the role of ApoA-I in cancer biology, which suggest that enhancing the tumor suppressive activity of ApoA-I may contribute to better cancer prevention and treatment.

Diagnostic and prognostic significance of mRNA expressions of apolipoprotein A and C family genes in hepatitis B virus-related hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is among the most common and lethal malignancies worldwide. Apolipoproteins (APOs) have been reported increasingly for their relationships with tumors. We aim at exploring the potential relationships of apolipoprotein A (APOA) and apolipoprotein C (APOC) family members with HCC.

METHODS

A data set, containing 212 hepatitis B virus-related HCC patients, was used for analysis. The diagnostic and prognostic ability of APOA and APOC family genes was figured out. Risk score models and nomograms were developed for the HCC prognosis prediction. Moreover, molecular mechanism exploration were identified biological processes and metabolic pathways of these genes involved in. Validation analysis was carried out using online website.

RESULTS

APOA1, APOC1, APOC3, and APOC4 showed robust diagnosis significance (all P < 0.05). APOA4, APOC3, and APOC4 were associated with the overall survival (OS) while APOA4 and APOC4 were linked to recurrence-free survival (RFS, all P ≤ 0.05). Risk score models and nomograms had the advantage of predicting OS and RFS for HCC. Molecular mechanism exploration indicated that these genes were involved in the steroid metabolic process, the PPAR signaling pathway, and fatty acid metabolism. Besides that, validation analysis revealed that APOC1 and APOC4 had an association with OS; and APOC3 was associated with OS and RFS (all P ≤ 0.05).

CONCLUSIONS

APOA1, APOC1, APOC3, and APOC4 are likely to be potential diagnostic biomarkers and APOC3 and APOC4 are likely to be potential prognostic biomarkers for hepatitis B virus-related HCC. They may be involved in the steroid metabolic process, PPAR signaling pathway, and fatty acid metabolism.

AIBP and APOA-I synergistically inhibit intestinal tumor growth and metastasis by promoting cholesterol efflux

Background

The roles played by cholesterol in cancer development and progression represent a popular field in the cancer community. High cholesterol levels are positively correlated with the risk of various types of cancer. APOA-I binding protein (AIBP) promotes the reverse cholesterol transport pathway (RCT) in cooperation with Apolipoprotein A-I (APOA-I) or high-density lipoprotein cholesterol. However, the combined effect of AIBP and APOA-I on intestinal tumor cells is still unclear.

Methods

Immunohistochemistry, western blot and qPCR were performed to investigate the expression of AIBP and APOA-I in intestinal tumor tissues and cell lines. The anti-tumor activity of AIBP and APOA-I was evaluated by overexpression or recombinant protein treatment. Cholesterol efflux and localization of lipid raft-related proteins were analyzed by a cholesterol efflux assay and lipid raft fraction assay, respectively.

Results

Here, we reported that both AIBP expression and APOA-I expression were associated with the degree of malignancy in intestinal tumors. Co-overexpression of AIBP and APOA-I more potently inhibited colon cancer cell-mediated tumor growth and metastasis compared to overexpression of each protein individually. Additionally, the recombinant fusion proteins of AIBP and APOA-I exhibited a significant therapeutic effect on tumor growth in Apc^min/+ mice as an inherited intestinal tumor model. The synergistic effect of the two proteins inhibited colon cancer cell migration, invasion and tumor-induced angiogenesis by promoting cholesterol efflux, reducing the membrane raft content, and eventually disrupting the proper localization of migration- and invasion-related proteins on the membrane raft. Moreover, cyclosporine A, a cholesterol efflux inhibitor, rescued the inhibitory effect induced by the combination of AIBP and APOA-I.

Conclusions

These results indicate that the combination of APOA-I and AIBP has an obvious anticancer effect on colorectal cancer by promoting cholesterol efflux.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1910-7) contains supplementary material, which is available to authorized users.

Anti-tumorigenic and Platinum-Sensitizing Effects of Apolipoprotein A1 and Apolipoprotein A1 Mimetic Peptides in Ovarian Cancer

Objective: Apolipoprotein A1 (ApoA1) is remarkably decreased in serum and ovarian tissues of ovarian cancer patients. ApoA1 and ApoA1 mimetic peptides can sequestrate pro-inflammatory phospholipids, some of which are known to activate a variety of oncogenic pathways. Besides, more intrinsic anti-tumorigenic properties, independent from interaction with lipids, have also been described for ApoA1. We aimed to disclose the effects of ApoA1 and a mimetic peptide on the malignant phenotype of ovarian cancer cells, particularly regarding cell viability, invasiveness and platinum sensitization. Methods: Cells viability was assessed by MTS assay. Extracellular matrix invasion was assessed by transwell and spheroid invasion assays. Western blotting was performed to evaluate the effect of test compounds on intracellular pathways. Sensitization assays were performed in vitro and in the biologically relevant in ovo chorioallantoic membrane model. Results: Both ApoA1 and the mimetic peptide, at a concentration of 100 μg/mL, were able to decrease the viability of SKOV3, CAOV3, and OVCAR3 cells (p < 0.05). The peptide at this concentration was not able to affect the viability of immortalized non-neoplastic ovarian cells (p > 0.05). ApoA1 decreased SKOV3 cells invasiveness at 300 μg/mL after 72 and 96 h of exposure (p < 0.05), while the ApoA1 mimetic peptide prevented cell invasion at 50 and 100 μg/mL (p < 0.01). Treatment with 100 μg/mL of ApoA1 mimetic peptide decreased Akt phosphorylation in SKOV3 cells (p < 0.01). Accordingly, treatment with increasing concentrations of the peptide sensitized SKOV3, OVCAR3 and CAOV3 cells to cisplatin. This synergistic effect was observed both in vitro and in ovo. Conclusions: These results support the role of ApoA1 and ApoA1 mimetics as suppressors of ovarian tumorigenesis and as chemo-sensitising agents.

Dietary magnesium deficiency impaired intestinal structural integrity in grass carp (Ctenopharyngodon idella)

Grass carp (223.85–757.33 g) were fed diets supplemented with magnesium (73.54–1054.53 mg/kg) for 60 days to explore the impacts of magnesium deficiency on the growth and intestinal structural integrity of the fish. The results demonstrated that magnesium deficiency suppressed the growth and damaged the intestinal structural integrity of the fish. We first demonstrated that magnesium is partly involved in (1) attenuating antioxidant ability by suppressing Nrf2 signalling to decrease antioxidant enzyme mRNA levels and activities (except CuZnSOD mRNA levels and activities); (2) aggravating apoptosis by activating JNK (not p38MAPK) signalling to upregulate proapoptotic protein (Apaf-1, Bax and FasL) and caspase-2, -3, -7, -8 and -9 gene expression but downregulate antiapoptotic protein (Bcl-2, IAP and Mcl-1b) gene expression; (3) weakening the function of tight junctional complexes (TJs) by promoting myosin light chain kinase (MLCK) signalling to downregulate TJ gene expression [except claudin-7, ZO-2b and claudin-15 gene expression]. Additionally, based on percent weight gain (PWG), against reactive oxygen species (ROS), against caspase-9 and claudin-3c in grass carp, the optimal dietary magnesium levels were calculated to be 770.38, 839.86, 856.79 and 811.49 mg/kg, respectively.

Biomimetic nano-surfactant stabilizes sub-50 nanometer phospholipid particles enabling high paclitaxel payload and deep tumor penetration

Sub-50 nm nanoparticles feature long circulation and deep tumor penetration. However, at high volume fractions needed for intravenous injection, safe, highly biocompatible phospholipids cannot form such nanoparticles due to the fluidity of phospholipid shells. Here we overcome this challenge using a nano-surfactant, a sterilized 18-amino-acid biomimetic of the amphipathic helical motif abundant in HDL-apolipoproteins. As it induces a nanoscale phase (glass) transition in the phospholipid monolayer, the peptide stabilizes 5-7 nm phospholipid micelles that do not fuse at high concentrations but aggregate into stable micellesomes exhibiting size-dependent penetration into tumors. In mice bearing human Her-2-positive breast cancer xenografts, high-payload paclitaxel encapsulated in 25 nm (diameter) micellesomes kills more cancer cells than paclitaxel in standard clinical formulation, as evidenced by the enhanced apparent diffusion coefficient of water determined by in vivo MR imaging. Importantly, the bio-inertness of this biomimetic nano-surfactant spares the nanoparticles from being absorbed by liver hepatocytes, making them more generally available for drug delivery.

Treating the Intestine with Oral ApoA-I Mimetic Tg6F Reduces Tumor Burden in Mouse Models of Metastatic Lung Cancer

Having demonstrated that apolipoprotein A-I (apoA-I) mimetic peptides ameliorate cancer in mouse models, we sought to determine the mechanism for the anti-tumorigenic function of these peptides. CT-26 cells (colon cancer cells that implant and grow into tumors in the lungs) were injected into wild-type BALB/c mice. The day after injection, mice were either continued on chow or switched to chow containing 0.06% of a concentrate of transgenic tomatoes expressing the apoA-I mimetic peptide 6F (Tg6F). After four weeks, the number of lung tumors was significantly lower in Tg6F-fed mice. Gene expression array analyses of jejunum and lung identified Notch pathway genes significantly upregulated, whereas osteopontin (Spp1) was significantly downregulated by Tg6F in both jejunum and lung. In jejunum, Tg6F increased protein levels for Notch1, Notch2, Dll1, and Dll4. In lung, Tg6F increased protein levels for Notch1 and Dll4 and decreased Spp1. Tg6F reduced oxidized phospholipid levels (E06 immunoreactivity) and reduced 25-hydroxycholesterol (25-OHC) levels, which are known to inhibit Notch1 and induce Spp1, respectively. Notch pathway promotes anti-tumorigenic patrolling monocytes, while Spp1 facilitates pro-tumorigenic myeloid derived suppressor cells (MDSCs) formation. Tg6F-fed mice had higher numbers of patrolling monocytes in jejunum and in lung (p < 0.02), and lower plasma levels of Spp1 with reduced numbers of MDSCs in jejunum and in lung (p < 0.03). We conclude that Tg6F alters levels of specific oxidized lipids and 25-OHC to modulate Notch pathways and Spp1, which alter small intestine immune cells, leading to similar changes in lung that reduce tumor burden.

Preoperative serum apolipoprotein A-I levels predict long-term survival in non-muscle-invasive bladder cancer patients

Introduction

The aim of this study was to elucidate the association between apolipoprotein A-I (Apo A-I) and overall survival (OS) as well as cancer-specific survival (CSS) in non-muscle-invasive bladder cancer (NMIBC) patients undergoing transurethral resection of bladder tumor (TURBT).

Patients and methods

We retrospectively collected data of 470 eligible patients diagnosed with NMIBC and who received TURBT between January 2004 and December 2011. Pretreatment blood indexes were examined. The association of Apo A-I with clinicopathological characteristics was further analyzed by dichotomizing our sample into those with Apo A-I ≤ 1.19 g/L (low Apo A-I group) and those with Apo A-I > 1.19 g/L (high Apo A-I group). OS and CSS were estimated by Kaplan–Meier analysis and the log-rank test was used to compare differences between groups. Univariate and multivariate Cox regression analyses were plotted to assess the prognostic value of Apo A-I in NMIBC patients. In addition, subgroup analyses were performed according to the risk classification of the International Bladder Cancer Group.

Results

In the overall population, patients in the high Apo A-I group had greater 5-year OS and 5-year CSS rates as compared to those in the low Apo A-I group. Kaplan–Meier survival analysis revealed that higher albumin, Apo A-I, and hemoglobin levels were associated with greater OS and CSS while elevated neutrophil–lymphocyte ratio was associated with worse OS and CSS in the overall and high-risk population rather than low- and intermediate-risk population. Furthermore, Apo A-I was shown to be an independent predictor in the overall population (for OS, hazard ratio [HR], 0.364, 95% confidence interval [CI], 0.221–0.598, p < 0.001; for CSS, HR, 0.328, 95% CI, 0.185–0.583, p < 0.001) and high-risk patients (for OS, HR, 0.232, 95% CI 0.121–0.443, p < 0.001; for CSS, HR, 0.269, 95% CI, 0.133–0.541, p < 0.001).

Conclusion

These results suggest that Apo A-I level could potentially serve as a useful prognostic indicator for therapeutic decision making in NMIBC patients.

Methionine hydroxy analogue supplementation modulates gill immunological and barrier health status of grass carp (Ctenopharyngodon idella)

This study was conducted to investigate the effects of methionine hydroxy analogue (MHA) on the physical barrier and immune defence in the gill of young grass carp (Ctenopharyngodon idella). A total 630 young grass carp with an average initial weight of 259.70 ± 0.47 g were fed graded levels of MHA (0, 2.4, 4.4, 6.4, 8.5 and 10.5 g/kg diet) and one DL-methionine (DLM) group (6.4 g/kg diet) for 8 weeks. After feeding trial, 15 fish from each treatment were challenged with Flavobacterium columnare. Compared to the basal diet, optimal MHA improved cellular structure integrity of gill via repressing death receptor and mitochondria pathways induced apoptosis, which might be related to the down-regulation of c-Jun-N-terminal kinase mRNA levels (P < .05). Simultaneously, optimal MHA supplementation improved cellular structure integrity of gill via elevating glutathione contents, antioxidant enzymes activities and corresponding isoforms mRNA levels to attenuate oxidative damage, which might be to the up-regulation of NF-E2-related factor 2 mRNA levels and down-regulation of Kelch-like ECH-associating protein 1a mRNA levels (P < .05). Besides, optimal MHA improved intercellular structure integrity of immune organs via up-regulating the mRNA levels of intercellular tight junctions-related genes, which might be owing to the down-regulation of myosin light chain kinase (MLCK) mRNA levels (P < .05). Summarily, MHA could improve the physical barrier of fish gill. In addition, optimal MHA supplementation increased lysozyme (LZ) and acid phosphatase (ACP) activities, complement 3 (C3), C4 and immunoglobulin M contents and up-regulated mRNA levels of liver-expressed antimicrobial peptide 2, hepcidin and β-defensin, suggesting that MHA could enhance antimicrobial ability of fish gill. Meanwhile, optimal MHA supplementation enhanced the immune defence of gill via down-regulating pro-inflammatory cytokines mRNA levels and up-regulated anti-inflammatory cytokines mRNA levels, which might be attributed to the down-regulation of nuclear factor κB p65, c-Rel, IκB kinase β, p38 mitogen activated protein kinase, eIF4E-binding protein1 (4E-BP1) and 4E-BP2 mRNA levels and up-regulation of inhibitor of κBα, ribosomal protein S6 kinase 1 and target of rapamycin mRNA levels (P < .05). In conclusion, the positive effect of MHA on gill health is associated with the improvement of the defence against apoptosis, antioxidant status, tight junctions and immune defence of fish gill. Meanwhile, MHA was superior to DLM on improving the physical barrier of fish gill. For the direction to healthy breeding of young grass carp, the optimal MHA supplementation levels on the premise of 4.01 g/kg methionine basal were estimated by quadratic regression curve, such as 5.49, 6.17 and 6.02 g/kg diet bases on the defence against gill-rot, malondialdehyde content and LZ activity in the gill, respectively.

Methionine hydroxy analogue improves intestinal immunological and physical barrier function in young grass carp (Ctenopharyngodon idella)

This study was conducted to test the hypothesis that methionine hydroxy analogue (MHA) enhances the defense against enteritis occurrence via improving intestinal barrier function in fish. After 630 young grass carp (Ctenopharyngodon idella) (259.70 ± 0.47 g) fed six graded levels of MHA (0, 2.4, 4.4, 6.4, 8.5 and 10.5 g/kg diet) and one dl-methionine group (6.4 g/kg diet) for 8 weeks. At the end of feeding trial, 15 fish from each treatment were challenged with Aeromonas hydrophila for 14 days. The results indicated that optimal MHA enhanced the capacity of fish against enteritis emergence, which might be related to the positive effects of MHA on intestinal immunological and physical barrier function in fish. Dietary MHA supplementation enhanced intestinal immunological barrier function via (1) lysozyme (LZM) and acid phosphatase (ACP) activities, complement 3 (C3), C4 and immunoglobulin M (IgM) contents and up-regulated mRNA levels of liver-expressed antimicrobial peptide 2, hepcidin (head kidney), β-defensin-1; (2) repressing p38MAPK/IKKβ/IκBα/NF-κB signaling pathway to down-regulate pro-inflammatory cytokines mRNA levels except IL-8 mRNA level only in mid and distal intestine; (3) potentiating TOR-signal cascades to up-regulate anti-inflammatory cytokines. Meanwhile, dietary MHA supplementation improved intestinal physical barrier via (1) down-regulating c-Jun N-terminal kinase mRNA levels to inhibit death receptor and mitochondria pathways induced apoptosis; (2) modulating Keap1a/Nrf2 system to elevate antioxidant enzymes genes isoforms mRNA levels and corresponding enzymes activities, subsequently alleviate oxidative damage; (3) down-regulating MCLK gene expression to up-regulating occludin, zonula occluden 1 and claudins mRNA levels except claudin-7a and claudin-7b only in the proximal intestine. In conclusion, bases on the capacity defense against enteritis, proximal intestinal malondialdehyde content and lysozyme activity, the optimal MHA supplementation levels were 5.83, 5.59 and 6.07 g/kg diet (4.01 g/kg methionine basal), respectively. This study indicates that MHA exerts a positive effect on fish intestinal health status and a superior efficacy to dl-methionine based on the positive effects.

The apolipoprotein A-I mimetic peptide, D-4F, alleviates ox-LDL-induced oxidative stress and promotes endothelial repair through the eNOS/HO-1 pathway

Apolipoprotein A-I (apoA-I) mimetic peptide exerts many anti-atherogenic properties. However, the underlying mechanisms related to the endothelial protective effects remain elusive. In this study, the apoA-I mimetic peptide, D-4F, was used. Proliferation assay, wound healing, and transwell migration experiments showed that D-4F improved the impaired endothelial proliferation and migration resulting from ox-LDL. Endothelial adhesion molecules expression and monocyte adhesion assay demonstrated that D-4F inhibited endothelial inflammation. Caspase-3 activation and TUNEL stain indicated that D-4F reduced endothelial cell apoptosis. A pivotal anti-oxidant enzyme, heme oxygenase-1 (HO-1) was upregulated by D-4F. The Akt/AMPK/eNOS pathways were involved in the expression of HO-1 induced by D-4F. Moreover, the anti-oxidation, pro-proliferation, and pro-migration capacities of D-4F were diminished by the inhibitors of both eNOS (L-NAME) and HO-1 (Znpp). Additionally, downregulation of ATP-binding cassette transporter A1 (ABCA1) by siRNA abolished the activation of Akt, AMPK and eNOS, and reduced the upregulation of HO-1 triggered by D-4F. Furthermore, D-4F promoted the reendothelialization of injured intima in carotid artery injury model of C57BL/6J mice in vivo. In summary, these findings suggested that D-4F might be a powerful candidate in the protection of endothelial cells and the prevention of cardiovascular disease (CVD).

Methionine hydroxy analogue enhanced fish immunity via modulation of NF-κB, TOR, MLCK, MAPKs and Nrf2 signaling in young grass carp (Ctenopharyngodon idella)

Our study investigated the effect of dietary methionine hydroxy analogue (MHA) on growth and immunity (head kidney, spleen and skin) of young grass carp (Ctenopharyngodon idella). A total of 630 grass carp (259.70 ± 0.47 g) were fed graded levels of MHA (0, 2.4, 4.4, 6.4, 8.5 and 10.5 g/kg diet) and one dl-methionine (DLM) group (6.4 g/kg diet) for 8 weeks. At the end of the feeding trial, fish were challenged with Aeromonas hydrophila for 14 days. The results indicated that optimal MHA increased lysozyme (LZ) and acid phosphatase (ACP) activities, complement 3 (C3), C4 and immunoglobulin M (IgM) contents and up-regulated mRNA levels of liver expressed antimicrobial peptide 2, hepcidin (head kidney), β-defensin-1 in the immune organs (P < 0.05), suggesting that MHA could enhance antimicrobial ability of fish. Meanwhile, optimal MHA enhanced the immune function of immune organs via down-regulating pro-inflammatory cytokines mRNA levels and up-regulated anti-inflammatory cytokines mRNA levels, which might be attributed to the down-regulation of nuclear factor κB p65, c-Rel, IκB kinase β, p38 mitogen activated protein kinase, eIF4E-binding protein1 (4E-BP1) and 4E-BP2 mRNA levels and up-regulation of inhibitor of κBα, ribosomal protein S6 kinase 1 and target of rapamycin mRNA levels (P < 0.05). In addition, optimal MHA improved cellular structure integrity of immune organs via repressing death receptor and mitochondria pathways induced apoptosis, which might be related to the down-regulation of c-Jun-N-terminal kinase mRNA levels (P < 0.05). Simultaneously, optimal MHA improved cellular structure integrity of immune organs via elevating glutathione contents, antioxidant enzymes activities and corresponding isoforms mRNA levels to attenuate oxidative damage, which might be to the up-regulation of NF-E2-related factor 2 mRNA levels and down-regulation of Kelch-like ECH-associating protein 1a mRNA levels (P < 0.05). Besides, optimal MHA improved intercellular structure integrity of immune organs via up-regulating the mRNA levels of intercellular tight junctions-related genes, which might be owing to the down-regulation of myosin light chain kinase mRNA levels (P < 0.05). In conclusion, MHA exerted a positive effect on the immune function and structural integrity of immune organs in fish. Furthermore, according to the positive effect, MHA was superior to DLM in grass carp. However, based on the growth performance, the efficacy of MHA relative to DLM was 97%. Finally, on the premise of the basal diet containing 4.01 g/kg methionine, the optimal MHA supplementation levels based on feed intake, PWG, defense against skin hemorrhage and lesion, LZ and ACP activities, IgM content, against malondialdehyde, protein carbonyl and ROS in the head kidney of young grass carp were 5.07, 5.21, 5.76, 5.90, 5.88, 5.80, 6.22, 5.68 and 6.85 g/kg diet, respectively.

Apolipoprotein A-I and Cancer

High-density lipoprotein (HDL) and apolipoprotein A-I (apoA-I), the predominant protein in plasma HDL, have long been the focus of intense studies in the field of atherosclerosis and cardiovascular disease. ApoA-I, in large part, is responsible for HDL assembly and its main atheroprotective function, that of shuttling excess cholesterol from peripheral tissues to the liver for excretion (reverse cholesterol transport). Recently, a protective role for HDL in cancer was suggested from several large clinical studies where an inverse relationship between plasma HDL-cholesterol (HDL-C) levels and risk of developing cancer was noted. This notion has now been tested and found to be supported in mouse tumor studies, where increasing levels of apoA-I/HDL were discovered to protect against tumor development and provision of human apoA-I was therapeutic against established tumors. This mini-review discusses the emerging role of apoA-I in tumor biology and its potential as cancer therapeutic.

Efficacy of tomato concentrates in mouse models of dyslipidemia and cancer

We previously reported that adding freeze-dried tomato powder from transgenic plants expressing the apolipoprotein A-I mimetic peptide 6F at 2.2% by weight to a Western diet (WD) ameliorated dyslipidemia and atherosclerosis in mice. The same dose in a human would require three cups of tomato powder three times daily. To reduce the volume, we sought a method to concentrate 6F. Remarkably, extracting the transgenic freeze-dried tomato overnight in ethyl acetate with 5% acetic acid resulted in a 37-fold reduction in the amount of transgenic tomato needed for biologic activity. In a mouse model of dyslipidemia, adding 0.06% by weight of the tomato concentrate expressing the 6F peptide (Tg6F) to a WD significantly reduced plasma total cholesterol and triglycerides (P < 0.0065). In a mouse model of colon cancer metastatic to the lungs, adding 0.06% of Tg6F, but not a control tomato concentrate (EV), to standard mouse chow reduced tumor-associated neutrophils by 94 ± 1.1% (P = 0.0052), and reduced tumor burden by two-thirds (P = 0.0371). Adding 0.06% of either EV or Tg6F by weight to standard mouse chow significantly reduced tumor burden in a mouse model of ovarian cancer; however, Tg6F was significantly more effective (35% reduction for EV vs. 53% reduction for Tg6F; P = 0.0069). Providing the same dose of tomato concentrate to humans would require only two tablespoons three times daily making this a practical approach for testing oral apoA-I mimetic therapy in the treatment of dyslipidemia and cancer.

Apolipoprotein A-I mimetics

PURPOSE OF REVIEW

To summarize recent publications in the field of apolipoprotein mimetics.

RECENT FINDINGS

Apolipoprotein mimetic peptides continue to show efficacy in a number of animal models of disease and demonstrate properties that make them attractive as potential therapeutic agents. A number of new apolipoprotein mimetics have been described recently. A major site of action of apolipoprotein mimetic peptides was found to be in the small intestine in which they decrease the levels of proinflammatory bioactive lipids. A major problem related to the use of apolipoprotein mimetic peptides is their cost, particularly those that need to be generated by solid phase synthesis with chemical addition of end-blocking groups. Novel approaches to apolipoprotein mimetic therapy have emerged recently that show promise in overcoming these barriers.

SUMMARY

Despite the recent failure of therapies designed to raise HDL-cholesterol in humans, an approach to therapy using mimetics of HDL and its components continues to show promise.

APOA1 mRNA expression in ovarian serous carcinoma effusions is a marker of longer survival

OBJECTIVES

We previously described the overexpression of APOA1 and GPX3 in ovarian/peritoneal serous carcinoma compared with breast carcinoma effusions using gene expression array analysis. The objective of the present study was to validate this finding and to analyze the association between these genes and clinicopathologic parameters, including survival, in advanced-stage ovarian serous carcinoma.

METHODS

APOA1 and GPX3 mRNA expression using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was analyzed in 121 effusions (101 ovarian, 20 breast carcinomas) and 85 solid ovarian carcinoma specimens (43 primary carcinomas, 42 metastases).

RESULTS

APOA1 and GPX3 transcript levels were significantly higher in ovarian carcinoma at all anatomic sites compared with breast carcinoma effusions (P < .001). GPX3 mRNA levels were significantly higher in primary carcinomas and solid metastases from patients who received neoadjuvant chemotherapy compared with chemo-naïve tumors (P = .016). APOA1 and GPX3 mRNA levels in the entire effusion series were unrelated to clinicopathologic parameters. However, higher APOA1 mRNA levels in primary diagnosis pre-chemotherapy effusions were significantly related to better overall survival (P = .045), a finding that retained its significance in Cox multivariate analysis (P = .016).

CONCLUSIONS

APOA1 and GPX3 mRNA levels on qRT-PCR effectively differentiate ovarian from breast carcinoma. APOA1 may be a novel prognostic marker in metastatic serous carcinoma.

Manganese superoxide dismutase in cancer prevention

SIGNIFICANCE

Cancer is the second leading cause of death in the United States. Considering the quality of life and treatment cost, the best way to fight against cancer is to prevent or suppress cancer development. Cancer is preventable as indicated by human papilloma virus (HPV) vaccination and tamoxifen/raloxifen treatment in breast cancer prevention. The activities of superoxide dismutases (SODs) are often lowered during early cancer development, making it a rational candidate for cancer prevention.

RECENT ADVANCES

SOD liposome and mimetics have been shown to be effective in cancer prevention animal models. They've also passed safety tests during early phase clinical trials. Dietary supplement-based SOD cancer prevention provides another opportunity for antioxidant-based cancer prevention. New mechanistic studies have revealed that SOD inhibits not only oncogenic activity, but also subsequent metabolic shifts during early tumorigenesis.

CRITICAL ISSUES

Lack of sufficient animal model studies targeting specific cancers; and lack of clinical trials and support from pharmaceutical industries also hamper efforts in further advancing SOD-based cancer prevention.

FUTURE DIRECTIONS

To educate and obtain support from our society that cancer is preventable. To combine SOD-based therapeutics with other cancer preventive agents to obtain synergistic effects. To formulate a dietary supplementation-based antioxidant approach for cancer prevention. Lastly, targeting specific populations who are prone to carcinogens, which can trigger oxidative stress as the mechanism of carcinogenesis.

Ursolic acid promotes cancer cell death by inducing Atg5-dependent autophagy

Ursolic acid (UA) has been reported to possess anticancer activities. Although some of the anticancer activities of UA have been explained by its apoptosis-inducing properties, the mechanisms underlying its anticancer actions are largely unknown. We have found that UA-activated autophagy induced cytotoxicity and reduced tumor growth of cervical cancer cells TC-1 in a concentration-dependent manner. UA did not induce apoptosis of TC-1 cells in vitro as determined by annexin V/propidium iodide staining, DNA fragmentation, and Western blot analysis of the apoptosis-related proteins. We found that UA increased punctate staining of light chain 3 (LC3), which is an autophagy marker. LC3II, the processed form of LC3I which is formed during the formation of double membranes, was induced by UA treatment. These results were further confirmed by transmission electron microscopy. Wortmannin, an inhibitor of autophagy, and a small interfering RNA (siRNA) for autophagy-related genes (Atg5) reduced LC3II and simultaneously increased the survival of TC-1 cells treated with UA. We also found that LC3II was significantly reduced and that survival was increased in Atg5-/- mouse embryonic fibroblast (MEF) cells compared to Atg5+/+ MEF cells under UA treatment. However, silencing BECN1 by siRNA affected neither the expression of LC3II nor the survival of TC-1 cells under UA treatment. These results suggest that autophagy is a major mechanism by which UA kills TC-1 cells. It is Atg5 rather than BECN1 that plays a crucial role in UA-induced autophagic cell death in TC-1 cells. The activation of autophagy by UA may become a potential cancer therapeutic strategy complementing the apoptosis-based therapies. Furthermore, regulation of Atg5 may improve the efficacy of UA in cancer treatment.

Recombinant lipoproteins reinforce cytotoxicity of doxorubicin to hepatocellular carcinoma

Cancer nanotherapeutics are changing the landscape of tumor treatment and used to circumvent limitations of conventional chemotherapy, such as non-specificity and low bioavailability. Reconstituted high density lipoproteins (rHDL) system is one of the most promising targeting delivery systems of chemotherapeutic drugs toward tumors. Here, we developed recombined high-density lipoprotein which can be functionalized to deliver doxorubicin intracellular with a higher efficiency. The cellular viability assay showed that the rHDL/Dox nanovectors had an enhanced efficiency in inhibiting the cell viability of hepatocellular carcinoma cell lines HepG2 and SMMC-7721. FACS and confocal microscopy was used to observe the doxorubicin delivery into cancer cells. Intracellular drug accumulation analysis confirmed that treatment of rHDL/Dox nanovectors resulted in higher intracellular doxorubicin concentration to the levels exceeding that of free drug. On the premise of efficient drug delivery, rHDL/Dox nanovectors have been preliminarily demonstrated effective inducing of cytotoxic effect and cell apoptosis to both of the cell lines in vitro. Tissue distribution experiment showed that rHDL/Dox nanovectors could also deliver doxorubicin to liver effectively. So, we proposed that this lipoprotein-based strategy holds promise for a safer and more efficient delivery of chemotherapeutic agents in the treatment of hepatocellular carcinoma.

Apolipoprotein A1 as a potential biomarker in the ascitic fluid for the differentiation of advanced ovarian cancers

CONTEXT

Primary ovarian cancer and ovarian metastasis from non-ovarian cancers in advanced stage are closely mimicking conditions whose therapeutics and prognosis are different.

OBJECTIVE

To identify biomarkers that can differentiate the two variants of advanced ovarian cancers.

METHODS

Gel-based proteomics and antibody-based assays were used to study the differentially expressed proteins in the ascitic fluid of fourteen patients with advanced ovarian cancers.

RESULTS

Programmed Cell Death 1-Ligand 2, apolipoprotein A1, apolipoprotein A4 and anti-human fas antibody are differentially expressed proteins.

CONCLUSIONS

Apolipoprotein A1 with a 61.8 ng/ml cut-off is a potential biomarker with the best differentiating statistical parameters.

Scavenger receptor B1 is a potential biomarker of human nasopharyngeal carcinoma and its growth is inhibited by HDL-mimetic nanoparticles

Nasopharyngeal carcinoma (NPC) is a very regional malignant head and neck cancer that has attracted widespread attention for its unique etiology, epidemiology and therapeutic options. To achieve high cure rates in NPC patients, theranostic approaches are actively being pursued and improved efforts remain desirable in identifying novel biomarkers and establishing effective therapeutic approaches with low long-term toxicities. Here, we discovered that the scavenger receptor class B type I (SR-B1) was overexpressed in all investigated NPC cell lines and 75% of NPC biopsies, demonstrating that SR-B1 is a potential biomarker of NPC. Additional functional analysis showed that SR-B1 has great effect on cell motility while showing no significant impact on cell proliferation. As high-density lipoproteins (HDL) exhibit strong binding affinities to SR-B1 and HDL mimetic peptides are reportedly capable of inhibiting tumor growth, we further examined the SR-B1 targeting ability of a highly biocompatible HDL-mimicking peptide-phospholipid scaffold (HPPS) nanocarrier and investigated its therapeutic effect on NPC. Results show that NPC cells with higher SR-B1 expression have superior ability in taking up the core constituents of HPPS. Moreover, HPPS inhibited the motility and colony formation of 5-8F cells, and significantly suppressed the NPC cell growth in nude mice without inducing tumor cell necrosis or apoptosis. These results indicate that HPPS is not only a NPC-targeting nanocarrier but also an effective anti-NPC drug. Together, the identification of SR-B1 as a potential biomarker and the use of HPPS as an effective anti-NPC agent may shed new light on the diagnosis and therapeutics of NPC.

An apolipoprotein A-I mimetic targets scavenger receptor A on tumor-associated macrophages: A prospective anticancer treatment?

Tumor-associated macrophages polarize toward an M2 phenotype and express scavenger receptor A (SRA), hence promoting tumor progression. We demonstrated that SRA can be therapeutically targeted in vivo with the small peptide inhibitor 4F to prevent metastatic spread. Beyond our study, 4F is emerging as a promising anticancer agent.

Macrophage scavenger receptor a promotes tumor progression in murine models of ovarian and pancreatic cancer

Alternatively activated macrophages express the pattern recognition receptor scavenger receptor A (SR-A). We demonstrated previously that coculture of macrophages with tumor cells upregulates macrophage SR-A expression. We show in this study that macrophage SR-A deficiency inhibits tumor cell migration in a coculture assay. We further demonstrate that coculture of tumor-associated macrophages and tumor cells induces secretion of factors that are recognized by SR-A on tumor-associated macrophages. We tentatively identified several potential ligands for the SR-A receptor in tumor cell-macrophage cocultures by mass spectrometry. Competing with the coculture-induced ligand in our invasion assay recapitulates SR-A deficiency and leads to similar inhibition of tumor cell invasion. In line with our in vitro findings, tumor progression and metastasis are inhibited in SR-A(-/-) mice in two in vivo models of ovarian and pancreatic cancer. Finally, treatment of tumor-bearing mice with 4F, a small peptide SR-A ligand able to compete with physiological SR-A ligands in vitro, recapitulates the inhibition of tumor progression and metastasis observed in SR-A(-/-) mice. Our observations suggest that SR-A may be a potential drug target in the prevention of metastatic cancer progression.

Oxidative stress in apoptosis and cancer: an update

The oxygen paradox tells us that oxygen is both necessary for aerobic life and toxic to all life forms. Reactive oxygen species (ROS) touch every biological and medical discipline, especially those involving proliferative status, supporting the idea that active oxygen may be increased in tumor cells. In fact, metabolism of oxygen and the resulting toxic byproducts can cause cancer and death. Efforts to counteract the damage caused by ROS are gaining acceptance as a basis for novel therapeutic approaches, and the field of prevention of cancer is experiencing an upsurge of interest in medically useful antioxidants. Apoptosis is an important means of regulating cell numbers in the developing cell system, but it is so important that it must be controlled. Normal cell death in homeostasis of multicellular organisms is mediated through tightly regulated apoptotic pathways that involve oxidative stress regulation. Defective signaling through these pathways can contribute to both unbalance in apoptosis and development of cancer. Finally, in this review, we discuss new knowledge about recent tools that provide powerful antioxidant strategies, and designing methods to deliver to target cells, in the prevention and treatment of cancer.

Apolipoprotein A-I mimetic peptides inhibit expression and activity of hypoxia-inducible factor-1α in human ovarian cancer cell lines and a mouse ovarian cancer model

Our previous results demonstrated that the apolipoprotein A-I (apoA-I) mimetic peptides L-4F and L-5F inhibit vascular endothelial growth factor production and tumor angiogenesis. The present study was designed to test whether apoA-I mimetic peptides inhibit the expression and activity of hypoxia-inducible factor-1α (HIF-1α), which plays a critical role in the production of angiogenic factors and angiogenesis. Immunohistochemistry staining was used to examine the expression of HIF-1α in tumor tissues. Immunoblotting, real-time polymerase chain reaction, immunofluorescence, and luciferase activity assays were used to determine the expression and activity of HIF-1α in human ovarian cancer cell lines. Immunohistochemistry staining demonstrated that L-4F treatment dramatically decreased HIF-1α expression in mouse ovarian tumor tissues. L-4F inhibited the expression and activity of HIF-1α induced by low oxygen concentration, cobalt chloride (CoCl(2), a hypoxia-mimic compound), lysophosphatidic acid, and insulin in two human ovarian cancer cell lines, OV2008 and CAOV-3. L-4F had no effect on the insulin-induced phosphorylation of Akt, but inhibited the activation of extracellular signal-regulated kinase and p70s6 kinase, leading to the inhibition of HIF-1α synthesis. Pretreatment with L-4F dramatically accelerated the proteasome-dependent protein degradation of HIF-1α in both insulin- and CoCl(2)-treated cells. The inhibitory effect of L-4F on HIF-1α expression is in part mediated by the reactive oxygen species-scavenging effect of L-4F. ApoA-I mimetic peptides inhibit the expression and activity of HIF-1α in both in vivo and in vitro models, suggesting the inhibition of HIF-1α may be a critical mechanism responsible for the suppression of tumor progression by apoA-I mimetic peptides.

Apolipoprotein A-I mimetics and high-density lipoprotein function

PURPOSE OF REVIEW

To review recently published advances in the development of apolipoprotein A-I (apoA-I) mimetic peptides as a potential treatment for cardiovascular diseases.

RECENT FINDINGS

Various apoA-I mimetic peptides are currently in development and these display potent cardioprotective features that can rival or even surpass those of full length apoA-I and high-density lipoproteins (HDLs). These features include the ability to efflux cholesterol from various cell types as well as anti-inflammatory and antioxidative properties. Recent work has been aimed at identifying the structural features of these peptides that are responsible for these various functions and also for determining the operational mechanisms. There is also interesting new data suggesting that the intestine may be playing an important role in the action of these peptides.

SUMMARY

In the last year, there have been many important advances in the relatively new field of apoA-I mimetic therapy. These findings support a strong potential for their development as treatment for not only cardiovascular disease but other disease states involving chronic inflammation and oxidation as well.

HDL mimetics inhibit tumor development in both induced and spontaneous mouse models of colon cancer

Recent studies suggest that high-density lipoprotein (HDL) levels are inversely related to colon cancer risk. HDL mimetics constructed from a number of peptides and proteins with varying structures possess anti-inflammatory and antioxidant properties reminiscent of HDL. In this article, we examined whether HDL mimetics, L-4F (an apolipoprotein A-I mimetic peptide) and G* (an apolipoprotein J mimetic peptide) affect tumor growth and development in mouse models of colon cancer. HDL mimetics reduced viability and proliferation of CT26 cells, a mouse colon adenocarcinoma cell line, and decreased CT26 cell-mediated tumor burden in BALB/c mice when administered subcutaneously or orally. Plasma levels of lysophosphatidic acid (LPA), a serum biomarker for colon cancer, were significantly reduced in mice that received HDL mimetics, suggesting that binding and removal of proinflammatory lipids is a potential mechanism for the inhibition of tumor development by HDL mimetics. Furthermore, L-4F significantly reduced size and number of polyps in APC(min/+) mice, a mouse model for human familial adenomatous polyposis, suggesting that HDL mimetics are effective in inhibiting the development of both induced and spontaneous cancers of the colon. Our results, for the first time, identify HDL mimetics as a novel therapeutic strategy for the treatment of colon cancer.

Boswellia sacra essential oil induces tumor cell-specific apoptosis and suppresses tumor aggressiveness in cultured human breast cancer cells

Background

Gum resins obtained from trees of the Burseraceae family (Boswellia sp.) are important ingredients in incense and perfumes. Extracts prepared from Boswellia sp. gum resins have been shown to possess anti-inflammatory and anti-neoplastic effects. Essential oil prepared by distillation of the gum resin traditionally used for aromatic therapy has also been shown to have tumor cell-specific anti-proliferative and pro-apoptotic activities. The objective of this study was to optimize conditions for preparing Boswellea sacra essential oil with the highest biological activity in inducing tumor cell-specific cytotoxicity and suppressing aggressive tumor phenotypes in human breast cancer cells.

Methods

Boswellia sacra essential oil was prepared from Omani Hougari grade resins through hydrodistillation at 78 or 100 ^oC for 12 hours. Chemical compositions were identified by gas chromatography-mass spectrometry; and total boswellic acids contents were quantified by high-performance liquid chromatography. Boswellia sacra essential oil-mediated cell viability and death were studied in established human breast cancer cell lines (T47D, MCF7, MDA-MB-231) and an immortalized normal human breast cell line (MCF10-2A). Apoptosis was assayed by genomic DNA fragmentation. Anti-invasive and anti-multicellular tumor properties were evaluated by cellular network and spheroid formation models, respectively. Western blot analysis was performed to study Boswellia sacra essential oil-regulated proteins involved in apoptosis, signaling pathways, and cell cycle regulation.

Results

More abundant high molecular weight compounds, including boswellic acids, were present in Boswellia sacra essential oil prepared at 100 ^oC hydrodistillation. All three human breast cancer cell lines were sensitive to essential oil treatment with reduced cell viability and elevated cell death, whereas the immortalized normal human breast cell line was more resistant to essential oil treatment. Boswellia sacra essential oil hydrodistilled at 100 ^oC was more potent than the essential oil prepared at 78 ^oC in inducing cancer cell death, preventing the cellular network formation (MDA-MB-231) cells on Matrigel, causing the breakdown of multicellular tumor spheroids (T47D cells), and regulating molecules involved in apoptosis, signal transduction, and cell cycle progression.

Conclusions

Similar to our previous observations in human bladder cancer cells, Boswellia sacra essential oil induces breast cancer cell-specific cytotoxicity. Suppression of cellular network formation and disruption of spheroid development of breast cancer cells by Boswellia sacra essential oil suggest that the essential oil may be effective for advanced breast cancer. Consistently, the essential oil represses signaling pathways and cell cycle regulators that have been proposed as therapeutic targets for breast cancer. Future pre-clinical and clinical studies are urgently needed to evaluate the safety and efficacy of Boswellia sacra essential oil as a therapeutic agent for treating breast cancer.

Dysfunctional high-density lipoprotein and the potential of apolipoprotein A-1 mimetic peptides to normalize the composition and function of lipoproteins

Although high-density lipoprotein-cholesterol (HDL-C) levels in large epidemiological studies are inversely related to the risk of coronary heart disease (CHD), increasing the level of circulating HDL-C does not necessarily decrease the risk of CHD events, CHD deaths, or mortality. HDL can act as an anti- or a pro-inflammatory molecule, depending on the context and environment. Based on a number of recent studies, it appears that the anti- or pro-inflammatory nature of HDL may be a more sensitive indicator of the presence or absence of atherosclerosis than HDL-C levels. The HDL proteome has been suggested to be a marker, and perhaps a mediator, of CHD. Apolipoprotein A-1 (apoA-I), the major protein in HDL is a selective target for oxidation by myeloperoxidase, which results in impaired HDL function. Improving HDL function through modification of its lipid and/or protein content maybe a therapeutic target for the treatment of CHD and many inflammatory disorders. HDL/apoA-I mimetic peptides may have the ability to modify the lipid and protein content of HDL and convert dysfunctional HDL to functional HDL. This review focuses on recent studies of dysfunctional HDL in animal models and human disease, and the potential of apoA-I mimetic peptides to normalize the composition and function of lipoproteins.