Fasting mimicking diet inhibits tumor-associated macrophage survival and pro-tumor function in hypoxia: implications for combination therapy with anti-angiogenic agent.

BACKGROUND: Recent research shows that tumor-associated macrophages (TAMs) are the primary consumers of glucose in tumor tissue, surpassing that of tumor cells. Our previous studies revealed that inhibiting glucose uptake impairs the survival and tumor-promoting function of hypoxic TAMs, suggesting that glucose reduction by energy restriction (calorie restriction or short-term fasting) may has a significant impact on TAMs. The purpose of this study is to verify the effect of fasting-mimicking diet (FMD) on TAMs, and to determine whether FMD synergizes with anti-angiogenic drug apatinib via TAMs. METHODS: The effect of FMD on TAMs and its synergistic effects with apatinib were observed using an orthotopic mouse breast cancer model. An in vitro cell model, utilizing M2 macrophages derived from THP-1 cell line, was intended to assess the effects of low glucose on TAMs under hypoxic and normoxic conditions. Bioinformatics was used to screen for potential mechanisms of action, which were then validated both in vivo and in vitro. RESULTS: FMD significantly inhibit the pro-tumor function of TAMs in vivo and in vitro, with the inhibitory effect being more pronounced under hypoxic conditions. Additionally, the combination of FMD-mediated TAMs inhibition with apatinib results in synergistic anti-tumor activity. This effect is partially mediated by the downregulation of CCL8 expression and secretion by the mTOR-HIF-1α signaling pathway. CONCLUSIONS: These results support further clinical combination studies of FMD and anti-angiogenic therapy as potential anti-tumor strategies.

Size-resolved gas-particle partitioning characteristics of typical semi-volatile organic compounds in urban atmosphere.

Understanding particle size distribution and size-resolved gas-particle partitioning of semi-volatile organic compounds (SVOCs) is important for characterizing their fate in atmosphere. However, the size-resolved gas-particle partitioning characteristics of SVOCs has not been adequately considered. To address this issue, the present study collected gaseous and size-fractioned particulate samples both in and outside of schools, offices, and residences in three districts of different urbanization levels in a megacity, Guangzhou, South China during two seasons. Typical SVOCs, including 15 polycyclic aromatic hydrocarbons (PAHs), six organophosphate esters and seven phthalic acid esters were measured. Emission sources, physicochemical properties, and environmental conditions at the sampling sites considerably impacted the spatiotemporal distribution patterns and particle size distribution of target SVOCs. Not all observed gas-particle partition coefficients (Kp) of target SVOCs were negatively correlated with subcooled liquid-vapor pressures (PL0), probably because certain factors, such as the non-exchangeable part of the particle-bound SVOCs, were not considered in traditional gas-particle partition theories. Particle size was an important factor affecting gas-particle partitioning. Adsorption was the dominant mechanism for PAHs with high molecular weight in different particle modes. A new model was established to predict size-resolved Kp of PAHs with high molecular weight based on PL0 and particle size.

Comprehensive two-dimensional APTES-decorated MCF7-cell membrane chromatographic system for characterizing potential anti-breast-cancer components from Yuanhu-Baizhi herbal medicine pair.

Rhizoma corydalis and Radix Angelicae Dahurica (Yuanhu-Baizhi) herbal medicine pair has been used for thousands of years and has been reported to be potentially active in recent cancer therapy. But the exact active components or fractions remain unclear. In this study, a new comprehensive two-dimensional (2D) 3-aminopropyltriethoxysilane (APTES)-decorated MCF7-cell membrane chromatography (CMC)/capcell-C18 column/time-of-flight mass spectrometry system was established for screening potential active components and clarifying the active fraction of Yuanhu-Baizhi pair. APTES was modified on the surface of silica, which can provide an amino group to covalently link cell membrane fragments with the help of glutaraldehyde in order to improve the stability and column life span of the MCF7 CMC column. The comprehensive 2D MCF7-CMC system showed good separation and identification abilities. Our screen results showed that the retention components are mainly from the alkaloids in Yuanhu (12 compounds) and the coumarins (10 compounds) in Baizhi, revealing the active fractions of Yuanhu-Baizhi herbal medicine pair. Oxoglaucine, protopine, berberine, osthole, isopimpinellin and palmitic acid were selected as typical components to test the effects on cell proliferation and their IC50 were calculated as 38.17 µM, 29.45 µM, 45.42 µM, 132.7 µM, 156.8 µM and 90.5 µM respectively. Cell apoptosis assay showed that the drug efficacy was obtained mainly through inducing cell apoptosis. Furthermore, a synergistic assay results demonstrated that oxoglaucine (representative of alkaloids from Yuanhu) and isopimpinellin (representative of coumarins from Baizhi) showed significant synergistic efficacy with GFT, indicating that these components may act on other membrane receptors. The proposed 2D CMC system could also be equipped with other cells for further applications. Besides, the follow-up in-vitro experimental strategy using cell proliferation assay, cell apoptosis assay and synergistic assay proved to be a practical way to confirm the active fractions of herbal medicine.

An amphipathic lytic peptide for enhanced and selective delivery of ellipticine.

Cationic lytic peptides (CLPs) have shown promise in treating bacterial infection and cancer via selective disruption of bacterial or cancer cell membranes. In this work, we used a CLP, C6, as a nanocarrier for a hydrophobic anticancer agent, ellipticine (EPT). The size of the resulting C6-EPT complex was ∼190 nm. The in vitro studies using A549 lung cancer cells showed an enhanced anticancer activity of the C6-EPT complex compared to that of C6 or the EPT control. This enhancement was found to correlate with the membrane disruption induced by C6, which facilitated the entry of EPT into cells. More importantly, the C6-EPT complex showed a higher selectivity than that of C6 towards cancer cells upon comparison of their cytotoxicities against A549 cells and NIH-3T3 fibroblast cells. The enhanced therapeutic activity was also found in in vivo studies using an A549 tumor-bearing BALB/c nude mice model. This study provides a new CLP strategy for the development of multifunctional drug delivery systems.

Inhibitory effects of salvianolic acid B on CCl(4)-induced hepatic fibrosis through regulating NF-κB/IκBα signaling.

ETHNOPHARMACOLOGICAL RELEVANCE: Hepatic fibrosis, a precursor of liver cirrhosis, is a consequence of severe liver damage that occurs in many patients with chronic liver diseases. Salvianolic acid B (SA-B) is one of water soluble compounds derived from Salvia miltiorrhiza Bunge (Danshen in Chinese) widely used for chronic liver diseases. In this study we investigated the protective effects of SA-B on CCl(4)-induced hepatic fibrosis. MATERIALS AND METHODS: Hepatic fibrosis in rats was induced by carbon tetrachloride (CCl(4)). Rats were divided into four groups, including normal controls (N group), model (M group), low SA-B of 10mg/kg body weight (L group), or high SA-B of 20mg/kg body weight (H group). After 6 weeks, macroscopic features of the liver and weight ratio of liver to body were measured. Liver fibrosis of the rats was evaluated by HE and Massion staining. Activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) were checked with automated biochemistry analyzer. Serum levels of hyaluronic acid (HA), type IV collagen (IV-C), Laminin (LN) and procollagen III peptide (PIIIP) were detected by radioimmunoassay (RIA). The expression of NF-κB and IκBα was detected by western blotting. RESULTS: SA-B was shown to reduce CCl(4)-induced hepatic fibrosis in rats. The serum levels of ALT, AST, and TBIL were significantly lower in the SA-B treatment groups than in the M group. Compared the M group, the serum levels of HA, LN, IV-C and PIIIP were decreased markedly after treatment with SA-B, especially in the H group. Treatment with SA-B at 10-20mg/kg (L and N groups, respectively) dose-dependently decreased the expression of NF-κB in the nucleolus and increased the expression levels of NF-κB and IκBα protein in the cytoplasm compared to that of the M group. CONCLUSIONS: This study reveals that SA-B could prevent the progression of liver angiogenesis and alleviate liver fibrosis possibly by regulating the expression of NF-κB and IκBα.

Antitumor activity and immunomodulatory effects of the intraperitoneal administration of Kanglaite in vivo in Lewis lung carcinoma.

AIMS OF THE STUDY: Kanglaite (KLT) is a useful antitumor drug with proven effects when combined with chemotherapy, radiotherapy or surgery. We hypothesize that KLT has antitumor activity and immunomodulatory effects in Lewis lung carcinoma. MATERIALS AND METHODS: C57BL/6 mice with Lewis lung carcinoma were divided into four groups: the control group (C), cisplatin group (1 mg/kg, DDP), low KLT group (6.25 ml/kg body weight [L]), and high KLT group (12.5 ml/kg body weight [H]). T cell proliferation was determined by the MTT assay. Nuclear factor-kappa B (NF-κB), inhibitor kappa B alpha (IκBα), IκB kinase (IKK) and epidermal growth factor receptor (EGFR) levels were measured by western blotting. An enzyme-linked immunosorbent assay was used to analyze the expression of interleukin-2 (IL-2). RESULTS: Intraperitoneal KLT significantly inhibited the growth of Lewis lung carcinoma, and the spleen index was significantly higher in the L and H groups than in the C group. KLT stimulated T cell proliferation in a dose-dependent manner. Treatment with KLT at either 6.25 or 12.5 ml/kg decreased the level of NF-κB in the nucleus in a dose-dependent manner, and KLT markedly decreased the expression of IκBα, IKK and EGFR in the cytoplasm of tumor cells and overall. IL-2 was significantly increased in the supernatant of splenocytes in the H group. CONCLUSIONS: These results demonstrate that KLT has pronounced antitumor and immunostimulatory activities in C57BL/6 mice with Lewis lung carcinoma. These may affect the regulation of NF-κB/IκB expression, in addition to cytokines such as IL-2 and EGFR. Further work needs to investigate the relevant signaling pathway effects, but our findings suggest that KLT may be a promising antitumor drug for clinical use.

Self-assembling peptide-based nanoparticles enhance anticancer effect of ellipticine in vitro and in vivo.

BACKGROUND AND METHODS: Applications of the anticancer agent, ellipticine, have been limited by its hydrophobicity and toxicity. An efficient delivery system is required to exploit the enormous potential of this compound. Recently, EAK16-II, an ionic-complementary, self-assembling peptide, has been found to stabilize ellipticine in aqueous solution. Here, the anticancer activity of ellipticine encapsulated in EAK16-II (EAK-EPT) was evaluated in vitro and in vivo. RESULTS: Our cellular uptake, toxicity, and apoptosis results in an A549 human lung carcinoma cell line indicate that EAK-EPT complexes are significantly more effective than treatment with EAK16-II or ellipticine alone. This is due to the ability of EAK16-II to stabilize ellipticine in a protonated state in well formed nanostructures approximately 200 nm in size. In vivo observations in an A549 nude mouse tumor model show higher antitumor activity and lower cytotoxicity of EAK-EPT complexes than in the control group treated with ellipticine alone. Tumor growth in animals was significantly inhibited after treatment with EAK-EPT complexes, and without any apparent side effects. CONCLUSION: The anticancer activity observed in this study coupled with minimal side effects encourages further development of peptide-mediated delivery of anticancer drugs, ellipticine in the present case, for clinical application.