Ji Eun Hong

Dietary fat increases solid tumor growth and metastasis of 4T1 murine mammary carcinoma cells and mortality in obesity-resistant BALB/c mice

IntroductionHigh-fat diets (HFDs) are known to cause obesity and are associated with breast cancer progression and metastasis. Because obesity is associated with breast cancer progression, it is important to determine whether dietary fat per se stimulates breast cancer progression in the absence of obesity. This study investigated whether an HFD increases breast cancer growth and metastasis, as well as mortality, in obesity-resistant BALB/c mice.MethodsThe 4-week-old, female BALB/c mice were fed HFD (60% kcal fat) or control diet (CD, 10% kcal fat) for 16 weeks. Subsequently, 4T1 mammary carcinoma cells were injected into the inguinal mammary fat pads of mice fed continuously on their respective diets. Cell-cycle progression, angiogenesis, and immune cells in tumor tissues, proteases and adhesion molecules in the lungs, and serum cytokine levels were analyzed with immunohistochemistry, Western blotting, and enzyme-linked immunosorbent assay (ELISA). In vitro studies were also conducted to evaluate the effects of cytokines on 4T1 cell viability, migration, and adhesion.ResultsSpleen and gonadal fat-pad weights, tumor weight, the number and volume of tumor nodules in the lung and liver, and tumor-associated mortality were increased in the HFD group, with only slight increases in energy intake and body weight. HF feeding increased macrophage infiltration into adipose tissues, the number of lipid vacuoles and the expression of cyclin-dependent kinase (CDK)2, cyclin D1, cyclin A, Ki67, CD31, CD45, and CD68 in the tumor tissues, and elevated serum levels of complement fragment 5a (C5a), interleukin (IL)-16, macrophage colony-stimulating factor (M-CSF), soluble intercellular adhesion molecule (sICAM)-1, tissue inhibitors of metalloproteinase (TIMP)-1, leptin, and triggering receptor expressed on myeloid cells (TREM)-1. Protein levels of the urokinase-type plasminogen activator, ICAM-1, and vascular cell adhesion molecule-1 were increased, but plasminogen activator inhibitor-1 levels were decreased in the lungs of the HFD group. In vitro assays using 4T1 cells showed that sICAM-1 increased viability; TREM-1, TIMP-1, M-CSF, and sICAM-1 increased migration; and C5a, sICAM-1, IL-16, M-CSF, TIMP-1, and TREM-1 increased adhesion.ConclusionsDietary fat increases mammary tumor growth and metastasis, thereby increasing mortality in obesity-resistant mice.

The Hexane Extract of Saussurea lappa and Its Active Principle, Dehydrocostus Lactone, Inhibit Prostate Cancer Cell Migration

Saussurea lappa has been used in Chinese traditional medicine for the treatment of abdominal pain, tenesmus, nausea, and cancer; previous studies have shown that S. lappa also induces G(2) growth arrest and apoptosis in gastric cancer cells. In this study, we investigated the effects of hexane extracts of S. lappa (HESLs) on the migration of DU145 and TRAMP-C2 prostate cancer cells. DU145 and TRAMP-C2 cells were cultured in the presence of 0-4 μg/mL HESL with or without 10 ng/mL epidermal growth factor (EGF). HESL inhibited the basal and EGF-induced migration of prostate cancer cells in a dose-dependent manner, whereas HESL did not influence the viability of these cancer cells under the conditions used in this study. Active fractions of HESL were separated via column chromatography, and the structure of the active principle was determined using (1)H and (13)C nuclear magnetic resonance spectroscopy. The active compound, dehydrocostus lactone (DHCL), in fraction 7 dose-dependently inhibited the basal and EGF-induced migration of prostate cancer cells. HESL and DHCL reduced matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 secretion but increased TIMP-2 levels in both the absence and presence of EGF. Our results demonstrate that the inhibition of MMP-9 secretion and the stimulation of TIMP-2 secretion contribute to reduced migration of DU145 cells treated with HESL and DHCL. These results indicate that HESL containing its active principle, DHCL, has potential as an antimetastatic agent for the treatment of prostate cancer.

Rubus coreanus Miquel ameliorates scopolamine-induced memory impairments in ICR mice.

The present study investigated the effect of Rubus coreanus Miquel (RCM) on scopolamine-induced memory impairments in ICR mice. Mice were orally administrated RCM for 4 weeks and scopolamine was intraperitoneally injected into mice to induce memory impairment. RCM improved the scopolamine-induced memory impairment in mice. The increase of acetylcholinesterase activity caused by scopolamine was significantly attenuated by RCM treatment. RCM increased the levels of acetylcholine in the brain and serum of mice. The expression of choline acetyltransferase, phospho-cyclic AMP response element-binding protein, and phospho-extracellular signal-regulated kinase was significantly increased within the brain of mice treated with RCM. The brain antioxidant enzyme activity decreased by scopolamine was increased by RCM. These results demonstrate that RCM exerts a memory-enhancing effect via the improvement of cholinergic function and the potentiated antioxidant activity in memory-impaired mice. The results suggest that RCM may be a useful agent for improving memory impairment.

Escin Suppresses Migration and Invasion Involving the Alteration of CXCL16/CXCR6 Axis in Human Gastric Adenocarcinoma AGS Cells

Escin, a natural mixture of triterpene saponins isolated from horse chestnut, has been reported to possess anticancer activity in many human cancer cells. However, the effect of escin on the metastasis has not been studied. The present study examined the effect of escin on the migration and invasion of AGS human gastric cancer cells. To examine the effects of escin on metastatic capacities of gastric cancer cells, AGS cells were cultured in the presence of 0–4 μmol/L escin. Escin inhibited cell migration and invasion in AGS cells. However, escin did not affect the viability of these cells at these concentrations. The chemokine receptor and its ligands play an important role in cancer metastasis. Escin decreased the production of soluble C-X-C motif chemokine (CXCL)16 but increased the expression of trans-membranous CXCL16. The expression of C-X-C chemokine receptor (CXCR)6 was not affected by escin treatment. Exogenous CXCL16 reversed escin-induced migration inhibition. In addition, escin inhibited the phosphorylation of focal adhesion kinase and Akt. These results demonstrate that escin inhibited the migration and invasion of AGS cells, which is associated with altered CXCL16/CXCR6 axis. These findings suggest that escin has potential as an antimetastatic agent in gastric cancer.

Biological features of core networks that result from a high-fat diet in hepatic and pulmonary tissues in mammary tumour-bearing, obesity-resistant mice

We previously demonstrated that the chronic consumption of a high-fat diet (HFD) promotes lung and liver metastases of 4T1 mammary carcinoma cells in obesity-resistant BALB/c mice. To examine early transcriptional responses to tumour progression in the liver and lungs of HFD-fed mice, 4-week-old female BALB/c mice were divided into four groups: sham-injected, control diet (CD)-fed; sham-injected, HFD-fed (SH); 4T1 cell-injected, CD-fed (TC); 4T1 cell-injected, HFD-fed (TH). Following 16 weeks of either a CD or HFD, 4T1 cells were injected into the mammary fat pads of mice in the TC and TH groups and all mice were continuously fed identical diets. At 14 d post-injection, RNA was isolated from hepatic and pulmonary tissues for microarray analysis of mRNA expression. Functional annotation and core network analyses were conducted for the TH/SH Unique gene set. Inflammation in hepatic tissues and cell mitosis in pulmonary tissues were the most significant biological functions in the TH/SH Unique gene set. The biological core networks of the hepatic TH/SH Unique gene set were characterised as those genes involved in the activation of acute inflammatory responses (Orm1, Lbp, Hp and Cfb), disordered lipid metabolism and deregulated cell cycle progression. Networks of the pulmonary Unique gene set displayed the deregulation of cell cycle progression (Cdc20, Cdk1 and Bub1b). These HFD-influenced alterations may have led to favourable conditions for the formation of both pro-inflammatory and pro-mitotic microenvironments in the target organs that promote immune cell infiltration and differentiation, as well as the infiltration and proliferation of metastatic tumour cells.

A functional egg yolk powder containing an antibody against Niemann-Pick C1-like1 (NPC1L1) lowers cholesterol levels in high cholesterol diet induced hypercholesterolemic SD rats

Niemann-Pick C1-Like 1 (NPC1L1) plays an important role in intestinal cholesterol absorption, and is a promising therapeutic target for treatment of hypercholesterolemia. A functional egg yolk powder containing an antibody against NPC1L1 (FEY) was investigated for lowering cholesterol levels in high cholesterol diet induced hypercholesterolemic rats. Male Sprague-Dawley rats (5 weeks old) were fed with control, high cholesterol (HCD), HCD+0.1% FEY, HCD+1% FEY, or HCD+5% FEY diets for 6 weeks. There was no effect of FEY on body weight gain, food intake, or liver, kidney, and spleen weights in hypercholesterolemic rats. FEY lowered total cholesterol and LDL-cholesterol serum levels, and the atherogenic index. FEY decreased hepatic cholesterol levels and hepatic lipid accumulation. Fecal cholesterol levels were increased by administration of FEY, which has potential as a cholesterol lowering agent for treatment of hypercholesterolemia.

Abstract 5562: High-fat diet feeding increases tumor growth and metastasis of mammary carcinoma cells in the 4T1 orthotopic BALB/c mouse model

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL We previously observed that chronic consumption of a high fat-diet (HFD) increased the breast cancer-related mortality in the 4T1 orthotopic mouse breast cancer model. In the present study, we determined whether feeding mice with a HFD for a prolonged period increases solid tumor growth and metastasis of breast cancer cells using the 4T1 orthotopic model. 4-week old, female BALB/c mice were fed a purified diet containing 60 kcal% fat (HFD) or 10 kcal% fat (control diet) for a period of 16 weeks. After 16 weeks, 4T1 mammary carcinoma cells (5 × 104 cells) were injected into the inguinal mammary fat pad of syngeneic female BALB/c mice and the mice were continuously fed the same diets. Solid tumor growth was increased in the HFD group as compared to the control diet group. Additionally, chronic consumption of the HFD markedly increased the number and volume of tumor nodules in the lung and liver. The expression of cyclin-dependent kinase (CDK)2, CDK4, cyclin D1, cyclin A, Ki67, vascular endothelial growth factor, CD31 (an angiogenesis marker), and CD45 (a monocyte/macrophage marker) was markedly increased in the tumor tissues in the HFD group as compared to control diet group. The protein levels of urokinase-type plasminogen activator (uPA), intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule-1 were significantly increased but those of plasminogen activator inhibitor-1 were decreased in the lung tissues of the HFD group as compared to control diet group. The serum levels of complement fragment 5a (C5a), interleukin (IL)-6, macrophage colony stimulating factor (M-CSF), soluble intercellular adhesion molecule (sICAM)-1, tissue inhibitors of metalloproteinase (TIMP)-1, and triggering receptor expressed on myeloid cells (TREM)-1 were up-regulated in the HFD group as compared to control diet group. We conducted in vitro assays to determine effect of these cytokines, which had been increased in the sera of mice fed on the HFD, on the cell proliferation, adhesion, and migration of 4T1 cells. sICAM-1 increased the viability of 4T1 cells. TREM-1, M-CSF, and sICAM-1 significantly increased the migration of 4T1 cells. Additionally, the capacity of 4T1 cells to adhere to strips coated with human collagen type I was increased by C5a, sICAM-1, IL-16, M-CSF, TIMP-1, and TREM-1. These results indicate that, in addition to adhesion molecules, metalloproteases and pro-angiogenic factors, the cytokines C5a, sICAM-1, IL-16, M-CSF, TIMP-1, and TREM-1 play important roles in the metastasis of mammary cancer cells in mice fed on a HFD for a prolonged period. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5562. doi:10.1158/1538-7445.AM2011-5562

Abstract 1444: Benzyl isothiocyanate inhibits tumor growth and lung metastasis of 4T1 murine mammary carcinoma cells in a BALB/c mouse xenograft model

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Benzyl isothiocyanate (BITC) is a hydrolysis product of glucotropaeolin found in cruciferous vegetables, and has been reported to have anti-tumor properties. In our previous study, we observed that BITC inhibited growth and metastatic capacity of breast cancer cells in vitro cell culture models. The present study examined the in vivo effects of BITC administration on tumor growth and metastasis of breast cancer cells. To establish the in vivo breast cancer model, 4T1 mammary carcinoma cells (5 × 104 cells) were injected into the inguinal mammary fat pad of syngeneic female BALB/c mice. One day later, the mice were divided into 3 groups and subjected to gavage with BITC (0, 5 or 10 mg/kg body weight/day) for 4 weeks. Oral administration of BITC significantly reduced the volume and weight of solid 4T1 cell tumors in BALB/c mice. BITC administration decreased the expression of proliferating cell nuclear antigen, Bcl-2, CD31 and VEGF, but increased the levels of Bax, cleaved caspase-3, −7, −9 and cleaved PARP in the tumors. In addition, Oral administration of BITC resulted in a significant reduction in the numbers of pulmonary tumor nodules and total pulmonary metastatic volume. To understand the mechanisms by which BITC exerts antimetastatic effects, metastasis-related proteins in the sera and lungs were measured by utilizing the relevant ELISA kits and Western blot analysis, respectively. BITC treatment significantly decreased the concentrations of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1, and urokinase-type plasminogen activator (uPA) in the sera of mice injected with 4T1 cells. However, the concentrations of TIMP-2 and plasminogen activator inhibitor (PAI)-1 were increased in the sera of mice treated with BITC. Additionally, the administration of BITC reduced the levels of MMP-2, MMP-9, TIMP-1, and uPA and increased TIMP-2 and PAI-1 in the lungs of these animals. In this study, we have demonstrated that BITC profoundly suppresses the tumor growth and lung metastasis in mice bearing orthotopic xenografts of 4T1 breast cancer cells. The present results indicate that BITC has potential as an anti-cancer agent for the treatment of breast cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1444.