Isochlorogenic Acid C Reverses Epithelial-Mesenchymal Transition via Down-regulation of EGFR Pathway in MDA-MB-231 cells.

BACKGROUND/AIM: Epidermal growth factor receptor (EGFR) has been suggested to play an important role in survival, proliferation, migration, differentiation, and tumorigenesis of many cell types. Breast cancer patients with high EGFR expression have a poor prognosis. In this study, we investigated the molecular mechanism of the inhibitory effect of isochlorogenic acid c (ICAC) extracted from Lonicera japonica on elevated EGFR levels of the triple-negative breast cancer (TNBC) cell line, MDA-MB-231. MATERIALS AND METHODS: The cell viability and cell-cycle analysis were evaluated using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay and flow cytometry, respectively. The migration ability and invasiveness of ICAC-treated MDA-MB-231 were examined by migration and Matrigel invasion assay. The epithelial-mesenchymal-transition (EMT)-related protein expression was examined by western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: ICAC led to significant morphological changes and suppressed migration and invasion capacities of highly metastatic MDA-MB-231 cells. Western blot analysis for EGFR/EMT-associated proteins suggested that ICAC attenuated the mesenchymal traits as observed by up-regulation of epithelial markers and down-regulation of mesenchymal markers as well as decreased activities of matrix metalloproteinase-9 (MMP-9). CONCLUSION: These results suggested that the inhibitory effects of ICAC against EGFR-induced EMT and MDA-MB-231 cell invasion were dependent on the EGFR/ phospholipase Cγ (PLCγ)/extracellular regulated protein kinase ½ (ERK½)/slug signaling pathway. Therefore, the obtained results could provide us clues for the next therapeutic strategy in the treatment of TNBC.

Amelioration of estrogen-deficiency-induced obesity by Ocimum gratissimum.

Objectives: Menopausal transition in women initiates with declining estrogen levels and is followed by significant changes in their physiological characteristics. These changes often lead to medical conditions, such as obesity, which is correlated with chronic low-grade/subclinical inflammation. Ocimum gratissimum L. is a food spice or traditional herb in many countries; the plant is rich in antioxidants, which possess anti-inflammation activities and multitude of other therapeutic functions. Methods: In this study, we evaluated effects of O. gratissimum extract (OGE) in preventing obesity by using ovariectomized (OVX) animal models to mimic menopausal women. Methods: OVX rats showed increase in body weight and in adipocyte size in perigonadal adipose tissue (p <0.05) and decrease in uterus weight. By contrast, OGE (0.2 mg/ml) significantly reduced body weight gain and adipocyte in OVX rats and showed insignificant changes in uterus weight. Further investigation indicated that OGE exerted no influence on levels of dorsal fat, serum total cholesterol, and serum triacylglycerol and on serum biochemical factors, calcium, phosphorus, and glucose. Conclusion: These findings suggested that OGE dietary supplements may be useful in controlling body weight of menopausal women.

Amelioration of estrogen deficiency-induced obesity by collagen hydrolysate.

Objectives: Menopausal transition with declining estrogen levels significantly affects the physiological properties of women and consequently contributes to a series of medical conditions, including obesity. Obesity is a crucial risk factor associated with cardiovascular diseases, diabetes mellitus, and breast cancer. Increasing dietary protein content improves satiety and energy expenditure. Thus, we hypothesize that supplementing with collagen, a common dietary protein, may alleviate menopause-induced obesity. Methods: We used ovariectomized (OVX) rats to mimic a menopausal human. The body weight of OVX rats significantly increased compared with that of sham-operated rats (P<0.05), but uterus weight was decreased. Adipocyte size in perigonadal adipose tissue also increased (P<0.05). Results: By contrast, OVX rats supplemented with aqueous collagen hydrolysate (2.5 mg/mL) exhibited significant attenuation in body weight gain and adipocyte enlargement (P<0.05), but insignificant change in uterus weight. Further investigation indicated that collagen hydrolysate supplementation insignificantly affected the levels of dorsal fat, serum total cholesterol, and serum triacylglycerol. Levels of serum biochemical factors, calcium, phosphorus, and glucose were also insignificantly altered by collagen hydrolysate supplementation. Conclusion: Collagen hydrolysate supplementation reduced body weight gain and adipocyte enlargement in response to ovariectomy but slightly affected blood lipids, calcium, and glucose in both sham-operated and OVX rats. Collagen hydrolysate supplementation is beneficial in ameliorating estrogen deficiency-induced obesity and its associated risk factors.

MZF-1/Elk-1 interaction domain as therapeutic target for protein kinase Cα-based triple-negative breast cancer cells.

Recent reports demonstrate that the expression of protein kinase C alpha (PKCα) in triple-negative breast cancer (TNBC) correlates with decreased survival outcomes. However, off-target effects of targeting PKCα and limited understanding of the signaling mechanisms upstream of PKCα have hampered previous efforts to manipulate this ubiquitous gene. This study shows that the expression of both myeloid zinc finger 1 (MZF-1) and Ets-like protein-1 (Elk-1) correlates with PKCα expression in TNBC. We found that the acidic domain of MZF-1 and the heparin-binding domain of Elk-1 facilitate the heterodimeric interaction between the two genes before the complex formation binds to the PKCα promoter. Blocking the formation of the heterodimer by transfection of MZF-160-72 or Elk-1145-157 peptide fragments at the MZF-1 / Elk-1 interface decreases DNA-binding activity of the MZF-1 / Elk-1 complex at the PKCα promoter. Subsequently, PKCα expression, migration, tumorigenicity, and the epithelial-mesenchymal transition potential of TNBC cells decrease. These subsequent effects are reversed by transfection with full-length PKCα, confirming that the MZF-1/Elk-1 heterodimer is a mediator of PKCα in TNBC cells. These data suggest that the next therapeutic strategy in treating PKCα-related cancer will be developed from blocking MZF-1/Elk-1 interaction through their binding domain.

Protective effects of Ocimum gratissimum polyphenol extract on carbon tetrachloride-induced liver fibrosis in rats.

Ocimum gratissimum found in tropical regions is a traditional herb commonly which prevents free radical damage and protects liver from oxidative stress and fibrosis. Ocimum gratissimum polyphenol extract (OGPE) was purified by resin tube to 33.24% polyphenol and 8.2% flavonoid, which were three-fold higher compared with the pre-purification concentrations. The abstract was used to determine if the antioxidant components in the O. gratissimum extract (OGE) were responsible for protective effects on liver fibrosis. High-performance liquid chromatography analysis revealed that the content levels of catechin, caffeic acid and epicatechin in OGPE also increased three-fold. Male Wistar rats were administered with carbon tetrachloride (CCl4) and varying amounts of OGPE doses [0-12 mg/kg body weight (BW)] or OGE dose (40 mg/kg BW) for 8 weeks. Results showed that OGPE at 12 mg/kg BW, similar to OGE at 40 mg/kg BW, maintained the liver weight, significantly ameliorated CCl4-induced steatosis, and mitigated other pathological changes. OGPE (12 mg/kg BW) also maintained the levels of serum alanine aminotransferase and aspartate aminotransferase, as well as the levels of malondialdehyde, catalase and α-smooth muscle actin in liver tissues from CCl4-induced changes. These findings suggest that antioxidant components in OGPE were the major factors that prevented liver fibrosis. Moreover, higher polyphenol concentrations were necessary for higher effectiveness.

Resistin-induced stromal cell-derived factor-1 expression through Toll-like receptor 4 and activation of p38 MAPK/ NFκB signaling pathway in gastric cancer cells.

BACKGROUND: Stromal cell-derived factor-1 (SDF-1) (CXC chemokine ligand-12)/CXC chemokine receptor 4 (CXCR4) is involved in the carcinogenesis of human gastric cancer, where it stimulates angiogenesis and favors metastasis of tumor cells to distant organs. In addition, resistin is suggested to be an important link between obesity and the development of gastric cancer. Resistin has identified as an important player in inflammatory responses, and emerged as a mediator in inflammation-associated cancer. A limited number of studies have investigated the association of resistin and SDF-1 with gastric cancer. Herein, we investigated the molecular mechanisms by which resistin influences the expression of SDF-1 in gastric carcinoma cells. RESULTS: Human gastric cancer cell lines were exposed to doses of resistin; SDF-1 expression and secretion levels were then determined. Real-time polymerase chain reaction and western blotting analyses were performed to clarify molecular changes. Inhibition of Toll-like receptor 4 (TLR4) by a competitive antagonist inhibited resistin-induced SDF-1 expression. Pharmacological inhibitors and small interfering RNA (siRNA) demonstrated that activation of the p38 mitogen-activated protein kinase (MAPK) pathway is critical for resistin-induced SDF-1 expression mediated by TLR4. The promoter activity and transcription factor enzyme-linked immunosorbent assay revealed that resistin induced expression of SDF-1 mediated by NF-κB in gastric cancer cells. Inhibition of p38 MARK activation blocked the SDF-1-induced expression and the SDF-1 promoter activity in the cancer gastric cells. Chromatin immunoprecipitation assay revealed that inhibition of p38 MARK activation also blocked the resistin-increased NF-κB-DNA-binding activity. CONCLUSIONS: Resistin-induced SDF-1 upregulation by activation of TLR4, p38 MARK and NF-κB may explain a new role of resistin in the link of obesity and gastric cancer.

Adipose-derived stem cells: isolation, characterization, and differentiation potential.

In mammals, the two main types of adipose tissues, white and brown adipose tissues, exert different physiological functions. White adipose tissue (WAT) is for storing energy, while brown adipose tissue (BAT) is for energy consumption. Adipose-derived stem cells (ADSCs) are abundant in WAT and BAT, have multipotent characteristics, and are easily extracted. ADSCs can be differentiated into several cell lineages, including adipocytes, osteoblasts, chondrocytes (cartilage cells), myocytes, and neuronal cells. Therefore, ADSC could be considered as a strategy for future regenerative medicine and tissue engineering.

Expression of protein kinase Cα and the MZF-1 and elk-1 transcription factors in human bladder transitional cell carcinoma cells.

In a recent study on hepatocellular carcinoma (HCC), we have shown that the transcription factors Myeloid Zinc Finger-1 (MZF-1) and Ets-like-protein 1 (Elk-1) are significantly related to protein kinase C alpha (PKCα) expression. The purpose of this study was to determine the correlation of the expression of PKCα with the expression of Elk-1 and MZF-1 in various differentiated urinary bladder transitional cell carcinoma (TCC) cell lines: 5637, BFTC905, TSGH8301, HT1376 and HT1197 cells. The malignant potential in the five TCC cell lines was examined by using cell proliferation/migration/invasion assay and the protein and mRNA levels of PKCα, ElK-1 and MZF-1 were examined by Western blot and RT-PCR analysis. The results showed that the rate of cell proliferation in the TSGH8301 cell line was higher than that in other cell lines, while there were obvious signs of cell migration and invasion in 5637, BFTC905 and HT1376 cells, and no sign in TSGH8301 and HT1197 cells. The resulting expression levels of Elk-1 and PKCα were the highest in 5637 cells, but the MZF-1 expression observed in all five cell lines showed no significant difference. To determine whether a correlation exists between PKCα and Elk-1, a shRNA knockout assay was performed and the results showed that the reduction of Elk-1 expression in 5637 cells did not result in the decreased PKCα expression. Therefore, although the findings showed elevated expression of Elk-1 and PKCα in 5637 cells, the regulator of PKCα in bladder cancer cells is yet to be determined.

Expression of protein kinase C α and the MZF-1 and Elk-1 transcription factors in human breast cancer cells.

Recently, our research into hepatocellular carcinoma (HCC) has shown that the transcription factors Myeloid Zinc Finger-1 (MZF-1) and Ets-like-protein 1 are related to protein kinase C alpha (PKCα) expression. The purpose of this study was to determine the correlation of the expression of PKCαwith the expressions of Elk-1 and MZF-1 in various differentiated breast cancer cell lines: MDA- MB-231, Hs57BT, SKBR3, MDA-MB-468 and MCF-7. The malignant potential in the five lines of breast cancer cells was examined by using a cell proliferation/migration/invasion assay and the protein and mRNA levels of PKCα, ElK-1 and MZF-1 were examined by Western blot and RT-PCR analysis, re- spectively. The results showed that there were obvious signs of migration and invasion of cells in MDA- MB-231 and Hs57BT cells, little signs of cell migration and invasion in MDA-MB-468 cells, and no sign in SKBR3 and MCF-7 cells. Moreover, the highest expression levels of PKCα, Elk-1 and MZF-1 were also observed in MDA-MB-231 and Hs57BT cells when compared to the other breast cancer cell lines. These findings confirm that elevated expression of PKCαin breast cancer cells may be correlated with the potential of cell migration and invasion, and suggest an association between the expression of PKCα and the expression of the transcription factors Elk-1 and MZF-1.

Baicalein inhibits the migration and invasive properties of human hepatoma cells.

Flavonoids have been demonstrated to exert health benefits in humans. We investigated whether the flavonoid baicalein would inhibit the adhesion, migration, invasion, and growth of human hepatoma cell lines, and we also investigated its mechanism of action. The separate effects of baicalein and baicalin on the viability of HA22T/VGH and SK-Hep1 cells were investigated for 24h. To evaluate their invasive properties, cells were incubated on matrigel-coated transwell membranes in the presence or absence of baicalein. We examined the effect of baicalein on the adhesion of cells, on the activation of matrix metalloproteinases (MMPs), protein kinase C (PKC), and p38 mitogen-activated protein kinase (MAPK), and on tumor growth in vivo. We observed that baicalein suppresses hepatoma cell growth by 55%, baicalein-treated cells showed lower levels of migration than untreated cells, and cell invasion was significantly reduced to 28%. Incubation of hepatoma cells with baicalein also significantly inhibited cell adhesion to matrigel, collagen I, and gelatin-coated substrate. Baicalein also decreased the gelatinolytic activities of the matrix metalloproteinases MMP-2, MMP-9, and uPA, decreased p50 and p65 nuclear translocation, and decreased phosphorylated I-kappa-B (IKB)-ß. In addition, baicalein reduced the phosphorylation levels of PKCα and p38 proteins, which regulate invasion in poorly differentiated hepatoma cells. Finally, when SK-Hep1 cells were grown as xenografts in nude mice, intraperitoneal (i.p.) injection of baicalein induced a significant dose-dependent decrease in tumor growth. These results demonstrate the anticancer properties of baicalein, which include the inhibition of adhesion, invasion, migration, and proliferation of human hepatoma cells in vivo.