Kian Lam Lim

Flavokawain A Induces Apoptosis in MCF-7 and MDA-MB231 and Inhibits the Metastatic Process In Vitro

Introduction The kava-kava plant (Piper methsyticum) is traditionally known as the pacific elixir by the pacific islanders for its role in a wide range of biological activities. The extract of the roots of this plant contains a variety of interesting molecules including Flavokawain A and this molecule is known to have anti-cancer properties. Breast cancer is still one of the leading diagnosed cancers in women today. The metastatic process is also very pertinent in the progression of tumorigenesis. Methods MCF-7 and MDA-MB231 cells were treated with several concentrations of FKA. The apoptotic analysis was done through the MTT assay, BrdU assay, Annexin V analysis, cell cycle analysis, JC-1 mitochondrial dye, AO/PI dual staining, caspase 8/9 fluorometric assay, quantitative real time PCR and western blot. For the metastatic assays, the in vitro scratch assay, trans-well migration/invasion assay, HUVEC tube formation assay, ex vivo rat aortic ring assay, quantitative real time PCR and western blot were employed. Results We have investigated the effects of FKA on the apoptotic and metastatic process in two breast cancer cell lines. FKA induces apoptosis in both MCF-7 and MDA-MB231 in a dose dependent manner through the intrinsic mitochondrial pathway. Additionally, FKA selectively induces a G2/M arrest in the cell cycle machinery of MDA-MB231 and G1 arrest in MCF-7. This suggests that FKAs anti-cancer activity is dependent on the p53 status. Moreover, FKA also halted the migration and invasion process in MDA-MB231. The similar effects can be seen in the inhibition of the angiogenesis process as well. Conclusions FKA managed to induce apoptosis and inhibit the metastatic process in two breast cancer cell lines, in vitro. Overall, FKA may serve as a promising candidate in the search of a new anti-cancer drug especially in halting the metastatic process but further in vivo evidence is needed.

In vivo antitumor and antimetastatic effects of flavokawain B in 4T1 breast cancer cell-challenged mice

Flavokawain B (FKB) is a naturally occurring chalcone that can be isolated through the root extracts of the kava-kava plant (Piper methysticum). It can also be synthesized chemically to increase the yield. This compound is a promising candidate as a biological agent, as it is reported to be involved in a wide range of biological activities. Furthermore, FKB was reported to have antitumorigenic effects in several cancer cell lines in vitro. However, the in vivo antitumor effects of FKB have not been reported on yet. Breast cancer is one of the major causes of cancer-related deaths in the world today. Any potential treatment should not only impede the growth of the tumor, but also modulate the immune system efficiently and inhibit the formation of secondary tumors. As presented in our study, FKB induced apoptosis in 4T1 tumors in vivo, as evidenced by the terminal deoxynucleotidyl transferase dUTP nick end labeling and hematoxylin and eosin staining of the tumor. FKB also regulated the immune system by increasing both helper and cytolytic T-cell and natural killer cell populations. In addition, FKB also enhanced the levels of interleukin 2 and interferon gamma but suppressed interleukin 1B. Apart from that, FKB was also found to inhibit metastasis, as evaluated by clonogenic assay, bone marrow smearing assay, real-time polymerase chain reaction, Western blot, and proteome profiler analysis. All in all, FKB may serve as a promising anticancer agent, especially in treating breast cancer.

Flavokawain B induced cytotoxicity in two breast cancer cell lines, MCF-7 and MDA-MB231 and inhibited the metastatic potential of MDA-MB231 via the regulation of several tyrosine kinases In vitro.

BackgroundThe kava-kava plant (Piper methysticum) is traditionally consumed by the pacific islanders and has been linked to be involved in several biological activities. Flavokawain B is a unique chalcone, which can be found in the roots of the kava-kava plant. In this study, the operational mechanism of the anti-cancer activity of a synthetic Flavokawain B (FKB) on two breast cancer cell lines, MCF-7 and MDA-MB231 was investigated.MethodSeveral in vitro assays were attempted such as MTT, flow cytometry of cell cycle analysis, annexin V analysis, and JC-1 analysis to detect apoptosis. Moreover, in vitro metastasis assays were also performed such as transwell migration assay, invasion assay, rat aorta ring and HUVEC tube formation. Molecular analysis of related genes and proteins were conducted using real-time PCR and proteome profiler analysis.ResultsBased on our results, apoptosis was induced when both MCF-7 and MDA-MB231 were treated with FKB. A significant G2/M arrest was seen in MDA-MB231 cells. Additionally, FKB also inhibited the in vitro migration and invasion in MDA-MB231 cells in a dose dependent manner. Moreover, FKB can be a potential inhibitor in angiogenesis as it suppressed the formation of vessels in HUVEC cells as well as in the ex-vivo rat aortic ring assay.ConclusionOur findings suggested that FKB also regulated several receptor tyrosine kinases. Overall, FKB is not only a potential candidate to be an anti-cancer agent, but as an anti-metastatic agent as well.

Antibody and T cell responses induced in chickens immunized with avian influenza virus N1 and NP DNA vaccine with chicken IL-15 and IL-18.

We had examined the immunogenicity of a series of plasmid DNAs which include neuraminidase (NA) and nucleoprotein (NP) genes from avian influenza virus (AIV). The interleukin-15 (IL-15) and interleukin-18 (IL-18) as genetic adjuvants were used for immunization in combination with the N1 and NP AIV genes. In the first trial, 8 groups of chickens were established with 10 specific-pathogen-free (SPF) chickens per group while, in the second trial 7 SPF chickens per group were used. The overall N1 enzyme-linked immunosorbent assay (ELISA) titer in chickens immunized with the pDis/N1+pDis/IL-15 was higher compared to the chickens immunized with the pDis/N1 and this suggesting that chicken IL-15 could play a role in enhancing the humoral immune response. Besides that, the chickens that were immunized at 14-day-old (Trial 2) showed a higher N1 antibody titer compared to the chickens that were immunized at 1-day-old (Trial 1). Despite the delayed in NP antibody responses, the chickens co-administrated with IL-15 were able to induce earlier and higher antibody response compared to the pDis/NP and pDis/NP+pDis/IL-18 inoculated groups. The pDis/N1+pDis/IL-15 inoculated chickens also induced higher CD8+ T cells increase than the pDis/N1 group in both trials (P<0.05). The flow cytometry results from both trials demonstrated that the pDis/N1+pDis/IL-18 groups were able to induce CD4+ T cells higher than the pDis/N1 group (P<0.05). Meanwhile, pDis/N1+pDis/IL-18 group was able to induce CD8+ T cells higher than the pDis/N1 group (P<0.05) in Trial 2 only. In the present study, pDis/NP was not significant (P>0.05) in inducing CD4+ and CD8+ T cells when co-administered with the pDis/IL-18 in both trials in comparison to the pDis/NP. Our data suggest that the pDis/N1+pDis/IL-15 combination has the potential to be used as a DNA vaccine against AIV in chickens.

Synthesis of an anthraquinone derivative (DHAQC) and its effect on induction of G2/M arrest and apoptosis in breast cancer MCF-7 cell line

Anthraquinones are an important class of naturally occurring biologically active compounds. In this study, anthraquinone derivative 1,3-dihydroxy-9,10-anthraquinone-2- carboxylic acid (DHAQC) (2) was synthesized with 32% yield through the Friedel–Crafts condensation reaction. The mechanisms of cytotoxicity of DHAQC (2) in human breast cancer MCF-7 cells were further investigated. Results from the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that DHAQC (2) exhibited potential cytotoxicity and selectivity in the MCF-7 cell line, comparable with the naturally occurring anthraquinone damnacanthal. DHAQC (2) showed a slightly higher IC50 (inhibitory concentration with 50% cell viability) value in the MCF-7 cell line compared to damnacanthal, but it is more selective in terms of the ratio of IC50 on MCF-7 cells and normal MCF-10A cells. (selective index for DHAQC (2) was 2.3 and 1.7 for damnacanthal). The flow cytometry cell cycle analysis on the MCF-7 cell line treated with the IC50 dose of DHAQC (2) for 48 hours showed that DHAQC (2) arrested MCF-7 cell line at the G2/M phase in association with an inhibited expression of PLK1 genes. Western blot analysis also indicated that the DHAQC (2) increased BAX, p53, and cytochrome c levels in MCF-7 cells, which subsequently activated apoptosis as observed in annexin V/propidium iodide and cell cycle analyses. These results indicate that DHAQC (2) is a synthetic, cytotoxic, and selective anthraquinone, which is less toxic than the natural product damnacanthal, and which demonstrates potential in the induction of apoptosis in the breast cancer MCF-7 cell line.

Polyphenolic profiles and the in vivo antioxidant effect of nipa vinegar on paracetamol induced liver damage

Plant-based vinegar is proclaimed to have multiple health benefits due to the presence of polyphenol. However, not all vinegars have similar antioxidant activities. Nipa (Nypa fruticans) vinegar is one type of vinegar that has been widely consumed in Philippines and Malaysia. In this study, the antioxidant activity, polyphenolic acid profiles and antioxidant benefits to revert paracetamol-induced liver damage in mice in vivo have been evaluated. Nipa vinegar was found to contain antioxidant activity attributed to the presence of gallic acid, protocatechuic acid and 4-hydroxybenzoic acid. Continuous consumption of nipa vinegar for 14 days was able to recover the liver damage induced by paracetamol in a dosage dependent manner as indicated by the liver H&E histopathology, recovery serum liver profile (AST, ALT and ALP) and suppression of liver cytochrome P450 2E1 expression. These effects contributed to the antioxidant and anti-inflammatory effects of nipa vinegar. Similar to other types of vinegars, nipa vinegar, which is rich in polyphenolic acids, can contribute to in vivo anti-oxidation, anti-inflammation and liver protection effects in paracetamol treated mice.

Reprogramming cancer cells: overview & current progress

ABSTRACT Introduction: Cancer is a disease with genetic and epigenetic origins, and the possible effects of reprogramming cancer cells using the defined sets of transcription factors remain largely uninvestigated. In the handful of publications available so far, findings have shown that reprogramming cancer cells changed the characteristics of the cells to differ from the parental cancer cells. These findings indicated the possibility of utilizing reprogramming technology to create a disease model in the laboratory to be used in studying the molecular pathogenesis or for drug screening of a particular cancer model. Areas covered: Despite numerous methods employed in generating induced pluripotent stem cells (iPSCs) from cancer cells only a few studies have successfully reprogrammed malignant human cells. In this review we will provide an overview on i) methods to reprogram cancer cells, ii) characterization of the reprogrammed cancer cells, and iii) the differential effects of reprogramming on malignancy, epigenetics and response of the cancer cells to chemotherapeutic agents. Expert opinion: Continued technical progress in cancer cell reprogramming technology will be instrumental for more refined in vitro disease models and ultimately for the development of directed and personalized therapy for cancer patients in the future.

Artonin E induces p53-independent G1 cell cycle arrest and apoptosis through ROS-mediated mitochondrial pathway and livin suppression in MCF-7 cells

Artonin E is a prenylated flavonoid compound isolated from the stem bark of Artocarpus elasticus. This phytochemical has been previously reported to be drug-like with full compliance to Lipinski’s rule of five and good physicochemical properties when compared with 95% of orally available drugs. It has also been shown to possess unique medicinal properties that can be utilized in view of alleviating most human disease conditions. In this study, we investigated the cytotoxic mechanism of Artonin E in MCF-7 breast cancer cells, which has so far not been reported. In this context, Artonin E significantly suppressed the breast cancer cell’s viability while inducing apoptosis in a dose-dependent manner. This apoptosis induction was caspase dependent, and it is mediated mainly through the intrinsic pathway with the elevation of total reactive oxygen species. Gene and protein expression studies revealed significant upregulation of cytochrome c, Bax, caspases 7 and 9, and p21 in Artonin E-treated MCF-7 cells, while MAPK and cyclin D were downregulated. Livin, a member of the inhibitors of apoptosis, whose upregulation has been noted to precede chemotherapeutic resistance and apoptosis evasion was remarkably repressed. In all, Artonin E stood high as a potential agent in the treatment of breast cancer.

In Vivo Anti-Tumor Effects of Flavokawain A in 4T1 Breast Cancer Cell-Challenged Mice

Flavokawain A is a chalcone that can be found in the kava-kava plant (Piper methsyticum) extract. The kava-kava plant has been reported to possess anti-cancer, anti-inflammatory and antinociceptive activities. The state of the immune system, and the inflammatory process play vital roles in the progression of cancer. The immunomodulatary effects and the anti-inflammatory effects of flavokawain A in a breast cancer murine model have not been studied yet. Thus, this study aimed to elucidate the basic mechanism as to how flavokawain A regulates and enhance the immune system as well as impeding the inflammatory process in breast cancer-challenged mice. Based on our study, it is interesting to note that flavokawain A increased the T cell population; both Th1 cells and CTLs, aside from the natural killer cells. The levels of IFN-γ and IL-2 were also elevated in the serum of flavokawain A-treated mice. Apart from that, flavokawain A also decreased the weight and volume of the tumor, and managed to induce apoptosis in them. In terms of inflammation, flavokawain A-treated mice had reduced level of major pro-inflammatory mediators; NO, iNOS, NF-KB, ICAM and COX-2. Overall, flavokawain A has the potential to not only enhance antitumor immunity, but also prevents the inflammatory process in a cancer-prone microenvironment.

Flavokawain derivative FLS induced G2/M arrest and apoptosis on breast cancer MCF-7 cell line

Known as naturally occurring biologically active compounds, flavokawain A and B are the leading chalcones that possess anticancer properties. Another flavokawain derivative, (E)-1-(2′-Hydroxy-4′,6′-dimethoxyphenyl)-3-(4-methylthio)phenyl)prop-2-ene-1-one (FLS) was characterized with 1H-nuclear magnetic resonance, electron-impact mas spectrometry, infrared spectroscopy, and ultraviolet (1H NMR, EI-MS, IR, and UV) spectroscopic techniques. FLS cytotoxic efficacy against human cancer cells (MCF-7, MDA-MB-231, and MCF-10A) resulted in the reduction of IC50 values in a time- and dose-dependent mode with high specificity on MCF-7 (IC50 of 36 μM at 48 hours) against normal breast cell MCF-10A (no IC50 detected up to 180 μM at 72 hours). Light, scanning electron, and fluorescent microscopic analysis of MCF-7 cells treated with 36 μM of FLS displayed cell shrinkage, apoptotic body, and DNA fragmentation. Additionally, induction of G2/M cell arrest within 24 hours and apoptosis at subsequent time points was discovered via flow cytometry analysis. The roles of PLK-1, Wee-1, and phosphorylation of CDC-2 in G2/M arrest and proapoptotic factors (Bax, caspase 9, and p53) in promotion of apoptosis of FLS against MCF-7 cells were discovered using fluorometric, quantitative real-time polymerase chain reaction, and Western blot analysis. Interestingly, the presence of SCH3 (thiomethyl group) on ring B structure contributed to the selective cytotoxicity against MCF-7 cells compared to other chalcones, flavokawain A and B. Overall, our data suggest potential therapeutic value for flavokawain derivative FLS to be further developed as a new anticancer drug.