Our objective of this study is to design and develop a polyethylene glycol ( PEG2000)-modified multiwall carbon nanotube (PEGylated MWCNT) formulation for oral controlled metronomic chemotherapeutic drug delivery. Multiwall carbon nanotubes undergo various chemical modifications including oxidation with strong acids, conjugation of polyethylene glycol, and coating with cellulose acetate phthalate which resulted in the formation of aqueous dispersion and prevention of drug degradation in acidic environment. Advanced analytical procedure such as Fourier transform infra-red, X-ray diffraction, differential scanning calorimetry, thermal gravimetric analysis, transmission electron microscopy, and dynamic light scattering techniques were used to evaluate physicochemical characterization. We also performed in vitro cytotoxic study by MTT assay and results revealed that carboplatin-loaded PEGylated MWCNTs did not show significant detrimental effect on the viability of MDA-MB-231 (human breast cancer) cells. The maximum encapsulation and drug-loading capacity were determined to be 71.58 ± 0.04 and 39.62 ± 0.07%, respectively. The release of carboplatin from PEGylated MWCNTs was investigated at simulated intestinal fluid (SIF), pH 6.8, after optimizing at simulated gastric fluid (SGF), pH 1.2, by enteric coating. Enteric-coated PEGylated MWCNTs exhibit pH-responsive drug activity in a sustained manner especially at pH 6.8. This surface modification strongly suggests that PEGylated MWCNTs could be a potential carrier for metronomic chemotherapeutic agent for high drug resistance, drug with maximum adverse effect and poorly oral bioavailable drugs.

After being subjected to different cooking methods, small black beans (Rhynchosia nulubilis) were investigated in order to assess the effects of the retained bioactive compounds. Using uncooked, pan broiled, boiled, steamed, and pressure cooked beans, the inhibitory effects of MCF-7 cell migration were evaluated at protein concentrations of 40, 160, and 640 μm/mL, using the Boyden's chamber assay. All protein concentrations (40, 160, and 640 μm/mL) of pan broiled beans showed significant reduction (59.83, 32.48, and 21.37%, respectively) in the rate of cell migration to the lower chambers (p-value less than 0.001). Estimated cell migration rates correlated to the exponential decay between experimentally measured cell migration rates and converted samples. The range of estimated cell migration rate for each 100 mg/mL of cooked sample was as follows: pan broiled (21.16%), boiled (22.48%), steamed (22.48%), pressure cooked (29.52%), and uncooked (35.03%) beans. Our study indicated that selective modifications of cooking methods for small black beans, such as pan broiling, ameliorated the inhibitory effects of MCF-7 cell migration. This suggests that optimized cooking methods increase the nutritional contents of the cooked food.

6-Gingerol exerts anti-tumor effects in various cancer cell models. We evaluated the effect of 6-gingerol on the growth of MCF-7 breast cancer cells and MCF-10A breast epithelial cells to determine whether any growth-inhibitory effects found were attributable to apoptosis, and to elucidate the underlying mechanism of action. 6-Gingerol inhibited the viability of both cell lines in a dose- and time-dependent manner; however, the degree of inhibition was greater in MCF-7 than MCF-10A cells. By flow cytometry, induction of dose- and time-dependent apoptosis was found, and the magnitude of apoptosis was also markedly greater in MCF-7 than MCF-10A cells. Expression of caspase-3 and poly (ADP-ribose) polymerase (PARP) was observed in MCF-7 cells treated with 6-gingerol, and further cleavage of PARP occurred in these cells. We suggest that 6-gingerol induces apoptosis in human breast cancer cells mainly by promoting caspase-3 expression and subsequent degradation of PARP.

본 연구는 인체 유래 유방암세포인 MDA-MB-231 세포 증식을 억제하고 세포사멸을 유도하는 천연소재 발굴을 목적으로, 북한산 두릅 추출물을 MDA-MB-231 세포에 처리하여 세포사멸 및 작용기전을 규명하였다. 실험 결과, 두릅 추출물 처리 농도가 증가할수록 세포증식이 감소하였고, 세포질의 응축과 핵이 분절되는 등 apoptotic bodies를 형성하였다. 또한 유세포 분석기를 사용하여 MDA-MB-231의 세포주기가 억제되었고, 세포사멸의 특징인 sub-G1 수치가 증가되는 것이 관찰되었고, 두릅 추출물 농도가 증가함에 따라 apoptotic 세포가 유의적으로 증가하였으며, 특히 early apoptosis 보다 late apoptosis가 더 많이 진행됨을 확인할 수 있었다. 이를 바탕으로 MDA-MB-231 세포사멸과 관련된 유전자를 확인하고자 RT-PCR과 western blotting을 수행한 결과, 세포사멸의 주요한 조절인자인 anti-apoptotic인 bcl-2 발현이 두릅 추출물 처리 시 농도 의존적으로 감소되었고, 반대로 Bax의 발현은 증가됨을 확인하였다. 이를 통해 불활성화 형태로 존재한 pro-caspase-9과 pro-caspase-3의 발현이 시료 농도가 증가할수록 감소되었고, 활성화된 형태인 cleaved caspase-9과 cleaved caspase-3의 발현은 두릅 추출물 처리 농도에 의존적으로 증가하였다. 뿐만 아니라, 세포 사멸 과정의 주요 인자인 PARP 또한 시료 농도가 증가할수록 절단 현상이 비례적으로 증가하였다. 이상의 실험 결과를 근거로, 북한산 두릅 지상부의 70% ethyl alcohol 추출물이 MDA-MB-231 인체 유방암 세포의 증식을 억제하는 효과가 있음을 확인하였고, 세포사멸과 관련된 활성기전을 규명하였다. 추후 암 예방/치료제로서 두릅을 활용하기 위해서는 활성 본체와 안정성 규명 및 임상실험 등 추가 연구가 필요할 것으로 사료된다.

Endocrine disrupting chemicals (EDCs) have detrimental effects on human health. Among these EDCs, bisphenol A (BPA) binds to estrogen receptors (ERs) to stimulate estrogen-mediated responses. BPA is assumed to disrupt the reproductive and developmental system of humans. In addition, BPA has recently been suspected as a risk of carcinogenesis. Because BPA can cause abnormal estrogen-mediated response in the organism, exposure to BPA may stimulate growth of estrogen-dependent breast cancers in human. In breast cancer, cyclin E and cyclin-dependent kinase inhibitor p27 are important in G1/S phase transition during cell cycle progression. In this study, using an MTT assay, we investigated the effect of BPA on proliferation of MCF-7 breast cancer cells in vitro. In addition, we also analyzed the transcriptional levels of cyclin E and p27 following treatment with BPA using semi-quantitative RT-PCR. As a result, treatment with BPA resulted in significant induction of breast cancer cell growth, compared to a vehicle. BPA caused alterations of cyclin E and p27 mRNA expression. Expression of cyclin E was increased by BPA, while p27 was decreased at 24 h after treatment with BPA in MCF-7 breast cancer cells. Taken together, these collective results suggest that exposure to BPA induced breast cancer cell proliferation with deregulation of the cell cycle. A further study is required in order to determine the effects of BPA on the carcinogenic process in in vivo models.

Cordyceps militarisis well known as a traditional herbal ingredient, which has been used for patients suffering from cancer in oriental medicine. In this study we have investigated the biochemical mechanisms of anti-proliferative effects by C. militarisextract(CME) in human breast cancer MDA-MB-231 cells. It was found that CME treatment induced chromatin condensation, mitochondrial energization, annexin V staining and sub-G1 phase DNAcontent. These indicators of apoptosis correlate with the mitochondrial dependent pathway, which results in the activation of caspase-3 activity. Both the cytotoxic effect by CME treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor,demonstrating the important role of caspase-3 in the observed cytotoxic effect. Cotreatment of CME and LY294002, resulted in significantly induction of apoptosis. These results indicate that caspase-3 is a key regulator of apoptosis in response to CME in human breast cancer MDAMB- 231 through downregulation of Akt, and that the C. militaris extract may therefore have therapeutic potential against human breast cancer.

Cordyceps militaris is well known as a traditional herbal ingredient, which has been used for patients suffering from cancer in oriental medicine. In this study we have investigated the biochemical mechanisms of anti-proliferative effects by C. militaris extract(CBE) in human breast cancer MDA-MB-231 cells. It was found that CBE treatment induced chromatin condensation, mitochondrial energization, annexin V staining and sub-G1 phase DNA content. These indicators of apoptosis correlate with the mitochondrial dependent pathway, which results in the activation of caspase-3 activity. Both the cytotoxic effect by CBE treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, demonstrating the important role of caspase-3 in the observed cytotoxic effect. Co-treatment of CBE and LY294002, resulted in significantly induction of apoptosis. These results indicate that caspase-3 is a key regulator of apoptosis in response to CBE in human breast cancer MDA-MB-231 through down regulation of Akt, and that the C. militaris extract may therefore have therapeutic potential against human breast cancer.

Cordyceps militaris is well known as a traditional herbal ingredient, which has been used for patients suffering from cancer in oriental medicine. In this study we have investigated the biochemical mechanisms of anti-proliferative effects by C. militaris extract(CBE) in human breast cancer MDA-MB-231 cells. It was found that CBE treatment induced chromatin condensation, mitochondrial energization, annexin V staining and sub-G1 phase DNA content. These indicators of apoptosis correlate with the mitochondrial dependent pathway, which results in the activation of caspase-3 activity. Both the cytotoxic effect by CBE treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, demonstrating the important role of caspase-3 in the observed cytotoxic effect. Co-treatment of CBE and LY294002, resulted in significantly induction of apoptosis. These results indicate that caspase-3 is a key regulator of apoptosis in response to CBE in human breast cancer MDA-MB-231 through down regulation of Akt, and that the C. militaris extract may therefore have therapeutic potential against human breast cancer.

약용식물내 에스트로겐성과 항-에스트로겐성을 조사하고 항암인자를 발견하기 위하여, 본연구는 에탄올추출로 제조된 9종류의 한국산 약용식물에 대하여 재조합효모와 MCF-7 사람유방암세포주를 이용하여 스크리닝하고 비교하였다. 재조합효모를 이용한 실험결과, 7종류의 약용식물에서 에스트로겐성이 나타났고, 4종류에서 안드로겐성이 나타났다. 또한 MCF-7 사람유방암세포주를 이용한 실험결과, 8종류의 추출물이 MCF-7 세포의 성장을 억제하는 것으로 확인되었으며 비스페놀 A와 동시 처치한 경우에도 유의적으로 억제하는 것으로 나타났다. 또한 Clyeyrrhiza uralensis, Cassia tora, Syringa velutina, Zingiber officinale, Malva verticillata, Panax ginseng C.A. Meyer는 식물성 에스트로겐으로서 에스트로겐에 양성인 사람유방암세포의 증식을 유의적으로 억제시티는 흥미로운 결과가 제시되었다. 따라서 이번 연구는 한국산 약용식물이 식물성 에스트로겐과 항암인자로서 이용될 수 있으며, 에스트로겐의 활성을 조사하는데 유용하게 이용될 수 있을 것으로 사료된다.

Iris nertschinsk has been used generally as a decorative plant. However, it has been almost used as a medicine for therapy on various human diseases. In this study, we demonstrate the anti-tumor effect of Iris nertschinsk on human breast cancer cells. Firstly, we found that Iris nertschinsk dose-dependently induced cell death in human breast cancer cell lines, MCF7 and MDA-MB231. Moreover, phosphorylation of p53 was induced after Iris nertschinsk treatment in MCF7 cells, which has a functional p53, but not in MDA-MB231 cells, which has a dysfunctional p53. We next examined whether Iris nertschinsk induces caspase-dependent cell death. Caspase-7 was cleaved after Iris nertschinsk treatment in MCF7 cells. Interestingly, either caspase-3 or caspase-7 was cleaved in MDA-MB231 cells that p53 had been phosphorylated by Iris nertschinsk treatment, indicating that Iris nertschinsk induces apoptosis through the cleavage of caspase-3, -7 in human breast cancer cell lines, MCF7 and MDA-MB231, but related to the status of p53. Therefore, these results suggest that Iris nertschinsk could be used as a treatment for human breast cancer. This research is supported by National Institute of Agricultural Biotechnology research grant.