Multi-walled carbon nanotubes (MWNTs) are suitable for delivering large biomolecules with lower cytotoxicity values and low prime cost. Surface modifications of MWNTs affect interaction with cells and proteins. Oxidation with strong acids decreases cytotoxicity of CNTs and increases protein-loading capacity. Here, after oxidation, TEM images revealed more aligned structure and carboxylated groups at the surface which decreases toxicity. Functionalized MWNTs showed more gradual degradation than the pristine MWNTs and mass loss increased by 2% in the same temperature range. Raman spectroscopy corrected graphitic structure with characteristic D and G bands at 1330 and 1579 cm−1 and increased intensity after oxidation. FTIR spectroscopy peaks at 1443 cm−1, 1560, 1640 cm−1, 2100–2200 cm−1 and 3426 cm−1 are ascribed to C–O–C vibrational stretch, C=C bonds, vibration of C≡C bonds and stretch of hydroxyl groups, respectively. The sonicationdriven dispersion of in phosphate-buffered saline, distilled water and cell culture medium were detected by UV–vis–NIR spectroscopy, water-dispersed functionalized MWNTs revealed the highest absorbance value. Cytotoxicity of MWNTs was investigated before and after functionalization in breast cancer (MDA-MB-231) and human vein endothelial (HUVEC) cells. Relatively low-toxicity results were obtained in functionalized MWNTs and cellular uptake of MWNTs were corrected with fluorescent imaging of cells and cell lysates. Protein-loading capacity of fsMWNTs (functionalized short-length multi-walled carbon nanotubes) was evaluated by using bovine serum albumin (BSA) and with an equal amount of fsMWNTs and BSA; 36% binding yield was obtained. Protein corona after covalent functionalization potentially lowered cytotoxicity up to 6%.
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.
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.
Nelumbo nucifera Gaertn.(family Nymphaeaceae) has been used for summer heat syndrome as home remedy in Japan, China and Korea. Although whole plant parts are edible, root is commonly consumed. It has been reported that rhizome extract showed anti-diabetic and anti-inflammatory effects. However, in spite of usefulness for treatment of various diseases, the effect of Nelumbo nucifera rhizome(NNR) on proliferation, migration and matrix degrading enzymes-matrix metalloproteinsases(MMPs), the expression of which degrades extracellular matrix(ECM) leading to metastasis, has not been fully elucidated. We examined the effect of hot water extract of NNR on the proliferation, migration and secretion of MMP-2 and MMP-9 in rat smooth muscle cells(rSMC), epidermoid cancer cells(A431) and breast cancer cells(MDA-MB-231). The proliferation assay was carried out using MTT assay, the principle of which depends upon the conversion of MTT by mitochondrial dehydrogensases of viable cells to formazan crystals. The effect of NNR on migration of cells was examined using wound healing assay. Our results showed that there was inhibition in the proliferation, migration and expression of MMP-2 and MMP-9 in dose dependent fashion in all the cells used. Thus, we concluded that NNR could be used as traditional medicine in the treatment of various diseases where proliferation, migration and MMPs' expression plays a pathological role like in restenosis and metastasis.