H9은 9가지 한약재를 혼합하여 에탄올로 추출한 추출물이다. 본 연구를 통하여 A549 인체 비소세포폐암 세포주에 대한 H9의 항암효과를 in vivo 조건에서 분석하였다. 실험에 사용할 동물모델은 athymic nude 마우스에 A549 세포를 이종이식하여 만들었다. 종양이 형성된 마우스들을 대조군, 폐암치료제 pemetrexed 투여군, H9 투여군, pemetrexed와 H9 투여군으로 나누어 약물을 투여하였다. 실험기간 동안 종양의 부피를 주기적으로 측정하여 각각의 약물에 의한 종양의 부피변화를 확인하였으며, 실험 종료 후에는 종양 및 기타 장기를 적출하여 암세포억제 관련인자들의 발현을 분석하였다. H9에 의해 Fas/FasL와 TNF-related apoptosis-inducing ligands (TRAIL)/death receptor 5 (DR5)와 같은 세포사멸 수용체의 발현은 증가 하였다. 미토콘드리아의 막 전위 붕괴에 관련된 Bcl-2와 Bcl-xL의 발현은 감소하였으며 caspase-3, caspase-8, caspase-9가 활성화되었다. 세포분열에 관련된 p-p53, p21, p27이 증가하였고, cyclin E, cyclin A, Ki-67, PCNA의 발현은 뿐만 아니라 세포생존에 관련된 p-Akt와 phosphatidylinositol-4, 5-bisphosphate 3-kinase (PI3K)의 발현도 감소하였다. 이러한 결과는 H9이 마우스에 이종이식한 A549 종양에 대한 외인성, 내인성 세포사멸 유도 및 성장을 억제시킨다는 것을 나타낸다. Trifolin은 생리활성을 갖는 플라보놀의 배당체이다. Trifolin은 항 진균 효과가 있다고 알려져 있으며, 항암효과에 대해서는 아직 연구가 되어있지 않다. 본 연구에서는 폐암에 대한 trifolin의 항암효과를 규명하기 위하여 NCI-H460 인체 비소세포폐암 세포주를 사용하여 연구를 하였다. Trifolin를 NCI-H460 세포에 처리하였으며 trifolin의 농도가 높아짐에 따라 외인성 세포사멸 수용체인 Fas/FasL/Fas associated protein with death domain (FADD)의 발현이 증가하였다. 미토콘드리아 막전위 붕괴를 통한 내인성 세포사멸에 관련된 Bax가 증가하였고, Bax의 작용을 억제하는 Bcl-2의 발현은 감소하였다. caspase-3, caspase-8, caspase-9의 활성화되었다. 세포생존에 관여하는 Akt/p-Akt의 발현은 감소시켰다. 반면 세포분열에 관련된 인자들은 발현에 큰 변화가 없었다. 본 연구를 통해 trifolin은 NCI-H460 비소세포폐암 세포에 대한 세포사멸 유도 및 세포생존 억제효과가 있다는 것을 확인하였다.
H9, a novel herbal extract, consisted of nine oriental medicinal herbs. H9 demonstrated cytotoxicity in A549 non-small cell lung cancer (NSCLC) cell lines. In this study, in order to investigate whether H9, and/or co-treatment with pemetrexed (PEM), one of anticancer drugs, could inhibit tumor growth in athymic nude mice models bearing A549 NSCLC cells. The mice were separated into groups and administered H9 and PEM for 2 weeks. Protein and mRNA levels were detected using western blotting and reverse transcription polymerase chain reaction (RT-PCR), respectively. Immunohistochemistry (IHC) was also performed on the tumor tissues. H9 induced cleavages of pro-apoptotic factors, such as caspase-3, caspase-8, caspase-9, and poly ADP-ribose polymerase (PARP). Expression levels of death receptors involving Fas/FasL, TNF-related apoptosis-inducing ligands (TRAIL), and DR5 were increased by H9 and co-treatment with PEM. Furthermore, analysis of levels of cell-cycle modulating proteins indicated that tumor cells were arrested in G1/S phase. In addition, phosphatidylinositol-4, 5-bisphosphate 3-kinase (PI3K)/Akt survival signaling pathways were inhibited by H9 and co-treatment with PEM. In conclusion, H9 and co-treatment with PEM inhibited tumor growth in athymic nude mice models bearing A549 NSCLC cells. Trifolin (kaempferol-3-O-galactoside) is a kind of flavonol conjugated with galactose. Trifolin is known to exhibit antifungal effects. However, the mechanism of its anticancer activity has not been studied yet. In this study, trifolin demonstrated anticancer effects in human lung cancer cells. Trifolin induced apoptosis in NCI-H460 human NSCLC cells by inhibiting survival pathway and inducting intrinsic and extrinsic apoptosis pathways. Trifolin decreased the Akt/p-Akt whereas there is no change in expression levels of PI3K, cyclin D1, cyclin E, and cyclin A. Trifolin initiated cytochrome c released by induction of mitochondrial outer membrane permeabilization (MOMP). Trifolin induced the increase of BCL-2-associated X protein (Bax) and decrease of Bcl-2. On the other hand, Bcl-xL expression level was not altered. Trifolin increased death receptor involving Fas/Fas ligand and Fas-associated protein with death domain (FADD). Consequently, trifolin led to the activation of caspase-3, caspase-8, caspase-9 and proteolytic cleavage of PARP. In conclusion, trifolin induced apoptosis via death receptor-dependent and mitochondria-dependent pathways. These findings suggest that trifolin has potentials to become therapeutic agent for human lung cancer.
1. Introduction 11.1. Lung cancer 11.2. H9 31.3. Trifolin 61.4. Apoptosis 71.5. Cell cycle and proliferation 81.6. Animal experiment 92. Materials and methods 102.1. Reagents and antibodies. 102.2. Preparation of H9 102.3. Cell cultures 112.4. Cell viability assay 112.4.1. Trypan blue assay 112.4.2. MTS assay 122.5. RNA extraction and mRNA expression analysis 122.6. Western blot analysis 132.7. Experimental xenograft animal model 142.8. Tumor growth inhibition assay 142.9. Immunohistochemistry (IHC) 152.10. Cell cycle analysis 162.11. Analysis of mitochondrial outer membrane permeabilization 163. Results 183.1. H9 inhibits tumor growth and induces apoptosis via intrinsic and extrinsic signaling pathway in human non-small cell lung cancer xenografts 183.1.1. H9 and co-treatment with PEM suppressed cell viability 183.1.2. H9 inhibited tumor growth in the in vivo xenograft model 203.1.3. H9 and PEM did not show toxicity in the in vivo experiment 223.1.4. H9 induced intrinsic and extrinsic pathway mediated via caspase activation 243.1.5. H9 enhanced PEM induced cell cycle arrest 263.1.6. H9 inhibited PI3K/Akt cell survival factors 283.1.7. Discussion 303.2. Trifolin induces apoptosis via extrinsic and intrinsic pathways in the NCI-H460 human NSCLC cell line 343.2.1. Growth inhibitory effect of trifolin in human NSCLC NCI-H460 cells 343.2.2. Sub-G1 accumulation and down regulation of survival pathway by trifolin 363.2.3. Trifolin induces chromatin condensation, DNA fragmentation and cytoplasm shrinkage 383.2.4. Trifolin induces apoptosis via p53 mediated mitochondrial outer membrane permeabilization 403.2.5. Trifolin induce apoptosis via extrinsic pathway 423.2.6. Discussion 44References 47Abstract (in Korean) 57