Recently, the area of marine resources has become concerned with sources for the next generation of the bio-industry. Until present, development of the marine resources has remained limited, although a large number of these resources are considered to have potential for various significant biological activities. Most marine sponges, marine algae and coral could be used to create specific compounds for survival against a harsh environment. Therefore, it was necessary that these materials needed to be elucidated with biological activities, such as like anti-inflammatory, anti-viral or anti-cancer effects for their utilization in the bio-industry. In this study, we screened extracts of marine resources for their anti-cancer effect on human colorectal cancer cells. These resources were collected at Kosrae of Micronesia on April, 2013 and extracted with methanol. Cytotoxicity of marine resources was observed. Of a total of 20 specimens, three specimens dose-dependently demonstration inhibition of cell viability. Furthermore, cells treated with these specimens for 48h were induced p53, p21, Bax and caspase-3. The results suggest that they involved p53-mediated apoptosis. Two positive specimens (1304KO-327 and 1304KO-329) were verified as the identical materials, which are Hyrtios sp. Unfortunately 1304KO-207 was not yet classified and needed to identify in the further study. There results suggested that marine resources with positive potential in anticancer effect would be good candidates as useful bio-resources.

The antigen GA733 is a cell-surface highly expressed glycoprotein on most human colorectal carcinomas. GA733 can be characterized as a cancer vaccine. In this study, GA733 was fused to the human immunoglobulin IgG Fc fragment to become recombinant gene GA733-Fc. Based on this, 4 recombinant genes were constructed as follows: GA733-Fc with signal peptide sequence and fusion of ER retention sequence (KDEL) (spGA733-FcK), GA733-Fc with signal sequence (spGA733-Fc), GA733-Fc fused to ER retention sequence (GA733-FcK) without signal peptide and GA733-Fc without signal peptide. Baculovirus-insect cell expression system is widely used for the high level production of recombinant proteins especially for glycoproteins. Constructed 4 recombinant genes were cloned to baculovirus express vectors. DH10Bac E.coli.-mediated transformation was used to generate recombinant bacmid DNA. Recombinant DNA was confirmed by PCR. Insect cell was transfected by bacmid to produce the recombinant baculovirus infects insect cell to produce recombinant protein. Western blot and sandwich ELISA showed the expression of recombinant proteins. Each cell lines (sf9 and HighFive) differed in recombinant proteins production level and protein secretion capability. N-Glycosylation analysis showed the function of signal peptide and ER retention sequence (KDEL). Taken together, baculovirus-insect cell system can be used to express recombinant GA733-Fc glycoproteins.

본 연구 결과들을 바탕으로 도깨비부채 잎(RPL)은 GSK3β 활 성화를 통해 IκB-α를 인산화시켜 단백질 분해를 유도하고 Iκ B-α 분해로 인해 p65 핵내 전이를 유도하여 NF-κB 신호전달을 활성화?시킨다. 이러한 NF-κB 신호전달 활성화를 통해 대장암 의 세포생육을 억제하는 것으로 추정된다. 본 결과는 도깨비부채 잎을 소재로 항암을 목적으로 한 천연치료제 및 대체보완소재 개발에 활용할 수 있다고 판단된다. 그러나 도깨비부채 잎의 대장암에 대한 세포생육 억제와 작용기전의 정확한 관련성과 세포생육 억제활성 물질 분석을 위해 추가적인 연구가 필요할 것으로 사료된다.

이상의 연구 결과로 미루어 볼 때, 댕댕이나무 잎과 가지 추추출물은 대장암 세포주 HCT116과 SW480세포의 생육을 억제 하였으나 열매추출물은 억제활성이 나타나지 않았다. 잎과 가지 추출물은 cell migration과 wound healing assay를 통해 비정상적인 세포증식 억제를 확인하였으며, β-catenin과 TCF4 의 단백질 수준을 감소시켜 비정상적인 Wnt 신호전달을 억제를 통해 대장암세포의 생육을 억제하는 것으로 판단된다. 따라서 댕댕이나무 잎과 가지는 항암을 위한 대체보완소재 및 천연 항암제 개발을 위한 소재로 활용이 가능할 것으로 판단된다.

Potassium cyanate는 무기화합물로 단백질의 번역 후 과정에서 카바밀화(carbamylation)을 유도할 수 있고 이러한 카바밀화 반응은 다양한 질병 및 조건에서 세포의 사멸과 관련이 있다. 이전 연구결과에서 KCN은 사람 대장암 세포주인 HCT 116세포의 방사선 감수성을 향상시키는 것을 확인하였지만 그 기전을 명확히 규명하기에는 많이 부족한 실정이다. 본 연구에서는 방사선에 다소 저항성을 가지는 대장암 세포에서 KCN이 방사선 감수성을 향상시키고 세포사멸 시키는 기전을 확인하기 위해 2 mM의 KCN 처리 후 저 선량의 광자선을 조사하여 세포주기, 세포 생존율, 세포 사멸 관련 단백질(caspase-1, PARP) 발현량, TNF-α 분비 및 TNF-α 관련 전사인자(NF-κB)의 연관성을 확인하였다. 그 결과 KCN 처리 후 광자선을 조사한 세포에서 cas pase-3 및 PARP의 활성이 증가하고 이는 세포주기의 정지와 세포사멸을 유도하였다. 또한 이 과정에서 DN A 전사인자인 NF-κB에 의해 세포 외로 TNF-α를 지속적으로 분비하여 세포사멸에 관여함을 확인하였다. 이러한 결과들을 토대로 KCN이 radiosensitizer로서 작용할 수 있는 가능성이 있다고 사료된다.

Patients with type II diabetes mellitus are more susceptible to colorectal cancer (CRC) incidence than non-diabetics. The anti-diabetic drug metformin is most commonly prescribed for the treatment of this disease and has recently shown antitumor effect in preclinical studies. The aberrant mutational activation in the components of RAS/RAF/MEK/ERK and PI3K/AKT/mTOR signaling pathway is very frequently observed in CRC. We previously reported that metformin inhibits the phosphorylation of ERK and BEZ235, a dual inhibitor of PI3K and mTOR, has anti-tumor activity against HCT15 CRC cells harboring mutations of KRAS and PIK3CA. Therefore, we hypothesized that simultaneous inhibition of two pathways by combining metformin with BEZ235 could be more effective in the suppression of proliferation than single agent treatment in HCT15 CRC cells. Here, we investigated the combinatory effect of metformin and BEZ235 on the cell survival in HCT15 CRC cells. Our study shows that both of the two signaling pathways can be blocked by this combinational strategy: metformin suppressed both pathways by inhibiting the phosphorylation of ERK, 4E-BP1 and S6, and BEZ235 suppressed PI3K/AKT/ mTOR pathway by reducing the phosphorylation of 4E-BP1 and S6. This combination treatment synergistically reduced cell viability. The combination index (CI) values ranged from 0.44 to 0.88, indicating synergism for the combination. These results offer a preclinical rationale for the potential therapeutic option for the treatment of CRC.

Background: Inula japonica Thunb. is a plant belonging to the family compositae. Inulae flos (flower of I. britannica var. chinensis Regal.) is the dried flower of I. japonica Thunb. and contains various flavonoids (patulitrin, nepitrin and kaempferol), which have been utilized in traditional oriental medicine to treat nausea, phlegm, and coughs. However, ethanol extract of I. britannica (IJE) has not been previously studied for its use in cancer treatment, and its effects on oxidative stress, or inflammation. Thus, the present study investigated the anti-oxidant, anti-inflammatory, and anti-colorectal cancer effects of IJE using RAW264.7 and HCT- 116 cells, which are human colorectal cancer cell line. Methods and Results: IJE contained flavonoids (80.95 ± 5.3 ㎎/g) and polyphenols (310.53 ± 10.6 ㎎/g). Moreover, it reduced lipopolysaccharide (LPS)-induced nitric oxide (NO) production and H2O2-induced oxidative stress by decreasing reactive oxygen species (ROS) levels. Additionally, the 500 ㎍/㎖ IJE treatment increased caspase-3 activity and apoptotic cell death in HCT-116 cells. Conclusions: These results demonstrate that the anti-cancer effect of IJE against human colorectal cancer cells involves caspase-3 activation and apoptotic cell death. IJE also inhibited LPS-induced NO production, and H2O2-induced oxidative stress in RAW264.7 cells. However, further studies are required to explore how IJE treatment regulates signal transduction in NO and ROS production.

In this study, we elucidated the molecular mechanism of silymarin by which silymarin may inhibits cell proliferation in human colorectal cancer cells in order to search the new potential anti-cancer target associated with the cell growth arrest. Silymarin reduced the level of c-Myc protein but not mRNA level indicating that silymarin-mediated downregulation of c-Myc may result from the proteasomal degradation. In the confirmation of silymarin-mediated c-Myc degradation, MG132 as a proteasome inhibitor attenuated c-Myc degradation by silymarin. In addition, silymarin phosphorylated the threonine-58 (Thr58) of c-Myc and the point mutation of Thr58 to alanine blocked its degradation by silymarin, which indicates that Thr58 phosphorylation may be an important modification for silymarin-mediated c-Myc degradation. We observed that the inhibition of ERK1/2, p38 and GSK3β blocked the Thr58 phosphorylation and subsequent c-Myc degradation by silymarin. Finally, the point mutation of Thr58 to alanine attenuated silymarin-mediated inhibition of the cell growth. The results suggest that silymarin induces the cell growth arrest through c-Myc proteasomal degradation via ERK1/2, p38 and GSK3β-dependent Thr58 phosphorylation.