• Biomolecules & Therapeutics
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• 제28권6호
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• pp.561-568
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• 2020

We examined the anticancer effects of a novel sirtuin inhibitor, MHY2256, on HCT116 human colorectal cancer cells to investigate its underlying molecular mechanisms. MHY2256 significantly suppressed the activity of sirtuin 1 and expression levels of sirtuin 1/2 and stimulated acetylation of forkhead box O1, which is a target protein of sirtuin 1. Treatment with MHY2256 inhibited the growth of the HCT116 (TP53 wild-type), HT-29 (TP53 mutant), and DLD-1 (TP53 mutant) human colorectal cancer cell lines. In addition, MHY2256 induced G0/G1 phase arrest of the cell cycle progression, which was accompanied by the reduction of cyclin D1 and cyclin E and the decrease of cyclin-dependent kinase 2, cyclin-dependent kinase 4, cyclin-dependent kinase 6, phosphorylated retinoblastoma protein, and E2F transcription factor 1. Apoptosis induction was shown by DNA fragmentation and increase in late apoptosis, which were detected using flow cytometric analysis. MHY2256 downregulated expression levels of procaspase-8, -9, and -3 and led to subsequent poly(ADP-ribose) polymerase cleavage. MHY2256-induced apoptosis was involved in the activation of caspase-8, -9, and -3 and was prevented by pretreatment with Z-VAD-FMK, a pan-caspase inhibitor. Furthermore, the autophagic effects of MHY2256 were observed as cytoplasmic vacuolation, green fluorescent protein-light-chain 3 punctate dots, accumulation of acidic vesicular organelles, and upregulated expression level of light-chain 3-II. Taken together, these results suggest that MHY2256 could be a potential novel sirtuin inhibitor for the chemoprevention or treatment of colorectal cancer or both.

• BMB Reports
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• 제41권3호
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• pp.210-216
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• 2008

CSE1L/CAS, a microtubule-associated, cellular apoptosis susceptibility protein, is highly expressed in various cancers. Microtubules are the target of paclitaxel-induced apoptosis. We studied the effects of increased or reduced CAS expression on cancer cell apoptosis induced by chemotherapeutic drugs including paclitaxel. Our results showed that CAS overexpression enhanced apoptosis induced by doxorubicin, 5-fluorour-acil, cisplatin, and tamoxifen, but inhibited paclitaxel-induced apoptosis of cancer cells. Reductions in CAS produced opposite results. CAS overexpression enhanced p53 accumulation induced by doxorubicin, 5-fluorouracil, cisplatin, tamoxifen, and etoposide. CAS was associated with $\alpha$-tubulin and $\beta$-tubulin and enhanced the association between $\alpha$-tubulin and $\beta$-tubulin. Paclitaxel can induce G2/M phase cell cycle arrest and microtubule aster formation during apoptosis induction, but CAS overexpression reduced paclitaxel-induced G2/M phase cell cycle arrest and microtubule aster formation. Our results indicate that CAS may play an important role in regulating the cytotoxicities of chemotherapeutic drugs used in cancer chemotherapy against cancer cells.

• ALGAE
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• 제33권2호
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• pp.191-203
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• 2018

Fragilariopsis cylindrus is one of the most successful psychrophiles in the Southern Ocean. To investigate the molecular mechanism of biomineralization in this species, we attempted to synchronize F. cylindrus growth, since new cell wall formation is tightly coupled to the cell division process. Nutrient limitation analysis showed that F. cylindrus cultures rapidly stopped growing when deprived of silicate or light, while growth continued to a certain extent in the absence of nitrate. Flow cytometry analysis indicated that deprivation of either silicate or light could effectively arrest the cell cycle of this diatom species at the G1 phase, suggesting that synchrony can be established using either factor. Fluorescence labeling of new cell walls was faintly detectable as early as approximately 6 h after silicon repletion or light irradiation, and labeling was markedly intensified by 18 h. It is revealed that the synthesis of girdle bands begins before valve synthesis in this species, with active valve synthesis occurring during the G2 / M phase. Expression profiling revealed that selective member(s) of the F. cylindrus SIT genes (FcSIT) respond to silicate and light, with a different set of genes being responsive to each factor. The Si / light double depletion experiments demonstrated that expression of one FcSIT gene is possibly correlated to transition to G2 / M phase of the cell cycle, when the valve is actively formed.

• Journal of Microbiology and Biotechnology
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• 제30권6호
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• pp.893-902
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• 2020

Propolis is a resinous substance that is collected by Apis mellifera from plant sources and is used in traditional medicine. To study the phytochemical constituents and apoptotic potential of Jordanian propolis extract against different cancer cell lines, propolis was extracted using methanol, hexane, and ethyl acetate and was fractionated using chromatographic methods. Cytotoxicity was assessed using MTT and LDH assays. The apoptotic potential was investigated using florescence microscopy, multicaspase assay, Annexin-V and dead cell assay, and cell cycle assay. The phytochemical constituents were analyzed using GC-MS. The methanol extract of propolis exhibited cytotoxic potential against all cell lines tested. The IC₅₀ values of the methanol extract were 47.4, 77.8, 91.2, and 145.0 ㎍/ml for HepG2, LoVo, MDAMB231, and MCF7 cell lines, respectively. The IC₅₀ values of the F1 fraction were 31.6 (MDAMB231), 38.9 (HepG2), 36.7 (LoVo) and 75.5 (MCF7) ㎍/ml. On further purification using thin-layer chromatography, the IC₅₀ values of the F1-3 fraction were found to be 84.31(HepG2), 79.2 (MCF7), 70.4 (LoVo), and 68.9 (MDAMB231) ㎍/ml, respectively. The anticancer potential of the F1 fraction was confirmed through the induction of apoptosis and cell cycle arrest at the G0/G1 phase. The GC-MS analysis of the F1 fraction revealed the presence of 3-methyl-4-isopropylphenol (29.44%) as a major constituent. These findings indicate the potential of propolis extract as a cancer therapy. However, further investigation is required to assess the acute and subacute toxicity of the most active fraction.

• Journal of Microbiology and Biotechnology
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• 제24권3호
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• pp.346-353
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• 2014

The chlorophyll-related compound pheophorbide a (Pa) was successively purified from an edible red seaweed, Grateloupia elliptica, using silica, octadecyl silica column chromatography and reversed phase-high-performance liquid chromatography, as well as the cell cycle inhibitory and apoptotic effects of Pa being investigated in U87MG glioblastoma cells. The Pa exhibited strong anticancer effects in the absence of direct photo-irradiation against various cancer cell lines, including U87MG, SK-OV-3, and HeLa cells. Among the cancer cells, the strongest anticancer activity of Pa exhibited on U87MG cells with $IC_{50}$ values of 2.8 ${\mu}g/ml$. In addition, Pa specifically had cytostatic activity on glioblastoma cells rather than human umbilical vein endothelial cells. Analysis of the cell cycle distribution showed that Pa induced G0/G1 arrest of U87 MG cells. In addition, arrested cells induced late apoptosis and DNA degradation under dark condition. These results suggest that Pa isolated from G. elliptica is a potential glioblastoma-specific anticancer agent without side effects on normal cells.

• 대한임상검사과학회지
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• 제56권1호
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• pp.73-84
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• 2024

펄스 전자기장(pulsed electromagnetic field, PEMF)은 여러 항암제의 항암 효과를 향상시키는 것으로 알려져 있고 독소루비신(doxorubicin, DOX)은 유방암을 포함한 다양한 종류의 악성 종양을 치료하는 데 사용되는 항암제이다. 본 연구는 PEMF가 MCF-7 유방암 세포에 대한 DOX의 항암 효과 증진 여부를 조사하고 관련기전을 규명하기 위해 진행되었다. 본 연구팀은 DOX와 PEMF를 동시에 처리하면 DOX 단독 처리에 비해 MCF-7 유방암 세포의 생존율 감소가 더 커지는 것을 확인하였다. PEMF는 cyclin-dependent kinase 2의 인산화와 p53, p21, 사이클린 E2 및 polo like kinase 1의 단백질 발현에 영향을 주어 DOX 처리에 의한 G1 세포주기 정지를 더욱 증가시켰다. 또한, PEMF는 DOX 처리에 의한 Fas와 Bcl-2-associated X의 증가, myeloid leukemia 1과 survivin의 감소, 카스파제(caspase)-8/9/7의 활성 및 poly (adenosine diphosphate-ribose) polymerase 절단을 더욱 증가시켰다. 이러한 연구결과를 바탕으로, 본 연구팀은 PEMF는 DOX 처리에 의한 G1 세포주기 정지와 카스파제 의존적 세포자멸사를 더욱 증가시켜 DOX 처리에 의한 MCF-7 세포의 생존율 감소를 더욱 증진시킴을 확인할 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2619-2623
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• 2014

Aim: To investigate signaling pathways for reversal of EGF-mediated multi-drug resistance (MDR) in hepatocellular carcinoma (HCC) models. Materials and Methods: HCC MDR cell strain HepG2/adriamycin (ADM) and SMMC7721/ADM models were established using a method of exposure to medium with ADM between low and high concentration with gradually increasing concentration. Drug sensitivity and reversal of multi-drug resistance by EGF were determined and the cell cycle distribution and apoptosis were analyzed by flow cytometry. Phosphorylation of ERK1, ERK2, ERK5 and expression of Bim were detected by Western blotting. Results: The results showed that HepG2/ADM and SMMC7721/ADM cells were resistant not only to ADM, but also to multiple anticancer drugs. When used alone, EGF had no anti-tumor activity in HepG2/ADM and SMMC7721/ADM cells in vitro, while it increased the cytotoxicity of ADM. EGF induced cell apoptosis and G0/G1 phase cell cycle arrest in HepG2/ADM And SMMC7721/ADM cells, while enhancing activity of p-ERKs and up-regulated expression of BimEL. Conclusions: EGF might enhance the chemosensitivity of HepG2/ADM and SMMC7721/ADM cells via up-regulating p-ERKs and BimEL protein.

• Natural Product Sciences
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• 제22권4호
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• pp.293-298
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• 2016

Plant-derived triterpenoids commonly possesses biological properties such as anti-inflammatory, antimicrobial, anti-viral and anti-cancer. Luvunga scandens is one of the plant that produced triterpenoids. The aims of the study was to analyze cell cycle profile and to determine the expression of p53 unregulated modulator of apoptosis (PUMA), caspase-8 and caspase-9 genes at mRNA level in MCF-7 cell line treated with two triterpenoids, flindissol (1) and 3-oxotirucalla-7,24-dien-21-oic-acid (2) isolated from L. scandens. The compounds were tested for cell cycle analysis using flow cytometer and mRNA expression level using quantitative RT-PCR. The number of MCF-7 cells population which distributed in Sub G1 phase after treated with compound 1 and 2 were 7.7 and 9.3% respectively. The evaluation of the expression of genes showed that both compounds exhibited high level of expression of PUMA, caspase-8 and caspase-9 as normalized to ${\beta}-actin$ via activation of those genes. In summary, the isolated compounds of L. scandens plant showed promising anticancer properties in MCF-7 cell lines.

• 동의생리병리학회지
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• 제27권3호
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• pp.306-312
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• 2013

Costunolide ($C_{15}H_{20}O_2$) is a sesquiterpene lactone that was isolated from many herbal medicines and it has diverse effects (anti-viral, anti-fungal, and anti-inflammatory) according to previous reports. However, the anti-cancer effects of Costunolide and its mechanism of actions are not well known in estrogen receptor positive breast cancer. In this study, we observed that costunolide suppresses cell growth in estrogen receptor positive MCF-7 breast cancer cells as shown by MTT assay and soft agar colony formation assay. To examine the mechanism by which costunolide inhibits MCF-7 cell growth, we performed FACS analysis. We found that costunolide induced G2/M and S cell cycle arrest, and regulated cycle-related protein expression. In addition, costunolide inhibited ERK signaling pathway and induced autophagy. Therefore, costunolide might be a good and useful chemotherapy agent for estrogen receptor positive breast cancer patients.

• Biomolecules & Therapeutics
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• 제20권3호
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• pp.313-319
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• 2012

In recent years, inhibition of HDACs has emerged as a potential strategy to reverse aberrant epigenetic changes associated with cancer, and several classes of HDAC inhibitors have been found to have potent and specific anticancer activities in preclinical studies. But their precise mechanism of action has not been elucidated. In this study, a novel synthetic inhibitor of HDAC, 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide [IN-2001] was examined for its antitumor activity and the underlying molecular mechanisms of any such activity on human breast cancer cell lines. IN-2001 effectively inhibited cellular HDAC activity ($IC_{50}$ = 0.585 nM) inMDA-MB-231 human breast cancer cells. IN-2001 caused a significant dose-dependent inhibition of cell proliferation in estrogen receptor (ER) negative MDA-MB-231human breast cancer cells. Cell cycle analysis revealed that the growth inhibitory effects of IN-2001 might be attributed to cell cycle arrest at $G_0/G_1$ and/or $G_2$/Mphase and subsequent apoptosis in human breast cancer cells. These events are accompanied by modulating several cell cycle and apoptosis regulatory genes such as CDK inhibitors $p21^{WAF1}$ and $p27^{KIP1}$ cyclin D1, and other tumor suppressor genes such as cyclin D2. Collectively, IN-2001 inhibited cell proliferation and induced apoptosis in human breast cancer cells and these findings may provide new therapeutic approaches, combination of antiestrogen together with a HDAC inhibitor, in the hormonal therapy-resistant ER-negative breast cancers. In summary, our data suggest that this histone deacetylase inhibitor, IN-2001, is a novel promising therapeutic agent with potent antitumor effects against human breast cancers.