• Journal of Applied Biological Chemistry
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• v.64 no.3
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• pp.263-268
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• 2021

7-Hydroxy-4-methylcoumarin (7H-4MC) inhibits hyaluronan production in multiple cell lines and tissue types both in vitro and in vivo. It is a commercially available drug approved for human use, called hymecromone, in European and Asian countries to prevent biliary spasms. Nevertheless, as the pharmacological efficacy of 7H-4MC has not yet been reported in macrophages, this study investigated its anti-inflammatory effects and mechanism of action using lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. LPS-induced RAW 264.7 cells were treated with various concentrations of 7H-4MC (62.5, 125, 250, and 500 μM). The application of 7H-4MC significantly reduced nitric oxide and prostaglandin E₂ production without cytotoxic effects. Additionally, 7H-4MC strongly decreased the expression of inducible nitric oxide synthase and cyclooxygenase. Furthermore, 7H-4MC reduced the production of proinflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. Finally, 7H-4MC exerted its potent anti-inflammatory actions via the upregulation of IκB-α production, which led to the inhibition of nuclear factor-κB (NF-κB) activity. These results, obtained in macrophage cell lines, suggest that 7H-4MC prevents inflammatory diseases via the NF-κB signaling pathway and that its use could be beneficial for human health. Ultimately, this is the first report describing the anti-inflammatory activity of 7H-4MC in a macrophage cell line.

• International Journal of Oral Biology
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• v.47 no.1
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• pp.9-15
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• 2022

Humulus japonicus (HJ) is a widely used herbal medicine for pulmonary tuberculosis, hypertension, leprosy, and venomous wounds in Asia, particularly in China. Although HJ has certain physiological activities, such as longitudinal bone growth, antioxidation and alleviation of rheumatism, its anticancer activities, other than in colorectal and ovarian cancer, are yet to be studied. In this study, we investigated the anti-cancer activity and mechanism of methanol extracts of HJ (MeHJ) against human FaDu hypopharyngeal squamous carcinoma cells. MeHJ suppressed FaDu cell viability without affecting normal cells (L929), which was demonstrated using the MTT and Live & Dead assays. Furthermore, MeHJ effectively inhibited colony formation of FaDu cells, even at non-cytotoxic concentrations, and significantly induced apoptosis through the proteolytic cleavage of caspase-9, -3, -7, poly (ADP-ribose) polymerase and through the downregulation of BCL-2 and upregulation of BAX in FaDu cells, as determined by DAPI staining, flow cytometry, and western blot analyses. Collectively, these findings suggest that the inhibitory effects of MeHJ on the growth and colony formation of oral cancer cells may be mediated by caspase- and mitochondrial-dependent apoptotic pathways in human FaDu hypopharyngeal squamous carcinoma cells. Therefore, MeHJ has the potential to be used as a natural chemotherapeutic drug against human oral cancer.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.265-273
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• 2022

Resistance to chemotherapeutic drugs is a significant problem in the treatment of colorectal cancer, resulting in low response rates and decreased survival. Recent studies have shown that shikonin, a naphthoquinone derivative, promotes apoptosis in colon cancer cells and cisplatin-resistant ovarian cells, raising the possibility that this compound may be effective in drug-resistant colorectal cancer. The aim of this study was to characterize the molecular mechanisms underpinning shikonin-induced apoptosis, with a focus on endoplasmic reticulum (ER) stress, in a 5-fluorouracil-resistant colorectal cancer cell line, SNU-C5/5-FUR. Our results showed that shikonin significantly increased the proportion of sub-G₁ cells and DNA fragmentation and that shikonin-induced apoptosis is mediated by mitochondrial Ca²⁺ accumulation. Shikonin treatment also increased the expression of ER-related proteins, such as glucose regulatory protein 78 (GRP78), phospho-protein kinase RNA-like ER kinase (PERK), phospho-eukaryotic initiation factor 2 (eIF2α), phospho-phosphoinositol-requiring protein-1 (IRE1), spliced X-box-binding protein-1 (XBP-1), cleaved caspase-12, and C/EBP-homologous protein (CHOP). In addition, siRNA-mediated knockdown of CHOP attenuated shikonin-induced apoptosis, as did the ER stress inhibitor TUDCA. These data suggest that ER stress is a key factor mediating the cytotoxic effect of shikonin in SNU-C5/5-FUR cells. Our findings provide an evidence for a mechanism in which ER stress leads to apoptosis in shikonin-treated SNU-C5/5-FUR cells. Our study provides evidence to support further investigations on shikonin as a therapeutic option for 5-fluorouracil-resistant colorectal cancer.

• BMB Reports
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• v.55 no.10
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• pp.506-511
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• 2022

Advanced hepatocellular carcinoma (HCC) is among the most challenging cancers to overcome, and there is a need for better therapeutic strategies. Among the different cancer drugs that have been used in clinics, sorafenib is considered the standard first-line drug for advanced HCC. Here, to identify a chemical compound displaying a synergistic effect with sorafenib in HCC, we screened a focused chemical library and found that MG149, a histone acetyltransferase inhibitor targeting the MYST family, exhibited the most synergistic anticancer effect with sorafenib on HCC cells. The combination of sorafenib and MG149 exerted a synergistic anti-proliferation effect on HCC cells by inducing apoptotic cell death. We revealed that cotreatment with sorafenib and MG149 aggravated endoplasmic reticulum (ER) stress to promote the death of HCC cells rather than adaptive cell survival. In addition, combined treatment with sorafenib and MG149 significantly increased the intracellular levels of unfolded proteins and reactive oxygen species, which upregulated ER stress. Collectively, these results suggest that MG149 has the potential to improve the efficacy of sorafenib in advanced HCC via the upregulation of cytotoxic ER stress.

• BMB Reports
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• v.55 no.12
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• pp.645-650
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• 2022

Epithelial-to-mesenchymal transition (EMT)-subtype gastric cancers have the worst prognosis due to their higher recurrence rate, higher probability of developing metastases and higher chemo-resistance compared to those of other molecular subtypes. Pharmacologically actionable somatic mutations are rarely found in EMT-subtype gastric cancers, limiting the utility of targeted therapies. Here, we conducted a high-throughput chemical screen using 37 gastric cancer cell lines and 48,467 synthetic small-molecule compounds. We identified YK-135, a small-molecule compound that showed higher cytotoxicity toward EMT-subtype gastric cancer cell lines than toward non-EMT-subtype gastric cancer cell lines. YK-135 exerts its cytotoxic effects by inhibiting mitochondrial complex I activity and inducing AMP-activated protein kinase (AMPK)-mediated apoptosis. We found that the lower glycolytic capacity of the EMT-subtype gastric cancer cells confers synthetic lethality to the inhibition of mitochondrial complex I, possibly by failing to maintain energy homeostasis. Other well-known mitochondrial complex I inhibitors (e.g., rotenone and phenformin) mimic the efficacy of YK-135, supporting our results. These findings highlight mitochondrial complex I inhibitors as promising therapeutic agents for EMT-subtype gastric cancers and YK-135 as a novel chemical scaffold for further drug development.

• Journal of dental hygiene science
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• v.23 no.3
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• pp.216-224
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• 2023

Background: Smilax glabra has various pharmacological activities and is widely used as a herbal medicine. Although the incidence of oral cancer is low, the recurrence rate is high, and the 5-year survival rate is poor. It is necessary to search for anticancer drugs that increase the effect of cancer chemotherapy on heterogeneous oral tissues and reduce the side effects on normal cells. This study aimed to investigate the effects and mechanism of ethanol extract of Smilax glabra (EESG) as an anticancer drug for oral cancer. Methods: Smilax glabra root components extracted with 70% ethanol were used to analyze their effects on cancer cells. A 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay was performed for cytotoxicity analysis. Flow cytometry was performed to determine the cell cycle phase distribution. To observe apoptotic cells, terminal deoxynucleotidyl transferase dUTP nick end labeling and γH2AX were detected by fluorescence microscope. The protein levels of cleaved PARP and caspase were analyzed using western blotting. The activation of procaspase-3 was confirmed by measuring caspase-3 activity. Results: EESG was no cytotoxic to normal gingival fibroblast but was high in YD10B oral squamous cell carcinoma (OSCC) cells. EESG treatment increased the subdiploid DNA content of YD10B cells by assessing DNA content distribution. Chromatin condensation and DNA strand breaks increased in YD10B cells treated with EESG. EESG-treated YD10B cells had high Annexin V and low propidium iodide levels, confirming that early apoptosis was induced. In addition, increased levels of γH2AX foci, a marker of DNA damage, were observed in the nuclei of EESG-treated YD10B cells. The EESG-treated YD10B cells also exhibited decreased procaspase-3 and procaspase-9 levels, increased PARP cleavage and caspase-3 activity. Conclusion: These results indicate that EESG inhibited cancer cell proliferation by inducing apoptosis in YD10B OSCC cells.

• Anatomy and Cell Biology
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• v.57 no.1
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• pp.85-96
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• 2024

Glioblastoma is the most common primary malignant brain tumor in adults. Temozolomide (TMZ) is an FDA-approved drug used to treat this type of cancer. Cinnamaldehyde (CIN) is a derivative of cinnamon extract and makes up 99% of it. The aim of this study was to investigate the in vitro combined effect of CIN and TMZ on human glioblastoma multiforme T98G cell line viability. In this study, we used 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl-tertazolium bromide (MTT) method to evaluate the extent of IC₅₀, acridine orange, Giemsa and Hoechst staining to evaluate the manner of apoptosis and the Western blotting method to examine the expression change of apoptotic proteins. Our results show that TMZ has an inhibitory effect on CIN when both used in combination at concentrations of 300 and 100 µM (P<0.05) and has a cytotoxic effect when used alone at the same concentrations (P<0.05). The western blotting result showed that TMZ at concentrations of 2,000 and 1,000 µM significantly increased Bax expression and decreased Bcl2 expression (P<0.05), indicating that TMZ induced apoptosis through the mitochondrial pathway. However, CIN had no effect on Bax and Bcl2 expressions, thus causing apoptosis from another pathway. Also, the Bax:Bcl2 expression ratio at concentrations combined was lower than that for TMZ 1,000 µM and higher than that for CIN 150 and 100 µM (P<0.05), which confirms the inhibitory effect of TMZ on CIN. From the present study, we conclude that TMZ in combination with CIN has an inhibitory effect on increasing the cytotoxicity rate.

• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.302-313
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• 1995

Background: Tumor necrosis factor(TNF) showed antitumor cytolytic effects on sensitive tumor cells in numerous in vivo and in vitro studies. But it could not be administered systemically to human because of severe systemic adverse effects at effective concentrations against tumor cells. Many studies showed that a high concentrations of TNF in the local milieu may evoke in vivo TNF-responsive mechanisms sufficient to suppress tumor growth. Recently developed technique of TNF gene transfer to tumor cells using retrovirus vector could be a good candidate for local TNF administration. TNF is also known to synergistically enhance in vitro cytotoxicity of chemotherapeutic drugs targeted to DNA topoisomerase II against TNF-sensitive tumor cell lines. In this study the in vitro chemosensitivity against DNA topoisomerase II targeted chemotherapeutic drugs was evaluated using some respiratory cancer cell lines to which TNF gene had been transferred. Method: NCI-H2058, a human mesothelioma cell line, A549, a human lung adenocarcinoma cell line and WEHI 164 cell line, a murine fibrosarcoma cell line were treated with etoposide and doxorubicin, which are typical topoisomerase II - targeted chemotherapeutic agents, at different concentration. The resultant cytotoxicity was measured by MIT assay. Then the cytotoxicity of the same chemotherapeutic agents was measured after TNF-$\alpha$ gene-transfer and the two results were compared. Results: The cytotoxicity was not increased significantly in WEHI164 cell line and A549 cell line but statistically significant increase was observed in H2058 cell line when TNF-$\alpha$ gene was transferred(p<0.05). Conclusion: These findings show that TNF-$\alpha$ gene transfer to respiratory cancer cell lines results in variable effects on chemosensitivity against topoisomerase II inhibitor among different cell lines in vitro and can be additively cytotoxic in certain selective tumor cell lines.

• Radiation Oncology Journal
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• v.21 no.3
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• pp.207-215
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• 2003

Purpose: Extracellular signal-regulated kinase (ERK), which is part of the mitogen-activated protin kinase cascade, opposes initiation of the apoptotic cell death which is programmed by diverse cytotoxic stimuli. In this regard, the inhibition of ERK may be useful in improving the therapeutic efficacy of established anticancer agents. Materials and Methods: Murine hepatocarcinoma, HCa-I is known to be highly radioresistant with a TCD50 (radiation dose yield in $50\%$ cure) of more than 80 Gy. Various anticancer drugs have been found to enhance the radioresponse of this particular tumor but none were successful. The objective of this study was to explore whether the selective inhibition of MEK could potentiate the antitumor efficacy of radiation in vivo, particularly in the case on radioresistant tumor. C3H/HeJ mice hearing $7.5\~8\;mm$ HCa-I, were treated with PD98059(intratumoral injection of $0.16\;\mug/50\;\mul$). Results: Downregulation on ERK by PD98059 was most prominent 1h after the treatment. In the tumor growth delay assay, the drug was found to Increase the effect of the tumor radioresponse with an enhancement factor (EF) of 1.6 and 1.87. Combined treatment of 25 Gy radiation with PD98059 significantly increased radiation induced apoptosis. The peak apoptotic index (number on apoptotic nuclei in 1000 nuclei X100) was $1.2\%$ in the case of radiation treatment alone, $0.9\%$ in the case of drug treatment alone and $4.9\%,\;5.3\%$ in the combination treatment group. An analysis of apoptosis regulating molecules with Western blotting showed upregulation of p53, p$p21^{WAF1/CIP1}\;and\;Bcl-X_s$ in the combination treatment group as compared to their levels in either the radiation alone or drug alone treatment groups. The level of other molecules such as $Bcl-X_L4, Bax and Bcl-2 were changed to a lesser extent. Conclusion: The selective inhibition of MEK in combination with radiation therapy may have potential benefit in cancer treatment.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.19-30
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• 2005

This study was to evaluate the biological activity of flavor components extracted from E. ciliata and E. splendens in order to survey the possibility applicable to tobacco and food industry. Flavor components were extracted with dividing into three parts; essential oil, absolute, oleoresin. In the nonenzymatic lipid peroxidation system, the inhibition rate($\%$) of essential oil were $67.3\;\pm\;20.7\%,\;58.1\;\pm\;19.3\%$ at the concentration of 50 ${\mu}g/mL$ of E. ciliata and E. splendens, respectively. The inhibition rate($\%$) of the oleoresin in E. ciliata was higher than one in E. splendens. In the enzymatic lipid peroxidation system, the inhibition rate($\%$) of essential oil and oleoresin was$14.28\;\pm\;2.38\%,\;and\;65.93\;\pm\;0.01\%,\;and\;was\;22.58\;\pm\;2.84\%\;and\;40.73\;pm\;6.04\%$. The oleoresin of two species were showed above $90\%$ of the inhibition rate($90\%$) against autooxidative lipid peroxidation system. $EC_{50}$ values in neutral red uptake assays 24 h of exposure times were $23.3\;{\mu}g/mL,\;341.0\;{\mu}g/mL\;and\;17.2\;{\mu}g/mL$ in essential oil, absolute and oleoresin from E. ciliata respectively, and were $46.4\;{\mu}g/mL,\;681.7\;{\mu}g/mL\;17.6\;{\mu}g/mL$ in three extractions of E. splendens. Oleoresin of two species showed high rate in the cytotoxic effect by neutral red uptake assay. Absolute and oleoresin did not show antibiotic and mutagenic activity. On the contrary, essential oil with over 500 ug/plate showed antibiotic and mutagenic activity in Ames test. Essential oil and oleoresin have a prolongating effect the ciliostasis of rat trachea. This results indicate that flavor components extracted from E. ciliata and E. splendens can be considered to be toxicological safe and to be the possibility applicable the cigarette, food and drug industry as a flavor for expectoration.