• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.67-75
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• 2001

Background : Two tumor suppressor genes, p53 and p16, which have different roles in controlling the cell cycle and inducing apoptosis, are frequently inactivated during carcinogenesis including lung cancer. Single tumor suppressor gene therapies using either with p53 or p16 have been studied extensively. However, there is a paucity of reports regarding a combined gene therapy using these two genes. Methods : The combined effect of p53 and p16 gene transfer by the adenoviral vector on the growth of lung cancer cell lines and its interactive mechanism was investigated. Results : An isobologram showed that the co-transduction of p53 and p16 exhibited a synergistic growth in hibitory effect on NCI H358 and an additive effect on NCI H23. Cell cycle analysis demonstrated the induction of a synergistic G1/S arrest by a combined p53 and p16 transfer. This synergistic interaction was again confirmed in a soft agar confirmed in a soft agar clonogenic assay. Conclusion : These observations suggest the potential of a p53 and p16 combination gene therapy as another potent strategy in cancer gene therapy.

• Radiation Oncology Journal
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• v.7 no.2
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• pp.149-156
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• 1989

Multicellular tumor spheroids of HeLa cells have been grown in a static culture system. Samples of spheroids were exposed for 2 h to graded concentration of cis-platinum and its analogue, carboplatin, and then response assayed by survival of clonogenic cells. The purpose of present experiment is to clarify the effectiveness of these platinum compounds and to evaluate intrinsic radiosensitivity of cells using spheroids of HeLa cells as an experimental in vitro model. Variations of the drug sensitivity of monolayers as well as spheroids were also evaluated in cell-survival curves. In cis-platinum concentration-survival curve, there was a large shoulder extending as far as $Cq=3.4{\mu}M$, after which there was exponential decrease in survival curve having a Co Value of $1.2{\mu}M$ in spheroids. While the Co for the spheroids was essentially no significant change, but Cq value was larger than that of monolayers. This suggest that the effect of cis-platinum is greater En the monolayer with actively proliferaing cells than hypoxic one. In the carboplatin concentration-survival curves, the Co value of spheroids was $15.0{\mu}M$ and the ratio with the Co from monolayer cell $(32.5{\mu}M)$ was 0.40, thus indicating that the spheroids had a greater sensitivity to carboplatin than monolayers. Therefore, the effect of carboplatin is mainly on the deeper layers of spheroids acting as hypoxic cell sensitizer. The enhanced effect was obtained for monolayer cells using combined X-ray and carboplatin treatment 2 hours before irradiation. The result shown in isobologram analysis for the level of surviving fraction at 0.01 indicated that the effect of two agents was trusty supra-additive. From this experimental data, carboplatin has excited much recent interest as one of the most promising, since it is almost without nephrotoxicity and causes less gastrointestinal toxicity than cis-platinum. Interaction between carboplatin and radiation might play an important role for more effective local tumor control.

• The Journal of the Korean Society for Microbiology
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• v.21 no.3
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• pp.375-380
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• 1986

Thirty-one strains of Pseudomonas aeruginosa were submitted to the synergistic activity test of amikacin(AK) and gentamicin(GM) combined with moxalactam(MX), ceftizoxime(CTZ) or cefoperazone(CFZ). The minimal inhibitory concentrations(MICs) of each drug and drugs combined in various ratios were measured by checkerboard dilution method. The synergism was determined through analysing the MIC distribution curve on isobologram and calculating the fractional inhibitory concentration index(FICI). MICs of GM, AK, MX, CFZ and CTZ against the 31 tested strains were distributed from $12.5{\mu}g/ml$ to $800{\mu}g/ml$, from $0.8{\mu}g/ml$ to $25{\mu}g/ml$, from $3.1{\mu}g/ml$ to $50{\mu}g/ml$, from $3.1{\mu}g/ml$ to $400{\mu}g/ml$, and from $12.5{\mu}g/ml$ to $100{\mu}g/ml$, respectively. The rate synergism of each drug combination by means of FICl was 45.5% in GM-MX, 36.4% in GM-CFZ, 63.6% in GM-CTZ, 48.6% in AK-MX, 35.3% in AK-CFZ, and 35.7% in AK-CTZ combination. Thus, it is suggested that Pseudomonas aeruginosa may effectively be inhibited by various aminoglycoside and cephalosporin combinations.

• Natural Product Sciences
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• v.25 no.4
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• pp.311-316
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• 2019

Artocarpus heterophyllus has been used as traditional medicine. This plant is one of the sources of flavonoid. Flavonoid compounds possessed a wide range of biological properties including anticancer. This study was performed to investigate the cytotoxic effect of flavonoids from A. heterophyllus on H460 and MCF-7 cell lines. The interaction of flavonoids and cisplatin against tested cancer cells was also evaluated. MTT assay was used to determine the cytotoxic effect of flavonoid. Isobologram analysis was selected to evaluate the synergistic effect between flavonoid and cisplatin, their interaction was then confirmed using AO/PI staining method. Amongst of flavonoid compounds, artocarpin exhibited strong cytotoxic effect on both MCF-7 and H460 cell lines with IC₅₀ values of 12.53 ㎍/mL (28.73 μM) and 9.77 ㎍/mL (22.40 μM), respectively. This compound enhanced anticancer activity of cisplatin against H460 and MCF-7. The combination produced a synergistic effect on H460 and MCF-7 cell lines with a combination index (CI) values of 0.2 and 0.18, respectively. The AO/PI stained demonstrated that the combination of artocarpin and cisplatin caused morphological changes that indicated apoptosis. Moreover, artocarpanone also significantly increased cytotoxic effect of cisplatin compared to its single concentration with CI below than 1. This result suggested the potency of flavonoid named artocarpin to enhance the anticancer activity of cisplatin on H460 and MCF-7 cell lines.

• Biomolecules & Therapeutics
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• v.28 no.5
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• pp.473-481
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• 2020

Axl receptor tyrosine kinase has been implicated in cancer progression, invasion, and metastasis in various cancer types. Axl overexpression has been observed in many cancers, and selective inhibitors of Axl, including R428, may be promising therapeutic agents for several human cancers, such as breast, lung, and pancreatic cancers. Here, we examined the cell growth inhibition mediated by R428 and auranofin individually as well as in combination in the human breast cancer cell lines MCF-7 and MDA-MB-231 to identify new advanced combination treatments for human breast cancer. Our data showed that combination therapy with R428 and auranofin markedly inhibited cancer cell proliferation. Isobologram analyses of these cells indicated a clear synergism between R428 and auranofin with a combination index value of 0.73. The combination treatment promoted apoptosis as indicated by caspase 3 activation and poly (ADP-ribose) polymerase cleavage. Cancer cell migration was also significantly inhibited by this combination treatment. Moreover, we found that combination therapy significantly increased the expression level of Bax, a mitochondrial proapoptotic factor, but decreased that of the X-linked inhibitor of apoptosis protein. Furthermore, the suppression of cell viability and induction of Bax expression by the combination treatment were recovered by treatment with N-acetylcysteine. In conclusion, our data demonstrated that combined treatment with R428 and auranofin synergistically induced apoptosis in human breast cancer cells and may thus serve as a novel and valuable approach for cancer therapy.

• Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.133-144
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• 2023

Auranofin is a US Food and Drug Administration (FDA)-approved anti-arthritis medication that functions as a thioredoxin reductase inhibitor. Spermidine, a polyamine present in marine algae, can exert various physiological functions. Herein, we examined the synergistic anticancer activity of auranofin and spermidine in hepatocellular carcinoma (HCC). Combined treatment with auranofin and spermidine suppressed cell viability more efficiently than either treatment alone in HCC Hep3B cells. The isobologram plotted by calculating the half maximal inhibitory concentration (IC₅₀) values of each drug indicated that the two drugs exhibited a synergistic effect. Based on the analysis of annexin V and cell cycle distribution, auranofin and spermidine markedly induced apoptosis in Hep3B cells. Moreover, auranofin and spermidine increased mitochondria-mediated apoptosis by promoting mitochondrial membrane potential (Δψm) loss. Auranofin and spermidine significantly increased reactive oxygen species (ROS) production in Hep3B cells, and the blocking ROS suppressed apoptosis induced by spermidine and auranofin. In addition, auranofin and spermidine reduced the expression of phosphorylated phosphatidylinositol-3 kinase (PI3K) and protein kinase B (Akt), and PI3K inhibitor accelerated auranofin- and spermidine-induced apoptosis. Using ROS scavenger and PI3K inhibitor, we revealed that ROS acts upstream of auranofin- and spermidine-induced apoptosis. Collectively, our study suggests that combination treatment with auranofin and spermidine could afford synergistic anticancer activity via ROS overproduction and reduced PI3K/Akt signaling pathway.

• Biomolecules & Therapeutics
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• v.29 no.2
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• pp.234-247
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• 2021

We used a heterozygous gene deletion library of fission yeasts comprising all essential and non-essential genes for a microarray screening of target genes of the antifungal terbinafine, which inhibits ergosterol synthesis via the Erg1 enzyme. We identified 14 heterozygous strains corresponding to 10 non-essential [7 ribosomal-protein (RP) coding genes, spt7, spt20, and elp2] and 4 essential genes (tif302, rpl2501, rpl31, and erg1). Expectedly, their erg1 mRNA and protein levels had decreased compared to the control strain SP286. When we studied the action mechanism of the non-essential target genes using cognate haploid deletion strains, knockout of SAGA-subunit genes caused a down-regulation in erg1 transcription compared to the control strain ED668. However, knockout of RP genes conferred no susceptibility to ergosterol-targeting antifungals. Surprisingly, the RP genes participated in the erg1 transcription as components of repressor complexes as observed in a comparison analysis of the experimental ratio of erg1 mRNA. To understand the action mechanism of the interaction between the drug and the novel essential target genes, we performed isobologram assays with terbinafine and econazole (or cycloheximide). Terbinafine susceptibility of the tif302 heterozygous strain was attributed to both decreased erg1 mRNA levels and inhibition of translation. Moreover, Tif302 was required for efficacy of both terbinafine and cycloheximide. Based on a molecular modeling analysis, terbinafine could directly bind to Tif302 in yeasts, suggesting Tif302 as a potential off-target of terbinafine. In conclusion, this genome-wide screening system can be harnessed for the identification and characterization of target genes under any condition of interest.

• The Journal of the Korean bone and joint tumor society
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• v.4 no.1
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• pp.13-21
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• 1998

Taxol, the extract from the Taxus brevifolia which is a Pacific yew tree has aroused the interest of the tumor investigators since the 1960s. As well, it is shown to have broad antitumor activity in preclinical experimental models. Its action mechanism is an anti-microtubule effect by duplication of tubulin. The most impressive antitumor activity of taxol has been observed in advanced ovarian cancer and metastatic breast cancer. The purpose of this study was to determine how taxol acts on malignant bone tumor cell lines, to compare its cytotoxic effect with those of other chemotherapeutic agents, and to ascertain the its combination effect with adriamycin. Cell lines used in this study were G-292(osteosarcoma, human), SaOS-2(osteosarcoma, primary, human), and HT-1080(fibrosarcoma, human). Methotrexate, adriamycin, cisplatinum, ifosfamide and taxol were used as testing chemotherapeutic agents and their maximum test concentration were $500{\mu}g/ml$, $200{\mu}g/ml$, $500{\mu}g/ml$, $1000{\mu}g/ml$, and $600{\mu}g/ml$, respectively. The media for cell culture was RPMI-1640 with 10% fetal bovine serum and gentamycin. The results were as follows. The $IC_{50}$ of methotrexate, ifosfamide, cisplatinum, adriamycin and Taxol in G-292 were $2.3{\times}10^{-1}{\mu}g/ml$, $8.0{\times}10^0{\mu}g/ml$, $3.5{\times}10^0{\mu}g/ml$, $9.8{\times}10^{-1}{\mu}g/ml$, $2.7{\times}10^{-2}{\mu}g/ml$ respectively, in SaOS-2 $3.5{\times}10^{-1}{\mu}g/ml$, $1.5{\times}10^1{\mu}g/ml$, $2.8{\times}10^0{\mu}g/ml$, $9.9{\times}10^{-2}{\mu}g/ml$, $1.0{\times}10^{-2}{\mu}g/ml$, respectively, in HT-1080 $4.2{\times}10^{-2}{\mu}g/ml$, $5.4{\times}10^1{\mu}g/ml$, $3.8{\times}10^0{\mu}g/ml$, $5.5{\times}10^{-3}{\mu}g/ml$, $1.1{\times}10^{-3}{\mu}g/ml$, respectively. In conclusion, taxol had very potent cytotoxic effect on the malignant bone tumor cell lines with adriamycin, and was more potent than methotrexate, cisplatinum and ifosfamide. There were synergistic antitumor effects on G-292 and SaOS-2 cell lines in combination test of taxol and adriamycin. From the above results, it would be estimated that taxol could be a new antitumor drug for the malignant bone tumors, providing measures against the side effects and followed by the clinical tests.