• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.192-197
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• 2009

Camptotheca acuminata, a native of South China is a well known natural source of monoterpene-indole alkaloid camptothecin(CPT), one of the most promising anti-tumoural compounds. This study was conducted to optimize plant growth regulators and culture conditions on plantlets regeneration through organogenesis from callus of Camptotheca acuminta. Callus were induced from various explants of in vitro germinated plantlets of C. acuminta using WPM medium containing 0.2 ㎎/L 2,4-D. Hypocotyl segments were exhibited higher embryogenic callus than the other explants. Shoot buds formation from embryogenic callus was affected by plant growth regulators, pre-treated dark condition and liquid culture. Organogenesis was optimal in WPM liquid medium containing 0.5 ㎎/L BA. The dark pre-treatment for 2 weeks before the solid culture was effective for organogenesis. The regenerated shoots were rooted in WPM medium with 0.2 ㎎/L NAA and successfully acclimated in green-house conditions.

• Plant Biotechnology Reports
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• v.2 no.2
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• pp.163-169
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• 2008

Roots of Ophiorrhiza prostrata D. Don serve as a rich source of camptothecin (CPT), an anticancer drug. Because of the large-scale collection of its roots, the plant has become a threatened species. The present study accomplishes the induction of adventitious roots as a means for the production of CPT as well as for the large-scale propagation of this anticancer drug plant using leaf and internode explants. The biomass yield and CPT content of adventitious roots induced from different explants were compared to roots developed on ex vitro rooted stem cuttings. Adventitious roots were produced on half-strength Murashige and Skoog (MS) medium supplemented with $10.74{\mu}M$ ${\alpha}-naphthaleneacetic$ acid and $2.32{\mu}M$ kinetin at mean fresh weights of 0.753, 0.739 and 0.748 g roots from leaf, internode and shoot, respectively. CPT yield from in vitro derived roots after 50, 80 and 120 days of incubation (0.028, 0.06 and 0.1% dry weight, respectively) was not significantly different from those harvested at the same age from ex vitro rooted (0.03, 0.06 and 0.13%, respectively) stem cuttings. CPT from subcultured roots derived from solid (0.08%) medium was lower than from suspension culture medium (0.12%). Subsequent cultures of the adventitious roots showed a stable production of CPT (0.16%). The yield of CPT from 360-day-old plant-derived roots was 0.19%. Elicitation using methyl jasmonate and acetyl salicylic acid exhibited no enhancement in CPT yield. In vitro propagation through direct shoot regeneration was achieved from the adventitious roots upon transfer to MS medium with $8.87{\mu}M$ $N^6-benzyladenine$ (BA) and $2.46{\mu}M$ indole-3-butyric acid (IBA) with a mean of 21.2 shoots per culture in 50 days. The shoots upon subculture on medium having the same level of BA and IBA underwent rapid proliferation. The shoots transferred to field conditions after in vitro rooting exhibited 95% survival. Adventitious root induction, from leaf and internode explants, enables the feasible production of CPT as well as the large-scale rapid propagation of this species which can safeguard it from extinction.

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.89-91
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• 1998

Cryptotanshinone induced topoisomerase I-mediated DNA cleavage in vitro as strongly as camptothecin, whereas topoisomerase II-mediated DNA cleavage was not induced by this agent. In DNA relaxation assay using calf thymus DNA topoisomerase I and supercoiled pBR322 DNA, cryptotanshinone inhibited topoisomerase I-mediated DNA relaxation in a dose-dependent manner. In unwinding assay, cryptotanshinone ($50{\mu}M$) did not shift the topoisomers of DNA. These results suggest that cryptotanshinone exerted a preferential inhibition of topoisomerase I without intercalating into DNA.

• Tuberculosis and Respiratory Diseases
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• v.66 no.2
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• pp.93-97
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• 2009

Background: Belotecan (Camtobell, CKD-602, Chongkundang Pharm., Korea), a camptothecin derivative, has anticancer effects by inhibiting topoisomerase I such as topotecan. This study observed the response, survival and toxicity of belotecan monotherapy after the failure of etoposide and platinum (EP). Methods: Forty nine small cell lung cancer (SCLC) patients (M/F=41/8; age, 64.5${\pm}$7.6 (mean${\pm}$SD) years), who failed in their first line chemotherapy were enrolled in this study. Twenty one SCLC patients showed relapsed lung cancer more than 90 days after their priorEP chemotherapy (sensitive relapse group, SR) and 28 patients relapsed within 90 days (refractory relapse group, RR). Results: The response rate was 25%. Eleven patients showed partial responses and 5 patients could not be checked. The response rate of the SR and RR patients was similar. The relative dose intensity was lower in the responders (78${\pm}$15%) than non-responders (83${\pm}$13%, p=0.03). The median survival time (MST) was 10.3 months (290 days). The MST of the non-responders and responders was 186 days (95% CI; 67-305) and 401 days (95% CI; 234-568, p=0.07), respectively. The median progression free survival (MPFS) was similar in the SR (79 days) and RR (67 days) patients. Grade 3-4 neutropenia, anemia, and thrombocytopenia were observed in 59.6%, 12.8% and 23.4% of patients, respectively. Conclusion: The efficacy and survival were demonstrated in the second-line setting. However, a randomized comparative trial with topotecan will be needed.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.129-134
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• 1998

To evaluate the genotoxicity of CKD-602, an anticancer agent the in viかo reverse mutation assay using Salmonella typhimurium, the Chromosome aberration assay using Chinese hamster lung (CHL) cells and the in vivo micronucleus assay using bone marrow cells of ddY mice were performed. In the reverse mutation assay, CKD-602 did not induced mutagenicity in Salmonella typhimurium TA 98, TA 100, TA 1535, and TA 1537 strains with and without metabolic activation. In the chromosome aberration test using CHL cells, there was an increased incidence of structural aberrations induced by CKD-602 without metabolic activation during 24 and 48 hours, but CKD-602 did not induce chromosome aberration with metabolic activation. The in vivo induction of micronuclei was measured in polychromatic erythrocytes of bone marrow of male ddY mice. At 24 hours after treatment with CED-602 by i.p. once, there was an increased incidence of micronucleated polychromatic erythrocytes in bone marrow of ddY male mice.

• Natural Product Sciences
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• v.7 no.2
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• pp.60-62
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• 2001

Ulmus davidiana, Formitella fraxinea, and Aloe vera extracts were detected to have inhibitory effects against topoisomerase I at treatment of $5{\mu}g$. Ulmus davidiana and Aloe vera extracts were found to show inhibitory effect similar to camptothecin, Formitella fraxinea extract was found to have weak activity. We also found the potential use of those extracts as a radiation sensitizer. Radiosensitizing effect at combination treatment was increased more than 2 times at single treatment of radiation, Ulmus davidiana or Formitella fraxinea extracts. Ulmus davidiana and Formitella fraxinea extracts were found to have significant radiosensitizing effect on test tumor cell line. But, Aloe vera extract was not detected to have activity as a radiosensitizer. Ulmus davidiana and Formitella fraxinea extracts are potent radiosensitizers on tumor cell lines and should be considered for further study of active compounds.

• Molecules and Cells
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• v.40 no.2
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• pp.83-89
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• 2017

Error-free replication and repair of DNA are pivotal to organisms for faithful transmission of their genetic information. Cells orchestrate complex signaling networks that sense and resolve DNA damage. Post-translational protein modifications by ubiquitin and ubiquitin-like proteins, including SUMO and NEDD8, are critically involved in DNA damage response (DDR) and DNA damage tolerance (DDT). The expression of interferon-stimulated gene 15 (ISG15), the first identified ubiquitin-like protein, has recently been shown to be induced under various DNA damage conditions, such as exposure to UV, camptothecin, and doxorubicin. Here we overview the recent findings on the role of ISG15 and its conjugation to target proteins (e.g., p53,$ {\Delta}Np63{\alpha}$, and PCNA) in the control of cellular responses to genotoxic stress, such as the inhibition of cell growth and tumorigenesis.

• Toxicological Research
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• v.20 no.1
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• pp.83-88
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• 2004

The present study was carried out to investigate the potential adverse effects of CKD-602 by a 5-day repeated intravenous dose in Sprague-Dawley rats. The test article, CKD-602, was administered intravenously to male and female rats at dose levels of 0.07, 0.22, 0.67, 2.0 and 6.0 mg/kg/day for 5 days consecutively. Mortalities, clinical findings, and body weight changes were monitored for the 14-day period after cessation of the administration. At the end of 14-day observation period, all animals were sacrificed and complete gross postmortem examinations were performed. There were 2 and 5 treatment related deaths in the 0.67 and 2.0 mg/kg/day dose groups of both genders, respectively. Treatment related clinical signs, including hair loss, skin paleness, decreased locomotor activity, emaciation, and changes in stool were observed in a dose-dependent manner from the third day after initiation of the injection. Decrease or suppression of body weight was also observed dose-dependently in males and females of the treated groups. Gross postmortem examinations revealed a dose-dependent increase in the incidence and severity of atrophy or hypertrophy and white membrane formation in the spleen, atrophy of the thymus, diffuse white spots and paleness of the liver, paleness of the lung, kidney and adrenal gland, and dark red discoloration and dark red contents in the alimentary tract. Based on these results, it was concluded that the 5-repeated intravenous injection of CKD-602 to male and female rats resulted in increased incidence of abnormal clinical signs and death, decreased or suppressed body weight, and increased incidence of abnormal gross findings. In the present experimental conditions, the $LD_{50}$ value was 2.07 (95% confidence limit not specified) mg/kg/day in both genders and the $LD_{10}$ value was 1.72 (95% confidence limit not specified) mg/kg/day in both genders.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.49-55
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• 2004

The present study was carried out to investigate the potential acute toxicity of CKD-602 by a single intravenous dose in Beagle dogs. The test chemical was administered intravenously to male and female Beagle dogs at dose levels of 0.3, 0.5, or 2.5 mg/kg. Mortalities, clinical findings, and body weight changes were monitored for the 14-day period following the administration. At the end of 14-day observation period, all animals were sacrificed and complete gross postmortem examinations were performed. All males and females of the 2.5 mg/kg dose group were found dead between the fourth and seventh day after the injection. Treatment related clinical signs, including vomiting, anorexia, mucous stool, diarrhea, and no stool were observed. Decrease or suppression of body weight was observed in a dose-dependent manner. In autopsy, dark red discoloration of the gastrointestinal tract, atrophy of the thymus, paleness of the spleen, sporadic dark red spots of the lung and petechia of the heart were observed in dead animals of the 2.5 mg/kg dose group. There were no specific adverse effects on males and females of the 0.3 and 0.5 mg/kg dose groups, except for the transient clinical signs such as anorexia, vomiting, and mucus/no stool. On the basis of the results, it was concluded that a single intravenous injection of CKD-602 to Beagle dogs resulted in increased incidence of abnormal clinical signs and death, decreased body weight, and increased incidence of abnormal gross findings. The absolute toxic dose of this chemical was 2.5 mg/kg for both genders. The $LD_{50}$ value was 1.1 mg/kg (95% confidence limit not specified) for both genders. The no-observed-effect level (NOEL) was considered to be below 0.3 mg/kg for both genders.

• BMB Reports
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• v.41 no.2
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• pp.112-118
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• 2008

Camptothecin is an anti-cancer monoterpene indole alkaloid. The gene encoding 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (designated as CaHDR), the last catalytic enzyme of the MEP pathway for terpenoid biosynthesis, was isolated from camptothecin-producing Camptotheca acuminata. The full-length cDNA of CaHDR was 1686 bp encoding 459 amino acids. Comparison of the cDNA and genomic DNA of CaHDR revealed that there was no intron in genomic CaHDR. Southern blot analysis indicated that CaHDR belonged to a low-copy gene family. RT-PCR analysis revealed that CaHDR expressed constitutively in all tested plant organs with the highest expression level in flowers, and the expression of CaHDR could be induced by 100 ${\mu}M$ methyl-jasmonate (MeJA), but not by 100 mg/L salicylic acid (SA) in the callus of C. acuminata. The complementation of CaHDR in Escherichia coli ispH mutant MG1655 demonstrated its function.