• Plant Biotechnology Reports
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• 제2권1호
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• pp.87-92
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• 2008

An improved protocol for high frequency plant regeneration via somatic embryogenesis from zygotic embryo-derived cell suspension cultures of watershield (Brasenia schreberi) was developed. Zygotic embryos formed pale-yellow globular structures and white friable callus at a frequency of 80% when cultured on halfstrength MS medium supplemented with $0.3mg\;l^{-1}$ 2,4-D. However, the frequency of formation of pale-yellow globular structures and white friable callus decreased slightly with increasing concentrations of 2,4-D up to $3mg\;l^{-1}$, where the frequency reached ~50% of the control. Cell suspension cultures from zygotic embryoderived white friable callus were established using half-strength MS medium supplemented with $0.3mg\;l^{-1}$ 2,4-D. Upon plating of cell aggregates on half-strength MS basal medium, approximately 8.3% gave rise to somatic embryos and developed into plantlets. However, the frequency of plantlet development from cell aggregates was sharply increased (by up to 55%) when activated charcoal and zeatin were applied. Regenerated plantlets were successfully transplanted to potting soil and grown to normal plants in a growth chamber. The distinctive feature of this study is the establishment of a high frequency plant regeneration system via somatic embryogenesis from zygotic embryo-derived cell suspension cultures of water-shield, which has not been previously reported. The protocol for plant regeneration of watershield through somatic embryogenesis could be useful for the mass propagation and transformation of selected elite lines.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1898-1906
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• 2004

Nonclassical quinazolinone analogs I, II, and III, in which the glutamic acid moiety of the classical antifolates is substituted by phenylglycine, phenylalanine or aminobenzoic acid and their methyl esters, were synthesized and evaluated as lipophilic inhibitors of thymidylate synthase (TS). The target compounds were generally potent inhibitors of L. casei and human TS with $IC_{50}$ values within the narrow range of 0.2-10 ${\mu}$M and 0.003-0.03 ${\mu}$M, respectively. Further, most of the target compounds showed cytotoxicity against tumor cell lines of murine and human origin with $IC_{50}$ values of as low as 0.050 ${\mu}$M. Substitution of another hydroxyl or carboxylic acid/ester group at the phenyl ring further increased the potency of TS inhibition and cell growth inhibition. Most effective were compounds If and Ic in which extra carboxylic acid/ester was present at the phenyl ring with nanomolar $IC_{50}$ values of 0.0044 and 0.0093 ${\mu}$M against human TS and submicromolar cytotoxic growth inhibition against all four tumor cell lines.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.2151-2157
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• 2016

Scabraside D, a sulfated triterpene glycoside, was extracted from the sea cucumber Holothuria scabra. It shows anti-proliferation in many of cancer cell lines, but the function and mechanisms of action of scabraside D in human cholangiocarcinoma (HuCCA) have not previously determined. In this study, we investigated the activity of scabraside D on HuCCA cell apoptosis, lymphangiogenesis and metastasis in a nude mouse model. Scabraside D induced signs of apoptosis, such as cell shrinkage, nuclear condensation, nuclear fragmentation and DNA fragmentation on TUNEL assays, while effectively decreasing expression of BCl-2 but increasing caspase-3 gene level expression. Immunohistochemistry revealed that scabraside D significantly reduced lymphatic vessel density (LVD). Moreover, scabraside D treatment significantly decreased VEGF-C, MMP-9 and uPA gene expression, which play important roles in the lymphangiogenesis and invasion of cancer cells in metastasis processes. Quantitative real-time PCR showed that scabraside D significantly decreased iNOS and STAT-3 gene expression. This study demonstrated that scabraside D plays a role in activation of HuCCA tumor apoptosis and inhibition of lymphangiogenesis, invasion and metastasis through decreasing BCl-2, MMP-9, uPA and VEGF-C and increasing caspase-3 expression by suppression of iNOS and STAT-3 expression. Therefore, scabraside D could be a promising candidate for cholangiocarcinoma treatment.

• Natural Product Sciences
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• 제10권6호
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• pp.335-340
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• 2004

The chromatographic separation of the MeOH extract of the aerial parts from Aster hispidus (Compositae) led to the isolation of eight compounds. Their structures were established by spectroscopic methods to be ${\beta}-amyrin$ (1), oleanolic acid (2), (2R)-1, 2-O-(9Z, 12Z, $15Z-dioctadecatrienoyl)-3-O-{\beta}-D-galactopyranosyl\;glycerol$ (3), trans-phytol (4), 9, 12, 15-octadecatrienoic acid (5), kaempferol (6), 3,5-dicaffeoyl quinic acid (7), 3,4-dicaffeoyl quinic acid (8) and kaempferol-3-O-rutinoside (9). Compounds 1, $3{\sim}6$ and 9 showed non-specific moderate cytotoxicity against five human tumor cell lines $(5.44{\sim}23.51\;{\mu}g/ml)$. The other compounds were of marginal activity against tested five human cancer cell lines $(9.05{\sim}>30.0\;{\mu}g/ml)$.

• The Korean Journal of Physiology and Pharmacology
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• 제17권3호
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• pp.237-243
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• 2013

B13 is a ceramide analogue and apoptosis inducer with potent cytotoxic activity. A series of arylpropyl sulfonamide analogues of B13 were evaluated for their cytotoxicity using MTT assays in prostate cancer PC-3 and leukemia HL-60 cell lines. Some compounds (4, 9, 13, 14, 15, and 20) showed stronger activities than B13 in both tumor cell lines, and compound (15) gave the most potent activity with $IC_{50}$ values of 29.2 and 20.7 ${\mu}M$, for PC-3and HL-60 cells, respectively. Three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis was performed to build highly reliable and predictive CoMSIA models with cross-validated $q^2$ values of 0.816 and 0.702, respectively. Our results suggest that long alkyl chains and a 1R, 2R configuration of the propyl group are important for the cytotoxic activities of arylpropyl sulfonamides. Moreover, the introduction of small hydrophobic groups in the phenyl ring and sulfonamide group could increase biological activity.

• Mycobiology
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• 제51권2호
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• pp.94-108
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• 2023

Termitomyces sp. that grow in symbiosis with fungus-farming Termites have medicinal properties. However, they are rare in nature, and their artificial culture is challenging. The expression of AXL receptor tyrosine kinase and immune checkpoint molecules favor the growth of cancer cells. The study evaluated the optimal conditions for the artificial culture of Termitomyces and their inhibitory activity on AXL and immune checkpoint molecules in lung adenocarcinoma and melanoma cell lines. The culture of 45 strains of Termitomyces was compared. Five strains with marked growth rates were selected. Four of the selected strains form a single cluster by sequence analysis. The mycelium of 4 selected strains produces more fungal mass in potato dextrose broth than in a mixed media. The bark was the most appropriate solid substrate for Termitomyces mycelia culture. The mycelium of all five selected strains showed a higher growth rate under normal CO₂ conditions. The culture broth, methanol, and ethyl acetate of one selected strain (T-120) inhibited the mRNA relative expression of AXL receptor tyrosine kinase and immune checkpoint molecules in cancer cell lines. Overall, these results suggest the potential usefulness of Termitomyces extracts as a coadjuvant therapy in malignant diseases.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.355-362
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• 2014

Objective: Altered regulation of many transcription factors has been shown to play important roles in the development of leukemia. hMSH2 can modulate the activity of some important transcription factors and is known to be a regulator of hematopoietic differentiation. Herein, we investigated epigenetic regulation of hMSH2 and its influence on cell growth and overall survival of acute lymphoblastic leukemia (ALL) patients. Methods: hMSH2 promoter methylation status was assessed by COBRA and pyrosequencing in 60 ALL patients and 30 healthy volunteers. mRNA and protein expression levels of hMSH2, PCNA, CyclinD1, Bcl-2 and Bax were determined by real time PCR and Western blotting, respectively. The influence of hMSH2 on cell proliferation and survival was assessed in transient and stable expression systems. Results: mRNA and protein expression of hMSH2 and Bcl-2 was decreased, and that of PCNA, CyclinD1 and Bax was increased in ALL patients as compared to healthy volunteers (P<0.05). hMSH2 was inactivated in ALL patients through promoter hypermethylation. Furthermore, hMSH2 hypermethylation was found in relapsed ALL patients (85.7% of all cases). The median survival of patients with hMSH2 methylation was shorter than that of patients without hMSH2 methylation (log-rank test, P=0.0035). Over-expression of hMSH2 in cell lines resulted in a significant reduction in growth and induction of apoptosis. Conclusions: This study suggests that aberrant DNA methylation and epigenetic inactivation of hMSH2 play an important role in the development of ALL through altering cell growth and survival.

• The Plant Pathology Journal
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• 제26권2호
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• pp.154-158
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• 2010

Early nematode development and subcellular responses in resistant soybean lines PI 88788 and PI 437654 infected with races 3 (R3) and 14 (R14) of soybean cyst nematode (SCN), Heterodera glycines Ichinohe, were compared. SCN R14 nematodes penetrated and developed significantly more than R3 at 5-6 days after inoculation. Both races also penetrated and developed more in PI 88788 than in PI 437654. Syncytia, characterized by cell wall dissolution and cellular hypertrophy, were developed more in PI 88788 than in PI 437654 and more by R14 than R3, for which less necrotic responses occurred in the former than the latter. This suggests that the latter two may be more resistant and less virulent than the former two, respectively. A common structural feature found in each of PI 437654 and PI 88788 in relation to SCN-resistance was the formation of prominent cell wall appositions and nuclear degeneration prior to cytoplasmic degradation in syncytial cells, respectively. Necrosis and cell wall apposition are types of hypersensitive responses occurring at early stages of the nematode infection so that these structural modifications indicate the inhibition of initial syncytial development related to the early nematode development. As soybean cultivars and lines with identical or similar genotypes have the same types of structural features related to SCN-resistance, the structural modifications induced by SCN infection may result from the expression of inheritable resistance genes, of which the information can be used for breeding soybean cultivars and lines specifically resistant to SCN races.

• 한국전자파학회논문지
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• 제16권2호
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• pp.149-153
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• 2005

본 논문에서는 Compact Microstrip Resonant Cell을 이용하여 새로운 방법으로 선형성을 개선시킨 전력증폭기를 설계하였다. 전력증폭기의 입력단에 CMRC를 적용하였고, 입력단과 출력단에 각각 Tuning Line을 달아서 조정을 한 결과 기존의 전력증폭기보다 현저한 선형성을 보였다. 그 결과 CMRC를 적용한 전력증폭기는 기존의 전력증폭기보다 3차 IMD가 14.77 dB 만큼 개선되었다. CMRC의 크기는 $17.1\times5.22mm$이다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.2975-2979
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• 2015

Background: Telomere length is closely associated with cellular radiosensitivity and WRAP53 is required for telomere addition by telomerase. In this research we assessed radiosensitivity of laryngeal squamous cell carcinoma Hep-2 cell lines after WRAP53 inhibition, and analyzed the molecular mechanisms. Materials and Methods: phWRAP53-siRNA and pNeg-siRNA were constructed and transfected into Hep-2 cells with lipofectamine. Expression of WRAP53 was analyzed by RT-PCR and Western-blottin, radiosensitivity of Hep-2 cells was assessed colony formation assay, and the relative length of telomeres was measured by QPCR. Results: The data revealed that the plasmid of phWRAP53-siRNA was constructed successfully, and the mRNA and protein levels of WRAP53 were both obviously reduced in the Hep-2 cell line transfected with phWRAP53-siRNA. After Hep-2 cells were irradiated with X-rays, the $D_0$ and $SF_2$ were 2.481 and 0.472, respectively, in the phWRAP53-siRNA group, much lower than in the control group ($D_0$ and $SF_2$ of 3.213 and 0.592) (P<0.01). The relative telomere length in the phWRAP53-siRNA group was $0.185{\pm}0.01$, much lower than in the untreated group ($0.523{\pm}0.06$) and the control group ($0.435{\pm}0.01$). Conclusions: Decreasing the expression of WRAP53 using RNA interference technique can enhance the radiosensitivity of Hep-2 cell lines by influencing the telomere length. WRAP53 is expected to be a new target to regulate the radiosensitization of tumor cells.