Current Drug Discovery Technologies

ISSN: 1570-1638


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Contents


Immunofluorescence and Immunoelectron Microscopic Localization of Medicinal Substance, Rb1, in Several Plant Parts of Panax ginseng, 2011, 8, 51-59
Sadaki Yokota, Yuko Onohara and Yukihiro Shoyama
[Abstract] [Full Text Article]


Preparation of Knockout Extract for Determination of Really Active Compound Using MAb, 2011, 8, 16-23
Takuhiro Uto, Indree Tuvshintogtokh and Yukihiro Shoyama
[Abstract] [Full Text Article]


Versatile Applications of microRNA in Anti-Cancer Drug Discovery: From Therapeutics to Biomarkers, 2010, 7, 95-105
Haruhisa Iguchi, Nobuyoshi Kosaka and Takahiro Ochiya
[Abstract] [Full Text Article]


Using Pharmacologic Data to Plan Clinical Treatments for Patients with Peritoneal Surface Malignancy, 2009, 6, 72-81
Kurt Van der Speeten, Oswald Anthony Stuart and Paul H. Sugarbaker
[Abstract] [Full Text Article]



Abstracts

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Immunofluorescence and Immunoelectron Microscopic Localization of Medicinal Substance, Rb1, in Several Plant Parts of Panax ginseng
Sadaki Yokota, Yuko Onohara and Yukihiro Shoyama
[Full Text Article]

It is important to know the localization of medicinal substance, Rb1, of Ginseng, Panax ginseng, in this plant in order to achieve efficient extraction of Rb1 or to culture producing cells. In this report, we describe the localization of Rb1 in various parts of the plant as determined by immunofluorescence (IF) and immunoelectron microscopies (IEM). Using IF, we show that Rb1 is localized to chloroplasts, peroxisomes and cytoplasm but not to vacuoles of leaf parenchymal cells. In the leaf stem, Rb1 is localized to the vascular bundles as well as vacuoles. In the root, vacuoles of parenchymal cells are stained at various intensities. Using IEM, gold particles showing Rb1 antigenic sites are present in the compartments stained by IF technique. In addition, Rb1 is localized in the sieve elements of the phloem and degrading primary cell wall of xylem, and in the root parenchymal cells Rb1 is associated with electron dense polymorphic materials but not in starch granules. Translocation and storage of Rb1 and effective utilization of leaves are discussed.


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Preparation of Knockout Extract for Determination of Really Active Compound Using MAb
Takuhiro Uto, Indree Tuvshintogtokh and Yukihiro Shoyama
[Full Text Article]

The crude-rhizome extract of P. japonicus was loaded on the immunoaffinity column conjugated with antiginsenoside- Rb1 monoclonal antibody (MAb) and washed with the washing solvent, followed by elution solvent, to give fraction 2 containing higher concentration of compound 1. Compound 1 clearly indicated a dammarane saponin having protopanaxadiol as a framework and three sugars in a molecule suggesting that compound 1 is chikusetsusaponin III. Compound 2 was also determined as chikusetsusaponin VI compared to the staining color, its Rf value and the comparison with ginsenoside Rb1. We succeeded in one step purification of ginsenoside-Rb1 by immunoaffinity column conjugated with anti- ginsenoside-Rb1 MAb leading to the knock-out extract which will be useful for pharmacological investigation. The antibody was stable when exposed to the eluent, and the immunoaffinity column showed almost no decrease in capacity after repeated use more than 10 times under the same conditions. From the crude extract of licorice we isolated glycyrrhizin by one-step purification by the immunoaffinity column using anti-glycyrrhizin MAb. Washing fraction contained all components except for only glycyrrhizin and was named as the knockout extract. We confirmed the synergic effect of glycyrrhizin with some other components for the inhibition of nitric oxide (NO) production by blocking inducible nitric oxide synthase (iNOS) expression by using its knockout extract.


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Versatile Applications of microRNA in Anti-Cancer Drug Discovery: From Therapeutics to Biomarkers
Haruhisa Iguchi, Nobuyoshi Kosaka and Takahiro Ochiya

[Full Text Article]

Over the past several years, microRNAs (miRNAs) have been identified as a fine-tuner in a wide array of biological processes, including development, cell growth and metabolism. Recent studies have shown that many kinds of miRNAs act as oncomirs or tumor suppressors in tumors where the miRNA genes are up- or down- regulated, respectively. These dysregulations occur through a variety of mechanisms, such as genetic alterations, epigenetic repression or altered expression of transcription factors which target miRNAs. The aberrant expressions of miRNAs are observed not only in tumor lesions but also in plasma and serum of cancer patients. These characteristics of miRNAs have created extensive interest in tapping into them for diagnosis and prognosis as well as drug discovery in cancer therapy.

In this literature, the significance of miRNAs in tumor initiation and development is first reviewed. Second topic is ex-tracellular miRNAs as biomarkers for cancer classification and prediction. Further, we focus on secretory machinery of miRNAs and share new evidence suggesting that extracellular miRNAs can play biological roles beyond mere biomarkers. Extending this concept, our hypothetical model that extracellular miRNAs may function as a signaling molecule in a crosstalk between cancer cells and their surrounding cells is presented. Finally, we discuss the potential of miRNAs for therapeutic applications in clinical oncology.


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Using Pharmacologic Data to Plan Clinical Treatments for Patients with Peritoneal Surface Malignancy
Kurt Van der Speeten, Oswald Anthony Stuart and Paul H. Sugarbaker

[Full Text Article]

The surfaces of the abdomen and pelvis are an important anatomic site for the dissemination of gastrointestinal and gynecologic malignancy. This transcoelomic spread of cancer cells gives rise to peritoneal carcinomatosis which, without special treatments, is a fatal manifestation of these diseases. In order to control peritoneal carcinomatosis cytoreductive surgery to remove gross disease is combined with perioperative intraperitoneal and perioperative intravenous chemotherapy to eradicate microscopic residual disease. Chemotherapy agents are selected to be administered by the intraperitoneal or intravenous route based on their pharmacologic properties. A peritonealplasma barrier which retards the clearance of high molecular weight chemotherapy from the peritoneal cavity results in a large exposure of small cancer nodules on abdominal and pelvic surfaces. Tissue penetration is facilitated by moderate hyperthermia (41-42°C) of the intraperitoneal chemotherapy solution. A constant dose of chemotherapy agent and volume of carrier solution based on body surface area allows prediction of systemic drug exposure and systemic toxicity. Timing of the chemotherapy as a planned part of the surgical procedure to maximize exposure of all peritoneal surfaces is crucial to success.