The Foundational Studies Of Anticancer Active Substance In CDA-Ⅱ

The malignant tumor cells resemble undifferentiated embryonic cells either on the form, function or on the metabolism. The differentiation-inducing agent renders to transform the biological and immunological characteristics of tumor cells to normal status. It is discovered that the synthesis of de-methyl DNA is one of the key factors during the course of proliferation and ultimate differentiation, and the activity of Methionine Adenosyltransferase complex (MATc) is abnormally active, as a result, the synthesis of de-methyl DNA is blocked leading to the unlimited proliferation of cells.CDA-II is a mixture isolated form urea of healthy body by the process of acidification, resin adsorption, ethanol elution and purification. The major components include small molecular peptide, amino acids and organic acids. As a cell differentiation-inducing agent, CDA-II inhibits the activity of MTs to induce the tumor cells to synthesize de-methyl DNA, and urge the differentiation of cells in the end. It is confirmed in lab that CDA-II possesses evident effect to inhibit the growth and to induce differentiation of cells.It is proved that CDA-II act directly on the abnormal MATc. The most noticeable differentiation-inducing agents at present such as retinoic acid, interferon, vitamine D3, methylene diamide, DMSO, phorbol ester and so on belong to indirect differentiation-inducing agents. Both kinds of agents possess a common bioactivity to induce the tumor cells to produce oligo-isonucleotide whose effect is similar to that of CDA-II. However, the tumor cell lines that indirect differentiation-inducing agent can influence is too limited, and the result of inducing differentiation depends on the amount of receptor of thus agents on tumor cells;in reverse, CDA-II have a wide spectrum and is not limited by receptor, which assign it a extensive prospects.Urea is a convenient and economic resourses which possess the features of low cost, wide space of useness, high economic value and rich in bioactive peptides. At present, there are many problems about the studies of CDA-II. For one thing, the conventional sepatative methods are not suitable to obtain the single component because of the instability to temperature, oxidantagents and metal ions of small molecular peptides and high polarity and low resolution on HPLC: For another, as a result of the similarity in the structure of the components and difficult isolation and identification, the components analysis is always the results of methods of trace quality such as LC-MS. To take a wide view on the recent development of CDA-II, most studies focuses on the total matters isolated. The reliable analysis and activity assay of the component singly have never been reported or published in detail, which influences other work such as formulation of quality standard.The major purpose in this topic is to study fundationally the substance with anticancer activity in CDA-II and to report the primary components of this novel cell differentiation-inducing agent and to provide with evidence for further development. In this thesis, what is introduced in turn are the thereaputic histories and current status of cancer, preparation of CDA-II, the isolation and analysis and sutructure identification of the major chemical compenents, the extraction technology of partial organic acids, activity assay with some tumor cell strains, discussion of the process of experiment, the current status of CDA-II research and the further research direction. In the section of discussion, the problems about the experiments and the questions unsolved are summarized to offer an object in view in the research work afterwards and to reduce the emergence of the unnecessary fault.As the components in CDA-II are complex and are difficult to isolate and purify, some advanced apparatus such as HPLC, preparative LC, and LC-MS are applied under the circumstance of unsatisfactory results with conventional separative methods. The suitable experimental condition is reported to better analyze the chemical components in CDA-Ii. Judging from the preliminary analysis results, there are about more than 20 small molecular peptides, dozens of kinds of organic acids, and partial amino acids in CDA-II. The results of study display some pleasant discoveries though the study on these chemical composition still awaits deepening and only part components are performed activity assay and await perfect further yet. The comparison of the antitumor activity of chemical composition and relevant component parts in the result of study offer relevant bases to optimization research of preparation formulation, quality standard formulation, production technology improvement and further development of CDA-II.