120 – Radioprotection of Irradiated Mice – Mechanisms and Synergistic Action of WR-2721 and R.L.B.

Authors : M. BELJANSKI
Deutsche Zeitschrift für Onkologie, 23, 6, 1991, pp. 155-159.

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ABSTRACT: Radioprotector WR-2721 (S-2 (3-amino-propylamino)-ethyl-phosphorothioic acid) includes in vitro the contraction of DNA chains, but only when these originate from normal cells. Chain contraction results in a decrease of UV absorbance at 260 nm (hypochromicity). A correlation exists between DNA hypercromicity induced by WR-2721 and decrease in the synthesis of the same DNAs used as templates in the presence of this radioprotector. In contrast, the compound has no effect either on secondary structure of DNAs from various cancer cells or on in vitro synthesis of these DNAs. In association with R.L.B. which selectively prime replication of DNAs from normal haematopoietic cells, WR-2721, used at ralatively low doses, protects mice against lethal doses of gamma radiation. Efficient survival rates are obtained. The mechanism of this protection by WR-2721 and R.L.B. is discussed.

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119 – Reverse Transcriptases in Bacteria: Small RNAs as Genetic Vectors and Biological Modulators

Authors : M. BELJANSKI
Brazil. J. Genetics, 14, 4, 1991, pp. 873-896.

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ABSTRACT: In 1970, with my group at the Pasteur Institute in Paris, I observed that showdomycin resistant Escherichia coli cells excrete into their culture medium a small RNA, about 160 nucleotides long, rich in purine bases. This RNA transforms wild bacteria (E. coli and Agrobacterium tumefaciens) into transformants which exhibit new stable biochemical and physical characteristics. Thus A tumefaciens once transformed by E. coli transforming RNA, partially or often totally loses its oncogenic potentialities and acquires new properties. It appeared that reverse transcriptase might give transforming RNA the means of integrating into the genome of the transformed organisms the modifications it vectored. We demonstrated (1971-1972) that bacterial reverse transcriptase was involved in this process. In the course of our studies on bacterial transformation, we devised a technique which led to the discovery, first of RNA free reverse transcriptase in bacteria, then of RNA-bound reverse transcriptase which is easily distinguishable from DNA-dependent-DNA-polymerase. In 1989 several american scientists rediscovered reverse transcriptase in E. coli.

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118 – RNA Fragments (RLB) and Tolerance of Cytostatic Treatments in Hematology: A Preliminary Study about Two Non-Hodgkin Malignant Lymphoma Cases

Authors : DONADIO, R. LORHO, J.E. CAUSSE, T. NAWROCKI, M. BELJANSKI
Deutsche Zeitschrift für Onkologie, 23, 2, 1991, pp. 33-35.

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ABSTRACT: Assays were carried out with short-chain RNA fragments in order to determine whether they can prevent or decrease chemotherapy-induced neutropenia and thrombopenia, as well as to evaluate side effects. We studied both first patients, 65 and 77 years old with non-Hodgkin lymphoma. The short-chain RNAs, administred bysublingual way every second day, appear useful in this indication. Neutrophils and platelets are significantly increased. In addition, tolerance of the RNA fragment is good and no side effect is observed. Chemotherapy protocols could be followed without treatment.

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117 – Cancer et Sida. Nouvelles approches thérapeutiques

Authors : M. BELJANSKI
5èmes Entretiens Internationaux de Monaco, 21-24 novembre 1990 (ed. du Rocher), pp. 25-37.

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ABSTRACT: La sélectivité d’action des substances est une notion aussi nouvelle que fondamentale. Alors que toutes les autres solutions jusqu’ici offertes sont brutales, toxiques (les médicaments s’incorporant souvent sans retour dans les gènes), est offert une alternative ciblée, de toute sécurité, multifocale afin que le virus soit détruit, l’immunité protégée et l’équilibre rétabli, seules conditions pour une vie de qualité se dirigeant jour après jour vers la “guérison”..

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115 – Résultats préliminaires de l’emploi des trois alcaloïdes sur des carcinomes prostatiques

Authors : M. BELJANSKI, M.S. BELJANSKI, M. GRANDI*
In Tumori, Institute Nationale per le studio ed la cura dei tumori (ed. Lambrosiana), Vol. 75, suppl. 4, 1989.
“Resultati preliminari dell’impiego di tre alcaloidi nel carcinoma prostatico”
*Dr. Maurizio GRANDI, membre de l’académie des sciences de Rome

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ABSTRACT: Nous avons étudié l’effet des alcaloïdes : Alstonine, Serpentime et Sempervirine, en association avec la radiothérapie sur 5 patients ayant un carcinome prostatique. Ces résultats confirment ceux déja obtenus en laboratoire sur la reconnaissance sélective du DNA néoplasique.

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114 – Neoplastic Characteristics of the DNA Found in the Plasma of Cancer Patients

Authors : M. STROUN, P. ANKER, P. MAURICE, J. LYAUTEY, C. LEDERREY, M. BELJANSKI
Oncology, 46, 1989, pp. 318-322.

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ABSTRACT: About one third of patients with various malignant diseases were found to have extractable amounts of DNA in their plasma whereas no DNA could be detected in normal controls. Using the test established by one of us (M.B.), which is based on decreased strand stability of cancer cell DNA, we have found that several plasma DNA originate from cancer cells.

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113 – Reversible biophysical changes of DNAs from in vitro cultured non-tumour cells

Authors : M. BELJANSKI, L. LE GOFF, M. WICKER
Med. Sci. Res., 16, 1988, pp. 359-361.

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ABSTRACT: We have previously shown that DNA fom plant Crown-gall tumour tissues is highly relaxed and thereby very susceptible to various DNA-destabilizing agents which, in contrast, do not affect DNA from healthy tissues. In vitro DNA strand separation (chain unpairing), the rate of in vitro DNA synthesis and in vivo increase in tumor cell multiplication are colsely correlated. Here we report that plant non-tumour cell DNA may temporarily undergo conformational changes when these cells are cultured in vitro in the presence of opines (octopine, nopaline, lysopine which accumulate in Crown-gall tissues or dl-ethionine (a known carcinogen in mammalian tissues). The induced DNA double-strand destabilisation and consequent increase in template activity are shown to be reversible under our experimental conditions.

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111 – Particular RNA primer from growth medium differentially stimulates in vitro DNA synthesis and in vivo cell growth of Neurospora crassa and its slime mutant

Authors : M. BELJANSKI, S.K. DUTTA
Current Genetics, 12, 1987, pp. 283-289

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ABSTRACT: Purine rich small “RNA-primer” molecules (about 10-12 nucleotides), secreted into the growth medium of 3-h germinated conidia of N. crassa, strongly stimulated a concentration-dependent in vitro DNA synthesis of N. crassa slime mutant as well as DNAs from the human cancer cells but did not affect that from normal cells. These “RNA-primer” molecules stimulated also in vivo cell growth of N. crassa slime mutant, but not of the N. crassa wild type. Our studies suggest that DNAs from the slime mutant of N. crassa as well as DNAs from human cancerous cells provide increased sites for enhanced in vitro and in vivo replication of DNAs. “RNA-primer” molecules can be hydrolyzed by T1 RNase but not by pancreatic RNase.

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110 – Differential Synthesis and Replication of DNA in the Neurospora crassa Slime Mutant versus Normal Cells: Role of Carcinogens

Authors : M. BELJANSKI, S.K. DUTTA
Oncology, 44, 1987, pp. 327-330

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ABSTRACT: Small quantities of carcinogens, dl-ethionine, thiotepa, actinomycin D, and 1-(2-chloroethyl-3-cyclohexyl)-1-nitrosourea (CCNU) stimulated in vitro deoxyribonucleic acid (DNA) synthesis of the slime mutant of Neurospora crassa, while there was practically no effect on the DNA from the normal wild type 74A strain. All of these compounds caused increased strand separation in the mutant DNA of N. crassa, but no separation of normal DNA strands. The growth (in vivo tests) of the N. crassa slime mutant, but not its wild type, was markedly increased when nontoxic concentrations of one of the carcinogens (dl-ethionine) tested were present in the growth medium. These observations suggest that, unlike the wild type N. crassa, the slime mutant allows an excessive and unscheduled replication, indicating destabilized nature of its DNA.

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109 – Terminal deoxynucleotidyl transferase and ribonuclease activities in purified hepatitis-B antigen

Authors : M. BELJANSKI
Med. Sci. Res., 15, 1987, pp. 529-530.

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ABSTRACT: Terminal deoxyribonucleotidyl transferase (TdT) (EC 2.7.7.31) was defined as a template independent DNA polymerase that binds deoxyribonucleoside-5′-monophosphates (dNMP) in sequential addition to the 3’OH end of the DNA initiator. TdT may exhibit its activity in the presence of oligodeoxyribopolymers. This enzyme has been found in embryonic calf thymus gland, cortical thymocytes, brain, primitive bone marrow cells, peripheral blood lymphocytes in certain forms of acute leukemia, neuroblastoma and retroviruses. A model was proposed according to which TdT may generate somatic mutations in the variable region of immunoglobulin genes. Recently, the mutagenic potential of TdT has been evaluated: TdT inserts noncomplementary bases during repair synthesis by DNA polymerase. The present work shows that purified and commercially available hepatitis-B antigen (vaccine) contains a very active TdT and ribonuclease (RNase).

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