PubMed Health⌕ Search

Biomedical subjects

R Monier

Publications and source records attributed to R Monier.

14 recordsLinked to original sources
PubMed1992

Metastatic phenotype of murine tumor cells expressing different cooperating oncogenes.

Four murine cellular tumor models expressing various combinations of oncogenes (SV40 large T and v-Ha-ras, SV40 large T and v-src, SV40 large T and neu, adenovirus EIA and v-Ha-ras) induce sarcoma when they are inoculated s.c. into the DBA/2 syngenic mice. The metastatic patterns, distribution and fate of these tumor cells transplanted by two different routes into syngenic DBA/2 mice have been studied. All the tumor cell lines except EIA-ras, induce massive overt artificial metastases principally in the lung after i.v. injection. In s.c. tumor-bearing mice, a few resting cells colonize the lung as micrometastases. When removed from this tissue context and injected s.c. these cells regain their proliferative potential and grow as local tumors which again give rise to occult pulmonary micrometastases.

Adenovirus Early Proteins↗
PubMed1991

gsp mutations in human thyroid tumours.

The presence of gsp mutations at codons 201 and 227 in the gene coding for the alpha subunit of the GTP-binding Gs protein which stimulates adenylyl cyclase (AC) has been investigated in 31 samples of differentiated thyroid tumours, which had been previously characterized with respect to their adenylyl cyclase activity (ACA) before and after stimulation by thyroid-stimulating hormone (TSH). Polymerase chain reaction (PCR) amplification of DNA extracted from these tumours, followed by high stringency oligonucleotide probing, enabled the detection of mutations in three samples originating from tumours with high constitutive ACA, which was not significantly further stimulated by TSH. Two mutations were at codon 227 and replaced Gln227 by His or Lys, and one was at codon 201, with the substitution of Arg201 by Ser. Because thyrocytes belong to the subset of differentiated cells which are programmed to proliferate in response to elevated cAMP levels, the gsp mutations observed in some differentiated thyroid carcinomas probably contributed to their tumorigenic phenotype.

Adenocarcinoma↗
PubMed1991

[Conclusion and future prospects].

The genetic events which are associated with tumorigenesis concern two classes of genes: proto-oncogenes and anti-oncogenes. The first code for products which take part in the positive control of cellular proliferation; the second code for products which are involved in the negative regulation of cell growth. The identification of genes involved in the genetic predisposition to some cancers can be used in predictive medicine, while the observations on proto-oncogenes are already of prognostic value in some instances. In the future they will lead to new therapeutic approaches.

Cell Cycle↗
PubMed1990

Oncogenes and anti-oncogenes in tumorigenesis.

Recent advances have led to the identification of cellular genes which are involved in the initiation and progression of tumorigenesis. The proto-oncogenes, which normally participate in the regulation of cell proliferation and differentiation, can become oncogenes through alterations in the regulation of their expression and/or their coding sequences. Their contribution to the tumorigenic phenotype is dominant. The anti-oncogenes or tumor suppressor genes or recessive oncogenes are normally implicated in a negative regulation of cellular proliferation. The loss of their activity contributes to tumorigenesis in a recessive manner. Genetic events activating proto-oncogenes or inactivating anti-oncogenes accumulate in the same cell during tumor progression and co-operate to determine the malignant invasive phenotype of advanced tumors.

Cell Differentiation↗
PubMed1990

Presence of mutations in all three ras genes in human thyroid tumors.

Polymerase chain reaction (PCR) amplification followed by oligonucleotide probing was used to investigate the presence of ras genes mutations in human thyroid adenomas and carcinomas. The results confirm the frequent occurrence of mutations in all three ras genes in both adenomas and carcinomas, in agreement with the hypothesis that the ras mutations may constitute early steps in thyroid tumorigenesis. No evident correlation between the frequency of ras mutations, the identity of the mutated ras gene, the position affected in the ras gene or the type of mutation and the pathological features is apparent. However, definitive conclusion on this point is precluded because of the small number of tumors examined at the present time.

Adenoma↗
PubMed1979

Oncogenic transformation of rat lung epitheloid cells by SV 40 DNA and restriction enzyme fragments.

Rat epitheloid lung cells were transformed with various preparations of SV40 dna using the Ca2+-precipitation technique. The amount of SV40 genetic information integrated into transformed clones was evaluated by DNA-DNA renaturation kinetics. The growth properties on plastic and in soft-agar were examined, as well as the ability to induce tumors in syngeneic new-born animals or in adult nude mice. One particular transformed line, which had received the Hpa II/BamH I A (59 per cent) fragment, was found to contain about 3 integrated copies of this fragment per cell and no significant amount of the Hpa II/BamH I B (41 per cent) fragment. This line which grew to high saturation densities and efficiently formed clones in low serum on plastic, produced tumors in both syngeneic rats and nude mice. Thus the Hpa II/BamH I A fragment, which mainly includes early viral information, was sufficient to impart these properties to rat epitheloid lung cells.

Animals↗
PubMed1978

Viable deletion mutants in the simian virus 40 early region.

For the purpose of isolating hr-t-like mutants of simian virus 40, we have constructed variants that have lost the unique site for the restriction enzyme Taq I at 0.565. Five mutants have been isolated and characterized by restriction enzyme analysis. All of them produce a normal size T antigen. Four produce a t antigen reduced in size as well as in amount; the fifth one does not seem to make any t antigen at all. The ability of these mutants to transform mouse cells in vitro, as tested by anchorage dependence, is clearly altered; however, the defect is only partial. In the same test, the mutants can complement a tsA mutant for transformation and therefore define a second complementation group in the simian virus 40 early region.

Antigens, Viral↗
PubMed1978

Presence of free viral DNA in simian virus 40-transformed nonproducer cells.

Extracts from several simian virus 40 (SV40)-transformed nonproducer cells were prepared by the hot-phenol procedure normally used to extract cellular RNA. These extracts contained SV40 infectious units. Part of the infectious units were identified as SV40 form I DNA molecules. The results of reconstruction experiments suggest that SV40 form I DNA is extractable by the hot-phenol procedure because of its fast renaturation rate. The significance of the presence of free viral DNA in nonproducer transformed cells is discussed.

Animals↗
PubMed1975

[Neuroskeletal radiography and relationships of the sensitive branch of the radial nerve].

The authors carried out an anatomical, roentgenological and surgical study of the ramus superficialis of the radial nerve in man. This branch springs down 1,2 cm. below the humeroradial space and crosses the posterior rim of brachioradialis 8 cm. above the tip of the radial processus styloideus. Twice the exceptional arteria antebrachialis dorsalis was found; the vessel and the radial nerve looked like a posterior pedicle at the forearm. Among the 3 ending branches, the middle one is the most vulnerable in lateral approach of radius and naviculare.

Fetus↗