The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
Michio Ogawa - One of the best experts on this subject based on the ideXlab platform.
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Immunohistochemical expression of the c-kit proto-oncogene product in human malignant and non-malignant breast tissues.
British Journal of Cancer, 1996Co-Authors: X Chui, Hiroshi Egami, J Yamashita, Takashi Kurizaki, H Ohmachi, Shinichi Yamamoto, Michio OgawaAbstract:The immunohistochemical expression of c-kit proto-oncogene product in 57 breast cancer tissues was studied using anti-c-kit proto-oncogene product antibody in comparison with 20 normal breast tissues and 58 benign breast tumours. In normal breast tissues, the c-kit proto-oncogene product was strongly expressed on cell membrane and/or cytoplasm of alveolar and ductal cells. The immunoreactive score (IRS) of c-kit proto-oncogene product in normal mammary epithelia was 6.22 +/- 2.11 (mean +/- s.d.). In benign breast diseases, the c-kit proto-oncogene product was detected heterogeneously with a reduced IRS (3.33 +/- 2.44). In breast cancer tissues, the expression of the immunoreactive c-kit proto-oncogene product was often deleted and the average IRS was significantly reduced compared to those of normal breast tissues or benign breast diseases tissues. Among benign diseases, the average IRS of intraductal papilloma was significantly reduced (1.34 +/- 1.70) and the staining intensity and pattern were found to be similar to those seen in breast cancer. The results in this study suggested that the c-kit proto-oncogene product is correlated with the growth control or the differentiation of normal breast epithelium. Also, the loss of the expression of this protein may indicate the change of the signal transduction in relation to malignant transformation in human mammary epithelium.
Sei Hyun Ahn - One of the best experts on this subject based on the ideXlab platform.
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The meaning of the c-kit proto-oncogene product in malignant transformation in human mammary epithelium.
Clinical & Experimental Metastasis, 2003Co-Authors: Jee Soo Kim, Byung Ho Son, Hee Joon Kang, Ho Sung Yoon, Eun Yoon Cho, Gyungyub Gong, Sei Hyun AhnAbstract:To evaluate the relationship between the c-kit proto-oncogene product and malignant transformation of human breast tissue, we examined the immunohistochemical expression of the c-kit proto-oncogene product in both malignant and non-malignant breast tissues. The immunohistochemical expression of the c-kit proto-oncogene product in 40 primary breast cancer tissues (22 axillary lymph nodes negative, 18 lymph nodes positive), in 18 corresponding axillary lymph nodes, and in 10 distant metastastic tissues were studied using an anti-c-kit proto-oncogene product antibody in comparison with 20 normal and 20 benign breast tissues. The mean values of immunoreactive score (IRS) were compared. The IRS of the c-kit proto- oncogene product in normal mammary epithelia was 5.90±1.37 (mean ± s.d.). In benign tissues, the c-kit proto-oncogene product was detected heterogeneously with a reduced IRS (4.05±1.82). In primary breast cancer tissues, the expression of the c-kit proto-oncogene product was often deleted and the average IRS (0.90±1.73) was significantly reduced compared to those of the normal breast tissues or benign breast disease tissues, but no significant difference was shown between the breast cancer groups. The c-kit proto-oncogene product may correlate with growth control or the differentiation of normal breast epithelium. This result suggests that the loss of expression of this protein might correlate with malignant breast cancer progression, but it is most likely involved at an early stage of human breast cancer development.
Maisonpierre Peter C - One of the best experts on this subject based on the ideXlab platform.
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Proto-Oncogenes and signaling processes in neural tissues.
Neurochemistry international, 1993Co-Authors: Marius Sudol, Seth G. N. Grant, Maisonpierre Peter CAbstract:Abstract The study of ubiquitously expressed Proto-Oncogenes or tumor suppressor genes provided important insights into the second messenger signaling pathways common to neural and non-neural tissues. Therefore, it is expected that the analysis of Proto-Oncogenes expressed in neural tissues should probe into neurotrophic and neurotransmitter receptors, ion channels and other molecules involved in processes underlying basic physiological functions of the nervous system. This expectation is fulfilled by ample experimental evidence. Using the trk, abl and src families of tyrosine kinase encoded Proto-Oncogenes, we discuss here new insights into the structural and functional organization of neural tissues gained from the molecular and genetic analyses of these genes and their products. Special attention is given to the description of initial steps of signaling through the Trk receptors in response to neurotrophic factors of the Nerve Growth Factor family. The genetic analysis of the Drosophila abl gene product identified new gene products that interact with the Abl protein. This analysis illuminates the power of Drosophila genetics in dissecting components of a signal transduction pathway. The Src-family of non-receptor type protein-tyrosine kinases is discussed from the point of functional redundancy as revealed by targeted gene disruption and expression studies. The recent progress in the field of Proto-Oncogenes has been impressive and it is expected that Proto-Oncogenes will continue to provide valuable tools in the study of the complex signaling pathways that underlie the physiological functions of the central nervous system.
Bertrand Nadel - One of the best experts on this subject based on the ideXlab platform.
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V(D)J targeting mistakes occur at low frequency in acute lymphoblastic leukemia.
Genes Chromosomes and Cancer, 2009Co-Authors: Katrina Vanura, Maruska Marusic Vrsalovic, Rodrig Marculescu, Rajko Kusec, Ulrich Jäger, Bertrand NadelAbstract:Translocations of Proto-Oncogenes to the B-cell or T-cell antigen receptor loci in acute T- or B-cell leukemia and lymphoma have been, in most cases, accredited to V(D)J or switch recombination depending on the location of the breakpoint at the receptor locus. Only in rare instances, the reports take into account mechanistic characteristics of the translocation mechanism. To assess the functional ability of several sites implicated in supposedly V(D)J-mediated translocations, we tested five sites at four proto-oncogene loci in an ex vivo recombination substrate assay for their potential to act as direct target for V(D)J recombination. Our results show that the LMO2/RBTN2/TTG2 site and one LCK/P56 site readily engage in recombination with a genuine TCR element with the majority of breakpoint junctions showing the characteristics of V(D)J recombination, which strongly supports the involvement of this mechanism in the pathogenesis of the corresponding translocations in vivo. The site at the TLX1/HOX11 locus yielded 0.8% V(D)J-specific junctions. Sites at the LCK/P56 and TCF3/E2A Proto-Oncogenes resulted in exclusively unspecific breakpoints scattered over part of or the entire proto-oncogene region tested, marking them as unlikely V(D)J recombination targets. Our data suggest that, while being a potentially dangerous mechanism due to the introduction of DNA breaks, V(D)J recombination is a tightly controlled mechanism allowing for only few direct mistakes.
Stanislas Lyonnet - One of the best experts on this subject based on the ideXlab platform.
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A novel polymorphism in the coding sequence of the human RET proto-oncogene
Human Genetics, 1994Co-Authors: Patrick Edery, Tawab Attie, Anna Pelet, Lois M. Mulligan, Arnold Munnich, Bruce A.j. Ponder, Stanislas LyonnetAbstract:A novel polymorphism in the coding sequence of the human RET proto-oncogene is described. The RET proto-oncogene maps to chromosome 10q11.2, and is involved in multiple endocrine neoplasia (MEN 2A, MEN 2B), familial medullary thyroid carcinoma and Hirschsprung's disease.
