The human bcl-6 proto-oncogene has been found to be mutated in both neoplastic and normal B cells. We used CL-01 cells, our monoclonal model of germinal center differentiation, and normal human B cells to explore the induction requirements and the modalities of bcl-6 hypermutation. As we have previously shown, CL-01 cells are IgM+ IgD+ and effectively mutate the expressed Ig VHDJH and V lambda ...

meduiiary thyroid carcinoma (mtc) occurs both sporadically and in the autosomal dominantly inherited multiple endocrine neoplasia (men) type 2 syndromes. the distinction between true sporadic mtc and a new mutation familial case is important for future clinical management of both the patient and family. the susceptibility gene for hereditary mtc is the ret proto-oncogene. dna analysis for germl...

Tumour suppressor genes may have a role in the control of trophoblast cell population expansion as trophoblast invasion occurs. To investigate this hypothesis, the location of tumour suppressor gene and proto-oncogene products were studied at various stages of trophoblast differentiation and invasion. Trophoblast and decidua were obtained from eight women having a therapeutic termination of pre...

Past studies have shown that serum-free cultures of PC12 cells are a useful model system for studying the mechanisms of neuronal death after neurotrophic factor deprivation. These cultures, as well as NGF-deprived cultures of sympathetic neurons, manifest and endonuclease activity that leads to "apoptotic" internucleosomal DNA cleavage. Overexpression of the proto-oncogene bcl-2 blocks apoptoti...

well as allelic deletions ofgenes on chromosomes 11 or 13 (9, 10). The frequency and level of amplification of c-myc and c-erbB-2 proto-oncogenes vary between different groups of patients studied by different laboratories. Amplification of c-erbB-2 was reported in 10, 16, 18, and 40% of breast tumors from different groups of patients (2, 5-8). In one study this proto-oncogene was suggested as a...

近年アポトーシスの研究があらゆる分野で進歩し, これらの研究によりアルツハイマー病にみられる神経 細胞死やAIDSによるT細胞の減少もアポトーシス の亢進,逆に自己免疫疾患や癌はアポトーシスの抑制 によるという病態の解明がなされ,さらに治療にも貢 献してきた.そして癌細胞においてもアポトーシス が正常に進行出来なくなる疾患として捉えられてい る.この過程には,アポトーシスの誘導に関与する c-myc,c-fos,c-jun などの癌原遺伝子,p 53 癌抑制遺 伝子,さらにアポトーシス抑制 bcl-2 遺伝子などが重 要な役割を果たしている.一方,生体内の酸素濃度, pH,ホルモン,蛋白などの生理的因子の他に,温熱, 紫外線,抗癌剤などの物理的刺激も細胞にアポトーシ スを誘導する.そして太田 はアポトーシスのシグナル 伝達機構の中心的役割をになっている細胞内小器官の ミトコンドリヤが...

The SBM mouse is a unique transgenic model of polycystic kidney disease (PKD) induced by the dysregulated expression of c-myc in renal tissue. In situ hybridization analysis demonstrated intense signal for the c-myc transgene overlying tubular cystic epithelium in SBM mice. Renal proliferation index in SBM kidneys was 10-fold increased over nontransgenic controls correlating with the presence o...

The C-erbB-2 proto-oncogene (also called HER-2 or neu) encodes a 185 Kda transmembrane glycoprotein [1]. It was mentioned that this protein is closely related, but yet different to EGF-receptor encoded by the C-erbB-2 proto-oncogene [6]. The structural alteration responsible for activation of C-erbB-2 gene is thought to result from a single mutation by a single amino acid substitution in the tr...

The human lbc oncogene product is a guanine nucleotide exchange factor that specifically activates the Rho small GTP binding protein, thus resulting in biologically active, GTP-bound Rho, which in turn mediates actin cytoskeletal reorganization, gene transcription, and entry into the mitotic S phase. In order to elucidate the mechanism of onco-Lbc transformation, here we report that while proto...

The proto-oncogene Bcl-2 is expressed in membranes of mitochondria and endoplasmic reticulum and mediates resistance against a broad range of apoptotic stimuli. Although several mechanisms of Bcl-2 action have been proposed, its role in different cellular organelles remains elusive. Here, we analyzed the function of Bcl-2 targeted specifically to certain subcellular compartments in Jurkat cells...