Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Amplification of the c-myc gene has been frequently reported in breast carcinomas. However the precise function of the c-myc protein is still unknown and the nature of the selective advantage offered to a cell by an overexpression of such a protein is unclear. We are addressing this question using the SW 613-S human breast carcinoma cell line as a model system. This cell line harbours an amplified c-myc gene and a mutated c-Ki-ras gene. By various criteria the amplified c-myc gene of SW613-S cells appears undistinguishable from a normal human c-myc gene. The SW613-S cell line is heterogeneous: it contains cells with a high level of amplification and carrying the extra copies of the c-myc gene in double minute chromosomes (DMs) and cells with few c-myc genes integrated into chromosomes. DM-containing cells are progressively lost upon in vitro cultivation but are selected for during in vivo growth, as tumors in nude mice, or by cultivating the cells in a chemically defined, serum-free medium or under conditions preventing anchorage. Clones with different levels of amplification and different chromosomal localization of the c-myc copies were isolated from the SW 613-S cell population. Those with a high level of amplification and expression of the c-myc gene are tumorigenic in nude mice, whereas those with a low level are not. Introduction of c-myc gene copies by transfection confers tumorigenicity to the nontumorigenic clones, indicating that a high level of amplification of the c-myc gene contributes to the tumorigenic phenotype of SW 613-S cells. Tumorigenic clones grow unattached, are able to proliferate in a chemically defined medium, and produce high levels of several growth factors (e.g. TGF-alpha, IGF2). Nontumorigenic clones are more dependent upon anchorage for growth, show a restricted growth in defined medium, and produce low or undetectable level of the growth factors tested. We have identified several genes, besides c-myc, the expression level of which is markedly different in the two types of clones. TGF-alpha, IGF2, PDGF-A, int-2, cytokeratins K8 and K18 and ferritin H chain are overexpressed in tumorigenic clones. In contrast, c-erbB1 (EGF receptor), c-jun, vimentin and p53 are expressed at a higher level in the nontumorigenic clones. Finally the major histocompatibility class I antigens, ferritin L chain, TGF-beta and c-Ki-ras, are examples of genes expressed at the same level in both types of clones.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The human breast carcinoma cell line SW 613-S: an experimental system to study tumor heterogeneity in relation to c-myc amplification, growth factor production and other markers (review). 268 29

The mRNA levels of 39 target genes were monitored in unfertilized eggs of 14 rainbow trout sampled the day of ovulation and again 5, 14, and 21 days later. For all 56 collected egg batches, an egg sample was fertilized to estimate egg quality by monitoring embryonic development. Remaining eggs were used for RNA extraction and subsequent real-time PCR analysis. A significant drop of egg quality was observed when eggs were held in the body cavity for 14 or 21 days post-ovulation (dpo). During the same period, eight transcripts (nucleoplasmin or Npm2, ferritin H, tubulin beta, JNK1, cyclin A1, cyclin A2, cathepsin Z, and IGF2) exhibited a differential abundance at one or several collection time(s). Interestingly, we observed higher levels of cyclins A1 and A2 mRNAs in eggs taken 5 days post-ovulation than in eggs taken, from the same females, at the time of ovulation. In addition, seven transcripts exhibited a differential abundance between low quality and high quality eggs. Low quality eggs were characterized by lower levels of Npm2, tubulin beta, and IGF1 transcripts. In contrast, keratins 8 and 18, cathepsin Z, and prostaglandin synthase 2 were more abundant in low quality eggs than in high quality eggs. In this study, we have demonstrated differences in mRNA levels in the rainbow trout egg that are reflective of developmental competence differences induced by post-ovulatory ageing. The putative role of these transcripts in post-ovulatory ageing-induced egg quality defects is discussed with special attention for corresponding cellular functions.
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PMID:Large scale real-time PCR analysis of mRNA abundance in rainbow trout eggs in relationship with egg quality and post-ovulatory ageing. 1607 64