Reassessment of immortalization complementation group D.

E L Moy; E L Duncan; B Hukku; R R Reddel

doi:10.1016/s0531-5565(97)00092-2

Home/Archive/PubMed

PubMed · 9785092

Reassessment of immortalization complementation group D.

E L Moy·E L Duncan·B Hukku·R R Reddel

View original source ↗Export metadata ↓

Abstract

Previous somatic cell hybridization studies have assigned many human cell lines to one of four complementation groups (A-D) for immortalization. We report here that the A1698DM cell line, which contains selectable markers and has previously been defined as the immortalization group D representative, was derived from T24 cells rather than A1698. A1698DM did not undergo senescence when fused with cell lines assigned to groups A, B, or C. This raises the possibility that this cell line has undergone further evolution and lost multiple putative senescence genes so that it is now unable to complement any, or most, other cell lines for senescence. Cell lines previously assigned to group D may, therefore, be heterogeneous with respect to the genetic changes that resulted in their immortalization. This has important implications for strategies to clone senescence genes based on complementation groups.

Explore related subjects

Cell Fusion Cell Line, Transformed Cellular Senescence Chromosome Mapping DNA Fingerprinting Genetic Complementation Test Genetic Markers Humans Hybrid Cells Karyotyping Tumor Cells, Cultured Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

E L Moy, E L Duncan, B Hukku, R R Reddel. Reassessment of immortalization complementation group D.. https://doi.org/10.1016/s0531-5565(97)00092-2

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2015

Sex is a ubiquitous, ancient, and inherent attribute of eukaryotic life.

Sexual reproduction and clonality in eukaryotes are mostly seen as exclusive, the latter being rather exceptional. This view might be biased by focusing almost exclusively on metazoans. We analyze and discuss reproduction in the context of extant eukaryotic diversity, paying special attention to protists. We present results of phylogenetically extended searches for homologs of two proteins functioning in cell and nuclear fusion, respectively (HAP2 and GEX1), providing indirect evidence for these processes in several eukaryotic lineages where sex has not been observed yet. We argue that (i) the debate on the relative significance of sex and clonality in eukaryotes is confounded by not appropriately distinguishing multicellular and unicellular organisms; (ii) eukaryotic sex is extremely widespread and already present in the last eukaryotic common ancestor; and (iii) the general mode of existence of eukaryotes is best described by clonally propagating cell lines with episodic sex triggered by external or internal clues. However, important questions concern the relative longevity of true clonal species (i.e., species not able to return to sexual procreation anymore). Long-lived clonal species seem strikingly rare. We analyze their properties in the light of meiotic sex development from existing prokaryotic repair mechanisms. Based on these considerations, we speculate that eukaryotic sex likely developed as a cellular survival strategy, possibly in the context of internal reactive oxygen species stress generated by a (proto) mitochondrion. Thus, in the context of the symbiogenic model of eukaryotic origin, sex might directly result from the very evolutionary mode by which eukaryotic cells arose.

Cell Fusion↗

PubMed2006

Proteomic analysis of hypoxia-induced responses in the syncytialization of human placental cell line BeWo.

Syncytiotrophoblast formation is affected by a number of pathological conditions and suppressed syncytiotrophoblast formation due to hypoxia may play a role in the pathogenesis of preeclampsia. However, the molecular basis of hypoxia-inhibited trophoblast syncytialization is poorly understood. To determine the effect of hypoxia on trophoblast syncytialization, a proteomic analysis was performed in the human cytotrophoblast cell line BeWo using two-dimensional electrophoresis and MALDI-TOF-TOF-MS. Hypoxia induced marked inhibition of BeWo cell fusion and differentiation. The proteomic profiling was established under hypoxia in BeWo cell syncytialization. The results showed that twenty proteins were significantly up-or down-regulated under hypoxia, compared with cells under normoxia. In response to hypoxia, three antioxidants, peroxiredoxin 1, peroxiredoxin 2 and 1-Cys peroxiredoxin, were down-regulated, two proteins involved in glycolysis pathway (malate dehydrogenase and enolase) were up-regulated. The expression of two members of the annexin family (annexin A2 and annexin A5) increased. We also found a decreased expression of 14-3-3 tau protein in hypoxia treated cells. Proteins implied in protein degradation and folding were also identified. The expression of two cytoskeleton components (keratin 1 and beta-actin) was found to be down-regulated. In addition, galectin-3 was up-regulated. These proteins have been implicated in regulating cellular oxidative stress, glycolysis, signal transduction, protein folding and degradation, cell mobility and cytoskeletal structure formation. Western blot analysis revealed that the levels of peroxiredoxin 1 and 14-3-3 tau decreased, whereas the levels of annexin A5 and annexin A2 increased in BeWo cells under hypoxia. These findings provided new insights into the molecular mechanisms in mediating cellular response to hypoxia in trophoblast syncytialization.

Cell Fusion↗

PubMed2006

Complexities in human herpesvirus-6A and -6B binding to host cells.

Human herpesvirus-6A and -6B uses the cellular receptor CD46 for fusion and infection of the host cell. The viral glycoprotein complex gH-gL from HHV-6A binds to the short consensus repeat 2 and 3 in CD46. Although all the major isoforms of CD46 bind the virus, certain isoforms may have higher affinity than others for the virus. Within recent years, elucidation of the viral complex has identified additional HHV-6A and -6B specific glycoproteins. Thus, gH-gL associates with a gQ1-gQ2 dimer to form a heterotetrameric complex. In addition, a novel complex consisting of gH-gL-gO has been described that does not bind CD46. Accumulating evidence suggests that an additional HHV-6A and -6B receptor exists. The previous simple picture of HHV-6A/B-host cell contact therefore includes more layers of complexities on both the viral and the host cell side of the interaction.

Cell Fusion↗