Comparative Tissue-Specific Toxicities of 20 Cancer Preventive Agents Using Cultured Cells From 8 Different Normal Human Epithelia

2001 ◽  
Vol 14 (3) ◽  
pp. 191-207 ◽  
Author(s):  
Eugene Elmore ◽  
Thanh-Thuy Luc ◽  
Vernon E. Steele ◽  
J. Leslie Redpath
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Robin-Lee Troskie ◽  
Yohaann Jafrani ◽  
Tim R. Mercer ◽  
Adam D. Ewing ◽  
Geoffrey J. Faulkner ◽  
...  

AbstractPseudogenes are gene copies presumed to mainly be functionless relics of evolution due to acquired deleterious mutations or transcriptional silencing. Using deep full-length PacBio cDNA sequencing of normal human tissues and cancer cell lines, we identify here hundreds of novel transcribed pseudogenes expressed in tissue-specific patterns. Some pseudogene transcripts have intact open reading frames and are translated in cultured cells, representing unannotated protein-coding genes. To assess the biological impact of noncoding pseudogenes, we CRISPR-Cas9 delete the nucleus-enriched pseudogene PDCL3P4 and observe hundreds of perturbed genes. This study highlights pseudogenes as a complex and dynamic component of the human transcriptional landscape.


1988 ◽  
Vol 66 (6) ◽  
pp. 636-649 ◽  
Author(s):  
Ronald W. Lennox ◽  
Leonard H. Cohen

At least two mechanisms generate tissue differences in the histone subtype composition during development: subtype dilution and subtype replacement. Subtype dilution, which occurs when cells continue dividing after having ceased to synthesize one or more histone subtypes, allows the elimination of stable subtypes. It is the major mechanism generating cell differences in histone composition in sea urchin embryogenesis. Subtype replacement has been observed in mammalian tissues, both in the intact animal and in cultured cells. It is most evident in nondividing cells but occurs to some extent in dividing cells as well. Examples of the two mechanisms are presented and their possible biological significance, as well as that of the differences they produce, is discussed.


PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e91805 ◽  
Author(s):  
Ayelet Avraham ◽  
Sean Soonweng Cho ◽  
Ronit Uhlmann ◽  
Mia Leonov Polak ◽  
Judith Sandbank ◽  
...  

2018 ◽  
Author(s):  
Laura Manuelidis

ABSTRACTSmall circular DNAs of 1.8 and 2.4kb were initially discovered in highly infectious CJD and scrapie particles from mammalian brain and cultured cells. Surprisingly, these protected cytoplasmic "SPHINX" DNAs contained replication (REP) initiation sequences resembling those of Acinetobacter phage viruses. An antibody was generated against a REP peptide encoded by the SPHINX 1.8 ORF that was not present in mammals. It bound to a 41kd "spx1" protein on Western blots. Cytologically, spx1 concentrated in spinal cord synapses and pancreatic islet, but not exocrine cells. We hypothesized that circular SPHINX DNAs are ancient symbiotic elements that can participate in functional differentiation and neurodegeneration. Cell and tissue specific patterns of spx1 expression shown below implicate somatic cell-to-cell communication and differentiation functions that would favor conservation of SPHINX 1.8 in evolution. Remarkably, primary human oocytes and spermatogonia, but not mature sperm, displayed intense cytoplasmic spx1 signals that underscore the maternal inheritance of SPHINX 1.8. These findings should encourage investigations of unexplored networks of incorporated environmental infectious agents that can be key actors in progressive neurodegeneration, immunity and cancer.


2015 ◽  
Vol 36 (4) ◽  
pp. 357-384 ◽  
Author(s):  
Päivi Pihlajamaa ◽  
Biswajyoti Sahu ◽  
Olli A. Jänne

AbstractThe physiological androgens testosterone and 5α-dihydrotestosterone regulate the development and maintenance of primary and secondary male sexual characteristics through binding to the androgen receptor (AR), a ligand-dependent transcription factor. In addition, a number of nonreproductive tissues of both genders are subject to androgen regulation. AR is also a central target in the treatment of prostate cancer. A large number of studies over the last decade have characterized many regulatory aspects of the AR pathway, such as androgen-dependent transcription programs, AR cistromes, and coregulatory proteins, mostly in cultured cells of prostate cancer origin. Moreover, recent work has revealed the presence of pioneer/licensing factors and chromatin modifications that are important to guide receptor recruitment onto appropriate chromatin loci in cell lines and in tissues under physiological conditions. Despite these advances, current knowledge related to the mechanisms responsible for receptor- and tissue-specific actions of androgens is still relatively limited. Here, we review topics that pertain to these specificity issues at different levels, both in cultured cells and tissues in vivo, with a particular emphasis on the nature of the steroid, the response element sequence, the AR cistromes, pioneer/licensing factors, and coregulatory proteins. We conclude that liganded AR and its DNA-response elements are required but are not sufficient for establishment of tissue-specific transcription programs in vivo, and that AR-selective actions over other steroid receptors rely on relaxed rather than increased stringency of cis-elements on chromatin.


Epigenetics ◽  
2010 ◽  
Vol 5 (6) ◽  
pp. 527-538 ◽  
Author(s):  
Srimoyee Ghosh ◽  
Allan J. Yates ◽  
Michael C. Frühwald ◽  
Jeffrey C. Miecznikowski ◽  
Christoph Plass ◽  
...  

2006 ◽  
Vol 291 (1) ◽  
pp. F9-F21 ◽  
Author(s):  
Tung-Tien Sun

The differentiation of cultured stratified epithelial cells can deviate significantly from that of normal epithelium, leading to suggestions that cultured cells undergo abnormal differentiation, or a truncated differentiation. Thus cultured epidermal and corneal epithelial cells stop synthesizing their tissue-specific keratin pair K1/K10 and K3/K12, respectively. The replacement of these keratins in the suprabasal compartment by K6/K16 keratins that are made by all stratified squamous epithelia during hyperplasia rules out a truncated differentiation. Importantly, the keratin pattern of in vivo corneal epithelium undergoing wound repair mimics that of cultured rabbit corneal epithelial cells. Although cultured urothelial cells continue to synthesize uroplakins, which normally form two-dimensional crystalline urothelial plaques covering almost the entire apical urothelial surface, these proteins do not assemble into crystals in cultured cells. Cultured epithelial cells can, however, rapidly regain normal differentiation on the removal of mitogenic stimuli, the use of a suitable extracellular matrix, or the transplantation of the cells to an in vivo, nonmitogenic environment. These data suggest that cultured epithelial cells adopt altered differentiation patterns mimicking in vivo regenerating or hyperplastic epithelia. Blocking the synthesis of tissue-specific differentiation products, such as the K1 and K10 keratins designed to form extensive disulfide cross-links in cornified cells, or the assembly of uroplakin plaques allows epithelial cells to better migrate and proliferate, activities that are of overriding importance during wound repair. Cultured urothelial and other stratified epithelial cells provide excellent models for studying the regulation of the synthesis and assembly of differentiation products, a key cellular process during epithelial wound repair.


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