Premalignant lesions and cellular senescence

2022 ◽  
pp. 29-60
Author(s):  
Eleni Georgakopoulou ◽  
Konstantinos Evangelou ◽  
Vassilis G. Gorgoulis
2010 ◽  
Vol 10 ◽  
pp. 727-741 ◽  
Author(s):  
Raya Saab

Cellular senescence is a tumor-suppressor mechanism that has been shown to occur in response to multiple signals, including oncogenic stress, DNA damage, oxidative stress, telomere shortening, and other tumor-promoting insults. Over the past decade, much has been uncovered regarding the phenotype of this tumor-suppressor response and the underlying pathways necessary for its establishment. However, we have also learned that the intricate details of signaling pathways underlying senescence as a tumor-suppressor response are very much context dependent. In addition, cross-talk among pathways, and negative and positive feedback loops, all complicate our understanding of this process. This short review attempts to summarize what is known to date regarding senescence in tumor suppression, bothin vitroandin vivo. Further insights into pathways necessary for senescence will hopefully identify appropriate targets for interventions to not only induce senescence as a treatment of cancerous lesions, but also to maintain this state in premalignant lesions in an effort to prevent progression to cancer.


2020 ◽  
Vol 477 (14) ◽  
pp. 2715-2720
Author(s):  
Susana Castro-Obregón

The nuclear envelope is composed by an outer nuclear membrane and an inner nuclear membrane, which is underlain by the nuclear lamina that provides the nucleus with mechanical strength for maintaining structure and regulates chromatin organization for modulating gene expression and silencing. A layer of heterochromatin is beneath the nuclear lamina, attached by inner nuclear membrane integral proteins such as Lamin B receptor (LBR). LBR is a chimeric protein, having also a sterol reductase activity with which it contributes to cholesterol synthesis. Lukasova et al. showed that when DNA is damaged by ɣ-radiation in cancer cells, LBR is lost causing chromatin structure changes and promoting cellular senescence. Cellular senescence is characterized by terminal cell cycle arrest and the expression and secretion of various growth factors, cytokines, metalloproteinases, etc., collectively known as senescence-associated secretory phenotype (SASP) that cause chronic inflammation and tumor progression when they persist in the tissue. Therefore, it is fundamental to understand the molecular basis for senescence establishment, maintenance and the regulation of SASP. The work of Lukasova et al. contributed to our understanding of cellular senescence establishment and provided the basis that lead to the further discovery that chromatin changes caused by LBR reduction induce an up-regulated expression of SASP factors. LBR dysfunction has relevance in several diseases and possibly in physiological aging. The potential bifunctional role of LBR on cellular senescence establishment, namely its role in chromatin structure together with its enzymatic activity contributing to cholesterol synthesis, provide a new target to develop potential anti-aging therapies.


2001 ◽  
Vol 120 (5) ◽  
pp. A87-A87
Author(s):  
J FOX ◽  
B SHEPPARD ◽  
C DANGLER ◽  
M WHARY ◽  
M IHRIG ◽  
...  

2015 ◽  
Vol 24 (2) ◽  
pp. 235-239 ◽  
Author(s):  
Jan Ulrych ◽  
Vladimir Fryba ◽  
Helena Skalova ◽  
Zdenek Krska ◽  
Tomas Krechler ◽  
...  

Heterotopic pancreas is a congenital pathology of the gastrointestinal tract, particularly rare in the esophagus. Both symptomatology and findings during preoperative examinations are non-specific and therefore do not often lead to an accurate diagnosis, which is usually revealed only by histopathological assessment of a resected specimen. We report an unusual case of a patient suffering from severe dysphagia caused by heterotopic pancreas in the distal esophagus with chronic inflammation and foci of premalignant changes. This article also reviews 14 adult cases of heterotopic pancreas in the esophagus previously reported in the literature, with the aim of determining the clinical features of this disease and possible complications including rare premalignant lesions and malignant transformation. Especially with regard to those complications, we suggest that both symptomatic and incidentally found asymptomatic lesions should be resected.


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