Cell Biology: Chromatin Structure and Gene Expression

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What is the characteristic feature of euchromatin?

Specific histone modifications like H3K4 di- or trimethylation (correct)

Linked with gene silencing

Marked by H3K9 trimethylation and H4K20 trimethylation

Condensed structure

What is the typical feature of heterochromatin?

Marked by H3K9 trimethylation and H4K20 trimethylation (correct)

Linked with active gene expression

Marked by H3K4 di- or trimethylation

Less condensed structure

What happens to the overall structural organization of nuclear DNA during aging and cancer development?

It becomes compromised (correct)

It is completely lost

It becomes more organized

It remains unchanged

What is a potential outcome for aged cells with altered epigenome?

They can acquire either tumor suppressive or oncogenic programs Signup and view all the answers

What happens to the subpopulation of aged cells with cancer driving mutations and epigenetic alterations?

They undergo clonal expansion Signup and view all the answers

What distinguishes oncogenic transformations from normal, nontumorigenic age-associated changes?

The different genomic regions involved Signup and view all the answers

What is a common characteristic of epigenetic changes during aging?

They follow a program resulting in a specific transcriptome Signup and view all the answers

What is the primary function of senescence-associated heterochromatic foci (SAHF) during senescence?

To establish a heterochromatic region with specific markers Signup and view all the answers

What is a consequence of continuous cell division cycles in aging cells?

Constant DNA damage and oxidative stress Signup and view all the answers

What is a common feature of chromatin alterations in cancer cells?

Formation of transcriptional hubs and super enhancer domains Signup and view all the answers

What is the primary goal of understanding common molecular mechanisms driving epigenetic alterations in cancer and noncancerous aged cells?

To develop better therapeutic strategies and markers for early cancer detection Signup and view all the answers

Which of the following genes are normally silenced in somatic cells but can be ectopically expressed in aging and cancer cells?

Extraembryonic antigens and cancer germline antigens Signup and view all the answers

What is the consequence of large-scale reorganizations in the genome?

Incidental gene expression changes Signup and view all the answers

What is the consequence of telomere deprotection in aging cells?

Constant stress and large-scale epigenetic changes Signup and view all the answers

What is the potential benefit of anti-aging strategies such as senolytics and senomorphics?

Targeting and mitigating multiple age-related processes Signup and view all the answers

What is the primary characteristic of transcriptional hubs in cancer cells?

They meet the demand for high expression of oncogenic genes Signup and view all the answers

What is the role of hTERT in aging cells?

Efficient DNA repair and reducing mitochondrial oxidative stress Signup and view all the answers

What is the relationship between continuous cell division cycles and age-related epigenetic changes?

Continuous cell division cycles enable age-related epigenetic changes Signup and view all the answers

What is a possible outcome of aberrant DNA methylation in gastric epithelial cells?

Inflammation and potentially gastric cancer Signup and view all the answers

What is the role of phosphoinositide 3-kinase in cancer?

Regulation of NOX-derived reactive oxygen species Signup and view all the answers

What is the effect of mitochondrial DNA haplotypes on gene expression?

Differential patterns of DNA methylation and gene expression Signup and view all the answers

What is the role of acetate in mitochondrial metabolism?

Coupling to mitochondrial metabolism Signup and view all the answers

What is the relationship between l-carnitine and mitochondria?

l-carnitine prevents metabolic inflexibility and disease initiation Signup and view all the answers

What is the role of telomeres in human disease?

Telomeres contribute to the development of human diseases Signup and view all the answers

What is a hallmark of the alternative lengthening of telomeres pathway?

Loss of ATRX and genome instability Signup and view all the answers

What is a key feature of telomerase, as described in the literature?

Its nontelomeric activities Signup and view all the answers

What is the focus of a recent scientific study, as described in the literature?

The role of senolytics in cancer therapy Signup and view all the answers

What is the relationship between telomerase expression and epigenetic ageing?

Telomerase expression has no effect on epigenetic ageing Signup and view all the answers

What is the goal of science-driven nutritional interventions, as described in the literature?

To prevent and treat cancer Signup and view all the answers

What is the role of DNA, RNA, and histone methylation in ageing and cancer, as described in the literature?

They play a role in ageing and cancer Signup and view all the answers