Air pollution may shorten telomers in babies

A study conducted before and after the 2004 closure of a coal-burning power plant in Tongliang, China, found children born before the closure had shorter telomeres than those conceived and born after the plant stopped polluting the air. Telomeres are specialized sections of DNA that allow chromosomes to be faithfully copied during cell division. However, with each round of cell division, telomeres shorten, resulting in a gradual loss of genomic stability. Shortened telomere length has been linked with cancer and heart disease, cognitive decline, aging, and premature death.

Led by Deliang Tang and Frederica Perera at Columbia University's Mailman School of Public Health, the research team analyzed telomere length in the umbilical cord blood of 255 newborns, about half of whom were born before the plant closure and half conceived and born after. In babies born pre-closure, researchers found higher levels of PAH-DNA cord adducts, a biomarker for exposure to polycyclic aromatic hydrocarbons , a toxic component of air pollution from coal plants.

 Elevated levels of these adducts in cord blood were associated with shorter telomeres-the first time this relationship has been tested as well as with lower levels of brain-derived neurotropic factor (BDNF), a protein involved in neuronal grown. However, telomere length was not associated with developmental score in the subset of 210 children tested at age 2, although the researchers say the finding doesn't rule out telomere length-related neurodevelopmental problems at later ages.

Individual's telomere length at birth is known to influence their risk for disease later during adulthood, high levels of air pollution in Tongliang prompted the government to shut down the local coal-burning power plant to improve community health. This action, announced in advance, provided a unique opportunity to compare data on ambient PAH levels, biomarkers, and health outcomes in two successive cohorts of children, with and without prenatal exposure to emissions from the coal-fired power plant.

In previously published research on these cohorts, the authors reported newborns born after the plant closure had lower levels of PAH-DNA adducts, lower rates of various health outcomes, and increased levels of BDNF. The new study adds to the evidence that closing this coal-burning power plant was beneficial to the health and future well-being of newborns there, reducing exposure to air pollution is recommended for pregnant women and infants.
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Epigenetic reveals early breast cancer development

Changing the epigenetic code of a single gene is enough to cause a healthy breast cell to begin a chain reaction and become abnormal, Epigenetic changes are a hallmark of cancer, but up until now, it has not been known whether these changes on their own are sufficient to push healthy cells down the cancer path.

 Using a CRISPR-dCas9 epigenetic editing tool, the researchers methylated different genes in healthy breast cells and found that those changes were sufficient to cause the cells to undergo hyperproliferation - abnormally rapid cell division which is an early stage of tumour initiation.

The epigenetic changes are inherited as long as the cell divides, and that the team's manipulations permanently and negatively affected the biology of a normal breast cell from a healthy individual. Epigenetic editing could also be used to design novel therapies by initiating permanent changes to cell biology.

This may be a more viable or alternative way forward for gene editing as any potential mistakes would be less damaging than directly editing the DNA sequence, and epigenetic editing would be more easily reversible if needed. Epigenetic fluctuations happen all the time in human cells. During ageing, human epigenome is progressively distorted.
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Stress hormone reduced the effectiveness of cancer treatment

Stress reduction therapy is very important for cancer patients, stress hormones during treatment can prevent the cancerous cells in the body from dividing and reacting.

These hormones prevent the growing tumors from being treated by the cancer drugs that are used for the patients. Stress reduction therapy is essential during cancer treatment to promote the success of the drugs and cancer treatment.

Chemotherapy method of cancer treatment targets rapidly dividing cells, cells exposed to stress hormones such as cortisol and norepinephrine generate destructive DNA damaging free radicals molecules.

This causes the cells temporarily to stop their relentless cell division as DNA repair mechanisms starts and protects the tumors from the lethal effects of chemotherapy.

Stressed mice with breast cancer produced higher levels of a nitric oxide-generating enzyme iNOS in their tumors. Greater iNOS activity leads to more aggressive breast cancer.
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Three-dimensional organization of DNA

The three-dimensional organization of DNA in the nucleus influences our biology, from how our genome organized our cellular activity to how genes are passed from parents to children.

 X-rays and microscopy showed that the primary level of chromatin organization involves 147 bases of DNA spooling around proteins to form particles approximately 11 nanometers (nm) in diameter called nucleosomes.

These nucleosome "beads on a string" are then thought to fold into discrete fibers of increasing diameter (30, 120, 320 nm etc.), until they form chromosomes.

Researchers used ChromEMT to image and measure chromatin in resting human cells and during cell division (mitosis) when DNA is compacted into its most dense form -the 23 pairs of mitotic chromosomes that are the iconic image of the human genome.

Chromatin that has been extracted from the nucleus and subjected to processing in vitro - in test tubes - may not look like chromatin in an intact cell, so it is tremendously important to be able to see it in vivo.

Chromatin's packing density, and not some higher-order structure, that determines which areas of the genome are active and which are suppressed.

Controlling access to chromatin could be a useful approach to preventing, diagnosing and treating diseases like cancer.

Chromatin does not need to form discrete higher-order structures to fit in the nucleus, It's the packing density that could change and limit the accessibility of chromatin, providing a local and global structural basis through which different combinations of DNA sequences, nucleosome variations and modifications could be integrated in the nucleus to exquisitely fine-tune the functional activity and accessibility of our genomes.
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How biological clock affects male fertility

Waiting until forties before trying to become fathers could reduce male fertility because sperm DNA becomes damaged with age.

Frequent cell division to make new generation of sperm daily increases errors in cell formation as men get older and the risk increases everyday. Genetic errors may get into sperm as men aged.

The cumulative effect of these errors as cell division goes on and on and on affects children produced by older men. Autism, epilepsy and schizophrenia are associated with older sperm.

Older men may not be able to impregnate a woman naturally, it may take a long period of time to archive conception and risk of miscarriage is very high.

Healthy lifestyle can prevent DNA damage and changes to genes. Men must eat healthily diet, avoid smoking, engage in regular physical activities and avoid hot baths, as sperm likes cool temperatures to be in good reproductive shape.
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Scientists have discovered proteins that suppress breast cancer tumours

Scientists have discovered a protein that can suppress the growth of breast cancer tumours.

 Proline-Rich Homeodomain protein (PRH) is a protein that controls and regulates genes.

 PRH is known to be important in multiple cell types, this work has important implications for other types of cancer.

When PRH protein levels are reduced in a breast tumour, the cells are more able to divide, speeding up the progression of the tumour.

Some of the genes which are regulated by PRH can specifically contribute to the increased cell division.

The researchers also carried out tests in a tumour model of mammary cancers, increasing PRH levels to observe the effect.

They discovered that high levels of PRH blocked the formation of the tumours, this shows that  PRH can block tumour formation in some breast cancers.

     
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