DNA:Damage and response

DNA DAMAGE AND RESPONSE

:

Carlos A. Osorio Gutiérrez

UPB

Faculty of Medicine

Medellín, 2015

INTRODUCTION

Genome damages are very common, that is why cells have developed detecting and reparation mechanisms that let them conserve the original code so their offspring could keep the necessary structural and functional characteristics for its survival.

CT scan: DNA damage

‘Using new laboratory technology, scientists have shown that cellular damage is detectable in patients after CT scanning, according to a new study led by researchers at the Stanford University School of Medicine.’

CT scan: DNA damage

Stanford University School of Medicine.

67 patients undergoing cardiac CT angiograms.

Whole-genome sequencing + flow cytometery

Blood→ before and after undergoing the procedure

RESULTS:

↑DNA damage and cell death

↑expression of genes involved in cell repair and death

↑%cells damaged by scan (CD)→repaired

↓%CD→died

CT scan: DNA damage

CT scan: DNA damage

It was not detected any DNA damage in patients who: Received the lowest doses

of radiation

Were of average weight

Had regular heart rates

STUDENT´S OPINION:

I consider this discovery relevant because it shows the adversal effects of a necessary diagnostic method as CT scanning, and also promotes the biomolecular studies to find a possible buffer of the genome changes in affected cells.

CT scan: DNA damage

ATM: triggered alarm

‘How does our body keep its DNA intact? Researchers at Erasmus MC have just found a new piece of this puzzle. They discovered a novel alarm that cells use to signal DNA damage."We have now shown that this alarm is also set off during transcription (expression) of damaged genes.”’

ATM: triggered alarm

Cellular metabolic byproducts

Chemicals

Radiation

↓

DNA damage

↓

Alarm

Erasmus MC

ATM: triggered alarm

←Alarm→

Stops DNA duplication and cell division

UV-induced transcription halting

ATM protein

↓

↓

ATM: triggered alarm

Alternative splicing of gene transcripts

↓

New protein variants

↓

Counteracting negative effects of DNA lesions.

↓

↓

ATM protein

↓

ATM: triggered alarm

STUDENT´S OPINION:

• I find this discovery considerably relevant because it shows another target for biomolecular cancer studies : (In some cases) the protein it is not abscent but its alarm is failing.

MEDICAL UTILITY

MEDICAL UTILITY

The discovery of CT scanning cell repercussions, could be used as a reason for designing less-harmful diagnostic methods, with the same or even more effectiveness.

MEDICAL UTILITY

CT scanning damage mechanism could be used as a target of biomolecular investigation so if it was not possible changing the methods, it would be possible reducing the adverse effects (aging and tumor development).

MEDICAL UTILITY

The discovery of the activating mechanism of ATM protein shows a new path for CA treatment: based on the correction of previous processes of the ATM protein activation.

BIBLIOGRAPHY A novel DNA damage alarm (June 25,2015) .

ScienceDaily. Retrieved on August 07 of 2015 from: http://www.sciencedaily.com/releases/2015/06/150625081524.htm

DNA damage seen in patients undergoing CT scanning, study finds (July 22,2015). ScienceDaily. Retrieved on August 07 of 2015 from: http://www.sciencedaily.com/releases/2015/07/150722144634.htm

MARTINEZ SÁNCHEZ, Lina María. Biología molecular. 8. ed. Medellín: UPB. Fac. de Medicina, 2015. 109-115p.

‘Most people say that it is the intellect which makes a great scientist. They are wrong: it is character.’

Albert Einstein