NUTRITIONAL PROTECTION OF

DNA & TELOMERES

Michael FenechCSIRO Food and Nutritional SciencesGENOME HEALTH NUTRIGENOMICS LABORATORY

michael.fenech@csiro.au

HDA August 2010

DNA DAMAGE BIOMARKERS FOR STUDYING NUTRITIONAL

PREVENTION OF DNA DAMAGE

LYMPHOCYTE CBMN ASSAY

RBC MN ASSAY

BUCCAL MN ASSAY

COMET ASSAY

TELOMERE LENGTH MITOCHONDRIAL DNA DELETION DNA OXIDATION DNA METHYLATION

Dietary Reference Values for DNA Damage PreventionFenech M (2010) Am. J. Clin. Nutr.

Genome damageMicronuclei

Human cellswith damaged& unstablegenomes

• Oxidative stress• Nutrient deficiency• Excess calories

• Strand breaks in DNA•Chromosome malsegregation•DNA hypomethylation•Telomere shortening

CYTOKINESIS-BLOCK MICRONUCLEUS (CBMN) ASSAY

18-2

5

26-3

5

36-4

5

46-5

5

56-6

5

66-7

5

76-9

0

0

10

20

30

40

50

MN

per

100

0 B

N c

ells

AGE (years)

Genome damage increases with age

Fenech et al. 2000 NEONATES

Chromosomeloss

Acentric Fragment &Mis-repair

Telomereend fusion

TELOMERE & CENTROMERE PROBES

TELOMERE & CENTROMERE PROBES

Lymphocytes exposed to X-rays(Fenech et al. Mutagenesis 1999, 2003)

Oral squamouscell carcinoma(Saunders et al PNAS 2000)

Ch 4 Ch 4

Ch 11

Ch 4 Ch 4

NUCLEOPLASMIC BRIDGES ARE IMPORTANT BIOMARKERS OF DNA BREAK MIS-REPAIR, TELOMERE DYSFUNCTION & CHROMOSOMAL INSTABILITY

MICRONUCLEATED CELLS

12 24 60 1200

10

20

30

40

*

**

[A]

folic acid in medium (nM)

MN

ed B

Ns/

1000

BN

s ANOVA P < 0.0001

NUCLEAR BUDS

12 24 60 1200

5

10

15

ANOVA P<0.0001

*

**

[B]

folic acid in medium (nM)

Bud

s/10

00 B

Ns

NUCLEOPLASMIC BRIDGES

12 24 60 1200.0

2.5

5.0

7.5

10.0ANOVA P<0.0001*

**

[C]

[folic acid] in medium (nM)

NP

B/1

000

BN

s

URACIL

12 24 60 1200

10

20

30

40

50ANOVA P < 0.0001

[folic acid] in medium (nM)

pg u

raci

l /µ

g D

NA

* *

[D]

Crott et al. Carcinogenesis 2001

FOLATE DEFICIENCY CAUSES CHROMOSOMAL INSTABILITY

MICRONUTRIENTS AND GENOME DAMAGERESULTS OF ANALYSIS OF FOOD FREQUENCY QUESTIONNAIRE AND GENOME DAMAGE DATABASE

Fenech et al.Carcinogenesis(2005)

% variation in genome damage withincreased intake relative to lowest tertile of intake

Vita

min

E

Cal

cium

Fola

te

Ret

inol

Nic

otin

ic a

cid

-Car

oten

eβ R

ibof

lavi

n

Pant

othe

nic

acid

Bio

tin

-50-40-30-20-10

010203040506070

mid-tertilehighest tertile

*

** * *

*

*

*

**

** P < 0.006

% v

aria

tion

in M

N fr

eq

ALMONDS

WHEATBRAN

CHEDDAR CHEESE

BROCCOLI (BOILED)

TUNA (CANNED)

BEEF (COOKED)

BANANA0

100

200

300CALCIUMFOLATENIACINVITAMIN EBETA-CAROTENERETINOL

AMOUNTS IN 100g EXPRESSED AS % OF MIMIMUMREQUIREMENT FOR OPTIMUM GENOME HEALTH

Fenech, Food Chem Tox 2008

Q. Which dietary pattern will best protect the genome?

A. It depends on the “nutriome” of the foods you prefer to eat

Would a“FBNERC” POLYPILL

do the trick??

TELOMERES (TTAGGG repeats) ARE ESSENTIALFOR CHROMOSOMESTABILITY

TELOMERE SHORTENING OR DYSFUNCTION INCREASES RISK FOR CANCER ANDACCELERATED SENESCENCE

TELOMERES

Wong & Collins Lancet 2003

Shorter telomeres in WBCs and Buccal cells of Alzheimer’s disease (AD) cases compared to controls

Young contro

ls

Old contro

ls

Younger AD

Older AD

0

25

50

75

100

125

150

175 a

b

bcc

Abs

olut

e te

lom

ere

leng

th(K

b pe

r di

ploi

d ge

nom

e)

Young contro

ls

Old contro

ls

Younger AD

Older AD

0

10

20

30

40

50 aa

ab

b

Abs

olut

e te

lom

ere

leng

th(K

b pe

r di

ploi

d ge

nom

e)

young controls (N=30), old controls (N=26), younger AD (N=14), older AD (N=18).

Thomas et al, Mech Aging Dev, 2008

WBC TL <115 Kb per diploid genome OR of being diagnosed with AD is 10.8specificity 46% sensitivity 92.9%.

Buccal TL <40 kb per diploid genomeOR of being identified with AD is 4.6 specificity 63% sensitivity 72.7%.

High protein (TWD) or high carbohydrate (HC) weight-loss diets reverse telomere shortening in rectum in over-weight men

TWD HC

Telo

mer

e le

ngth

(kb)

0 12 52 0 12 52

2.6

5.2

7.8

10.4

13.0

15.6

18.2

0.0

2 way ANOVAP<0.0001

weeks on dietO’Callaghan, Clifton, Noakes, Fenech. Rejuvenation Res. 2009

O’Callaghan, Clifton, Noakes, Fenech. Rejuvenation Res. 2009

REDUCTION IN FAT CORRELATES WITH INCREASE IN TELOMERE LENGTH

Telomere length in older men is significantly associated with plasma folate and homocysteine

Males; r = -0.57, p = 0.004 (n = 24). Females; r = 0.092, p = 0.68 (n = 23)

Males; r = 0.42, p = 0.04 (n = 24). Females; r = -0.11, p = 0.61 (n = 23)

Telomere length is negatively correlated with plasma homocysteine in older men.

Telomere length is positively correlated with plasma folatein males but not in females.

Bull, O’Callaghan, Mayrhofer & Fenech Rejuvenation Res (2009)

FOLATE DEFICIENCY

NIACIN ORNICOTINIC

ACIDDEFICIENCY

ANTIOXIDANTDEFICIENCY

OR OXIDATIVESTRESS

8-OHdG

URACIL

HYPO-METHYLATED

SUBTELOMERE

BREAKS IN TELOMERE

REDUCEDTRF1, TRF2

BINDING

LOSS OFTELOMERE

LENGTH CONTROL

DYSFUNCTIONALAND/OR SHORT

TELOMERES;TELOMERE END

FUSIONS;AND CIN

REDUCED TANK1

ACTIVITY

?

?

?

MALNUTRITION & TELOMERE DAMAGE CASCADE

Bull & Fenech Proc. Br Nutr Soc 2008

FOLATE

VITAMIN E

VITAMIN D

Ω3-FATTY ACIDS

CEREAL FIBRE

MULTIVITAMIN USE

PUFA

OXIDATIVE STRESS

OBESITY

PSYCHOLOGICAL STRESS

PROCESSED MEAT

HOMOCYSTEINE

LONGER SHORTERTELOMERES

CURRENTKNOWLEDGE

CSIROC. SalisburyP. Thomas

J. CrottV. Dhillon

M. HorT. AlmondJing WuC. Bull

N. O’CallaghanW. LeifertG. Patten

B. BenassiS. Beetstra

Acknowledgements

FUNDING•Kellogs Pty Ltd,•MLA•Blackmore’s,•Nutrilite/Amway•NHMRC,•CancerCouncil SA, •NIH•EUCancerRiskBio-markers Program•DPI-Victoria

NATHANO’CALLAGHAN

CAROLINEBULL

PHILTHOMAS

THE GENOME HEALTH NUTRIGENOMICS DREAM TEAM