1. Identification of ERα gene polymorphism in adolescent idiopathic scoliosis (AIS)
L.-O. Lévesque, A. Moreau, PhD S. Leclerc, PhD, H. Labelle, MD, G. Grimard, MD, F. Moldovan, PhD.

2. What is adolescent idiopathic scoliosis ?
80% of scoliosis are idiopathic (without cause)
Affects 2-3% of adolescents in Quebec
Only 0,2% have a cobb angle over 40°

3. Do estrogens contribute to AIS?
AIS affects mainly girls
AIS appears at the same time that estrogens rise in young girls blood.
Scoliosis progression can be predicted by bone age, menarche and pubertal stage, all of which are related to the presence of estrogens
Environmental factors: phytoestrogens (nutrition)

4. Known receptors of estrogens
There are 2 types of known receptors to the estrogens: ERα and ERβ
Both are nuclear receptors of the steroids receptors super-family
The ligand–receptor complex binds to ERE and AP-1 promoter sequence
New evidences for a non-nuclear rapid action of the Estrogens
The role of ERα and ERβ remains to be ascertained

5. Methodology
All these experiments were done on human tissues or cell lines of human origin.
MG-63, Control tissues and Scoliotic tissues all of which have been collected according to Sainte-Justine hospital’s ethic protocol
By RT-PCR, we have seek ERα and ERβ in different human cell lines and scoliotic cell lines
We have performed digestion by restriction enzymes on PCR amplicon to ascertain the presence of polymorphisms associated with ERα.

6. RFLPolymorphism Allele A Allele B Amplicons No enzymes PvuII XbaI
Digestion
enzyme
enzyme
Digested fragments

7. Results # of Scoliosis XbaI PvuII Type of Scoliosis Type of Curve sex
1er Cobb
Cobb pre-op
Patient 1 Xx Pp
AIS
Right thoracic F
n/a 60
Patient 2 XX PP M 30 38
Patient 3
Paralytic Scoliosis
Left thoracic 61
Patient 4 51 57
Patient 5 55 59
Patient 6 50
Patient 7 58

8. Expression of ERα and ERβ in human cells and scoliotic tissues by RT-PCR
chondrcytes
GAPDH
ERα
ERβ
Patient A
GAPDH
ERα
ERβ
Patient B
GAPDH
ERα
ERβ
MG-63
GAPDH
ERα
ERβ

9. Relevance of this RFLP study
Statistically related to curve progression in Japanese population (right thoracic) (Inoue et al. 1996)
These RFLP are located in an intron
Will not be expressed in the a.a. sequence
May affect transcription factors binding
RFX1 for example which also binds to growth factors promoters
May affect the splicing
Alternative splicing…
Ex.: 66kDa and 46kDa

10. Conclusion & Perspectives
A lot is left to investigate…
ERα and ERβ was detected in osteoblasts but…
What modulates them remains to be ascertain
The full impact of those receptors on the scoliotic bone is still unclear
The nuclear action of Estrogens has been well studied but there are evidence of non-nuclear action that should be investigated
Detected the polymorphism in our population.
Only on a small scale
Correlate the presence of the polymorphism and ERα levels