# Presentation: 509367

## Endocrine Disruptor Screening Program: Tier 1 Screening Battery (T1S)The ability of the T1 Battery to detect lower potency, environmentally relevant EDCs

**FIFRA Scientific Advisory Panel Meeting**
**26 March 2008**

## EPA Proposed Tier 1 Screening Battery

- Steroidogenesis (*in vitro*)
- Estrogen receptor binding assay *(in vitro)*
- Estrogen transcriptional activation assay (*in vitro)*
- Androgen receptor binding assay (*in vitro*)
- Aromatase (*in vitro)*
- Uterotrophic assay
- Hershberger assay
- Pubertal female assay
- Pubertal male assay
- Amphibian metamorphosis assay
- Fish short-term reproduction assay

## Screens and EAT systems interaction

|  |  |  |  |  | Steroid | Synthesis |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  | E | E- | A | A- | T | E | HPG | HPT |
| In vitro |  |  |  |  |  |  |  |  |
| ER Binding | X | X |  |  |  |  |  |  |
| ER Transcriptional Activation | X |  |  |  |  |  |  |  |
| AR Binding |  |  | X | X |  |  |  |  |
| Steroidogenesis (H295R) |  |  |  |  | X | X |  |  |
| Aromatase (Recombinant) |  |  |  |  |  | X |  |  |
| In vivo |  |  |  |  |  |  |  |  |
| Uterotrophic | X |   |  |  |  |  |  |  |
| Hershberger |  |  | X | X |  |  |  |  |
| Pubertal male |  |  | X | X | X |  | X | X |
| Pubertal female | X | X |  |  |  | X | X | X |
| Fish Reproductive Screen | X | X | X | X | X | X | X |  |
| Amphibian Metamorphosis |  |  |  |  |  |  |  | X |

***How environmentally relevant chemicals behave in the EDSP Tier 1 Screening battery:  Unique contributions of some assays and the emergence of WOE ***

|           Estrogens - etc | Estrogen | Estrogen +
Weak antiAR  | Estrogen
Nephrotoxic | SERM antagonist |
| --- | --- | --- | --- | --- |
|  | EE
PiE | Methoxychlor
insecticide | BPA
Plastic  | Tamoxifen
PiE |
| ER Binding | +++ | + | ++ | ++ |
| ER Transcriptional Activation | +++ | + | ++ | ++ |
| AR Binding | + | + | + |  |
| Steroidogenesis (H295R) or etc |  |  |  |  |
| Aromatase (Recombinant) |  |  |  |  |
| Uterotrophic | +++ | + | + | + |
| Hershberger | + |  |  |  |
| Pubertal male |  | NO? | NO |  |
| 
Pubertal female | 
+++ | 
++++ | 
NO | +++ VO
 reduced Uterine wt |
| Fish Reproductive Screen | +++ | ++ | + | --VTG |
| Amphibian Metamorphosis |  |  |  |  |

|      Androgen action | Androgen
AR agonist | AR antagonist
etc | AR antagonist
etc | AR antagonist |
| --- | --- | --- | --- | --- |
|  | Trenbolone
PiE | Linuron
herbicide | p,p’ DDE
insecticide | Vinclozolin
fungicide |
| ER Binding |  |  |  |  |
| ER Transcriptional Activation |  |  |  |  |
| AR Binding | +++ | + | + | +- |
| Steroidogenesis (H295R) |  |  |  |  |
| Aromatase (Recombinant) |  |  |  |  |
| Uterotrophic sc |  |  |  |  |
| Hershberger | +++ | ++ | ++ | +++ |
| Pubertal male | +++ | ++ | + | ++ |
| Pubertal female |  |  |  |  |
| Fish Reproductive Screen | +++ |  |  | + |
| Amphibian Metamorphosis |  |  |  |  |

|          Steroidogenesis
and etc | Steroid
Synthesis | Steroid
Synthesis 
and etc | Aromatase
Inhibitor
and etc | Phthalate
“anti-
Androgen” |
| --- | --- | --- | --- | --- |
|  | Ketoconazole

Fungicide | Prochloraz

fungicide | Fenarimol

fungicide | Dibutyl
Phthalate
plasticizer |
| ER Binding |  |  | + |  |
| ER Transcriptional Activation |  |  |  |  |
| AR Binding |  |  | + |  |
| Steroidogenesis (H295R) | ++ | +++ | ++ |  |
| Aromatase (Recombinant) | ++ | +++ | + |  |
| Uterotrophic sc |  |  | + |  |
| Hershberger |  |  | + |  |
| Pubertal male | + | + | ? | +++ |
| Pubertal female | + | ??? | NO |  |
| Fish Reproductive Screen | +testis
Histo only | +++ | YES |  |
| Amphibian Metamorphosis |  |  |  |  |

| HPG
Thyroid | HPG | Thyroid
agonist | Antithryoid and AR antagonist | Deiodinase
inhibitor | “Toxic Negative” |
| --- | --- | --- | --- | --- | --- |
|  | Thiram
fungicide | T4
Hormone | PBDE 71
flame retardant | Iopanoic
medical | 2 chloro nitrobenzene |
| ER Binding |  |  |  |  |  |
| ER TA |  |  |  |  |  |
| AR Binding |  |  | + |  |  |
| Steroidogenesis (H295R) or etc |  |  |  |  |  |
| Aromatase (Recombinant) |  |  |  |  |  |
| Uterotrophic sc |  |  |  |  |  |
| Hershberger |  |  | + |  |  |
| Pubertal male | ++ | TSH, histo?  | + PPS
+T4 | +? | ++ |
| Pubertal female | ++ | TSH, histo? |  | +? | ++ |
| Fish Reproductive Screen | Prob+ |  |  |  |  |
| Amphibian Metamorphosis |  | ++++++ | ? | +++++ |  |

## Clarifying issues related to the specificity of the pubertal assays

- Acceleration of PPS in male and increases in androgen-dependent organ weights are not confounded by reductions in the growth of the male
- Similarly, acceleration of VO, age at first estrus, vaginal cornification induced by estrogens or HPG stimulation are not confounded by reductions in the growth of the female
- “Alternative” statistical methods that allow one to discriminate the effects of growth on the pubertal assays exist and should be employed.

## Slide 12