Bile acids and Barrett’s DiseaseBile acids and Barrett’s Disease

And the case of the efficient Japanese!

Barrett’sBarrett’s• 1950 Norman Barrett• Pre-malignant Condition

– Oesophageal Cancer

• Definition• Causes

– Age and Gender– Smoking and Alcohol– Gastro Oesophageal Reflux (GORD)– Duodenogastro Oesophageal Reflux

(DGOR)

GORD/DGORGORD/DGOR• What Causes? Defective Sphincter

Hiatal hernia Delayed gastric emptying Over production of acid Helicobacter pylori

• BackwashAcidBile

• Why? Defence Mechanism Oesophageal (weak) Squamous

Stomach (STRONG) Glandular More Resistant to Acid

Acid/Bile Acid/Bile RefluxReflux © Altana

What's Known?What's Known?• Acid alone does not cause Barrett’s

• Mice develop Barretts when their duodenum is connected to their oesophagus

• Barrett’s patients exposed to bile and acid for long periods

• Bile and retinoic acid are potent gene regulators

• Certain genes control cell proliferation and differentiation

• CDX2 and MUC2 normally only found in Intestinal cells

• Detected in Barretts disease (Immunohistochemistry)

Cdx2Cdx2

• Cdx2 Amplified in Keratinocytes

• Lane 2 - Deoxycholate Acid (100 µM )

• Lane 4 – Deoxycholate and Retinoic Acid (100 µM and 1 µM respectively)

• Lane 6 – Cheno deoxycholate and Retinoic Acid (100 µM and 1 µM respectively)

• Lane 16 – CACO-2 cells positive control

Muc2Muc2

• Muc2 Amplified in Keratinocytes

• Lane 12 – Retinoic Acid (1µM 22hrs)

• Lane 16 – CACO-2 cells positive control

SummarySummary• Cdx2

– 48hr treatment of oesophageal keratinocytes with 2µM retinoic acid causes activation of Cdx2

– 12hr treatment of oesophageal keratinocytes with DCA/DCA and Retinoic acid/ CDCA and retinoic acid causes activation of Cdx2

• Muc2– 48hr treatment of oesophageal keratinocytes

with 2µM retinoic acid causes activation of Muc 2

– 22hr treatment of oesophageal keratinocytes with 1µM retinoic acid causes activation of Muc2

Key ResultKey Result

Bile and Retinoic acid are turning on genes that are normally only found in intestinal

cells where their function is to regulate cell proliferation and differentiation.

The JapaneseThe Japanese• Cell Culture (Rat primary keratinocytes)

– Cholic acid (100µM) turned on Cdx2 after 24hrs– Dehydrocholic acid (100µM) turned on Cdx2 after

24hrs– Transfection of Cdx2 gene into rat keratinocytes

yielded Muc2 expression

• Using 7 week old Rats– Attached rats oesophagus to jejunum– Development of columnar epithelium in

oesophagus after 6 months (Barrett’s)– Similar concentrations of cholic and

dehydrocholic acid were found in rat stomach contents as were used in cell culture experiments

Our PlanOur Plan• Paper

– DCA and Retinoic acid– Cdx2 and Muc2– Human primary keratinocytes

• Lab– Extract fresh human keratinocytes– Look at retinoic acid at higher

concentrations of 10-100µM– Hepatic circulation of up to 1M– Cdx 1 and 2 expression– RXR/RAR

Replacement of lower oesophageal squamous mucosa by metaplastic glandular epithelium as a result of gastro oesophageal reflux disease (GORD) and/or Duodenogastro Oesophageal Reflux (DGOR)

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