1. Basal Cell Carcinoma and Patched

2. Basal Cell Carcinoma is the most common skin cancer, and possibly the most common cancer of all

3. Normal Skin Cells
Basal Cell Carcinoma

4. Like most skin cancers, BCC is primarily caused by sun exposure, specifically UVB rays
These rays cause mutations in DNA including deletions and substitutions

5. The Patched gene is a tumor suppressor, like Retinoblastoma
Therefore, both copies of Patched must be mutated in order to cause a tumor

6. Nevoid Basal Cell Carcinoma is the inherited form of the patched mutation, and results in tumor formation in many tissues

7. The Sonic Hedgehog-Patched Pathway
Shh
Ptch
Smo
Cytoplasm
Microtubules
Gli1
Nucleus

8. The Sonic Hedgehog pathway is involved in many processes, most importantly in midline patterning and dorsal-ventral nervous system development
scitech.html

9. Veratrum californicum (California False Hellebore)
Contains an alkaloid called cyclopamine
Cyclopamine binds directly to Smo and inhibits the Shh pathway
imaxxmln.htm

10. Cyclopia in sheep
muvetmed.agr.iwate-u.ac.jp/.../ tenji/tenji9.html

11. When Ptch is mutated, it turns the pathway on without binding Shh- more patched is transcribed
Smo
Cytoplasm
Microtubules
Gli1
Nucleus

12. Possible Treatments Cyclopamine, and is currently in clinical trials
Patched itself can also inhibit this pathway, and has been effective in mice with BCC