Neoplasia

Question 1

What is myc? What is the role of myc? How is it upregulated and in which cancers?

Answer 1

All growth factors and signalling molecules stimulate transcription factors which regulate transcription of growth promoting genes.
Myc is a transcription factor which is present in all cells during normal cell growth.
It has the following functions
1) Increases expression of growth promoting genes eg. Cyclin D1, activated rRNA processing etc
2) Causes altered cell metabolism ie. Warburg effect
3) Increases telomerase activity
4)Causes programming of somatic cells to stem cells

Mechanism of my activation:

• Genetic alteration: overexpression of myc
• Amplification: N-myc and L-myc in neuroblastoma and Lung cancer respectively
• Translocation: Eg burkitt lymphoma
• Oncogenic mutations in upstream signalling pathways which cause increased transcription of myc, or increased production of myc protein

Cancers:
Small cell Lung cancer: L-myc
Neuroblastoma: N-myc
C-myc: burkitt Lymphoma

Question 2

What are the metastatic signature genes?

Answer 2

SNAIL
TWIST
MiR 10b
EZRIN