Cell signalling pathways

Question 1

When does phosphorylation only occur?

Answer 1

On serine, Threonine and Tyrosine residue reversible

Question 2

the majority of oral cancer is?

Answer 2

Squamous cell carcinoma

Question 3

Growth factors in OSCC

Answer 3

Epidermal growth factor (EGF) and Transforming growth factor alpha (TGF-α) (most common)
➢ Promotes cell proliferation in oral tissues
➢ Overexpressed in oral carcinogenesis
➢ Overexpressed in 80-90% OSCC
➢ Stimulates target cell by binding to the epidermal growth factor receptor (EGFR)
➢ EGFR protein is overexpressed in 40-50% HNSCC
➢ Salivary EGF- Oral tissue integrity

Question 4

VEGF (vascular endothelial growth factor)

Answer 4

➢ Plays important role in angiogenesis
➢ Angiogenesis is indispensable for the proliferation and metastasis of solid tumours,
including head and neck squamous cell carcinoma.
➢ Binds with VEGF receptor 1,2, and 3
➢ The percentage of VEGF-positive OSCC cases differs from 25% to 100% with mean
positivity of 78%
➢ Several studies have shown that overexpression of VEGF is associated with worse
survival