Overexpression of Heat Shock Protein (HPS) 25 Saves Salivary Glands from Radiation Therapy Damages

Radiation-induced damage to the salivary glands is a common consequence of treatment for head and neck cancer.

Patients with head and neck cancer often receive radiation therapy as part of their treatment. However, the salivary glands, which frequently reside within the irradiation field, can become damaged at the same time.

The resulting salivary dysfunction may involve dry mouth, oral infections, dental caries, and difficulty eating, some of which persist long after treatment ends, even permanently.

Now, researchers have shown that targeted overexpression of heat shock protein 25 prevents such a damage.

In treated rats, HSP25 protected salivary gland function by maintaining gland weight, salivary flow rate, and salivary fluid composition, whereas HSP70i significantly protected only salivary flow rate.

When specific damage to the glands was assessed, HSP25 and HSP70i both greatly diminished scarring, nuclear damage, and cell death (apoptosis), but HSP70i was slightly less effective.

Finally, HSP25 and HSP70i preserved expression of aquaporin 5, which is important for water transport in salivary glands.

These findings have been reported by Lee et al. in an article entitled: “Radioprotective effect of HSP25 on submandibular glands of rats”, appearing in the November issue of The American Journal of Pathology.

Read the full report from Science Daily.