Greater expression of TC21/R-ras2 in highly aggressive malignant skin cancer

TC21 plays an important role in highly aggressive tumor formation, and it was overexpressed in several human cancers, including breast cancer, oral squamous cell carcinoma (SCC), and esophageal SCC. In light of this, we explored the expression of TC21 in overall skin cancers in order to evaluate the relationship between TC21 and malignant skin tumors.

We examined six normal skin tissues and 18 malignant skin tumor tissues, including six malignant melanomas (MM), six SCCs, and six basal cell carcinomas (BCCs) using western blotting for the expression of TC21. In another set, 16 specimens of MM, 16 SCC, and 16 BCC were analyzed for the expression of TC21 using immunohistochemical staining. To evaluate the amount of expression of TC21, the Raytest TINA software was used for western blotting and a histochemical score (HSCORE) was used for immunohistochemical evaluation.

The western blotting and immunohistochemistry showed that TC21 was expressed in all malignant skin tumors and not in normal skin tissues. The relative protein expression was an average of 0.004 in normal skin, 1.042 in MM, 0.621 in SCC, and 0.485 in BCC. In immunohistochemistry, HSCORE for normal skin was an average of 0.05, MM was 2.42, SCC was 2.11, and BCC was 1.22.

This article is the first study demonstrating expression of TC21 in human skin malignant tumors and suggests that TC21 is more expressed in highly aggressive skin tumors.