Expression of connexin-43 in surgical resections of primary tumor and lymph node metastases of squamous cell carcinoma and adenocarcinoma of the lung: a retrospective study

Expression of Connexin 43 in Granular Cell Tumors of the Skin, Tongue and Esophagus

BACKGROUND

Granular cell tumors (GCT) are rare neoplasms of Schwann cell origin occurring in the skin and in other organs. The etiopathogenesis of GCT is yet poorly understood. Connexin 43 (Cx43) is the most broadly expressed gap junction protein in humans, the tumoral role of which has been investigated in several types of tumors. Its role in GCT of the skin, oral cavity and gastrointestinal tract is as yet unknown.

METHODS

Herein, we present a study on the immunohistochemical expression of Cx43 in GCT of the skin (n = 15), tongue (n = 4) and esophagus (n = 3). Immunolabeling was scored positive (weak (+), moderate (++) or strong (+++)).

RESULTS

Cx43 was expressed by all cases of GCT of the skin, tongue and esophagus (22/22), showing moderate to strong staining. All tissue sections of GCT were characterized by a diffuse, cytoplasmic staining pattern of the tumor cells. None of those showed membranous or nuclear staining.

CONCLUSION

Our results suggest that Cx43 probably plays an important role in the development of this rare tumor entity.

Role of gap junctions and connexin 43 in cancerogenesis and tumor metastasis

Gap junctions are intercellular connections that enable direct communication between neighboring cells. They are important in tissue homeostasis, cell growth, and differentiation. They are composed of connexin proteins, of which the most common and most studied is connexin 43. The role of connexin 43 in the development and progression of tumors is contradictory. The aim of this paper is to summarize the current state of knowledge on the expression of connexin 43 in various primary and secondary tumors, in order to explain its role in the development and progression of malignant tumors. Previous studies have examined the expression of connexin 43 in various primary and secondary tumors, as well as its association with prognosis. The expression of connexin 43 has been shown to be associated with various aspects of tumor behavior. However, it has been shown that the expression of connexin 43 differs between different types and localizations of tumors, as well as between different stages in tumor progression, which indicates the complex role of connexin 43 in tumor evolution. Since gap junctions play a role in carcinogenesis, invasion, and metastasis of malignant cells, further studies should clarify whether connexin 43 can be used as a diagnostic biomarker.