Claudin3 is localized outside the tight junctions in human carcinomas

Area of Science:

• Molecular Biology
• Oncology
• Biochemistry

Background:

• Claudin3 is a key component of tight junctions in polarized epithelial cells.
• Tight junctions are crucial for maintaining epithelial barrier integrity.
• Dysregulation of tight junction proteins is implicated in carcinogenesis.

Purpose of the Study:

• To investigate the role and expression patterns of Claudin3 in epithelial-derived tumors.
• To identify gene alterations associated with Claudin3 during cancer development.
• To explore the potential of Claudin3 as a therapeutic and diagnostic target.

Main Methods:

• Utilized the Oncomine database to assess Claudin3 expression in various tumors.
• Employed cBioPortal to analyze copy number alterations and mutations of Claudin3.
• Performed 3D reconstruction and immunofluorescence analysis on tissue samples.

Main Results:

• Claudin3 overexpression was observed in gynecological, bladder, breast, and prostate carcinomas.
• Gene alterations, including mutations and/or amplification, were found in 38% of evaluated studies.
• Immunofluorescence revealed Claudin3 mislocalization and lack of tight junction engagement in tumor tissues compared to healthy tissues.

Conclusions:

• Aberrant Claudin3 expression and localization in tumors highlight its altered role in carcinogenesis.
• Unengaged Claudin3 presents a promising target for developing novel diagnostic probes and therapeutic agents.
• Real-time optical detection of tumoral tissues during surgery could be facilitated by targeting Claudin3.