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Claudin-7 down-regulation is an important feature in oral squamous cell carcinoma

Silvia Vanessa Lourenço1, Cláudia Malheiros Coutinho-Camillo, Marcilei Elisa Cavicchioli Buim

  • 1Department of General Pathology, Dental School, University of São Paulo, São Paulo, Brazil. silvialourenco.70@terra.com.br

Histopathology
|November 19, 2010
PubMed
Abstract

Insights

Loss of claudin-7 protein expression is common in oral squamous cell carcinoma (OSCC). This down-regulation correlates with tumor size, stage, and poorer survival, suggesting claudin-7 is a key biomarker in OSCC progression.

Area of Science:

  • Oncology
  • Cell Biology
  • Molecular Biology

Background:

  • Claudins are crucial tight junction proteins frequently dysregulated in human carcinomas.
  • Claudin-7, specifically, shows altered expression patterns in various cancers, necessitating further investigation in oral squamous cell carcinoma (OSCC).

Purpose of the Study:

  • To investigate the expression status and alterations of claudin-7 in oral squamous cell carcinoma (OSCC).
  • To correlate claudin-7 expression with clinical parameters and survival outcomes in OSCC patients.

Main Methods:

  • Claudin-7 protein expression was assessed in 132 OSCC tissue microarrays.
  • Claudin-7 mRNA transcript levels were quantified using real-time polymerase chain reaction.
  • The methylation status of the claudin-7 promoter region was analyzed, with functional studies involving 5-Aza-2'-Deoxycytidine treatment.

Main Results:

  • Claudin-7 protein was found to be negative in 58.3% of OSCC cases.
  • Loss of claudin-7 expression significantly correlated with increased tumor size, advanced clinical stage, recurrence, and reduced disease-free survival.
  • Down-regulation of claudin-7 mRNA was observed in 78% of cases, and promoter methylation was identified as a mechanism for its silencing, reversible with 5-Aza-dC treatment.

Conclusions:

  • Loss of claudin-7 expression is a significant finding in OSCC.
  • Claudin-7 down-regulation is associated with critical subcellular alterations impacting key clinical parameters in OSCC.
  • Claudin-7 may serve as a prognostic biomarker for OSCC.

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