title: Connexin subtype expression during oral carcinogenesis: A pilot study in patients with oral squamous cell carcinoma.
abstract: Gap junctional intercellular communication (GJIC) and connexin (Cx) expression were reported in association with carcinogenesis in various types of tumours. In an earlier histomorphometric study, the protein levels of Cx subtypes 26, 43 and 45 were differentially expressed in oral squamous cell carcinoma (OSCC), corresponding lymph node metastases and dysplasia-free oral mucosa. Moreover, membrane Cx43 acted as an independent prognostic marker in OSCC tissues. This study aimed to confirm the expression of described Cx subtypes at the mRNA level. Hence, a reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis of Cx26, Cx43 and Cx45 gene expressions was performed in paired carcinoma and mucosa samples of 15 OSCC patients. Additionally, we assessed the interaction between Cx subtype expression and clinicopathological routine parameters. The RT-qPCR analysis revealed that Cx26 was downregulated in OSCC (P=0.01), while Cx43 was marginally upregulated in cancer tissue (P=0.04). Cx45 was significantly overexpressed in OSCC tissue compared with the intraoral mucosa controls (P<0.01), and remained unchanged at different tumour stages. No significant interactions between differential Cx subtype expression and clinicopathological routine parameters were observed. In conclusion, Cx regulation at the transcriptional level appears to be an early event during the initiation and development of OSCC, and is maintained during further progression. However, the mRNA-protein correlation is variable. This may be indicative of post-transcriptional, translational and degradation regulations being associated with the determination of Cx protein concentration during oral carcinogenesis.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Centre Goettingen, D-37075 Goettingen, Germany.
authors.forename: Phillipp
authors.initials: P
authors.lastname: Brockmeyer
authors.affiliation: Department of Pathology, University Medical Centre Goettingen, D-37075 Goettingen, Germany; Institute of Pathology, Krefeld Helios Hospital, D-47805 Krefeld, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Hemmerlein
authors.affiliation: Department of Medical Statistics, University Medical Centre Goettingen, D-37075 Goettingen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Jung
authors.affiliation: Private Practice, MKG Leinetal, D-37574 Einbeck, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Fialka
authors.affiliation: Private Practice, Zahnarztpraxis am Westertor, D-37115 Duderstadt, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Brodmann
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Centre Goettingen, D-37075 Goettingen, Germany.
authors.forename: Rudolf Matthias
authors.initials: RM
authors.lastname: Gruber
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Centre Goettingen, D-37075 Goettingen, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Schliephake
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Centre Goettingen, D-37075 Goettingen, Germany.
authors.forename: Franz-Josef
authors.initials: FJ
authors.lastname: Kramer
keywords: connexin 26; connexin 43; connexin 45; connexin regulation; gap junctional intercellular communication; oral squamous cell carcinoma