Affiliations 

  • 1 Oral Cancer Research and Coordinating Centre, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia
  • 2 Department of Oral and Maxillofacial Surgery, Hospital Kuala Lumpur, Ministry of Health Malaysia, Kuala Lumpur, Malaysia
  • 3 Department of Oral and Maxillofacial Surgery, Hospital Tengku Ampuan Rahimah, Ministry of Health Malaysia, Klang, Malaysia
  • 4 Department of Oral Surgery, Hospital Umum Sarawak, Ministry of Health Malaysia, Kuching, Sarawak, Malaysia
  • 5 Oral Cancer Research and Coordinating Centre, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia. rosnahbz12@yahoo.com
Clin Oral Investig, 2015 Dec;19(9):2273-83.
PMID: 25846277 DOI: 10.1007/s00784-015-1467-7

Abstract

OBJECTIVES: This study includes the direct sequencing of cornulin (CRNN) gene to elucidate the possible mechanism of CRNN downregulation and explore the genetic imbalances at 1q21.3 across oral squamous cell carcinoma (OSCC) samples.

MATERIALS AND METHODS: In mutation screening of CRNN gene, gDNA from OSCC tissues were extracted, amplified, and followed by direct sequencing. OSCC samples were also subjected to fragment analysis on CRNN gene to investigate its microsatellite instability (MSI) and loss of heterozygosity (LOH). Immunohistochemistry was performed to validate CRNN downregulation in OSCC samples.

RESULTS: No pathogenic mutation was found in CRNN gene, while high frequency of allelic imbalances was found at 1q21.3 region. MSI was found more frequent (25.3 %) than LOH (9.3 %). Approximately 22.6 % of cases had high MSI which reflects higher probability of inactivation of DNA mismatch repair genes. MSI showed significant association with no betel quid chewing (p = 0.003) and tongue subsite (p = 0.026). LOH was associated with ethnicity (p = 0.008) and advanced staging (p = 0.039). The LOH at 1q21.3 was identified to be as an independent prognostic marker in OSCC (HRR = 7.15 (95 % CI, 1.41-36.25), p = 0.018). Downregulation of CRNN was found among MSI-positive OSCCs and was associated with poor prognosis (p = 0.044).

CONCLUSION: This study showed a significant correlation between LOH/MSI at 1q21.3 with clinical outcomes and that downregulation of CRNN gene could be considered as a prognostic marker of OSCC.

CLINICAL RELEVANCE: Insights of the downregulation mode of CRNN gene lays the basis of drug development on this gene as well as revealing its prognostic value.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.