Homozygous deletion of the PTEN tumor-suppressor gene is not a feature in oral squamous cell carcinoma

A recently identified putative tumor-suppressor gene, PTEN, at 10q23 has be en described as mutated or homozygously deleted in many different human tum ors. To determine the role of the homozygous deletion of this PTEN gene in oral squamous cell carcinoma (OSCC), we screened two cell lines derived fro m the latter tissue and 28 tumor samples from patients with OSCC, using a d ifferential display polymerase chain reaction (PCR) system and, direct DNA sequencing methods. All of the nine exons of the PTEN could be successfully amplified using DNA from tumor tissues and the cell lines using this syste m. DNA sequencing confirmed the accuracy of the PCR procedures. However, no ne of the samples, either from the cancer tissues or from the cell lines, s howed homozygous deletion of PTEN. These data suggest that homozygous delet ion of the PTEN gene is unlikely to be a feature of OSCCs. (C) 2000 Elsevie r Science Ltd. All rights reserved.