Related Experiment Video
Updated: Sep 26, 2026

Development of Compendium for Esophageal Squamous Cell Carcinoma
Published on: April 12, 2024
Overexpression of cell cycle regulatory proteins correlates with advanced tumor stage in head and neck squamous cell
Dan C Nguyen1, Behdad Parsa, Abby Close
1Center for Craniofacial Molecular Biology, Los Angeles, CA, USA.
Abstract:
Squamous cell carcinoma of the head and neck region (HNSCC) is the sixth most frequent cancer worldwide. In the USA, 30,000 new cases and 8,000 deaths are reported each year. Differences between normal epithelium and cancer cells from the upper aerodigestive tract arise from alterations in expression of specific genes controlling proliferation and immortalization. The protein products of these genes include growth factor receptors, cell cycle regulators, and tumor suppressors which affect a variety of intracellular signaling pathways. To determine how altered expression of these gene products contribute to HNSCC progression, we examined expression of epidermal growth factor receptor (EGFR), cyclins, p16INK4A, c-myc, proliferating cell nuclear antigen (PCNA), and telomerase in archival pathology specimens by immunohistochemistry. A substantial majority of HNSCC tumors showed loss of p16INK4A expression and dramatic overexpression of EGFR. Overexpression of this receptor correlated with increased cyclin A levels and high mitotic index. EGFR, cyclins A, -B1, -E, and c-myc overexpression was significantly increased in stage III and IV tumors compared to early stage cancers. hTERT was expressed in all tumors and primarily in the basal layer cells of dysplastic epithelial lesions. Suprabasal expression of hTERT was found in a significantly higher number of HNSCC cases than in dysplastic lesions. These results indicate that overexpression of cell cycle regulatory proteins correlates with advanced tumor stage in HNSCC.
Related Concept Videos
Positive Regulator Molecules
Positive Regulator Molecules
Negative Regulator Molecules
Molecular Factors Affecting Cell Division
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...
mTOR Signaling and Cancer Progression
The mTOR pathway or the...
mTOR Signaling and Cancer Progression
The mTOR pathway or the...