COMPARATIVE EXPRESSION OF TOLL-LIKE RECEPTOR 4 IN ORAL PAPILLARY AND CONVENTIONAL SQUAMOUS CELL CARCINOMA USING RT-QPCR AND IMMUNOHISTOCHEMISTRY (COMPARATIVE CROSS- SECTIONAL STUDY)

Background:Oral papillary squamous cell carcinoma (OPSCC) is a rare subtype of squamous cell carcinoma with
debatable prognosis and metastatic potential. To better understand this neoplasm, it is essential to investigate its
biological behavior, growth patterns, and tumor microenvironment. Our study aims to compare the expression of tolllike receptor 4 in papillary and various grades of conventional squamous cell carcinoma.
Materials & Methods:This comparative cross-sectional study included formalin-fixed paraffin-embedded samples of
different grades of conventional squamous cell carcinoma, OPSCC, and normal epithelial tissue as a control group.
TLR4 mRNA levels were evaluated using RT-qPCR, while protein expression was assessed by immunohistochemical
staining. Statistical analysis was performed to compare expression between the groups.
Results: TLR4 exhibited cytoplasmic and variable nuclear expression in both OSCC and OPSCC, with the highest levels found in poorly differentiated SCC. RT-qPCR confirmed significantly elevated TLR4 mRNA in all cancer groups
compared to controls. No statistically significant differences in TLR4 expression were observed between OPSCC and
well-differentiated or moderately differentiated squamous cell carcinoma in either immunohistochemical or PCR
analysis.
Conclusion:The results indicate that while OPSCC may display unique biological characteristics compared to
conventional OSCC, its behavior appears to resemble that of OSCC with similar histological grading, regardless of
connective tissue invasion.