Immunohistochemical Expression of Epidermal Growth Factor Receptor (EGFR) in Oral Squamous Cell Carcinoma and Oral Potentially Malignant Disorders.

BACKGROUND: Increased epidermal growth factor receptor (EGFR) expression has been implicated in several tumors and is associated with increased tumor advancement as well as a potential drug target. The objective of the study was to compare the immunohistochemical expression of EGFR in oral squamous cell carcinoma (OSCC) with oral potentially malignant disorders (OPMDs) and their demographic and pathologic parameters. METHODS: This study was a comparative cross-sectional analytical study. It was conducted at the Department of Pathology, Peshawar Medical College, Riphah International University, Islamabad, Pakistan, from March 2021 to February 2022. The sample size was calculated through G Power. Thirty-eight cases of oral squamous cell carcinoma and 38 cases of oral potentially malignant disorders (OPMDs) were included in the study. Statistical analysis was performed using the Statistical Package for Social Sciences version 20.0. χ 2 tests and Fisher exact tests were applied to compare categorical variables. RESULTS: Mean age of OSCC was 61.6±13.9, with age range from 26 to 90 years. The male-to-female ratio for OSCC was 2.16:1. Buccal mucosa was the most common site involved (34.2%). The most common histologic type was well-differentiated OSCC (71.05%) followed by poorly differentiated (16%) and moderately differentiated (13.15%). The mean age of OPMDs cases was 59.16 ± 10.81 with a male-to-female ratio of 1:1.2. Buccal mucosa was the common site (55.3%), followed by the tongue (18.4%). The OPMDs with dysplasia were 55.2%, and without dysplasia were 44.8%. A total of 55.7% of cases of OSCC showed positive EGFR expression as compared with 36.9% OPMDs cases. A higher number of low-grade OSCC cases showed increased EGFR positivity (59.3%) as compared with high grade (45.45%). EGFR positivity in OPMD cases without dysplasia was 41.2% as compared with cases with dysplasia (33.3%). The EGFR expression in OPMD cases was higher in the ≤50 age group ( P =0.001) and in females ( P =0.032), which was statistically significant. CONCLUSIONS: EGFR expression by Immunohistochemistry may not be a helpful prognostic marker to determine the risk of OPMDs progressing to higher grades of dysplasia or invasive cancer. However, further studies relating this tumor marker to stage, lymph node metastasis, hematogenous metastasis, survival outcomes, and treatment response may give useful information regarding the utility of this marker.

Visual Function is Gradually Restored During Retina Regeneration in Adult Zebrafish.

In comparison to mammals, zebrafish are able to regenerate many organs and tissues, including the central nervous system (CNS). Within the CNS-derived neural retina, light lesions result in a loss of photoreceptors and the subsequent activation of Müller glia, the retinal stem cells. Müller glia-derived progenitors differentiate and eventually restore the anatomical tissue architecture within 4 weeks. However, little is known about how light lesions impair vision functionally, as well as how and to what extent visual function is restored during the course of regeneration, in particular in adult animals. Here, we applied quantitative behavioral assays to assess restoration of visual function during homeostasis and regeneration in adult zebrafish. We developed a novel vision-dependent social preference test, and show that vision is massively impaired early after lesion, but is restored to pre-lesion levels within 7 days after lesion. Furthermore, we employed a quantitative optokinetic response assay with different degrees of difficulty, similar to vision tests in humans. We found that vision for easy conditions with high contrast and low level of detail, as well as color vision, was restored around 7-10 days post lesion. Vision under more demanding conditions, with low contrast and high level of detail, was regained only later from 14 days post lesion onwards. Taken together, we conclude that vision based on contrast sensitivity, spatial resolution and the perception of colors is restored after light lesion in adult zebrafish in a gradual manner.