Immunohistochemical analysis of EGFR and hyaluronan in tongue cancer and the development of regional recurrence in patients initially diagnosed N0

Expression and clinical significance of the receptors of the EGF family in oral squamous cell carcinomas

Objective:

To examine the immunohistochemical expression of four members of the type 1 growth factor receptor family in oral squamous cell carcinomas (OSCCs) and to correlate with clinical outcomes.

Materials and methods:

Sixty OSCCs from a patient cohort in Sri Lanka were included in the study. Five sections from each carcinoma were immunostained with antibodies to epidermal growth factor receptor (EGFR)/c-erbB-1, c-erbB-2/HER-2/neu, c-erbB-3/HER-3 and c-erbB-4/HER-4. Two clones were used to stain for c-erbB-2/HER-2/neu. Semiquantitative analysis of immunoreactivity was carried out by scoring the intensity of expression and proportions of positively stained cells. A logistic regression analysis was performed to examine positive expression against overall survival.

Results:

There was heterogenous expression of the four receptors, positivity ranging from 26% to 60%. Co-expression of all four markers was observed only in 1–3% of the tumours. Both membranous and cytoplasmic expressions were observed, EGFR showing predominantly membranous expression and c-erbB-2 showing only cytoplasmic staining. In logistic regression analysis, none of the growth factor receptors were significantly predictive of overall survival.

Conclusion:

Type 1 growth factor receptors are highly expressed in oral carcinomas, EGFR being the predominant marker.

A review of the most promising biomarkers for early diagnosis and prognosis prediction of tongue squamous cell carcinoma

BACKGROUND

There is a great interest in developing biomarkers to enhance early detection and clinical management of tongue squamous cell carcinoma (TSCC). However, the developmental path towards a clinically valid biomarker remains extremely challenging. Ideally, the initial key step in moving a newly discovered biomarker towards clinical implementation is independent replication. Therefore, the focus of this review is on biomarkers that consistently showed clinical relevance in two or more publications.

METHODS

We searched PubMed database for relevant papers across different TSCC sample sources, i.e., body fluids (saliva, serum/plasma) and tissues. No restriction regarding the date of publication was applied except for immunohistochemistry (IHC); only studies published between 2010 and June 2017 were included.

RESULTS

The search strategy identified 1429 abstracts, of which 96 papers, examining 150 biomarkers, were eventually included. Of these papers, 66% were exploratory studies evaluating single or a panel of biomarkers in one publication. Ultimately, based on studies that had undergone validation for their clinical relevance in at least two independent studies, we identified 10 promising candidates, consisting of different types of molecules (IL-6, IL-8, and Prolactin in liquid samples; HIF-1α, SOX2, E-cadherin, vimentin, MALAT1, TP53, and NOTCH1 in tissue biopsies) CONCLUSIONS: Although more exploratory research is needed with newer methods to identify biomarkers for TSCC, rigorous validation of biomarkers that have already shown unbiased assessment in at least two publications should be considered a high priority. Further research on these promising biomarkers or their combination in multi-institutional studies, could provide new possibilities to develop a specific panel for early diagnosis, prognosis, and individualized treatments.

Long noncoding RNA Lnc‑EGFR promotes cell proliferation and inhibits cell apoptosis via regulating the expression of EGFR in human tongue cancer

Tongue cancer remains a difficult disease to overcome. Long noncoding RNAs (LncRNAs) have been shown to serve significant roles in the diagnosis and treatment of tongue cancer. Herein, the present study aimed to investigate the role of a newly‑discovered Lnc, Lnc‑EGFR in tongue cancer. The results showed that the transcript level of Lnc‑EGFR was upregulated in patients with tongue cancer and in cultured tongue cancer cell lines. Consistently, expression of EGFR was also elevated selectively in cancerous tissues and malignant cell lines. Knockdown of Lnc‑EGFR inhibited the clonogenic ability and cell viability of human tongue cancer cell lines UM1 and CAL‑27, as evidenced by colony formation assays, and cell proliferation assays. Furthermore, depletion of Lnc‑EGFR in UM1 and CAL‑27 cells increased cell apoptosis by upregulating the activities of caspase‑3, and caspase‑9, but not caspase‑8. Lnc‑EGFR knockdown‑mediated inhibition of clonogenic ability and cell viability was rescued by overexpression of EGFR by adding EGFR recombinant protein into both cell lines. Likewise, Lnc‑EGFR knockdown‑induced cell apoptosis was reversed by co‑treatment with recombinant EGFR protein in UM1 and CAL‑27 cells. All of these results suggested the oncogenic potential of Lnc‑EGFR, which was achieved by positive regulation of EGFR in human tongue cancer.