RCAS1 expression in mobile tongue squamous cell carcinoma: an immunohistochemical study

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.

Apoptotic function of tumor-associated antigen RCAS1 in oral squamous cell carcinoma

Background

Receptor-binding cancer antigen expressed on SiSo cell (RCAS1) is derived from uterine adenocarcinoma and can induce apoptosis in lymphocytes, allowing tumor cells to escape from immune surveillance. RCAS1 is reportedly expressed in a membranous pattern on tumor cell or soluble one in serum of patients. The aim of this study was to investigate expression patterns of RCAS1 and the effect on apoptosis in oral squamous cell carcinoma (OSCC) cell lines.

Methods

In four kinds of OSCC cell lines (HSC-2, HSC-3, SQUU-A, and SQUU-B), RCAS1 mRNAs and proteins were determined by RT-PCR and immunocytochemistry. Membranous RCAS1 was determined by flow cytometry. Culture supernatants were analyzed for detection of soluble RCAS1 by dot blotting and enzyme-linked immunosorbent assay. Apoptotic ability of RCAS1 on the erythroid leukemia cell line K562 with the putative receptor was evaluated by flow cytometry in co-culture with highly metastatic SQUU-B, with knocked-down RCAS1 cells or in a no-cell contact condition.

Results

RCAS1 mRNA and proteins were expressed in all of OSCC cell lines. Membranous pattern were expressed in all cell lines, while soluble pattern was detected in all supernatants. RCAS1 mRNA, membranous and soluble RCAS1 were significantly seen in SQUU-B more than the other 3 cell lines (P < 0.05). K562 apoptosis was induced in co-culture with each of all cell lines, particularly with SQUU-B. Apoptosis was markedly reduced in co-culture with RCAS1 knockdown cells, but was induced in co-culture without cell contract of SQUU-B.

Conlusions

Our study suggests that RCAS1 has an apoptotic function via membranous/soluble expression pattern in OSCC cells. RCAS1 may thus affect tumor escape from immune surveillance in OSCC by inducing apoptosis.

Investigations on the clinical significance of FOXP3 protein expression in cervical oesophageal cancer and the number of FOXP3+ tumour-infiltrating lymphocytes

OBJECTIVES

Investigations of FOXP3 protein expression in cervical oesophageal cancer cells and the number of FOXP3 + lymphocytes infiltrating tumour tissue were undertaken.

METHODS

FOXP3 protein expression and FOXP3 + tumour-infiltrating lymphocytes were studied immunohistochemically, in cervical oesophageal cancer tissue samples from 42 cases and paracancerous tissue samples from 30 of these cases.

RESULTS

The percentage of parenchymal cells expressing FOXP3 protein was significantly higher in cancer tissue (42.9%, 18/42) than in paracancerous tissue 6.67% (two of 30). FOXP3 + lymphocyte infiltration was significantly more frequent in cancer (38.1%, 16/42) than in paracancerous (13.33%, four of 30) tissue. FOXP3 protein expression in cancer parenchymal cells in patients with lymph node metastasis was significantly greater than expression in those without lymph node metastasis. FOXP3 protein expression was significantly higher in cancer tissue samples from clinical stage III or IV than those from stage I or II disease. FOXP3 + lymphocyte infiltration of tumours was significantly greater in patients with lymph node metastasis than in those without metastasis.

CONCLUSIONS

Abnormal FOXP3 expression in cervical oesophageal cancer parenchyma and FOXP3 + lymphocyte infiltration might be closely related to metastasis of this cancer by promoting immune escape of the tumour. FOXP3 might be a potential marker for the assessment of postoperative metastasis in cervical oesophageal cancer.