Expression of ABCG2 and Bmi‐1 in oral potentially malignant lesions and oral squamous cell carcinoma

Abstract

Early diagnosis is vital for effective treatment of oral squamous cell carcinoma (OSCC). The optimal time for clinical intervention is prior to malignancy when patients present with oral potentially malignant lesions such as leukoplakia or erythroplakia. Transformation rates for oral dysplasia vary greatly and more rigorous methods are needed to predict the malignant potential of oral lesions. We hypothesized that the expression of two putative stem cell markers, ABCG2 and Bmi-1, would correlate with disease severity for non diseased, potentially malignant and OSCC specimens and cell lines derived from an equivalent range of tissues. We compared immunoreactive protein and relative gene expression of ABCG2 and Bmi-1 in eight cell lines derived from source tissues ranging in disease severity from normal (OKF6-TERT2) through mild and moderate/severe dysplasia (DOK, POE-9n) to OSCC (PE/CA-PJ15, SCC04, SCC25, SCC09, SCC15). We also analyzed immunoreactive protein expression of ABCG2 and Bmi-1 in 189 tissue samples with the same range of disease severity. A trend between oral lesion severity to ABCG2 and Bmi-1 immunostain intensity was observed. Flow cytometry of oral cell lines confirmed this trend and gave good correlation with RT-PCR results for ABCG2 (r = 0.919, P = 0.001; Pearson) but not Bmi-1 (r = −0.311). The results provide evidence of increased density of ABCG2 and Bmi-1-positive populations in malignant and oral potentially malignant lesions and derived cell lines, but that intragroup variability within IHC, flow cytometry, and RT-PCR results compromise the diagnostic potential of these techniques for discriminating oral dysplasia from normal tissue or OSCC.

Prognostic implications of CD44, NANOG, OCT4, and BMI1 expression in tongue squamous cell carcinoma

“…Here, we found higher expression levels of BMI1 mRNA in tongue SCC in relation with nontumoral margins as well as strong BMI1 protein expression in 23 of 60 tongue SCC samples (38.33%). As expected, BMI1 was occasionally expressed in normal epithelial cells, mainly in the basal layer, corroborating the results observed by Dalley et al and Kang et al…”

Immunoexpression of SOX‐2 in oral leukoplakia

“…Knowledge of the molecular mechanisms involved in the malignant transformation of OL lesions is fundamental for developing less invasive and more effective therapies, as there is no effective resource that to prevent malignant transformation (Liu, Lin et al., ; Liu, Wu et al., ). Among the several markers described in the literature, those of cancer stem cells in OL lesions have been highlighted (Dalley, Pitty, Major, AbdulMajeed, & Farah, ; Kiyosue et al., ; Liu et al., ; Liu, Lin et al., ; Liu, Wu et al., ; Mack & Gires, ; Quiao et al., 2014; Zhang et al., ). The tumor stem cell theory describes that only a small group of tumor cells are capable of initiating and perpetuating the growth of the tumor, even when the patient is undergoing treatment, such as cisplatin chemotherapy (Braakhuis, Leemans, & Brakenhoff, ; Reers, Pfannerstill, Maushagen, Pries, & Wollenberg, ).…”

Secretory leukocyte peptidase inhibitor expression and apoptosis effect in oral leukoplakia and oral squamous cell carcinoma

“…IHC staining. The FFPE specimens were cut in 5-µm tissue sections and then used for IHC as previously described (27,28). The slides were incubated overnight at 4˚C with primary antibody diluted in primary antibody diluent (Beyotime Institute of Biotechnology, Beijing, China).…”