Osteopontin (OPN) distribution in premalignant and malignant lesions of oral epithelium and expression in cell lines derived from squamous cell carcinoma of the oral cavity

Abstract

The objectives of this study were to assess the immunolocalization of human osteopontin (OPN) in oral lesions and to identify human cell lines of oral squamous cell carcinoma (OSCC) origin that express OPN mRNA. OPN was localized using immunohistochemistry in the following oral specimens: normal epithelium (n=6), epithelial hyperplasia (n=4), epithelial dysplasia (n=28), carcinoma in situ (n=11) and squamous cell carcinoma (n=43). Cell lines UMSCC‐1, MDA TU 138, MDA 686LN, SCC4, SCC9, SCC25, CAL 27 and MDA 1483 were characterized for OPN mRNA expression using Northern blotting. OPN was not detected in normal oral epithelium. Intracellular and intercellular immunore‐activity was seen in 75% of hyperplasias, 57% of dysplasias, 54% of carcinoma in situ and 67% of squamous cell carcinomas. UMSCC‐1 expressed high levels of OPN mRNA. We conclude that OPN protein is detectable in premalignant and malignant lesions arising from oral epithelium. UMSCC‐1 may be a useful cell line in which to conduct in vitro studies designed to clarify the role of OPN in OSCC.

Expression of Osteopontin in Oral Squamous Cell Carcinoma and its Surgical Margins-An Immunohistochemical Study

“…In OSCC samples (group II A), 95% of cytoplasmic & membrane immunoreactivity was observed in the tumour islands [Table/ Fig-1a-d]. These results were in accordance with the findings of Devoll et al, who reported significant percentage of OPN expression in cell lines derived from OSCC [18]. However, one case of OSCC in our study showed negative immunoreactivity for OPN.…”

“…There was a negative expression of OPN in all the 20 samples of normal oral mucosa [Table/ Fig-3a&b]. A similar expression was also seen in the studies conducted by Devoll et al, & Zhou et al, [18,19]. In OSCC samples (group II A), 95% of cytoplasmic & membrane immunoreactivity was observed in the tumour islands [Table/ Fig-1a-d].…”

BRCA1 Suppresses Osteopontin-mediated Breast Cancer

“…OPN is usually absent or expressed at a low level in normal tissues but is up-regulated in certain preneoplastic and neoplastic epithelia (63)(64)(65), including that of the breast (6). Indeed, OPN overexpression has adverse prognostic significance in human breast cancer (6,7).…”

Papilloma Development Is Delayed in Osteopontin-Null Mice: Implicating an Antiapoptosis Role for Osteopontin

“…Interestingly, osteopontin-null or osteopontin-deficient mice (11,12) show no developmental abnormalities or gross bone deformities unless intervention studies are done, suggesting protein redundancy for normal development and differentiation and that overexpression of osteopontin is more important in pathologic conditions, such as tumor development. Elevated expression of osteopontin has been reported in benign (13)(14)(15) and malignant tumors from organs, such as brain, breast, mouth, salivary glands, thyroid gland, lung, stomach, endometrium, ovary, kidney, colon, prostate, liver, and pancreas (10,16,17). Furthermore, elevated levels of osteopontin were detected in serum from breast, ovary, colon, prostate, pancreas, and lung cancer patients (10,17).…”