Alteration of integrin expression in oral squamous cell carcinomas

Abstract

OBJECTIVE: This study examines the intensity of expression of β1, α2, α3, α5, α6 integrin subunits in oral squamous cell carcinoma (SCC) as opposed to normal oral epithelium, and the intensity of expression and distribution pattern of the above subunits in relation to tumour differentiation grade. MATERIALS AND METHODS: Cryostat sections of 25 cases of oral SCC and 15 cases of normal oral epithelium were studied by immunohistochemistry (APAAP method). RESULTS: The intensity of expression of β1, α2 (Pearson χ2P < 0.001) and α6 (Test for Trend P < 0.05) integrin subunits was reduced significantly in SCC compared to normal oral epithelium. All integrin subunits were mainly expressed in the peripheral cell layer of tumour islandS. No correlation was found between the intensity of integrin expression and the degree of differentiation in SCC. The same applied to the distribution pattern of the integrin subunitS. By means of cross examination of all integrins, the loss of intensity of α2β1 integrin expression was found to have the strongest correlation with oral SCC (Ordered Logistic Regression). CONCLUSIONS: Reduced intensity of expression of all subunits was found in oral SCC compared to normal epithelium. Further investigation is needed to determine whether α2β1 integrin expression can be used as a prognostic evaluator for the behaviour of the disease.

Histological analysis of epithelial stem cells during induced pluripotent stem cell-derived teratoma development

“…At day 21, expression was clearly detected in the basal layer of the stratified epithelium (Fig. 6K), which is consistent with the expression pattern in normal mucosa [20]. On the other hand, CD49f was detected at cell surfaces not associated with the basement membrane, including the luminal surfaces of pseudostratified ciliated epithelium, simple epithelium and stratified epithelium in iPS cellderived teratomas, suggesting that CD49f has other roles independent of laminins (Fig.…”

“…It is expressed on the surface of basal keratinocytes [20], and high expression of CD49f is thought to be a marker of epithelial stem cells in mouse keratinocyte populations [34]. Moreover, CD49f expression is reduced significantly in oral squamous cell carcinoma [20]. In this study, CD49f was intensely expressed at the cell membrane in all types of epithelium observed in day-7 teratomas ( Fig.…”

“…In embryonic tissues, CD49f is required for epithelial morphogenesis [33]. It is expressed on the surface of basal keratinocytes [20], and high expression of CD49f is thought to be a marker of epithelial stem cells in mouse keratinocyte populations [34]. Moreover, CD49f expression is reduced significantly in oral squamous cell carcinoma [20].…”

“…CD49f, an integrin a 6 subunit (laminin ligand), is expressed on the surface of basal keratinocytes including the oral mucosa [20], Table 1 The time course of germ layer differentiation in iPS cell-derived teratomas (þ ; detectable, À ; undetectable). plays a crucial role in hemidesmosome assembly by binding to laminin-5 in the basement membrane [21].…”

Immunohistochemical study of oral epithelial sheets cultured on amniotic membrane for oral mucosal reconstruction

“…Integrin alpha 6 and laminin alpha 5 chain are basement membrane com- ponents [7,8], and integrin alpha 6 is a specific component of hemidesmosomes [11]. Our findings indicated that the basal epithelial cells might adhere with hemidesmosomal attachments and generate the basement membrane.…”