Alteration in keratinocyte ganglioside content in basal cell carcinomas

We examined the ganglioside content of normal human keratinocytes and basal cell carcinomas (BCC). The total ganglioside content of the epidermis was 0.098 ± 0.01 μg lipid-bound sialic acid/mg dry weight. G_M3 was the predominant ganglioside of epidermis. G_M2 and G_D3 were also found in significant amounts. Polysialylated gangliosides were identified in only small amounts. In contrast to all other body locations, breast epidermis showed large amounts of G_M1. The total ganglioside content of nodular and sclerosing facial BCC was approximately 3.5 times that of normal facial epidermis. This marked elevation of total ganglioside was not affected by dermal ganglioside contamination, because the total ganglioside content of the dermis was similar to that of the epidermis. The relative percentage of G_M2 was significantly decreased, whereas the relative percentage of G_M3 was slightly decreased in BCC. 9-O-acetyl-G_D3 was present in the BCC, but not in normal epidermis or dermis. 9-O-acetyl-G_D3 may be a surface marker for BCC. Furthermore, the alterations in amount and composition of individual gangliosides on neoplastic membranes may lead to novel therapeutic interventions.