High-grade trichoblastic carcinoma arising through malignant transformation of trichoblastoma: Immunohistochemical analysis and the expression of p53 and phosphorylated AKT.

Trichoblastoma (TB) is a benign cutaneous adnexal neoplasm. The lesion typically presents as a slow-growing, solitary, well-circumscribed nodule measuring up to 3 cm in diameter. On rare occasions, TB causes malignant transformation into an aggressive form described as high-grade trichoblastic carcinoma. Four such cases have been reported to date; all were described as high-grade trichoblastic carcinomas. Here, we describe the case of a 72-year-old Japanese male patient with a rapidly enlarging subcutaneous tumor on his lower back, which was diagnosed as high-grade trichoblastic carcinoma. Histopathologically, the tumor featured both benign and malignant components, and a transition zone between these states was clearly evident. In the immunohistochemical analysis, a malignant component was positive for p53 and showed stronger staining of phospho-RAC-α serine/threonine-protein kinase (AKT) Ser473 in comparison with a benign component. These results suggest that loss of p53 function and activation of phosphatidylinositol 3-kinase-AKT signaling pathways played important pathogenic roles in malignant transformation of the present case.

Efficient synthesis of (+/-)-parasitenone, a novel inhibitor of NF-kappaB.

Dehydroxymethylepoxyquinomicin (DHMEQ, 1) is a novel nuclear factor-kappaB (NF-kappaB) inhibitor that inhibits DNA binding of NF-kappaB components including p65. To inspect its biological activity of 1, we synthesized parasitenone (3), possessing the common epoxycyclohexenone moiety of 1. Assessment of the inhibitory activity against NF-kappaB indicated that the epoxycyclohexenone moiety is the most essential element for the NF-kappaB inhibitory activity and the salicylic acid moiety may contribute the binding efficiency and specificity.