Dermatopathologic effects of taxane therapy.

Background: Taxane drugs block cell-cycle progression via centrosomal impairment, induction of abnormal spindles, and suppression of spindle microtubule dynamics. Affected cells experience aberrant mitosis or mitotic slippage, which may trigger apoptosis.

Objective: The aim was to characterize the histopathologic changes due to taxane therapy in skin biopsy specimens.

Pigmentation PAX-ways: the role of Pax3 in melanogenesis, melanocyte stem cell maintenance, and disease.

Transcription factors initiate programs of gene expression and are catalysts in downstream molecular cascades that modulate a variety of cellular processes. Pax3 is a transcription factor that is important in the melanocyte and influences melanocytic proliferation, resistance to apoptosis, migration, lineage specificity and differentiation. In this review, we focus on Pax3 and the molecular pathways that Pax3 is a part of during melanogenesis and in the melanocyte stem cell.

PAX3 expression in primary melanomas and nevi.

Melanoma is responsible for an estimated 62,000 new American cancer diagnoses and is projected to cause nearly 8000 deaths in 2008 alone. Although the histogenesis of the tumor is not well understood, it is thought to originate from a rare melanocyte stem cell that resides in the skin. The transcription factor PAX3 has a well-established role in the development of melanocytes during embryogenesis, and has recently been characterized as a molecular switch in the mature melanocyte.

PAX genes: roles in development, pathophysiology, and cancer.

PAX proteins function as transcription factors and play an essential role in organogenesis during embryonic development in regulating cell proliferation and self-renewal, resistance to apoptosis, migration of embryonic precursor cells, and the coordination of specific differentiation programs. Recent studies have also discovered a role for PAX proteins in specific stem cell or progenitor cell populations, including melanocytes, muscle, and B-cells. The normal functions of the PAX proteins, including apoptosis resistance and repression of terminal differentiation, may be subverted during the progression of a number of specific malignancies.