Tazarotene (Zorac) is a synthetic, topical retinoid. Tazarotene induces the expression of tazarotene-induced gene 3 (TIG3), a tumor suppressor gene. In psoriasis, tazarotene normalizes abnormal keratinocyte differentiation and reduces their hyperproliferation.

Tazarotene causes ERK activation, RB tumor suppressor protein hypophosphorylation, G0 arrest, and myeloid differentiation in HL-60 human myeloblastic leukemia cells. Tazarotene could propel either early or late portions of the period leading to differentiation and G0 arrest and is interchangeable with an RARalpha-selective ligand. [1] Tazarotene therapy regulates gene transcription via interaction with specific nuclear retinoic acid receptors (RARs), thereby modulating the three key pathogenic factors in psoriasis. [2] Tazarotene inhibits the proliferation of fibroblasts and synthesis of DNA and collagen. [3] Tazarotene down-regulates markers of keratinocyte differentiation, keratinocyte proliferation, and inflammation. Tazarotene also up-regulates three novel genes TIG-1 (tazarotene-induced gene-1), TIG-2, and TIG-3, which may mediate an antiproliferative effect. [4] Tazarotene causes growth suppression in retinoid-responsive breast cancer cell lines by up-regulating TIG3. [5]

Tazarotene treatment reduces the number and size of microscopic basal cell carcinomas (BCCs) in UV-treated Ptch1+/? mice. Tazarotene treatment reduces the number and size of microscopic basal cell carcinomas (BCCs) in ionizing radiation-treated Ptch1+/? mice. [5]