Pharmacotherapy and Immunotherapy of Conjunctival Tumors

Transient Mitomycin C-treatment of human corneal epithelial cells and fibroblasts alters cell migration, cytokine secretion, and matrix accumulation

A single application of Mitomycin C (MMC) is used clinically in ophthalmology to reduce scarring and enhance wound resolution after surgery. Here we show in vitro that a 3-hour MMC treatment of primary and telomerase immortalized human corneal limbal epithelial (HCLE) cells impacts their migration and adhesion. Transient MMC treatment induces HCLE expression of senescence associated secretory factors, cytokine secretion, and deposition of laminin 332 for several days. Transient MMC treatment also reduces migration and deposition of transforming growth factor-β1 (TGFβ1)-stimulated collagen by corneal fibroblasts. Using conditioned media from control and MMC treated cells, we demonstrate that factors secreted by MMC-treated corneal epithelial cells attenuate collagen deposition by HCFs whereas those secreted by MMC-treated HCFs do not. These studies are the first to probe the roles played by corneal epithelial cells in reducing collagen deposition by corneal fibroblasts in response to MMC.

[Focus on clinical and pathological management of conjunctival melanocytic tumors]

Conjunctival-pigmented tumors are rare, but they are one of the most commonly encountered by the pathologist working with the department of ophthalmology. Nevus and melanoma can be encountered and have some histological difference compared to their cutaneous counterpart. Primary acquired melanosis (PAM) is a conjunctival specific entity. This clinical term includes several histological lesions ranging from benignity to melanoma precursor lesion. Histologic examination determines the therapy and the risk of progression to melanoma. We present here a histopathological, clinical and therapeutic synthesis of conjunctival-pigmented lesions, emphasizing the importance of a good understanding between clinicians and pathologists.