Abstract
Purpose: :
Conjunctival Melanoma (CM) is a rare tumor of the ocular surface. Even though surgical excision is the treatment of choice, recurrence rates prompted the investigation of adjuvant therapies by several centers. Alcohol, cryotherapy, radiation and local chemotherapeutic agents are some of the current available options. Considering the potential risks associated with such therapies, we continue to investigate potential therapies for the treatment of this condition.
Methods: :
Immunocytochemistry was performed on cytospins of a CM cell line (CM2005.1) using monoclonal antibodies against COX-2, c-kit, PDGFA and PDGFB. A sulforhodamine-B based proliferation assay was used to compare cell growth with a range of concentrations of Amfenac and Gleevec from 1mM to 0.001µM, separately. The invasion assay was performed with a modified Boyden chamber system consisting of a membrane with 8 µm pores pre-coated with Matrigel. 1x105 cells were seeded onto the top portion of the chamber and incubated for 24h, with 10% FBS RPMI solution as chemo-attractant in the bottom of the wells. Non-invading cells were removed from the top of the Matrigel, the membrane was stained and invading cells were counted. The Student T-test was used to test for differences and a p-value of less than 0.05 was considered statistically significant.
Results: :
The CM cell line showed immunocytochemical positivity for all molecular targets. A statistically significant reduction in proliferation rate was observed with concentrations of 1 mM of Amfenac (p<0.001) and 1mM, 100µM and 10µM of Gleevec (p<0.001). Both drugs also significantly impaired the invasive abilities of the CM cell line (p=0.014 for Amfenac and p=0.025 for Gleevec).
Conclusions: :
To the best of our knowledge, this is the first time that the effectiveness of Amfenac or Gleevec against a CM cell line was assessed in vitro. Given the high rates of recurrence after tumor excision, those two compounds are promising options as adjuvant therapies that may improve the treatment of the primary tumor. The incidence of metastasis might also be positively affected by decreasing the invasive potential of any residual cells.
Keywords: conjunctiva • melanoma • drug toxicity/drug effects