Specific features of apoptosis in human lens epithelial cells induced by mitomycin C in vitro

Background: Posterior capsule opacification (PCO) is still one of the major complications following modern cataract surgery. Several attempts have been made to find an appropriate therapeutic concept to significantly lower the rate of PCO. Here, we wanted to focus on the antimetabolic strategy, reducing PCO by using mitomycin C, further characterizing the pathway of apoptosis in human lens epithelial cells (hLECs). Methods: Human lens epithelial cells were obtained from anterior lens capsules during cataract surgery. The expression of Fas, TRAMP, TRAIL-R1-R4, Apo-3L and TRAIL mRNA was investigated by means of RT PCR using specific primers. For investigations on bcl-2, bax, p53 and the active form of caspase 3, cell cultures of hLECs were pretreated with mitomycin C and processed for immunocytochemistry thereafter. Results: We detected the expression of the receptors Fas, TRAMP, TRAIL-R2 and TRAIL-R3 in hLECs. We further obtained evidence of the upregulation of the intracellular apoptotic signalling cascade, represented by bcl-2 and bax, the transcription factor p53 and the active form of caspase 3, after pretreatment with mitomycin C. Conclusion: We demonstrated the presence of the apoptosis-receptor system in hLECs. Furthermore, we demonstrated the possibility of the induction of key proteins of the apoptotic signalling cascade in these cells by the antimetabolic drug mitomycin C. This could have important implications on the strategies regarding both the prevention and the treatment of PCO after cataract surgery.