Expression of heat shock protein 27 and alpha-crystallins in human retinoblastoma after chemoreduction. Issue 4 (23rd September 2008)

• Record Type: Journal Article
• Authors: Kase, S; Parikh, J G; Rao, N A
• Is Part Of: British journal of ophthalmology. Volume 93:Issue 4(2009)
• Page Start: 541
• Page End: 544
• Publication Date: 2008-09-23
• Subjects: Ophthalmology -- Periodicals; 617.7
• DOI: 10.1136/bjo.2008.145508
• Languages: English
• ISSNs: 0007-1161

Abstract

Abstract : Aim: Small heat shock proteins (sHSP) play an important role in the resistance to anticancer drugs. We examined the expression of the sHSP family, HSP27 and α-crystallins, in human retinoblastoma with and without preoperative chemotherapy. Methods: Eighteen enucleated eyes from patients with retinoblastoma were used. Six patients had undergone chemotherapy before enucleation. Formalin-fixed, paraffin-embedded tissue sections were processed for H&E staining and examined by immunohistochemistry using anti-HSP27 and α-crystallins antibodies. Results: Eleven of 12 cases with no history of preoperative chemotherapy showed weakly positive or negative staining for HSP27, whereas six and five cases were strongly positive for αA and αB-crystallin, respectively. In the six cases with a history of chemotherapy, several viable retinoblastoma cells remained. Immunoreactivity for HSP27 and αB-crystallin was strongly detected in the cytoplasm of viable retinoblastoma cells, while αA-crystallin immunoreactivity was less marked. Immunoreactivity for HSP27 was significantly higher in retinoblastoma cases with preoperative chemotherapy than in those without chemotherapy (p<0.0001). In contrast, immunoreactivity for αA-crystallin was significantly lower in cases with chemotherapy than in cases without chemotherapy (p<0.01). Conclusions: HSP27 and αB-crystallin, but not αA-crystallin, were highly expressed in viable tumour cells after chemotherapy, suggesting that HSP27 and αB-crystallin may protect tumour cells from apoptotic signals produced by anticancer drugs in retinoblastoma.