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Updated: Jun 30, 2026
Reconstruct Human Retinoblastoma In Vitro
Published on: October 11, 2022
Expression of heat shock protein 27 and alpha-crystallins in human retinoblastoma after chemoreduction
1Doheny Eye Institute, 1450 San Pablo Street, DRVC 211, Los Angeles, CA 90033, USA. nrao@usc.edu
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 alpha-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 alpha-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 alphaA and alphaB-crystallin, respectively. In the six cases with a history of chemotherapy, several viable retinoblastoma cells remained. Immunoreactivity for HSP27 and alphaB-crystallin was strongly detected in the cytoplasm of viable retinoblastoma cells, while alphaA-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 alphaA-crystallin was significantly lower in cases with chemotherapy than in cases without chemotherapy (p<0.01).
Conclusions:
HSP27 and alphaB-crystallin, but not alphaA-crystallin, were highly expressed in viable tumour cells after chemotherapy, suggesting that HSP27 and alphaB-crystallin may protect tumour cells from apoptotic signals produced by anticancer drugs in retinoblastoma.
Insights
Small heat shock proteins (sHSP) like HSP27 and alphaB-crystallin are highly expressed in retinoblastoma cells after chemotherapy. These proteins may protect tumor cells from anticancer drug-induced apoptosis.
Area of Science:
- Oncology
- Molecular Biology
- Ophthalmology
Background:
- Small heat shock proteins (sHSP) are implicated in anticancer drug resistance.
- HSP27 and alpha-crystallins are key members of the sHSP family.
Purpose of the Study:
- To investigate the expression of HSP27 and alpha-crystallins in retinoblastoma.
- To determine the role of these proteins in chemoresistance.
Main Methods:
- Immunohistochemistry was used to analyze HSP27 and alpha-crystallin expression.
- Retinoblastoma tissues from patients with and without preoperative chemotherapy were examined.
Main Results:
- HSP27 and alphaB-crystallin were highly expressed in viable retinoblastoma cells post-chemotherapy.
- HSP27 expression was significantly higher in chemotherapy-treated cases (p<0.0001).
- AlphaA-crystallin expression was significantly lower in chemotherapy-treated cases (p<0.01).
Conclusions:
- HSP27 and alphaB-crystallin are upregulated in retinoblastoma following chemotherapy.
- These proteins may confer chemoresistance by inhibiting apoptosis in tumor cells.
- AlphaA-crystallin does not appear to play a significant role in this protective mechanism.
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