TY - JOUR
T1 - Advanced retinoblastoma treatment
T2 - Targeting hypoxia by inhibition of the mammalian target of rapamycin (mTOR) in LHBETATAG retinal tumors
AU - Piña, Y.
AU - Decatur, C.
AU - Murray, T. G.
AU - Houston, S. K.
AU - Gologorsky, D.
AU - Cavalcante, M.
AU - Cavalcante, L.
AU - Hernandez, E.
AU - Celdran, M.
AU - Feuer, W.
AU - Lampidis, T.
PY - 2011
Y1 - 2011
N2 - Purpose: The purpose of this study is to analyze the dose response of the mammalian target of rapamycin (mTOR) inhibitor, rapamycin, on tumor burden and hypoxia, and study the treatment effect on vasculature in LHBETATAG retinal tumors. Methods: This study was approved by the Institutional Animal Care and Use Committee and follows Association for Research in Vision and Ophthalmology guidelines. Eighteen-week-old LHBETATAG retinal tumor eyes (n = 30) were evaluated. Mice were divided into five groups and received periocular injections once weekly for two consecutive weeks of: a) 80% DMSO (dimethyl sulfoxide, vehicle control), b) 0.00333 mg/kg, c) 0.167 mg/kg, d) 3.33 mg/kg, and e) 6.67 mg/kg of rapamycin. Tumor sections were analyzed for hypoxia, tumor burden, and vasculature with immunohistochemistry techniques. Results: Reduction in tumor burden and hypoxia was significantly different between rapamycin doses and control (P < 0.002). Eyes treated with rapamycin at 0.167, 3.33, and 6.67 mg/kg showed a significant decrease in tumor burden in comparison with the vehicle control group (P = 0.019, P = 0.001, P = 0.009, respectively) and the 0.00333 mg/kg dose response (P = 0.023, P = 0.001, P = 0.010, respectively). Eyes treated with rapamycin at 3.33 mg/kg showed a significant reduction in the amount of hypoxia in comparison with the lower concentration groups (0.00333 and 0.167 mg/kg) of rapamycin (P = 0.024 and P = 0.052, respectively). The number of mature vessels was significantly lower in the 3.33 mg/kg treated versus vehicle control (P = 0.015; equal variances assumed, t-test for equality of means). The number of neovessels was not significantly different between both groups (P = 0.092). Conclusion: Inhibition of mTOR was shown to reduce tumor burden, hypoxia, and vasculature in the LHBETATAG retinoblastoma tumor model. Rapamycin may have a role in combination with chemotherapy or other adjuvant therapies to enhance retinoblastoma tumor control.
AB - Purpose: The purpose of this study is to analyze the dose response of the mammalian target of rapamycin (mTOR) inhibitor, rapamycin, on tumor burden and hypoxia, and study the treatment effect on vasculature in LHBETATAG retinal tumors. Methods: This study was approved by the Institutional Animal Care and Use Committee and follows Association for Research in Vision and Ophthalmology guidelines. Eighteen-week-old LHBETATAG retinal tumor eyes (n = 30) were evaluated. Mice were divided into five groups and received periocular injections once weekly for two consecutive weeks of: a) 80% DMSO (dimethyl sulfoxide, vehicle control), b) 0.00333 mg/kg, c) 0.167 mg/kg, d) 3.33 mg/kg, and e) 6.67 mg/kg of rapamycin. Tumor sections were analyzed for hypoxia, tumor burden, and vasculature with immunohistochemistry techniques. Results: Reduction in tumor burden and hypoxia was significantly different between rapamycin doses and control (P < 0.002). Eyes treated with rapamycin at 0.167, 3.33, and 6.67 mg/kg showed a significant decrease in tumor burden in comparison with the vehicle control group (P = 0.019, P = 0.001, P = 0.009, respectively) and the 0.00333 mg/kg dose response (P = 0.023, P = 0.001, P = 0.010, respectively). Eyes treated with rapamycin at 3.33 mg/kg showed a significant reduction in the amount of hypoxia in comparison with the lower concentration groups (0.00333 and 0.167 mg/kg) of rapamycin (P = 0.024 and P = 0.052, respectively). The number of mature vessels was significantly lower in the 3.33 mg/kg treated versus vehicle control (P = 0.015; equal variances assumed, t-test for equality of means). The number of neovessels was not significantly different between both groups (P = 0.092). Conclusion: Inhibition of mTOR was shown to reduce tumor burden, hypoxia, and vasculature in the LHBETATAG retinoblastoma tumor model. Rapamycin may have a role in combination with chemotherapy or other adjuvant therapies to enhance retinoblastoma tumor control.
KW - Anaerobic glycolysis
KW - Hypoxia
KW - MTOR
KW - Rapamycin
KW - Retinoblastoma
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UR - http://www.scopus.com/inward/citedby.url?scp=79952838967&partnerID=8YFLogxK
U2 - 10.2147/OPTH.S16172
DO - 10.2147/OPTH.S16172
M3 - Article
C2 - 21468343
AN - SCOPUS:79952838967
VL - 5
SP - 337
EP - 343
JO - Clinical Ophthalmology
JF - Clinical Ophthalmology
SN - 1177-5467
IS - 1
ER -