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Ionizing radiation enhances the therapeutic potential of TRAIL in prostate cancer in vitro and in vivo: Intracellular mechanisms.
Prostate. 2004 Sep 15; 61(1):35-49.P

Abstract

BACKGROUND

We assessed the influence of sequential treatment of ionizing radiation followed by tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) on intracellular mechanisms of apoptosis of prostate tumor cells in vitro and in vivo.

METHODS

Prostate normal and cancer cells were exposed to irradiation and TRAIL. Four- to 6-week-old athymic nude mice were injected s.c. with PC-3 tumor cells. Tumor bearing mice were exposed to irradiation and TRAIL, either alone or in combination (TRAIL after 24 hr of irradiation), and tumor growth, apoptosis, and survival of mice were examined. Expressions of death receptors, Bcl-2 family members, and caspase were measured by Western blotting, ELISA, and ribonuclease protection assay; tumor cellularity was assessed by H&E staining; inhibition of p53 was performed by RNA interference (RNAi) technology, and apoptosis was measured by annexin V/propidium iodide staining, and terminal deoxynucleotidyltransferase-mediated nick end labeling assay.

RESULTS

Irradiation significantly augmented TRAIL-induced apoptosis in prostate cancer cells through upregulation of DR5, Bax, and Bak, and induction of caspase activation. Dominant negative FADD and p53 siRNA inhibited the synergistic interaction between irradiation and TRAIL. The pretreatment of cells with irradiation followed by TRAIL significantly enhanced more apoptosis than single agent alone or concurrent treatment. Furthermore, irradiation sensitized TRAIL-resistant LNCaP cells to undergo apoptosis. The sequential treatment of xenografted mice with irradiation followed by TRAIL-induced apoptosis through activation of caspase-3, induction of Bax and Bak, and inhibition of Bcl-2, and completely eradicated the established tumors with enhanced survival of nude mice.

CONCLUSION

The sequential treatment with irradiation followed by TRAIL can be used as a viable option to enhance the therapeutic potential of TRAIL in prostate cancer.

Authors+Show Affiliations

Department of Pharmaceutical Sciences, University of Maryland, 20 N. Pine Street, Baltimore, MD 2120-1180, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

15287092

Citation

Shankar, Sharmila, et al. "Ionizing Radiation Enhances the Therapeutic Potential of TRAIL in Prostate Cancer in Vitro and in Vivo: Intracellular Mechanisms." The Prostate, vol. 61, no. 1, 2004, pp. 35-49.
Shankar S, Singh TR, Srivastava RK. Ionizing radiation enhances the therapeutic potential of TRAIL in prostate cancer in vitro and in vivo: Intracellular mechanisms. Prostate. 2004;61(1):35-49.
Shankar, S., Singh, T. R., & Srivastava, R. K. (2004). Ionizing radiation enhances the therapeutic potential of TRAIL in prostate cancer in vitro and in vivo: Intracellular mechanisms. The Prostate, 61(1), 35-49.
Shankar S, Singh TR, Srivastava RK. Ionizing Radiation Enhances the Therapeutic Potential of TRAIL in Prostate Cancer in Vitro and in Vivo: Intracellular Mechanisms. Prostate. 2004 Sep 15;61(1):35-49. PubMed PMID: 15287092.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Ionizing radiation enhances the therapeutic potential of TRAIL in prostate cancer in vitro and in vivo: Intracellular mechanisms. AU - Shankar,Sharmila, AU - Singh,Thiyam Ramsing, AU - Srivastava,Rakesh K, PY - 2004/8/3/pubmed PY - 2004/9/10/medline PY - 2004/8/3/entrez SP - 35 EP - 49 JF - The Prostate JO - Prostate VL - 61 IS - 1 N2 - BACKGROUND: We assessed the influence of sequential treatment of ionizing radiation followed by tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) on intracellular mechanisms of apoptosis of prostate tumor cells in vitro and in vivo. METHODS: Prostate normal and cancer cells were exposed to irradiation and TRAIL. Four- to 6-week-old athymic nude mice were injected s.c. with PC-3 tumor cells. Tumor bearing mice were exposed to irradiation and TRAIL, either alone or in combination (TRAIL after 24 hr of irradiation), and tumor growth, apoptosis, and survival of mice were examined. Expressions of death receptors, Bcl-2 family members, and caspase were measured by Western blotting, ELISA, and ribonuclease protection assay; tumor cellularity was assessed by H&E staining; inhibition of p53 was performed by RNA interference (RNAi) technology, and apoptosis was measured by annexin V/propidium iodide staining, and terminal deoxynucleotidyltransferase-mediated nick end labeling assay. RESULTS: Irradiation significantly augmented TRAIL-induced apoptosis in prostate cancer cells through upregulation of DR5, Bax, and Bak, and induction of caspase activation. Dominant negative FADD and p53 siRNA inhibited the synergistic interaction between irradiation and TRAIL. The pretreatment of cells with irradiation followed by TRAIL significantly enhanced more apoptosis than single agent alone or concurrent treatment. Furthermore, irradiation sensitized TRAIL-resistant LNCaP cells to undergo apoptosis. The sequential treatment of xenografted mice with irradiation followed by TRAIL-induced apoptosis through activation of caspase-3, induction of Bax and Bak, and inhibition of Bcl-2, and completely eradicated the established tumors with enhanced survival of nude mice. CONCLUSION: The sequential treatment with irradiation followed by TRAIL can be used as a viable option to enhance the therapeutic potential of TRAIL in prostate cancer. SN - 0270-4137 UR - https://www.unboundmedicine.com/medline/citation/15287092/Ionizing_radiation_enhances_the_therapeutic_potential_of_TRAIL_in_prostate_cancer_in_vitro_and_in_vivo:_Intracellular_mechanisms_ L2 - https://doi.org/10.1002/pros.20069 DB - PRIME DP - Unbound Medicine ER -