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Title: The vitamin-like dietary supplement para-aminobenzoic acid enhances the antitumor activity of ionizing radiation

Abstract

Purpose: To determine whether para-aminobenzoic acid (PABA) alters the sensitivity of tumor cells to ionizing radiation in vitro and in vivo. Methods and Materials: Cellular proliferation was assessed by WST-1 assays. The effects of PABA and radiation on tumor growth were examined with chick embryo and murine models. Real-time reverse transcriptase-polymerase chain reaction and Western blotting were used to quantify p21{sup CIP1} and CDC25A levels. Results: Para-aminobenzoic acid enhanced (by 50%) the growth inhibitory activity of radiation on B16F10 cells, whereas it had no effect on melanocytes. Para-aminobenzoic acid enhanced (50-80%) the antitumor activity of radiation on B16F10 and 4T1 tumors in vivo. The combination of PABA and radiation therapy increased tumor apoptosis. Treatment of tumor cells with PABA increased expression of CDC25A and decreased levels of p21{sup CIP1}. Conclusions: Our findings suggest that PABA might represent a compound capable of enhancing the antitumor activity of ionizing radiation by a mechanism involving altered expression of proteins known to regulate cell cycle arrest.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2]
  1. Departments of Radiation Oncology and Cell Biology, NYU Cancer Institute, New York University School of Medicine, New York, NY (United States)
  2. Departments of Radiation Oncology and Cell Biology, NYU Cancer Institute, New York University School of Medicine, New York, NY (United States). E-mail: peter.brooks@med.nyu.edu
Publication Date:
OSTI Identifier:
20793513
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 65; Journal Issue: 2; Other Information: DOI: 10.1016/j.ijrobp.2006.01.010; PII: S0360-3016(06)00108-8; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; APOPTOSIS; CELL CYCLE; CELL PROLIFERATION; EMBRYOS; GROWTH; IN VITRO; IN VIVO; MELANIN; NEOPLASMS; PABA; POLYMERASE CHAIN REACTION; PROTEINS; RADIOTHERAPY; SENSITIVITY; TUMOR CELLS; VITAMINS

Citation Formats

Xavier, Sandhya, MacDonald, Shannon, Roth, Jennifer, Caunt, Maresa, Akalu, Abebe, Morais, Danielle, Buckley, Michael T., Liebes, Leonard, Formenti, Silvia C., and Brooks, Peter C. The vitamin-like dietary supplement para-aminobenzoic acid enhances the antitumor activity of ionizing radiation. United States: N. p., 2006. Web. doi:10.1016/J.IJROBP.2006.0.
Xavier, Sandhya, MacDonald, Shannon, Roth, Jennifer, Caunt, Maresa, Akalu, Abebe, Morais, Danielle, Buckley, Michael T., Liebes, Leonard, Formenti, Silvia C., & Brooks, Peter C. The vitamin-like dietary supplement para-aminobenzoic acid enhances the antitumor activity of ionizing radiation. United States. doi:10.1016/J.IJROBP.2006.0.
Xavier, Sandhya, MacDonald, Shannon, Roth, Jennifer, Caunt, Maresa, Akalu, Abebe, Morais, Danielle, Buckley, Michael T., Liebes, Leonard, Formenti, Silvia C., and Brooks, Peter C. Thu . "The vitamin-like dietary supplement para-aminobenzoic acid enhances the antitumor activity of ionizing radiation". United States. doi:10.1016/J.IJROBP.2006.0.
@article{osti_20793513,
title = {The vitamin-like dietary supplement para-aminobenzoic acid enhances the antitumor activity of ionizing radiation},
author = {Xavier, Sandhya and MacDonald, Shannon and Roth, Jennifer and Caunt, Maresa and Akalu, Abebe and Morais, Danielle and Buckley, Michael T. and Liebes, Leonard and Formenti, Silvia C. and Brooks, Peter C.},
abstractNote = {Purpose: To determine whether para-aminobenzoic acid (PABA) alters the sensitivity of tumor cells to ionizing radiation in vitro and in vivo. Methods and Materials: Cellular proliferation was assessed by WST-1 assays. The effects of PABA and radiation on tumor growth were examined with chick embryo and murine models. Real-time reverse transcriptase-polymerase chain reaction and Western blotting were used to quantify p21{sup CIP1} and CDC25A levels. Results: Para-aminobenzoic acid enhanced (by 50%) the growth inhibitory activity of radiation on B16F10 cells, whereas it had no effect on melanocytes. Para-aminobenzoic acid enhanced (50-80%) the antitumor activity of radiation on B16F10 and 4T1 tumors in vivo. The combination of PABA and radiation therapy increased tumor apoptosis. Treatment of tumor cells with PABA increased expression of CDC25A and decreased levels of p21{sup CIP1}. Conclusions: Our findings suggest that PABA might represent a compound capable of enhancing the antitumor activity of ionizing radiation by a mechanism involving altered expression of proteins known to regulate cell cycle arrest.},
doi = {10.1016/J.IJROBP.2006.0},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 2,
volume = 65,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2006},
month = {Thu Jun 01 00:00:00 EDT 2006}
}
  • The wavelengths of sunlight considered to be responsible for erythema and skin cancer formation are in the range 290-340 nm. Formulated sunscreens usually contain an agent that absorbs in this wavelength region, and one of the most widely used is para-aminobenzoic acid (PABA). Previous work has demonstrated the sensitization by PABA of the lethal and mutagenic effects of near-ultraviolet (UV) radiation in a model bacterial system. Experiments with the mouse lymphoma L5178Y cell line have now demonstrated sensitization by PABA of the lethal effect of near-UV radiation, the extent of which, after correction for absorption of UV radiation by PABA,more » bears a direct relationship to PABA concentration. The limitations of these results in predicting the response of human skin to the presence of PABA during exposure to UV radiation is emphasized.« less
  • Purpose: To identify the role of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) during {gamma}-ionizing radiation ({gamma}-IR) treatment for non-small-cell lung cancer cells. Methods and Materials: Wild-type PTEN or mutant forms of PTEN plasmids were transfected to construct stable transfectants of the NCI-H1299 non-small-cell lung cancer cell line. Combined effects of PTEN expression and IR treatment were tested using immunoblot, clonogenic, and cell-counting assays. Related signaling pathways were studied with immunoblot and kinase assays. Results: At steady state, stable transfectants showed almost the same proliferation rate but had different AKT phosphorylation patterns. When treated with {gamma}-IR, wild-type PTENmore » transfectants showed higher levels of cell death compared with mock vector or mutant transfectants, and showed increased G{sub 2}/M cell-cycle arrest accompanied by p21 induction and CDK1 inactivation. NCI-H1299 cells were treated with phosphosinositide-3 kinase (PI3K)/AKT pathway inhibitor (LY29002), resulting in reduced AKT phosphorylation levels. Treatment of NCI-H1299 cells with LY29002 and {gamma}-IR resulted in increased cell-cycle arrest and p21 induction. Endogenous wild-type PTEN-containing NCI-H460 cells were treated with PTEN-specific siRNA and then irradiated with {gamma}-IR: however reduced PTEN levels did not induce cell-cycle arrest or p21 expression. Conclusions: Taken together, these findings indicate that PTEN may modulate cell death or the cell cycle via AKT inactivation by PTEN and {gamma}-IR treatment. We also propose that a PTEN-PI3K/AKT-p21-CDK1 pathway could regulate cell death and the cell cycle by {gamma}-IR treatment.« less
  • Fry of common carp (Cyprinus carpio) were chronically exposed to 2.5 mg Cd/L alone and in combination with 1.0 mg KMnO{sub 4}/L or 2.0 mg CoCl{sub 2}/L or a dietary supplement of vitamin B complex at the rate of 26.5 mg/100 g food. Cadmium induced edema of primary and secondary gill lamellae, nuclear swelling, and necrosis and hypertrophy of epithelial cells of the secondary gill lamellae. Similar or more severe lamellar damages were observed with exposure to cadmium together with potassium permanganate and to cadmium together with cobalt chloride. Potassium permanganate alone was also found to produce severe edema ofmore » the gill lamellae. A dietary supplement of vitamin B complex reduced the cadmium-induced gill damages and resulted in a normal gill in exposed fish. 24 refs., 4 figs., 1 tab.« less