W Roy Smythe1, Imran Mohuiddin, Mustafa Ozveran, Xiaobo X Cao. 1. Department of Thoracic and Cardiovascular Surgery, Section of Thoracic Molecular Oncology, University of Texas M.D. Anderson Cancer Center, Houston, 77030, USA. rsmythe@mdanderson.org
Abstract
OBJECTIVE: Malignant pleural mesothelioma is resistant to conventional therapies and to apoptosis. The bcl-2 family genes are major determinants of apoptotic homeostasis. Malignant pleural mesothelioma lines and tumors rarely express the antiapoptotic Bcl-2 protein but routinely express the antiapoptotic protein Bcl-xl and the proapoptotic proteins Bax and Bak. We have previously shown pharmacologic inhibition of bcl-xl expression in malignant pleural mesothelioma can lead to apoptosis, so we sought to determine whether antisense oligonucleotides directed at bcl-xl messenger RNA would engender apoptosis, possibly through a "forced imbalance" of bcl-2 family proteins. METHODS: Malignant pleural mesothelioma lines REN (epithelial) and I-45 (sarcomatous) were exposed to modified bcl-xl antissense oligonecleotides directed near the messenger RNA initiation sequence with and without a liposomal delivery system. Untreated cells and bcl-xl sense oligonucleotides were controls. Cell viability was measured by colorimetric assay, and apoptosis was evaluated with Hoechst staining and sub-G(1) fluorescence-activated cell sorter analysis. RESULTS: Bcl-xl protein expression after antisense oligonucleotides was downwardly regulated in both cell lines relative to sense oligonucleotides (>65%). Significant cellular killing in both the I-45 and REN cell lines was achieved with antisense oligonucleotides (compared with sense oligonucleotides) without (P =.003 and.006, respectively) and with (P =.006 and.0005, respectively) liposomal delivery. Hoechst staining and sub-G(1) fluorescence-activated cell sorter analysis demonstrated apoptosis to be the mechanism of cellular death. Use of a liposomal delivery system increased therapeutic effect and allowed lower doses of antisense oligonucleotides. CONCLUSION: Antisense oligonucleotides directed at the bcl-xl gene product engender apoptosis in mesothelioma cell lines. The therapeutic potential of inhibiting expression of this protein in mesothelioma should be evaluated.
OBJECTIVE:Malignant pleural mesothelioma is resistant to conventional therapies and to apoptosis. The bcl-2 family genes are major determinants of apoptotic homeostasis. Malignant pleural mesothelioma lines and tumors rarely express the antiapoptotic Bcl-2 protein but routinely express the antiapoptotic protein Bcl-xl and the proapoptotic proteins Bax and Bak. We have previously shown pharmacologic inhibition of bcl-xl expression in malignant pleural mesothelioma can lead to apoptosis, so we sought to determine whether antisense oligonucleotides directed at bcl-xl messenger RNA would engender apoptosis, possibly through a "forced imbalance" of bcl-2 family proteins. METHODS:Malignant pleural mesothelioma lines REN (epithelial) and I-45 (sarcomatous) were exposed to modified bcl-xl antissense oligonecleotides directed near the messenger RNA initiation sequence with and without a liposomal delivery system. Untreated cells and bcl-xl sense oligonucleotides were controls. Cell viability was measured by colorimetric assay, and apoptosis was evaluated with Hoechst staining and sub-G(1) fluorescence-activated cell sorter analysis. RESULTS:Bcl-xl protein expression after antisense oligonucleotides was downwardly regulated in both cell lines relative to sense oligonucleotides (>65%). Significant cellular killing in both the I-45 and REN cell lines was achieved with antisense oligonucleotides (compared with sense oligonucleotides) without (P =.003 and.006, respectively) and with (P =.006 and.0005, respectively) liposomal delivery. Hoechst staining and sub-G(1) fluorescence-activated cell sorter analysis demonstrated apoptosis to be the mechanism of cellular death. Use of a liposomal delivery system increased therapeutic effect and allowed lower doses of antisense oligonucleotides. CONCLUSION: Antisense oligonucleotides directed at the bcl-xl gene product engender apoptosis in mesothelioma cell lines. The therapeutic potential of inhibiting expression of this protein in mesothelioma should be evaluated.
Authors: Xiaobo Cao; James Littlejohn; Charles Rodarte; Lidong Zhang; Benjamin Martino; Philip Rascoe; Kamran Hamid; Daniel Jupiter; W Roy Smythe Journal: Am J Pathol Date: 2009-10-15 Impact factor: 4.307
Authors: Sharyn I Katz; Lanlan Zhou; Grace Chao; Charles D Smith; Thomas Ferrara; Wenge Wang; David T Dicker; Wafik S El-Deiry Journal: Cancer Biol Ther Date: 2009-12-02 Impact factor: 4.742
Authors: Surein Arulananda; Megan O'Brien; Marco Evangelista; Tiffany J Harris; Nikita S Steinohrt; Laura J Jenkins; Marzena Walkiewicz; Robert J J O'Donoghue; Ashleigh R Poh; Bibhusal Thapa; David S Williams; Trishe Leong; John M Mariadason; Xia Li; Jonathan Cebon; Erinna F Lee; Thomas John; W D Fairlie Journal: Cell Death Discov Date: 2020-10-31