PURPOSE: To investigate the potential role for CD44(+) and CD90(+) hepatocellular carcinoma (HCC) cellular subpopulations in biological response to thermal ablation-induced heat stress. METHODS: This study was approved by the institutional animal care committee. The N1S1 rat HCC cell line was subjected to sublethal heat stress (45 °C) or control (37 °C) for 10 min, costained with fluorescent-labeled antibodies against CD44, CD90, and 7-AAD after a 48-h recovery and analyzed by flow cytometry to assess the percentage of live CD44(+) and CD90(+) HCC cells (n = 4). Experiments were repeated with pretreatment of N1S1 cells with a dose titration of the dual PI3K-mTOR inhibitor BEZ235 or vehicle control (n = 3). Rats bearing orthotopic N1S1 tumors were subjected to ultrasound-guided partial laser ablation (n = 5) or sham ablation (n = 3), euthanized 24 h after ablation, and liver/tumor analyzed for immunohistochemical staining of CD44 and CD90. Differences between groups were compared with an unpaired t test. RESULTS: Sublethal heat stress induced a significant increase in the relative proportion of live CD44(+) and CD90(+) HCC cells compared to the control group: CD44(+)CD90(-) (5.3-fold; p = 0.0001), CD44(-)CD90(+) (2.4-fold; p = 0.003), and CD44(+)CD90(+) (22.0-fold; p < 0.03). Inhibition of PI3K-mTOR prevented heat stress-induced enrichment of the population of live CD44(+) HCC cells (p < 0.01), but not CD90(+) cells (p > 0.10). Immunohistochemical analysis demonstrated preferential localization of clusters of CD44(+) cells at both the tumor margin and ablation margin. CONCLUSION: These studies provide experimental evidence supporting a role for HCC cells expressing the putative stem cell marker CD44 in HCC response to heat stress.
PURPOSE: To investigate the potential role for CD44(+) and CD90(+) hepatocellular carcinoma (HCC) cellular subpopulations in biological response to thermal ablation-induced heat stress. METHODS: This study was approved by the institutional animal care committee. The N1S1 rat HCC cell line was subjected to sublethal heat stress (45 °C) or control (37 °C) for 10 min, costained with fluorescent-labeled antibodies against CD44, CD90, and 7-AAD after a 48-h recovery and analyzed by flow cytometry to assess the percentage of live CD44(+) and CD90(+) HCC cells (n = 4). Experiments were repeated with pretreatment of N1S1 cells with a dose titration of the dual PI3K-mTOR inhibitor BEZ235 or vehicle control (n = 3). Rats bearing orthotopic N1S1 tumors were subjected to ultrasound-guided partial laser ablation (n = 5) or sham ablation (n = 3), euthanized 24 h after ablation, and liver/tumor analyzed for immunohistochemical staining of CD44 and CD90. Differences between groups were compared with an unpaired t test. RESULTS: Sublethal heat stress induced a significant increase in the relative proportion of live CD44(+) and CD90(+) HCC cells compared to the control group: CD44(+)CD90(-) (5.3-fold; p = 0.0001), CD44(-)CD90(+) (2.4-fold; p = 0.003), and CD44(+)CD90(+) (22.0-fold; p < 0.03). Inhibition of PI3K-mTOR prevented heat stress-induced enrichment of the population of live CD44(+) HCC cells (p < 0.01), but not CD90(+) cells (p > 0.10). Immunohistochemical analysis demonstrated preferential localization of clusters of CD44(+) cells at both the tumor margin and ablation margin. CONCLUSION: These studies provide experimental evidence supporting a role for HCC cells expressing the putative stem cell marker CD44 in HCC response to heat stress.
Authors: A M Martelli; C Evangelisti; M Y Follo; G Ramazzotti; M Fini; R Giardino; L Manzoli; J A McCubrey; L Cocco Journal: Curr Med Chem Date: 2011 Impact factor: 4.530
Authors: Scott M Thompson; Danielle E Jondal; Kim A Butters; Bruce E Knudsen; Jill L Anderson; Matthew P Stokes; Xiaoying Jia; Joseph P Grande; Lewis R Roberts; Matthew R Callstrom; David A Woodrum Journal: Int J Hyperthermia Date: 2017-11-06 Impact factor: 3.914
Authors: Scott M Thompson; Matthew R Callstrom; Kim A Butters; Bruce Knudsen; Joseph P Grande; Lewis R Roberts; David A Woodrum Journal: Lasers Surg Med Date: 2014-03-18 Impact factor: 4.025
Authors: Scott M Thompson; Matthew R Callstrom; Danielle E Jondal; Kim A Butters; Bruce E Knudsen; Jill L Anderson; Karen R Lien; Shari L Sutor; Ju-Seog Lee; Snorri S Thorgeirsson; Joseph P Grande; Lewis R Roberts; David A Woodrum Journal: PLoS One Date: 2016-09-09 Impact factor: 3.240