Conclusions
Prostate cancer cell mechanotransduction increases endosomes, lysosomes, and proton pumps-where increases have been associated with enhanced cancer aggressiveness. We also show that the prostate cancer cell's response to force promotes the cancer drivers mTORC1 and mTORC2.
Methods
Moderately metastatic DU145 and highly metastatic PC3 prostate cancer cells were subjected to 0.05 dynes cm-2<math><msup><mtext>cm</mtext> <mrow><mo>-</mo> <mn>2</mn></mrow> </msup> </math> wall shear stress for 24 h, followed by immunocytochemistry and fluorescence measurements of β<math><mi>β</mi></math> 1 integrin, endosome, lysosome, V-H +<math><msup><mrow></mrow> <mo>+</mo></msup> </math> -ATPase proton pump, mTORC1, and p-mTORC2 antibodies. Post shear stress migration assays, and the effects of vacuolar proton pump inhibitor Bafilomycin A1 (60 nM, 24 h) as well as shear stress on the ICC fluorescence intensity of the proteins of interest were conducted with DU145 cells.
Results
Low fluid shear stress increases the fluorescence intensity of β<math><mi>β</mi></math> 1 integrin, endosome, lysosome, V-H +<math><msup><mrow></mrow> <mo>+</mo></msup> </math> -ATPase, mTORC1, and p-mTORC2 antibodies in PC3 and DU145 cells, and also increased cell migration. However, Bafilomycin A1 decreased fluorescence intensity of all of these proteins in DU145 cells exposed to shear stress, revealing that V-H +<math><msup><mrow></mrow> <mo>+</mo></msup> </math> -ATPase controls the expression of these proteins. Conclusions: Prostate cancer cell mechanotransduction increases endosomes, lysosomes, and proton pumps-where increases have been associated with enhanced cancer aggressiveness. We also show that the prostate cancer cell's response to force promotes the cancer drivers mTORC1 and mTORC2.