MTT and Cell Proliferation Assay A431Ctrl, A431SE1, and A431SE1-H38A (7500 cells/well) were seeded in a 24-well plate and incubated at 37 C with 5% CO2. suggests that CDC42SE1 modulates the CDC42-mediated Akt pathway by competing with other effector proteins to bind CDC42. A431SE1 cells formed smaller colonies in soft agar compared to A431Ctrl and A431SE1-H38A cells. These findings correlate with nude mice xenograft assays, where A431SE1 cells formed tumors with significantly-reduced volume compared to the tumors formed by A431Ctrl cells. Our results suggest that CDC42SE1 is usually downregulated in skin cancer to promote tumorigenesis, and thus CDC42SE1 might be an important marker of skin malignancy progression. for 5 min. The cell pellet was lysed with KinexTM lysate buffer (Vancouver, BC, Canada), as per the manufacturers protocol. Protein lysates (50 g) from A431SE1 and A431Ctrl cells were labeled with fluorescent dye provided in the kit. The labelled samples were loaded separately onto the antibody microarray glass slide and incubated for 2 h at room heat. The microarray slide was washed after the incubation Rabbit polyclonal to Ezrin to remove unbound protein and scanned with a Perkin-Elmer Scan Array Express Reader (Waltham, MA, USA). 2.4. MTT and Cell Proliferation Assay A431Ctrl, A431SE1, and A431SE1-H38A (7500 cells/well) were seeded in a 24-well plate and incubated at 37 C with 5% CO2. After 72 h incubation, the cells were used for the MTT assay and cell counting with hemocytometer. For MTT assay, the tetrazolium salt, 3-4,5-dimethylthiazol-2,5-diphenyl tetrazolium bromide (MTT) (5 mg/mL) was added to each well and incubated for 3.5 h at 37 C in CO2 incubator. MTT solvent (0.1% NP-40 with 4mM HCl) was added slowly into the well and kept for 15 min. The optical density was measured using a plate reader (Tecan, M?nnedorf, Switzerland) at 590 nm and 2,4-Pyridinedicarboxylic Acid at 620 nm (reference). The readings at 620 nm were subtracted from the 590 nm readings. 2.5. Cell Spreading Assay A431SE1, A431SE1-H38A, and A431Ctrl cells (30,000 cells/well) were seeded on a fibronectin coated 96-well plate and incubated at 37 C in a humidified CO2 (5%) incubator. The cells were imaged at 0 min, 10 min, and 20 min time intervals. The surface area of the cells (30 cells/well) was calculated using Image J software . 2.6. Colony Formation Assay A431SE1, A431SE1-H38A, and A431Ctrl cells (1 103 cells/well) were seeded in a 6-well plate and cultured with DMEM with 10% FBS for two weeks. Colonies were stained with 0.05% Crystal Violet for 30 min and washed 5 times with PBS. The number of colonies ( 0.1 mm) were counted manually from three impartial experiments. 2.7. Soft Agar Colony Formation Assay We 2,4-Pyridinedicarboxylic Acid coated 6-well plates with 1.0% noble agar in complete media (1.5 mL agar/well) and allowed it to solidify at room temperature for 15 min. A431SE1, A431SE1-H38A, and A431Ctrl cells (25 103/mL) were separately mixed with 0.6% noble agar and added to separate agar-coated wells and allowed to solidify for another 20 min. Complete media (500 L) was added to each well to prevent drying, and they were incubated for 14 days. Colonies were stained with 0.05% Crystal Violet for 1 h, washed with PBS, and images of the colonies were captured using an Olympus microscope (Tokyo, Japan) with 4 objective lens. The average number of colonies was calculated manually, and the average area of colonies was quantified using Image J software 2.8. Immunoblotting Cells were lysed using RIPA lysis buffer (Sigma-Aldrich, St. Louis, MO, USA) and the equivalent of 30 g of total protein was boiled with SDS-PAGE sample buffer 5 min at 100 C, proteins were resolved using Polyacrylamide (8%, 2,4-Pyridinedicarboxylic Acid 10% or 15%) SDS-PAGE gel, and transferred onto nitrocellulose membrane. The membrane was probed with primary antibodies CDC42SE1, Akt, P-Akt, mTOR, P-mTOR, 4EBP-1, P-4EBP-1, P-PTEN, PTEN, washed, incubated with.