PSAT1 and osteosarcoma: To study the intracellular localization of PSAT1, we used indirect immunofluorescence to evaluate the distribution of PSAT1 in the endoplasmic reticulum (ER), nucleus and microtubules of A-431 (Human epidermal carcinoma), U-251MG (Human astroglioma cells) and U-2 osteosarcoma cells.