Fig. 6. SHMT2 inhibition reduces cancer cell proliferation and survival under stress conditions.

A Cell lines were transfected with control non-targeting siRNA (siCtrl) or SHMT2-directed siRNA (siSHMT2) for 48 h. Cell proliferation was measured by direct cell counting. Mean ± SD (n = 4). *p < 0.01, **p < 0.001, ***p < 0.0001. B Prostate cancer cell lines (LNCaP, C4–2B, DU145, and PC3) were treated with increasing concentrations (0–100 μM) of SHIN1 for 48 h, Cell proliferation was measured by direct cell counting. Mean ± SD (n = 3). C, D LNCaP and DU145 cells were plated and treated with or without SHIN1 (10 or 20 μM) for colony formation assay. Colonies were analyzed by crystal violet staining after 10 days and quantified (D). Mean ± SD (n = 3). *p < 0.01, **p < 0.001. E, F DU145 cells were treated with or without SHIN1 (10 or 20 μM) for 24 h. Cells were incubated in (E) H₂O₂ (50 μM) or (F) low glucose (1 mM) for 24 h. Cell proliferation was measured by direct cell counting. Mean ± SD (n = 4). *p = 0.0210, ***p < 0.0001. G DU145 cells were transfected with control non-targeting siRNA (siCtrl) or LONP1 (siLONP1) and/or ClpP-directed siRNA (siClpP) for 48 h. Cells were incubated with SHIN1 (20 μM) for 24 h. Cell proliferation was measured by direct cell counting. Mean ± SD (n = 4). *p = 0.0032, **p < 0.001, ***p < 0.0001.