Fig 1: C28 impairs the viability of various human cancer cell lines.(A) Left: Viability of nontransformed and BC cell lines treated with increasing concentrations of C28 for 72 hours. The IC50 values are means from three independent experiments. Right: Western blots of LMTK3 in nontransformed and BC cell lines. (B) One-dose screening of C28 (10 µM; 24 hours) on the NCI-60 panel of tumor cell lines. The percent growth of C28-treated cells is shown. Negative values represent lethality. NSCLC, non-small cell lung cancer. (C) Western blots of BCL-XL, BCL2 and cleaved poly(ADP-ribose) polymerase (PARP) in BC cell lines following siRNA silencing of LMTK3 for 72 hours. GADPH was used as a loading control. (D) MCF7, T47D, MDA-MB-231, and MCF12A cell lines were treated with increasing concentrations of C28 for 72 hours, and the percentages of apoptotic and dead cells were analyzed by annexin V and 7-AAD staining. Results are expressed as means ± SEM; *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001. Each experiment was conducted at least three times. (E) Western blots of LMTK3, BCL2, and BCL-XL and cleaved PARP in MCF7, T47D, MDA-MB-231, and MCF12A cell lines treated with increasing concentrations of C28 for 72 hours. GADPH was used as a loading control. (F) Western blots of BCL2 and cleaved PARP levels in T47D and MDA-MB-231 cell lines treated with 10 µM C28 for 72 hours followed by LMTK3 overexpression for 48 hours. Tubulin was used as a loading control. Mean densitometry values of three independent experiments are shown. (G) T47D and MDA-MB-231 cell lines were treated with 10 µM C28 for 72 hours, followed by LMTK3 overexpression for 48 hours, and the percentages of apoptotic and dead cells were analyzed by annexin V and 7-AAD staining. Results are expressed as means ± SEM. Each experiment was conducted at least two times.