RETRACTED: Berberine inhibits growth, induces G1arrest and apoptosis in human epidermoid carcinoma A431 cells by regulating Cdki–Cdk-cyclin cascade, disruption of mitochondrial membrane potential and cleavage of caspase 3 and PARP

Abstract

Chemotherapeutic approach using non-toxic botanicals may be one of the strategies for the management of the skin cancers. Here we report that in vitro treatment of human epidermoid carcinoma A431 cells with berberine, a naturally occurring isoquinoline alkaloid, decreased cell viability (3-77%, P < 0.05-0.001) and induced cell death (3-51%, P < 0.01-0.001) in a dose (5-75 microM)- and time (12-72 h)-dependent manner, which was associated with an increase in G(1) arrest. G(0)/G(1) phase of the cell cycle is known to be controlled by cyclin dependent kinases (Cdk), cyclin kinase inhibitors (Cdki) and cyclins. Our western blot analysis showed that berberine-induced G(1) cell cycle arrest was mediated through the increased expression of Cdki proteins (Cip1/p21 and Kip1/p27), a simultaneous decrease in Cdk2, Cdk4, Cdk6 and cyclins D1, D2 and E and enhanced binding of Cdki-Cdk. In additional studies, treatment of A431 cells with berberine (15-75 microM) for 72 h resulted in a significant dose-dependent increase in apoptosis (31-60%, P < 0.05-0.001) than non-berberine-treated control (11.7%), which was associated with an increased expression of pro-apoptotic protein Bax, decreased expression of anti-apoptotic proteins Bcl-2 and Bcl-xl, disruption of mitochondrial membrane potential, and activation of caspases 9, 3 and poly (ADP-ribose) polymerase. Pretreatment of A431 cells with the pan-caspase inhibitor (z-VAD-fmk) significantly blocked the berberine-induced apoptosis in A431 cells confirmed that berberine-induced apoptosis is mediated through activation of caspase 3-dependent pathway. Together, this study for the first time identified berberine as a chemotherapeutic agent against human epidermoid carcinoma A431 cells in vitro, further in vivo studies are required to determine whether berberine could be an effective chemotherapeutic agent for the management of non-melanoma skin cancers.

PKR , a p53 target gene, plays a crucial role in the tumor-suppressor function of p53

“…The phosphorylation of eIF2␣ at Ser-51 leads to a significant reduction in protein synthesis, concomitant with induced expression of the basic leucine zipper (bZIP) regulator, activating transcription factor 4 (ATF4), and its target gene CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP), resulting in caspase activation and cell apoptosis (27). In accordance with our recent report (28), enhancements of ATF4/CHOP, followed by caspase-mediated cleavage of poly(ADP-ribose) polymerase (PARP) (29) were detected readily in p53 ϩ/ϩ PKR ϩ/ϩ cells but were barely detectable in the p53 ϩ/ϩ PKR KD (sh-PKR) cells under conditions of DNA damage (Fig. 4G).…”

Berberine Induces Cell Cycle Arrest in Cholangiocarcinoma Cell Lines <i>via</i> Inhibition of NF-κB and STAT3 Pathways

“…Berberine seems preferentially active on CCA cell lines rather than on other cancer cell lines when comparing the IC 50 of berberine on several cancer cell lines, e.g., epidermoid carcinoma A431 cells, 19) neuroblastoma cells, 20) and prostate carcinoma cells (LNCaP, DU145 and PC-3).…”

Different concentrations of berberine result in distinct cellular localization patterns and cell cycle effects in a melanoma cell line

“…Berberine has been reported to induce apoptosis through a mitochondrial pathway that includes upregulation of p53, alterations in Bcl-2/Bax ratios, a decrease in mitochondrial membrane potential, release of cytochrome c, and activation of caspases [2,[6][7][8][9][10][11][12]. This is of particular interest in light of studies demonstrating a mitochondrial localization of berberine, raising the possibility that apoptosis results from mitochondrial damage induced by berberine.…”