AICAR inhibits proliferation and induced S-phase arrest, and promotes apoptosis in CaSki cells

Abstract

Aim: The aim of the present study was to determine the effect of 5‐aminoimidazole‐4‐carboxamide‐ribonucleoside (AICAR) on proliferation, cell cycle, and apoptosis in the human epithelial cervical cancer cell line CaSki cells. Methods: Cell count and 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay were used to determine cell proliferation and viability. Hoechst 33258 staining was conducted to distinguish the apoptotic cells. Cell cycle and Annexin‐V/propidium iodide staining were analyzed by fluorescence‐activated cell sorting (FACS). A Western blot assay was used to evaluate the expression of AKT (also known as protein kinase B), mammalian target of rapamycin (mTOR), p53, and extracellular signal‐regulated kinase (ERK). Results: AICAR (500 μmol/L) significantly inhibited the proliferation of CaSki cells treated for 24, 48, and 72 h as determined by cell count. The cells at the G1 and G2 phases were dramatically decreased while cells at the S phase were increased in response to AICAR treatment for 24, 48, and 72 h. The MTT assay showed less viable cells and Hoechst fluorescent staining showed more apoptotic cells upon AICAR stimulation. The results of the Annexin‐V staining demonstrated a time‐dependent increase of apoptosis in cells treated with AICAR for 24, 36, and 48 h. Furthermore, AICAR activated caspase‐3 in a time‐dependent manner. It was also found that AICAR inhibited the phosphory‐lation of AKT and mTOR, which are important kinases regulating cell growth and survival. AICAR stimulation obviously increased the expression of the tumor suppressor p53 and the phosphorylation of ERK. Conclusion: AICAR inhibited proliferation and induced S phase arrest and promoted apoptosis in CaSki cells, which might be mediated by the downregulation of the AKT/mTOR pathway and the upregulation of the p53/ERK pathway.

The influence of the BRAF V600E mutation in thyroid cancer cell lines on the anticancer effects of 5-aminoimidazole-4-carboxamide-ribonucleoside

“…In other cancer cells (e.g. CaSki cells), AICAR significantly decreases G1 and G2 phase populations, but the proportion of cells in S-phase rises (Guan et al 2007). In line with the findings of the cited report, we found that AICAR treatment increased the S-phase population in BRAF-mutant thyroid cancer cells, compared with wild-type cells, after 48 h of incubation with AICAR (Fig.…”

“…AMPK regulates metabolic processes, including fatty acid synthesis, glucose uptake, and biogenesis of glucose transporter 4 (Bergeron et al 1999, Winder 2001, Ojuka 2004. AMPK activation has been implicated in regulation of cell proliferation and cell cycle progression and AMPK is considered to be potential target in cancer therapy (Luo et al 2005, Guan et al 2007, Fogarty & Hardie 2010. 5-Aminoimidazole-4-carboxamide-ribonucleoside (AICAR), a cell-permeable nucleoside used as an AMPK activator, has pro-apoptotic effects in cancer cell lines (Meisse et al 2002, Kefas et al 2003, Dagon et al 2006).…”

Carnosol, a Dietary Diterpene, Displays Growth Inhibitory Effects in Human Prostate Cancer PC3 Cells Leading to G2-Phase Cell Cycle Arrest and Targets the 5′-AMP-Activated Protein Kinase (AMPK) Pathway

“…(16) Agents such as the AMP-mimetic 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) have been shown to activate AMPK by energy starvation leading to phosphorylation of TSC2 at Thr-1277 and Ser-1345. (13,17) Phosphorylation at these sites increases the activity of the TSC1-TSC2 complex to inhibit mTOR. (12,18).…”

New synthetic AICAR derivatives with enhanced AMPK and ACC activation

“…AICAR plays a central role in the metabolism and in signal transduction increasing insulin properties, up-regulating mitochondrial enzymes in muscles and decreasing intra-abdominal fat [2][3][4] . It can act as an agonist and antagonist for a number of enzymes crucial for the cell life; among these, AMPKa has a fundamental role in energy homeostasis, being an energy sensor implicated in various 24,25 . Interestingly, in terms of cell proliferation, we have tested ERK1/2 phosphorylation: according to the MTT results, at 2 h of incubation, ERK1/2 phosphorylation was down regulated in treated cells (data not shown).…”