Transfection of annexin 1 in monocytic cells produces a high degree of spontaneous and stimulated apoptosis associated with caspase‐3 activation

Abstract

1 Transfection of the pre-monomyelocytic U937 cell line with a plasmid coding for full-length annexin 1 (ANX1, 347 amino acid) leads to cell death by promoting apoptosis. In addition, overexpression of the N-terminal and the ®rst domain of the protein (144 amino acids, clone ANX1-S), which does not contain the Ca 2+ binding sites, gives susceptibility to cell apoptosis following activation by either 5 ng ml 71 tumour necrosis factor (TNF)-a or 1 ± 40 mg ml 71 etoposide. This was demonstrated by using the¯uorescent labelled annexin V, cell cycle and nuclear staining analyses. 2 Transfection with an empty plasmid (clone CMV) or with a plasmid carrying the cDNA antisense for ANX1 (clone ANX1-AS) did not alter U937 cells to the degree of apoptosis promoted by either stimulant. 3 Treatment of CMV U937 cells with TNF-a increased ANX1 mRNA and protein expression in a time-dependent manner, with maximal increases at 3 and 6 h, respectively. 4 Clone ANX1-S showed higher constitutive (more than 2 fold) and activated caspase-3 activity, associated with higher phospholipase A 2 (PLA 2 ) activity (in the region of +50 ± 100%), whereas expression of cytosolic PLA 2 Bax and Bcl-2 were similar in all cell clones, as determined by Western blotting. 5 In conclusion, this study demonstrates a complex regulatory role of cell apoptosis for ANX1, at least with regards to cells of the myelo-monocytic lineage.

MicroRNA-196a targets annexin A1: a microRNA-mediated mechanism of annexin A1 downregulation in cancers

“…Recent studies have also shown that miRNA-196a levels are inversely correlated with survival in pancreatic adenocarcinoma patients (Bloomston et al, 2007). ANXA1 is known to be a mediator of apoptosis and suppressor of cell proliferation (Solito et al, 2001). By targeting and suppressing ANXA1 levels, miR-196a may promote deregulated growth characteristics in cells.…”

“…Furthermore, ANXA1 overexpression promoted caspase-mediated apoptosis in bronchoalveolar cells (Debret et al, 2003) and macrophages (Solito et al, 2001) and facilitated H 2 O 2 -induced apoptosis in thymocytes (Sakamoto et al, 1996). In prostate cancer cell lines, ANXA1 overexpression resulted in reduced cell viability and colony formation, enhanced apoptosis and suppressed response to epidermal growth factor signaling (Hsiang et al, 2006).…”

“…Cloned as a phospholipase A2 inhibitor (Wallner et al, 1986), ANXA1 was identified as a critical mediator of apoptosis (Solito et al, 2001) and subsequently implicated in the actions of glucocorticoids, including the inhibition of cell proliferation and regulation of cell migration (Parente and Solito, 2004). In addition, ANXA1 is also shown to be involved in varied biological functions including membrane trafficking, exocytosis, signal transduction, cell differentiation and apoptosis (Gerke and Moss, 2002).…”

Differential antiproliferative mechanisms of novel derivative of benzimidazo[1,2-α]quinoline in colon cancer cells depending on their p53 status

“…Our proteomic analysis revealed an elevated expression of this protein in treated HCT 116 cells as well. Several lines of evidence indicate that an overexpression of Annexin I induces caspase-3-mediated apoptosis in monocytic (24), bronchoalveolar (25), and prostate cancer cells (26), which again brings attention to the role of caspase-3-dependent apoptotic pathway in HCT 116. However, we cannot rule out the possibility that other apoptosis pathways are also provoked in this cell line, as we found activation of the AIF protein in treated cells, which provides direct evidence for induction of caspase-independent cell death process.…”

Proteomic identification of p53-dependent protein phosphorylation

“…Overexpression of ANXA1 promotes apoptosis associated with caspase-3 activation (Solito et al, 2001). ANXA1 was identified as an 'eat-me' signal on apoptotic cells that are recognized and ingested by phagocytes (Arur et al, 2003).…”