Dual modulation of Ras-Mnk and PI3K-AKT-mTOR pathways: A Novel c-FLIP inhibitory mechanism of 3-AWA mediated translational attenuation through dephosphorylation of eIF4E.

The eukaryotic translation initiation factor 4E (eIF4E) is considered as a key survival protein involved in cell cycle progression, transformation and apoptosis resistance. Herein, we demonstrate that medicinal plant derivative 3-AWA (from Withaferin A) suppressed the proliferation and metastasis of CaP cells through abrogation of eIF4E activation and expression via c-FLIP dependent mechanism. This translational attenuation prevents the de novo synthesis of major players of metastatic cascades viz. c-FLIP, c-Myc and cyclin D1. Moreover, the suppression of c-FLIP due to inhibition of translation initiation complex by 3-AWA enhanced FAS trafficking, BID and caspase 8 cleavage. Further ectopically restored c-Myc and GFP-HRas mediated activation of eIF4E was reduced by 3-AWA in transformed NIH3T3 cells. Detailed underlying mechanisms revealed that 3-AWA inhibited Ras-Mnk and PI3-AKT-mTOR, two major pathways through which eIF4E converges upon eIF4F hub. In addition to in vitro studies, we confirmed that 3-AWA efficiently suppressed tumor growth and metastasis in different mouse models. Given that 3-AWA inhibits c-FLIP through abrogation of translation initiation by co-targeting mTOR and Mnk-eIF4E, it (3-AWA) can be exploited as a lead pharmacophore for promising anti-cancer therapeutic development.

Par-4 dependent modulation of cellular ß-catenin by medicinal plant natural product derivative 3-azido Withaferin A.

Here, we provide evidences that natural product derivative 3-azido Withaferin A (3-AWA) abrogated EMT and invasion by modulating ß-catenin localization and its transcriptional activity in the prostate as well as in breast cancer cells. This study, for the first time, reveals 3-AWA treatment consistently sequestered nuclear ß-catenin and augmented its cytoplasmic pool as evidenced by reducing ß-catenin transcriptional activity in these cells. Moreover, 3-AWA treatment triggered robust induction of pro-apoptotic intracellular Par-4, attenuated Akt activity and rescued Phospho-GSK3ß (by Akt) to promote ß-catenin destabilization. Further, our in vitro studies demonstrate that 3-AWA treatment amplified E-cadherin expression along with sharp downregulation of c-Myc and cyclin D1 proteins. Strikingly, endogenous Par-4 knock down by siRNA underscored 3-AWA mediated inhibition of nuclear ß-catenin was Par-4 dependent and suppression of Par-4 activity, either by Bcl-2 or by Ras transfection, restored the nuclear ß-catenin level suggesting Par-4 mediated ß-catenin regulation was not promiscuous. In vivo results further demonstrated that 3-AWA was effective inhibitor of tumor growth and immunohistochemical studies indicated that increased expression of total ß-catenin and decreased expression of phospho-ß-catenin and Par-4 in breast cancer tissues as compared to normal breast tissue suggesting Par-4 and ß-catenin proteins are mutually regulated and inversely co-related in normal as well as cancer condition. Thus, strategic regulation of intracellular Par-4 by 3-AWA in diverse cancers could be an effective tool to control cancer cell metastasis. Conclusively, this report puts forward a novel approach of controlling deregulated ß-catenin signaling by 3-AWA induced Par-4 protein.

Incidence of pseudotumor and acute lymphocytic vasculitis associated lesion (ALVAL) reactions in metal-on-metal hip articulations: a meta-analysis.

We systematically reviewed the peer-reviewed literature to determine a pooled estimate of the incidence of pseudotumor and acute lymphocytic vasculitis associated lesions (ALVAL) in adult patients with primary metal-on-metal (MoM) total hip arthroplasty or resurfacing. Fourteen eligible articles were identified, with a total of 13,898 MoM hips. The incidence of pseudotumor/ALVAL ranged from 0% to 6.5% of hips with a mean follow-up ranging from 1.7 to 12.3 years across the studies. The pooled estimated incidence of pseudotumor/ALVAL is 0.6% (95% CI: 0.3% to 1.2%). The rate of revision for any reason ranged from 0% to 14.3% of hips, with a pooled estimate of 3.9% (95% CI: 2.7% to 5.3%).

A novel MMP-2 inhibitor 3-azidowithaferin A (3-azidoWA) abrogates cancer cell invasion and angiogenesis by modulating extracellular Par-4.

BACKGROUND: Withaferin A, which is a naturally derived steroidal lactone, has been found to prevent angiogenesis and metastasis in diverse tumor models. It has also been recognized by different groups for prominent anti-carcinogenic roles. However, in spite of these studies on withanolides, their detailed anti-metastatic mechanism of action remained unknown. The current study has poised to address the machinery involved in invasion regulation by stable derivative of Withaferin A, 3-azido Withaferin A (3-azidoWA) in human cervical HeLa and prostate PC-3 cells. METHODS AND PRINCIPAL FINDINGS: Sub-toxic concentration of 3-azidowithaferin A (3-azido WA) inhibited cancer cell motility and invasion in wound healing and Boyden chamber invasion by suppressing MMP-2 activity in gelatin zymography and its expression has proved to be a major obstacle in chemo-sensitivity. We have uncovered a novel mechanism of 3-azidoWA induced extracellular pro-apoptotic candidate tumor suppressor Par-4 protein stimulation in conditioned media and also noticed a concomitant marked reduction in pAkt and pERK signaling by immunoblot analysis. Furthermore, our zymography results suggest 3-azidoWA induced MMP-2 inhibition was mediated through secretory Par-4. The inhibition of apoptosis by 3-azidoWA could not restore MMP-2 gelatinase activity. In addition to this, our in vivo animal experiments data showed 3-azidoWA abrogated neovascularisation in dose dependent manner in mouse Matrigel plug assay. CONCLUSION/SIGNIFICANCE: For this report, we found that 3-azidoWA suppressed motility and invasion of HeLa and PC-3 cells in MMP-2 dependent manner. Our in vitro result strongly suggests that sub-toxic doses of 3-azidoWA enhanced the secretion of extracellular Par-4 that abolished secretory MMP-2 expression and activity. Depletion of secretory Par-4 restored MMP-2 expression and invasion capability of HeLa and PC-3 cells. Further, our findings implied that 3-azidoWA attenuated internal phospho-ERK and phospho-Akt expression in a dose dependent manner might play a key role in inhibition of mouse angiogenesis by 3-azidoWA.