Ashraf Bakkar

Dr. Ashraf Bakkar


Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
14 June 2011 in Cancer Research
Verified
Journal Article
Open access
PDF file
ABAnaid Benitez
Anaid Benitez
TYTravis J. Yates
Travis J. Yates
LLLuis E. Lopez
Luis E. Lopez
WCWolfgang H. Cerwinka
Wolfgang H. Cerwinka
ABAshraf Bakkar
Ashraf Bakkar
VLVinata B Lokeshwar
Vinata B Lokeshwar
The tumor cell–derived hyaluronidase (HAase) HYAL-1 degrades hyaluronic acid (HA) into proangiogenic fragments that support tumor progression. Although HYAL-1 is a critical determinant of tumor progression and a marker for cancer diagnosis and metastasis prediction, it has not been evaluated as a target for cancer therapy. Similarly, sulfated hyaluronic acid (sHA) has not been evaluated for biological activity, although it is an HAase inhibitor. In this study, we show that sHA is a potent inhibitor of prostate cancer. sHA blocked the proliferation, motility, and invasion of LNCaP, LNCaP-AI, DU145, and LAPC-4 prostate cancer cells, and induced caspase-8–dependent apoptosis associated with downregulation of Bcl-2 and phospho-Bad. sHA inhibited Akt signaling including androgen receptor (AR) phosphorylation, AR activity, nuclear factor κB (NFκB) activation, and VEGF expression. These effects were traced to a blockade in complex formation between phosphoinositide 3-kinase (PI3K) and HA receptors and to a transcriptional downregulation of HA receptors, CD44, and RHAMM, along with PI3K inhibition. Angiogenic HA fragments or overexpression of myristoylated Akt or HA receptors blunted these effects of sHA, implicating a feedback loop between HA receptors and PI3K/Akt signaling in the mechanism of action. In an animal model, sHA strongly inhibited LNCaP-AI prostate tumor growth without causing weight loss or apparent serum-organ toxicity. Inhibition of tumor growth was accompanied by a significant decrease in tumor angiogenesis and an increase in apoptosis index. Taken together, our findings offer mechanistic insights into the tumor-associated HA–HAase system and a preclinical proof-of-concept of the safety and efficacy of sHA to control prostate cancer growth and progression. Cancer Res; 71(12); 4085–95. ©2011 AACR.

1 December 2003
Verified
Journal Article
Closed access
ABAshraf Bakkar
Ashraf Bakkar
HWHerve Wallerand
Herve Wallerand
FRFrancois Radvanyi
Francois Radvanyi
JLJean-Baptiste Lahaye
Jean-Baptiste Lahaye
SPSerge Pissard
Serge Pissard
SMSixtina Gil Diez De Medina
Sixtina Gil Diez De Medina

24 June 2004 in Carcinogenesis
Verified
Journal Article
Open access
PDF file
HWHervé Wallerand
Hervé Wallerand
ABAshraf Bakkar
Ashraf Bakkar
SMSixtina Gil Diez de Medina
Sixtina Gil Diez de Medina
JPJean-Claude Pairon
Jean-Claude Pairon
YYYu-Ching Yang
Yu-Ching Yang
DCDominique K. Chopin
Dominique K. Chopin
Smoking is a major risk factor for urothelial cell carcinoma of the bladder (UCC). Mutations in the FGFR3 and TP53 genes have been shown to define two distinct pathways in superficial papillary and invasive UCC disease, respectively. We investigated the relationship between smoking and these mutations by means of denaturing high performance liquid chromatography and sequencing for 110 primary UCC of the bladder. This study included 48 current smokers, 31 ex-smokers and 31 non-smokers. Thirty-five of the tumors were stage pTa, 40 pT1 and 35 ≥pT2. Fourteen of the tumors were grade 1, 37 were grade 2 and 59 grade 3. Smoking was associated with high stage (P = 0.03) and high grade tumors (P = 0.006). Twenty-two of the 110 tumors studied harbored TP53 mutations (20%) and 43 harbored FGFR3 mutations (39%). Odds ratios (OR) were higher for TP53 mutations in current smokers [OR, 2.25; 95% confidence interval (95% CI), 0.65–7.75] and ex-smokers (OR, 1.62; 95% CI, 0.41–6.42) than in non-smokers. Double TP53 mutations and the A:T→G:C TP53 mutation pattern was found only in current smokers. Patients with the FGFR3wild-type/TP53mutated genotype had significantly higher levels of tobacco consumption, as measured in pack-years (P = 0.01). Smoking influenced neither the frequency nor the pattern of FGFR3 mutations. Our results suggest that smoking is associated with invasive and high grade UCCs, at initial presentation, and influenced TP53 or the molecular pathway defined by these mutations. In contrast, FGFR3 mutations are not affected by smoking and probably result from endogenous alterations. These data have potential implications for clinical management and prevention strategies.

5 February 2024 in Cells
Verified
Journal Article
Open access
PDF file
AKAzza M. Khaled
Azza M. Khaled
MOMohamed Othman
Mohamed Othman
SOSofian Obeidat
Sofian Obeidat
GAGhada M. Aleid
Ghada M. Aleid
SAShimaa Aboelnaga
Shimaa Aboelnaga
DMDalia Morsi
Dalia Morsi
A well-known natural ingredient found in several medicinal plants, berberine (Ber), has been shown to have anticancer properties against a range of malignancies. The limited solubility and bioavailability of berberine can be addressed using Ber-loaded nanoparticles. In this study, we compared the in vitro cytotoxic effects of both Ber-loaded silver nanoparticles (Ber-AgNPs) and Ber-loaded selenium nanoparticles (Ber-SeNPs) in the human liver cancer cell line (HepG2) and mouse normal liver cells (BNL). The IC50 values in HepG2 for berberine, Ber-AgNPs, Ber-SeNPs, and cisplatin were 26.69, 1.16, 0.04, and 0.33 µg/mL, respectively. Our results show that Ber and its Ag and Se nanoparticles exerted a good antitumor effect against HepG2 cells by inducing apoptosis via upregulating p53, Bax, cytosolic cytochrome C levels, and caspase-3 activity, and the down-regulation of Bcl-2 levels. Similarly, incubation with Ber and both Ber-NPs (Ag and Se) led to a significant dose-dependent elevation in inflammatory markers’ (TNF-α, NF-κB, and COX-2) levels compared to the control group. In addition, it led to the arrest of the G1 cell cycle by depleting the expression of cyclin D1 and CDK-2 mRNA. Furthermore, Ber and both Ber-NPs (Ag and Se) caused a significant dose-dependent increase in LDH activity in HepG2 cells. Furthermore, our findings offer evidence that Ber and its nanoparticles intensified oxidative stress in HepG2 cells. Furthermore, the migration rate of cells subjected to berberine and its nanoforms was notably decreased compared to that of control cells. It can be inferred that Ber nanoparticles exhibited superior anticancer efficacy against HepG2 compared to unprocessed Ber, perhaps due to their improved solubility and bioavailability. Furthermore, Ber-SeNPs exhibited greater efficacy than Ber-AgNPs, possibly as a result of the inherent anticancer characteristics of selenium.

13 December 2012 in PLOS ONE
Verified
Journal Article
Open access
PDF file
YNYann Neuzillet
Yann Neuzillet
XPXavier Paoletti
Xavier Paoletti
SOSlah Ouerhani
Slah Ouerhani
PMPierre Mongiat-Artus
Pierre Mongiat-Artus
HSHany Soliman
Hany Soliman
FRFrancois Radvanyi
Francois Radvanyi
TP53 and FGFR3 mutations are the most common mutations in bladder cancers. FGFR3 mutations are most frequent in low-grade low-stage tumours, whereas TP53 mutations are most frequent in high-grade high-stage tumours. Several studies have reported FGFR3 and TP53 mutations to be mutually exclusive events, whereas others have reported them to be independent. We carried out a meta-analysis of published findings for FGFR3 and TP53 mutations in bladder cancer (535 tumours, 6 publications) and additional unpublished data for 382 tumours. TP53 and FGFR3 mutations were not independent events for all tumours considered together (OR = 0.25 [0.18–0.37], p = 0.0001) or for pT1 tumours alone (OR = 0.47 [0.28–0.79], p = 0.0009). However, if the analysis was restricted to pTa tumours or to muscle-invasive tumours alone, FGFR3 and TP53 mutations were independent events (OR = 0.56 [0.23–1.36] (p = 0.12) and OR = 0.99 [0.37–2.7] (p = 0.35), respectively). After stratification of the tumours by stage and grade, no dependence was detected in the five tumour groups considered (pTaG1 and pTaG2 together, pTaG3, pT1G2, pT1G3, pT2-4). These differences in findings can be attributed to the putative existence of two different pathways of tumour progression in bladder cancer: the CIS pathway, in which FGFR3 mutations are rare, and the Ta pathway, in which FGFR3 mutations are frequent. TP53 mutations occur at the earliest stage of the CIS pathway, whereas they occur would much later in the Ta pathway, at the T1G3 or muscle-invasive stage.

19 July 2011 in BJU International
Verified
Journal Article
Closed access
PDF file
LPLars F. Petersen
Lars F. Petersen
NBNigel T. Brockton
Nigel T. Brockton
ABAshraf Bakkar
Ashraf Bakkar
SLShuhong Liu
Shuhong Liu
JWJing Wen
Jing Wen
Tarek BismarTarek Bismar
Tarek Bismar