Hela Ben Nasr

Functional vascular endothelial growth factor − 2578 C/A polymorphism in relation to nasopharyngeal carcinoma risk and tumor progression

BACKGROUND Vascular endothelial growth factor (VEGF) is a mitogen for endothelial cells and a potent regulator of angiogenesis and inflammatory processes in nasopharyngeal carcinomas. In the current report, we designed a case-controlled study to evaluate whether a genetically predetermined variation in the VEGF expression may affect susceptibility and prognosis. METHODS A PCR and restriction fragment length polymorphism analysis was used to determine the variation of the -2578 C/A promoter region in a Tunisian population of patients with nasopharyngeal carcinomas (NPC) and in healthy control subjects. RESULTS A significantly risk of NPC was observed for carriers of VEGF -2578 C allele (OR=1.4; P=0.03). Regarding prognostic indicators, a significant association was found between -2578 C allele carriers and the aggressive forms of NPC as defined by large tumor size (OR=2.29; P=0.0002) and advanced tumor stages (OR=1.97; P=0.02). Moreover, an association was ascertained between the VEGF polymorphism and gender. CONCLUSIONS This is the first report on the studies of functional VEGF polymorphisms in NPC and our preliminary data suggest that this genetic variant may play a role in mediating susceptibility to NPC, as well as, in neoplastic progression, supporting our hypothesis for VEGF involvement in NPC etiology.

Calreticulin expression in infiltrating ductal breast carcinomas: relationships with disease progression and humoral immune responses

The aim of this study was to evaluate calreticulin expression in infiltrating ductal breast carcinomas (IDCAs), as well as its relationships with clinicopathological parameters of the disease. Using a two-dimensional gel electrophoresis/matrix-assisted laser desorption ionization time of flight mass spectrometry investigation coupled to an immunohistochemical approach, we have assessed the expression of calreticulin in IDCAs, as well as in other types of breast tumors. The humoral immune response against calreticulin was estimated using a serological proteomics-based strategy. Proteomic analyses revealed an increased expression of calreticulin in IDCA tumors. Using immunohistochemistry, overexpression of calreticulin was confirmed in 51 additional tumor specimens. Statistical analyses revealed, however, no significant correlations between calreticulin expression and clinicopathological parameters of the disease including tumor stage, patient age, SBR grade, and lymph node metastasis occurrence. A significant association was found, however, with estrogen receptor status. This study demonstrates the upregulation of calreticulin in IDCA tissues which may highlight its involvement in breast cancer development. Our findings also support a link between calreticulin expression and estrogen transduction pathways. Our results do not, however, support the involvement of calreticulin in the development of a humoral immune response in IDCAs.

Expression of the molecular chaperone αB-crystallin in infiltrating ductal breast carcinomas and the significance thereof: an immunohistochemical and proteomics-based strategy.

This study aims to evaluate αB-crystallin expression in infiltrating ductal breast carcinomas (IDCAs), as well as, its prognostic significance. Using a two-dimensional electrophoresis matrix-assisted laser desorption/ionisation-time of flight mass spectrometry investigation coupled to an immunohistochemical approach, we have assessed the expression of αB-crystallin in IDCAs, as well as, in other types of breast tumors (invasive lobular carcinomas, medullary carcinomas, and in situ ductal carcinomas). Correlation between αB-crystallin expression and clinicopathological parameters of breast cancer has also been investigated. Proteomic analyses revealed an increased expression of αB-crystallin in IDCA tumors compared to adjacent nontumor tissues. Overexpression of this molecular chaperone was further confirmed in 51 tumor specimens. Statistical analyses revealed, however, no significant correlations between αB-crystallin expression and clinicopathological parameters of the disease (tumor stage, patient age, hormone receptors, SBR grade, and lymph node metastases). This study demonstrates the upregulation of αB-crystallin in IDCA tissues which may highlight its possible involvement in breast cancer development. Our findings do not, however, support the involvement of this molecular chaperone in the progression of this disease.

An elongation factor-like protein (EF-Tu) elicits a humoral response in infiltrating ductal breast carcinomas: An immunoproteomics investigation

OBJECTIVES In the current study, we have used an immunoproteomics approach to identify proteins that commonly elicit a humoral response in patients with infiltrating ductal carcinomas of the breast. DESIGN AND METHODS Sera obtained at the time of diagnosis from 40 patients with invasive breast cancer and 42 healthy controls were screened for the presence of IgG antibodies to MCF-7 cell line proteins using a serological proteomics-based approach. RESULTS An immunoreactive protein detected in sera from 21 of 40 patients was isolated and subsequently identified as elongation factor-Tu. CONCLUSIONS The immunoproteomic approach implemented here offers a powerful tool for determining novel tumor antigens that induce a humoral immune response in cancer patients. From our findings, the immunoreactive EF-Tu protein and/or the related circulating antibodies may display clinical usefulness as potential diagnostic markers and provide a means for a better understanding of the molecular mechanisms underlying breast cancer development.

Expression and clinical significance of latent membrane protein-1, matrix metalloproteinase-1 and Ets-1 transcription factor in tunisian nasopharyngeal carcinoma patients.

BACKGROUND AND AIMS A prominent clinical feature of nasopharyngeal carcinoma (NPC) is its ability to easily invade local tissues and metastasize. In this field, latent membrane protein-1 (LMP-1), which is the principal Epstein-Barr virus-encoded oncoprotein, induces a set of factors that mediates angiogenesis and invasion. Matrix metalloproteinase-1 (MMP-1) and Ets-1 transcription factor are two other major factors that play crucial roles in tumor progression and may thus contribute to invasiveness of NPC cells. The aim of this study was to investigate the prognostic relevance of LMP-1 and its relationship with MMP-1 and Ets-1 expression in NPC biopsies. METHODS The expressions of LMP-1, MMP-1 and Ets-1 were immunohistochemically examined in 39 undifferentiated NPC specimens from Tunisian patients and the correlation between these proteins and clinicopathological parameters of the disease was statistically determined. RESULTS A significant association of LMP-1 expression with high T categories, as well as with the young age onset of NPC, has been found (p = 0.003). The expression of MMP-1 correlated with lymph node metastasis (p = 0.035), whereas a significant association between Ets-1 and high T categories, as well as distant metastasis, has been retrieved (p = 0.008; p = 0.047, respectively). In addition, the expression of LMP-1 showed a significant correlation with the expression of MMP-1 (p = 0.02). CONCLUSIONS The results of the current study suggest that LMP-1 may contribute to invasion and metastasis of undifferentiated NPCs through the induction of MMP-1.

Tropomyosin-4 correlates with higher SBR grades and tubular differentiation in infiltrating ductal breast carcinomas: an immunohistochemical and proteomics-based study

The aim of this study is to evaluate tropomyosin-4 (TM4) expression in infiltrating ductal breast carcinomas (IDCAs), as well as its prognostic significance. Using a 2-DE/MALDI-TOF mass spectrometry investigation coupled with an immunohistochemical approach, we have assessed the expression of TM4 in IDCAs, as well as in other types of breast tumors. Proteomic analyses revealed an increased expression of tropomyosin-4 in IDCA tumors. Using immunohistochemistry, overexpression of tropomyosin-4 was confirmed in 51 additional tumor specimens. Statistical analyses revealed, however, no significant correlations between tropomyosin-4 expression and clinicopathological parameters of the disease including tumor stage, patient age, estrogen and progesterone receptor status, and lymph node metastasis occurrence. A significant association was found, however, with a high Scarf–Bloom–Richardson (SBR) grade, a known marker of tumor severity. Additionally, the SBR component showing a correlation with TM4 expression was the tubular differentiation status. This study demonstrates the upregulation of tropomyosin-4 in IDCA tissues, which may highlight its involvement in breast cancer development. Our findings also support a link between tropomyosin-4 expression and aggressiveness of IDCA tumors.

Functional G894T (rs1799983) polymorphism and intron-4 VNTR variant of nitric oxide synthase (NOS3) gene are susceptibility biomarkers of obesity among Tunisians

OBJECTIVE The endothelial nitric oxide synthase (NOS3) has been shown to play a role in the modulation of lipolysis. The goal of this study was to examine the impact of the G894T (rs1799983) and a 27 bp variable number of tandem repeats (VNTR 4a/b) of NOS3 gene on obesity in a sample of the Tunisian population. RESEARCH METHODS AND PROCEDURES The study included 211 normal weight subjects and 183 obese patients. NOS3 G894T and 4a/b variants were determined by PCR analysis and examined for association with obesity-related traits. The effect of obesity on forearm skin blood flow (FSBF) response to acetylcholine, an endothelium-dependent vasodilator was determined by laser Doppler iontophoresis. RESULTS In case-control studies, both G894T and 4a/b variants were associated with obesity. A significantly increased risk of obesity was found with the NOS3(G894T) TT genotype (OR:2.62, P=0.04). This association remains significant after adjustments for age and gender (OR: 2.93, P=0.03). A higher risk was also observed for carriers of the G894T allele (OR: 1.72, P=0.001). Stratified analysis by gender revealed that obese men (but not women) had significantly higher frequency of TT genotypes compared to controls (9.9% vs. 2.9%, P=0.01). Carriers of the 4b allele presented a significantly higher risk of obesity than non-carriers even after adjustments for age and gender (OR (95%CI): 1.72 (1.16-2.56), P=0.004). Correlations with anthropometric parameters revealed that carriers of TT and bb genotypes had significantly higher body mass index compared to those homozygous for the G and a alleles (P=0.0004). CONCLUSION This study provides the first evidence for the association of G894T and 4a/b variants with body mass index and the risk of obesity in Tunisians. These polymorphisms did not exhibit, however any significant association with both metabolic traits and vascular function.

A single nucleotide polymorphism in the E-cadherin gene promoter —160 C/A is associated with risk of nasopharyngeal cancer

BACKGROUND E-cadherin is a cell structural protein that has a pivotal role in cell-cell adhesion and epithelial development. Up to now, loss of activity of E-cadherin is believed to contribute to progression in several neoplastic diseases of epidermoid origin including nasopharyngeal carcinomas (NPC) by increasing invasion and proliferation. Besides, functional genetic variations in the promoter region of the E-cadherin gene have been associated with susceptibility to several neoplasms. In the current study we investigated the impact of the functional C/A genetic polymorphism at -160 from transcriptional start site of the E-cadherin gene promoter on susceptibility and prognosis in NPC. METHODS A PCR and restriction fragment length polymorphism analysis was used to determine the variation of the -160C/A promoter region in a Tunisian population consisting of 162 NPC patients and 140 age matched healthy controls. Associations of the genetic markers with the clinicopathological parameters and the rates of the nasopharyngeal carcinoma-specific overall survival and the disease-free survival were also assessed. RESULTS A significantly increased risk of NPC was observed for carriers of E-cadherin -160A allele (OR=2.02; P=0.008). AA and CA genotypes entailed a 4.12 and 1.8 fold high risks, respectively for NPC compared to the CC genotype. Additionally, an association was ascertained between the E-cadherin polymorphism and the young age onset of NPC. CONCLUSIONS This is the first report on the studies of functional E-cadherin polymorphisms in NPC and our preliminary results suggest that the -160 C/A promoter polymorphism is associated with increased risk of nasopharyngeal carcinoma in the Tunisian population, especially in young patients.

Assessment of the clinical significance of antigenic and functional levels of α1-proteinase inhibitor (α1-Pi) in infiltrating ductal breast carcinomas

OBJECTIVES To determine the clinical significance of α1-proteinase inhibitor (α1-Pi) in infiltrating ductal breast carcinoma patients. DESIGN AND METHODS Serum levels of α1-Pi, tryptic specific inhibitory capacity and α1-Pi circulating immune complexes were determined using radial immunodiffusion, BAPNA assays and ELISA, respectively. 2-DE-MS and immunohistochemistry were performed to examine α1-Pi protein expression. RESULTS A decreased serum level of α1-Pi was found among breast cancer patients in comparison to controls. In addition, we found a significantly decreased mean level of α1-Pi in the node metastatic group when compared to node negative patients. However, the functional activity of the inhibitor did not decrease proportionately. Through 2-DE analyses, a differential expression of α1-Pi isoforms according to tumor stage and node metastatic development was found. CONCLUSIONS Both α1-Pi levels and specific activity could be a source of complementary clinical information and may provide useful information for a better understanding of the mechanisms of metastasis.

Role of MMP-1 (-519A/G, -1607 1G/2G), MMP-3 (Lys45Glu), MMP-7 (-181A/G), and MMP-12 (-82A/G) Variants and Plasma MMP Levels on Obesity-Related Phenotypes and Microvascular Reactivity in a Tunisian Population

Aims The impact of MMP-1 (-519A/G, -1607 1G/2G), MMP-3 Lys45Glu (A/G), MMP-7 -181A/G, and MMP-12 -82A/G variants and plasma MMP levels on obesity and microvascular reactivity in Tunisians. Methods Our population included 202 nonobese and 168 obese subjects. Anthropometric, biochemical, and microvascular parameters were determined according to standard protocols. PCR-RFLP and ELISA were used to determine the genetic variants and levels of MMPs, respectively. Results The MMP-3 45Glu (G) allele associates with higher anthropometric values and MMP-3 levels compared to AA genotype carriers (BMI (kg/m2): 30 ± 0.51 versus 27.33 ± 0.8, P = 0.004; MMP-3 levels: 7.45 (4.77–11.91) versus 5.21 (3.60–10.21) ng/ml, P = 0.006). The MMP-12 -82G allele was also associated with higher BMI values when compared to subjects carrying the AA genotype (31.41 ± 0.85 versus 28.76 ± 0.43, P < 0.001). Individuals carrying the MMP-3 45G or MMP-12 -82G variants were also associated with a higher risk for severe forms of obesity (MMP-3: OR = 1.9, P = 0.002; MMP-12: OR = 2.63, P = 0.003). Similarly, the MMP-7 -181G allele was associated with a higher MMP-7 level and an increased risk for morbid obesity when compared to AA genotype carriers (0.32 (0.31–0.60) versus 0.18 (0.17–0.24) ng/ml, P = 0.01; OR = 1.67, P = 0.02, resp.). Conclusion MMP-3, MMP-7, and MMP-12 polymorphisms associate with obesity risk and its severity.