Lotfi Chouchane

Leptin and leptin receptor polymorphisms are associated with increased risk and poor prognosis of breast carcinoma

BackgroundLeptin (LEP) has been consistently associated with angiogenesis and tumor growth. Leptin exerts its physiological action through its specific receptor (LEPR). We have investigated whether genetic variations in LEPand LEPRhave implications for susceptibility to and prognosis in breast carcinoma.MethodsWe used the polymerase chain reaction and restriction enzyme digestion to characterize the variation of the LEPand LEPRgenes in 308 unrelated Tunisian patients with breast carcinoma and 222 healthy control subjects. Associations of the clinicopathologic parameters and these genetic markers with the rates of the breast carcinoma-specific overall survival (OVS) and the disease free survival (DFS) were assessed using univariate and multivariate analyses.ResultsA significantly increased risk of breast carcinoma was associated with heterozygous LEP (-2548) GA(OR = 1.45; P = 0.04) and homozygous LEP (-2548) AA(OR = 3.17; P = 0.001) variants. A highly significant association was found between the heterozygous LEPR 223QRgenotype (OR = 1.68; P = 0.007) or homozygous LEPR 223RRgenotype (OR = 2.26; P = 0.001) and breast carcinoma.Moreover, the presence of the LEP (-2548) Aallele showed a significant association with decreased disease-free survival in breast carcinoma patients, and the presence of the LEPR 223Rallele showed a significant association with decreased overall survival.ConclusionOur results indicated that the polymorphisms in LEPand LEPRgenes are associated with increased breast cancer risk as well as disease progress, supporting our hypothesis for leptin involvement in cancer pathogenesis.

Expression of Human Papillomavirus Type 16 Major Capsid Protein L1 in Transgenic Arabidopsis thaliana

Plants are currently used as a cost-effective and safe heterologous expression system for the production of experimental vaccines. Here, we describe the expression of the HPV16 L1 protein in Arabidopsis thaliana. The HPV16 major capsid gene L1 sequence was extracted by digestion from the plasmid pMOS-L1 HPV16 containing the template sequence and cloned into the binary vector pBI121 consecutively to obtain the plant expression plasmid pBI-L1. The T-DNA regions of the pBI-L1 binary vector were cloned under the control of the constitutive cauliflower mosaic virus 35S promoter and the neomycin phosphotransferase nptII gene; the vector allowed the selection of transformed plants using kanamycin. The Arabidopsis plants were transformed by floral dip method, using Agrobacterium tumefaciens GV3101, which harbored the plant expression plasmid. The generated transgenic Arabidopsis plants were selected on a kanamycin-added Murashige–Skoog medium, and the integration and the stability of the L1 gene in plant genome were confirmed by polymerase chain reaction (PCR) amplification in three successive generations. The evidence for mRNA expression was acquired by reverse transcriptase PCR analysis. To identify further integration of transgene into the genome of A. thaliana, Southern blot assay was carried out and showed that the HPV16 L1 gene was integrated stably into the genome of the transformed Arabidopsis plants. Furthermore, Western blot analysis showed that transformed Arabidopsis plants produce HPV16 L1 protein. Thus, HPV16 L1 protein expressed in transgenic Arabidopsis plants can be potentially used as an edible vaccine.