CD99 and HLA-II immunostaining in breast cancer tissue and their correlation with lymph node metastasis.

In an attempt to better unfold the antitumor immune response and invasion strategies perused by tumor cells, markers such as CD99 and HLA-II have been stained in breast tumors, some of them turned out to be important for prognosis and its outcome. CD99 is involved in the intracellular transport of HLA-II proteins. The expression of HLA-II and CD99 molecules has been demonstrated in a broader range of neoplastic tissues, including some epithelial tumors. In the present work, we stained CD99 and HLA-II in breast malignant and non-malignant tissues sections obtained from biopsies resected surgically from 80 Tunisian women. Data implied that CD99 marks malignant tissue significantly as compared to non-malignant breast tissue. HLA-II staining allowed determining the correlation between breast cancer and HLA-II with cytoplasmic localization. CD99 and HLA-II immunostaining was also examined in correlation with two of the most important breast cancer prognostication in routine clinical practice, the lymph node stage and the histological assessment. Results let suggest that CD99(+)HLA-II(-) is a marker of worst prognostic since this phenotype is strongly linked to lymph node metastasis in breast cancer.

Assessment of Aurora A kinase expression in breast cancer: a tool for early diagnosis?

Aurora A kinase is overexpressed in many cancers but the status of this protein in the breast cancer often varies. We investigate the expression and localization of Aurora A protein in relation with tumor emergence and progression in breast cancer. Aurora A kinase status was evaluated in 107 patients using immunohistochemistry. The experimental findings showed that high expression of the Aurora A protein was correlated with elevated nuclear grade, low expression of progesterone receptor and positive nodal status. The experimental results showed also that the localization of this kinase shifts from cytoplasm in non malignant adjacent tissue to both cytoplasmic and nuclear compartments in tumoral tissue, suggesting an oncogenic role of the nuclear accumulation. We have, furthermore, detected the overexpression of this protein in non malignant adjacent tissue. The expression of the Aurora A kinase in non malignant tissue may represent an earlier diagnosis tool for breast cancer.

Are HLA DQB1 alleles correlated with breast cancer histopronostic parameters in Tunisia?

BACKGROUND: Tumor cells express surface structures different from normal cells. These structures may be recognized by the immune system, which ensure anti-tumoral surveillance. Antigenic presentation requires HLA molecules role. Since, these molecules are encoded by a high polymorphic system, immune response can be modulated according to HLA genotype. So, HLA polymorphism could be correlated with tumor escape from anti-tumor immunosurveillance. AIM: We have aimed to search for possible associations between HLA DQB1 alleles and the histoprognostical parameters in breast cancer in the Tunisian population. METHODS: DQB1 alleles were determined by PCR-SSO molecular typing in 100 healthy matched and unrelated Tunisian female and 87 Tunisian women with breast cancer. RESULTS: Allelic distribution between the two studied groups showed no significant associations between this locus and the occurrence, the EE grade and the lymph node invasion of breast cancer in the Tunisian population. CONCLUSION: This result may be explained by the fact that cancer is a multifactoral disease due to several interacting factors that might change from one population to another.

[Polymorphism of the mitochondrial microsatellite 303-315 in breast cancer in Tunisia]. / Polymorphisme du microsatellite mitochondrial 303-315 dans le cancer du sein en Tunisie.

AIM: The aim of this work was to study the correlation between the mitochondrial microsatellite, situated between the nucleotides 303 and 315 of the mitochondrial genome and the breast cancer in Tunisia. MATERIALS AND METHODS: We have analyzed, by PCR-sequencing, the polymorphism of a mitochondrial microsatellite in 40 Tunisian patients and 39 healthy Tunisian donors. Comparisons of epidemiologic and sequences data were performed by chi-2 test. RESULTS: We have revealed, for this mitochondrial microsatellite, seven different haplotypes in patients and five different haplotypes in controls. The haplotypic distribution was not significant between patients and controls but a negative association between one of these haplotypes (309+C 315+C) and the lymph node invasion was found. CONCLUSION: The haplotype 309+C 315+C is negatively correlated with lymph node invasion of breast cancer in Tunisia.

[Penetrance of BRCA1 gene mutation and DNA mitochondrial in Tunisian breast cancer occurrence]. / Pénétrance des mutations du gène BRCA1 et de l'ADN mitochondrial dans l'occurrence du cancer du sein en Tunisie.

AIM: The aim of this study is to evaluate the implication of BRCA1 gene and the mitochondrial micro satellite (situated between 303 and 315 positions) mutations in the occurrence of breast cancer in Tunisia. METHODS: Nine Tunisian patients with hereditary breast cancer have been analyzed. For each patient, total genomic DNA was extracted and used as a template for the amplification of 24 exons of the BRCA1 gene and an hyper variable mitochondrial region. The obtained products were purified and automatically sequenced. RESULTS: The results revealed five types of mutations for the micro satellite situated between the 303 and 315 positions and two deleterious BRCA1 mutations for two unrelated patients which present the same mitochondrial mutation (315.insC) suggesting his implication in the modulation of the BRCA1 deleterious mutations penetrance.