Regulatory T cells in chronic lymphocytic leukemia: implication for immunotherapeutic interventions.

Identification of regulatory T cells (Tregs) has led to breaking the dichotomy of the Th1/Th2 axis in the immunopathology of several diseases such as autoimmune diseases and cancer. Despite the presence of extensive information about immunobiology of Tregs in pathogenesis of autoimmune diseases, little is known about the frequency and function of these cells in hematologic malignancies, particularly chronic lymphocytic leukemia (CLL). Recent data have demonstrated increased frequency and intact functional capacity of CD4(+) Tregs in CLL patients. However, the precise role of these cells in the immunopathology of CLL is not well known. While targeting Tregs in cancer diseases seems to be an interesting immunotherapeutic approach, such therapeutic interventions in CLL might be deleterious due to suppression of the tumor-specific adaptive and innate immune responses. Thus, the precise biological and regulatory functions of all Tregs subsets should be carefully investigated before planning any immunotherapeutic interventions based on targeting of Tregs. In this communication, we review the recent data published on immunobiology of Tregs in CLL and discuss about the possibility of targeting Tregs in CLL.

Gene amplification and overexpression of Aurora-C in breast and prostate cancer cell lines.

Human aurora kinases are three highly conserved serine/threonine kinases with regulatory function in chromosome alignment, chromosome segregation, and cytokinesis during cell cycle progression and their overexpression associates with malignant transformation and proliferation of cancer cells. Aurora genes are located at loci that are commonly altered in cancers. Aurora-A has oncogenic activity while Aurora-B does not. Aurora-C is only detected in mammals with involvement in meiosis. Oncogenic activity of Aurora-C is still in dispute. We evaluated the expression of three Aurora kinases by real-time RT-PCR in well-known breast and prostate cancer cell lines. Cell cycle was studied with flow cytometry. In both more invasive cell lines' p53-null cells, PC-3 and MDA-MB-231, an increase in mRNA expression of three Aurora kinases, especially Aurora-C, was observed. Genomic DNA was examined for gene amplification and aneuploidy as a mechanism of overexpression. At DNA level, only Aurora-C showed gene amplification in breast cancer cell lines (p < 0.005). Here we provide evidence for the first time of Aurora-C overexpression and gene amplification.

Detection of Duchenne/Becker muscular dystrophy carriers in a group of Iranian families by linkage analysis.

This study determines the value of linkage analysis using six RFLP markers for carrier detection and prenatal diagnosis in familial DMD/BMD cases and their family members for the first time in the Iranian population. We studied the dystrophin gene in 33 unrelated patients with clinical diagnosis of DMD or BMD. Subsequently, we determined the rate of heterozygosity for six intragenic RFLP markers in the mothers of patients with dystrophin gene deletions. Finally, we studied the efficiency of linkage analysis by using RFLP markers for carrier status detection of DMD/BMD. In 63.6% of the patients we found one or more deletions. The most common heterozygous RFLP marker with 57.1% heterozygosity was pERT87.15Taq1. More than 80% of mothers in two groups of familial or non-familial cases had at least two heterozygous markers. Family linkage analysis was informative in more than 80% of the cases, allowing for accurate carrier detection. We found that linkage analysis using these six RFLP markers for carrier detection and prenatal diagnosis is a rapid, easy, reliable, and inexpensive method, suitable for most routine diagnostic services. The heterozygosity frequency of these markers is high enough in the Iranian population to allow carrier detection and prenatal diagnosis of DMD/BMD in more than 80% of familial cases in Iran.

Autocrine human growth hormone expression leads to resistance of MCF-7 cells to tamoxifen.

Tamoxifen is the most common antiestrogen used in the treatment of estrogen-positive breast cancer but its adverse effects and also resistance to this drug are serious challenges in the treatment of breast cancer. Characterization of mechanisms responsible for these adverse effects can lead to design of more efficient therapeutic strategies for the treatment of breast cancer. Here, we used a cellular model to evaluate the effects of autocrine expression of human growth hormone on responses of cells to tamoxifen. Our results imply for the first time that autocrine expression of growth hormone in human breast adenocarcinoma cell line, MCF-7, results in increase in cell proliferative capacity of cells even in the presence of tamoxifen. This effect may be due to up-regulation of G-coupled estrogen receptor, GPR30, which is activated by tamoxifen.