It is well-known that estrogens immensely contribute to the progression of human breast carcinoma, but their detailed molecular mechanisms remain largely unclear. In this study, we identified nucleobindin 2 (NUCB2) as a gene associated with recurrence based on microarray data of estrogen receptor (ER)-positive breast carcinoma cases (n = 10), and subsequent in vitro study showed that NUCB2 expression was upregulated by estradiol in ER-positive MCF-7 cells. However, NUCB2 has not yet been examined in breast carcinoma, and its significance remains unknown. Therefore, we further examined the biological functions of NUCB2 in breast carcinoma using immunohistochemistry and in vitro studies. NUCB2 immunoreactivity was detected in carcinoma cells in 77 of 161 (48%) breast cancer cases, and positively associated with lymph node metastasis and ER status of the patients. In addition, NUCB2 status was significantly associated with an increased risk of recurrence and adverse clinical outcome of the patients using both univariate and multivariate analyses. Results of siRNA transfection experiments showed that NUCB2 significantly increased cell proliferation, and migration and invasion properties in both MCF-7 and ER-negative SK-BR-3 cells. These results suggest that NUCB2 is upregulated by estrogens and plays an important role, especially in the process of metastasis, in breast carcinomas. NUCB2 status is considered a potent prognostic factor in human breast cancer. (Cancer Sci 2012; 103: 136-143) B reast cancer is one of the most common malignancies in women. Estrogens play an important role in the progression of breast cancer through an interaction with ER, and ER is positive in approximately two-thirds of breast carcinoma cases. The great majority of ER-positive breast carcinomas respond to endocrine therapy such as tamoxifen and aromatase inhibitors, but it is also true that some of these carcinomas acquire clinical resistance to endocrine therapy. (1,2) Estrogen receptor activates the transcription of various target genes in a ligand-dependent manner by binding EREs located in the promoter region. Various estrogenic functions are characterized by the expression patterns of these genes, which make it extremely important to examine the expression and roles of estrogen-responsive genes to obtain a better understanding of estrogenic actions such as progression, recurrence, and resistance to endocrine therapy.(3) Various estrogen-responsive genes have been identified in breast carcinoma, (4,5) but their detailed clinical significance and ⁄ or function remain unclear in a great majority of these genes. Therefore, in this study, we first studied the expression profiles of genes containing ERE in ER-positive breast carcinoma tissues based on microarray data, and identified NUCB2 as a possible gene associated with recurrence in these patients.Nucleobindin 2 has a characteristic constitution of functional domains, such as a signal peptide, a Leu ⁄ Ile rich region, two Ca 2+ binding EF-hand domains separated by an acidic amino ...

Four mutations (C1939G, G3370T, 3746delG, and 4870delT) are relatively more prevalent in this population, accounting for 60% of the mutations in this study. This study revealed that the G3370T mutation was associated with milder forms of MM and the G3510A mutation was associated with a more severe form.

Runx2 has been proposed as one of the pivotal factors in the process of osteogenesis and metastasis in human malignancies including breast cancer, but its details have not been evaluated. Therefore, in this study, we evaluated its expression in human breast cancer using immunohistochemistry. One hundred and thirty-seven formalin-fixed and paraffin-embedded breast cancer specimens were used in this analysis of immunohistochemical study. Immunoreactivity was evaluated using the labeling index (LI). Runx2 immunoreactivity was detected in both carcinoma and stromal cells, as well as non-pathological ductal cells. The nuclear LI of Runx2 in carcinoma cells was associated with the clinical stage, histological grade and HER2 status of the patients examined. In addition, among the patients not associated with distant metastasis, those with high Runx2 LI demonstrated a significantly worse clinical outcome than those with a low LI. This was more pronounced in the group of estrogen receptor (ER)-negative cases. In addition, both univariate and multivariate analyses demonstrated that the Runx2 LI in breast carcinoma cells turned out an independent prognostic factor. Results of our present study demonstrated that Runx2 plays very important roles in the progression of breast cancer, especially in those of ER-negative cases. (Cancer Sci 2010; 101: 2670-2675 B reast cancer is one of the most common malignancies in women worldwide. Recently, the potential association of breast cancer with its bone metastasis has been evaluated from different perspectives and, in particular, the process of osteolysis itself in its metastatic sites has been proposed to facilitate breast cancer progression.(1) It is also well known that breast carcinoma cells themselves secrete parathyroid-hormone-related peptide (PTHrP), which stimulates osteoblasts in the microenvironment of bone metastatis.(2) Osteoblasts at the sites of metastasis are also considered to secrete a receptor activator of NFjB ligand (RANKL) to facilitate the process of transition from mesenchymal cells into functional osteoclasts, which subsequently resorb bone.(3-7) In normal human adult skeleton, bone is constantly renewed or maintained through the coordinated activities of both osteoclasts and osteoblasts.(8) Metastatic breast carcinoma cells are seeded into the bone microenvironment, which results in the maturation of osteoclasts.(9) These subsequently formed osteolytic foci are associated with bone resorption, which eventually leads to the release of growth factors including transforming growth factor-b (TGF-b) and several insulin-like growth factors (IGF) from the collapsed bone matrix.(10,11) These factors are considered to subsequently mediate tumor cell proliferation at the sites of bone metastasis.The Runt-related transcription factors 1-3 (Runxs1-3) have been shown to be required for the process of organogenesis, and mutations in these genes have been reported to be linked to several types of cancer development.(12) For instance, Runx1 and Runx3 mutations were reported...

The authors describe a patient with sporadic distal myopathy associated with reduced caveolin-3 in muscle fibers in which the muscle atrophy was restricted to the small muscles of the hands and feet. Gene analysis disclosed a heterozygous 80 G-->A substitution in the caveolin-3 gene that was identical to that of reported cases of elevated serum creatine kinase. This patient further demonstrated possible clinical heterogeneity of myopathies with mutations in the caveolin-3 gene.

Sex steroids play important roles in the development of many human breast carcinomas, and aromatase inhibitors are used for the anti-estrogen therapy. Recent studies have demonstrated that aromatase suppressed 5a-dihydrotestosterone (DHT) synthesis in breast carcinoma cells, but intratumoral concentration of androgens and its significance have not been reported in the breast carcinoma patients treated with aromatase inhibitors. Therefore, we examined androgen concentrations in breast carcinoma tissues treated with exemestane, and further performed in vitro studies to characterize the significance of androgen actions. Intratumoral DHT concentration was significantly higher in breast carcinoma tissues following exemestane treatment (nZ9) than those without the therapy (nZ7), and 17b-hydroxysteroid dehydrogenase type 2 (17bHSD2) status was significantly altered to be positive after the treatment. Following in vitro studies showed that 17bHSD2 expression was dose dependently induced by both DHT and exemestane in T-47D breast carcinoma cells, but these inductions were not additive. DHT-mediated induction of 17bHSD2 expression was markedly suppressed by estradiol (E 2 ) in T-47D cells. E 2 -mediated cell proliferation was significantly inhibited by DHT in T-47D cells, associated with an increment of 17bHSD2 expression level. These findings suggest that intratumoral androgen actions are increased during exemestane treatment. 17bHSD2 is a potent DHT-induced gene in human breast carcinoma, and may not only be involved in anti-proliferative effects of DHT on breast carcinoma cells but also serve as a potential marker for response to aromatase inhibitor in the breast carcinoma patients.

Aromatase inhibitors (AIs) are considered the gold standard of endocrine therapy for oestrogen receptor-positive postmenopausal breast cancer patients. AI treatment was reported to result in marked alterations of genetic profiles in cancer tissues but its detailed molecular mechanisms have not been elucidated. Therefore, we profiled miRNA expression before and after treatment with letrozole in MCF-7 co-cultured with primary breast cancer stromal cells. Letrozole significantly altered the expression profiles of cancer miRNAs in vitro. Among the elevated miRNAs following letrozole treatment, computational analysis identified let-7f, a tumour-suppressor miRNA which targeted the aromatase gene (CYP19A1) expression. Quantitative real-time PCR assay using MCF-7 and SK-BR-3 cells as well as clinical specimens of a neoadjuvant study demonstrated a significant inverse correlation between aromatase mRNA and let-7f expression. In addition, high let-7f expression was significantly correlated with low aromatase protein levels evaluated by both immunohistochemistry and the western blotting method in breast cancer cases. Results of 3'UTR luciferase assay also demonstrated the actual let-7f binding sites in CYP19A1, indicating that let-7f directly targets the aromatase gene. Subsequent WST-8 and migration assays performed in let-7f-transfected MCF-7 and SK-BR-3 cells revealed a significant decrement of their proliferation and migration. These findings all demonstrated that let-7f, a tumour suppressor miRNA in breast cancer, directly targeted the aromatase gene and was restored by AI treatment. Therefore, AIs may exert tumour-suppressing effects upon breast cancer cells by suppressing aromatase gene expression via restoration of let-7f.

Nuclear factor erythroid 2-related factor 2 (NRF2 (NFE2L2)) is an important transcriptional activator involved in the cellular defense mechanisms against electrophilic and oxidative stress. Recent studies have demonstrated that the expression of NRF2 protein is upregulated in several human malignancies and is associated with worse prognosis in these patients. However, the pathological and clinical significance of NRF2 has remained largely unknown in breast cancer patients. Therefore, in this study, we immunolocalized NRF2 in 106 breast carcinoma cases. NRF2 immunoreactivity was mainly detected in the nucleus of the breast carcinoma cells and it was positive in 44% of the cases. NRF2 status was significantly associated with histological grade, Ki-67 labeling index, p62 immunoreactivity, and NAD(P) H:quinone oxidoreductase 1 (NQO1) immunoreactivity, and the results of multivariate analyses revealed that NRF2 status was an independent adverse prognostic factor for both recurrence and disease-free survival of the patients. Subsequent in vitro studies demonstrated that the expression of NRF2 significantly increased the proliferation activity of MCF7 and SK-BR-3 breast carcinoma cells. These results indicate that nuclear NRF2 protein plays important roles in the proliferation and/or progression of breast carcinoma, and nuclear NRF2 immunoreactivity is therefore considered a potent prognostic factor in breast cancer patients.

Transcriptional dysregulation, which can be caused by genetic and epigenetic alterations, is a fundamental feature of many cancers. A key cytoprotective transcriptional activator, NRF2, is often aberrantly activated in non-small cell lung cancers (NSCLCs) and supports both aggressive tumorigenesis and therapeutic resistance. Herein, we find that persistently activated NRF2 in NSCLCs generates enhancers at gene loci that are not normally regulated by transiently activated NRF2 under physiological conditions. Elevated accumulation of CEBPB in NRF2-activated NSCLCs is found to be one of the prerequisites for establishment of the unique NRF2-dependent enhancers, among which the NOTCH3 enhancer is shown to be critical for promotion of tumor-initiating activity. Enhancer remodeling mediated by NRF2-CEBPB cooperativity promotes tumor-initiating activity and drives malignancy of NRF2-activated NSCLCs via establishment of the NRF2-NOTCH3 regulatory axis.