Elevated MED28 expression predicts poor outcome in women with breast cancer

Abstract Background MED28 (also known as EG-1 and magicin) has been implicated in transcriptional control, signal regulation, and cell proliferation. MED28 has also been associated with tumor progression in in vitro and in vivo models. Here we examined the association of MED28 expression with human breast cancer progression. Methods Expression of MED28 protein was determined on a population basis using a high-density tissue microarray consisting of 210 breast cancer patients. The association and validation of MED28 expression with histopathological subtypes, clinicopathological variables, and disease outcome was assessed. Results MED28 protein expression levels were increased in ductal carcinoma in situ and invasive ductal carcinoma of the breast compared to non-malignant glandular and ductal epithelium. Moreover, MED28 was a predictor of disease outcome in both univariate and multivariate analyses with higher expression predicting a greater risk of disease-related death. Conclusions We have demonstrated that MED28 expression is increased in breast cancer. In addition, although the patient size was limited (88 individuals with survival information) MED28 is a novel and strong independent prognostic indicator of survival for breast cancer

Specificity protein, Sp1-mediated increased expression of Prdx6 as a curcumin-induced antioxidant defense in lens epithelial cells against oxidative stress

Peroxiredoxin 6 (Prdx6) is a pleiotropic oxidative stress-response protein that defends cells against reactive oxygen species (ROS)-induced damage. Curcumin, a naturally occurring agent, has diversified beneficial roles including cytoprotection. Using human lens epithelial cells (hLECs) and Prdx6-deficient cells, we show the evidence that curcumin protects cells by upregulating Prdx6 transcription via invoking specificity protein 1 (Sp1) activity against proapoptotic stimuli. Curcumin enhanced Sp1 and Prdx6 mRNA and protein expression in a concentration-dependent manner, as evidenced by western and real-time PCR analyses, and thereby negatively regulated ROS-mediated apoptosis by blunting ROS expression and lipid peroxidation. Bioinformatic analysis and DNA–protein binding assays disclosed three active Sp1 sites (−19/27, −61/69 and −82/89) in Prdx6 promoter. Co-transfection experiments with Sp1 and Prdx6 promoter–chloramphenicol acetyltransferase (CAT) constructs showed that CAT activity was dramatically increased in LECs or Sp1-deficient cells (SL2). Curcumin treatment of LECs enhanced Sp1 binding to its sites, consistent with curcumin-dependent stimulation of Prdx6 promoter with Sp1 sites and cytoprotection. Notably, disruption of Sp1 sites by point mutagenesis abolished curcumin transactivation of Prdx6. Also, curcumin failed to activate Prdx6 expression in the presence of Sp1 inhibitors, demonstrating that curcumin-mediated increased expression of Prdx6 was dependent on Sp1 activity. Collectively, the study may provide a foundation for developing transcription-based inductive therapy to reinforce endogenous antioxidant defense by using dietary supplements

Debating the Desirability of New Biomedical Technologies: Lessons from the Introduction of Breast Cancer Screening in the Netherlands

Health technology assessment (HTA) was developed in the 1970s and 1980s to facilitate decision making on the desirability of new biomedical technologies. Since then, many of the standard tools and methods of HTA have been criticized for their implicit normativity. At the same time research into the character of technology in practice has motivated philosophers, sociologists and anthropologists to criticize the traditional view of technology as a neutral instrument designed to perform a specific function. Such research suggests that the tools and methods of more traditional forms of HTA are often inspired by an ‘instrumentalist’ conception of technology that does not fit the way technology actually works. This paper explores this hypothesis for a specific case: the assessments and deliberations leading to the introduction of breast cancer screening in the Netherlands. After reconstructing this history of HTA ‘in the making’ the stepwise model of HTA that emerged during the process is discussed. This model was rooted indeed in an instrumentalist conception of technology. However, a more detailed reconstruction of several episodes from this history reveals how the actors already experienced the inadequacy of some of the instrumentalist presuppositions. The historical case thus shows how an instrumentalist conception of technology may result in implicit normative effects. The paper concludes that an instrumentalist view of technology is not a good starting point for HTA and briefly suggests how the fit between HTA methods and the actual character of technology in practice might be improved

Basonuclin-Null Mutation Impairs Homeostasis and Wound Repair in Mouse Corneal Epithelium

At least two cellular processes are required for corneal epithelium homeostasis and wound repair: cell proliferation and cell-cell adhesion. These processes are delicately balanced to ensure the maintenance of normal epithelial function. During wound healing, these processes must be reprogrammed in coordination to achieve a rapid re-epithelialization. Basonuclin (Bnc1) is a cell-type-specific transcription factor expressed mainly in the proliferative keratinocytes of stratified epithelium (e.g., corneal epithelium, epidermis and esophageal epithelium) and the gametogenic cells in testis and ovary. Our previous work suggested that basonuclin could regulate transcription of ribosomal RNA genes (rDNA) and genes involved in chromatin structure, transcription regulation, cell-cell junction/communication, ion-channels and intracelllular transportation. However, basonuclin's role in keratinocytes has not been demonstrated in vivo. Here we show that basonuclin-null mutation disrupts corneal epithelium homeostasis and delays wound healing by impairing cell proliferation. In basonuclin-null cornea epithelium, RNA polymerase I (Pol I) transcription is perturbed. This perturbation is unique because it affects transcripts from a subset of rDNA. Basonuclin-null mutation also perturbs RNA polymerase II (Pol II) transcripts from genes encoding chromatin structure proteins histone 3 and HMG2, transcription factor Gli2, gap-junction protein connexin 43 and adheren E-cadherin. In most cases, a concerted change in mRNA and protein level is observed. However, for E-cadherin, despite a notable increase in its mRNA level, its protein level was reduced. In conclusion, our study establishes basonuclin as a regulator of corneal epithelium homeostasis and maintenance. Basonuclin likely coordinates functions of a subset of ribosomal RNA genes (rDNA) and a group of protein coding genes in cellular processes critical for the regulation of cell proliferation

MicroRNA-148a regulates LDL receptor and ABCA1 expression to control circulating lipoprotein levels

The hepatic low-density lipoprotein receptor (LDLR) pathway is essential for clearing circulating LDL cholesterol (LDL-C). Whereas the transcriptional regulation of LDLR is well characterized, the post-transcriptional mechanisms that govern LDLR expression are just beginning to emerge. Here we develop a high-throughput genome-wide screening assay to systematically identify microRNAs (miRNAs) that regulate LDLR activity in human hepatic cells. From this screen we identified and characterized miR-148a as a negative regulator of LDLR expression and activity and defined a sterol regulatory element binding protein 1 (SREBP1)-mediated pathway through which miR-148a regulates LDL-C uptake. In mice, inhibition of miR-148a increased hepatic LDLR expression and decreased plasma LDL-C. Moreover, we found that miR-148a regulates hepatic expression of ATP-binding cassette, subfamily A, member 1 (ABCA1) and circulating high-density lipoprotein cholesterol (HDL-C) levels in vivo. These studies uncover a role for miR-148a as a key regulator of hepatic LDL-C clearance through direct modulation of LDLR expression and demonstrate the therapeutic potential of inhibiting miR-148a to ameliorate an elevated LDL-C/HDL-C ratio, a prominent risk factor for cardiovascular disease