Establishment and characterization of a prostate cancer cell line from a prostatectomy specimen for the study of cellular interaction.

Though human prostate cancer (PCa) heterogeneity can best be studied using multiple cell types isolated from clinical specimens, the difficulty of establishing cell lines from clinical tumors has hampered this approach. In this proof-of-concept study, we established a human PCa cell line from a prostatectomy surgical specimen without the need for retroviral transduction. In a previous report, we characterized the stromal cells derived from PCa specimens. Here, we characterized the epithelial cells isolated from the same tumors. Compared to the ease of establishing prostate stromal cell lines, prostatic epithelial cell lines are challenging. From three matched pairs of normal and tumor tissues, we established one new PCa cell line, HPE-15. We confirmed the origin of HPE-15 cells by short tandem repeat microsatellite polymorphism analysis. HPE-15 cells are androgen-insensitive and express marginal androgen receptor, prostate-specific antigen and prostate-specific membrane antigen proteins. HPE-15 expresses luminal epithelial markers of E-cadherin and cytokeratin 18, basal cell markers of cytokeratin 5 and p63 and neuroendocrine marker of chromogranin A. Interestingly, HPE-15 Cells exhibited no tumorigenicity in different strains of immune-deficient mice but can become tumorigenic through interaction with aggressive cancer cell types. HPE-15 cells can thus serve as an experimental model for the study of PCa progression, metastasis and tumor cell dormancy.

Public Mistrust of the U.S. Health Care System's Profit Motives: Mixed-Methods Results from a Randomized Controlled Trial.

BACKGROUND: Decision makers are increasingly tasked with reducing health care costs, but the public may be mistrustful of these efforts. Public deliberation helps gather input on these types of issues by convening a group of diverse individuals to learn about and discuss values-based dilemmas. OBJECTIVE: To explore public perceptions of health care costs and how they intersect with medical mistrust. DESIGN AND PARTICIPANTS: This mixed-methods study analyzed data from a randomized controlled trial including four public deliberation groups (n = 96) and a control group (n = 348) comprising English-speaking adults aged 18 years and older. Data were collected in 2012 in four U.S. regions. APPROACH: We used data from four survey items to compare attitude shifts about costs among participants in deliberation groups to participants in the control group. We qualitatively analyzed deliberation transcripts to identify themes related to attitude shifts and to provide context for quantitative results about attitude shifts. KEY RESULTS: Deliberation participants were significantly more likely than control group participants to agree that doctors and patients should consider cost when making treatment decisions (ß = 0.59; p < 0.01) and that people should consider the effect on group premiums when making treatment decisions (ß = 0.48; p < 0.01). Qualitatively, participants mistrusted the health care system's profit motives (e.g., that systems prioritize making money over patient needs); however, after grappling with patient/doctor autonomy and learning about and examining their own views related to costs during the process of deliberation, they largely concluded that payers have the right to set some boundaries to curb costs. CONCLUSIONS: Individuals who are informed about costs may be receptive to boundaries that reduce societal health care costs, despite their mistrust of the health care system's profit motives, especially if decision makers communicate their rationale in a transparent manner. Future work should aim to develop transparent policies and practices that earn public trust.

Setting Boundaries: Public Views on Limiting Patient and Physician Autonomy in Health Care Decisions.

We obtained and qualitatively analyzed input from more than nine hundred citizens during seventy-six public deliberation sessions about patient and physician autonomy in decision making, setting health care boundaries, and the tensions among competing social values. Generally, participants resisted interference with the patient-physician relationship and believed strongly in the freedom of patient and physician to control individual medical decisions. However, during deliberation participants identified two situations where boundaries and regulations in health care were more acceptable: protecting people from harm and allocating limited resources. The core value of individual freedom was tempered in varying degrees by the values of concern for the greater good and fairness in allocating resources. Where tensions between values emerged, participants used different concepts-including accountability, transparency, trust, personal responsibility, and moral obligation-to navigate trade-offs. Fairly balancing the public's desire to protect individual freedom with their sense of responsibility for protecting the common good may be the key to developing acceptable, workable policies that promote evidence-based medical practice.

Mutant p53 gains oncogenic functions through a chromosomal instability-induced cytosolic DNA response.

Inactivating TP53 mutations leads to a loss of function of p53, but can also often result in oncogenic gain-of-function (GOF) of mutant p53 (mutp53) proteins which promotes tumor development and progression. The GOF activities of TP53 mutations are well documented, but the mechanisms involved remain poorly understood. Here, we study the mutp53 interactome and find that by targeting minichromosome maintenance complex components (MCMs), GOF mutp53 predisposes cells to replication stress and chromosomal instability (CIN), leading to a tumor cell-autonomous and cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-dependent cytosolic DNA response that activates downstream non-canonical nuclear factor kappa light chain enhancer of activated B cell (NC-NF-κB) signaling. Consequently, GOF mutp53-MCMs-CIN-cytosolic DNA-cGAS-STING-NC-NF-κB signaling promotes tumor cell metastasis and an immunosuppressive tumor microenvironment through antagonizing interferon signaling and regulating genes associated with pro-tumorigenic inflammation. Our findings have important implications for understanding not only the GOF activities of TP53 mutations but also the genome-guardian role of p53 and its inactivation during tumor development and progression.

Essential role of limiting telomeres in the pathogenesis of Werner syndrome.

Mutational inactivation of the gene WRN causes Werner syndrome, an autosomal recessive disease characterized by premature aging, elevated genomic instability and increased cancer incidence. The capacity of enforced telomerase expression to rescue premature senescence of cultured cells from individuals with Werner syndrome and the lack of a disease phenotype in Wrn-deficient mice with long telomeres implicate telomere attrition in the pathogenesis of Werner syndrome. Here, we show that the varied and complex cellular phenotypes of Werner syndrome are precipitated by exhaustion of telomere reserves in mice. In late-generation mice null with respect to both Wrn and Terc (encoding the telomerase RNA component), telomere dysfunction elicits a classical Werner-like premature aging syndrome typified by premature death, hair graying, alopecia, osteoporosis, type II diabetes and cataracts. This mouse model also showed accelerated replicative senescence and accumulation of DNA-damage foci in cultured cells, as well as increased chromosomal instability and cancer, particularly nonepithelial malignancies typical of Werner syndrome. These genetic data indicate that the delayed manifestation of the complex pleiotropic of Wrn deficiency relates to telomere shortening.

Chromosome size affects sequence divergence between species through the interplay of recombination and selection.

The structure of the genome shapes the distribution of genetic diversity and sequence divergence. To investigate how the relationship between chromosome size and recombination rate affects sequence divergence between species, we combined empirical analyses and evolutionary simulations. We estimated pairwise sequence divergence among 15 species from three different mammalian clades-Peromyscus rodents, Mus mice, and great apes-from chromosome-level genome assemblies. We found a strong significant negative correlation between chromosome size and sequence divergence in all species comparisons within the Peromyscus and great apes clades but not the Mus clade, suggesting that the dramatic chromosomal rearrangements among Mus species may have masked the ancestral genomic landscape of divergence in many comparisons. Our evolutionary simulations showed that the main factor determining differences in divergence among chromosomes of different sizes is the interplay of recombination rate and selection, with greater variation in larger populations than in smaller ones. In ancestral populations, shorter chromosomes harbor greater nucleotide diversity. As ancestral populations diverge, diversity present at the onset of the split contributes to greater sequence divergence in shorter chromosomes among daughter species. The combination of empirical data and evolutionary simulations revealed that chromosomal rearrangements, demography, and divergence times may also affect the relationship between chromosome size and divergence, thus deepening our understanding of the role of genome structure in the evolution of species divergence.

Stakeholder-driven principles for advancing equity through shared measurement.

OBJECTIVE: To advance equity by developing stakeholder-driven principles of shared measurement, which is using a common set of measurable goals that reflect shared priorities across communities and systems, such as health care, public health, and human and social services. DATA SOURCES: From October 2019 to July 2021, we collected primary data from leaders in cross-systems alignment, measurement, and community engagement-including community members and community-based organization leaders-across the United States. STUDY DESIGN: In partnership with equity and community engagement experts, we conducted a mixed-methods study that included multiple formative research activities and culminated in a six-week, stakeholder-engaged modified-Delphi process. DATA COLLECTION: Formative data collection occurred through an environmental scan, interviews, focus groups, and an online survey. Principles were developed using a virtual modified Delphi with iterative rapid-analysis. Feedback on the final principles was collected through virtual focus groups, an online feedback form, and during virtual presentations. PRINCIPAL FINDINGS: We developed a set of five guiding principles. Measurement that aligns systems with communities toward equitable outcomes: (1) Requires upfront investment in communities; (2) Is co-created by communities; (3) Creates accountability to communities for addressing root causes of inequities and repairing harm; (4) Focuses on a holistic and comprehensive view of communities that highlights assets and historical context; and (5) Reflects long-term efforts to build trust. Using an equity-focused process resulted in principles with broad applicability. CONCLUSIONS: Leaders across systems and communities can use these shared measurement principles to reimagine and transform how systems create equitable health by centering the needs and priorities of the communities they serve, particularly communities that historically have been harmed the most by inequities. Intentionally centering equity across all project activities was essential to producing principles that could guide others in advancing equity.

Tackling ethical issues in health technology assessment: a proposed framework.

OBJECTIVES: Values are intrinsic to the use of health technology assessments (HTAs) in health policy, but neglecting value assumptions in HTA makes their results appear more robust or normatively neutral than may be the case. Results of a 2003 survey by the International Network of Agencies for Health Technology Assessment (INAHTA) revealed the existence of disparate methods for making values and ethical issues explicit when conducting HTA. METHODS: An Ethics Working Group, with representation from sixteen agencies, was established to develop a framework for addressing ethical issues in HTA. Using an iterative approach, with email exchanges and face-to-face workshops, a report on Handling Ethical Issues was produced. RESULTS: This study describes the development process and the agreed upon framework for reflexive ethical analysis that aims to uncover and explore the ethical implications of technologies through an integrated, context-sensitive approach and situates the proposed framework within previous work in the development of ethics analysis in HTA. CONCLUSIONS: It is important that methodological approaches to address ethical reflection in HTA be integrative and context sensitive. The question-based approach described and recommended here is meant to elicit this type of reflection in a way that can be used by HTA agencies. The questions proposed are considered only as a starting point for handling ethics issues, but their use would represent a significant improvement over much of the existing practice.

9-bromonoscapine-induced mitotic arrest of cigarette smoke condensate-transformed breast epithelial cells.

In the present investigation, we determined the chemotherapeutic efficacy of 9-bromonoscapine (Br-Nos), a more potent noscapine analog, on MCF10A, spontaneously immortalized human normal breast epithelial cells and MCF10A-CSC3, cigarette smoke condensate (CSC)-transformed cells. The results from cytogenetic analysis showed that Br-Nos induced polyploidy and telomeric association in MCF10A-CSC3 cells, while MCF10A cells remained unaffected. Our immunofluorescence data further demonstrated that MCF10A-CSC3 cells were susceptible to mitotic catastrophe on exposure to Br-Nos and failed to recover after drug withdrawal. MCF10A-CSC3 cells exhibited Br-Nos-induced aberrant multipolar spindle formation, which irreversibly impaired the alignment of replicated chromosome to the equatorial plane and finally culminated in cell death. Although MCF10A cells upon Br-Nos treatment showed bipolar spindles with some uncongressed chromosomes, these cells recovered fairly well after drug withdrawal. Our flow-cytometry analysis data reconfirmed that MCF10A-CSC3 cells were more susceptible to cell death compared to MCF10A cells. Furthermore, our results suggest that decreased levels of cdc2/cyclin B1 and cdc2 kinase activity are responsible for Br-Nos-induced mitotic cell arrest leading to cell death in MCF10A-CSC3 cells. This study thus explores the underlying mechanism of Br-Nos-induced mitotic catastrophe in CSC-transformed MCF10A-CSC3 cells and its potential usefulness as a chemotherapeutic agent for prevention of cigarette smoke-induced breast cancer growth.

Evidence that senescent human prostate epithelial cells enhance tumorigenicity: cell fusion as a potential mechanism and inhibition by p16INK4a and hTERT.

Normal human prostate (NHP) epithelial cells undergo senescence in vitro and in vivo but the potential role of senescent NHP cells in prostate tumorigenesis remain unclear. Here we show that senescent NHP cells enhance the in vivo tumorigenicity of low-tumorigenic LNCaP prostate cancer and low/non-tumorigenic subset of cells (called L cells) isolated from multiple bulk-cultured prostate (and other) cancer cell lines. Subsequent studies suggest cell-cell fusion as a potential mechanism for senescent NHP cell-enhanced tumor development. Using fluorescently tagged tumor cells and/or NHP cells, we find that NHP cells, like fibroblasts, can undergo fusion with unfractionated tumor cells or the L cells. Using 293T-L cells as the model cell system, we verify NHP and 293T-L cell fusion by using differential RT-PCR, karyotyping, and gene expression analyses. Further experiments demonstrate that senescent NHP cells that have lost progenitor markers, accumulated p16INK4a (p16) protein expression, and acquired the AR mRNA expression, appear to be the preferential fusion targets. Strikingly, the tumorigenicity of the NHP/293T-L hybrid cells was inhibited by exogenous p16 as well as hTERT. Chromosomal analyses revealed that hTERT probably inhibited the in vivo tumorigenicity by maintaining genomic stability. These results suggest that senescent NHP cells, like senescent fibroblasts, may promote tumor development and that one of the mechanisms underlying the senescent NHP cell-enhanced tumorigenicity could be through cell fusion.

Molecular analysis of anoikis resistance in oral cavity squamous cell carcinoma.

Oral cavity squamous cell carcinoma (OSCC) is one of the leading causes of cancer deaths worldwide and most of these deaths result from local-regional recurrence and metastases. Evasion of apoptosis is an important hallmark of cancer development and progression, and previous studies have shown that evasion of anoikis, or detachment-induced apoptosis, correlates with a more aggressive phenotype of carcinoma cells in OSCC. To elucidate the cytogenetic and molecular characteristics of anoikis resistance, we generated several cell lines and clones that displayed this cellular phenotype. To test the hypothesis that chromosomal alterations may underlie this phenotypic transformation, we used karyotype analysis to observe changes in the chromosomal structure of anoikis-sensitive and anoikis-resistant cell lines. We further hypothesized that a unique pattern of gene expression was induced by cell-detachment of anoikis-resistant cell lines, and cDNA microarray analysis was performed using a panel of anoikis-resistant oral cancer cell lines grown under attached and detached growth conditions. We identified S100P, KLK6 and CTNNAL1 as genes whose expression levels were differentially regulated in the anoikis-resistant cell lines compared to the anoikis-sensitive cells under detached conditions. These results were verified using real-time RT-PCR. The anoikis-resistant phenotype of squamous cell carcinoma has a distinct genetic expression pattern that is marked by chromosomal alterations that may contribute to differential expression of genes involved in diverse cellular functions. Therapies targeting these potential mediators of anoikis resistance may prove to be beneficial in the treatment of metastatic squamous cell carcinoma.

Aneuploidy, stem cells and cancer.

Telomeres which protect the individual chromosomes from disintegration, end-to-end fusion and maintain the genomic integrity during the somatic cell divisions play an important role in cellular aging. Aging and cancer development are linked with each other because cancer is considered a group of complex genetic diseases that develop in old cells and, in both, telomere attrition is involved. Numeric chromosome imbalance also known as aneuploidy is the hallmark of most solid tumors, whether spontaneous or induced by carcinogens. We provide evidence in support of the hypothesis that telomere attrition is the earliest genetic alteration responsible for the induction of aneuploidy. Dysfunctional telomeres are highly recombinogenic leading to the formation of dicentric chromosomes. During cell divisions, such complex chromosome alterations undergo breakage fusion bridge cycles and may lead to loss of heterozygosity (LOH) and gene amplification. Furthermore, we have provided evidence in support of the hypothesis that all types of cancer originate in the organ- or tissue-specific stem cells present in a particular organ. Cancer cells and stem cells share many characteristics, such as, self-renewal, migration, and differentiation. Metaphases with abnormal genetic constitution present in the lymphocytes of cancer patients and in some of their asymptomatic family members may have been derived from the organ-specific stem cells. In addition, evidence and discussion has been presented for the existence of cancer-specific stem cells. Successful treatment of cancer, therefore, should be directed towards these cancer stem cells.

In vivo opossum xenograft model for cancer research.

The inadequacies of athymic mice for research with grafted tumors are well known. Monodelphis domestica, the laboratory opossum, has the potential to complement the rodent model because of the immunoincompetent window period during early marsupial development. We injected pups of different ages with mouse melanoma cells and human melanoma, colon, and prostate cancer cells. The results showed that the xenogeneic tumors can grow and metastasize. We also obtained positive results by heterotopically injecting juveniles with mouse melanoma cells. These results establish Monodelphis as a natural mammalian model to study the cascade of interactions between xenografted cells and the host system.

Molecular characterization of new melanoma cell lines from C3H mice induced by ethanol plus ultraviolet radiation.

A major obstacle in understanding the etiology of malignant melanoma is the lack of mouse models and transplantable cell lines. We have recently developed a model of primary melanoma in C3H mice induced by ethanol and UV light. The present study characterizes three cell lines, SM190.2, SM190.626, and SD0302, derived from two melanomas produced in the dorsal skin of two C3H mice treated thrice weekly for 28-33 weeks with UV radiation and ethanol. In both tumors, the N-ras oncogene was mutated. Tumor SM190 lacked exon 2 of the p16(INK4a) tumor suppressor gene. Cell line SM190.2, which was derived from tumor SM190, produced pigmented tumors when transplanted into syngeneic severe combined immunodeficient mice and normal mice. None of the cell lines produced metastases. All three cell lines were highly aneuploid, even at low passage numbers. SM190.2 and SD0302 cells contained an interstitial deletion in the long arm of chromosome 4, where the p16(INK4a) gene resides, and SM190.2 had an additional segment in chromosome 6. The third cell line, SM190.626, had three consistent Robertsonian translocation markers involving chromosomes 7, 14, and 17. The translocation involving mouse chromosome 14 may prove especially valuable because translocations in this chromosome are associated with metastatic behavior. These reagents will provide opportunities to search for new tumor suppressor genes that may contribute to the growth and metastasis of primary melanoma.

Disruption of the NAD(P)H:quinone oxidoreductase 1 (NQO1) gene in mice causes myelogenous hyperplasia.

NAD(P)H:quinone oxidoreductase1 (NQO1) is a cytosolic protein that reduces and detoxifies quinones and their derivatives, thus protecting cells against redox cycling and oxidative stress. Disruption of the NQO1 gene in mice caused myeloid hyperplasia of bone marrow and highly significant increases in blood neutrophils, eosinophils, and basophils. NQO1-null mice also showed a decrease in lymphocytes and WBCs as compared with wild-type mice. Various techniques also demonstrated an increase in megakaryocytes without an increase in blood platelets. Histological analysis of liver, kidney, spleen, and thymus did not demonstrate a difference between wild-type and NQO1-null mice or a sign of infection. Blood cultures and urine analysis also did not demonstrate any sign of infection in NQO1-null and wild-type mice. Additional analysis of the bone marrow from NQO1-null mice revealed that loss of NQO1 alters the intracellular redox status because of accumulation of NAD(P)H, cofactors for NQO1. This causes a reduction in the levels of pyridine nucleotides and tumor suppressor proteins p53 and p73, and a decrease in apoptosis. The decrease in apoptosis causes myelogenous hyperplasia in NQO1-null mice. These results demonstrate that NQO1 acts as an endogenous factor in the protection against myelogenous hyperplasia. This is significant because 2-4% of human individuals without known abnormalities, and >25% of individuals with benzene poisoning and acute myelogenic leukemia are homozygous for a mutant allele (P187S) of NQO1 and lack NQO1 protein/activity.

Adenoviral-mediated retinoblastoma 94 produces rapid telomere erosion, chromosomal crisis, and caspase-dependent apoptosis in bladder cancer and immortalized human urothelial cells but not in normal urothelial cells.

Retinoblastoma (RB)94, which lacks the NH(2)-terminal 112 amino acid residues of the full-length RB protein (RB110), is a more potent tumor and growth suppressor than RB110. In this study, Ad-RB94, but not Ad-RB110, produced marked growth inhibition, cytotoxicity, caspase-dependent apoptosis, and G(2)-M block in the human RB-negative, telomerase-positive bladder cancer cell line UM-UC14. This effect was completely inhibited by pretreatment with caspase inhibitors (P < 0.0001). Similar results were seen in RB-positive and other RB-negative bladder cancer cell lines. Ad-RB94 produced rapid telomere length shortening and loss of telomere signal, which was associated with polyploidy and chromosomal aberrations (P < 0.001). Ad-RB94, however, showed no cytotoxicity to telomerase-negative human normal urothelium cells but was highly cytotoxic to telomerase-positive human E6 and E7 immortalized urothelial cells (P < 0.0001). In addition, telomerase-negative cells, which maintain their telomere length through an alternative lengthening of telomeres DNA recombination pathway, showed no cytotoxicity to RB94. These results suggest that the induction of rapid telomere erosion and chromosomal crisis by RB94 in telomerase-positive cancer and in telomerase-expressing immortalized human cells is a major factor in its selective and potent tumor suppression and cytotoxic activity. The lack of cytotoxicity to normal cells should also provide a high therapeutic index when used in gene therapy protocols for the treatment of bladder and other cancers.

Tumor-specific low molecular weight forms of cyclin E induce genomic instability and resistance to p21, p27, and antiestrogens in breast cancer.

The deregulated expression of cyclin E as measured by the overexpression of its low molecular weight (LMW) isoforms is a powerful predictor of poor outcome in patients with breast cancer. The mechanism by which these LMW forms give tumor cells a growth advantage is not known and is the subject of this article. In this article, we provide the pathobiological mechanisms of how these LMW forms are involved in disease progression. Specifically, we show that overexpression of the LMW forms of cyclin E but not the full-length form in MCF-7 results in (a) their hyperactivity because of increased affinity for cdk2 and resistance to inhibition by the cyclin-dependent kinase inhibitors p21 and p27, (b) resistance to the growth inhibiting effects of antiestrogens, and (c) chromosomal instability. Lastly, tumors from breast cancer patients overexpressing the LMW forms of cyclin E are polyploid in nature and are resistant to endocrine therapy. Collectively, the biochemical and functional differences between the full-length and the LMW isoforms of cyclin E provide a molecular mechanism for the poor clinical outcome observed in breast cancer patients harboring tumors expressing high levels of the LMW forms of cyclin E. These properties of the LMW forms cyclin E suggest that they are not just surrogate markers of poor outcome but bona fide mediators of aggressive disease and potential therapeutic targets for patients whose tumors overexpress these forms.

Prevention and Treatment of Cancer: Hypes and Hopes 6th International Translational Cancer Research Conference.

Cancer is primarily an "old-age" disease that has an "age-old" history. The overall incidence of cancer is much higher in Western countries, but is rapidly growing in Eastern countries perhaps due to change in life-style. Almost three million studies published to date indicate that cancer is a hyperproliferative disorder that arises from dysregulation of multiple cell signaling pathways. The cancer genome landscape indicates that approximately 140 genes and 12 cell signaling pathways drive almost all cancers. "Targeted therapy," a buzz word in cancer treatment for the past two decades, has provided antibodies, as well as small-molecule inhibitors. These therapies have been successful only in few instances. However, in most cases, minor increase in overall survival has been reported at the cost of huge expense. An alternative strategy is to prevent cancer or to diagnose and treat the disease at an early stage to gain survival benefits. Such interventions are also cost-effective. To address some of these issues, the 6th International Translational Cancer Research Conference was held during February 4-7th, 2016, in Ahmedabad, Gujarat, India; the homeland of Mahatma Gandhi. This conference was focused on utilizing multidisciplinary approaches for prevention and early treatment that would likely simultaneously or sequentially target many key pathways. Several distinguished speakers were invited from around the world. This article highlights primary features of this conference.

Understanding An Informed Public's Views On The Role Of Evidence In Making Health Care Decisions.

Policy makers and practitioners increasingly believe that medical evidence plays a critical role in improving care and health outcomes and lowering costs. However, public understanding of the role of evidence-based care may be different. Public deliberation is a process that convenes diverse citizens and has them learn about and consider ethical or values-based dilemmas and weigh alternative views. The Community Forum Deliberative Methods Demonstration project, sponsored by the Agency for Healthcare Research and Quality, obtained informed public views on the role of evidence in health care decisions through seventy-six deliberative groups involving 907 people overall, in the period August-November 2012. Although participants perceived evidence as being essential to high-quality care, they also believed that personal choice or clinical judgment could trump evidence. They viewed doctors as central figures in discussing evidence with patients and key arbiters of whether to follow evidence in individual cases. They found evidence of harm to individuals or the community to be more compelling than evidence of effectiveness. These findings indicate that increased public understanding of evidence can play an important role in advancing evidence-based care by helping create policies that better reflect the needs and values of the public.

Human Dkk-1, a gene encoding a Wnt antagonist, responds to DNA damage and its overexpression sensitizes brain tumor cells to apoptosis following alkylation damage of DNA.

The human Dkk-1 (hDkk-1) gene, a transcriptional target of the p53 tumor suppressor, encodes a powerful inhibitor of the Wnt signaling pathway and regulates the spatial patterning/morphogenesis of the mammalian central nervous system. We investigated the p53-related functions of the hDkk-1 gene by studying its response to DNA damage and its modulation of apoptosis in human glioma cells. Various chemotherapeutic and other agents that induce DNA adducts and compromise its integrity (1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), cisplatin, H(2)O(2) and UV rays) enhanced the expression of hDkk-1 significantly. The damage-induced increase in hDkk-1 mRNA levels occurred in many human tumor cell lines, irrespective of their p53 gene status. The human glioblastoma cell line, U87MG, which had undetectable hDkk-1 expression, was engineered to express moderate levels of the hDkk protein by stable transfection. The engineered cells did not show any morphological changes, but underwent marked apoptosis after ceramide treatment. Further, the DNA cross-linking drugs BCNU and cisplatin, but not the microtubule poison vincristine, induced significant cell death in U87MG/hDkk cells, and this was accompanied by altered Bcl-2/Bax expression and a reduction in the amount of telomere DNA as visualized by fluorescence in situ hybridization. These results show that hDkk-1 is a pro-apoptotic gene and suggest that it may play important roles in linking the oncogenic Wnt and p53 tumor suppressor pathways.