New directions in cancer and aging: State of the science and recommendations to improve the quality of evidence on the intersection of aging with cancer control.

BACKGROUND: The global population of older cancer survivors is growing. However, the intersections of aging-related health risks across the cancer control continuum are poorly understood, limiting the integration of aging into cancer control research and practice. The objective of this study was to review the state of science and provide future directions to improve the quality of evidence in 6 priority research areas in cancer and aging. METHODS: The authors identified priority research areas in cancer and aging through an evidence-based Research Jam process involving 32 investigators and trainees from multiple disciplines and research centers in aging and cancer; then, they conducted a narrative review of the state of the science and future directions to improve the quality of evidence in these research areas. Priority research areas were defined as those in which gaps in scientific evidence or clinical practice limit the health and well-being of older adults with cancer. RESULTS: Six priority research areas were identified: cognitive and physical functional outcomes of older cancer survivors, sampling issues in studies of older cancer survivors, risk and resilience across the lifespan, caregiver support and well-being, quality of care for older patients with cancer, and health disparities. Evidence in these areas could be improved through the incorporation of bias reduction techniques into longitudinal studies of older cancer survivors, novel data linkage, and improved representation of older adults in cancer research. CONCLUSIONS: The priority research areas and methodologies identified here may be used to guide interdisciplinary research and improve the quality of evidence on cancer and aging.

Mobilizing cross-disciplinary teams to advance translational research using design thinking methods.

Funding agencies are increasingly seeking team-based approaches to tackling complex research questions, but there is a need to mobilize translational teams and create shared visions and strategic action plans long before specific funding opportunities are considered or even released. This is particularly evident for teams who want to pursue large-scale grants, where cross-disciplinary synergy is often required. In response, we created Research Jams, which are engaging yet structured brainstorming sessions that bring together groups for the first time to collectively generate novel research ideas, critically map the future of initiatives, prioritize opportunities and next steps, and build community. Research Jams leveraged various aspects of design thinking, including divergence and convergence, visual thinking, and amplifying diversity. We piloted seven Research Jams for a collective 129 researchers, staff, and partners across 50 University of Michigan units and external organizations. Feedback was overwhelmingly positive, with the vast majority of survey respondents indicating that the sessions were helpful for surfacing shared ideas or visions and that opportunities emerged they would like to pursue. Research Jams were ideal for cross-disciplinary groups who wanted to collaboratively ideate and strategize around complex problems in translational research. Importantly, these models have the potential for implementation with groups in any disciplinary domain who want to spur collaborations to address challenging problems. Our ultimate goal is for Research Jams to be the first intervention within a comprehensive support pathway that extends from early brainstorming all the way to grant submission.

Differential modulation of the androgen receptor for prostate cancer therapy depends on the DNA response element.

Androgen receptor (AR) action is a hallmark of prostate cancer (PCa) with androgen deprivation being standard therapy. Yet, resistance arises and aberrant AR signaling promotes disease. We sought compounds that inhibited genes driving cancer but not normal growth and hypothesized that genes with consensus androgen response elements (cAREs) drive proliferation but genes with selective elements (sAREs) promote differentiation. In a high-throughput promoter-dependent drug screen, doxorubicin (dox) exhibited this ability, acting on DNA rather than AR. This dox effect was observed at low doses for multiple AR target genes in multiple PCa cell lines and also occurred in vivo. Transcriptomic analyses revealed that low dox downregulated cell cycle genes while high dox upregulated DNA damage response genes. In chromatin immunoprecipitation (ChIP) assays with low dox, AR binding to sARE-containing enhancers increased, whereas AR was lost from cAREs. Further, ChIP-seq analysis revealed a subset of genes for which AR binding in low dox increased at pre-existing sites that included sites for prostate-specific factors such as FOXA1. AR dependence on cofactors at sAREs may be the basis for differential modulation by dox that preserves expression of genes for survival but not cancer progression. Repurposing of dox may provide unique opportunities for PCa treatment.

Model for a university-based clinical research development infrastructure.

The Research Development Core (RDC) is housed within the Michigan Institute for Clinical & Health Research (MICHR) at the University of Michigan (U-M). Established in 2006, RDC provides no-cost, in-person consultations to help U-M investigators strengthen their grant proposals. RDC offers investigators feedback and critique on all aspects of their study design, plus partnerships, funding mechanisms, and future directions. This article describes RDC's model and provides data describing the success of its services.RDC is composed of a multidisciplinary team of professionals in grant development. It comprises two senior faculty codirectors from the U-M Medical School, two senior biostatisticians, outside faculty content experts, and RDC administrative staff. Investigators contact RDC to request a consultation and submit advance grant materials for review by the RDC team. During the consultation, investigators explain their project and identify challenges. The RDC team and additional experts offer feedback that is captured in meeting notes and provided to investigators. RDC commitments beyond the meetings are implemented and carefully tracked. Investigators may also request grant editing, budgeting, or proposal submission assistance. Investigators using RDC have been awarded $44.5 million since 2011.The demand for RDC consultations doubled from 2010 to 2011 and reached a high of 131 consultations in 2012. Investigator feedback has been positive: 80% reported that RDC had a strong impact on their proposal, and over 90% indicated that they would recommend RDC to colleagues. MICHR is committed to providing investigators with RDC services to better ensure strong grant applications and successful research careers.

Novel roles of prolactin and estrogens in breast cancer: resistance to chemotherapy.

Resistance to chemotherapy is a major complication in the treatment of advanced breast cancer. Estrogens and prolactin (PRL) are implicated in the pathogenesis of breast cancer but their roles in chemoresistance have been overlooked. A common feature to the two hormones is activation of their receptors by diverse compounds, which mimic or antagonize their actions. The PRL receptor is activated by lactogens (PRL, GH, or placental lactogen) originating from the pituitary, breast, adipose tissue, or the placenta. Estrogen receptors exist in multiple membrane-associated and cytoplasmic forms that can be activated by endogenous estrogens, man-made chemicals, and phytoestrogens. Here, we review evidence that low doses of PRL, estradiol (E(2)), and bisphenol A (BPA) antagonize multiple anticancer drugs that induce cell death by different mechanisms. Focusing on cisplatin, a DNA-damaging drug which is effective in the treatment of many cancer types but not breast cancer, we compare the abilities of PRL, E(2), and BPA to antagonize its cytotoxicity. Whereas PRL acts by activating the glutathione-S-transferase detoxification enzyme, E(2) and BPA act by inducing the antiapoptotic protein Bcl-2. The implications of these findings to patients undergoing chemotherapy are discussed.

Bisphenol A and estradiol are equipotent in antagonizing cisplatin-induced cytotoxicity in breast cancer cells.

Resistance to chemotherapy is a major problem facing breast cancer patients. Cisplatin, a highly effective DNA-damaging drug, has shown only little success in breast cancer treatment. We are reporting that low nanomolar doses of bisphenol A (BPA) or estradiol antagonize cisplatin cytotoxicity in breast cancer cells, with their effects not mediated via classical estrogen receptors. Although both compounds increase the expression of Bcl-2, a Bcl-2 inhibitor completely blocked the protective effects of BPA while only partially affecting those of estradiol. Blockade of BPA and E2 actions should sensitize ER-negative breast tumors to anti-cancer drugs and allow for the inclusion of cisplatin in treatment regimens.

Prolactin confers resistance against cisplatin in breast cancer cells by activating glutathione-S-transferase.

Resistance to chemotherapy is a major obstacle for successful treatment of breast cancer patients. Given that prolactin (PRL) acts as an anti-apoptotic/survival factor in the breast, we postulated that it antagonizes cytotoxicity by chemotherapeutic drugs. Treatment of breast cancer cells with PRL caused variable resistance to taxol, vinblastine, doxorubicin and cisplatin. PRL prevented cisplatin-induced G(2)/M cell cycle arrest and apoptosis. In the presence of PRL, significantly less cisplatin was bound to DNA, as determined by mass spectroscopy, and little DNA damage was seen by gamma-H2AX staining. PRL dramatically increased the activity of glutathione-S-transferase (GST), which sequesters cisplatin in the cytoplasm; this increase was abrogated by Jak and mitogen-activated protein kinase inhibitors. PRL upregulated the expression of the GSTmu, but not the pi, isozyme. A GST inhibitor abrogated antagonism of cisplatin cytotoxicity by PRL. In conclusion, PRL confers resistance against cisplatin by activating a detoxification enzyme, thereby reducing drug entry into the nucleus. These data provide a rational explanation for the ineffectiveness of cisplatin in breast cancer, which is characterized by high expression of both PRL and its receptor. Suppression of PRL production or blockade of its actions should benefit patients undergoing chemotherapy by allowing for lower drug doses and expanded drug options.

Treatment-dependent androgen receptor mutations in prostate cancer exploit multiple mechanisms to evade therapy.

Mutations in the androgen receptor (AR) that enable activation by antiandrogens occur in hormone-refractory prostate cancer, suggesting that mutant ARs are selected by treatment. To validate this hypothesis, we compared AR variants in metastases obtained by rapid autopsy of patients treated with flutamide or bicalutamide, or by excision of lymph node metastases from hormone-naïve patients. AR mutations occurred at low levels in all specimens, reflecting genetic heterogeneity of prostate cancer. Base changes recurring in multiple samples or multiple times per sample were considered putative selected mutations. Of 26 recurring missense mutations, most in the NH(2)-terminal domain (NTD) occurred in multiple tumors, whereas those in the ligand binding domain (LBD) were case specific. Hormone-naïve tumors had few recurring mutations and none in the LBD. Several AR variants were assessed for mechanisms that might underlie treatment resistance. Selection was evident for the promiscuous receptor AR-V716M, which dominated three metastases from one flutamide-treated patient. For the inactive cytoplasmically restricted splice variant AR23, coexpression with AR enhanced ligand response, supporting a decoy function. A novel NTD mutation, W435L, in a motif involved in intramolecular interaction influenced promoter-selective, cell-dependent transactivation. AR-E255K, mutated in a domain that interacts with an E3 ubiquitin ligase, led to increased protein stability and nuclear localization in the absence of ligand. Thus, treatment with antiandrogens selects for gain-of-function AR mutations with altered stability, promoter preference, or ligand specificity. These processes reveal multiple targets for effective therapies regardless of AR mutation.

Bisphenol A at low nanomolar doses confers chemoresistance in estrogen receptor-alpha-positive and -negative breast cancer cells.

BACKGROUND: Resistance to chemotherapy is a major problem facing breast cancer patients, and identifying potential contributors to chemoresistance is a critical area of research. Bisphenol A (BPA) has long been suspected to promote carcinogenesis, but the high doses of BPA used in many studies generated conflicting results. In addition, the mechanism by which BPA exerts its biological actions is unclear. Although estrogen has been shown to antagonize anticancer drugs, the role of BPA in chemoresistance has not been examined. OBJECTIVE: The objective of our study was to determine whether BPA at low nanomolar concentrations opposes the action of doxorubicin, cisplatin, and vinblastine in the estrogen receptor-alpha (ERalpha)-positive T47D and the ERalpha-negative MDA-MB-468 breast cancer cells. METHODS: We determined the responsiveness of cells to anticancer drugs and BPA using the 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide (MTT) cytotoxicity assay. Specific ERalpha and ERbeta inhibitors and real-time polymerase chain reaction were used to identify potential receptor(s) that mediate the actions of BPA. Expression of antiapoptotic proteins was assessed by Western blotting. RESULTS: BPA antagonizes the cytotoxicity of multiple chemotherapeutic agents in both ERalpha-positive and -negative breast cancer cells independent of the classical ERs. Both cell types express alternative ERs, including G-protein-coupled receptor 30 (GPR30) and members of the estrogen-related receptor family. Increased expression of antiapoptotic proteins is a potential mechanism by which BPA exerts its anticytotoxic effects. CONCLUSIONS: BPA at environmentally relevant doses reduces the efficacy of chemotherapeutic agents. These data provide considerable support to the accumulating evidence that BPA is hazardous to human health.

What can we learn from rodents about prolactin in humans?

Prolactin (PRL) is a 23-kDa protein hormone that binds to a single-span membrane receptor, a member of the cytokine receptor superfamily, and exerts its action via several interacting signaling pathways. PRL is a multifunctional hormone that affects multiple reproductive and metabolic functions and is also involved in tumorigenicity. In addition to being a classical pituitary hormone, PRL in humans is produced by many tissues throughout the body where it acts as a cytokine. The objective of this review is to compare and contrast multiple aspects of PRL, from structure to regulation, and from physiology to pathology in rats, mice, and humans. At each juncture, questions are raised whether, or to what extent, data from rodents are relevant to PRL homeostasis in humans. Most current knowledge on PRL has been obtained from studies with rats and, more recently, from the use of transgenic mice. Although this information is indispensable for understanding PRL in human health and disease, there is sufficient disparity in the control of the production, distribution, and physiological functions of PRL among these species to warrant careful and judicial extrapolation to humans.

LS14 cells: a model for chemoresistance in liposarcoma.

Liposarcoma, a malignancy of adipose tissue, is the most common soft tissue sarcoma. Patients whose primary tumor cannot be resected or those who have developed metastasis, have poor prognosis since liposarcomas are highly resistant to chemotherapy. We recently generated a spontaneously immortalized cell line, named LS14, from a patient with metastatic liposarcoma. Our goal was to compare the responsiveness of LS14 and SW872 liposarcoma cells to anti-cancer drugs and explore mechanisms of chemoresistance. Using complementary assays for cell viability and number we found that SW872 cells responded robustly to relatively low concentrations of doxorubicin, cisplatin and vinblastine. This reduction in cell viability was due to apoptosis, as evident by phosphatidylserine exposure and caspase 3 cleavage. In contrast, only a high dose of doxorubicin or combination therapy effectively reduced LS14 cell viability and induced apoptosis. LS14 cells showed a higher expression of Bcl-2 and Bcl-xL, but a lower expression of survivin and Bax, than SW872 cells, suggesting that anti-apoptotic proteins contribute to chemoresistance in LS14 cells. Although LS14 cells did not form colonies in soft agar, they generated large tumors and metastases in SCID mice, establishing their tumorigenicity in vivo. In conclusion, LS14 cells are much more resistant to chemotherapy than SW872 cells, making them an excellent model for exploring the efficacy and mechanism of action of anti-cancer drugs in liposarcomas.