The National Academies' Roundtable on Genomics and Precision Health: Where we have been and where we are heading.

The clinical application of genetics and genomics to advance precision health is one of the most dynamic and promising areas of medicine. In 2020, building on nearly 15 years of work, the Roundtable on Genomics and Precision Health of the National Academies of Sciences, Engineering, and Medicine undertook a strategic planning process to assess its strengths, consider the current challenges facing the field, and set out new goals for its future work. As a result, the Roundtable has updated its vision and mission and prioritized four major areas of inquiry-innovation, dialogue, equity, and adoption-while keeping true to its founding goal of providing a neutral convening space for the diversity of stakeholders in genomics and precision health. The Roundtable is unique for its breadth of membership and is committed to fostering a new era for precision health built on decades of expanding knowledge and the emergence of new technologies. To achieve its goals, the Roundtable seeks to broaden its membership's diversity and to engage with new audiences. Roundtable members explore how evidence-based discoveries in genomics could be adopted and used in innovative ways to better serve human health, how equitable access to genomic and precision health technologies can be ensured, and how the Roundtable and broader genomics and precision health community can communicate more effectively to inform the public regarding genomics and precision health. As a first principle, the Roundtable is working to support the overall goal that all people benefit from genomics for precision health.

Implementing Cancer Genomics in State Health Agencies: Mapping Activities to an Implementation Science Outcome Framework.

OBJECTIVE: To show how state health agencies can plan and evaluate activities to strengthen the evidence base for public health genomics, we mapped state cancer genomics activities to the Doyle et al. [Genet Med. 2018;20(9):995-1003] implementation science outcome framework. METHODS: We identified state health agency activities addressing hereditary breast and ovarian cancer and Lynch syndrome by reviewing project narratives from Centers for Disease Control and Prevention Cancer Genomics Program funding recipients, leading discussions with state health agencies, and conducting an environmental scan. RESULTS: State health agencies' cancer genomics activities included developing or adding to state surveillance systems, developing educational materials, bidirectional reporting, promoting health plan policy change, training providers, and promoting recommendations and standards. To address health disparities, programs have tracked group differences, developed culturally appropriate educational materials, and promoted access to services for underserved populations. CONCLUSION: State health agencies can use the Doyle et al. [Genet Med. 2018;20(9):995-1003] performance objectives and outcome measures to evaluate proposed and ongoing activities. By demonstrating whether activities result in improved outcomes, state health agencies can build the evidence for the implementation of cancer genomics activities.

Tumor priming by Apo2L/TRAIL reduces interstitial fluid pressure and enhances efficacy of liposomal gemcitabine in a patient derived xenograft tumor model.

Interstitial fluid pressure (IFP) is elevated in tumors and high IFP, a negative cancer prognosticator, is known to limit the uptake and efficacy of anti-tumor therapeutics. Approaches that alter the tumor microenvironment and enhance uptake of therapeutics are collectively referred to as tumor "priming". Here we show that the cytotoxic biological therapy Apo2L/TRAIL can prime the tumor microenvironment and significantly lower IFP in three different human tumor xenograft models (Colo205, MiaPaca-2 and a patient gastrointestinal adenocarcinoma tumor xenograft). We found that a single dose of Apo2L/TRAIL resulted in a wave of apoptosis which reached a maximum at 8h post-treatment. Apoptotic debris subsequently disappeared concurrent with an increase in macrophage infiltration. By 24h post-treatment, treated tumors appeared less condensed with widening of the stromal areas which increased at 48 and 72h. Analysis of tumor vasculature demonstrated a significant increase in overall vessel size at 48 and 72h although the number of vessels did not change. Notably, IFP was significantly reduced in these tumors by 48h after Apo2L/TRAIL treatment. Administration of gemcitabine at this time resulted in increased tumor uptake of both gemcitabine and liposomal gemcitabine and significantly improved anti-tumor efficacy of liposomal gemcitabine. These results suggest that Apo2L/TRAIL has a potential as a tumor priming agent and provides a rationale for developing a sequencing schema for combination therapy such that an initial dose of Apo2L/TRAIL would precede administration of gemcitabine or other therapies.

Isolated Hoxa9 overexpression predisposes to the development of lymphoid but not myeloid leukemia.

Hoxa9 is expressed in hematopoietic stem and progenitor cells, although this expression is usually diminished as these cells undergo differentiation. In addition, aberrant expression of Hoxa9 is strongly associated with both T cell and myeloid leukemia in mice and humans. Despite this strong association, enforced expression of Hoxa9 in murine bone marrow or thymus has only shown a modest ability to transform cells. To investigate this question, we used Vav regulatory elements to generate a transgenic mouse that targets Hoxa9 overexpression to all hematopoietic tissues. High-level expression of the Hoxa9 transgene in the hematopoietic compartment was associated with embryonic lethality, as no pups from founders that expressed high levels of the transgene were born live. However, offspring of an additional founder line, which expressed lower levels of Hoxa9, developed a precursor T cell lymphoblastic leukemia/lymphoma, accompanied by spontaneous Notch1 mutations. In contrast to most murine models of leukemia associated with Hoxa9 overexpression, the Vav-Hoxa9 mice did not overexpress other Hoxa cluster genes, mir196b (a microRNA that is embedded in the Hoxa locus), Meis1, or Pbx3. The Hoxa9 transgenic mouse reported in this study provides a suitable system for the study of Hoxa9 collaborators that drive myeloid and lymphoid malignant transformation.

Gene expression profiling and candidate gene resequencing identifies pathways and mutations important for malignant transformation caused by leukemogenic fusion genes.

NUP98-HOXD13 (NHD13) and CALM-AF10 (CA10) are oncogenic fusion proteins produced by recurrent chromosomal translocations in patients with acute myeloid leukemia (AML). Transgenic mice that express these fusions develop AML with a long latency and incomplete penetrance, suggesting that collaborating genetic events are required for leukemic transformation. We employed genetic techniques to identify both preleukemic abnormalities in healthy transgenic mice as well as collaborating events leading to leukemic transformation. Candidate gene resequencing revealed that 6 of 27 (22%) CA10 AMLs spontaneously acquired a Ras pathway mutation and 8 of 27 (30%) acquired an Flt3 mutation. Two CA10 AMLs acquired an Flt3 internal-tandem duplication, demonstrating that these mutations can be acquired in murine as well as human AML. Gene expression profiles revealed a marked upregulation of Hox genes, particularly Hoxa5, Hoxa9, and Hoxa10 in both NHD13 and CA10 mice. Furthermore, mir196b, which is embedded within the Hoxa locus, was overexpressed in both CA10 and NHD13 samples. In contrast, the Hox cofactors Meis1 and Pbx3 were differentially expressed; Meis1 was increased in CA10 AMLs but not NHD13 AMLs, whereas Pbx3 was consistently increased in NHD13 but not CA10 AMLs. Silencing of Pbx3 in NHD13 cells led to decreased proliferation, increased apoptosis, and decreased colony formation in vitro, suggesting a previously unexpected role for Pbx3 in leukemic transformation.

Enforced expression of Lin28b leads to impaired T-cell development, release of inflammatory cytokines, and peripheral T-cell lymphoma.

LIN28A and LIN28B, the mammalian homologs of lin-28, are implicated in malignant transformation in part because of their ability to promote degradation of the let-7 family of miRs. In the present study, we show that overexpression of Lin28b in vivo leads to an aggressive peripheral T-cell lymphoma (PTCL) characterized by widespread infiltration of parenchymal organs with malignant CD4(+) cells. Similar to patients with PTCL, Lin28b-transgenic mice show signs of inflammation such as eosinophilia, increased C-reactive protein, release of inflammatory cytokines, and pleural effusion. The PTCLs that develop in Lin28b mice are derived from activated T cells and show decreased let-7 expression, increased Il6 expression, activation of NF-κB, and infiltration of B cells, all resulting in an inflammatory microenvironment. In addition, LIN28B is overexpressed 7.5-fold in PTCL patient samples compared with activated CD4(+) cells. The results of the present study demonstrate for the first time that Lin28b can transform primary cells in vivo, identify a previously unsuspected link between Lin28b and PTCL, and provide a unique animal model for the study of PTCL biology and therapy.

Toward establishment of temperature thresholds for immunological impact of heat exposure in humans.

There is interest in understanding the health impact of thermal effects as a result of exposure of humans to radiofrequency/microwave (RF/MW) fields. Immune cells and responses are affected by modest changes in temperature and it is important to quantify these effects and establish safety thresholds similar to what has been done with other tissue targets. Since previous summaries of thresholds for thermal damage to normal tissues have not focused much attention to cells of the immune system, this summary highlights recent studies which demonstrate positive and some negative effects of temperature shifts on human immune cells. We emphasise literature reporting adverse immunological endpoints (such as cell damage, death and altered function) and provide the temperature at which these effects were noted. Whereas there have been many in vitro studies of adverse temperature effects on immune cells, there has been limited validation of these temperature effects in vivo. However, data from heat stress/stroke patients do provide some information regarding core temperatures (40°C) at which thermal damage to immunological processes can begin to occur. We conclude that there is considerable need for more quantitative time temperature assessments using relevant animal models, more complete kinetic analyses to determine how long immunological effects persist, and for analysis of whether frequency of exposure has impact on immune function. To date, no attempt to categorise effects by using cumulative thermal dose measurements (e.g. cumulative equivalent minutes at a given temperature) has been conducted for cells or tissues of the immune system, representing a major gap in this field.

Mouse models of myelodysplastic syndromes.

Three general approaches have been used to model myelodysplastic syndrome (MDS) in mice, including treatment with mutagens or carcinogens, xenotransplantation of human MDS cells, and genetic engineering of mouse hematopoietic cells. This article discusses the phenotypes observed in available mouse models for MDS with a concentration on a model that leads to aberrant expression of conserved homeobox genes that are important regulators of normal hematopoiesis. Using these models of MDS should allow a more complete understanding of the disease process and provide a platform for preclinical testing of therapeutic approaches.

Dissecting the role of hyperthermia in natural killer cell mediated anti-tumor responses.

The effects of hyperthermia on natural killer (NK) cell cytotoxicity against tumor cell targets are not yet fully understood. A more complete understanding of these effects could be important for maximizing the clinical benefits obtained by using hyperthermia for cancer therapy. Here, we summarize results in the literature regarding the effects of elevated temperatures on NK cells and our own recent data on the effects of fever-range temperatures. At treatment temperatures above 40 degrees C, (which is above the physiological body temperatures normally achieved during fever or exercise), both enhancing and inhibitory effects on cytotoxic activity of NK cells against tumor cells have been reported. Our own results have shown that fever-range thermal stress (using a temperature of 39.5 degrees C) enhances human NK cell cytotoxicity against tumor target cells. This effect requires function of the NKG2D receptor of NK cells, and is maximal when both NK and tumor cell targets are heated. Reported heat sensitive cellular targets affected by hyperthermia on tumor cells include heat shock proteins, MICA and MHC Class I. In NK cells, plasma membrane reorganization may occur after mild heat stress. We conclude this review by listing several unresolved questions that should be addressed for a more complete understanding of the molecular mechanisms which underlie the effects of thermal stress on the function of NK cells. Altogether, the available data indicate a strong potential for heat-induced enhancement of NK cell activity in mediating, at least in part, the improved clinical responses seen when hyperthermia is used in combination with other therapies.

The tetraspanin superfamily member NET-6 is a new tumor suppressor gene.

PURPOSE: NET-6 is a largely uncharacterized member of the tetraspanin superfamily. We have recently shown that its expression level was lowest in breast carcinomas with aggressive characteristics. We now describe the phenotypic and molecular changes induced in MDA-MB-231 breast carcinoma cells by ectopic NET-6 expression. METHODS: A GFP-NET-6 construct was transfected into very low expressing MDA-MB-231 cells. The subcellular distribution was studied by confocal microscopy. Cell proliferation in vitro was measured by MTT assay. Subcutaneous tumor formation in SCID mice was also studied. Other phenotypic parameters measured included growth in soft agar and extracellular matrix invasion. The effect of NET-6 transfection on the cell cycle was interrogated by flow cytometry. Deregulation of metalloproteinase expression was investigated by RT-PCR. Deregulation of proteins involved in apoptosis and cell cycle control was studied by Western blotting. RESULTS: Ectopic expression of NET-6 inhibited anchorage independent growth and invasion in a Boyden chamber assay. These effects were associated with downregulation of the matrix metalloproteinases MMP-1 and MMP-3. NET-6 had marked antiproliferative activity, both in vitro and in SCID mice. This effect was largely due to increased apoptosis. We identified upregulation of the pro-apoptotic molecules p53, bax, bak and caspase 3. CONCLUSIONS: Our data provide novel and compelling evidence that NET-6 is a potent new breast cancer suppressor gene.