Common activities and predictive gene signature identified for genetic hypomorphs of TP53.

Missense mutations that inactivate p53 occur commonly in cancer, and germline mutations in TP53 cause Li Fraumeni syndrome, which is associated with early-onset cancer. In addition, there are over two hundred germline missense variants of p53 that remain uncharacterized. In some cases, these germline variants have been shown to encode lesser-functioning, or hypomorphic, p53 protein, and these alleles are associated with increased cancer risk in humans and mouse models. However, most hypomorphic p53 variants remain un- or mis-classified in clinical genetics databases. There thus exists a significant need to better understand the behavior of p53 hypomorphs and to develop a functional assay that can distinguish hypomorphs from wild-type p53 or benign variants. We report the surprising finding that two different African-centric genetic hypomorphs of p53 that occur in distinct functional domains of the protein share common activities. Specifically, the Pro47Ser variant, located in the transactivation domain, and the Tyr107His variant, located in the DNA binding domain, both share increased propensity to misfold into a conformation specific for mutant, misfolded p53. Additionally, cells and tissues containing these hypomorphic variants show increased NF-κB activity. We identify a common gene expression signature from unstressed lymphocyte cell lines that is shared between multiple germline hypomorphic variants of TP53, and which successfully distinguishes wild-type p53 and a benign variant from lesser-functioning hypomorphic p53 variants. Our findings will allow us to better understand the contribution of p53 hypomorphs to disease risk and should help better inform cancer risk in the carriers of p53 variants.

PLTP is a p53 target gene with roles in cancer growth suppression and ferroptosis.

The tumor suppressor protein p53 suppresses cancer by regulating processes such as apoptosis, cell cycle arrest, senescence, and ferroptosis, which is an iron-mediated and lipid peroxide-induced cell death pathway. Whereas numerous p53 target genes have been identified, only a few appear to be critical for the suppression of tumor growth. Additionally, while ferroptosis is clearly implicated in tumor suppression by p53, few p53 target genes with roles in ferroptosis have been identified. We have previously studied germline missense p53 variants that are hypomorphic or display reduced activity. These hypomorphic variants are associated with increased risk for cancer, but they retain the majority of p53 transcriptional function; as such, study of the transcriptional targets of these hypomorphs has the potential to reveal the identity of other genes important for p53-mediated tumor suppression. Here, using RNA-seq in lymphoblastoid cell lines, we identify PLTP (phospholipid transfer protein) as a p53 target gene that shows impaired transactivation by three different cancer-associated p53 hypomorphs: P47S (Pro47Ser, rs1800371), Y107H (Tyr107His, rs368771578), and G334R (Gly334Arg, rs78378222). We show that enforced expression of PLTP potently suppresses colony formation in human tumor cell lines. We also demonstrate that PLTP regulates the sensitivity of cells to ferroptosis. Taken together, our findings reveal PLTP to be a p53 target gene that is extremely sensitive to p53 transcriptional function and which has roles in growth suppression and ferroptosis.

GSK3ß-SCFFBXW7α mediated phosphorylation and ubiquitination of IRF1 are required for its transcription-dependent turnover.

IRF1 (Interferon Regulatory Factor-1) is the prototype of the IRF family of DNA binding transcription factors. IRF1 protein expression is regulated by transient up-regulation in response to external stimuli followed by rapid degradation via the ubiquitin-proteasome system. Here we report that DNA bound IRF1 turnover is promoted by GSK3ß (Glycogen Synthase Kinase 3ß) via phosphorylation of the T181 residue which generates a phosphodegron for the SCF (Skp-Cul-Fbox) ubiquitin E3-ligase receptor protein Fbxw7α (F-box/WD40 7). This regulated turnover is essential for IRF1 activity, as mutation of T181 results in an improperly stabilized protein that accumulates at target promoters but fails to induce RNA-Pol-II elongation and subsequent transcription of target genes. Consequently, the anti-proliferative activity of IRF1 is lost in cell lines expressing T181A mutant. Further, cell lines with dysfunctional Fbxw7 are less sensitive to IRF1 overexpression, suggesting an important co-activator function for this ligase complex. As T181 phosphorylation requires both DNA binding and RNA-Pol-II elongation, we propose that this event acts to clear 'spent' molecules of IRF1 from transcriptionally engaged target promoters.

Breakpoint analysis of transcriptional and genomic profiles uncovers novel gene fusions spanning multiple human cancer types.

Gene fusions, like BCR/ABL1 in chronic myelogenous leukemia, have long been recognized in hematologic and mesenchymal malignancies. The recent finding of gene fusions in prostate and lung cancers has motivated the search for pathogenic gene fusions in other malignancies. Here, we developed a "breakpoint analysis" pipeline to discover candidate gene fusions by tell-tale transcript level or genomic DNA copy number transitions occurring within genes. Mining data from 974 diverse cancer samples, we identified 198 candidate fusions involving annotated cancer genes. From these, we validated and further characterized novel gene fusions involving ROS1 tyrosine kinase in angiosarcoma (CEP85L/ROS1), SLC1A2 glutamate transporter in colon cancer (APIP/SLC1A2), RAF1 kinase in pancreatic cancer (ATG7/RAF1) and anaplastic astrocytoma (BCL6/RAF1), EWSR1 in melanoma (EWSR1/CREM), CDK6 kinase in T-cell acute lymphoblastic leukemia (FAM133B/CDK6), and CLTC in breast cancer (CLTC/VMP1). Notably, while these fusions involved known cancer genes, all occurred with novel fusion partners and in previously unreported cancer types. Moreover, several constituted druggable targets (including kinases), with therapeutic implications for their respective malignancies. Lastly, breakpoint analysis identified new cell line models for known rearrangements, including EGFRvIII and FIP1L1/PDGFRA. Taken together, we provide a robust approach for gene fusion discovery, and our results highlight a more widespread role of fusion genes in cancer pathogenesis.

Quality of Life Improvements with Biologic Initiation Among Subspecialist-Treated US Patients with Severe Asthma.

Purpose: Patients living with severe asthma (SA) experience multiple health-related quality of life (HRQoL) impairments. This study examined HRQoL changes after biologic treatment initiation among a large, real-world cohort of patients with SA. Patients and methods: CHRONICLE is an ongoing observational study of subspecialist-treated adults with SA who receive biologics or maintenance systemic corticosteroids or are uncontrolled on high-dosage inhaled corticosteroids with additional controllers. Patients enrolled February 2018-February 2023 were asked to complete the St. George's Respiratory Questionnaire (SGRQ) every 6 months (total score range of 0-100 [0=best possible health], meaningful change threshold is a 4-unit reduction in the total score). Changes in SGRQ responses from 6 months before initiation to 12 to 18 months after initiation were summarized. Results: A total of 76 patients completed the SGRQ 0 to 6 months before and 12 to 18 months after biologic initiation. The mean (SD) SGRQ total score decreased from 52.2 (20.6) to 41.9 (23.8), with improvement across the symptoms (-14.5), activity (-11.0), and impacts (-8.3) components. For specific impairments reported by ≥50% of patients before biologic initiation, fewer reported each impairment after biologic initiation; the largest reductions were for "Questions about what activities usually make you feel short of breath these days [Walking outside on level ground]" (67% to 43%), "Questions about other effects that your respiratory problems may have on you these days [I feel that I am not in control of my respiratory problems]" (55% to 34%), and "Questions about your cough and shortness of breath these days [My coughing or breathing disturbs my sleep]" (63% to 45%). Conclusion: In this real-world cohort of adults with SA, biologic initiation was associated with meaningful improvements in asthma-related HRQoL. These data provide further insight into the burden SA places on patients and the benefits of biologic treatment.

Implementing buprenorphine prolonged-release injection using a health at the margins approach for transactional sex-workers.

Background: Access to prescribed interventions and retention in treatment services are associated with improved health outcomes and reduced premature mortality rates for people living with opioid use disorder (OUD). In Leeds, transactional sex-workers frequently cycled in and out of treatment for OUD such that they never reached a level of engagement that permitted opportunities to meet their healthcare or housing needs. Barriers to accessing care provision include an itinerant lifestyle, difficulties with travel at unpredictable hours, impacting upon adherence to medication regimens including daily supervised consumption. Objectives: To use a co-produced, "health at the margins" approach, to reach the sex-working population in Leeds, and support informed choices about the potential to receive buprenorphine prolonged-release injection (BPRI) as a treatment option for OUD. Methods: BPRI was introduced using a theory of change model and improvements in sex-worker care delivery was reviewed. Strategies included buprenorphine micro-induction, shared decision-making, collaborative multi-agency working and supporting a strengths-based and trauma-informed approach. Results: Benefits of BPRI included removal of the need for daily pharmacy visits, reducing the risk of diversion, improved medication adherence, stability and engagement with treatment and supportive services. Conclusion: BPRI may offer an additional option for pharmacological interventions for people with OUD where there may be increased barriers to accessing treatment for example due to sex-working. Strategies for effective BPRI include micro-induction, shared decision-making, collaborative multi-agency working and supporting a strengths-based approach.

An African-Specific Variant of TP53 Reveals PADI4 as a Regulator of p53-Mediated Tumor Suppression.

TP53 is the most frequently mutated gene in cancer, yet key target genes for p53-mediated tumor suppression remain unidentified. Here, we characterize a rare, African-specific germline variant of TP53 in the DNA-binding domain Tyr107His (Y107H). Nuclear magnetic resonance and crystal structures reveal that Y107H is structurally similar to wild-type p53. Consistent with this, we find that Y107H can suppress tumor colony formation and is impaired for the transactivation of only a small subset of p53 target genes; this includes the epigenetic modifier PADI4, which deiminates arginine to the nonnatural amino acid citrulline. Surprisingly, we show that Y107H mice develop spontaneous cancers and metastases and that Y107H shows impaired tumor suppression in two other models. We show that PADI4 is itself tumor suppressive and that it requires an intact immune system for tumor suppression. We identify a p53-PADI4 gene signature that is predictive of survival and the efficacy of immune-checkpoint inhibitors. SIGNIFICANCE: We analyze the African-centric Y107H hypomorphic variant and show that it confers increased cancer risk; we use Y107H in order to identify PADI4 as a key tumor-suppressive p53 target gene that contributes to an immune modulation signature and that is predictive of cancer survival and the success of immunotherapy. See related commentary by Bhatta and Cooks, p. 1518. This article is highlighted in the In This Issue feature, p. 1501.

Tumor-selective action of HDAC inhibitors involves TRAIL induction in acute myeloid leukemia cells.

Chromatin is a dynamic macromolecular structure epigenetically modified to regulate specific gene expression. Altered chromatin function can lead to aberrant expression of growth regulators and may, ultimately, cause cancer. That many human diseases have epigenetic etiology has stimulated the development of 'epigenetic' therapies. Inhibitors of histone deacetylases (HDACIs) induce proliferation arrest, maturation and apoptosis of cancer cells, but not normal cells, in vitro and in vivo, and are currently being tested in clinical trials. We investigated the mechanism(s) underlying this tumor selectivity. We report that HDACIs induce, in addition to p21, expression of TRAIL (Apo2L, TNFSF10) by directly activating the TNFSF10 promoter, thereby triggering tumor-selective death signaling in acute myeloid leukemia (AML) cells and the blasts of individuals with AML. RNA interference revealed that the induction of p21, TRAIL and differentiation are separable activities of HDACIs. HDACIs induced proliferation arrest, TRAIL-mediated apoptosis and suppression of AML blast clonogenicity irrespective of French-American-British (FAB) classification status, karyotype and immunophenotype. No apoptosis was seen in normal CD34(+) progenitor cells. Our results identify TRAIL as a mediator of the anticancer action of HDACIs.

A ChIP-chip approach reveals a novel role for transcription factor IRF1 in the DNA damage response.

IRF1 is a transcription factor that regulates key processes in the immune system and in tumour suppression. To gain further insight into IRF1's role in these processes, we searched for new target genes by performing chromatin immunoprecipitation coupled to a CpG island microarray (ChIP-chip). Using this approach we identified 202 new IRF1-binding sites with high confidence. Functional categorization of the target genes revealed a surprising cadre of new roles that can be linked to IRF1. One of the major functional categories was the DNA damage response pathway. In order to further validate our findings, we show that IRF1 can regulate the mRNA expression of a number of the DNA damage response genes in our list. In particular, we demonstrate that the mRNA and protein levels of the DNA repair protein BRIP1 [Fanconi anemia gene J (FANC J)] are upregulated after IRF1 over-expression. We also demonstrate that knockdown of IRF1 by siRNA results in loss of BRIP1 expression, abrogation of BRIP1 foci after DNA interstrand crosslink (ICL) damage and hypersensitivity to the DNA crosslinking agent, melphalan; a characteristic phenotype of FANC J cells. Taken together, our data provides a more complete understanding of the regulatory networks controlled by IRF1 and reveals a novel role for IRF1 in regulating the ICL DNA damage response.

Using the QI Maturity Tool - Modified Ontario Version to assess the state of QI maturity in Ontario's public health units.

BACKGROUND: Implementation of quality improvement (QI) practices varies considerably among public health units (PHUs) in Ontario. With the emphasis on continuous quality improvement (CQI) in the revised Ontario Public Health Standards (OPHS), there is a need to understand the level of QI maturity in Ontario's PHUs. The objective of this research was to establish a baseline understanding of QI maturity in Ontario's PHUs. METHODS: The QI Maturity Tool - Modified Ontario Version was used to assess the state of QI maturity in 34 PHUs across Ontario. QI maturity was assessed through 23 questions across three dimensions: QI Organizational Culture; QI Capacity and Competency; and QI Perceived Value. QI maturity scores were classified into five stages: Beginning; Emerging; Progressing; Achieving; and Excelling. QI maturity scores were calculated for each of the 34 participating PHUs to determine their stage of QI maturity. Each PHU's score was then used to determine the provincial average for QI maturity. Participants were also asked to answer three questions related to core CQI organizational structures. RESULTS: Across the 34 PHUs, 3503 staff participated in the survey. A review of individual PHU scores indicates that Ontario's PHUs are at varying stages of QI maturity. The average QI maturity score of 4.94 for the 34 participating PHUs places the provincial average in the "Emerging" stage of QI maturity. By QI dimensions, the participating PHUs scored in the "Emerging" stage for QI Organizational Culture (5.09), the "Beginning" stage for QI Competency and Capacity (4.58), and the "Achieving" stage for QI Perceived Value (6.00). CONCLUSION: There is an urgent need for Ontario's PHUs to progress to higher stages of QI maturity. Participants place a high value on QI, but collectively are at less "mature" stages of QI in relation to QI organizational culture and the competency and capacity to engage in QI activities. PHUs should leverage the value that staff place on QI to foster the development of a culture of QI and provide staff with relevant knowledge and skills to engage in QI activities.

Targeting monoamine oxidase A-regulated tumor-associated macrophage polarization for cancer immunotherapy.

Targeting tumor-associated macrophages (TAMs) is a promising strategy to modify the immunosuppressive tumor microenvironment and improve cancer immunotherapy. Monoamine oxidase A (MAO-A) is an enzyme best known for its function in the brain; small molecule MAO inhibitors (MAOIs) are clinically used for treating neurological disorders. Here we observe MAO-A induction in mouse and human TAMs. MAO-A-deficient mice exhibit decreased TAM immunosuppressive functions corresponding with enhanced antitumor immunity. MAOI treatment induces TAM reprogramming and suppresses tumor growth in preclinical mouse syngeneic and human xenograft tumor models. Combining MAOI and anti-PD-1 treatments results in synergistic tumor suppression. Clinical data correlation studies associate high intratumoral MAOA expression with poor patient survival in a broad range of cancers. We further demonstrate that MAO-A promotes TAM immunosuppressive polarization via upregulating oxidative stress. Together, these data identify MAO-A as a critical regulator of TAMs and support repurposing MAOIs for TAM reprogramming to improve cancer immunotherapy.

Targeting monoamine oxidase A for T cell-based cancer immunotherapy.

Monoamine oxidase A (MAO-A) is an enzyme best known for its function in the brain, where it breaks down neurotransmitters and thereby influences mood and behavior. Small-molecule MAO inhibitors (MAOIs) have been developed and are clinically used for treating depression and other neurological disorders. However, the involvement of MAO-A in antitumor immunity has not been reported. Here, we observed induction of the Maoa gene in tumor-infiltrating immune cells. Maoa knockout mice exhibited enhanced antitumor T cell immunity and suppressed tumor growth. MAOI treatment significantly suppressed tumor growth in preclinical mouse syngeneic and human xenograft tumor models in a T cell-dependent manner. Combining MAOI and anti-PD-1 treatments generated synergistic tumor suppression effects. Clinical data correlation studies associated intratumoral MAOA expression with T cell dysfunction and decreased patient survival in a broad range of cancers. We further demonstrated that MAO-A restrains antitumor T cell immunity through controlling intratumoral T cell autocrine serotonin signaling. Together, these data identify MAO-A as an immune checkpoint and support repurposing MAOI antidepressants for cancer immunotherapy.

Reducing red blood cell transfusion in orthopedic and cardiac surgeries with Antifibrinolytics: A laboratory medicine best practice systematic review and meta-analysis.

OBJECTIVES: To evaluate the effectiveness of antifibrinolytics tranexamic acid (TA), ε-aminocaproic acid (EACA), and aprotinin to decrease overuse of red blood cell transfusions in adult surgical and non-surgical patients. METHODS: This review followed the Centers for Disease Control and Prevention (CDC) Laboratory Medicine Best Practice (LMBP™) Systematic Review (A-6) method. Eligible studies were assessed for evidence of effectiveness of TA or EACA in reducing the number of patients transfused or the number of whole blood transfusions. RESULTS: Seventy-two articles met LMBP™ inclusion criteria. Fifty-six studies assessed Topical, Intra-articular Injection, or Intravenous TA, 4 studied EACA, and 12 studied the effectiveness of aprotinin. The overall strength of the body of evidence of effectiveness for each of these practices was rated as high. CONCLUSION: LMBP™ recommends the use of topical, intra-articular injection, or intravenous tranexamic acid and the use of ε-aminocaproic acid for reducing overuse of red blood cell transfusion.

Anemia Management and Audit Feedback Practices for Reducing Overuse of RBC Transfusion: A Laboratory Medicine Best Practice Systematic Review and Meta-Analysis.

Objectives: To evaluate the effectiveness of anemia management and audit with feedback practices in reducing overuse of RBC transfusion. Methods: This review follows the Centers for Disease Control and Prevention's Laboratory Medicine Best Practice Systematic Review (A-6) method. We searched the literature and solicited unpublished studies on practices to reduce overuse of RBC transfusions as measured by reductions in units transfused and proportion of patients transfused. Results: Thirteen studies on preoperative anemia management and three studies on audit feedback practices met inclusion criteria. Strength of evidence was high to moderate for reducing the number of units and proportion of patients transfused. Conclusions: Preoperative anemia management reduces the proportion of patients transfused and units of RBCs transfused. Audit with feedback across cases, physicians, and/or service areas, as part of a continuous quality improvement practice, reduces the proportion of patients and units of RBCs transfused.

Restrictive Transfusion Strategy and Clinical Decision Support Practices for Reducing RBC Transfusion Overuse.

OBJECTIVES: Assess support for the effectiveness of two separate practices, restrictive transfusion strategy and computerized physician order entry/clinical decision support (CPOE/CDS) tools, in decreasing RBC transfusions in adult surgical and nonsurgical patients. METHODS: Following the Centers for Disease Control and Prevention Laboratory Medicine Best Practice (LMBP) Systematic Review (A-6) method, studies were assessed for quality and evidence of effectiveness in reducing the percentage of patients transfused and/or units of blood transfused. RESULTS: Twenty-five studies on restrictive transfusion practice and seven studies on CPOE/CDS practice met LMBP inclusion criteria. The overall strength of the body of evidence of effectiveness for restrictive transfusion strategy and CPOE/CDS was rated as high. CONCLUSIONS: Based on these procedures, adherence to an institutional restrictive transfusion strategy and use of CPOE/CDS tools for hemoglobin alerts or reminders of the institution's restrictive transfusion policies are effective in reducing RBC transfusion overuse.

Creatine uptake regulates CD8 T cell antitumor immunity.

T cells demand massive energy to combat cancer; however, the metabolic regulators controlling antitumor T cell immunity have just begun to be unveiled. When studying nutrient usage of tumor-infiltrating immune cells in mice, we detected a sharp increase of the expression of a CrT (Slc6a8) gene, which encodes a surface transporter controlling the uptake of creatine into a cell. Using CrT knockout mice, we showed that creatine uptake deficiency severely impaired antitumor T cell immunity. Supplementing creatine to WT mice significantly suppressed tumor growth in multiple mouse tumor models, and the combination of creatine supplementation with a PD-1/PD-L1 blockade treatment showed synergistic tumor suppression efficacy. We further demonstrated that creatine acts as a "molecular battery" conserving bioenergy to power T cell activities. Therefore, our results have identified creatine as an important metabolic regulator controlling antitumor T cell immunity, underscoring the potential of creatine supplementation to improve T cell-based cancer immunotherapies.

Acute myeloid leukemia: therapeutic impact of epigenetic drugs.

Acute myeloid leukemia (AML) is not a single disease but a group of malignancies in which the clonal expansion of various types of hematopoietic precursor cells in the bone marrow leads to perturbation of the delicate balance between self-renewal and differentiation that is characteristic of normal hematopoiesis. An increasing number of genetic aberrations, such as chromosomal translocations that alter the function of transcription regulatory factors, has been identified as the cause of AML and shown to act by deregulating gene programming at both the genetic and epigenetic level. While the genetic aberrations occurring in acute myeloid leukemia are fairly well understood, we have only recently become aware of the epigenetic deregulation associated with leukemia, in particular with myeloid leukemias. The deposition of epigenetic "marks" on chromatin - post-translational modifications of nucleosomal proteins and methylation of particular DNA sequences - is accomplished by enzymes, which are often embedded in multi-subunit "machineries" that have acquired aberrant functionalities during leukemogenesis. These enzymes are targets for so-called "epi-drugs". Indeed, recent results indicate that epi-drugs may constitute an entirely novel type of anti-cancer drugs with unanticipated potential. Proof-of-principle comes from studies with histone deacetylase inhibitors, promising novel anti-cancer drugs. In this review we focus on the epigenetic mechanisms associated with acute myeloid leukemogenesis and discuss the therapeutic potential of epigenetic modulators such as histone deacetylase and DNA methyltransferase inhibitors.

A novel sensory nerve conduction study technique to evaluate the sural nerve from the forefoot to the knee.

PURPOSE: Length-dependent polyneuropathy is common. Current electrophysiological methods cannot assess sensory nerve function proximal to the distal calf, limiting their utility in the quantification of severity of length-dependent polyneuropathy. METHODS: The authors developed a novel electrophysiological approach for distal to proximal assessment of the sural nerve between the forefoot and the knee and tested it on 63 healthy young, middle-aged, and old adults. RESULTS: It was feasible to elicit sensory nerve action potentials in the forefoot, ankle, and knee segments of the sural nerve in all subjects. Intraobserver (r = 0.87) and interobserver (r = 0.87) reliability were high. Sensory nerve action potential amplitudes were greatest at the ankle, followed by the knee and forefoot. Sensory nerve action potential amplitudes in the forefoot and ankle were significantly smaller in the old age group (>60 years) compared with the young age group (20-39 years) (P < 0.05). In contrast, neither age nor gender had a significant impact on sensory nerve action potential conduction velocities. CONCLUSIONS: The authors demonstrated that reliable electrophysiological recordings of the sural nerve as proximal as the knee are feasible. This novel technique may be useful in patients with length-dependent polyneuropathy to monitor progression and to evaluate treatment response.

Integrative Genomics Implicates EGFR as a Downstream Mediator in NKX2-1 Amplified Non-Small Cell Lung Cancer.

NKX2-1, encoding a homeobox transcription factor, is amplified in approximately 15% of non-small cell lung cancers (NSCLC), where it is thought to drive cancer cell proliferation and survival. However, its mechanism of action remains largely unknown. To identify relevant downstream transcriptional targets, here we carried out a combined NKX2-1 transcriptome (NKX2-1 knockdown followed by RNAseq) and cistrome (NKX2-1 binding sites by ChIPseq) analysis in four NKX2-1-amplified human NSCLC cell lines. While NKX2-1 regulated genes differed among the four cell lines assayed, cell proliferation emerged as a common theme. Moreover, in 3 of the 4 cell lines, epidermal growth factor receptor (EGFR) was among the top NKX2-1 upregulated targets, which we confirmed at the protein level by western blot. Interestingly, EGFR knockdown led to upregulation of NKX2-1, suggesting a negative feedback loop. Consistent with this finding, combined knockdown of NKX2-1 and EGFR in NCI-H1819 lung cancer cells reduced cell proliferation (as well as MAP-kinase and PI3-kinase signaling) more than knockdown of either alone. Likewise, NKX2-1 knockdown enhanced the growth-inhibitory effect of the EGFR-inhibitor erlotinib. Taken together, our findings implicate EGFR as a downstream effector of NKX2-1 in NKX2-1 amplified NSCLC, with possible clinical implications, and provide a rich dataset for investigating additional mediators of NKX2-1 driven oncogenesis.

Retinoids: potential in cancer prevention and therapy.

Retinoids (derivatives of vitamin A) are signalling molecules that play important roles in cell growth, differentiation and death. Retinoids act through two types of receptors - retinoic acid receptors (RAR alpha, RAR beta and RAR gamma) and retinoid X receptors (RXR alpha, RXR beta and RXR gamma) - which themselves act as ligand-dependent transcription factors. Retinoids are of special interest in cancer research owing to their antiproliferative and cancer-preventative properties. They have been used successfully to cure acute promyelocytic leukaemia (APL) and can suppress carcinogenesis in a variety of tissue types (e.g. skin, lung, breast and oral cancers). Extensive research efforts have been dedicated to elucidating the molecular and cellular networks that are induced by retinoids, and this has recently yielded novel insights into how retinoids can both prevent and combat cancer.