Premalignant State Research Articles

Obesity and risk of monoclonal gammopathy of undetermined significance and progression to multiple myeloma: a population-based study.

All multiple myeloma (MM) cases are preceded by the premalignant state monoclonal gammopathy of undetermined significance (MGUS). Results from previous studies show a positive association between obesity and MM; however, the association between obesity and MGUS is controversial. The aims were to determine (1) if obesity is associated with an increased risk of MGUS and light-chain MGUS (LC-MGUS) and (2) whether obesity is associated with a higher risk of progression to MM and other lymphoproliferative (LP) diseases. Data from the population-based Age, Gene/Environment Susceptibility-Reykjavik Study (N = 5764) were used. We performed serum protein electrophoresis and serum free light-chain assay on all subjects to identify MGUS and LC-MGUS cases. We included 11 different measures on current and previous obesity in our analysis. Logistic regression and Cox proportional-hazard regression were used to analyze the associations. A total of 300 (5.2%) MGUS and 275 (4.8%) LC-MGUS cases were identified. During a median follow-up of 8 years, 18 had progressed to MM and 11 to other LP diseases. We found no association between the 11 obesity markers and MGUS or LC-MGUS (odds ratios 0.81 to 1.15 for all 11 variables in both conditions). Interestingly, we found that high midlife body mass index increased risk of progression to MM and other LP diseases (hazard ratio, 2.66; 95% confidence interval, 1.17-6.05). To conclude, obesity was not associated with MGUS. However, we found overweight/obesity to be a risk factor for progression from MGUS to MM and other LP diseases, suggesting that obesity plays a role in the transformation of MGUS to MM.

Status of Salivary Nitric Oxide Levels and Buccal Epithelial Cell DNA Damage in Potentially Malignant Disorders – A Biochemical Study

Oral cancer is a progressive, multistage disease in which changes in genetic structure and cellular morphology occur from the normal to the premalignant state and then to the malignant state. Nitric oxide (NO.) is an uncharged molecule with an unpaired electron. It is highly reactive and interacts with DNA molecules, resulting in DNA damage. Objective: To evaluate the salivary nitric oxide levels and buccal epithelial cell DNA damage in patients with potentially malignant oral disorders. Methods: The salivary nitric oxide levels and buccal epithelial cell DNA damage were estimated in 20 healthy individuals without oral lesions, in 20 subjects having smoking and/or tobacco chewing habits without oral lesions, and 20 patients with a potentially malignant oral disorder. Results: The salivary nitric oxide levels were significantly greater in the subjects with tobacco chewing and/or smoking habits without oral lesions than in the healthy controls. Similarly, the extent of DNA damage was higher in the subjects with potentially malignant disorders and in the subjects with tobacco chewing and/or smoking habits without oral lesions than in the healthy controls. Conclusion: The encouraging results of the present study indicated the potential involvement of nitric oxide in the pathogenesis of potentially malignant oral disorders.

Abstract 4388: Characterisation of molecular events across the colorectal cancer progression axis

Abstract Uniquely amongst the major tumor types, the premalignant state in colorectal cancer (CRC) is readily detectable and diagnosed. Indeed, a multi-step process of CRC genesis was defined by the seminal work of Vogelstein et al, who described the mutational events leading from adenoma to adenocarcinoma. In addition to genetic aberrations, recent evidence has highlighted the importance of the gut microbiome and associated inflammation in predicting CRC progression. To date however, these insights have not led to significant changes in the treatment paradigm because efforts continue to be focused on the later stages of disease. We believe CRC presents an exceptional opportunity for disease interception but to design effective interventional strategies, the exact sequence of molecular events underlying progression needs to be better defined and understood. To address these needs, we have assembled a clinically annotated sample database encompassing all stages of CRC (healthy colon, adjacent mucosa, adenomas, high-grade dysplasia, primary CRC and liver metastases), including samples from the conventional, microsatellite stable subtype, as well as from the serrated, microsatellite instable pathway. The progression status of each sample was characterized using standard pathology criteria. In addition, molecular progression was determined by targeted mutation profiling and targeted copy number profiling, as well as genome-wide expression profiling. This analysis confirms previous observations of early mutational events at the adenoma stage, including known tumor suppressor and oncogene driver mutations, e.g. KRAS G12 and G13 are mutated in 15% of the conventional adenomas but not in sessile serrated adenomas, as well as in 23% of the colorectal tumors. Copy number aberrations were observed at the adenoma and carcinoma stage, but with a lower prevalence then somatic mutations. Furthermore, genome wide expression analysis indicates that several pathways known to be affected in colorectal cancer are already disregulated at the adenoma stage. These pathways include Wnt signaling, mucosal barrier defects, bile acid metabolism, and several immune respons genes, again fingerpointing at the interplay between local inflammation, the microbiome, and epithelial events. In addition, we observed that while genetic events are very dissimilar between the serrated/MSI and conventional/MSS pathway, the transcriptional regulation has many similarities, indicating at a possibility at targeting these disease subtypes using the same therapeutics. These initial findings provide rational avenues to intercept CRC at the adenoma stage and efforts are now focused on exploring the added role of the colonic microbiota and immune system modulation. A more comprehensive and integrated view of the changes associated with disease initiation will lead to the identification of new paths for prevention, interception and cure. Citation Format: Joke Reumers, Liesbeth Van Wesenbeeck, Eric Ciamporcero, Gerald Chu, Stan Gaj, Emanuele Palescandolo, Carl Van Hove, Karin Verstraeten, Gary Borzillo, Dianna Wu, Pieter Peeters, Janine Arts. Characterisation of molecular events across the colorectal cancer progression axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4388. doi:10.1158/1538-7445.AM2017-4388

Hematopathological alterations of major tumor suppressor cascade, vital cell cycle inhibitors and hematopoietic niche components in experimental myelodysplasia

Myelodysplastic syndrome (MDS) is a poorly understood dreadful hematopoietic disorder that involves maturational defect and abnormalities in blood cell production leading to dysplastic changes and peripheral blood pancytopenia. The present work aims in establishing the mechanistic relationship of the expressional alterations of major tumor suppressor cascade, vital cell cycle inhibitors and hematopoietic microenvironmental components with the disease pathophysiologies. The study involves the development of N-N′ Ethylnitrosourea (ENU) induced mouse model of MDS, characterization of the disease with blood film and bone marrow smear studies, scanning electron microscopic observation, mitochondrial membrane potential determination, flowcytometric analysis of osteoblastic and vascular niche components along with the expressional study of cleaved caspase-3, PCNA, Chk-2, p53, Ndn, Gfi-1, Tie-2, Sdf-1, Gsk-3β, p18 and Myt-1 in the bone marrow compartment. Dysplastic features were found in peripheral blood of MDS mice which seemed to be the consequence of three marrow pathophysiological conditions viz; aberrant rise of cellular proliferation, increased apoptosis and crowding of abnormal blast population. Expressional decline of the p53 cascade involving Chk-2, p53, Ndn, Gfi-1 along with the downregulation of major cell cycle inhibitors seemed to be associated with the hyper-proliferative nature of bone marrow cells during MDS. Moreover the disruption of osteoblastic niche components added to the decreased hematopoietic quiescency. Increased marrow vascular niche components signified the pre-malignant state of MDS. Elevated cellular apoptosis and rise in the blast burden were also found to be associated with the p53 expression dependent collapsing of mitochondrial membrane potential and upregulation of Tie-2 respectively. The study established the mechanistic correlation between the alterations of the mentioned signaling components and hematopoietic anomalies during MDS which may be beneficial for the development of therapeutic strategies for the disease.

Id2 Collaborates with Id3 To Suppress Invariant NKT and Innate-like Tumors.

Inhibitor of DNA binding (Id) proteins, including Id1-4, are transcriptional regulators involved in promoting cell proliferation and survival in various cell types. Although upregulation of Id proteins is associated with a broad spectrum of tumors, recent studies have identified that Id3 plays a tumor-suppressor role in the development of Burkitt's lymphoma in humans and hepatosplenic T cell lymphomas in mice. In this article, we report rapid lymphoma development in Id2/Id3 double-knockout mice that is caused by unchecked expansion of invariant NKT (iNKT) cells or a unique subset of innate-like CD1d-independent T cells. These populations began to expand in neonatal mice and, upon malignant transformation, resulted in mortality between 3 and 11 mo of age. The malignant cells also gave rise to lymphomas upon transfer to Rag-deficient and wild-type hosts, reaffirming their inherent tumorigenic potential. Microarray analysis revealed a significantly modified program in these neonatal iNKT cells that ultimately led to their malignant transformation. The lymphoma cells demonstrated chromosome instability along with upregulation of several signaling pathways, including the cytokine-cytokine receptor interaction pathway, which can promote their expansion and migration. Dysregulation of genes with reported driver mutations and the NF-κB pathway were found to be shared between Id2/Id3 double-knockout lymphomas and human NKT tumors. Our work identifies a distinct premalignant state and multiple tumorigenic pathways caused by loss of function of Id2 and Id3. Thus, conditional deletion of Id2 and Id3 in developing T cells establishes a unique animal model for iNKT and relevant innate-like lymphomas.

Органосохраняющее лечение раннего рака прямой кишки

Aim of review. To generalize scientific data and to develop modern concept on the issue of diagnosis, staging and treatment of early rectal cancer. Summary. The world-wide issues of early rectal cancer are discussed in the review. Diagnostic methods and staging of the early cancer and premalignant states are discussed. Prospects of improvement of early rectal cancer treatment approach are outlined, advantages of the rectum-preserving techniques are justified. Conclusion. Early rectal cancer is rarely observed neoplasm that may be the main cause for diagnostic and staging difficulties. So far the choice of surgical method for early rectal cancer is a subject for discussion, at the same time the choice of method is determined not only by the tumor invasion depth, but also by the presence of risk factors for regional lymph node involvement.

Salivary Nitric Oxide Levels and Buccal Epithelial Cell DNA Damage in Oral Cancer - A Biochemical Study

Abstract Background: Cancer is the one of the common cause of mortality in developed and developing countries. Tobacco in any form is found to induce cancer formation. Oral cancer is a multistage process with progressive changes occurring in genetic and cellular morphology as the disease progresses from the normal to premalignant state and then to malignant state. Recent studies have emphasised that nitric oxide is a highly reactive molecule that interacts with DNA resulting in DNA damage.The objective of the present study was to evaluate the nitric oxide levels in the saliva and buccal epithelial cell DNA damage in patients with oral cancer. Material and methods: In this study nitric oxide levels in saliva and buccal epithelial cell DNA damage were estimated in 20 healthy individuals without oral lesions and 20 patients with oral cancer. Results: The mean values of salivary nitric oxide levels were significantly greater in oral cancer patients (126.2155+/- 2.7587) when compared to that of controls (76.111+/-μM/L). Similarly the extent of DNA damage was higher in subjects with oral cancer (28.099+/- 1.2696) than in controls (9.15+/- 0.9131). Pearson's correlation between nitric oxide levels in saliva and extent of DNA damage were found to be moderately correlated in controlsr=0.491 (p<0.01) and in oral cancer patientsr=0.428 (p<0.01). Conclusion: The results of present study illustrate an active involvement of nitric oxide which is derived from tobacco and its related products in the initiation of DNA damage and subsequent formation of oral cancer.

Dietary Pattern and Risk of Monoclonal Gammopathy of Undetermined Significance: A Population-Based Study

Background: All multiple myeloma (MM) cases are preceded by the premalignant state, monoclonal gammopathy of undetermined significance (MGUS). The etiology of MM and MGUS is to a large extent unknown. Few studies on the effect of diet on MM have been conducted and the results have been inconclusive. No studies have been conducted on the effect of diet on MGUS. Studying dietary patterns offers broader view of food consumption and possible effects of diet on diseases since many nutrients and other substances in foods act together. The aim of this study was to identify different dietary patterns at three time points throughout the lifespan and examine whether adherence to these patterns was associated with risk of MGUS and light chain MGUS (LC-MGUS) and progression to MM and other lymphoproliferative diseases.Methods: This study was based on participants from the AGES-Reykjavik Study (N=5,764; mean age 77 years). Participants gave information on frequency of intake of common foods from early life (14-19 years old), midlife (45-55 years old), and currently at study baseline (67 years and older). All participants were screened for MGUS and LC-MGUS by serum protein electrophoresis and serum free light-chain assay. We identified MM and other lymphoproliferative diseases by cross linking with the Icelandic Cancer Registry. Principal component analysis was used to extract dietary patterns. This method is data driven and forms new linear factors, (dietary patterns) by reducing data dimension and grouping correlated variables (food intake). For each pattern extracted a new variable is created, ranking participants on their adherence to that particular pattern. We used logistic regression to test association between adherence to the early life and midlife dietary patterns and MGUS and LC-MGUS, and Cox proportional hazard regression to test association between adherence to the late life patterns and progression to MM and other lymphoproliferative diseases.Results: A total of 300 (5.2%) MGUS cases and 52 (0.9%) LC-MGUS cases were identified. During 11 years of follow-up 18 cases had progressed to MM and 10 to other lymphoproliferative diseases. We extracted four dietary patterns from early life, four from midlife, and six from baseline. When analyzing MGUS and LC-MGUS cases combined we found that high adherence to pattern I from early life, the old traditional Icelandic diet (high intake of salted/smoked meat and fish, blood and liver sausage, rye bread, milk, oatmeal, and potatoes), decreased the risk (odds ratio (OR) = 0.89, 95% confidence interval (CI) 0.79-1.00), however no association was found when analyzing MGUS and LC-MGUS separately (Table 1). When analyzing midlife patterns we found that the estimate for pattern I, the old traditional Icelandic diet (high intake of salted/smoked meat and fish, blood and liver sausage, fish in salad or on bread, and meat meals) was similar to the findings from early life, although it did not reach a statistical significance (OR = 0.90, 95% CI 0.80 - 1.02). High adherence to pattern III (high intake of potatoes, whole wheat bread, milk, rye bread, and fish) from midlife decreased the risk of combined MGUS (OR = 0.88, 95% CI 0.79-0.98). When analyzing MGUS and LC-MGUS separately we found that high adherence to pattern III decreased the risk of LC-MGUS (OR = 0.69, 95% CI 0.53-0.90) but not MGUS. We did not find an association between the six patterns from late life and progression to MM. However when analyzing progression to MM and other lymphoproliferative diseases combined we found that high adherence to pattern VI (high intake of meat and milk, low intake of fish) increased the risk of progression (HR = 1.82, 95% CI 1.24-2.67). Further results can be seen in Table 1.Conclusion: Our findings suggest that high adherence to the old traditional Icelandic diet consumed during early and mid 19th century, including salted or smoked meat and fish, blood or liver sausage, rye bread, and potatoes decreases the risk of MGUS/LC-MGUS later in life. They additionally suggest an increased risk of progression to MM and other lymphoproliferative diseases, with high adherence to a pattern with high meat and low fish intake. The mechanisms for these findings are unknown but our study suggests that food intake can alter the risk of developing MGUS/LC-MGUS as well as the risk of progression to MM. [Display omitted] DisclosuresKorde:Medscape: Honoraria. Landgren:Medscape Myeloma Program: Honoraria; BMS: Honoraria; Takeda: Honoraria; Merck: Honoraria; Amgen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding.

Spectrum of Concomitant and Subsequently Diagnosed Second Malignancies in Patients with Chronic Myelomonocytic Leukemia

▪Background: An increased incidence of second skin and visceral malignancies in comparison to the general population has been reported in patients with hematologic neoplasms such as, chronic lymhocytic leukemia (CLL) (~11-36%) (Tsimberidou, JCO, 2009),chronic myeloid leukemia (CML) (4-6%) (Miranda, Leukemia 2016)and multiple myeloma (MM) (3-4.3%) (Palumbo, Lancet Oncol 2014).Diverse etiologies exist for this association. We carried out this study to describe the spectrum of second malignancies in patients with chronic myelomonocytic leukemia (CMML).Methods: Patients with World Health Organization defined CMML were included in the study. All patients had bone marrow (BM) biopsies performed at diagnosis. We only included malignancies that were diagnosed at the time of CMML diagnosis or subsequent to it. Patients that had concomitant systemic mastocytosis (n=18), therapy related CMML (n=19) and those that underwent allogeneic stem cell transplantation (n=23) were excluded. Standard cancer specific diagnostic and staging methods were utilized.Results: The study included 378 patients (median age 71 years; 66% males). Seventy-one concomitant and/or subsequent second malignancies were identified in thirty-two (8%) patients. Age group distribution was; 50-59 years 1 (1%), 60-69 years 21 (30%), 70-79 years 30 (42%) and ≥ 80 years 19 (27%) second malignancies. 22 (69%) patients had 1 second malignancy, 4 (13%) had 2, 2 (6%) had 4 (skin neoplasms), while 4 (13%) patients had ≥ 5 second malignancies (Table one). At a median follow-up of 18 months, 284 (75%) deaths and 54 (14%) leukemic transformations were documented.i) Second hematological malignancies:Thirteen (18%) concomitant (n=7, 54%) and subsequent hematological malignancies (n=6, 46%) were observed in 13 (3.5%) patients. In addition, 10 (3%) pre malignant states including, 7 patients with MGUS and 3 with monoclonal B-cell lymphocytosis (MBL) were seen. In one case each, the MGUS and MBL evolved into multiple myeloma (after 16 months) and CLL (after 30 months), respectively. Concomitant malignancies included: polycythemia vera (n=2, 15%), MM (n=2, 15%), marginal zone B-cell lymphoma (n=1, 8%), splenic lymphoma (n=1, 8%), ALK-rearranged T-cell lymphoma (n=1, 8%), while subsequent malignancies included: MM (n=1, 8%), diffuse large B-cell lymphoma (n=1, 8%), Waldenström’s macroglobulinemia (n=1, 8%), CLL (n=2, 15%) and acute lymphoblastic leukemia (n=1, 8%). Four (31%) patients needed chemotherapy, with outcomes including: complete remission in one case (multiple myeloma), progression of disease in 2 (multiple myeloma and diffuse large B cell-lymphoma) and partial response in 1 case (ALK rearranged T cell lymphoma). CMML related cytopenias did not preclude patients from getting chemotherapy. Three patients died from causes related to their second malignancies.ii) Cutaneous malignancies:Fifty-one (71%) concomitant (n=12, 24%) and subsequent cutaneous malignancies (n=39, 76%) were seen in 13 (3%) patients. The concomitant malignancies included: 7 (14%) basal cell carcinoma (BCC), 5 (10%) squamous cell carcinoma (SCC), while subsequent cancers included: 3 (6%) malignant melanoma, 7 (14%) BCC and 29 (57%) SCC. Four cases (8%) were locally advanced and four patients (8%) had recurrent lesions. A concomitant diagnosis of BCC and SCC was made in 8 patients (16%). All patients were treated surgically or with electrodesiccation and curettage. No deaths or metastases were reported.iii) Visceral malignancies:Seven (10%) subsequent visceral malignancies were seen in 6 (1%) patients. These included; colonic adenocarcinoma (n=2, 29%), bladder adenocarcinoma (n=1, 14%), endometrial adenocarcinoma (n=1, 14%), prostate adenocarcinoma (n=1, 14%), clear cell renal carcinoma (n=1, 14%) and papillary thyroid carcinoma (n=1, 14%). All the cases were localized and surgically resected, with two patients (colonic and endometrial adenocarcinoma) needing adjuvant chemo-radiotherapy. All patients achieved complete remission with no mortality related to second malignancies.Conclusions: Approximately 8% of CMML patients have second cutaneous (3.5%), hematological (3.5%) and visceral (1%) malignancies, with most of these occurring in and beyond the seventh decade (~70%) of life. Mortality related to second cancers was low (2%), with most patients receiving appropriate surgical and adjuvant chemo-radiation therapy. [Display omitted] DisclosuresAl-Kali:Celgene: Research Funding; Onconova Therapeutics, Inc.: Research Funding.

Epigenetic Activation of WNT5A Drives Glioblastoma Stem Cell Differentiation and Invasive Growth

Glioblastoma stem cells (GSCs) are implicated in tumor neovascularization, invasiveness, and therapeutic resistance. To illuminate mechanisms governing these hallmark features, we developed a de novo glioblastoma multiforme (GBM) model derived from immortalized human neural stem/progenitor cells (hNSCs) to enable precise system-level comparisons of pre-malignant and oncogene-induced malignant states of NSCs. Integrated transcriptomic and epigenomic analyses uncovered a PAX6/DLX5 transcriptional program driving WNT5A-mediated GSC differentiation into endothelial-like cells (GdECs). GdECs recruit existing endothelial cells to promote peritumoral satellite lesions, which serve as a niche supporting the growth of invasive glioma cells away from the primary tumor. Clinical data reveal higher WNT5A and GdECs expression in peritumoral and recurrent GBMs relative to matched intratumoral and primary GBMs, respectively, supporting WNT5A-mediated GSC differentiation and invasive growth in disease recurrence. Thus, the PAX6/DLX5-WNT5A axis governs the diffuse spread of glioma cells throughout the brain parenchyma, contributing to the lethality ofGBM.

ATM/CHK/p53 Pathway Dependent Chemopreventive and Therapeutic Activity on Lung Cancer by Pterostilbene.

Among the many stilbenoids found in a variety of berries, resveratrol and pterostilbene are of particular interest given their potential for use in cancer therapeutics and prevention. We purified four stilbenoids from R. undulatum and found that pterostilbene inhibits cancer cell proliferation more efficiently than rhapontigenin, piceatannol and resveratrol. To investigate the underlying mechanism of this superior action of pterostilbene on cancer cells, we utilized a reverse-phase protein array followed by bioinformatic analysis and found that the ATM/CHK pathway is modified by pterostilbene in a lung cancer cell line. Given that ATM/CHK signaling requires p53 for its biological effects, we hypothesized that p53 is required for the anticancer effect of pterostilbene. To test this hypothesis, we used two molecularly defined precancerous human bronchial epithelial cell lines, HBECR and HBECR/p53i, with normal p53 and suppressed p53 expression, respectively, to represent premalignant states of squamous lung carcinogenesis. Pterostilbene inhibited the cell cycle more efficiently in HBECR cells compared to HBECR/p53i cells, suggesting that the presence of p53 is required for the action of pterostilbene. Pterostilbene also activated ATM and CHK1/2, which are upstream of p53, in both cell lines, though pterostilbene-induced senescence was dependent on the presence of p53. Finally, pterostilbene more effectively inhibited p53-dependent cell proliferation compared to the other three stilbenoids. These results strongly support the potential chemopreventive effect of pterostilbene on p53-positive cells during early carcinogenesis.

DNMT3A and TET2 in the Pre-Leukemic Phase of Hematopoietic Disorders.

In recent years, advances in next-generation sequencing (NGS) technology have provided the opportunity to detect putative genetic drivers of disease, particularly cancers, with very high sensitivity. This knowledge has substantially improved our understanding of tumor pathogenesis. In hematological malignancies such as acute myeloid leukemia and myelodysplastic syndromes, pioneering work combining multi-parameter flow cytometry and targeted resequencing in leukemia have clearly shown that different classes of mutations appear to be acquired in particular sequences along the hematopoietic differentiation hierarchy. Moreover, as these mutations can be found in “normal” cells recovered during remission and can be detected at relapse, there is strong evidence for the existence of “pre-leukemic” stem cells (pre-LSC). These cells, while phenotypically normal by flow cytometry, morphology, and functional studies, are speculated to be molecularly poised to transform owing to a limited number of predisposing mutations. Identifying these “pre-leukemic” mutations and how they propagate a pre-malignant state has important implications for understanding the etiology of these disorders and for the development of novel therapeutics. NGS studies have found a substantial enrichment for mutations in epigenetic/chromatin remodeling regulators in pre-LSC, and elegant genetic models have confirmed that these mutations can predispose to a variety of hematological malignancies. In this review, we will discuss the current understanding of pre-leukemic biology in myeloid malignancies, and how mutations in two key epigenetic regulators, DNMT3A and TET2, may contribute to disease pathogenesis.

A Physical Mechanism and Global Quantification of Breast Cancer.

Initiation and progression of cancer depend on many factors. Those on the genetic level are often considered crucial. To gain insight into the physical mechanisms of breast cancer, we construct a gene regulatory network (GRN) which reflects both genetic and environmental aspects of breast cancer. The construction of the GRN is based on available experimental data. Three basins of attraction, representing the normal, premalignant and cancer states respectively, were found on the phenotypic landscape. The progression of breast cancer can be seen as switching transitions between different state basins. We quantified the stabilities and kinetic paths of the three state basins to uncover the biological process of breast cancer formation. The gene expression levels at each state were obtained, which can be tested directly in experiments. Furthermore, by performing global sensitivity analysis on the landscape topography, six key genes (HER2, MDM2, TP53, BRCA1, ATM, CDK2) and four regulations (HER2⊣TP53, CDK2⊣BRCA1, ATM→MDM2, TP53→ATM) were identified as being critical for breast cancer. Interestingly, HER2 and MDM2 are the most popular targets for treating breast cancer. BRCA1 and TP53 are the most important oncogene of breast cancer and tumor suppressor gene, respectively. This further validates the feasibility of our model and the reliability of our prediction results. The regulation ATM→MDM2 has been extensive studied on DNA damage but not on breast cancer. We notice the importance of ATM→MDM2 on breast cancer. Previous studies of breast cancer have often focused on individual genes and the anti-cancer drugs are mainly used to target the individual genes. Our results show that the network-based strategy is more effective on treating breast cancer. The landscape approach serves as a new strategy for analyzing breast cancer on both the genetic and epigenetic levels and can help on designing network based medicine for breast cancer.

Loss of TRAF3 Promotes a Premalignant Metabolic State in B cells.

Abstract TRAF3 is a signaling protein that acts as a tumor suppressor in B cells. B cell conditional TRAF3−/− mice display a remarkable expansion of B cell compartments and parenchymal B cell infiltration, attributed to enhanced B cell survival without increased proliferation. When aged, these mice develop lymphomas, and TRAF3 mutations are common in human B cell lymphoma and multiple myeloma. The mechanism of how loss of TRAF3 promotes B cell survival phenotype is not well understood; this particular role for TRAF3 is not seen in other immune cell types. We find that loss of TRAF3 leads to increased uptake of glucose in B cells in vitro and in vivo. This is accompanied by increased oxidative phosphorylation and glycolysis. In the absence of TRAF3, expression of Glut1 and Hexokinase II, two molecules important for glucose metabolism, is increased. Treatment of B cells with Glut1 inhibitor or the competitive glycolysis inhibitor 2-DG attenuates cell survival, and B cell viability is also substantially reduced in a glucose-free environment. Mechanistically, loss of TRAF3 leads to the induction of Pim2 kinase. Pim2 in turn promotes the protein stability of the oncogenic transcription factor c-Myc, known to drive expression of glycolytic genes. Our study shows that B cell deficiency of TRAF3 is sufficient for altered metabolic programming, consistent with a premalignant abnormal survival phenotype.

Examining the Relationship between Pre-Malignant Breast Lesions, Carcinogenesis and Tumor Evolution in the Mammary Epithelium Using an Agent-Based Model.

IntroductionBreast cancer, the product of numerous rare mutational events that occur over an extended time period, presents numerous challenges to investigators interested in studying the transformation from normal breast epithelium to malignancy using traditional laboratory methods, particularly with respect to characterizing transitional and pre-malignant states. Dynamic computational modeling can provide insight into these pathophysiological dynamics, and as such we use a previously validated agent-based computational model of the mammary epithelium (the DEABM) to investigate the probabilistic mechanisms by which normal populations of ductal cells could transform into states replicating features of both pre-malignant breast lesions and a diverse set of breast cancer subtypes.MethodsThe DEABM consists of simulated cellular populations governed by algorithms based on accepted and previously published cellular mechanisms. Cells respond to hormones, undergo mitosis, apoptosis and cellular differentiation. Heritable mutations to 12 genes prominently implicated in breast cancer are acquired via a probabilistic mechanism. 3000 simulations of the 40-year period of menstrual cycling were run in wild-type (WT) and BRCA1-mutated groups. Simulations were analyzed by development of hyperplastic states, incidence of malignancy, hormone receptor and HER-2 status, frequency of mutation to particular genes, and whether mutations were early events in carcinogenesis.ResultsCancer incidence in WT (2.6%) and BRCA1-mutated (45.9%) populations closely matched published epidemiologic rates. Hormone receptor expression profiles in both WT and BRCA groups also closely matched epidemiologic data. Hyperplastic populations carried more mutations than normal populations and mutations were similar to early mutations found in ER+ tumors (telomerase, E-cadherin, TGFB, RUNX3, p < .01). ER- tumors carried significantly more mutations and carried more early mutations in BRCA1, c-MYC and genes associated with epithelial-mesenchymal transition.ConclusionsThe DEABM generates diverse tumors that express tumor markers consistent with epidemiologic data. The DEABM also generates non-invasive, hyperplastic populations, analogous to atypia or ductal carcinoma in situ (DCIS), via mutations to genes known to be present in hyperplastic lesions and as early mutations in breast cancers. The results demonstrate that agent-based models are well-suited to studying tumor evolution through stages of carcinogenesis and have the potential to be used to develop prevention and treatment strategies.

A physical mechanism of cancer heterogeneity.

We studied a core cancer gene regulatory network motif to uncover possible source of cancer heterogeneity from epigenetic sources. When the time scale of the protein regulation to the gene is faster compared to the protein synthesis and degradation (adiabatic regime), normal state, cancer state and an intermediate premalignant state emerge. Due to the epigenetics such as DNA methylation and histone remodification, the time scale of the protein regulation to the gene can be slower or comparable to the protein synthesis and degradation (non-adiabatic regime). In this case, many more states emerge as possible phenotype alternations. This gives the origin of the heterogeneity. The cancer heterogeneity is reflected from the emergence of more phenotypic states, larger protein concentration fluctuations, wider kinetic distributions and multiplicity of kinetic paths from normal to cancer state, higher energy cost per gene switching, and weaker stability.

Transforming Cancer Prevention through Precision Medicine and Immune-oncology.

We have entered a transformative period in cancer prevention (including early detection). Remarkable progress in precision medicine and immune-oncology, driven by extraordinary recent advances in genome-wide sequencing, big-data analytics, blood-based technologies, and deep understanding of the tumor immune microenvironment (TME), has provided unprecedented possibilities to study the biology of premalignancy. The pace of research and discovery in precision medicine and immunoprevention has been astonishing and includes the following clinical firsts reported in 2015: driver mutations detected in circulating cell-free DNA in patients with premalignant lesions (lung); clonal hematopoiesis shown to be a premalignant state; molecular selection in chemoprevention randomized controlled trial (RCT; oral); striking efficacy in RCT of combination chemoprevention targeting signaling pathway alterations mechanistically linked to germline mutation (duodenum); molecular markers for early detection validated for lung cancer and showing promise for pancreatic, liver, and ovarian cancer. Identification of HPV as the essential cause of a major global cancer burden, including HPV16 as the single driver of an epidemic of oropharyngeal cancer in men, provides unique opportunities for the dissemination and implementation of public health interventions. Important to immunoprevention beyond viral vaccines, genetic drivers of premalignant progression were associated with increasing immunosuppressive TME; and Kras vaccine efficacy in pancreas genetically engineered mouse (GEM) model required an inhibitory adjuvant (Treg depletion). In addition to developing new (e.g., epigenetic) TME regulators, recent mechanistic studies of repurposed drugs (aspirin, metformin, and tamoxifen) have identified potent immune activity. Just as precision medicine and immune-oncology are revolutionizing cancer therapy, these approaches are transforming cancer prevention. Here, we set out a brief agenda for the immediate future of cancer prevention research (including a "Pre-Cancer Genome Atlas" or "PCGA"), which will involve the inter-related fields of precision medicine and immunoprevention - pivotal elements of a broader domain of personalized public health.

Abstract A2-63: Airway gene-coexpression network rewiring in the presence of bronchial dysplasia and lung cancer

Abstract Lung cancer is a deadly disease, killing 160,000 a year in the US. The 5-year survival rate of lung cancer patients is invariably low, partially due to a lack of early diagnoses and limited access to CT screening programs during the early, most-curable stages of the disease. The urgent need for alternative early-stage diagnostics has been addressed in previous work, which focused on smoking- and lung cancer-specific gene expression alterations in cytologically normal airway epithelial cells. These lung cancer associated alterations have been shown to serve as a clinically relevant biomarker for the early detection of lung cancer. In this study, we have expanded upon this work by leveraging gene expression from airway epithelial cells collected in the presence of bronchial premalignant lesions. Specifically, we conducted network-based analyses to further explore alterations in bronchial gene coexpression (GCE) patterns in the uninvolved large airway of patients with tobacco-induced premalignancy and those with lung cancer. By studying airway GCE patterns present in patients with lung cancer and premalignancy, but absent in disease-free smokers, we hope to discover the earliest changes in process of lung carcinogenesis that may serve as novel targets for lung cancer treatment and prevention. Coexpression networks use expression-profile correlations to cluster genes to provide system-wide context for single genes implicated in a disease and elucidate the influence of interconnectedness of cellular components on phenotype. Here, we employed Weighted Gene Coexpression Network Analysis (WGCNA) to build GCE networks derived from cytologically normal airway epithelial cells obtained from current and former smokers with lung cancer (n=409), dysplastic airway lesions (n=121), and neither condition (n=412). Samples were collected from subjects undergoing white-light bronchoscopy as part of the AEGIS trial by Allegro Dx, or from subjects undergoing autofluorescence bronchoscopy in the British Columbia Lung Health Study. RNA was extracted from cells and profiled on microarrays or by mRNA-Seq. In order to detect and quantify reconfiguration of networks under different disease states, the Modular Differential Connectivity (MDC) measure was calculated to determine the degree of topological similarity between any pair of GCE modules. In addition, Fisher's Exact Test (FET) was used to calculate significance of gene-member overlap between pairs of GCE modules originating from disease networks to distinguish modules conserved in premalignancy and cancer. To identify modules conserved between disease states, but dissimilar from the healthy smoker modules, we focused on those with (a) significant overlap by FET, (b) non-differentiating premalignancy vs. cancer MDC and (c) differentiating normal vs. disease MDC. Hub genes within each network were identified based on intra-modular connectivity, a measure of module essentiality. We prioritized genes with increased connectivity upon entering the premalignant state that remained strong in the lung cancer network. We identified 16 module pairs conserved between disease states, i.e. cancer modules similarly connected (MDC FDR&amp;lt;0.05) and significantly overlapping (pFET&amp;lt;0.01) with premalignancy modules, one of which was weakly connected in the disease-free networks (MDC FDR&amp;lt;0.05). Functional annotation of these modules revealed associations with pathways and transcription factors implicated in carcinogenesis and cell proliferation. Furthermore, we identified two hub genes linked to pathways regulating cigarette smoke-induced signaling and inhibition of lung cancer cell growth. Integration of differential connectivity and GCE network analyses represents a novel approach to discovering pathways associated with early lung carcinogenesis. Our results suggest the occurrence of transcriptomic alterations that arise in patients with premalignancy and remain present in patients with lung cancer. Future work will include experimental validation of these findings. The computational approach outlined above may aid in the identification of candidate master regulators of early lung carcinogenesis that have potential utility both as indicators of increased lung cancer risk and as early-stage drug targets for chemoprevention or therapy. Citation Format: Anna Tassinari, Bin Zhang, Katrina Steiling, Duncan Whitney, Kate Porta, Stephen Lam, Marc Lenburg, Avrum Spira, Jennifer Beane. Airway gene-coexpression network rewiring in the presence of bronchial dysplasia and lung cancer. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A2-63.

Abstract B1-17: Airway gene-coexpression network rewiring in the presence of bronchial dysplasia and lung cancer

Abstract Lung cancer is a deadly disease, killing 160,000 a year in the US. The 5-year survival rate of lung cancer patients is invariably low, partially due to a lack of early diagnoses and limited access to CT screening programs during the early, most-curable stages of the disease. The urgent need for alternative early-stage diagnostics has been addressed in previous work, which focused on smoking- and lung cancer-specific gene expression alterations in cytologically normal airway epithelial cells. These lung cancer associated alterations have been shown to serve as a clinically relevant biomarker for the early detection of lung cancer. In this study, we have expanded upon this work by leveraging gene expression from airway epithelial cells collected in the presence of bronchial premalignant lesions. Specifically, we conducted network-based analyses to further explore alterations in bronchial gene coexpression (GCE) patterns in the uninvolved large airway of patients with tobacco-induced premalignancy and those with lung cancer. By studying airway GCE patterns present in patients with lung cancer and premalignancy, but absent in disease-free smokers, we hope to discover the earliest changes in process of lung carcinogenesis that may serve as novel targets for lung cancer treatment and prevention. Coexpression networks use expression-profile correlations to cluster genes to provide system-wide context for single genes implicated in a disease and elucidate the influence of interconnectedness of cellular components on phenotype. Here, we employed Weighted Gene Coexpression Network Analysis (WGCNA) to build GCE networks derived from cytologically normal airway epithelial cells obtained from current and former smokers with lung cancer (n=409), dysplastic airway lesions (n=121), and neither condition (n=412). Samples were collected from subjects undergoing white-light bronchoscopy as part of the AEGIS trial by Allegro Dx, or from subjects undergoing autofluorescence bronchoscopy in the British Columbia Lung Health Study. RNA was extracted from cells and profiled on microarrays or by mRNA-Seq. In order to detect and quantify reconfiguration of networks under different disease states, the Modular Differential Connectivity (MDC) measure was calculated to determine the degree of topological similarity between pairs of GCE modules. In addition, Fisher's Exact Test (FET) was used to calculate significance of gene-member overlap between pairs of GCE modules originating from disease networks to distinguish modules conserved in premalignancy and cancer. To identify modules conserved between disease states, but dissimilar from the healthy smoker modules, we focused on those with (a) significant overlap by FET, (b) non-differentiating premalignancy vs. cancer MDC and (c) differentiating normal vs. disease MDC. Hub genes within each network were identified based on intra-modular connectivity, a measure of module essentiality. We prioritized genes with increased connectivity upon entering the premalignant state that remained strong in the lung cancer network. We identified 16 module pairs conserved between disease states, i.e. cancer modules similarly connected (MDC FDR&amp;lt;0.05) and significantly overlapping (pFET&amp;lt;0.01) with premalignancy modules, one of which was weakly connected in the disease-free networks (MDC FDR&amp;lt;0.05). Functional annotation of these modules revealed associations with pathways and transcription factors implicated in carcinogenesis and cell proliferation. Furthermore, we identified two hub genes linked to pathways regulating cigarette smoke-induced signaling and inhibition of lung cancer cell growth. Integration of differential connectivity and GCE network analyses represents a novel approach to discovering pathways associated with early lung carcinogenesis. Our results suggest the occurrence of transcriptomic alterations that arise in patients with premalignancy and remain present in patients with lung cancer. Future work will include experimental validation of these findings. The computational approach outlined above may aid in the identification of candidate master regulators of early lung carcinogenesis that have potential utility both as indicators of increased lung cancer risk and as early-stage drug targets for chemoprevention or therapy. Citation Format: Anna Tassinari, Bin Zhang, Katrina Steiling, Duncan Whitney, Kate Porta, Stephen Lam, Marc Lenburg, Avrum Spira, Jennifer Beane. Airway gene-coexpression network rewiring in the presence of bronchial dysplasia and lung cancer. [abstract]. In: Proceedings of the AACR Special Conference on Computational and Systems Biology of Cancer; Feb 8-11 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 2):Abstract nr B1-17.

CDKN2B Loss Promotes Progression from Benign Melanocytic Nevus to Melanoma.

Deletion of the entire CDKN2B-CDKN2A gene cluster is among the most common genetic events in cancer. The tumor-promoting effects are generally attributed to loss of CDKN2A-encoded p16 and p14ARF tumor suppressors. The degree to which the associated CDKN2B-encoded p15 loss contributes to human tumorigenesis is unclear. Here, we show that CDKN2B is highly upregulated in benign melanocytic nevi, contributes to maintaining nevus melanocytes in a growth-arrested premalignant state, and is commonly lost in melanoma. Using primary melanocytes isolated directly from freshly excised human nevi naturally expressing the common BRAF(V600E)-activating mutation, nevi progressing to melanoma, and normal melanocytes engineered to inducibly express BRAF(V600E), we show that BRAF activation results in reversible, TGFβ-dependent, p15 induction that halts proliferation. Furthermore, we engineer human skin grafts containing nevus-derived melanocytes to establish a new, architecturally faithful, in vivo melanoma model, and demonstrate that p15 loss promotes the transition from benign nevus to melanoma. Although BRAF(V600E) mutations cause melanocytes to initially proliferate into benign moles, mechanisms responsible for their eventual growth arrest are unknown. Using melanocytes from human moles, we show that BRAF activation leads to a CDKN2B induction that is critical for restraining BRAF oncogenic effects, and when lost, contributes to melanoma.