Multiple Genetic Alterations Research Articles

IL-6 Overexpression in ERG-Positive Prostate Cancer Is Mediated by Prostaglandin Receptor EP2

Prostate cancer is the most diagnosed cancer in men and multiple risk factors and genetic alterations have been described. The TMPRSS2-ERG fusion event and the overexpression of the transcription factor ERG are present in approximately 50% of all prostate cancer patients, however, the clinical outcome is still controversial. Prostate tumors produce various soluble factors, including the pleiotropic cytokine IL-6, regulating cellular processes such as proliferation and metastatic segregation. Here, we used prostatectomy samples in a tissue microarray format and analyzed the co-expression and the clinicopathologic data of ERG and IL-6 using immunohistochemical double staining and correlated the read-out with clinicopathologic data. Expression of ERG and IL-6 correlated strongly in prostate tissue samples. Forced expression of ERG in prostate tumor cell lines resulted in significantly increased secretion of IL-6, whereas the down-regulation of ERG decreased IL-6 secretion. By dissecting the underlying mechanism in prostate tumor cell lines we show the ERG-mediated up-regulation of the prostanoid receptors EP2 and EP3. The prostanoid receptor EP2 was overexpressed in human prostate cancer tissue. Furthermore, the proliferation rate and IL-6 secretion in DU145 cells was reduced after treatment with EP2-receptor antagonist. Collectively, our study shows that the expression of ERG in prostate cancer is linked to the expression of IL-6 mediated by the prostanoid receptor EP2.

Long Noncoding RNA RGMB-AS1 Indicates a Poor Prognosis and Modulates Cell Proliferation, Migration and Invasion in Lung Adenocarcinoma.

Lung cancer is the most common cause of cancer-related mortality worldwide. It is a complex disease involving multiple genetic and epigenetic alterations. The development of transcriptomics revealed the important role of long non-coding RNAs (lncRNAs) in lung cancer occurrence and development. Here, microarray analysis of lung adenocarcinoma tissues showed the abnormal expression of lncRNA RGMB-AS1. However, the role of lncRNA RGMB-AS1 in lung adenocarcinoma remains largely unknown. We showed that upregulation of lncRNA RGMB-AS1 was significantly correlated with differentiation, TNM stage, and lymph node metastasis. In lung adenocarcinoma cells, downregulation of lncRNA RGMB-AS1 inhibited cell proliferation, migration, invasion, and caused cell cycle arrest at the G1/G0 phase. In vivo experiments showed that lncRNA RGMB-AS1 downregulation significantly suppressed the growth of lung adenocarcinoma. The expression of lncRNA RGMB-AS1 was inversely correlated with that of repulsive guidance molecule b (RGMB) in lung adenocarcinoma tissues, and UCSC analysis and fluorescence detection assay indicated that lncRNA RGMB-AS1 may be involved in the development of human lung adenocarcinoma by regulating RGMB expression though exon2 of RGMB. In summary, our findings indicate that lncRNA RGMB-AS1 may play an important role in lung adenocarcinoma and may serve as a potential therapeutic target.

Molecular alterations in hepatocellular carcinoma associated with hepatitis B and hepatitis C infections.

Chronic infections with hepatitis B (HBV) and hepatitis C viruses (HCV) are the leading cause of cirrhosis and hepatocellular carcinoma (HCC) worldwide. Both viruses encode multifunctional regulatory proteins activating several oncogenic pathways, which induce accumulation of multiple genetic alterations in the infected hepatocytes. Gene mutations in HBV- and HCV-induced HCCs frequently impair the TP53, Wnt/b-catenin, RAS/RAF/MAPK kinase and AKT/mTOR pathways, which represent important anti-cancer targets. In this review, we highlight the molecular mechanisms underlying the pathogenesis of primary liver cancer, with particular emphasis on the host genetic variations identified by high-throughput technologies. In addition, we discuss the importance of genetic alterations, such as mutations in the telomerase reverse transcriptase (TERT) promoter, for the diagnosis, prognosis, and tumor stratification for development of more effective treatment approaches.

Fine-tuning patient-derived xenograft models for precision medicine approaches in leukemia

Many leukemias are characterized by well-known mutations that drive oncogenesis. Mice engineered with these mutations provide a foundation for understanding leukemogenesis and identifying therapies. However, data from whole genome studies...

Abstract A10: Oncogenomic analysis of IGF-IR driven mammary tumors identifies a potential cell of origin and mechanisms of tumor recurrence

Abstract Genetically engineered mice are valuable tools for understanding the genetic events that contribute to breast cancer development and progression. We have previously generated a doxycycline (Dox) inducible model of breast cancer, MTB-IGFIR, in which overexpression of the human type-I IGF receptor (IGF-IR) leads to the rapid induction of ER-mammary tumors with mixed luminal and basal features. Following Dox withdrawal and subsequent transgene downregulation, a subset of tumors escape IGF-IR dependence and spontaneously recur with evidence of an epithelial-mesenchymal transition (EMT). To gain insight into the molecular pathways that drive primary and recurrent tumor growth in MTB-IGFIR mice, we carried out gene expression profiling and DNA copy number analysis. Gene-set enrichment analysis (GSEA) revealed expression of an Akt oncogenic signature in primary tumors, consistent with downstream signaling mediated by IGF-IR. Interestingly, primary tumors also expressed a luminal progenitor gene signature suggesting a potential cell of origin. Accordingly, flow cytometric analysis of Dox-pulsed mice showed that high expression of the IGF-IR transgene was confined to EpCAM+/high Sca-1− cells, a putative ER- alveolar progenitor population. Recurrent tumors were found to express a mammary stem cell (MaSC) gene signature, which is consistent with their more mesenchymal phenotype as well as increased cell cycle pathway activity. While aCGH analysis identified few genomic changes in primary tumors, recurrent tumors exhibited gains and losses in known oncogenes and tumor suppressors including MET receptor, YAP1 and p16Ink4a/p19ARF. Integration of mRNA and copy number data confirmed altered expression of these genes at the transcriptional level. Taken together, these results suggest IGF-IR drives tumor initiation in an ER- luminal progenitor cell population in part through activation of the Akt pathway and that multiple genetic alterations contribute to the acquisition of oncogene independence and tumor relapse. Citation Format: Robert A. Jones, Craig I. Campbell, Katrina L. Watson, Roger A. Moorehead. Oncogenomic analysis of IGF-IR driven mammary tumors identifies a potential cell of origin and mechanisms of tumor recurrence. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A10.

A proteomics based approach for the identification of gastric cancer related markers.

Gastric cancer (GC) is the amongst the most common cancer types causing second largest number of cancer related deaths globally. GC is characterized as an aggressive malignancy which is very tough to be detected at an early stage. GC has been defined as a complex, multistep process involving multiple genetic and epigenetic alterations leading to aberrant expression of key regulating factors. GC according to WHO has been defined as malignant epithelial tumors of the gastric mucosa with glandular differentiation. About one half of the GCs are located in the lower stomach, and remaining is located in the corpus and fundus of the stomach (20%), lesser curvature (20%), cardia (10%) and greater curvature (3%). GC has been classified into intestinal and diffuse types based on epidemiological and clinico- and histopathological features. The etiology of GC is multifactorial and includes dietary as well as non-dietary factors. Despite a lot of research efforts, GC remains to be the cancer without clear symptoms at onset, poor prognosis, with metastasis and recurrence. Thus, there is an urgent need for identifying novel and diagnostic GC biomarkers and techniques with high sensitivity and specificity. In the present review, we provide a synopsis of proteomics based GC biomarkers discovered from various cancerous specimens such as blood, gastric fluid, tissues, cells and H. pylori infected cancer cell lines. The advent of proteomics based GC biomarkers will be a great asset for the early detection and treatment of GC.

Anticancer Drug Combinations, Studies for All Possibilities

Most cancer therapies are seldom effective by using single anticancer drug therapeutics based on multiple tumor genetic alterations and molecular abnormalities. Drug combinations are commonly practiced in clinics. Yet, anticancer drug combination utilities need to transform from empirical to science-guided enterprises. This editorial offers the background knowledge of drug combination therapies by mathematical enquiry.

Association of The IDH1 C.395G>A (R132H) Mutation with Histological Type in Malay Brain Tumors

Background:Brain tumors, constituting one of the most deadly forms of cancer worldwide, result from the accumulation of multiple genetic and epigenetic alterations in genes and signaling pathways. Isocitrate dehydrogenase enzyme isoform 1 (IDH1) mutations are frequently identified in primary brain tumors and acute myeloid leukemia. Studies on IDH1 gene mutations have been extensively performed in various populations worldwide but not in Malaysia. This work was conducted to study the prevalence of IDH1 c.395G>A (R132H) hotspot mutations in a group of Malaysian patients with brain tumors in order to gain local data for the IDH1 mutation profile in our population.Methods:Mutation analysis of c.395G>A (R132H) of IDH1 was performed in 40 brain tumor specimens by the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) and then verified by direct sequencing. Associations between the IDH1 c.395G>A (R132H) mutation and clinicopathologic characteristics were also analyzed.Results:The IDH1 c.395G>A (R132H) mutation was detected in 14/40 patients (35%). A significant association was found with histological tumor types, but not with age, gender and race.Conclusions:IDH1 is frequently mutated and associated with histological subtypes in Malay brain tumors.

Molecular Biomarkers of Pancreatic Intraepithelial Neoplasia and Their Implications in Early Diagnosis and Therapeutic Intervention of Pancreatic Cancer.

Lack of early detection and effective interventions is a major reason for the poor prognosis and dismal survival rates for pancreatic cancer. Pancreatic intraepithelial neoplasia (PanIN) is the most common precursor of invasive pancreatic ductal adenocarcinoma (PDAC). Each stage in the progression from PanIN to PDAC is well characterized by multiple significant genetic alterations affecting signaling pathways. Understanding the biological behavior and molecular alterations in the progression from PanIN to PDAC is crucial to the identification of noninvasive biomarkers for early detection and diagnosis and the development of preventive and therapeutic strategies for control of pancreatic cancer progression. This review focuses on molecular biomarkers of PanIN and their important roles in early detection and treatment of pancreatic cancer.

Concomitant BCR-ABL1 positive chronic myelogenous leukemia emerging in a patient with MPL W515L associated primary myelofibrosis

Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell disorders characterized by proliferation of one or more cell lineages in the bone marrow. At present, the main criterion in the 2008 World Health Organization classification of MPNs is the presence of an underlying genetic abnormality. These mutations are generally mutually exclusive except for rare reports in the literature. We report for the first time a detailed analysis of the clinical, histologic and cytogenetic/molecular features of a patient who initially presented with MPL W515L positive primary myelofibrosis and over the course of five years developed an MPN associated with both BCR-ABL1 and MPL W515L mutation. We discuss the diagnostic challenges and therapeutic implications of concomitant BCR-ABL1 translocation with MPL W515L mutation. Multiple genetic alterations may simultaneously coexist in patients exhibiting features of myeloproliferative disorders.

Hepatocellular carcinoma and estrogen receptors: Polymorphisms and isoforms relations and implications

Hepatocellular carcinoma (HCC) is the most common primary tumor of liver and its incidence continues to increase worldwide. HCC is a disease with multifactorial causes and genetic variability has been discussed as a risk factor for its development. Liver is a hormone-sensitive organ and therefore is influenced by gonadal hormones, such as estrogen. Estrogen is known to participate in various biological functions, but its role in development of HCC, on the other hand, is controversial and presents evidence suggesting a role as both a carcinogen and protective effect in liver. Estrogen way of action is mediated by estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), that belong to a family of nuclear receptors that may regulate the expression of many genes. The ER subtypes exert a variety of roles in many stages of liver disease and may play a part in the process of signal transduction, according to some studies. However, the many functions of ER subtypes in hepatic diseases, in special of the ERβ, are yet to be clarified.The genetic modifications related to HCC are not yet fully clarified and accumulation of multiple genetic alterations appears to have an important role in carcinogenesis of HCC. The presence of some certain single nucleotide polymorphism (SNP) may have a functional repercussion related to final product of a gene, which can be measured and may participate in some alterations related to a pathological condition.Our hypothesis is based on the fact that liver tissue express ER and its different variants exert multiple functions in various stages of liver disease and participate in an extremely complicated signal transduction process, therefore we believe that the presence of one or more SNPs of ESR1 and ESR2 genes may be related with the increase of risk in developing and the severity of HCC, as well as in the response to different treatments. The confirmation of our hypothesis by scientific studies may provide knowledge of markers that act as prognostic factors of this disease, as well as enabling alternatives to development of anti tumoral therapies.

MicroRNA-16 mediates the regulation of a senescence–apoptosis switch in cutaneous T-cell and other non-Hodgkin lymphomas

Multiple sequential genetic and epigenetic alterations underlie cancer development and progression. Overcoming cellular senescence is an early step in cancer pathogenesis. Here, we demonstrate that a noncoding regulatory RNA, microRNA-16 (miR-16), has the potential to induce cellular senescence. First, we examined the expression of miR-16 in primary cutaneous T-cell lymphoma (CTCL) and other non-Hodgkin T/natural killer (NK)-cell lymphomas and found that miR-16 was downregulated than that in the corresponding normal cells. Notably, miR-16 expression was reduced as the primary CTCL progressed from the early stage to the advanced stage. Next, we transduced CTCL cells with miR-16 to examine whether this miRNA exhibited tumor-suppressive effects in CTCL cells. In CTCL cells expressing wild-type p53, forced expression of miR-16 enhanced p21 expression via downregulation of the polycomb group protein Bmi1, thereby inducing cellular senescence. Alternatively, in CTCL cells lacking functional p53, miR-16 induced compensatory apoptosis. The miR-16 transfection significantly decreased senescent cells and increased apoptotic cells in p21-knockdown CTCL cells expressing wild-type p53, suggesting that the presence or absence of p21 may be the most important condition in the senescence-apoptosis switch in CTCL lymphomagenesis. Furthermore, we found that the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) restored the expression of miR-16 and its essential targets, induced senescence in CTCL cells expressing wild-type p53 and promoted apoptosis in cells with nonfunctional p53. Moreover, we found that other T/NK-cell lymphoma cell lines showed similar tumor-suppressive effects in response to miR-16 and SAHA and that these effects were dependent on p53 status. These results suggested that epigenetic silencing of miR-16 may be a key step during lymphoma development. Elucidation of the essential targets of miR-16 and SAHA provides a basis for the clinical application of SAHA in the treatment of CTCL and other non-Hodgkin T/NK-cell lymphomas.

Microrna-16 Mediates the Regulation of a Senescence-Apoptosis Switch in Cutaneous T-Cell and Other Non-Hodgkin Lymphomas

Multiple sequential genetic and epigenetic alterations, including alterations in microRNAs (miRNAs), underlie the development and progression of cancers. For example, overcoming cellular senescence is an early step in cancer pathogenesis. We show here that a tumor-suppressive miRNA, microRNA-16/miR-16 has a potential to induce cellular senescence in cutaneous T-cell lymphoma (CTCL). Firstly, to examine the role of miR-16 in the progression of primary CTCL, we performed q-PCR analysis against early (n=26) and advanced (n=14) Mycosis Fungoides samples. As for control (CD4+ T-cells), we used samples from patients with atopic dermatitis (AD; n=18). We found that expression of miR-16 in both early and advanced stages were significantly lower than AD, with the expression of advanced showing significantly more reduced than early stage. These results suggest that miR-16 is associated with lymphomagenesis from early to advanced stages of CTCL. To examine in vivo tumor-suppressive effects of miR-16, we used NOD/Shi-scid IL2Rgnull (NOG) mouse xenograft model, which would die around day 30-40 after CTCL cells (My-La, MJ, HH or HUT78) injection by invasion and metastasis (Ito et al, Blood 2014). By use of the xenograft model, we found that miR-16 transduced CTCL cells transplanted NOG mice showed significant prolonged survivals than control xenograft mice. We previously demonstrated that miR-16 did not inhibit migration capability of CTCL cells. When we considered that miR-16 successfully contribute to extend survival of mice models despite of lacking migration-inhibition capability, the result suggested that other tumor suppressive mechanisms might exist. Therefore we conducted functional analysis of miR-16, and found that miR-16 could induce cellular senescence against CTCL cells. In CTCL cells that expressed wild-type p53 (My-La and MJ), forced expression of miR-16 enhanced p21, which is a key mediator of senescence, in a p53 dependent manner. Because miR-16 family members are also able to directly suppress the polycomb group protein Bmi1, which is known to negatively regulate p21, we assessed Bmi1 expression in miR-16-transduced CTCL cells and found it to be diminished in all four CTCL cell lines tested. When we knocked down BMI1, expression of p21 was elevated in cells expressing wild-type p53 and the incidence of senescence was increased. We further demonstrated that Bmi1 could directly interact with the promoter lesion of CDKN1A/p21 by cross-linking/chromatin immunoprecipitation assays. From these results, miR-16 has potential to induce cellular senescence via targeting Bmi1-p21 pathway in p53-wild type CTCL cells. Although miR-16 could not induce senescence in p53 non-functional CTCL cells (HH and HUT78), in that case, we found that miR-16 can compensatory induce apoptosis by negative regulation of Bmi1-Survivin pathway. To elucidate this senescence-apoptosis switch mechanism, we examined co-transfection of miR-16 and siCDKN1A/p21 against p53 wild-type CTCL cells. We found that co-transfection of miR-16 and siCDKN1A significantly decreased senescent cells and increased apoptotic cells, with downregulation of Bmi1 and Survivin. In addition, miR-16 negatively regulated cyclinD1-Rb pathway regardless of p53 status, leading to cell growth inhibition against CTCL cells. Together, these results strongly support our idea that presence or absence of functional p53-p21 is an essential factor in miR-16-mediated senescence-to-apoptosis switch in CTCL. Finally, because a histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA, vorinostat) has been recently applied and marks good responses in advanced CTCL, we tried to examine whether SAHA might share essential targets with miR-16 in CTCL lymphomagenesis. We found that SAHA restored miR-16 and its essential targets (p21, Bmi1, Survivin), and induced senescence in CTCL cells with wild-type p53 and apoptosis in cells with non-functional p53. Moreover, we found that T or NK/T-cell lymphoma cells (n=8) derived from various subtypes also showed similar tumor-suppressive effects by miR-16 transduction or SAHA treatment. In conclusion, through detailed study of miR-16 function, we have shed light on the mechanism by which lymphoma cells avoid senescence. Furthermore, identification of essential SAHA targets may provide supporting evidence of its clinical application for various non-Hodgkin T/NK-cell lymphomas. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

PI3K/MEK pathway-targeted therapy in non-small cell lung carcinoma

AbstractPulmonary carcinogenesis is a chronic process that involves multiple genetic, cellular and tissue alterations, resulting from changes in genes that regulate growth, differentiation and apoptosis, which eventually lead to the development of invasive or metastatic cancer. Lung cancer is divided into two groups: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC); the latter is more prevalent in the population since it represents approximately 75% of all lung tumours. During the development of NSCLC, different molecular events occur that include the loss of heterozygosity, epigenetic mutations in p53, KRAS and changes in receptor (EGFR), amplification of the cMET epidermal growth factor and microsatellite instability. It is important to note that mutations present in the EGFR are prevalent in adenocarcinomas of non-smoking, whereas in adenocarcinomas of the smokers are mutations in KRAS. Different molecular studies have reported changes in signalling pathways that contribute to lung ...

Overview of Transforming Growth Factor β Superfamily Involvement in Glioblastoma Initiation and Progression

Glioblastoma, also known as glioblastoma multiforme (GBM), is the most aggressive of human brain tumors and has a stunning progression with a mean survival of one year from the date of diagnosis. High cell proliferation, angiogenesis and/or necrosis are histopathological features of this cancer, which has no efficient curative therapy. This aggressiveness is associated with particular heterogeneity of the tumor featuring multiple genetic and epigenetic alterations, but also with implications of aberrant signaling driven by growth factors. The transforming growth factor β (TGFβ) superfamily is a large group of structurally related proteins including TGFβ subfamily members Nodal, Activin, Lefty, bone morphogenetic proteins (BMPs) and growth and differentiation factor (GDF). It is involved in important biological functions including morphogenesis, embryonic development, adult stem cell differentiation, immune regulation, wound healing and inflammation. This superfamily is also considered to impact on cancer biology including that of GBM, with various effects depending on the member. The TGFβ subfamily, in particular, is overexpressed in some GBM types which exhibit aggressive phenotypes. This subfamily impairs anti-cancer immune responses in several ways, including immune cells inhibition and major histocompatibility (MHC) class I and II abolishment. It promotes GBM angiogenesis by inducing angiogenic factors such as vascular endothelial growth factor (VEGF), plasminogen activator inhibitor (PAI-I) and insulin- like growth factor-binding protein 7 (IGFBP7), contributes to GBM progression by inducing metalloproteinases (MMPs), "pro-neoplastic" integrins (αvβ3, α5β1) and GBM initiating cells (GICs) as well as inducing a GBM mesenchymal phenotype. Equally, Nodal promotes GICs, induces cancer metabolic switch and supports GBM cell proliferation, but is negatively regulated by Lefty. Activin promotes GBM cell proliferation while GDF yields immune-escape function. On the other hand, BMPs target GICS and induce differentiation and sensitivity to chemotherapy. This multifaceted involvement of this superfamily in GBM necessitates different strategies in anti-cancer therapy. While suppressing the TGFβ subfamily yields advantageous results, enhancing BMPs production is also beneficial.

T134: Allelic imbalance and epigenetic changes as a marker of tumor spreading into the adjacent tissue

Non-small cell lung cancer (NSCLC) is characterized by multiple genetic alterations such as loss of heterozygosity (LOH), microsatellite instability (MSI), promoter hypermethylation and changes of miRNA expression. According to a field cancerization (FC) phenomenon the adjacent histologically normal tissue plays a role in tumor progression by triggering the transformation process. The aim of the study was the analysis of genetic alterations in tumor and adjacent tissue to determine the FC size and to reveal associations with clinico-morphological features of patients. The study group included 135 patients with NSCLC. From each patient 4 FFPE samples were analyzed: tumor, adjacent normal lung tissue at 2, 5, 10 cm. LOH/MSI analysis was evaluated by PCR using 7 microsatellite loci. Promoter hypermethylation in genes RASSF1A FHIT, DAPK1, CDH1, CD44, TIMP3, MGMT was investigated by methyl-sensitive PCR. The expression levels of miRNAs let-7a, miR-155, miR-205 were measured by real-time PCR. Our results demonstrated that LOH/MSI occurs only in tumor while promoter hypermethylation occurs also in adjacent tissue at 2, 5 cm, but not at 10 cm. The downregulation of let-7a, miR-155 in adjacent tissue is lower than in tumor. The levels of investigated miRNAs in adjacent tissue vary depending on tumor differentiation – in patients with differentiated tumors it is higher than in the group with poorly differentiated tumors. We postulate that FC size in NSCLC is at least 5 cm from tumor and includes only epigenetic but not structural (LOH/MSI) alterations. The evaluation of epigenetic changes in adjacent tissue (e.g., surgical margins) can potentially be used for postsurgical prognosis.

GENO-01MOLECULAR INTERROGATION OF GLIOBLASTOMA MULTIFORME TUMORS IDENTIFIES A COMPLEX NETWORK OF CELL SIGNALLING PATHWAYS WITH POSSIBLE THERAPEUTIC IMPLICATIONS

The precise molecular mechanism behind Glioblastoma Grade IV with extremely poor treatment outcome for patients with even intensive therapy regimen is yet to be completely understood. GBMs represent approximately 17% of all primary brain tumours diagnosed worldwide, and 60-75% of astrocytomas, increasing in frequency with age (WHO and IARC, 2008). Recent research has revealed four distinct subtypes based on multiple genetic alterations which have prognostic and therapeutic implications. Present study was performed to characterize global genomic analysis from ten GBM patients to study the molecular mechanisms and pathways associated with tumorigenesis and to understand the cause of therapy failure. Here we show that molecular interrogation clearly identifies GBM subtypes which seem to have distinct prognostic outcomes. Importantly, pathways known to play a role in the cancer stem cell (CSC) proliferation were found to be activated in several tumor specimens. Significantly, CSCs have been implicated in tumor maintenance and relapse after surgical resection. Most current anti-cancer drugs, small molecule inhibitors and monoclonal antibodies are designed to target rapidly proliferating cells which represent committed cancer cells but not CSCs and hence may partly explain cause of therapy failure. Further, multiple pathway activation in the GBM population calls for immediate attention to consider development of combination regimens / new target based drug development in GBMs. This could be an alternative to the template regimen which has now resulted in plateaued overall survival. We also observed a possible abetment by the metabolic engine in tumor progression and would need more study to consider its importance in GBM grading. Study further supports the urgent need for identifying global molecular signatures in GBM patients to align treatment for better outcomes and improved overall survivals.

Abstract IA38: Identification of targetable vulnerabilities in lymphoma.

Abstract Diffuse large B- cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma in adults and a clinically and genetically heterogeneous disorder. With current therapy, over 60% of patients with DLBCL can be cured; however, the remaining patients succumb to their disease. DLBCL largely originates in germinal center (GC) B cells, which have high growth rates and increased genomic instability. As a consequence, DLBCLs exhibit multiple low frequency genetic alterations including chromosomal translocations, somatic mutations and copy number alterations (CNAs). We have used several complementary comprehensive strategies to characterize the molecular heterogeneity of DLBCL and identify associated rational therapeutic targets. Using a combination of high-density – SNP arrays, whole exome sequencing, gene expression profiling and pathway analyses, we have comprehensively defined CNAs, candidate driver genes and perturbed signaling pathways in large series of newly diagnosed DLBCLs. The approach revealed a complementary set of CNAs and somatic mutations that decreased p53 activity and perturbed cell cycle regulation. The genetic signature of p53 deficiency and cell cycle deregulation was highly predictive for unfavorable outcome and potentially amenable to targeted therapy. We previously applied consensus clustering methods to the transcriptional profiles of primary DLBCLs and identified 3 highly reproducible tumor groups: BCR (B-cell receptor), OxPhos (oxidative phosphorylation) and HR (host response). “BCR” DLBCLs have increased expression of multiple components of the BCR signaling pathway and increased reliance on BCR-mediated survival signals. We recently characterized distinct BCR/SYK/PI3K-dependent survival pathways in DLBCLs with high or low baseline NF-κB activity and defined specific survival mechanisms in BCR-dependent NF-κB low DLBCLs. In these studies, SYK/PI3K/AKT-dependent cholesterol biosynthesis was found to be a feed-forward mechanism of preserving the integrity of BCRs in lipid rafts in DLBCLs with low- or high-baseline NF-κB. Consistent with the roles of SYK and PI3K/AKT as important mediators of BCR survival signals in primary DLBCLs, SYK amplification and PTEN deletion were identified as selective and largely mutually exclusive genetic alterations in “BCR”-type tumors. These studies suggest potential strategies for specifically targeting BCR-dependent survival signals in defined subtypes of DLBCL. In additional studies, we found that predominant fuel utilization pathways in BCR and OxPhos DLBCLs differ. Whereas BCR DLBCLs primarily utilize aerobic glycolysis, OxPhos DLBCLs largely depend upon fatty acid oxidation and exhibit selective sensitivity to targeted inhibition of this fuel utilization pathway. These findings further define molecular subsets of DLBCLs with distinct metabolic features that are linked to the functional state of upstream BCR signaling components. Citation Format: Margaret Shipp. Identification of targetable vulnerabilities in lymphoma. [abstract]. In: Proceedings of the AACR Special Conference on Hematologic Malignancies: Translating Discoveries to Novel Therapies; Sep 20-23, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(17 Suppl):Abstract nr IA38.

Genome-wide transcriptome analysis reveals inactivation of Wnt/β-catenin by 3,3'-diindolylmethane inhibiting proliferation of colon cancer cells.

Multiple genetic and signaling pathway alterations underlie the development of colon cancer. We utilized genome-wide transcriptome analysis to identify important gene expression patterns following treatment with 3,3'-diindolylmethane (DIM), a natural compound derived from cruciferous vegetables, on colon cancer cells. Statistical analyses of gene expression data from DIM treated cells revealed that 692genes were significantly upregulated, while 731genes were down-regulated. Putative gene networks showed that several oncogenes (β-catenin, Myc and FOS) were significantly suppressed by DIM treatment. Using clinical data from colon cancer patients, activation of β-catenin was found to be significantly associated with patient prognosis by Kaplan-Meir plot analysis. We validated the mRNA and protein expression levels of c-Myc, β-catenin, and cyclin D1, all of which were significantly suppressed after DIM treatment in DLD-1 and HCT116 cells. System level characterization of our findings suggests for the first time that β-catenin and c-Myc, which are major genes involved in colon carcinogenesis, were significantly downregulated by DIM treatment in colon cancer cells. Therefore, targeting Wnt/β-catenin signaling by DIM may be an attractive strategy for the prevention and treatment of colon cancer.

Cytotoxicity of 35 medicinal plants from Sudan towards sensitive and multidrug-resistant cancer cells

BackgroundCancer is a complex disease with multiple genetic and epigenetic alterations. Since decades, the hallmark of cancer therapy is chemotherapy. Cytotoxic drugs erase rapidly dividing cells without sufficient differentiation between normal and cancerous cells resulting in severe side effects in normal tissues. Recently, strategies for cancer treatment focused on targeting specific proteins involved in tumor growth and progression. The present study was designed to investigate the cytotoxicity of 65 crude extracts from 35 Sudanese medicinal plants towards various cancer cell lines expressing molecular mechanisms of resistance towards classical chemotherapeutics (two ATP-binding cassette transporters, ABCB1 (P-glycoprotein) and ABCB5, tumor suppressor p53, epidermal growth factors receptor (EGFR). And the aim was to identify plant extracts and isolated compounds thereof with activity towards otherwise drug-resistant tumor cells. MethodsCold maceration was performed to obtain crude extracts from the plants. The resazurin assay was used to determine cytotoxicity of the plant extracts. Microarray-based mRNA expression profiling, COMPARE, and hierarchical cluster analyses were applied to identify, which genes correlate with sensitivity or resistance to ambrosin, the main constituent of the most active extract Ambrosia maritima. ResultsThe results of the resazurin assay on different tumors showed that Lawsonia inermis, Trigonella foenum-graecum and Ambrosia maritma were the most active crude extracts. Ambrosin was selected as one active principle of A. maritima for microarray-based expression profiling. Genes from various functional groups (transcriptional regulators, signal transduction, membrane transporters, cytoskeleton organization, chaperones, immune system development and DNA repair) were significantly correlated with response of tumor cell lines to ambrosin. ConclusionThe results revealed cytotoxicity and pharmacogenomics studies of Sudanese medicinal plants provide an attractive strategy for the development of novel cancer therapeutics with activity towards cell lines that resistance to established anticancer agents.