Stages Of Cancer Development Research Articles

Abstract LB-231: Identifying cancer-related processes in normal tissues via RNA-seq

Abstract Cancer genome studies have significantly contributed to the discovery of somatic mutations and processes that drive cancer. However, how these mutations accumulate in normal cells and contribute to early cancer development remains poorly understood. Recent studies have addressed this question by studying normal blood and a small number of skin samples, discovering both driver mutations as well as mutational processes observed in cancer. Here we extend these studies by analyzing RNA from ~7,000 samples across 30 normal tissues from ~600 individuals compared to their germline DNA, collected as part of the GTEx project. To accomplish this goal we first developed a new pipeline termed RNA-MuTect for calling somatic mutations directly from RNA-seq samples and their matched-normal DNA. RNA-MuTect includes multiple filtering steps designed specifically for analyzing RNA-seq. We first validated RNA-MuTect by analyzing TCGA samples where both DNA and RNA data are available. Comparing the set of mutations detected by RNA-MuTect to those identified in the DNA, we show that whenever there is sufficient coverage to detect the mutations in RNA, we have a high sensitivity. Most importantly, RNA-MuTect has a very low false-positive rate with specificity >90%. We further demonstrate that we can discover most of the known driver genes in this cohort using the mutations detected based on the RNA data. Moreover, using the RNA data, we can detect the same mutational processes as identified in the DNA, including UV, aging, smoking and others. To study clonal expansion in normal tissues and investigate whether known cancer-related genes and processes can be identified, we applied RNA-MuTect to the GTEx dataset. As expected, multiple variants were detected across tissues, with skin, lung and esophagus having the highest number of somatic mutations. Overall, different cancer-related events were detected. Specifically: (1) we found 15 hotspot mutations in 6 different genes including TP53, KRAS and PIK3CA; (2) Mutated genes in 8 different tissues were found to be enriched with Cancer Gene Census genes; (3) Known cancer genes were found to be under positive selection in different tissues; (4) Known cancer-related mutational signatures were captured in normal tissues; (5) Cases of allelic imbalance were detected in various tissues. This study is the first to analyze a large number of samples across many tissues to explore the fundamental question of cancer initiation. Many cancer-related processes and events are discovered across different tissues, laying the foundation for studying the earliest stages of cancer development. Note: This abstract was not presented at the meeting. Citation Format: Keren Yizhak, Jaegil Kim, Francois Aguet, Julian Hess, Hailei Zhang, Eila Arich-Landkof, Noam Shoresh, Ayelet Segre, Chip Stewart, Dainel Rosebrock, Dimitri Livitz, Nicholas Haradhvala, Paz Polak, Tim Sullivan, Xiao Li, Kristin Ardlie, Gad Getz. Identifying cancer-related processes in normal tissues via RNA-seq [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 LB-231. doi:10.1158/1538-7445.AM2017-LB-231

Multifaceted Roles of Glutathione and Glutathione-Based Systems in Carcinogenesis and Anticancer Drug Resistance.

Glutathione is the most abundant antioxidant molecule in living organisms and has multiple functions. Intracellular glutathione homeostasis, through its synthesis, consumption, and degradation, is an intricately balanced process. Glutathione levels are often high in tumor cells before treatment, and there is a strong correlation between elevated levels of intracellular glutathione/sustained glutathione-mediated redox activity and resistance to pro-oxidant anticancer therapy. Recent Advances: Ample evidence demonstrates that glutathione and glutathione-based systems are particularly relevant in cancer initiation, progression, and the development of anticancer drug resistance. This review highlights the multifaceted roles of glutathione and glutathione-based systems in carcinogenesis, anticancer drug resistance, and clinical applications. The evidence summarized here underscores the important role played by glutathione and the glutathione-based systems in carcinogenesis and anticancer drug resistance. Future studies should address mechanistic questions regarding the distinct roles of glutathione in different stages of cancer development and cancer cell death. It will be important to study how metabolic alterations in cancer cells can influence glutathione homeostasis. Sensitive approaches to monitor glutathione dynamics in subcellular compartments will be an indispensible step. Therapeutic perspectives should focus on mechanism-based rational drug combinations that are directed against multiple redox targets using effective, specific, and clinically safe inhibitors. This new strategy is expected to produce a synergistic effect, prevent drug resistance, and diminish doses of single drugs. Antioxid. Redox Signal. 27, 1217-1234.

Dual function of MAZ mediated by FOXF2 in basal-like breast cancer: Promotion of proliferation and suppression of progression

Myc-associated zinc finger protein (MAZ) is a transcription factor with C2H2-type zinc-finger motifs that can bind GC-rich cis-elements. MAZ activates the transcription of some cancer-related genes and represses that of others, suggesting that changes in MAZ expression may play different roles in the development and progression of different types or subtypes of cancers depending on its target genes. However, the functions and mechanisms of MAZ in regulating the carcinogenesis and progression of breast cancer have remained unclear. In the current study, we show that MAZ performs dual function in basal-like breast cancer (BLBC): suppression of aggressiveness and promotion of proliferation. Forkhead box F2 (FOXF2) is a novel transcription target of MAZ and mediates the functions of MAZ. The MAZ mRNA level, particularly in combination with the FOXF2 mRNA level, may serve as a prognostic marker for BLBC patients. Our results indicate that the dual function of the MAZ-FOXF2 axis reflect the pleiotropic nature of multifunctional transcription factors in regulating the different stages of cancer development and progression, which could lead to the complexity of cancer diagnosis and treatment.

Label-Free Classification of a Nasopharyngeal Carcinoma Tissue Test at Different Stages Based on Raman Spectroscopy.

Raman spectroscopy (RS) of nasopharyngeal carcinoma (NPC) tissue provides substantial biomolecular information and various biomedicine features for tissue at different stages of cancer development. This study suggested an automatic and quick method for the classification of Raman spectra at different stages of NPC by multivariate statistical analysis. During RS measurement, Raman spectra were acquired from all NPC tissues in two groups of samples: 30 early-stage NPC patients (stages I and II) and 46 advanced-stage NPC patients (stages III and IV). In addition, a tentative diagnostic algorithm comprising principal components analysis and support vector machine was used to effectively classify multivariate data from the Raman spectra to yield sensitivities (70%; 21 of 30 samples) and specificities (91%; 42 of 46 samples) by the leave-one-out cross-validation method. Meaningful chemical compositions in the classification process were then deduced by analyzing the classified mathematical model. This beneficial work provides a great potential clinical method for the automatic classification of NPC stages and the speculation of the chemical compositions for NPC staging.

Highly Selective Capture Surfaces on Medical Wires for Fishing Tumor Cells in Whole Blood.

The detection of circulating tumor cells (CTCs) in the blood of cancer patients is a challenging task. CTCs are, especially at the early stages of cancer development, extremely rare cells hidden in a vast background of regular blood cells. We describe a new strategy for the isolation of CTCs from whole blood. The key component is a medical wire coated with a multilayer assembly that allows highly specific capture of EpCAM (epithelial cell adhesion molecule) positive CTCs from blood. The assembly is generated in a layer-by-layer fashion through photochemically induced C,H insertion reactions and consists of a protective layer, which shields the contacting solution from the metal, a protein resistant layer, which prevents nonspecific interactions with proteins and a layer containing the EpCAM antibodies. In vitro experiments show that these surfaces can capture tumor cells from whole blood with enrichment factors (specifically vs nonspecifically bound cells) of up to about 3000 compared to the number of leucocytes in the blood. The purity of the isolated cells is greater than 90%. After "fishing" them from the blood, the cells, still bound to the wire, can be genetically analyzed. This demonstrates that this strategy might prove useful for next generation sequencing.

Downregulation of transgelin blocks interleukin-8 utilization and suppresses vasculogenic mimicry in breast cancer cells.

Vasculogenic mimicry (VM) is a non-classical mechanism recently described in many tumors, whereby cancer cells, rather than endothelial cells, form blood vessels. Transgelin is an actin-binding protein that has been implicated in multiple stages of cancer development. In this study, we investigated the role of transgelin in VM and assessed its effect on the expression of endothelial and angiogenesis-related genes during VM in MDA-MB-231 breast cancer cells. We confirmed the ability of MDA-MB-231 cells to undergo VM through a tube formation assay. Flow cytometry analysis revealed an increase in the expression of the endothelial-related markers VE-cadherin and CD34 in cells that underwent VM, compared with those growing in a monolayer, which was confirmed by immunocytochemistry. We employed siRNA to silence transgelin, and knockdown efficiency was determined by western blot analyses. Downregulation of transgelin suppressed cell proliferation and tube formation, but increased IL-8 levels in Matrigel cultures. RT-PCR analyses revealed that the expression of IL-8, VE-cadherin, and CD34 was unaffected by transgelin knockdown, indicating that increased IL-8 expression was not due to enhanced transcriptional activity. More importantly, the inhibition of IL-8/CXCR2 signaling also resulted in suppression of VM with increased IL-8 levels, confirming that increased IL-8 levels after transgelin knockdown was due to inhibition of IL-8 uptake. Our findings indicate that transgelin regulates VM by enhancing IL uptake. These observations are relevant to the future development of efficient antivascular agents. Impact statement Vasculogenic mimicry (VM) is an angiogenic-independent mechanism of blood vessel formation whereby aggressive tumor cells undergo formation of capillary-like structures. Thus, interventions aimed at angiogenesis might not target the entire tumor vasculature. A more holistic approach is therefore needed in the development of improved antivascular agents. Transgelin, an actin-binding protein, has been associated with multiple stages of cancer development such as proliferation, migration and invasion, but little is known about its role in vasculogenic mimicry. We present here, an additional mechanism by which transgelin promotes malignancy by way of its association with the occurrence of VM. Although transgelin knockdown did not affect the transcript levels of most of the angiogenesis-related genes in this study, it was associated with the inhibition of the uptake of IL-8, accompanied by suppressed VM, indicating that transgelin is required for VM. These observations are relevant to the future development of efficient antivascular agents.

Preclinical PET, SPECT, CT, MRI and optical imaging in cancer research: An overview

Cancer research is primarily dependent on rodent models. There has been a huge advancement in anticancer drug discovery in the last two decades, which is mainly due to improved animal models and introduction of non-invasive imaging technologies. Non-invasive imaging technology plays an important role in cancer and other biomedical research areas including neurology, cardiology, nanotechnology and stem cell biology. The intricate pathways in cancer initiation, progression and metastasis can be visualized and the processes can be analyzed quantitatively using these techniques. Robust preclinical data is the backbone of anticancer drug discovery, which can be obtained precisely using imaging technology. This review is focused on the dedicated preclinical imaging modalities such as Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), X-ray Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Optical imaging and Cerenkov imaging. This paper discusses their present roles in basic and translational research towards evaluation of suitability of target molecules for further clinical trials.The unique features of the imaging modalities enable them to provide information necessary for understanding structural, functional and molecular processes involved in various stages of cancer development thus bridging the gap between bench and bedside.

Iodine Promotes Tumorigenesis of Thyroid Cancer by Suppressing Mir-422a and Up-Regulating MAPK1

Background/Aims: Iodine may trigger tumorigenesis and development of thyroid carcinoma, but the mechanisms involved remained elusive. MicroRNA (MiRNAs) are known to be involved in each stage of cancer development; however, the role of miRNAs in iodine-induced tumorigenesis of thyroid carcinoma remained unknown. In this study, we aimed at investigating miRNA related signaling pathway in thyroid cancer cells. Methods: Levels of miRNAs and mRNAs were determined using RT-qPCR and proteins were quantified by western blotting. Cell migration and proliferation were checked using Transwell assay and CCK8 assay respectively. Tumor xenografts in nude mice were established by subcutaneous injection of cancer cells. Results: Mitogen activated protein kinase 1 (MAPK1) was significantly up-regulated, while miR-422a was down-regulated in thyroid cancer cells cultured with high iodine; miR-422a directly bound to the 3’UTR of MAPK1 mRNA. Moreover, miR-422a negatively regulated MAPK1 expression, and down-regulated miR-422a promoted proliferation and migration of TPC-1 cells. In vivo studies also confirmed that iodine promoted tumor growth by suppressing miR-422a and up-regulating MAPK1. Conclusions: Our study illustrates a new pathway comprising iodine, miRNA and MAPK1, and defines a novel mechanism in thyroid cancer.

PP75. DROSOPHILA MELANOGASTER AS A MODEL ORGANISM TO STUDY GLIOMA: LOCATION AND IDENTIFICATION OF FOLLISTATIN

Gliomas are the most common, malignant brain tumour found in the central nervous system. The main characteristics of gliomas is their rapid proliferation, resistance to current chemotherapies and their ability to infiltrate the brain. Brain tumours have a low survival rate due to the lack of available treatments. In the UK between 2010 and 2011, the survival rate was 14% for 10 or more year. The mortality rates for malignant brain and CNS tumours have increased by up to 24% in the UK between 1970 and 2012. As there is difficulty obtaining glioma samples, it is important to identify a suitable model organism. The main signalling pathways seen to be activated in human glioma development are the epithelial growth factor receptor (EGFR) and phosphatidylinositol-3 kinase (PI3K) pathways. The homologous EFGR and PI3K pathways have been studied greatly in drosophila, and show that there must be co-activation of the EGFR and PI3K pathways for cancer development to occur; leading to an increase in glial cell numbers by 50-100x fold. Follistatin is a protein which has been identified as a biomarker in malignant gliomas; by comparing normal serum to glioma serum it has shown that there is an overexpression of follistatin. Gliomas can be replicated in drosophila as there has been a high level of homology identified in human diseased states and in neural development. Follistatin studies have shown it has important roles in development and differentiation of tissues and organs. It acts as an inhibitor, binding to activin, bone morphogenetic proteins and other proteins which can be found in vertebrates. Follistatin has been identified within a number of different cancer types (such as prostate and ovarian), and plays an important role in cancer metastasis and angiogenesis. Serum studies have revealed follistatin is present in the early stages of cancer development; however the location and role of follistatin in cancer development has not been identified. Drosophila contain a homolog of follistatin, which will allow studies of follistatin in cancer within drosophila. By using drosophila as a model organism it will allow the location of follistatin and its involvement in glioma development to be identified. Immunohistochemistry is used to identify the location and distribution of a protein within a tissue or an organ. It is commonly used to identify which proteins are present in specific types of cancer. Follistatin has been identified to play a role in the early stages of glioma development. Therefore by using immunohistochemistry follistatin can be identified throughout the different stages of glioma development and possibly identify its role in this development. The aim of the research is to identify and locate the protein follistatin in drosophila by using immunohistochemistry. Using different larval instar stages, this will identify the distribution of follistatin in different stages of neural development. The hypothesis would be that follistatin is involved in the early stages of glial development and the distribution is important in glioma development compared to normal neural development.

Biologically Synthesized Gold Nanoparticles using Ocimum sanctum (Tulsi Leaf Extract) Induced Anti-Tumor Response in a T Cell Daltons Lymphoma

The characterizations of green synthesized gold nanoparticles (AuNPs) prepared using Ocimum sanctum leaf extract were done by UV-Spectrophotometer at 500-540 nm. The XRD data obtained were found similar to gold JCPDS File No- 04-0784. SEM and TEM analysis of AuNPs revealed spherical shape and size of 200 nm. Further FT-IR data indicated the various biomolecules present in Ocimum sanctum leaf extract provides stability to gold nanoparticles synthesis. The AuNPs were studied for their anti-cancer activity on Dalton’s lymphoma (DL) cells and the results obtained with IC50 value of < 50 ng/ml performed by MTT assay. Further, to confirm anti-tumor potential and the mode of action of the synthesized AuNPs, cell viability assay, nuclear morphology, DNA fragmentation assay, mitochondrial membrane potential (ΔΨm) analysis, and cell cycle analysis were done using DL cells. DL cells treated with the AuNPs showed reduced cell viability, altered nuclear morphology, typical apoptotic DNA ladder formation and apoptosis. From the above finding it can be concluded that the AuNPs have potential to decrease the proliferation of tumor cells and enhanced the production of ROS. Gold nanoparticles used in cancer detection and diagnosis/treatment are mainly in preclinical stages of cancer development.

Emergence of the Noncoding Cancer Genome: A Target of Genetic and Epigenetic Alterations.

The majority of genetic and epigenetic alterations accumulate in the noncoding genome throughout oncogenesis. Discriminating driver from passenger events is a challenge that holds great promise to improve our understanding of the etiology of different cancer types. Advancing our understanding of the noncoding cancer genome may thus identify new therapeutic opportunities and accelerate our capacity to find improved biomarkers to monitor various stages of cancer development. Cancer Discov; 6(11); 1215-29. ©2016 AACR.

Molecular changes in appearance of a cancer cell among normal HEK293T cells

In very early stages of cancer development, one or a few cells expressing cancer-associated genes appear among a much larger number of surrounding normal cells. To analyze the molecular changes induced by this co-existence, we artificially prepared transformed cells with complete loss of tumor suppressor gene, SCRIB, among normal human embryonic kidney (HEK293T) cells. A cell strain with SCRIB-knockout was successfully constructed by using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9 nuclease system and co-cultured with normal cells. By measuring the time-course changes in cell numbers when SCIRB-knockout cells (cancer model) or cells with normal level of SCRIB expression were respectively co-cultured with wild-type normal HEK293T cells, it was shown that the SCRIB-knockout strain was beneficial for proliferation when mixed together with normal cells. Moreover, as a result of proteome analysis on wild-type cells separated from co-culture with SCRIB-knockout cells, a total of 843 proteins were identified, among which 139 proteins were specific. Among the specifically identified proteins, 22 proteins were annotated to be involved in cytoskeletons including microtubule motor activity-associated proteins. It was implied that molecular changes in cytoskeletons occurred in normal cells when co-cultured with SCRIB knockout cells, but the SCRIB knockout might affect proliferation of the transformed cells with SCRIB knockout by defensive or offensive mechanism of surrounding normal cells.

The complexity of integrins in cancer and new scopes for therapeutic targeting.

Cancer is a complex disease and progresses within a dynamically evolving extracellular matrix that controls virtually every aspect of the tumour and tumour-associated cells. Interactions with the extracellular microenvironment are predominately mediated by a family of cell-surface transmembrane receptors called integrins. Integrin–matrix engagement leads to the formation of adhesion plaques, consisting of signalling and adaptor proteins, at the plasma membrane that link the extracellular matrix to the regulation of the cell cytoskeleton. In this review, we will highlight exciting data that identify new roles for integrins and integrin-dependent signalling in cancer away from the plasma membrane, discuss the implications of integrin-dependent regulation of Met and ErbB2 growth factor receptors and highlight the role of specific integrins in different stages of cancer development including maintenance of cancer stem cells.

Satellite RNAs promote pancreatic oncogenic processes via the dysfunction of YBX1.

Highly repetitive tandem arrays at the centromeric and pericentromeric regions in chromosomes, previously considered silent, are actively transcribed, particularly in cancer. This aberrant expression occurs even in K-ras-mutated pancreatic intraepithelial neoplasia (PanIN) tissues, which are precancerous lesions. To examine the biological roles of the satellite RNAs in carcinogenesis, we construct mouse PanIN-derived cells expressing major satellite (MajSAT) RNA and show increased malignant properties. We find an increase in frequency of chromosomal instability and point mutations in both genomic and mitochondrial DNA. We identify Y-box binding protein 1 (YBX1) as a protein that binds to MajSAT RNA. MajSAT RNA inhibits the nuclear translocation of YBX1 under stress conditions, thus reducing its DNA-damage repair function. The forced expression of YBX1 significantly decreases the aberrant phenotypes. These findings indicate that during the early stage of cancer development, satellite transcripts may act as ‘intrinsic mutagens' by inducing YBX1 dysfunction, which may be crucial in oncogenic processes.

Human Colorectal Cancer Stage-dependent Global DNA Hypomethylation of Cancer-associated Fibroblasts.

Cancer-associated fibroblasts (CAFs) play an important role in tumor development and progression. The prevailing consensus favors the view that a specific epigenetic signature underpins the stable CAF phenotype. The aim of the present study was to assess global DNA methylation in CAFs during the adenoma-carcinoma sequence in non-familial sporadic human colorectal cancer (CRC). Immunohistochemical staining of nuclear 5-methylcytosine (5'-meCyt) was performed in matched samples of colonic tumor tissue and normal colonic mucosa excised from six patients with adenomas and four with adenocarcinomas. The staining intensity was expressed semi-quantitatively as the immunohistochemical staining score (ISS). ISS values of human colonic CAFs and adenomatous samples were 14.00±2.2 and 14.08±1.8, respectively, showing no statistically significant difference. In contrast, a marked trend was found towards global DNA hypomethylation in CAFs from adenocarcinomatous specimens compared to matched normal mucosa: ISS: 9.25±2.44 (range=6-11) vs. 16.17±0.75, respectively, p<0.03. Final stages of cancer development in CRC are associated with global DNA hypomethylation in stromal CAFs.

Abstract 3844: A novel liposomal Clodronate depletes tumor-associated macrophages in primary and metastatic melanoma: anti-angiogenic and anti-tumor effects

Abstract The depletion of tumor-associated macrophages (TAMs), involved in different stages of cancer development and progression, is an appealing strategy in cancer therapy. We developed novel Clodronate-containing liposomes (Clo-Lipo-DOTAP) presenting good physicochemical properties (size distribution, polidispersity index and Z-potential). In vitro, Clo-Lipo-DOTAP inhibited proliferation, reduced viability and induced apoptosis of a macrophage-like cell line in a dose- and time-dependent manner. In proof of functionality experiments, Clo-Lipo-DOTAP depleted macrophages in a genetic mouse model of chronic hepatitis and hepatocellular carcinoma leading to a significant reduction of F4/80-positive cells in the liver and spleen of treated mice compared to PBS-treated controls. The number of granulocytes, B and T lymphocytes was not affected. In B16/F10 subcutaneous melanoma-bearing mice, Clo-Lipo-DOTAP significantly reduced the volume of primary tumors (P &amp;lt; 0.001). Within the tumors, the expression F4/80 and α-SMA was significantly lowered. Plasma levels of IL-10, Mo KC, TNF-α, VEGF and PDGF-bb were statistically decreased. In B16/F10 lung metastatic melanoma model, treatment with Clo-Lipo-DOTAP significantly reduced the number of pulmonary nodules (P &amp;lt; 0.05). F4/80-positive cells and microvessel density were statistically decreased. In conclusion, the depletion of TAMs in primary and metastatic melanoma presents anti-tumor efficacy via inhibition of angiogenesis and modulation of inflammation related cytokines. Citation Format: Chiara Brignole, Patrizia Perri, Francesca Piaggio, Fabio Pastorino, Daniela Di Paolo, Laura Emionite, Antonio Daga, Vangelis Kondylis, Manolis Pasparakis, Domenico Ribatti, Mirco Ponzoni. A novel liposomal Clodronate depletes tumor-associated macrophages in primary and metastatic melanoma: anti-angiogenic and anti-tumor effects. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3844.

Abstract 962: Deregulated transcription of mouse satellite sequences accelerates oncogenic processes via functional inhibition of YBX1 protein

Abstract Highly repetitive tandem arrays located at centromere and pericentromere regions of the chromosomes had been considered epigenetically silent by heterochromatin modification. However, the deregulated transcription of the non-coding satellite sequences exists in human and mouse pancreatic cancer tissues. This aberrant expression can be detected even in Kras-mutated pancreatic intraepithelial neoplasia (PanIN) tissues, which are pre-cancerous lesions to invasive pancreatic cancer. To examine the biological roles of these aberrantly expressed satellite RNAs during the carcinogenesis steps, we established genetically-modified mouse PanIN-derived cells, in which mouse major satellite (MajSAT) RNAs were ectopically expressed. MajSAT RNA expressing PanIN-derived cells showed the increased chromosomal instability and the rate of spontaneous point mutations in the genomic as well as in the mitochondrial DNAs. We identified YBX1 protein as a binding protein specifically with MajSAT RNA by RNA immunoprecipitation. MajSAT RNA inhibited nuclear translocation of YBX1 under oxidative damage, which reduced the DNA damage repair activity of YBX1. The mutation rate of genomic and mitochondrial DNAs, and transformation rate were rescued by YBX1 overexpression in these cells. These findings indicate that satellite transcripts at the early stage of cancer development may act as “mutagens” and accelerate oncogenic processes. Citation Format: Takahiro Kishikawa, Motoyuki Otsuka, Kazuhiko Koike. Deregulated transcription of mouse satellite sequences accelerates oncogenic processes via functional inhibition of YBX1 protein. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 962.

Impaired lymphatic function accelerates cancer growth.

Increased lymphangiogenesis is a common feature of cancer development and progression, yet the influence of impaired lymphangiogenesis on tumor growth is elusive. C3HBA breast cancer and KHT-1 sarcoma cell lines were implanted orthotopically in Chy mice, harboring a heterozygous inactivating mutation of vascular endothelial growth factor receptor-3, resulting in impaired dermal lymphangiogenesis. Accelerated tumor growth was observed in both cancer models in Chy mice, coinciding with reduced peritumoral lymphangiogenesis. An impaired lymphatic washout was observed from the peritumoral area in Chy mice with C3HBA tumors, and the number of macrophages was significantly reduced. While fewer macrophages were detected, the fraction of CD163+ M2 macrophages remained constant, causing a shift towards a higher M2/M1 ratio in Chy mice. No difference in adaptive immune cells was observed between wt and Chy mice. Interestingly, levels of pro- and anti-inflammatory macrophage-associated cytokines were reduced in C3HBA tumors, pointing to an impaired innate immune response. However, IL-6 was profoundly elevated in the C3HBA tumor interstitial fluid, and treatment with the anti-IL-6 receptor antibody tocilizumab inhibited breast cancer growth. Collectively, our data indicate that impaired lymphangiogenesis weakens anti-tumor immunity and favors tumor growth at an early stage of cancer development.

TP53 mutation at early stage of colorectal cancer progression from two types of laterally spreading tumors.

Although most sporadic colorectal cancers (CRC) are thought to develop from protruded adenomas through the adenoma–carcinoma sequence, some CRC develop through flat lesions, so‐called laterally spreading tumors (LST). We previously analyzed epigenetic aberrations in LST and found that LST are clearly classified into two molecular subtypes: intermediate‐methylation with KRAS mutation and low‐methylation with absence of oncogene mutation. Intermediate‐methylation LST were mostly granular type LST (LST‐G) and low‐methylation LST were mostly non‐granular LST (LST‐NG). In the present study, we conducted a targeted exon sequencing study including 38 candidate CRC driver genes to gain insight into how these genes modulate the development of LST. We identified a mean of 11.5 suspected nonpolymorphic variants per sample, including indels and non‐synonymous mutations, although there was no significant difference in the frequency of total mutations between LST‐G and LST‐NG. Genes associated with RTK/RAS signaling pathway were mutated more frequently in LST‐G than LST‐NG (P = 0.004), especially KRAS mutation occurring at 70% (30/43) of LST‐G but 26% (13/50) of LST‐NG (P < 0.0001). Both LST showed high frequency of APC mutation, even at adenoma stage, suggesting its involvement in the initiation stage of LST, as it is involved at early stage of colorectal carcinogenesis via adenoma‐carcinoma sequence. TP53 mutation was never observed in adenomas, but was specifically detected in cancer samples. TP53 mutation occurred during development of intramucosal cancer in LST‐NG, but during development of cancer with submucosal invasion in LST‐G. It is suggested that TP53 mutation occurs in the early stages of cancer development from adenoma in both LST‐G and LST‐NG, but is involved at an earlier stage in LST‐NG.

An ontogenetic approach to gynecologic malignancies.

Ontogenetic anatomy is the mapping of body compartments established during early embryologic development, particularly well demarcated in the adult pelvis. Traditional cancer surgery is based on wide tumour excision with a safe margin, whereas the ontogenetic theory of local tumour spread claims that local dissemination is facilitated in the ontogenetic compartment of origin, but suppressed at its borders in the early stages of cancer development. Optimal local control of cancer is achieved by whole compartment resection with intact margins following ontogenetic “planes”. The principles embodied in this hypothesis are most convincingly supported by the results of the implementation of total mesorectal excision in rectal cancer, and more recently, by innovative surgical approaches to gynaecologic malignancies. The high resolution contrast of MR, accurately delineating pelvic fascial compartments, makes it the best imaging modality for gynaecologic cancer surgery planning following these principles, but requires interpretation of imaging anatomy from a different perspective.Teaching Points• Ontogenetic anatomy refers to mapping of embryologically determined body compartments.• Ontogenetic theory claims tumour growth is not isometrical, but rather compartment permissive.• Ontogenetic principles are highly supported by the outcome results of total mesorectal excision.• Innovative gynaecologic cancer surgery approaches based on ontogenetic theory show promising results.