Colorectal Tumor Cells Research Articles

Increased Levels of Oxidative Damage in Liver Metastases Compared with Corresponding Primary Colorectal Tumors: Association with Molecular Subtype and Prior Treatment

High levels of oxidative stress in disseminated colorectal cancer tumor cells may form a therapeutically exploitable vulnerability. However, it is unclear whether oxidative stress and damage persist in metastases. Therefore, we analyzed markers of oxidative damage in primary colorectal tumors and their corresponding liver metastases. Markers of generic and oxidative DNA damage [phosphorylated histone H2AX (γH2AX) and 8-hydroxy-2'-deoxyguanosine (8-OHdG)] were significantly higher in liver metastases compared with their corresponding primary tumors. Chemotherapy and/or radiotherapy before tumor resection was associated with increased persistent oxidative DNA damage, and this effect was more pronounced in metastases. Immunohistochemistry-based molecular classification into epithelial- and mesenchymal-like molecular subtypes revealed that untreated mesenchymal-like tumors contained lower levels of oxidative DNA damage compared with epithelial-like tumors. Treated mesenchymal-like tumors, but not epithelial-like tumors, showed significantly higher levels of γH2AX and 8-OHdG. Mesenchymal-like tumors expressed significantly lower levels of phosphorylated nuclear factor erythroid 2-related factor2, a master regulator of the antioxidant response, and nuclear factor erythroid 2-related factor 2-controlled genes. Of interest, a positive 8-OHdG status identified a subgroup of mesenchymal-like metastases with a poor overall survival. An increased capacity to tolerate therapy-induced oxidative damage in mesenchymal-like colorectal cancer may explain, at least in part, the poor responsiveness of these tumors to chemotherapy, which could contribute to the poor survival of this patient subgroup.

Abstract 2552: Preclinical development of T-cell receptor therapy targeting the 5T4 tumor antigen on renal cell carcinoma

Abstract Purpose: The cancer-testis tumor antigen 5T4 is expressed on ~ 95% of primary RCC tumors as well as a variety of other tumor types but not on healthy tissue. Consequently, 5T4 has been targeted by antibody and vaccine therapies in cancer patients. Our group has previously isolated high-avidity human CD8+ T-cell clones specific for 5T417-25 and HLA-A2 that are capable of recognizing RCC tumor in vitro and as a murine xenograft. These clones provide the source for T-cell receptor alpha (TRA) and beta (TRB) genes to develop engineered T cells with re-directed cytotoxic specificity for tumors expressing the 5T4 antigen. Experimental Procedures: Targeted single-cell RNA-seq was performed on 5T417-25 specific T-cell clones to sequence the highly variable complementarity-determining region 3 (CDR3) of TRA and TRB genes. Full length 5T417-25 specific TRA and TRB sequences were then re-constructed and modified by codon optimization and introduction of transmembrane domain cys-cys covalent crosslinking to augment correct alpha and beta chain pairing. TRA and TRB genes were cloned into third generation lentiviral vectors and transduced into CD8+ T cells from healthy donors. Re-directed effector function for target cells expressing 5T4 was measured by chromium release assay and IFN-gamma ELISA. CRISPR/Cas9 gene editing techniques to augment effector activity of engineered T cells by suppressing native TCR expression and disrupting inhibitory co-receptor genes for PD-1, LAG-3, or TIM-3, are also under development. Results: Seven unique TRA-TRB pairs were identified from a panel of 38 5T417-25 specific CD8+ T cell clones. Lentiviral mediated expression of all seven 5T417-25 specific TCR transgene constructs was detectable by 5T417-25/HLA-A2 tetramer immunostaining with transduction efficiency from 30% to 80%. 5T4-TCR transduced CD8+ T cells demonstrated re-directed cytotoxic activity to 5T4+/HLA-A2+ RCC, breast, and colorectal tumor cells, but not to 5T4-/HLA-A2+ normal cells. CRISPR/Cas9 targeting of a conserved sequence in the native TRA constant region was sufficient to suppress native TCR expression on polyclonal CD8+ T cells derived from healthy donors. Characterization of the proliferation kinetics, differentiation phenotypes and effector functions of 5T4-TCR transduced T cells modified by gene editing inhibition of native TRA or inhibitory co-receptors (PD-1, LAG-3 or TIM-3) is ongoing. Conclusions: Transgenic T cell products can be re-directed to recognize a broadly shared epitope of the 5T4 tumor antigen and to kill 5T4+ tumor lines in vitro. Further augmentation of effector activity and specificity by CRISPR/Cas9 gene editing techniques is a developmental priority. Transgenic 5T4-reactive T cells are of interest for future testing as a therapeutic cellular immunotherapy product in patients with 5T4+ tumors. Citation Format: Yuexin Xu, Alicia J. Morales, Michael J. Cargill, Andrea Towlerton, Edus H. Warren, Scott S. Tykodi. Preclinical development of T-cell receptor therapy targeting the 5T4 tumor antigen on renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2552.

Abstract DDT02-05: eFT226: A selective and highly potent inhibitor of eukaryotic initiation factor 4A (eIF4A), a novel approach for the treatment of cancer

Abstract eFT226: A Selective and Highly Potent Inhibitor of Eukaryotic Initiation Factor 4A (eIF4A), a Novel Approach for the Treatment of Cancer Siegfried H Reich, Peggy A Thompson, Justin T Ernst, Boreth Eam, Nathan P Young, Sarah Fish, Joan Chen, Maria Barrera, Haleigh Howard, Ana Parra, Eric Sung, Jocelyn Staunton, Ivy NJ Hung, Gregory S Parker, Gary G Chiang, Christopher J Wegerski, Andres Nevarez, Jeff Clarine, Samuel Sperry, Alan Xiang, Chinh Tran, Christian Nilewski, Garrick K Packard, Theodore Michels, Paul A Sprengeler, and Kevin R Webster Effector Therapeutics, San Diego, CA Oncoprotein expression is tightly controlled at the level of RNA translation which is largely regulated by the eukaryotic translation initiation factor 4F (eIF4F). eIF4A1, a component of the eIF4F complex, catalyzes the ATP dependent unwinding of RNA duplexes and facilitates 43S ribosome complex scanning within the 5'-untranslated region (UTR). eIF4A1 is required for efficient translation of key oncogenes that contain complex secondary structures within the 5'-UTR. eFT226 is a novel, potent and selective eIF4A small molecule inhibitor with excellent physicochemical and pharmaceutical properties. The design of eFT226 involved ab initio ligand-based methods coupled with small molecule crystal structure analysis. eFT226 inhibits eIF4A1 through a reversible sequence-selective enhancement of eIF4A1 binding to mRNA with specific polypurine motifs within the 5'-UTR. The formation of a stable ternary complex [eIF4A1/eFT226/mRNA] with specific sequence recognition motifs leads to a block in ribosome scanning of select mRNAs. Treatment of lymphoma, AML, breast, colorectal, lung and hepatocellular tumor cell lines with eFT226 led to a dose dependent translational down regulation (IC50 of ~5-20 nM) of key oncogenes that drive tumor cell survival and proliferation (i.e., c-MYC, CCND1, BCL2 and MCL-1). Oncogene down regulation results in potent inhibition of cellular proliferation (GI50 of ~2-30 nM) across a panel of tumor cell lines. Enhanced anti-tumor sensitivity and a rapid induction of apoptosis was observed in hematological cell lines including lymphoma and AML. Inhibition of tumor cell proliferation and survival with eFT226 treatment results in significant antitumor activity in vivo in multiple human tumor models of DLBCL, Burkitt's lymphoma, acute myeloid leukemia (AML), and solid tumors following ≤ 1 mg/kg/week IV administration. eFT226 regulates the protein expression of multiple metabolic markers (i.e. c-MYC, HK2, TXNIP and GLUT1) that result in inhibition of tumor glucose uptake supporting the use of 18F-FDG-PET imaging as a measure of eFT226 target engagement in the clinic. These data demonstrate that eFT226 is a sequence-selective translational repressor of key oncogenic drivers that are essential for tumor cell proliferation and survival and support the clinical development of eFT226 in cancer patients. Citation Format: Siegfried H. Reich, Peggy A. Thompson, Justin T. Ernst, Boreth Eam, Nathan P. Young, Sarah Fish, Joan Chen, Maria Barrera, Haleigh Howard, Ana Parra, Eric Sung, Jocelyn Staunton, Ivy Nj Hung, Gregory S. Parker, Gary G. Chiang, Christopher J. Wegerski, Andres Nevarez, Jeff Clarine, Samuel Sperry, Alan Xiang, Chinh Tran, Christian Nilewski, Garrick K. Packard, Theodore Michels, Paul A. Sprengeler, Kevin R. Webster. eFT226: A selective and highly potent inhibitor of eukaryotic initiation factor 4A (eIF4A), a novel approach for the treatment of cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr DDT02-05.

Cytotoxic Effects of Lactobacilli Isolated from Azerbaijan Traditional Cheeses on Colorectal Tumor Cells HCT 116 and Identification of Paramount Strains

Cytotoxic Effects of Lactobacilli Isolated from Azerbaijan Traditional Cheeses on Colorectal Tumor Cells HCT 116 and Identification of Paramount Strains

Abstract 2365: A chemical genetics approach identifies PTP4A3 as a regulator of colon cancer cell adhesion

Abstract Dysregulation of the tightly controlled protein phosphorylation networks that govern cellular behavior causes cancer. The membrane-associated, intracellular protein tyrosine phosphatase PTP4A3 is overexpressed in human colorectal cancer and contributes to cell migration and invasion. To interrogate further the role of PTP4A3 in colorectal cancer cell migration and invasion, we deleted the Ptp4a3 gene from murine colorectal tumor cells. The resulting PTP4A3-/- cells exhibited impaired colony formation, spheroid formation, migration, and adherence compared to the isogenic PTP4A3fl/fl cells. We replicated these phenotypic changes using the new small molecule allosteric PTP4A3 inhibitor, JMS-053. A related structure, JMS-038, which lacked phosphatase inhibition, displayed no cellular activity. Reduction in cell viability and colony formation by JMS-053 occurred in both mouse and human colorectal cell lines and required PTP4A3 expression. Ptp4a3 deletion increased the expression of extracellular matrix and adhesion genes, including the tumor suppressor Emilin 1. JMS-053 also increased Emilin 1 gene expression. Moreover, the human TCGA genomic database revealed colorectal tumors with high Ptp4a3 expression had low Emilin1 expression. These chemical and biological reagents reveal a previously unknown communication between the intracellular PTP4A3 phosphatase and the extracellular matrix and support efforts to pharmacologically target PTP4A3. Citation Format: Kelley E. McQueeney, Joseph M. Salamoun, Jennifer Ahn, Paula Pekic, Isabella K. Blanco, Heather Struckman, Elizabeth R. Sharlow, Peter Wipf, John S. Lazo. A chemical genetics approach identifies PTP4A3 as a regulator of colon cancer cell adhesion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2365.

Zika Virus Selectively Kills Aggressive Human Embryonal CNS Tumor Cells In Vitro and In Vivo.

Zika virus (ZIKV) is largely known for causing brain abnormalities due to its ability to infect neural progenitor stem cells during early development. Here, we show that ZIKV is also capable of infecting and destroying stem-like cancer cells from aggressive human embryonal tumors of the central nervous system (CNS). When evaluating the oncolytic properties of Brazilian Zika virus strain (ZIKVBR) against human breast, prostate, colorectal, and embryonal CNS tumor cell lines, we verified a selective infection of CNS tumor cells followed by massive tumor cell death. ZIKVBR was more efficient in destroying embryonal CNS tumorspheres than normal stem cell neurospheres. A single intracerebroventricular injection of ZIKVBR in BALB/c nude mice bearing orthotopic human embryonal CNS tumor xenografts resulted in a significantly longer survival, decreased tumor burden, fewer metastasis, and complete remission in some animals. Tumor cells closely resembling neural stem cells at the molecular level with activated Wnt signaling were more susceptible to the oncolytic effects of ZIKVBR Furthermore, modulation of Wnt signaling pathway significantly affected ZIKVBR-induced tumor cell death and viral shedding. Altogether, these preclinical findings indicate that ZIKVBR could be an efficient agent to treat aggressive forms of embryonal CNS tumors and could provide mechanistic insights regarding its oncolytic effects.Significance: Brazilian Zika virus strain kills aggressive metastatic forms of human CNS tumors and could be a potential oncolytic agent for cancer therapy. Cancer Res; 78(12); 3363-74. ©2018 AACR.

PO-121 ALK dependant phosphoproteome and gene expression profiling of neuroblastoma cells

IntroductionThe calcium-sensing receptor (CaSR) is a heterotrimeric G protein-coupled receptor that was firstly identified as a key regulator of Ca++ homeostasis in the blood. Ubiquitously expressed in the body, the CaSR controls also cell proliferation, differentiation and apoptosis. In colorectal cancer the CaSR slows cell proliferation and induces apoptosis, however, it is down-regulated during tumorigenesis due to unclear mechanisms. Moreover, a common view on CaSR localization within normal intestinal crypts is still missing.We hypothesise that restoring CaSR expression inhibits tumour progression. Therefore, it is of paramount importance to understand the mechanisms that regulate CaSR expression in normal colonic epithelia and in tumours.Our aim is to find ways to restore CaSR expression by inducing differentiation in colonic organoids.Material and methodsWe used a 3D cell culture methodology, culturing colon organoids in matrigel. The organoids were generated extracting colonic crypts from the intestine of the mice and were kept in standard stem cell media to guarantee stem cell poll.We induced lineage-specific differentiation of colonic organoids either into enterocytes or goblet cells by altering the composition of the culturing media. We assessed CaSR expression by RT-qPCR and immunofluorescence, testing also specific differentiation markers such as FABP2 for enterocytes and MUC2 for goblet cells.Results and discussionsOur preliminary data showed that the CaSR was not expressed in the organoids cultured in stem cell media where even the differentiation markers were barely detectable. On the other hand, organoids cultured for 7 days in enterocyte-specific differentiating condition expressed both CaSR and FABP2, while in goblet cells CaSR expression remained undetectable. Our results not only show that inducing differentiation leads to higher CaSR levels, but also suggest that the CaSR is expressed in enterocytes rather than MUC2-expressing goblet cells.ConclusionWe conclude that, like poorly differentiated colorectal tumour cells, the colonic stem cells do not express the CaSR, which is expressed in mature intestinal cells. Further experiments will allow us to undoubtedly determine in which subtypes of differentiated cells the CaSR is preferentially localised.

Cancer stem cells in colorectal tumors of various extents.

e15659Background: The purpose of the study was to assess an association between the tumor invasion and levels of cancer stem cells (CD44+ and CD133+) in colorectal cancer. Methods: The study includ...

Spatial mutation patterns as markers of early colorectal tumor cell mobility.

A growing body of evidence suggests that a subset of human cancers grows as single clonal expansions. In such a nearly neutral evolution scenario, it is possible to infer the early ancestral tree of a full-grown tumor. We hypothesized that early tree reconstruction can provide insights into the mobility phenotypes of tumor cells during their first few cell divisions. We explored this hypothesis by means of a computational multiscale model of tumor expansion incorporating the glandular structure of colorectal tumors. After calibrating the model to multiregional and single gland data from 19 human colorectal tumors using approximate Bayesian computation, we examined the role of early tumor cell mobility in shaping the private mutation patterns of the final tumor. The simulations showed that early cell mixing in the first tumor gland can result in side-variegated patterns where the same private mutations could be detected on opposite tumor sides. In contrast, absence of early mixing led to nonvariegated, sectional mutation patterns. These results suggest that the patterns of detectable private mutations in colorectal tumors may be a marker of early cell movement and hence the invasive and metastatic potential of the tumor at the start of the growth. In alignment with our hypothesis, we found evidence of early abnormal cell movement in 9 of 15 invasive colorectal carcinomas ("born to be bad"), but in none of 4 benign adenomas. If validated with a larger dataset, the private mutation patterns may be used for outcome prediction among screen-detected lesions with unknown invasive potential.

A chemical genetics approach identifies PTP4A3 as a regulator of colon cancer cell adhesion.

Dysregulation of the tightly controlled protein phosphorylation networks that govern cellular behavior causes cancer. The membrane-associated, intracellular protein tyrosine phosphatase PTP4A3 is overexpressed in human colorectal cancer and contributes to cell migration and invasion. To interrogate further the role of PTP4A3 in colorectal cancer cell migration and invasion, we deleted the Ptp4a3 gene from murine colorectal tumor cells. The resulting PTP4A3-/- cells exhibited impaired colony formation, spheroid formation, migration, and adherence compared with the paired PTP4A3fl/fl cells. We replicated these phenotypic changes using the new small-molecule, allosteric PTP4A3 inhibitor JMS-053. A related structure, JMS-038, which lacked phosphatase inhibition, displayed no cellular activity. Reduction in cell viability and colony formation by JMS-053 occurred in both mouse and human colorectal cell lines and required PTP4A3 expression. Ptp4a3 deletion increased the expression of extracellular matrix (ECM) and adhesion genes, including the tumor suppressor Emilin 1. JMS-053 also increased Emilin 1 gene expression. Moreover, The Cancer Genome Atlas genomic database revealed human colorectal tumors with high Ptp4a3 expression had low Emilin 1 expression. These chemical and biologic reagents reveal a previously unknown communication between the intracellular PTP4A3 phosphatase and the ECM and support efforts to pharmacologically target PTP4A3.-McQueeney, K. E., Salamoun, J. M., Ahn J. G., Pekic, P., Blanco, I. K., Struckman, H. L., Sharlow, E. R., Wipf, P., Lazo, J. S. A chemical genetics approach identifies PTP4A3 as a regulator of colon cancer cell adhesion.

Cyclin-dependent kinase 1 targeting improves sensitivity to radiation in BRAF V600E colorectal carcinoma cells.

Preoperative chemoradiation is currently the standard of care in locally advanced rectal carcinoma, even though a subset of rectal tumors does not achieve major clinically meaningful responses upon neoadjuvant chemoradiation. At present, no molecular biomarkers are available to predict response to neoadjuvant chemoradiation and select resistant tumors willing more intense therapeutic strategies. Thus, BRAF mutational status was investigated for its role in favoring resistance to radiation in colorectal carcinoma cell lines and cyclin-dependent kinase 1 as a target to improve radiosensitivity in BRAF V600E colorectal tumor cells. Colony-forming assay and apoptotic rates were evaluated to compare the sensitivity of different colon carcinoma cell lines to ionizing radiation and their radiosensitivity upon exposure to BRAF and/or cyclin-dependent kinase 1 inhibitory/silencing strategies. Cyclin-dependent kinase 1 expression/subcellular distribution was studied by immunoblot analysis. Colon carcinoma BRAF V600E HT29 cells exhibited poor response to radiation compared to BRAF wild-type COLO320 and HCT116 cells. Interestingly, neither radiosensitizing doses of 5-fluoruracil nor BRAF inhibition/silencing significantly improved radiosensitivity in HT29 cells. Of note, poor response to radiation correlated with upregulation/relocation of cyclin-dependent kinase 1 in mitochondria. Consistently, cyclin-dependent kinase 1 inhibition/silencing as well as its targeting, through inhibition of HSP90 quality control pathway, significantly inhibited the clonogenic ability and increased apoptotic rates in HT29 cells upon exposure to radiation. These data suggest that BRAF V600E colorectal carcinoma cells are poorly responsive to radiation, and cyclin-dependent kinase 1 represents a target to improve radiosensitivity in BRAF V600E colorectal tumor cells.

Extracellular DNA promotes colorectal tumor cell survival after cytotoxic chemotherapy

BackgroundInflammation promotes the growth and survival of malignant cells. Inflammation within the tumor microenvironment is a result of damage-associated molecular patterns released by dead or dying cells that provide survival signals to the surrounding cells. It has been proposed that extracellular DNA can act as a damage-associated molecular pattern given the association between circulating DNA and autoimmune diseases. Herein, we demonstrate a novel role for genomic extracellular DNA binding to the Toll-like receptor (TLR)-9 on tumor cells in response to cytotoxic insult. Materials and methodsThe colorectal tumor cell line HCCT116 was used to study the role of DNA in tumor cell response to chemotherapy. Cell viability was assessed using CCK-8 assay. Cell death mechanisms were assessed by YOYO-1 and lactate dehydrogenase staining for necrosis and TUNEL staining for apoptosis. Autophagy was measured by LC3 punctate formation. TLR9-short hairpin RNA was used to knockdown TLR-9 and determine its role in tumor cell response to DNA. ResultsDNA is released from necrotic tumor cells after chemotherapy. Survival after cytotoxic insult is enhanced by the presence of extracellular DNA as a result of inhibition of apoptosis and enhanced autophagy. Knockdown of TLR-9 enhanced apoptosis, diminished autophagy, and decreased survival after cytotoxic insult in the presence or absence of extracellular DNA. ConclusionsDNA in the tumor microenvironment promotes survival through induction of autophagy via TLR-9 signaling. This work has important implications for targeting extracellular DNA, TLR-9, and autophagy during treatment with chemotherapy and enhances our understanding of the role of extracellular DNA in the tumor microenvironment.

EYA1 promotes tumor angiogenesis by activating the PI3K pathway in colorectal cancer

Blood vessels are one of the major routes for the dissemination of cancer cells. Malignant tumors release growth factors such as vascular endothelial growth factor(VEGF) to induce angiogenesis, thereby promoting metastasis. Here, we report that The Drosophila Eyes Absent Homologue 1 (EYA1), which is overexpressed in colorectal tumor cells, can promote colorectal tumor angiogenesis by coordinating with the hypoxia-inducible factor 1 (HIF-1α) to increase the expression of VEGF-A. Moreover, data indicated that the enhancement of HIF-1α expression by Eya1 depended on its ability to activate the phosphatidylinositol 3-kinase (PI3K) signaling pathways to increase the phosphorylation of AKT subunits. Overexpression of Eya1 increased tumor angiogenesis in vivo and in vitro. Our study suggested that Eya1 is essential in regulating cancer cell-mediated angiogenesis and contributes to tumor growth, and that Eya1 provides a potential and specific target for new anti-angiogenesis drug development.

Activated human primary NK cells efficiently kill colorectal cancer cells in 3D spheroid cultures irrespectively of the level of PD-L1 expression

ABSTRACT Haploidentical Natural Killer (NK) cells have been shown as an effective and safe alternative for the treatment of haematological malignancies with poor prognosis for which traditional therapies are ineffective. In contrast to haematological cancer cells, that mainly grow as single suspension cells, solid carcinomas are characterised by a tridimensional (3D) architecture that provide specific surviving advantages and resistance against chemo- and radiotherapy. However, little is known about the impact of 3D growth on solid cancer immunotherapy especially adoptive NK cell transfer. We have recently developed a protocol to activate ex vivo human primary NK cells using B lymphoblastic cell lines, which generates NK cells able to overcome chemoresistance in haematological cancer cells. Here we have analysed the activity of these allogeneic NK cells against colorectal (CRC) human cell lines growing in 3D spheroid culture and correlated with the expression of some of the main ligands regulating NK cell activity. Our results indicate that activated NK cells efficiently kill colorectal tumour cell spheroids in both 2D and 3D cultures. Notably, although 3D CRC cell cultures favoured the expression of the inhibitory immune checkpoint PD-L1, it did not correlate with increased resistance to NK cells. Finally, we have analysed in detail the infiltration of NK cells in 3D spheroids by microscopy and found that at low NK cell density, cell death is not observed although NK cells are able to infiltrate into the spheroid. In contrast, higher densities promote tumoural cell death before infiltration can be detected. These findings show that highly dense activated human primary NK cells efficiently kill colorectal carcinoma cells growing in 3D cultures independently of PD-L1 expression and suggest that the use of allogeneic activated NK cells could be beneficial for the treatment of colorectal carcinoma.

A novel 3-dimensional (3D) microfluidics device to model the tumor microenvironment (TME).

704 Background: In vitro models of cancer have led to significant therapeutic advances. Despite the widespread use of in vitro tissue culture, the ability to directly evaluate human biology is limited by the inability to model the complex, 3D nature of the TME. We introduce a novel, microfluidic-based system of 3D human micro-tumors perfused with a network of human micro-vessels which could overcome the shortcomings of current in vitro systems. Methods: The micro-device was created by casting polydimethylsiloxane (PDMS) onto master molds, which are then bonded to a flat PDMS sheet using air plasma. Normal human lung fibroblasts (NHLF) and GFP labelled endothelial colony forming cell derived endothelial cells (EC-FCECs) were loaded in a fibrin gel at a 1:2 ratio into the central tissue chamber. Media was introduced through the microfluidic lines. The vascular network was developed with complete EGM2 media under nominal interstitial flow. Colorectal tumor cell lines labelled with mCherry were loaded to the side chambers on the seventh day after NHLF and EC loading. Bevacizumab or TGF- β were added on the second day after tumor cell loading. Results: Micro-vessels formed in the central chamber in 5-7 days after loading. The vessels were perfused with 70KDa fluorescent (red) dextran, and displayed intact vessel wall barrier. A suspension of a colorectal tumor cell line was loaded into the device side chambers, next to a fully developed vasculature. The tumor cells drove angiogenesis into the side chambers, and at the same time tumor began to migrate into the central chamber and within the vessel lumen. The angiogenesis induced by tumor cells can be pharmacologically inhibited, and the migration/ intravasation of tumor cells can be stimulated by TGF-β. Conclusions: Our novel micro-device system can be used as a functional in vitro system that can model the tumor micro-environment. This system has the advantage over current in vitro and in vivo systems in that it is high-throughput, rapid, cost-effective, and recreates many features of the 3D TME. We are currently expanding the platform to incorporate immune cells and designing a completely autologous system to test cancer immunotherapeutics.

A Co-culture Method to Investigate the Crosstalk Between X-ray Irradiated Caco-2 Cells and PBMC.

The protocol adopted in this work aims at unraveling how X-rays perturb the functioning of the intestinal barrier, focusing on the interplay between colorectal tumor cells and the immune system. Colorectal carcinoma is among the most common type of cancer, typically treated by surgery, chemotherapy, and radiotherapy. Advantages of radiotherapy in targeting the tumor are well known. However, even limited exposures of healthy tissues are of great concern, particularly regarding the effects on the intestinal barrier and the immune system. The adopted setup allows to study the interplay between two cell populations in a condition more similar to the physiological one, when compared to normal cell cultures. For this purpose, we resort to different techniques and we used an in vitro co-culture model, based on Caco-2 cells differentiated as a monolayer and PBMC, sharing the same culture medium. This protocol has been developed to focus on both macroscopic effects, i.e. cell viability and Trans-Epithelial Electrical Resistance (TEER), and, through western blot, molecular alterations, i.e. the activation of inflammatory pathway in immune cells and the tight junction protein expression in Caco-2 cells. Initial evaluation of radiation effects on Caco-2 cell viability was assessed via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Trypan blue assays, while TEER was measured at fixed time intervals through an ohmmeter specifically designed for co-culture systems. In this way, the effects due to radiation, the presence of Peripheral Blood Mononuclear Cells (PBMC), and eventually their synergistic effect, can be demonstrated. Through these complementary techniques, we observed a high radio-resistance of Caco-2 within the range of 2 - 10 Gy of X-rays and an increased Caco-2 monolayer permeability when PBMCs were added. In particular, PBMC presence was found to be associated with the variation in the tight junction scaffold proteins expression.

A Co-culture Method to Investigate the Crosstalk Between X-ray Irradiated Caco-2 Cells and PBMC

The protocol adopted in this work aims at unraveling how X-rays perturb the functioning of the intestinal barrier, focusing on the interplay between colorectal tumor cells and the immune system. Colorectal carcinoma is among the most common type of cancer, typically treated by surgery, chemotherapy, and radiotherapy. Advantages of radiotherapy in targeting the tumor are well known. However, even limited exposures of healthy tissues are of great concern, particularly regarding the effects on the intestinal barrier and the immune system. The adopted setup allows to study the interplay between two cell populations in a condition more similar to the physiological one, when compared to normal cell cultures. For this purpose, we resort to different techniques and we used an in vitro co-culture model, based on Caco-2 cells differentiated as a monolayer and PBMC, sharing the same culture medium. This protocol has been developed to focus on both macroscopic effects, i.e. cell viability and Trans-Epithelial Electrical Resistance (TEER), and, through western blot, molecular alterations, i.e. the activation of inflammatory pathway in immune cells and the tight junction protein expression in Caco-2 cells. Initial evaluation of radiation effects on Caco-2 cell viability was assessed via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Trypan blue assays, while TEER was measured at fixed time intervals through an ohmmeter specifically designed for co-culture systems. In this way, the effects due to radiation, the presence of Peripheral Blood Mononuclear Cells (PBMC), and eventually their synergistic effect, can be demonstrated. Through these complementary techniques, we observed a high radio-resistance of Caco-2 within the range of 2 - 10 Gy of X-rays and an increased Caco-2 monolayer permeability when PBMCs were added. In particular, PBMC presence was found to be associated with the variation in the tight junction scaffold proteins expression.

Metallated porphyrin-doped conjugated polymer nanoparticles for efficient photodynamic therapy of brain and colorectal tumor cells.

Assess biocompatibility, uptake and photodynamic therapy (PDT) mechanism of metallated porphyrin doped conjugated polymer nanoparticles (CPNs) in human brain and colorectal tumor cells and macrophages. CPNs were developed employing 9,9-dioctylfluorene-alt-benzothiadiazole, an amphiphilic polymer (PS-PEG-COOH), and platinum octaethylporphyrin. T98G, SW480 and RAW 264.7 cell lines were exposed to CPNs to assess uptake and intracellular localization. Additionally, a PDT protocol using CPNs was employed for thein vitro killing of cancer and macrophage cell lines. CPNs were well incorporated into glioblastoma and macrophage cells with localization in lysosomes. SW480 cells were less efficient incorporating CPNs with localization in the plasma membrane. In all cell lines PDT treatment was efficient inducing oxidative stress that triggered apoptosis.

Prognostic impact of a novel gene expression profile classifier for the discrimination between metastatic and non-metastatic primary colorectal cancer tumors.

Despite significant advances have been achieved in the genetic characterization of sporadic colorectal cancer (sCRC), the precise genetic events leading to the development of distant metastasis remain poorly understood. Thus, accurate prediction of metastatic disease in newly-diagnosed sCRC patients remains a challenge. Here, we evaluated the specific genes and molecular pathways associated with the invasive potential of colorectal tumor cells, through the assessment of the gene expression profile (GEP) of coding and non-coding genes in metastatic (MTX) vs. non-metastatic (non-MTX) primary sCRC tumors followed for >5 years. Overall, MTX tumors showed up-regulation of genes associated with tumor progression and metastatic potential while non-MTX cases displayed GEP associated with higher cell proliferation, activation of DNA repair and anti-tumoral immune/inflammatory responses. Based on only 19 genes a specific GEP that classifies sCRC tumors into two MTX-like and non-MTX-like molecular subgroups was defined which shows an independent prognostic impact on patient overall survival, particularly when it is combined with the lymph node status at diagnosis. In summary, we show an association between the global GEP of primary sCRC cells and their metastatic potential and defined a GEP-based classifier that provides the basis for further prognostic stratification of sCRC patients who are at risk of distant metastases.

Multicolor lineage tracing reveals clonal architecture and dynamics in colon cancer

Colon cancers are composed of phenotypically heterogeneous tumor cell subpopulations with variable expression of putative stem cell and differentiation antigens. While in normal colonic mucosa, clonal repopulation occurs along differentiation gradients from crypt base toward crypt apex, the clonal architecture of colon cancer and the relevance of tumor cell subpopulations for clonal outgrowth are poorly understood. Using a multicolor lineage tracing approach in colon cancer xenografts that reflect primary colon cancer architecture, we here demonstrate that clonal outgrowth is mainly driven by tumor cells located at the leading tumor edge with clonal axis formation toward the tumor center. While our findings are compatible with lineage outgrowth in a cancer stem cell model, they suggest that in colorectal cancer tumor cell position may be more important for clonal outgrowth than tumor cell phenotype.