Metastatic Spread Of Colorectal Cancer Research Articles

Olfactomedin 4 associates with expression of differentiation markers but not with properties of cancer stemness, EMT nor metastatic spread in colorectal cancer.

Tumor stem cells play a pivotal role in carcinogenesis and metastatic spread in colorectal cancer (CRC). Olfactomedin 4 (OLFM4) is co-expressed with the established stem cell marker leucine-rich repeat-containing G protein-coupled receptor 5 at the bottom of intestinal crypts and has been suggested as a surrogate for cancer stemness and a biomarker in gastrointestinal tumors associated with prognosis. Therefore, it was the aim of the present study to clarify whether OLFM4 is involved in carcinogenesis and metastatic spread in CRC. We used a combined approach of functional assays using forced OLFM4 overexpression in human CRC cell lines, xenograft mice, and an immunohistochemical approach using patient tissues to investigate the impact of OLFM4 on stemness, canonical Wnt signaling, properties of metastasis and differentiation as well as prognosis. OLFM4 expression correlated weakly with tumor grade in one patient cohort (metastasis collection: p= 0.05; pooled analysis of metastasis collection and survival collection: p= 0.19) and paralleled the expression of differentiation markers (FABP2, MUC2, and CK20) (p= 0.002) but did not correlate with stemness-associated markers. Further analyses in CRC cells lines as well as xenograft mice including forced overexpression of OLFM4 revealed that OLFM4 neither altered the expression of markers of stemness nor epithelial-mesenchymal transition, nor did OLFM4 itself drive proliferation, migration, or colony formation, which are all prerequisites of carcinogenesis and tumor progression. In line with this, we found no significant correlation between OLFM4 expression, metastasis, and patient survival. In summary, expression of OLFM4 in human CRC seems to be characteristic of differentiation marker expression in CRC but is not a driver of carcinogenesis nor metastatic spread.

PBXIP1 – An indicator for poor outcome and metastatic spread in colorectal cancer

Tumor cell heterogeneity in colorectal cancers within the same genetic background is a well-described phenomenon. In this work, we investigate the role of hematopoietic pre-B-cell leukemia transcription factor (PBX)-interacting protein (HPIP/PBXIP1) in tumor cell subpopulations with differential Wingless-related integration site (WNT) activity as well as its potential associations with epithelial-mesenchymal transition (EMT) and clinical associations in colorectal cancer. We used in situ analyses to identify immunohistochemical expression of PBXIP1 in normal and colorectal cancer tissues and biostatistical approaches to determine its function and regulatory correlations. Clinical associations were analyzed in a case control collection of metastatic and non-metastatic colon cancers and gene expression data sets of colorectal cancers with recorded clinical follow-up data. PBXIP1 was expressed in single epithelial cells from tumor-free colon crypts as well as in tumor cells with high WNT activity. Colorectal cancer cells close to the invasive edge seemed to possess higher PBXIP1 levels indicative of associations with EMT, whereas stromal cells in the tumor microenvironment appeared mostly negative. PBXIP1 expression was associated with local metastasis to lymph nodes as well as distant metastasis to secondary organs in a case-control collection consisting of 91 cases with or without distant metastasis. Furthermore, high expression of PBXIP1 in The Cancer Genome Atlas (TCGA) data set was associated with worse overall survival in colon cancer. PBXIP1 might serve as a novel histological prognostic and regulatory indicator for EMT processes in colorectal cancer that seems to correlate with cancer cell subtypes of high baseline WNT activity.

Tailored Systemic Therapy for Colorectal Cancer Liver Metastases.

Liver metastases are the most common site of metastatic spread in colorectal cancer. Current treatment approaches involve effective systemic therapies in combination with surgical and/or interventional strategies. Multimodal strategies greatly improved clinical outcomes of patients with metastatic colorectal cancer over the last decades. Identification of predictive and prognostic biomarkers helped to comprehensively refine individual targeted treatment approaches and resulted in median overall survival rates of 30 months or longer. Current guidelines, thus, recommend treatment selection according to patients’ performance status, tumor localization and stage as well as the tumor’s molecular and genetic status. Here, we outline the latest developments in molecular decision-making for patients with upfront resectable, potentially or initially unresectable and non/never-resectable colorectal cancer liver metastases.

LIN28 promotes tumorigenesis in colorectal cancer but is not associated with metastatic spread

BackgroundTumor stem cells play a role in metastatic spread in colorectal cancer (CRC). The oncogene LIN28A/B, a prognostic marker in CRC, is involved in tumorigenesis and maintains stem cell function. Therefore, it was the aim of the present study to clarify whether LIN28A/B is involved in metastatic spread in CRC. MethodsExpression of LIN28A/B was analyzed in patients with colon adenocarcinoma in a matched case-control study comparing patients with corresponding liver metastases (n = 42) and patients without hepatic spread within five years (n = 42) by applying immunohistochemistry. Further, LIN28A/B expression was correlated with stem cell associated markers (SOX2, CD133). ResultsLIN28A and B expression significantly correlated with SOX2 expression (p = .02, and p = .04 respectively) but not with CD133 expression. This correlation between LIN28 A/B and SOX2 was not reflected in differences in hepatic spread. In this respect, there was no significant association between LIN28A/B expression and liver metastases. ConclusionLIN28A/B might be involved in tumor initiation and progression in CRC but is not associated with hepatic spread.

A Sampling of Highlights from the Literature: Article Recommendations from Our Deputy and Senior Editors.

Intermittent resting of CAR T cells by preventing tonic signaling prevents and reverses exhaustion (from PxHere)Persistent, antigen-independent signaling through chimeric antigen receptors (CAR)—tonic signaling—can lead to CAR T-cell exhaustion. Weber et al. show that the functional, transcriptional, and epigenetic hallmarks of exhaustion that occur in CAR T cells because of tonic signaling can be prevented and reversed by intermittent cessation of tonic signaling by either switching a drug-regulated CAR on and off or using the small molecule dasatinib to inhibit proximal CAR signaling. Intermittently rested CAR T cells improve tumor control and survival in xenograft models, highlighting the potential clinical applicability of the data.Weber EW, …, Mackall CL. Science 2021 Apr 2;372:eaba1786.Epigenetic immunoediting creates an immunosuppressive TME in GBM (from Nephron via Wikimedia Commons)Glioblastoma multiforme (GBM) is refractory to immunotherapy, but knowledge of the immunosuppressive mechanisms at play in the tumor microenvironment (TME) is limited. Using a new model of GBM in which GBM stem cells (GSC) are serially transplanted into immunocompetent mice, Gangoso et al. find that sustained immune attack causes transcriptional and epigenetic changes in the GSCs. This immunoediting creates a myeloid-rich, immunosuppressive TME. Human GSCs from mesenchymal GBMs have similar transcriptional and DNA methylation changes, suggesting that epigenetic immunoediting may contribute to immune evasion in this GBM subtype.Gangoso E, …, Pollard SM. Cell 2021 Apr 29;184:2454–70.e26.Macrophages can promote antitumor immunity and chemoresistance (from Librepath via Wikimedia Commons)The role of macrophages in the effects of chemotherapy is unclear. Liu et al. show that chemotherapy has dual effects: It enhances macrophage promotion of antitumor immunity and chemoresistance. Chemotherapy-induced type I IFN production in tumors initiates NF-κB and Jak–STAT1 signaling in macrophages, leading to chemoresistance and antitumor immunity, respectively. STAT1 signaling also induces expression of cytoplasmic long noncoding RNA IFN-responsive NF-κB activator (IRENA) in macrophages, and this triggers the NF-κB–mediated chemoresistance. Knocking out IRENA in macrophages improves responses to chemotherapy in a mouse breast cancer model. As IRENA expression in postchemotherapy macrophages is associated with poor patient survival, these data have translational relevance.Liu J, …, Song E. Nat Cancer 2021 Apr 12;2:457–73.EIS can lead to generation of different neoantigens (from Horia Varlan via Wikimedia Commons)Exitron splicing (EIS) is a process that generates cryptic introns in protein-coding regions, and its role in cancer development and progression is not well-known. Wang et al. find that this process takes place in multiple cancer types and can alter expression of cancer driver genes and tumor neoantigens. This has the potential to impact antitumor responses, including those associated with immunotherapy responses. The study provides another perspective in the discovery of targetable neoantigens and emphasizes that EIS events should be considered when analyzing cancer-associated mutations.Wang T-Y, …, Yang R. Mol Cell 2021 Apr 15. DOI: 10.1016/j.molcel.2021.03.028.TGFβ is a double-edged sword for immunity (from Søren Niedziella via Flickr)TGFβ can both promote and suppress antitumor responses. Pei et al. investigated TGFβ in the context of Th9-mediated antitumor responses. TGFβ induces downregulation of BFAR (bifunctional apoptosis regulator), which then results in dampened TGFβ signaling and impaired Th9-mediated antitumor responses due to BFAR's role in modulating ubiquitination of TGFβR1 and Th9 differentiation. The study identifies BFAR as a regulator of TGFβ signaling and Th9 antitumor responses and offers a potential marker that should be considered in Th9-based immunotherapy.Pei S, …, Xiao Y. J Exp Med 2021 Apr 29;218:e20202144.E. coli plays a role in metastatic spread of CRC (from Eric Erbe and Christopher Pooley via Wikimedia Commons)Mechanisms behind the formation of the premetastatic niche are not fully understood. Bertocchi et al. find that PV-1 (plasmalemma vesicle–associated protein), a marker of gut vascular barrier (GVB) damage, is a biomarker for recurrent colorectal cancer (CRC) and that patients with PV-1high primary CRC have more bacterial colonization in metastatic liver lesions, especially by Escherichia coli. E. coli upregulates virulence-related genes and induces upregulation of PV-1, leading to GVB disruption that then allows migration of bacteria, immune cells, and tumor cells out of the colon and into the liver (i.e., a premetastatic niche is created). The data highlight a role of the gut microbiome in CRC metastatic spread and offer insights into possible targets to prevent metastases.Bertocchi A, …, Rescigno M. Cancer Cell 2021 May 10;39:708–24.e11.

Comprehensive characterization of neurotransmitters and neuronal signaling (NT) pathway alterations in colorectal cancer (CRC).

3537 Background: Aberrant NT signaling has been shown to activate uncontrolled proliferation and dissemination in several gastrointestinal cancer types. Neurotransmitters have been shown to affect endothelial cells and immune cells in the tumor microenvironment to promote tumor progression. We previously showed that single nucleotide polymorphisms in the dopamine and GABA pathways are associated with outcome in patients with metastatic CRC receiving first-line treatment. Here we further evaluated the distribution and molecular context of NT pathway alterations in CRC. Methods: A total of 7,595 CRC tumors tested at Caris Life Sciences (Phoenix, AZ) with NextGen Sequencing on DNA (Next Seq, 592 genes or NovaSeq, WES) and RNA (NovaSeq, WTS) were analyzed. ssGSEA (single-sample gene set enrichment analysis) was used to calculate pathway enrichment scores (ES) of 7 NT gene sets (GABA, nicotinic, muscarinic, dopamine (DA), reelin, glial cell line-derived neurotrophic factor and neurotrophins). X2/Fisher-Exact was used for comparison and significance was determined as p-value adjusted for multiple comparison of ( q) < 0.05. Results: ES based on sample sites showed a substantial heterogeneity in NT enrichment. Notably, when compared to primary tumors, all 7 gene sets were significantly enriched in brain metastases (mets; ES ratio 1.14-1.55), while abdomen, liver, and peritoneal mets displayed significant decreases in most NT gene sets. DA was enriched in ovarian and lung mets (ES ratio: 1.18 and 1.09, respectively), the latter also showing increased neurotrophins ES (1.06) (all q < 0.05). When investigating primary tumors grouped according to overall ES by unsupervised clustering, right-sided and CMS4 CRCs were more prevalent in the high ES cluster compared to the low ES cluster (32 vs 29%, P = 0.02 and 46 vs 30%, P < 0.001, respectively). In addition, tumors in the high ES cluster showed lower prevalence of TMB-H (≥ 10mt/MB) (7 vs 10%), MSI-H (6 vs 10%) and PD-L1 (2 vs 6%), while higher CNA rates were noted in 9 genes (all q < 0.05). High ES tumors showed significant positive associations with microenvironment infiltration of B cells, T cells (NK, CD4+ and CD8+ T cells, but not Treg), M2 Macrophages, Myeloid Dendritic Cell, Neutrophils, and an inverse association with M1 Macrophages, regardless of MSI status ( q < 0.05). Conclusions: This is the first and most extensive molecular profiling study to investigate NT signaling pathway alterations in CRC. Our data show a distinct distribution of pathway enrichment according to metastatic site, distinct molecular features in high vs low ES clusters in primary tumors (including CMS subtypes, TMB, MSI and PD-L1 rates), and differential immune cell infiltration. These findings support the role of NT signaling in the metastatic spread of CRC and modulation of tumor immune microenvironment.

IgG Fc Binding Protein (FCGBP) is Down-Regulated in Metastatic Lesions and Predicts Survival in Metastatic Colorectal Cancer Patients

BackgroundThe liver is the most frequent site for metastatic spread in colorectal cancer (CRC) patients, and these patients have much poorer prognosis than those without metastasis. Previous studies have shown that IgG Fc binding protein (FCGBP) plays important roles in tumorigenesis, progression, and prognosis, but its role in CRC metastasis remains unclear.PurposeIn this study, we are aimed to explore the significance of FCGBP in liver metastatic CRC (LMCRC) patients.MethodsWe analyzed the expression of FCGBP RNA between CRC primary samples and liver metastatic samples in the Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA). Next, we assessed the expression of FCGBP protein in 135 paired primary CRC (PC) samples and LMCRC samples. Finally, we explored the relationship between the expression features and clinicopathological characteristics.ResultsThe expression data of FCGBP were obtained from the GEO and TCGA databases. FCGBP RNA expression was evaluated between primary lesions (PC) and liver metastatic lesions (LM). FCGBP RNA was down-regulated in PC and LM, and especially lower in LM (p<0.001). Next, the expression of FCGBP protein was evaluated by an immunohistochemistry array in 135 paired primary tumor tissues and metastatic tissues. We found that FCGBP protein was down-regulated in primary lesions and metastatic lesions, especially in metastatic lesions. According to the immunohistochemistry score (SI), each cohort was divided into FCGBP-positive (SI=4–12) and FCGBP-negative (SI=0–3) groups. In both groups, the levels of CEA (PC group, 3.880 vs 77.049, p<0.001; LM group, 3.890 vs 14.239, p=0.008) and CA19-9 (PC group, 8.610 vs 111.700, p<0.001; LM group, 7.660 vs 19.380, p=0.037) were lower than those in the FCGBP-negative group. FCGBP positivity in the LM cohort was an independent risk factor in both overall survival (HR 1.573, 95% Cl [1.017–2.433], p=0.042) and disease-free survival (HR 1.869, 95% Cl [1.256–2.781], p=0.002).ConclusionThis study found a relationship between FCGBP expression and clinical information of LMCRC patients, and found that FCGBP expression decreased with disease development. The expression of FCGBP in liver metastasis is associated with both the overall and progression-free survival. Our results show that FCGBP could be a promising prognostic factor for LMCRC.

Antiangiogenic Tyrosine Kinase Inhibitors in Metastatic Colorectal Cancer: Focusing on Regorafenib.

The progress of metastatic colorectal cancer (mCRC) depends essentially on two signaling pathways: the first mediated by vascular endothelial growth factor (VEGF) and the second by epidermal growth factor receptor (EGFR). In colorectal cancer (CRC), the balance between pro-angiogenic and anti-angiogenic factors is disturbed in favor of a pro-angiogenic outcome (angiogenic switch) early in the neoplastic progression of adenomas, thus, resulting in neovascularization and eventually in malignant tumor progression. Furthermore, angiogenesis plays an important role in tumor growth and the formation of metastases. Several angiogenic growth factors have been identified to be highly expressed during the progression and metastatic spread of CRC, but VEGFA is the predominant angiogenic cytokine and the most consistently expressed factor during the metastatic process. Agents targeting VEGF/VEGFR signaling have shown efficacy in the treatment of mCRC and are currently approved in this setting. In this review, we summarize the role of antiangiogenic tyrosine kinase inhibitors (TKIs) in the treatment of mCRC, focusing on regorafenib.

Biomarker alterations associated with distinct patterns of metastatic spread in colorectal cancer

Metastatic spread is the most important life-threatening feature of colorectal cancer and is supposed to be mainly driven by alterations in different carcinogenic pathways. The present study compared mutation and expression profiles of distinctive biomarkers in colorectal cancer patients with different clinical metastatic patterns. As for a case-control study, patients were matched according to T category, grading and primary tumour site. Overall, 246 patients with either exclusive lung metastasis (N = 82), exclusive liver metastasis (N = 82) or non-metastatic colorectal cancer (N = 82) were identified. Paraffin-embedded specimens were examined for mutations in the RAS and RAF genes and for the expression of β-catenin and CD133. Clinical endpoints were presence or absence of distant metastasis, formation of metastasis in lungs versus the liver and survival. MAPK pathway mutations in either the KRAS, NRAS or BRAF gene were associated with the development of lung metastasis (63.4%) compared to the control group (47.6%; p = 0.04). MAPK pathway alterations plus high β-catenin expression were associated with metastasis to the lungs but not to the liver (28.0% vs. 13.4%; p = 0.02). High CD133 expression correlated with the development of liver metastasis compared to the control group (30.5% vs. 14.6%; p = 0.02). This data indicates that different patterns of distant spread are associated with specific biomarker alterations and may represent different molecular subtypes of colorectal cancer. However, underlying mechanisms of metastasis formation in different anatomic sites remains unclear. Since knowledge of the anticipated site of distant spread would substantially impact clinical management, further research is needed to identify solid biomarkers for different metastatic patterns.

Snail-1, ALDH1, and claudin-1 tissue proteinexpression in patients with colorectal cancer:clinicopathological and prognostic implications

BackgroundThe occurrence of distant metastases in colorectal cancer (CRC) is the most important parameter in assessment of the prognosis of patients with CRC. Epithelial–mesenchymal transition (EMT) is the process that is incriminated in the occurrence of metastatic spread in CRC. Snail-1 is a zinc-

Preclinical Efficacy of [V4 Q5 ]dDAVP, a Second Generation Vasopressin Analog, on Metastatic Spread and Tumor-Associated Angiogenesis in Colorectal Cancer.

PurposeControl of metastatic spread of colorectal cancer (CRC) remains as a major therapeutic challenge. [V4 Q5 ]dDAVP is a vasopressin peptide analog with previously reported anticancer activity against carcinoma tumors. By acting as a selective agonist of arginine vasopressin type 2 membrane receptor (AVPR2) present in endothelial and tumor cells, [V4Q5]dDAVP is able to impair tumor aggressiveness and distant spread. Our aim was to evaluate the potential therapeutic benefits of [V4Q5]dDAVP on highly aggressive CRC disease using experimental models with translational relevance.Materials and MethodsMurine CT-26 and human Colo-205 AVPR2-expressing CRC cell lines were used to test the preclinical efficacy of [V4Q5]dDAVP, both in vitro and in vivo.ResultsIn syngeneic mice surgically implanted with CT-26 cells in the spleen, sustained intravenous treatment with [V4Q5]dDAVP (0.3 µg/kg) dramatically impaired metastatic progression to liver without overt signs of toxicity, and also reduced experimental lung colonization. The compound inhibited in vivo angiogenesis driven by Colo-205 cells in athymic mice, as well as in vitro endothelial cell migration and capillary tube formation. [V4Q5]dDAVP exerted AVPR2-dependent cytostatic activity in vitro (IC50 1.08 µM) and addition to 5-fluorouracil resulted in synergistic antiproliferative effects both in CT-26 and Colo-205 cells.ConclusionThe present preclinical study establishes for the first time the efficacy of [V4Q5]dDAVP on CRC. These encouraging results suggest that the novel second generation vasopressin analog could be used for the management of aggressive CRC as an adjuvant agent during surgery or to complement standard chemotherapy, limiting tumor angiogenesis and metastasis and thus protecting the patient from CRC recurrence.

Lymph Node Metastases in Colon Cancer Are Polyclonal.

Purpose: Recent studies have highlighted the existence of subclones in tumors. Lymph nodes are generally the first location of metastasis for most solid epithelial tumors, including colorectal cancer. We sought to understand the genetic origin of lymph node metastasis in colorectal cancer by evaluating the relationship between colorectal cancer subclones present in primary tumors and lymph nodes.Experimental Design: A total of 33 samples from seven colorectal cancers, including two or three spatially disparate regions from each primary tumor and one to four matched lymph nodes for each tumor, underwent next-generation whole-exome DNA sequencing, Affymetrix OncoScan SNP arrays, and targeted deep confirmatory sequencing. We performed mapping between SNPs and copy number events from the primary tumor and matched lymph node samples, allowing us to profile heterogeneity and the mutational origin of lymph node metastases. The computational method PyClone was used to define subclones within each tumor. The method Clonality Inference in Tumors Using Phylogeny (CITUP) was subsequently used to infer phylogenetic relationships among subclones.Results: We found that there was substantial heterogeneity in mutations and copy number changes among all samples from any given patient. For each patient, the primary tumor regions and matched lymph node metastases were each polyclonal, and the clonal populations differed from one lymph node to another. In some patients, the cancer cell populations in a given lymph node originated from multiple distinct regions of a tumor.Conclusions: Our data support a model of lymph node metastatic spread in colorectal cancer whereby metastases originate from multiple waves of seeding from the primary tumor over time. Clin Cancer Res; 24(9); 2214-24. ©2017 AACRSee related commentary by Gerlinger, p. 2032.

Impact of pigment epithelium-derived factor on colorectal cancer in vitro and in vivo.

Pigment epithelial derived factor (PEDF) is a secreted glycoprotein that is a non-inhibitory member of the serine protease inhibitor (serpin) family. PEDF exhibits multiple biological properties including neuroprotective, anti-angiogenic, and immune-modulating. Interestingly, PEDF exerts the inhibitory effects in cancers derived from certain tissues, including prostatic, ovarian, and pancreatic carcinomas. The current study aimed to elucidate its role in colorectal cancer development. PEDF expression in human colorectal cancer tissue was assessed using quantitative polymerase chain reaction (qPCR) and immunohistochemical staining (IHC). The effect of treatment with recombinant PEDF on cellular function was examined using in vitro functional assays. PEDF expression was downregulated in colorectal cancer cell tissue. Treatment with recombinant PEDF resulted in significant decreases in the rate of colorectal cancer cell migration and invasion and an increase in cellular adhesion in colorectal cancer cell lines examined. These results indicate that upregulation of PEDF expression may serve as a new strategy for further investigation of therapeutic relevance to the prevention of the metastatic spread of colorectal cancer.

Association of differential miRNA expression with hepatic vs. peritoneal metastatic spread in colorectal cancer

BackgroundThough peritoneal carcinomatosis reflects a late stage of colorectal cancer (CRC), only few patients present with synchronous or metachronous liver metastases alongside their peritoneal carcinomatosis. It is hypothesized that this phenomenon may be causally linked to molecular characteristics of the primary CRC. This study used miRNA profiling of primary CRC tissue either metastasized to the liver, to the peritoneum or not metastasized at all thus to identify miRNAs potentially associated with defining the site of metastatic spread in CRC.MethodsTissue of the primary tumor stemming from CRC patients diagnosed for either liver metastasis (LM; n = 10) or peritoneal carcinomatosis (PER; n = 10) was analyzed in this study. Advanced CRC cases without metastasis (M0; n = 3) were also included thus to select on those miRNAs most potentially associated with determining metastatic spread in general. miRNA profiling of 754 different miRNAs was performed in each group. MiRNAs being either differentially expressed comparing PER and LM or even triple differentially expressed (PER vs. LM vs. M0) were identified. Differentially expressed miRNAs were further validated by in silico and functional analysis.ResultsComparative analysis identified 41 miRNAs to be differentially expressed comparing primary tumors metastasized to the liver as opposed to those spread to the peritoneum. A set of 31 miRNAs was significantly induced in primary tumors that spread to the peritoneum (PER), while the remaining 10 miRNAs were found to be repressed. Out of these 41 miRNAs a number of 25 miRNAs was triple-differentially expressed (i.e. differentially expressed comparing LM vs. PER vs. M0). The latter underwent in silico analysis. Finally, we demonstrated that miR-31 down-regulated c-MET in DLD-1 colon cancer cells.ConclusionsThis study demonstrates that CRC primary tumors spread to the peritoneum vs. metastasized to the liver display significantly different miRNA profiles. Larger patient cohorts will be needed to validate whether determination of e.g. miR-31 may aid to predict the course of disease and whether this may help to create individualized follow up or treatment protocols. To determine whether certain miRNAs may be involved in regulating the metastatic potential of CRC, functional studies will be essential.

Natural small molecule bigelovin suppresses orthotopic colorectal tumor growth and inhibits colorectal cancer metastasis via IL6/STAT3 pathway

Bigelovin, a sesquiterpene lactone, has been demonstrated to induce apoptosis, inhibit inflammation and angiogenesis in vitro, but its potential anti-metastatic activity remains unclear. In the present study, two colon cancer mouse models, orthotopic tumor allografts and experimental metastatic models were utilized to investigate the progression and metastatic spread of colorectal cancer after bigelovin treatments. Results showed that bigelovin (intravenous injection; 0.3–3 mg/kg) significantly suppressed tumor growth and inhibited liver/lung metastasis with modulation of tumor microenvironment (e.g. increased populations of T lymphocytes and macrophages) in orthotopic colon tumor allograft-bearing mice. Furthermore, the inhibitory activities were also validated in the experimental human colon cancer metastatic mouse model. The underlying mechanisms involved in the anti-metastatic effects of bigelovin were then revealed in murine colon tumor cells colon 26-M01 and human colon cancer cells HCT116. Results showed that bigelovin induced cytotoxicity, inhibition of cell proliferation, motility and migration in both cell lines, which were through interfering IL6/STAT3 and cofilin pathways. Alternations of the key molecules including Rock, FAK, RhoA, Rac1/2/3 and N-cadherin, which were detected in bigelovin-treated cancer cells, were also observed in the tumor allografts of bigelovin-treated mice. These findings strongly indicated that bigelovin has potential to be developed as anti-tumor and anti-metastatic agent for colorectal cancer.

CXCR4 receptor blockage reduces the contribution of tumor and stromal cells to the metastatic growth in the liver.

The liver is a common site for the metastatic spread of primary malignancies including colorectal cancer, and liver metastasis is a main cause of death in cancer patients. This is due to the complexity of the interactions taking place in the liver between tumor and stromal cells. In fact, cancer‑associated fibroblasts (CAFs) have been shown to support tumor growth through the CXCL12/CXCR4 axis. However, along with cancer cells, myeloid‑derived suppressor cells (MDSCs), immature dendritic cells with immunosuppressive potential, also express CXCR4. It has recently been demonstrated that reducing CXCL12 availability in the tumor microenvironment decreases liver metastasis. Therefore, blocking CXCL12 chemokine receptor CXCR4 may be a successful approach to diminish the metastatic spread of colorectal cancer to the liver. However, the subjacent mechanisms by which this chemokine influences the tumor are not fully understood. Thus, in order to uncover the role of CXCR4 during tumor cell/liver fibroblast crosstalk driving liver metastasis, the CXCR4 antagonist AMD3100 was used for invitro studies and in an invivo approach using an orthotopic model of liver metastasis in immune competent mice through intrasplenic injection of grafted C26 cells. Invitro blockage of CXCR4 led to an impaired migratory potential of tumor and hepatic stellate cells (HSCs) and a reduced tumor response to CXCL12. Invivo administration of AMD3100 to tumor‑bearing mice resulted in attenuated metastatic development in the liver, which was accompanied by an impaired infiltration of αSMA‑expressing cells within the tumors. In addition, a reduced CD11+Ly6G+ cell count in the liver was directly correlated with a reduction in MDSC numbers in the blood of AMD3100‑treated mice compared to the vehicle‑treated mice. Therefore, disruption of the CXCR4/CXCL12 axis by CXCR4 antagonist AMD3100 blocked the contribution of both cancer and stromal cells to the metastatic cascade in the liver.

Abstract B047: A novel and efficient therapeutic strategy to target β1 integrin in metastatic cells from different cancer types

Abstract Purpose: We aim to develop new therapeutic strategies to control advanced metastatic disease in cancer. We hypothesized that targeting α2β1 integrin activation with cadherin RGD blocking monoclonal antibodies is an efficient procedure to reduce metastatic spread in multiple tumors. Experimental Procedures: Monoclonal antibodies (mAbs) were generated against a 9-mer peptide containing the RGD motif and flanking sequences of CDH17 (aka LI-cadherin). Antibodies were tested for inhibition of β1 integrin activation, cell adhesion, proliferation and invasion assays using cell lines from different cancer types (KM12SM (colorectal), PANC1 (pancreatic), BLM (melanoma,) and MDA-MB-468 (breast)) expressing CDH17 and VE-cadherin. The impact of the CDH RGD-specific mAbs on cell signaling was assessed by Western blot. Swiss nude mice were used to generate liver and lung metastasis with colorectal and melanoma cancer cell lines. Results: CDH RGD-specific mAbs were prepared and characterized. They recognized CDH17 and VE-cadherin positive cells by immunoprecipitation, flow cytometry, and confocal microscopy. CDH RGD mAbs blocked β1 integrin activation in metastatic cancer cell lines from different cancer types, causing a significant reduction in cell adhesion and proliferation. Signaling events related with FAK, JNK, ERK, Src, and AKT phosphorylation were blocked by the mAbs at different extent, according to the cancer type. Finally, CDH RGD mAbs caused a significant and persistent survival in nude mice developing lung and liver metastasis after intravenous or intrasplenic cell inoculation. Conclusions: CDH RGD mAbs constitute a promising therapy to control metastatic spread in colorectal cancer, melanoma, and probably other tumors expressing CDH17, VE-cadherin, or related RGD cadherins. Citation Format: Ignacio Casal, Ruben A. Bartolomé, Marta Jaén, Carmen Aizpurua, Eva Calviño, Juan I. Imbaud. A novel and efficient therapeutic strategy to target β1 integrin in metastatic cells from different cancer types [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B047.

Repeated Resections of Hepatic and Pulmonary Metastases from Colorectal Cancer Provide Long-Term Survival.

Liver and lungs are the two most frequent sites of metastatic spread of colorectal cancer (CRC). Complete resection of liver and/or lung metastases is the only chance of cure, and several studies have reported an improved survival after an aggressive treatment. Nevertheless, CRC liver metastases (CLM) have been recognized as a pejorative factor for patients undergoing pulmonary metastasectomy. We report our experience with patients successively operated on for CRC hepatic and pulmonary metastasis (CPM) and seek to identify prognostic factors. All consecutive patients who had resection of CPM and CLM between 2001 and 2014 were enrolled in the study. Clinicopathological and survival data were retrospectively analysed. Forty-six patients underwent resections of both CLM and CPM. Hepatic resection preceded pulmonary resection in most cases (91.3%). The median intervals between the resection of the primary tumour and the hepatic recurrence and between hepatic and pulmonary recurrences were 12months [0-72] and 21.5months [1-84], respectively. The mortality rate following CPM resection was 4.3%. After a median follow-up of 41.5months [0-126], 35 patients recurred of whom 14 (40%) and 11(31.4%) could benefit from repeated resection of recurrent CLM and CPM, respectively. The median and 5-year overall survivals (OS) were 53months and 49%, respectively. No prognostic factor was identified. An aggressive management of CLM and CPM, including repeated resections, may provide a long-term survival comparable to survival of patients with unique metastasectomy. The absence of prognostic factor may reflect the highly selected pattern of the eligible patients.

Suppression of IL-8 Release by Sweet Olive Ethanolic Extract and Compounds in WiDr Colon Adenocarcinoma Cells.

Oxidative stress can stimulate the secretion of pro-inflammatory cytokines. Interleukin-8 (IL-8) has been implicated in the pathogenesis of inflammatory bowel disease and the metastatic spread of colorectal cancer. The flowers of Osmanthus fragrans (sweet olive) are used to alleviate dysentery with blood in the bowel, as well as stomach ache and diarrhea. However, the evidence of their therapeutic effects on these symptoms remains unclear. In the present study, the protective effects of sweet olive flower ethanolic extract (OFE) against oxidative stress in WiDr cells was assessed by evaluating its 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. In addition, cellular IL-8 secretion was evaluated. Notably, high-performance liquid chromatography showed verbascoside to be the primary constituent in OFE; it exhibited a DPPH scavenging activity with an IC50 of 8.23 μg/mL. Moreover, OFE (1 to 100 μg/mL) showed a potent, dose-dependent inhibitory effect on H2 O2 -induced IL-8 secretion in WiDr cells. Nine compounds were isolated from OFE based on a protective effect-guided purification process. Of these compounds, 5 phenolic compounds-verbascoside, phillygenin, tyrosol, methyl 4-hydroxycinnamate, and eutigoside A-reduced IL-8 secretion at 10 μg/mL treatment concentrations. Further analysis showed that the anti-inflammatory effects of OFE likely occurred via nuclear factor-κB pathway inhibition, which attenuates IL-8 secretion in cells. Collectively, these data suggest that OFE could be developed as an agent that suppresses IL-8 secretion to treat chronic inflammatory diseases.

Soluble IL-33 receptor sST2 inhibits colorectal cancer malignant growth by modifying the tumour microenvironment.

Interleukin-33 (IL-33) was recently shown to be involved in the inflammatory tumour microenvironment and the progression of colorectal cancer (CRC). We report here that the expression level of sST2, a soluble form of the IL-33 receptor (ST2L), is inversely associated with the malignant growth of CRC. sST2 is downregulated in high-metastatic cells compared with low-metastatic human and mouse CRC cells. Knockdown of sST2 in low-metastatic cells enhances tumour growth, metastasis and tumour angiogenesis, whereas its overexpression in high-metastatic cells suppresses these processes. Circulating and intratumourally administered sST2-Fc fusion protein reduce tumour growth, metastatic spread and tumour angiogenesis in mice bearing high-metastatic CRC. Mechanistically, sST2 suppresses IL-33-induced angiogenesis, Th1- and Th2-responses, macrophage infiltration and macrophage M2a polarization. In conclusion, we show that sST2 negatively regulates tumour growth and the metastatic spread of CRC through modification of the tumour microenvironment. Thus, the IL-33/ST2L axis may be a potential therapeutic target in CRC.