Molecular targets and pathways involved in liver metastasis of colorectal cancer

MACC1 and Gasdermin-E (GSDME) regulate the resistance of colorectal cancer cells to irinotecan

Metastasis-associated in colon cancer 1 (MACC1) is an oncogene associated with the progression and metastasis of many solid cancer entities. High expression of MACC1 is found in colorectal cancer (CRC) tissues. So far, the role of MACC1 in CRC cell pyroptosis and resistance to irinotecan is unclear. The cleavage of Gasdermin-E (GSDME) is the main executors of activated pyroptosis. We found that GSDME enhanced CRC cell pyroptosis and reduced their resistance to irinotecan, while MACC1 inhibited the cleavage of GSDME and CRC cell pyroptosis, promoted CRC cell proliferation, and enhanced the resistance of CRC cells to irinotecan. Therefore, CRC cells with high MACC1 expression and low GSDME expression had higher resistance to irinotecan, while CRC cells with low MACC1 expression and high GSDME expression had lower resistance to irinotecan. Consistently, by analyzing CRC patients who received FOLFIRI (Fluorouracil + Irinotecan + Leucovorin) in combination with chemotherapy in the GEO database, we found that CRC patients with low MACC1 expression and high GSDME expression had higher survival rate. Our study suggests that the expression of MACC1 and GSDME can be used as detection markers to divide CRC patients into irinotecan resistant and sensitive groups, helping to determine the treatment strategy of patients.

Intracellular and extracellular factors of colorectal cancer liver metastasis: a pivotal perplex to be fully elucidated

Metastasis is the leading cause of death in colorectal cancer (CRC) patients, and the liver is the most common site of metastasis. Tumor cell metastasis can be thought of as an invasion-metastasis cascade and metastatic organotropism is thought to be a process that relies on the intrinsic properties of tumor cells and their interactions with molecules and cells in the microenvironment. Many studies have provided new insights into the molecular mechanism and contributing factors involved in CRC liver metastasis for a better understanding of the organ-specific metastasis process. The purpose of this review is to summarize the theories that explain CRC liver metastasis at multiple molecular dimensions (including genetic and non-genetic factors), as well as the main factors that cause CRC liver metastasis. Many findings suggest that metastasis may occur earlier than expected and with specific organ-anchoring property. The emergence of potential metastatic clones, the timing of dissemination, and the distinct routes of metastasis have been explained by genomic studies. The main force of CRC liver metastasis is also thought to be epigenetic alterations and dynamic phenotypic traits. Furthermore, we review key extrinsic factors that influence CRC cell metastasis and liver tropisms, such as pre-niches, tumor stromal cells, adhesion molecules, and immune/inflammatory responses in the tumor microenvironment. In addition, biomarkers associated with early diagnosis, prognosis, and recurrence of liver metastasis from CRC are summarized to enlighten potential clinical practice, including some markers that can be used as therapeutic targets to provide new perspectives for the treatment strategies of CRC liver metastasis.

Downregulation of TUSC3 promotes EMT and hepatocellular carcinoma progression through LIPC/AKT axis

Background

Hepatocellular carcinoma (HCC) is one of the most common and malignant tumors in the digestive tract. Tumor Suppressor Candidate 3 (TUSC3) is one subunit of the endoplasmic reticulum Oligosaccharyl transferase (OST) complex, which plays an important role in N-glycosylation during the protein folding process. However, the role of TUSC3 in the initiation and progression of HCC has not been mentioned yet. In the present study, we aim to investigate the effects of TUSC3 on the initiation and progression of HCC.

Methods

Immunohistochemical assay and qRT-PCR were used to detect the expression of TUSC3 and lipase C hepatic type (LIPC) in HCC tissue and cells. Loss-of-function and gain-of-function were applied to detect the function of TUSC3 and LIPC in vivo and in vitro. Immunofluorescence assay and co-immunoprecipitation were used to detect the relationship between TUSC3 and LPC. Western blot was applied to detect the expression of epithelial–mesenchymal transition (EMT) markers and the Akt signaling pathway.

Results

TUSC3 was aberrantly decreased in hepatocellular carcinoma tissues compared to the matched adjacent normal tissues, which resulted in bigger size of tumor (P = 0.001, Table 2), worse differentiation (P = 0.006, Table 2) and an advanced BCLC stage. Down-regulation of TUSC3 led to the enhanced proliferation and migration of hepatocellular carcinoma cells in vivo and vitro, whereas the opposite effect could be observed in the TUSC3-overexpression group. The analysis of TUSC3 microarray showed that LIPC, a glycoprotein primarily synthesized and secreted by hepatocytes, was a downstream target of TUSC3, and it negatively modulated the development of HCC. The morphological changes in HCC cells indicated that TUSC3 regulated the epithelial-mesenchymal transition (EMT). Mechanistically, TUSC3 inhibited EMT progression through the LIPC/AKT axis.

Conclusion

Down-regulation of TUSC3 promotes EMT progression by activating AKT signaling via targeting LIPC in HCC, which is probably the possible mechanism driving TUSC3-deficient hepatocellular carcinoma cells toward a malignant phenotype.

Combinatorial treatment with statins and niclosamide prevents CRC dissemination by unhinging the MACC1-β-catenin-S100A4 axis of metastasis

Colorectal cancer (CRC) is the second-most common malignant disease worldwide, and metastasis is the main culprit of CRC-related death. Metachronous metastases remain to be an unpredictable, unpreventable, and fatal complication, and tracing the molecular chain of events that lead to metastasis would provide mechanistically linked biomarkers for the maintenance of remission in CRC patients after curative treatment. We hypothesized, that Metastasis-associated in colorectal cancer-1 (MACC1) induces a secretory phenotype to enforce metastasis in a paracrine manner, and found, that the cell-free culture medium of MACC1-expressing CRC cells induces migration. Stable isotope labeling by amino acids in cell culture mass spectrometry (SILAC-MS) of the medium revealed, that S100A4 is significantly enriched in the MACC1-specific secretome. Remarkably, both biomarkers correlate in expression data of independent cohorts as well as within CRC tumor sections. Furthermore, combined elevated transcript levels of the metastasis genes MACC1 and S100A4 in primary tumors and in blood plasma robustly identifies CRC patients at high risk for poor metastasis-free (MFS) and overall survival (OS). Mechanistically, MACC1 strengthens the interaction of β-catenin with TCF4, thus inducing S100A4 synthesis transcriptionally, resulting in elevated secretion to enforce cell motility and metastasis. In cell motility assays, S100A4 was indispensable for MACC1-induced migration, as shown via knock-out and pharmacological inhibition of S100A4. The direct transcriptional and functional relationship of MACC1 and S100A4 was probed by combined targeting with repositioned drugs. In fact, the MACC1-β-catenin-S100A4 axis by statins (MACC1) and niclosamide (S100A4) synergized in inhibiting cancer cell motility in vitro and metastasis in vivo. The MACC1-β-catenin-S100A4 signaling axis is causal for CRC metastasis. Selectively repositioned drugs synergize in restricting MACC1/S100A4-driven metastasis with cross-entity potential.

Calcium-binding protein S100P is a new target gene of MACC1, drives colorectal cancer metastasis and serves as a prognostic biomarker

Background

The metastasis inducing gene MACC1 is a prognostic and predictive biomarker for metastasis in several cancers. Its mechanism of inducing metastasis includes the transcriptional control of other cancer-related target genes. Here, we investigate the interplay with the metastasis driver S100P in CRC progression.

Methods

MACC1-dependent S100P expression was analysed by qRT-PCR. The binding of MACC1 to the S100P promoter was determined by ChIP. Alterations in cell proliferation and motility were determined by functional in vitro assays. In vivo metastasis after intrasplenic transplantation was assessed by bioluminescence imaging and evaluation of tumour growth and liver metastasis. The prognostic value of S100P was determined in CRC patients by ROC-based Kaplan–Meier analyses.

Results

Expression of S100P and MACC1 correlated positively in CRC cells and colorectal tumours. MACC1 was found binding to the S100P promoter and induces its expression. The overexpression of S100P increased proliferation, migration and invasion in vitro and significantly induced liver metastasis in vivo. S100P expression was significantly elevated in metachronously metastasising CRC and was associated with shorter metastasis-free survival.

Conclusions

We identified S100P as a transcriptional target gene of MACC1. Expression of S100P increases the metastatic potential of CRC cells in vitro and in vivo, and serves as a prognostic biomarker for metastasis-free survival of CRC patients, emphasising novel therapeutic interventions targeting S100P.

Alpha-fetoprotein can promote gastric cancer progression via upregulation of metastasis-associated colon cancer 1

High serum alpha-fetoprotein (AFP) level is a predictor of poor prognosis in patients with gastric cancer (GC). AFP-producing GC (AFP-GC) is an aggressive subtype of GC characterized by a high incidence of liver metastasis and high c-Met expression. High expression of metastasis-associated colon cancer 1 (MACC1), which is the transcription activator of c-Met, also predicts a poor prognosis of GC. c-Met is known to be involved in tumor progression into malignant invasive phenotypes. Considering that high c-Met expression is simultaneously positively correlated with high AFP and MACC1 expression levels and that high expression of AFP or MACC1 predicts poor prognosis in GC, we hypothesized that an interaction may exist between AFP and MACC1. In the present study, GC cell lines with AFP-overexpression, MACC1-downregulation and the combination of both transfections were used as experimental models. The relative mRNA and protein expression of c-Met, AFP and MACC1 were analyzed using reverse transcription quantitative PCR and western blotting, respectively. Cell viability was evaluated using Cell Counting Kit-8 assay. Cell invasion and cell migration were examined using Transwell migration assay with and without Matrigel, respectively. The results demonstrated that, compared with the control group, the mRNA and protein expression of MACC1was significantly elevated in the AFP-overexpressed group and in the group with AFP overexpressed and MACC1 downregulated. Furthermore, a significantly enhanced cell viability, migration and invasion were observed in the AFP-overexpressing group, whereas opposite effects were found in the MACC1-downregulating group. In summary, the results from this study indicated that AFP may promote GC progression by stimulating MACC1. This finding may help illustrating the aggressive behaviors of GC in patients with high AFP serum level and AFP-GC.

miR‑483 promotes the development of colorectal cancer by inhibiting the expression level of EI24

MicroRNAs (miRs) serve an important role in cell differentiation, proliferation and apoptosis by negatively regulating gene expression at the transcriptional or post‑transcriptional level. EI24 autophagy associated transmembrane protein (EI24) is a tumor suppressor gene that serves an important role in the occurrence and development of digestive system tumors. However, little is known regarding the relationship between EI24 and the prognosis of patients with colorectal cancer (CRC). Our previous study confirmed EI24 as the target molecule of miR‑483, using reporter gene detection. Thus, the aim of the present study was to elucidate the effect of the abnormal expression of miR‑483 on the malignant phenotype of CRC through a series of cell function experiments and nude mice tumorigenicity experiments, and to determine the expression level of EI24, a downstream target gene of miR‑483, in CRC and its relationship with patient prognosis. In CRC tissues and cells, the expression level of miR‑483 was upregulated, while the expression level of EI24 was downregulated. Cell function tests such as MTT assay, cell cycle assay, colony formation assay, Migration and invasion assays and nude mice tumorigenicity experiments demonstrated that the overexpression of miR‑483 promoted the proliferation, invasion and metastasis of CRC. Moreover, the reverse transcription‑quantitative PCR results indicated that overexpression of miR‑483 inhibited the expression level of EI24. The relationship between the clinical data and immunohistochemical results from 183 patients with CRC and survival was examined. It was found that the expression level of EI24 was positively associated with the prognosis of patients. As a cancer‑promoting factor, miR‑483 enhances the proliferation, migration and invasion of CRC cells by reducing the expression level of EI24.

Emerging Mechanisms and Treatment Progress on Liver Metastasis of Colorectal Cancer

Colorectal cancer is currently the third largest malignant tumor in the world, with high new cases and high mortality. Metastasis is one of the most common causes of death of colorectal cancer, of which liver metastasis is the most fatal. Since the beginning of the Human Genome Project in 2001, people have gradually recognized the 3 billion base pairs that make up the human genome, of which only about 1.5% of the nucleic acid sequences are used for protein coding, including proto-oncogenes and tumor suppressor genes. A large number of differences in the expression of proto-oncogenes and tumor suppressor genes have also been found in the study of colorectal cancer, which proves that they are also actively involved in the progression of colorectal cancer and promote the occurrence of liver metastasis. Except for 1.5% of the coding sequence, the rest of the nucleic acid sequence does not encode any protein, which is called non-coding RNA. With the deepening of research, genome sequences without protein coding potential that were originally considered “junk sequences” may have important biological functions. Many years of studies have found that a large number of abnormal expression of ncRNA in colorectal cancer liver metastasis, indicating that ncRNA plays an important role in it. To explore the role and mechanism of these coding sequences and non-coding RNA in liver metastasis of colorectal cancer is very important for the early diagnosis and treatment of liver metastasis of colorectal cancer. This article reviews the coding genes and ncRNA that have been found in the study of liver metastasis of colorectal cancer in recent years, as well as the mechanisms that have been identified or are still under study, as well as the clinical treatment of liver metastasis of colorectal cancer.

microRNAs and Corresponding Targets Involved in Metastasis of Colorectal Cancer in Preclinical In Vivo Models

The high death toll of colorectal cancer patients is due to metastatic disease which is difficult to treat. The liver is the preferred site of metastasis, followed by the lungs and peritoneum. In order to identify new targets and new modalities of intervention we surveyed the literature for microRNAs (miRs) which modulate metastasis of colorectal cancer in preclinical in vivo models. We identified 12 up-regulated and 19 down-regulated miRs corresponding to the latter criterium. The vast majority (n=16) of identified miRs are involved in modulation of epithelial-mesenchymal transition (EMT). Other categories of metastasis-related miRs exhibit tumor- and metastasis-suppressing functions, modulation of signaling pathways, transmembrane receptors and a class of miRs, which interfere with targets which do not fit into these categories. Finally, we discuss the principles of miR inhibition and reconstitution of function, prospective clinical evaluation of with miR-related agents in the context of clinical evaluation in metastasis relevant settings.

Stathmin expression in metastatic colorectal cancer

OBJECTIVES

To evaluate the relationship between stathmin expression and clinical outcome in colorectal cancer (CRC).

BACKGROUND

Stathmin is a phosphoprotein involved in the regulation of microtubule dynamics and integration of intracellular signaling pathways. Stathmin has been implicated in the tumorigenesis of several cancers and is a potential therapeutic target.

METHODS

Stathmin expression was evaluated in 25 metastatic CRC (mCRC) patients by immunohistochemistry (IHC). Ki67 IHC and TUNEL assay were also evaluated in mCRC for cell proliferation and apoptosis.

RESULTS

High expression of stathmin was correlated with CRC metastasis (p = .0084), and significantly worse overall survival (OS) in CRC patients (p = .036). There was a significant increase in cell proliferation and a decrease in apoptosis in liver metastasis compared with CRC primary tumors as determined by Ki67 IHC and TUNEL assay (p < .0001). We also observed a significant positive correlation between stathmin level and cell proliferation in both CRC primary tumor and liver metastasis (p = .0429 to 0.0451; r = .4236 to .4288).

CONCLUSION

Stathmin expression correlated with worse patient prognosis in mCRC patients and positively correlated with increased cell proliferation. Together, our findings indicate stathmin as a novel potential marker for increased risk of CRC-specific mortality and identify stathmin as an attractive therapeutic target for the treatment of mCRC.

Myosin Motors: Novel Regulators and Therapeutic Targets in Colorectal Cancer

Simple Summary

Colorectal cancer (CRC) is a deadly disease that may go undiagnosed until it presents at an advanced metastatic stage for which few interventions are available. The development and metastatic spread of CRC is driven by remodeling of the actin cytoskeleton in cancer cells. Myosins represent a large family of actin motor proteins that play key roles in regulating actin cytoskeleton architecture and dynamics. Different myosins can move and cross-link actin filaments, attach them to the membrane organelles and translocate vesicles along the actin filaments. These diverse activities determine the key roles of myosins in regulating cell proliferation, differentiation and motility. Either mutations or the altered expression of different myosins have been well-documented in CRC; however, the roles of these actin motors in colon cancer development remain poorly understood. The present review aims at summarizing the evidence that implicate myosin motors in regulating CRC growth and metastasis and discusses the mechanisms underlying the oncogenic and tumor-suppressing activities of myosins.

Abstract

Colorectal cancer (CRC) remains the third most common cause of cancer and the second most common cause of cancer deaths worldwide. Clinicians are largely faced with advanced and metastatic disease for which few interventions are available. One poorly understood aspect of CRC involves altered organization of the actin cytoskeleton, especially at the metastatic stage of the disease. Myosin motors are crucial regulators of actin cytoskeletal architecture and remodeling. They act as mechanosensors of the tumor environments and control key cellular processes linked to oncogenesis, including cell division, extracellular matrix adhesion and tissue invasion. Different myosins play either oncogenic or tumor suppressor roles in breast, lung and prostate cancer; however, little is known about their functions in CRC. This review focuses on the functional roles of myosins in colon cancer development. We discuss the most studied class of myosins, class II (conventional) myosins, as well as several classes (I, V, VI, X and XVIII) of unconventional myosins that have been linked to CRC development. Altered expression and mutations of these motors in clinical tumor samples and their roles in CRC growth and metastasis are described. We also evaluate the potential of using small molecular modulators of myosin activity to develop novel anticancer therapies.

Surgery for Colorectal Cancer: A Trigger for Liver Metastases Development? New Insights into the Underlying Mechanisms

Surgery is a crucial intervention and provides the best chance of cure for patients with colorectal cancer. Experimental and clinical evidence, however, suggests that paradoxically surgery itself may precipitate or accelerate tumor recurrence and/or liver metastasis development. This review addresses the various aspects of surgery-induced metastasis formation and sheds light on the role of inflammation as potential trigger for metastasis development. Understanding these mechanisms may provide potential new perioperative interventions to improve treatment outcomes, and as such could transform the perioperative timeframe from a facilitator of metastatic progression to a window of opportunity to reduce the risk of liver metastasis development. Ultimately, this can potentially improve long-term survival rates and quality of life in patients with colorectal cancer.

Correlation of PRL3 expression with colorectal cancer progression

OBJECTIVES

To evaluate the relationship between phosphatase of regenerating liver 3 (PRL3) expression and clinical outcome in colorectal cancer (CRC).

BACKGROUND

PRL3, a protein tyrosine phosphatase functions as one of the key regulatory enzymes of various signal transduction pathways. PRL3 is highly expressed in a majority of cancers and is a novel potential therapeutic target.

METHODS

PRL3 expression was evaluated by immunohistochemistry in 167 patients with CRC, 37 patients with no disease, and 26 patients with metastatic CRC (mCRC). Phosphorylated Akt at serine 473 (p-Akt S473) expression was also evaluated by immunohistochemistry in mCRC patients.

RESULTS

High expression of PRL3 was correlated with CRC progression, and every one unit increase in PRL3 level contributed to an increase in the rate of death by 1%-1.7%. PRL3 expression was significantly higher in liver metastases compared with primary tumors and showed a significant positive correlation with the expression level of p-Akt S473.

CONCLUSION

PRL3 expression levels associated with CRC progression and metastasis, and positively correlated with activated Akt level in mCRC. Together, these findings indicated that PRL3 might be a potential marker for increased risk of CRC-specific tumor burden and identify PRL3 as an attractive therapeutic target for mCRC treatment.

Analysis of Key Genes Regulating the Warburg Effect in Patients with Gastrointestinal Cancers and Selective Inhibition of This Metabolic Pathway in Liver Cancer Cells

Objective

The Warburg effect, also known as aerobic glycolysis, plays a dominant role in the development of gastrointestinal (GI) cancers. In this study, we analyzed the expression of key genes involved in the Warburg effect in GI cancers and investigated the effect of suppressing the Warburg effect in vitro in liver cancer cell lines.

Methods

The Cancer Genome Atlas (TCGA) RNA-Seq data were used to determine gene expression levels, which were analyzed with GraphPad Prism 7.00. Genetic alterations were queried with cBioPortal. The influence of the Warburg effect on liver cancer cell viability, migration and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity was determined by means of MTT, transwell and GAPDH activity assays.

Results

The levels of expression of genes associated with the Warburg effect were increased in tumors. To our knowledge, this is the first report of upregulated expression of CUEDC2, HMGB2, PFKFB4, PFKP and SIX1 in liver cancer. Clinically, overexpression of these genes was associated with significantly worse overall survival of liver cancer patients. In vitro, selective inhibition of GADPH suppressed the growth and metastasis of Huh-7, Bel7404 and Hep3B hepatocellular carcinoma cell lines.

Conclusion

The Warburg effect may play an important role in GI cancers, especially in liver cancer.

Association between liver targeted antiviral therapy in colorectal cancer and survival benefits: An appraisal

In colorectal cancer (CRC), liver metastasis remains a major contributor to the cause of cancer-related death. Putative biomarkers, therapeutic efficacy, and drug insensitivity still pose clinical challenges for metastatic CRC patients. Interestingly, previous studies indicated that tumor cells in CRC did not metastasize to the injured liver, which included hepatitis or cirrhotic liver. The benefits of antiviral therapy on hepatocellular carcinoma have also been identified. This review discusses the role of antiviral therapy on the liver. Antiviral therapy may reduce potential liver metastasis associated with CRC in several mechanistic aspects.

Liver Tropism in Cancer: The Hepatic Metastatic Niche

The liver is the largest organ in the human body and is prone for cancer metastasis. Although the metastatic pattern can differ depending on the cancer type, the liver is the organ to which cancer cells most frequently metastasize for the majority of prevalent malignancies. The liver is unique in several aspects: the vascular structure is highly permeable and has unparalleled dual blood connectivity, and the hepatic tissue microenvironment presents a natural soil for the seeding of disseminated tumor cells. Although 70% of the liver is composed of the parenchymal hepatocytes, the remaining 30% is composed of nonparenchymal cells including Kupffer cells, liver sinusoidal endothelial cells, and hepatic stellate cells. Recent discoveries show that both the parenchymal and the nonparenchymal cells can modulate each step of the hepatic metastatic cascade, including the initial seeding and colonization as well as the decision to undergo dormancy versus outgrowth. Thus, a better understanding of the molecular mechanisms orchestrating the formation of a hospitable hepatic metastatic niche and the identification of the drivers supporting this process is critical for the development of better therapies to stop or at least decrease liver metastasis. The focus of this perspective is on the bidirectional interactions between the disseminated cancer cells and the unique hepatic metastatic niche.

Genome-Scale Metabolic Modeling with Protein Expressions of Normal and Cancerous Colorectal Tissues for Oncogene Inference

Although cancer has historically been regarded as a cell proliferation disorder, it has recently been considered a metabolic disease. The first discovery of metabolic alterations in cancer cells refers to Otto Warburg’s observations. Cancer metabolism results in alterations in metabolic fluxes that are evident in cancer cells compared with most normal tissue cells. This study applied protein expressions of normal and cancer cells to reconstruct two tissue-specific genome-scale metabolic models. Both models were employed in a tri-level optimization framework to infer oncogenes. Moreover, this study also introduced enzyme pseudo-coding numbers in the gene association expression to avoid performing posterior decision-making that is necessary for the reaction-based method. Colorectal cancer (CRC) was the topic of this case study, and 20 top-ranked oncogenes were determined. Notably, these dysregulated genes were involved in various metabolic subsystems and compartments. We found that the average similarity ratio for each dysregulation is higher than 98%, and the extent of similarity for flux changes is higher than 93%. On the basis of surveys of PubMed and GeneCards, these oncogenes were also investigated in various carcinomas and diseases. Most dysregulated genes connect to catalase that acts as a hub and connects protein signaling pathways, such as those involving TP53, mTOR, AKT1, MAPK1, EGFR, MYC, CDK8, and RAS family.

An Integrated Bioinformatics Analysis Repurposes an Antihelminthic Drug Niclosamide for Treating HMGA2-Overexpressing Human Colorectal Cancer

Aberrant overexpression of high mobility group AT-hook 2 (HMGA2) is frequently found in cancers and HMGA2 has been considered an anticancer therapeutic target. In this study, a pan-cancer genomics survey based on Cancer Cell Line Encyclopedia (CCLE) and The Cancer Genome Atlas (TCGA) data indicated that HMGA2 was mainly overexpressed in gastrointestinal cancers including colorectal cancer. Intriguingly, HMGA2 overexpression had no prognostic impacts on cancer patients’ overall and disease-free survivals. In addition, HMGA2-overexpressing colorectal cancer cell lines did not display higher susceptibility to a previously identified HMGA2 inhibitor (netroposin). By microarray profiling of HMGA2-driven gene signature and subsequent Connectivity Map (CMap) database mining, we identified that S100 calcium-binding protein A4 (S100A4) may be a druggable vulnerability for HMGA2-overexpressing colorectal cancer. A repurposing S100A4 inhibitor, niclosamide, was found to reverse the HMGA2-driven gene signature both in colorectal cancer cell lines and patients’ tissues. In vitro and in vivo experiments validated that HMGA2-overexpressing colorectal cancer cells were more sensitive to niclosamide. However, inhibition of S100A4 by siRNAs and other inhibitors was not sufficient to exert effects like niclosamide. Further RNA sequencing analysis identified that niclosamide inhibited more cell-cycle-related gene expression in HMGA2-overexpressing colorectal cancer cells, which may explain its selective anticancer effect. Together, our study repurposes an anthelminthic drug niclosamide for treating HMGA2-overexpression colorectal cancer.

Decoding and targeting the molecular basis of MACC1-driven metastatic spread: Lessons from big data mining and clinical-experimental approaches

Metastasis remains the key issue impacting cancer patient survival and failure or success of cancer therapies. Metastatic spread is a complex process including dissemination of single cells or collective cell migration, penetration of the blood or lymphatic vessels and seeding at a distant organ site. Hundreds of genes involved in metastasis have been identified in studies across numerous cancer types. Here, we analyzed how the metastasis-associated gene MACC1 cooperates with other genes in metastatic spread and how these coactions could be exploited by combination therapies: We performed (i) a MACC1 correlation analysis across 33 cancer types in the mRNA expression data of TCGA and (ii) a comprehensive literature search on reported MACC1 combinations and regulation mechanisms. The key genes MET, HGF and MMP7 reported together with MACC1 showed significant positive correlations with MACC1 in more than half of the cancer types included in the big data analysis. However, ten other genes also reported together with MACC1 in the literature showed significant positive correlations with MACC1 in only a minority of 5 to 15 cancer types. To uncover transcriptional regulation mechanisms that are activated simultaneously with MACC1, we isolated pan-cancer consensus lists of 1306 positively and 590 negatively MACC1-correlating genes from the TCGA data and analyzed each of these lists for sharing transcription factor binding motifs in the promotor region. In these lists, binding sites for the transcription factors TELF1, ETS2, ETV4, TEAD1, FOXO4, NFE2L1, ELK1, SP1 and NFE2L2 were significantly enriched, but none of them except SP1 was reported in combination with MACC1 in the literature. Thus, while some of the results of the big data analysis were in line with the reported experimental results, hypotheses on new genes involved in MACC1-driven metastasis formation could be generated and warrant experimental validation. Furthermore, the results of the big data analysis can help to prioritize cancer types for experimental studies and testing of combination therapies.

MACC1-the first decade of a key metastasis molecule from gene discovery to clinical translation

Deciphering the paths to metastasis and identifying key molecules driving this process is one important issue for understanding and treatment of cancer. Such a key driver molecule is Metastasis Associated in Colon Cancer 1 (MACC1). A decade long research on this evolutionarily conserved molecule with features of a transcription factor as well as an adapter protein for versatile protein-protein interactions has shown that it has manifold properties driving tumors to their metastatic stage. MACC1 transcriptionally regulates genes involved in epithelial-mesenchymal transition (EMT), including those which are able to directly induce metastasis like c-MET, impacts tumor cell migration and invasion, and induces metastasis in solid cancers. MACC1 has proven as a valuable biomarker for prognosis of metastasis formation linked to patient survival and gives promise to also act as a predictive marker for individualized therapies in a broad variety of cancers. This review discusses the many features of MACC1 in the context of the hallmarks of cancer and the potential of this molecule as biomarker and novel therapeutic target for restriction and prevention of metastasis.

Regeneration Enhances Metastasis: A Novel Role for Neurovascular Signaling in Promoting Melanoma Brain Metastasis

Neural repair after stroke involves initiation of a cellular proliferative program in the form of angiogenesis, neurogenesis, and molecular growth signals in the surrounding tissue elements. This cellular environment constitutes a niche in which regeneration of new blood vessels and new neurons leads to partial tissue repair after stroke. Cancer metastasis has similar proliferative cellular events in the brain and other organs. Do cancer and CNS tissue repair share similar cellular processes? In this study, we identify a novel role of the regenerative neurovascular niche induced by stroke in promoting brain melanoma metastasis through enhancing cellular interactions with surrounding niche components. Repair-mediated neurovascular signaling induces metastatic cells to express genes crucial to metastasis. Mimicking stroke-like conditions in vitro displays an enhancement of metastatic migration potential and allows for the determination of cell-specific signals produced by the regenerative neurovascular niche. Comparative analysis of both in vitro and in vivo expression profiles reveals a major contribution of endothelial cells in mediating melanoma metastasis. These results point to a previously undiscovered role of the regenerative neurovascular niche in shaping the tumor microenvironment and brain metastatic landscape.

Tn antigen promotes human colorectal cancer metastasis via H-Ras mediated epithelial-mesenchymal transition activation

Tn antigen is a truncated O-glycan, frequently detected in colorectal cancer (CRC), but its precise role in CRC metastasis is not well addressed. Here we investigated the effects of Core 1 β3Gal-T specific molecular chaperone (Cosmc) deletion-mediated Tn antigen exposure on CRC metastasis and its underlying mechanism. We first used CRISPR/Cas9 technology to knockout Cosmc, which is required for normal O-glycosylation, and thereby obtained Tn-positive CRC cells. We then investigated the biological consequences of Tn antigen expression in CRC. The results showed that Tn-positive cells exhibited an enhanced metastatic capability both in vitro and in vivo. A further analysis indicated that Tn antigen expression induced typical activation of epithelial-mesenchymal transition (EMT). Mechanistically, we found that H-Ras, which is known to drive EMT, was markedly up-regulated in Tn-positive cells, whereas knockdown of H-Ras suppressed Tn antigen induced activation of EMT. Furthermore, we confirmed that LS174T cells (Tn-positive) transfected with wild-type Cosmc, thus expressing no Tn antigen, had down-regulation of H-Ras expression and subsequent inhibition of EMT process. In addition, analysis of 438 samples in TCGA cohort demonstrated that Cosmc expression was reversely correlated with H-Ras, underscoring the significance of Tn antigen-H-Ras signalling in CRC patients. These data demonstrated that Cosmc deletion-mediated Tn antigen exposure promotes CRC metastasis, which is possibly mediated by H-Ras-induced EMT activation.

Development of novel predictive miRNA/target gene pathways for colorectal cancer distance metastasis to the liver using a bioinformatic approach

Background

Liver metastases are the major cause of colorectal cancer (CRC)-related deaths. However, there is no reliable clinical predictor for CRC progression to liver metastasis. In this study, we investigated possible predictors (miRNAs and biomarkers) for clinical application.

Methodology

The Gene Expression Omnibus (GEO) datasets GSE49355, GSE41258 and GSE81558 for genes and GSE54088 and GSE56350 for miRNAs were used to identify common differentially expressed genes (DEGs) and miRNAs between primary CRC tissues and liver metastases. The identified miRNAs and their targets from the DEGs were verified in datasets comprising gene, miRNA and miRNA exosome profiles of CRC patients with no distant metastases (M0) and distant metastases (M1); the interaction networks and pathways were also mapped.

Results

There were 49 upregulated and 13 downregulated DEGs and 16 downregulated and 14 upregulated miRNAs; between the DEGs and miRNA targets, there were five upregulated and four downregulated genes. MiR-20a was strongly correlated with the status of liver metastasis. MiR-20a, miR499a, and miR-576-5p were highly correlated with the metastatic outcomes. MiR-20a was significantly highly expressed in the M1 group. In an analysis of the miRNA target genes, we found that CDH2, KNG1, and MMP2 were correlated with CRC metastasis. We demonstrated a new possible pathway for CRC metastasis: miR-576-5p/F9, miR20a/MMP2, CTSK, MMP3, and miR449a/P2RY14. The regulation of IGF transport and uptake by IGFBPs, extracellular matrix organization, signal transduction and the immune system were the enriched pathways.

Conclusion

This model can predict CRC to liver metastases and the pathways involved, which can be clinically applicable.

Systematic Investigation of Scutellariae Barbatae Herba for Treating Hepatocellular Carcinoma Based on Network Pharmacology

As the fifth most common type of malignant cancers globally, hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide. As a long-time medicinal herb in Traditional Chinese Medicine (TCM), Scutellariae Barbatae Herba (SBH) has also been used for treating various cancers including HCC, but its underlying mechanisms have not been completely clarified. Presently, an innovative network-pharmacology platform was introduced to systematically elucidate the pharmacological mechanisms of SBH against HCC, adopting active ingredients prescreening, target fishing, and network analysis. The results revealed that SBH appeared to work on HCC probably through regulating 4 molecular functions, 20 biological processes, and hitting on 21 candidate targets involved in 40 pathways. By in-depth analysis of the first-ranked signaling pathway and hit genes, only TTR was highly and specially expressed in the liver tissue. TTR might play a crucial role in neutrophil degranulation pathway during SBH against HCC. Hence, TTR might become a therapeutic target of HCC. The study investigated the anti-hepatoma mechanisms of SBH from a holistic perspective, which provided a theoretical foundation for further experimental research and rational clinical application of SBH.

Analysis of potential genes and pathways associated with the colorectal normal mucosa-adenoma-carcinoma sequence

This study aimed to identify differentially expressed genes (DEGs) related to the colorectal normal mucosa-adenoma-carcinoma sequence using bioinformatics analysis. Raw data files were downloaded from Gene Expression Omnibus (GEO) and underwent quality assessment and preprocessing. DEGs were analyzed by the limma package in R software (R version 3.3.2). Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed with the DAVID online tool. In a comparison of colorectal adenoma (n = 20) and colorectal cancer (CRC) stage I (n = 31), II (n = 38), III (n = 45), and IV (n = 62) with normal colorectal mucosa (n = 19), we identified 336 common DEGs. Among them, seven DEGs were associated with patient prognosis. Five (HEPACAM2, ITLN1, LGALS2, MUC12, and NXPE1) of the seven genes presented a sequentially descending trend in expression with tumor progression. In contrast, TIMP1 showed a sequentially ascending trend. GCG was constantly downregulated compared with the gene expression level in normal mucosa. The significantly enriched GO terms included extracellular region, extracellular space, protein binding, and carbohydrate binding. The KEGG categories included HIF-1 signaling pathway, insulin secretion, and glucagon signaling pathway. We discovered seven DEGs in the normal colorectal mucosa-adenoma-carcinoma sequence that was associated with CRC patient prognosis. Monitoring changes in these gene expression levels may be a strategy to assess disease progression, evaluate treatment efficacy, and predict prognosis.

mRNA-miRNA bipartite network reconstruction to predict prognostic module biomarkers in colorectal cancer stage differentiation

Biomarker detection is one of the most important and challenging problems in cancer studies. Recently, non-coding RNA based biomarkers such as miRNA expression levels have been used for early diagnosis of many cancer types. In this study, a systems biology approach was used to detect novel miRNA based biomarkers for CRC diagnosis in early stages. The mRNA expression data from three CRC stages (Low-grade Intraepithelial Neoplasia (LIN), High-grade Intraepithelial Neoplasia (HIN) and Adenocarcinoma) were used to reconstruct co-expression networks. The networks were clustered to extract co-expression modules and detected low preserved modules among CRC stages. Then, the experimentally validated mRNA-miRNA interaction data were applied to reconstruct three mRNA-miRNA bipartite networks. Twenty miRNAs with the highest degree (hub miRNAs) were selected in each bipartite network to reconstruct three bipartite subnetworks for further analysis. The analysis of these hub miRNAs in the bipartite subnetworks revealed 30 distinct important miRNAs as prognostic markers in CRC stages. There are two novel CRC related miRNAs (hsa-miR-190a-3p and hsa-miR-1277-5p) in these 30 hub miRNAs that have not been previously reported in CRC. Furthermore, a drug-gene interaction network was reconstructed to detect potential candidate drugs for CRC treatment. Our analysis shows that the hub miRNAs in the mRNA-miRNA bipartite network are very essential in CRC progression and should be investigated precisely in future studies. In addition, there are many important target genes in the results that may be critical in CRC progression and can be analyzed as therapeutic targets in future research.

Organ-specific metastases obtained by culturing colorectal cancer cells on tissue-specific decellularized scaffolds

Metastatic disease remains the primary cause of mortality in cancer patients. Yet the number of available in vitro models to study metastasis is limited by challenges in the recapitulation of the metastatic microenvironment in vitro, and by difficulties in maintaining colonized-tissue specificity in the expansion and maintenance of metastatic cells. Here, we show that decellularized scaffolds that retain tissue-specific extracellular-matrix (ECM) components and bound signaling molecules enable, when seeded with colorectal cancer (CRC) cells, the spontaneous formation of three-dimensional cell colonies that histologically, molecularly and phenotypically resemble in vivo metastases. Lung and liver metastases obtained by culturing CRC cells on, respectively, liver and lung decellularized scaffolds retained their tissue-specific tropism when injected in mice. We also found that the engineered metastases contained signet ring cells, which has not previously been observed ex vivo. A culture system with tissue-specific decellularized scaffolds represents a simple and powerful approach for the study of organ-specific cancer metastases.

Asiatic acid inhibits proliferation, migration and induces apoptosis by regulating Pdcd4 via the PI3K/Akt/mTOR/p70S6K signaling pathway in human colon carcinoma cells

Previous studies have demonstrated that asiatic acid (AA), the major component of Centella asiatica, is able to meditate cytotoxic and anticancer effects on various types of carcinoma cells. In order to investigate the molecular mechanism that underlies the antitumor effect of AA, the present study investigated the effects of AA on proliferation, migration and apoptosis of SW480 and HCT116 colon cancer cells. Viability and changes in cell morphology in the cells were assessed by MTT assay and transmission electron microscopy, respectively. Colony formation analysis was used to observe proliferation of the single cell, and migratory ability of the cells was assessed by performing Transwell migration assay. Hoechst 33342 nuclear staining and flow cytometry were used to assess apoptosis in colon carcinoma cells. The expression of proteins associated with the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR)/p70S6K signaling pathway and epithelial-mesenchymal transition (EMT) marker were analyzed by western blotting. The present study revealed that proliferation and migration of colon carcinoma cells were inhibited by AA in a dose-dependent and time-dependent manner. Numerous apoptotic bodies were observed, and G₂/M and S phase progression were delayed in colon cancer cells treated with AA, but not in the control group. A number of phosphorylated proteins, including PI3K, Akt (Ser⁴⁷³), mTOR, ribosomal protein S6 kinase (p70S6K) downregulated, while the expression of Pdcd4 was upregulated following treatment with AA. Additionally, AA affects expression of EMT markers in a dose-dependent manner. On the basis of these results, it was concluded that AA inhibited proliferation, migration and induced apoptosis of colon cancer cells by regulating Pdcd4 via the PI3K/Akt/mTOR/p70S6K signaling pathway. These observations suggest that AA may be a potential therapeutic agent for the treatment of colon carcinoma.

The role of extracellular vesicles in mediating progression, metastasis and potential treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. As vectors for intercellular information exchange, the potential role of extracellular vesicles (EVs) in HCC formation, progression and therapy has been widely investigated. In this review, we explore the current status of the researches in this field. Altogether there is undeniable evidence that EVs play a crucial role in HCC development, metastasis. Moreover, EVs have shown great potential as drug delivery systems (DDSs) for the treatment of HCC. Exosomal miRNAs derived from HCC cells can enhance transformed cell growth in recipient cells by modulating the expression of transforming growth factor-β activated kinase-1(TAK1) and downstream signaling molecules. Furthermore, vacuolar protein sortin 4 homolog A(VPS4A) and insulin-like growth factor(IGF)-1 regulate exosome-mediated miRNAs transfer. Immune cells- derived EVs containing integrin αMβ2 or CD147 may facilitate HCC metastasis. In addition, EVs-mediated shuttle of long non-coding RNAs (lncRNAs), specifically linc- VLDLR and linc-ROR promote chemoresistance of malignant cells. Heat shock proteins (HSPs)-harboring exosomes derived from HCC tumor cells increase the antitumor effect of natural killer (NK) cells, thus enhancing HCC immunotherapy. Indeed, inhibition of HCC tumor growth has been associated with tumor cell-derived exosomes (TEX)-pulsed dentritic cells (DCs). Exosomes are also essential in liver metastasis during colorectal carcinoma (CRC) and pancreatic ductal adenocarcinomas (PDAC). Therefore, as nucleic acid and drug delivery vehicles, EVs show a tremendous potential for effective treatment against HCC.

CD44v6-competent tumor exosomes promote motility, invasion and cancer-initiating cell marker expression in pancreatic and colorectal cancer cells

Cancer-initiating cells (CIC) account for metastatic spread, which may rely mostly on CIC exosomes (TEX) that affect host cells and can transfer CIC features into Non-CIC. The CIC marker CD44 variant isoform v6 (CD44v6) being known for metastasis-promotion, we elaborated in cells its contribution to migration and invasion and in TEX the tranfer of migratory and invasive capacity to Non-CIC, using a CD44v6 knockdown (CD44v6kd) as Non-CIC model.A CD44v6kd in human pancreatic and colorectal cancer (PaCa, CoCa) lines led to loss of CIC characteristics including downregulation of additional CIC markers, particularly Tspan8. This aggravated the loss of CD44v6-promoted motility and invasion. Loss of motility relies on the distorted cooperation of CD44v6 and Tspan8 with associated integrins and loss of invasiveness on reduced protease expression. These deficits, transferred into TEX, severely altered the CD44v6kd-TEX composition. As a consequence, unlike the CIC-TEX, CD44v6kd TEX were not taken up by CD44v6kd cells and CIC. The uptake of CIC-TEX was accompanied by partial correction of CIC marker and protease expression in CD44v6kd cells, which regained migratory, invasive and metastatic competence. CIC-TEX also fostered angiogenesis and expansion of myeloid cells, likely due to a direct impact of CIC-TEX on the host, which could be supported by reprogrammed CD44v6kd cells.Taken together, the striking loss of tumor progression by a CD44v6kd relies on the capacity of CD44v6 to cooperate with associating integrins and proteases and its promotion of additional CIC marker expression. The defects by a CD44v6kd are efficiently corrected upon CIC-TEX uptake.

Annexin A9 promotes invasion and metastasis of colorectal cancer and predicts poor prognosis

Annexin A9 (ANXA9), a member of annexin family, has been reported be associated with colorectal cancer (CRC) carcinogenesis. However, the clinical significance of ANXA9 in CRC, particularly its correlation to invasion and metastasis remains ambiguous. The aim of the present study was to investigate the significance of ANXA9 in CRC and understand the molecular mechanism of ANXA9 in CRC invasion and metastasis. Expression levels of the ANXA9 protein in CRC tissues were detected using immunohistochemistry (IHC), and the clinical and prognostic value of ANXA9 was investigated. ANXA9‑siRNA was utilized to investigate the effect and molecular mechanism of ANXA9 in HCT116 cells. The IHC result demonstrated that the positivity rate of the ANXA9 protein in CRC tissue was significantly higher than that in adjacent mucosa (P<0.05), which was consistent with the western blot results. ANXA9 protein expression levels are associated with invasion depth and lymphatic metastasis. Furthermore, patients with ANXA9‑positive expression demonstrated a poor prognosis and ANXA9 was an independent risk factor for survival (P<0.05). After inhibiting ANXA9 in HCT116 cells, the activity and metastatic and invasion capacity of cells decreased significantly, and expression levels of ADAM metallopeptidase domain 17 and matrix metallopeptidase 9 were significantly downregulated, while the expression levels of tissue inhibitors of metalloproteinases‑1 and E‑cadherin were upregulated (P<0.05). Thus, positive ANXA9 expression may present as a novel marker for predicting poor prognosis in CRC patients, and ANXA9 may promote the invasion and metastasis of CRC by regulating invasion and metastasis‑associated genes.

Sciellin mediates mesenchymal-to-epithelial transition in colorectal cancer hepatic metastasis

Hepatic metastasis is the major cause of mortality in colorectal cancer (CRC) patients. Using proteomic analysis, we found sciellin (SCEL) to be specifically expressed in hepatic metastatic CRC cell lines. SCEL knockdown increased CRC cell migration and invasion, while overexpression had the opposite effect. SCEL knockdown also caused cancer cells to form more invasive structures within 3D cultures, increased the mesenchymal marker vimentin, and attenuated the epithelial marker E-cadherin. SCEL increased WNT signaling by activating β-catenin and its downstream target c-myc, and activated mesenchymal-to-epithelial transition (MET) through a SCEL-β-catenin-E-cadherin axis. SCEL showed higher expression in late stage primary CRC than in its hepatic metastatic counterpart. SCEL expression is dynamically modulated by TGF-β1 and hypoxia, revealing a plastic MET mechanism for tumor colonization. Intrahepatic injection in immunodeficient mice revealed that SCEL is necessary for metastatic CRC tumor growth in the liver. These results demonstrate that SCEL is a MET inducer dynamically regulated through the metastasis process. They suggest SCEL may be a useful therapeutic target for preventing or eliminating CRC hepatic metastasis.

Isolation of eudesmanes from Pluchea odorata and evaluation of their effects on cancer cell growth and tumor invasiveness in vitro

The traditionally used Central American medicinal plant Pluchea odorata, known as an anti-inflammatory and cancer cell growth-inhibiting remedy, was subjected to bioassay-guided isolation. Structure elucidation by 1D- and 2D-NMR and MS techniques supported by ECD and UV spectroscopic data revealed seven structurally previously undescribed and eight known eudesmane-type sesquiterpenes. Furthermore, one previously undescribed and one known phytol-like alcohol were identified. All compounds were tested for their cytotoxicity in cancer cells and for their anti-invasive effects. Among the eudesmanes, 3α-(2',3'-epoxy-2'-methylbutyryloxy)-4α-hydroxy-11-hydroperoxy-eudesm-6-en-8-one exhibited the most potent cytotoxic activity with an IC₅₀ value of 8.8 μM (after 48 h). Also in an in vitro model measuring the tumor-triggered breaching of the adjacent lymph endothelial cell barrier (3S*,4R*,5S*,10S*,2'R*,3'R*)-3-(2',3'-epoxy-2'-methylbutyryloxy)-4,7-dihydroxy-eudesm-11-en-8-one (IC₇₅ = 47 μM) and (3S*,4R*,5R*,10S*,2'R*,3'R*)-3-(2',3'-epoxy-2'-methylbutyryloxy)-4-acetyloxy-6-methoxy-11-hydroxy-eudesm-6-en-8-one (IC₇₅ = 73 μM) showed inhibitory activities. Furthermore, preliminary structure-activity relationships (SARs) of the eudesmanes were developed.

miR-133b suppresses metastasis by targeting HOXA9 in human colorectal cancer

Functions and mechanisms of microRNA (miRNA) involved in colorectal cancer (CRC) metastasis are largely unknown. Here, a miRNA microarray analysis was performed in CRC primary tissues and metastatic hepatic tissues to disclose crucial miRNA involved in CRC metastasis. MiR-133b was decreased and negatively correlated with metastasis in CRC. Overexpression of miR-133b significantly suppressed metastasis of CRC in vitro and in vivo. HOXA9 was identified as a direct and functional target of miR-133b. In addition, HOXA9 was negatively correlated with miR-133b and promoted CRC malignant progress. Moreover, miR-133b decreased HOXA9 expression, and subsequently downregulated ZEB1 and upregulated E-cadherin expression. Intriguingly, lower miR-133b and higher HOXA9 expression significantly contributed to poorer outcomes in CRC patients. Multivariate analysis indicated that miR-133b was an independent and significant predictor of CRC patient overall survival. In conclusion, we newly determined that miR-133b targeted the HOXA9/ZEB1 pathway to promote tumor metastasis in CRC cells. This axis provided insights into the mechanism underlying miRNA regulation of CRC metastasis and a novel therapeutic target for CRC treatment.

Vascular Invasion and Stromal S100A4 Expression at the Invasive Front of Colorectal Cancer are Novel Determinants and Tumor Prognostic Markers

Object: The aim of the present study was to investigate the clinicopathological characteristics and prognostic factors associated with sporadic colorectal cancer (CRC). We examined the clinicopathological findings and immunohistochemical expression of tumor prognostic markers at tumor budding sites to determine their predictive value for patient prognosis.

Materials and Methods: Immunohistochemical examination was performed by tissue microarray (TMA) of specimens from 106 patients with CRC. On hematoxylin and eosin (H&E)-stained tumor tissue slides, a representative area of tumor budding at the invasive front was selected for the construction of a TMA. Immunostaining for matrix metalloproteinase-7 (MMP7), the laminin-5 (ln-5) γ2 chain and S100A4 was performed to determine the association between patient survival and these markers.

Results: Clinicopathological variables were also assessed. Tumor location, histological type, degree of lymphatic invasion and vascular invasion, tumor stage, epithelial expression of S100A4, stromal cell expression of S100A4 and expression of the ln-5γ2 chain were associated with an increased risk of mortality. Five factors were retained in the multivariate logistic regression analysis. Specifically, the tumor location, degree of lymphatic invasion and vascular invasion, tumor stage and stromal cell expression of S100A4 remained significant predictors of patient survival after controlling for the other variables.

Conclusion: Vascular invasion and stromal expression of S100A4 in the tumor budding areas correlated with patient survival. Stromal immunostaining of S100A4 may be useful for identifying high-risk patients with advanced CRC.

MACC1 upregulation promotes gastric cancer tumor cell metastasis and predicts a poor prognosis

In various studies, metastasis associated with colon cancer 1 (MACC1) has been frequently reported to be abnormally highly expressed in human lung cancer, colon cancer, and hepatocellular carcinoma. Our study focuses on the association of MACC1 expression with gastric cancer (GC). During our experiment, the MACC1 expression was tested in 105 GC samples using an immunohistochemical (IHC) method. The clinical characteristics and prognosis of these patients were summarized. During analysis, MACC1 distribution in GC samples with distant metastasis was higher than that in normal samples and in tumors with no dissemination. Subsequently, a lower 5-year survival rate had a strong correlation with high MACC1 expression. As a consequence, the present results suggest that MACC1 is more frequently expressed in a poor prognosis phenotype of GC and acts as a promising prognostic prediction parameter for GC.

S100A4 in cancer progression and metastasis: A systematic review

Metastasis is the leading cause of cancer-related death and directly associates with cancer progression, resistance to anticancer therapy, and poor patient survival. Current efforts focusing on the underlying molecular mechanisms of cancer metastasis attract a special attention to cancer researchers. The epithelial-mesenchymal transition is a complex of molecular program during embryogenesis, inflammation, tissue fibrosis, and cancer progression and metastasis. S100A4, an important member of S100 family proteins, functions to increase the tumor progression and metastasis. The molecular mechanisms of S100A4 involving in the progression and metastasis are diverse in various malignant tumors. Detection of S100A4 expression becomes a promising candidate biomarker in cancer early diagnosis and prediction of cancer metastasis and therefore, S100A4 may be a therapeutic target. This review summarized up to date advancement on the role of S100A4 in human cancer development, progression, and metastasis and the underlying molecular events and then strategies to target S100A4 expression experimentally.

Peripheral blood leucocytes show differential expression of tumour progression-related genes in colorectal cancer patients who have a postoperative intra-abdominal infection: a prospective matched cohort study

AIM

Anastomotic leak is associated with higher rates of recurrence after surgery for colorectal cancer. However, the mechanisms responsible are unknown. We hypothesized that the infection-induced inflammatory response may induce overexpression of tumour progression-related genes in immune cells. The aim was to investigate the effect of postoperative intra-abdominal infection on the gene expression patterns of peripheral blood leucocytes (PBL) after surgery for colorectal cancer.

METHOD

Prospective matched cohort study. Patients undergoing surgery for colorectal cancer were included. Patients who had anastomotic leak or intra-abdominal abscess were included in the infection group (n = 23) and matched with patients without complications for the control group (n = 23). PBL were isolated from postoperative blood samples. Total RNA was extracted and hybridized to the Affymetrix Human Gene 1.0 ST microarray.

RESULTS

Patients in the infection group displayed 162 upregulated genes and 146 downregulated genes with respect to the control group. Upregulated genes included examples coding for secreted cytokines involved in tumour growth and invasion (S100P, HGF, MMP8, MMP9, PDGFC, IL1R2). Infection also upregulated some proangiogenic genes (CEP55, TRPS1) and downregulated some inhibitors of angiogenesis (MME, ALOX15, CXCL10). Finally, some inhibitors (HP, ORM1, OLFM4, IRAK3) and activators (GNLY, PRF1, FGFBP2) of antitumour immunity were upregulated and downregulated, respectively, suggesting that the inflammatory environment caused by a postoperative infection favours immune evasion mechanisms of the tumour.

CONCLUSION

Analysis of PBL shows differential expression of certain tumour progression-related genes in colorectal cancer patients who have a postoperative intra-abdominal infection, which in turn may promote the growth of residual cancer cells to become recurrent tumours.

Liver metastases: Microenvironments and ex-vivo models

The liver is a highly metastasis-permissive organ, tumor seeding of which usually portends mortality. Its unique and diverse architectural and cellular composition enable the liver to undertake numerous specialized functions, however, this distinctive biology, notably its hemodynamic features and unique microenvironment, renders the liver intrinsically hospitable to disseminated tumor cells. The particular focus for this perspective is the bidirectional interactions between the disseminated tumor cells and the unique resident cell populations of the liver; notably, parenchymal hepatocytes and non-parenchymal liver sinusoidal endothelial, Kupffer, and hepatic stellate cells. Understanding the early steps in the metastatic seeding, including the decision to undergo dormancy versus outgrowth, has been difficult to study in 2D culture systems and animals due to numerous limitations. In response, tissue-engineered biomimetic systems have emerged. At the cutting-edge of these developments are ex vivo 'microphysiological systems' (MPS) which are cellular constructs designed to faithfully recapitulate the structure and function of a human organ or organ regions on a milli- to micro-scale level and can be made all human to maintain species-specific interactions. Hepatic MPSs are particularly attractive for studying metastases as in addition to the liver being a main site of metastatic seeding, it is also the principal site of drug metabolism and therapy-limiting toxicities. Thus, using these hepatic MPSs will enable not only an enhanced understanding of the fundamental aspects of metastasis but also allow for therapeutic agents to be fully studied for efficacy while also monitoring pharmacologic aspects and predicting toxicities. The review discusses some of the hepatic MPS models currently available and although only one MPS has been validated to relevantly modeling metastasis, it is anticipated that the adaptation of the other hepatic models to include tumors will not be long in coming.

S100A4 in Cancer Metastasis: Wnt Signaling-Driven Interventions for Metastasis Restriction

The aberrant activity of Wnt signaling is an early step in the transformation of normal intestinal cells to malignant tissue, leading to more aggressive tumors, and eventually metastases. In colorectal cancer (CRC), metastasis accounts for about 90% of patient deaths, representing the most lethal event during the course of the disease and is directly linked to patient survival, critically limiting successful therapy. This review focuses on our studies of the metastasis-inducing gene S100A4, which we identified as transcriptional target of β-catenin. S100A4 increased migration and invasion in vitro and metastasis in mice. In patient CRC samples, high S100A4 levels predict metastasis and reduced patient survival. Our results link pathways important for tumor progression and metastasis: the Wnt signaling pathway and S100A4, which regulates motility and invasiveness. S100A4 suppression by interdicting Wnt signaling has potential for therapeutic intervention. As proof of principle, we applied S100A4 shRNA systemically and prevented metastasis in mice. Furthermore, we identified small molecule inhibitors from high-throughput screens of pharmacologically active compounds employing an S100A4 promoter-driven reporter. Best hits act, as least in part, via intervening in the Wnt pathway and restricted metastasis in mouse models. We currently translate our findings on restricting S100A4-driven metastasis into clinical practice. The repositioned FDA-approved drug niclosamide, targeting Wnt signaling, is being tested in a prospective phase II clinical trial for treatment of CRC patients. Our assay for circulating S100A4 transcripts in patient blood is used to monitor treatment success.

Genome-wide analysis of long noncoding RNA (lncRNA) expression in colorectal cancer tissues from patients with liver metastasis

The liver is the most frequent site of metastasis in colorectal cancer (CRC), in which long noncoding RNAs (lncRNAs) may play a crucial role. In this study, we performed a genome‐wide analysis of lncRNA expression to identify novel targets for the further study of liver metastasis in CRC. Samples obtained from CRC patients were analyzed using Arraystar human 8 × 60K lncRNA/mRNA v3.0 microarrays chips to find differentially expressed lncRNAs and mRNAs. The results were confirmed by quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR). The differentially expressed lncRNAs and mRNAs were identified through fold change filtering. Gene ontology (GO) and pathway analyses were performed using standard enrichment computational methods. In the CRC tissues from patients with liver metastasis, 2636 lncRNAs were differentially expressed, including 1600 up‐regulated and 1036 down‐regulated over two‐fold compared with the CRC tissues without metastasis. Among the 1584 differentially expressed mRNAs, 548 were up‐regulated and 1036 down‐regulated. GO and pathway analysis of the up‐regulated and down‐regulated mRNAs yielded different results. The up‐regulated mRNAs were associated with single‐organism process (biological process), membrane part (cellular component), and transporter activity (molecular function), whereas the down‐regulated mRNAs were associated with cellular process, membrane, and binding, respectively. In the pathway analysis, 27 gene pathways associated with the up‐regulated mRNAs and 51 gene pathways associated with the down‐regulated mRNAs were targeted. The significant changes in NQO2 (NM_000904) mRNA and six associated lncRNAs were selected for validation by qRT‐PCR. Aberrantly expressed lncRNAs may play an important role in the liver metastasis of CRC. The further study can provide useful insights into the biology and, ultimately, the prevention of liver metastasis.

Cortactin and Exo70 mediated invasion of hepatoma carcinoma cells by MMP-9 secretion

This study was aimed to evaluate the regulation mechanism of cortactin (CTTN) on matrix metalloproteinases 9 (MMP-9) and its relations with Exo70 in invasion of hepatoma carcinoma (HCC) cells. The expression levels of CTTN, Exo70 and MMP-9 were detected in normal hepatocytes and various HCC cells by real-time PCR. Then the migration and invasion ability of these cells was revealed by scratch and invasion assay. The effects of CTTN on MMP-9 and the ability of migration and invasion were evaluated by silence and overexpress CTTN. During this process, the expression of CTTN was detected by Western blot, the activity and concentration of MMP-9 in supernatant of culture medium was detected by zymography and ELISA assay. Besides, Exo70 was also inhibited to reveal its effects on MMP-9 and the migration and invasion ability of LM3. Increased expression of CTTN, MMP-9, Exo70, reduced scratch area and increased puncture cell numbers were found in HCC cells (p < 0.05). The expression of CTTN was significantly correlated with Exo70 and the migration and invasion ability of HCC (p < 0.05). In addition, the activity and concentration of MMP-9 were significantly affected by the expression level of CTTN, while the expression of MMP-9 was not influenced. Besides, Exo70-si also exhibited significantly inhibition effects on the activity and concentration of MMP-9 and puncture cell numbers (p < 0.05). A synergistic reaction may exhibited on CTTN and Exo70, which could mediate the secretion of MMPs thereby regulate tumor invasion.

ELL targets c-Myc for proteasomal degradation and suppresses tumour growth

Increasing evidence supports that ELL (eleven-nineteen lysine-rich leukaemia) is a key regulator of transcriptional elongation, but the physiological function of Ell in mammals remains elusive. Here we show that ELL functions as an E3 ubiquitin ligase and targets c-Myc for proteasomal degradation. In addition, we identify that UbcH8 serves as a ubiquitin-conjugating enzyme in this pathway. Cysteine 595 of ELL is an active site of the enzyme; its mutation to alanine (C595A) renders the protein unable to promote the ubiquitination and degradation of c-Myc. ELL-mediated c-Myc degradation inhibits c-Myc-dependent transcriptional activity and cell proliferation, and also suppresses c-Myc-dependent xenograft tumour growth. In contrast, the ELL(C595A) mutant not only loses the ability to inhibit cell proliferation and xenograft tumour growth, but also promotes tumour metastasis. Thus, our work reveals a previously unrecognized function for ELL as an E3 ubiquitin ligase for c-Myc and a potential tumour suppressor.