Integrative marker analysis allows risk assessment for metastasis in stage II colon cancer

KRAS inhibitors may prevent colorectal cancer metachronous metastasis by suppressing TGF‑β mediated epithelial‑mesenchymal transition

In colorectal cancer (CRC), KRAS mutations enhance metachronous metastasis, a condition without prognostic biomarkers or preventive measures. The present study demonstrated that KRAS mutation may be a risk factor for CRC metachronous metastasis through meta‑analysis of public databases. A risk scoring model was constructed using machine learning for predicting metachronous metastasis in KRAS‑mutant CRC. Wound healing and Transwell assay indicated that KRAS inhibitors strongly suppress migration and invasion capabilities of high‑risk CRC cells and these findings were validated through ex vivo organoid and a mouse model of splenic‑liver metastasis. Mechanistically, RNA sequencing, reverse transcription‑quantitative PCR and western blot analyses revealed that KRAS inhibitors suppressed epithelial‑mesenchymal transition (EMT) and transforming growth factor β (TGF‑β) signaling. Notably, addition of TGF‑β1 protein partially reversed the inhibitory effects of KRAS inhibitors on CRC. These results suggested that KRAS inhibitors may prevent CRC metachronous metastasis by downregulating TGF‑β‑mediated EMT, suggesting they can be used prophylactically in high‑risk KRAS‑mutant CRC.

Role of one-step nucleic acid amplification in colorectal cancer lymph node metastases detection

Current histopathological staging procedures in colorectal cancer (CRC) depend on midline division of the lymph nodes (LNs) with one section of hematoxylin and eosin staining. Cancer cells outside this transection line may be missed, which could lead to understaging of Union for International Cancer Control Stage II high-risk patients. The one-step nucleic acid amplification (OSNA) assay has emerged as a rapid molecular diagnostic tool for LN metastases detection. It is a molecular technique that can analyze the entire LN tissue using a reverse-transcriptase loop-mediated isothermal amplification reaction to detect tumor-specific cytokeratin 19 mRNA. Our findings suggest that the OSNA assay has a high diagnostic accuracy in detecting metastatic LNs in CRC and a high negative predictive value. OSNA is a standardized, observer-independent technique, which may lead to more accurate staging. It has been suggested that in stage II CRC, the upstaging can reach 25% and these patients can access postoperative adjuvant chemotherapy. Moreover, intraoperative OSNA sentinel node evaluation may allow early CRC to be treated with organ-preserving surgery, while in more advanced-stage disease, a tailored lymphadenectomy can be performed considering the presence of aberrant lymphatic drainage and skip metastases.

The Colorectal Cancer Lipidome: Identification of a Robust Tumor-Specific Lipid Species Signature

OBJECTIVE

Lipidomic changes were causally linked to metabolic diseases, but the scenario for colorectal cancer (CRC) is less clear. We investigated the CRC lipidome for putative tumor-specific alterations through analysis of 3 independent retrospective patient cohorts from 2 clinical centers, to derive a clinically useful signature.

DESIGN

Quantitative comprehensive lipidomic analysis was performed using direct infusion electrospray ionization coupled with tandem mass spectrometry (ESI-MS/MS) and high-resolution mass spectrometry (HR-MS) on matched nondiseased mucosa and tumor tissue in a discovery cohort (n = 106). Results were validated in 2 independent cohorts (n = 28, and n = 20), associated with genomic and clinical data, and lipidomic data from a genetic mouse tumor model (Apc1638N).

RESULTS

Significant differences were found between tumor and normal tissue for glycero-, glycerophospho-, and sphingolipids in the discovery cohort. Comparison to the validation collectives unveiled that glycerophospholipids showed high interpatient variation and were strongly affected by preanalytical conditions, whereas glycero- and sphingolipids appeared more robust. Signatures of sphingomyelin and triacylglycerol (TG) species significantly differentiated cancerous from nondiseased tissue in both validation studies. Moreover, lipogenic enzymes were significantly up-regulated in CRC, and FASN gene expression was prognostically detrimental. The TG profile was significantly associated with postoperative disease-free survival and lymphovascular invasion, and was essentially conserved in murine digestive cancer, but not associated with microsatellite status, KRAS or BRAF mutations, or T-cell infiltration.

CONCLUSION

Analysis of the CRC lipidome revealed a robust TG-species signature with prognostic potential. A better understanding of the cancer-associated glycerolipid and sphingolipid metabolism may lead to novel therapeutic strategies.

The newly identified MEK1 tyrosine phosphorylation target MACC1 is druggable by approved MEK1 inhibitors to restrict colorectal cancer metastasis

Cancer metastasis causes >90% of cancer deaths and remains a major treatment challenge. Here we deciphered the impact of tyrosine phosphorylation of MACC1, a causative driver for cancer metastasis, for cancer cell signaling and novel interventions to restrict cancer metastasis. We identified MACC1 as new MEK1 substrate. MEK1 directly phosphorylates MACC1, leading to accelerated and increased ERK1 activation. Mutating in silico predicted hierarchical MACC1 tyrosine phosphorylation sites abrogates MACC1-induced migration, invasion, and MET expression, a transcriptional MACC1 target. Targeting MEK1 by RNAi or clinically applicable MEK1 inhibitors AZD6244 and GSK1120212 reduces MACC1 tyrosine phosphorylation and restricts MACC1-induced metastasis formation in mice. Although MEK1 levels, contrary to MACC1, are not of prognostic relevance for CRC patients, MEK1 expression was found indispensable for MACC1-induced metastasis. This study identifies MACC1 as new MEK1 substrate for tyrosine phosphorylation decisively impacting cell motility, tumor growth, and metastasis. Thus, MAP kinase signaling is not linear leading to ERK activation, but branches at the level of MEK1. This fundamental finding opens new therapeutic options for targeting the MEK1/MACC1 axis as novel vulnerability in patients at high risk for metastasis. This might be extended from CRC to further solid tumor entities.

The emerging and diverse roles of the SLy/SASH1-protein family in health and disease-Overview of three multifunctional proteins

Intracellular adaptor proteins are indispensable for the transduction of receptor-derived signals, as they recruit and connect essential downstream effectors. The SLy/SASH1-adaptor family comprises three highly homologous proteins, all of them sharing conserved structural motifs. The initial characterization of the first member SLy1/SASH3 (SH3 protein expressed in lymphocytes 1) in 2001 was rapidly followed by identification of SLy2/HACS1 (hematopoietic adaptor containing SH3 and SAM domains 1) and SASH1/SLy3 (SAM and SH3 domain containing 1). Based on their pronounced sequence similarity, they were subsequently classified as one family of intracellular scaffold proteins. Despite their obvious homology, the three SLy/SASH1-members fundamentally differ with regard to their expression and function in intracellular signaling. On the contrary, growing evidence clearly demonstrates an important role of all three proteins in human health and disease. In this review, we systematically summarize what is known about the SLy/SASH1-adaptors in the field of molecular cell biology and immunology. To this end, we recapitulate current research about SLy1/SASH3, SLy2/HACS1, and SASH1/SLy3, with an emphasis on their similarities and differences.

IS THERE A CLINICAL PATHOLOGICAL CORRELATION OF COLORECTAL ADENOCARCINOMA WITH THE IMMUNOHISTOCHEMICAL EXPRESSION OF OPN AND ABCB5?

Background:

Studies with biomarkers in TMA (tissue microarray) have been showing important results regarding its expression in colon cancer.

Aim:

Correlate the expression profile of the OPN and ABCB5 biomarkers with the epidemiological and clinicopathological characteristics of the patients, the impact on the progression of the disease and the death.

Method:

A total of 122 CRC patients who underwent surgical resection, immunomarking and their relationship with progression and death events were evaluated.

Result:

The average age was 61.9 (±13.4) years. The cases were distributed in 42 (35.9%) in the ascending/transverse colon, 31 (26.5%) in the sigmoid, 27 in the rectum (23.1%), 17 (14.5%) in the descending colon. Most patients had advanced disease (stages III and IV) in 74 cases (60.9%). There was a predominance of moderately differentiated tumors in 101 samples (82.8%); despite this, the poorly differentiated subtype proved to be an independent risk factor for death in 70%. Metastasis to the liver proved to be an independent risk factor for death in 75% (18/24), as well as patients with primary rectal tumors in 81.5% (22/27).

Conclusion:

The immunohistochemical expression of the OPN and ABCB5 markers was not associated with epidemiological and clinicopathological characteristics. Regarding the progression of disease and death, it was not possible to observe a correspondence relationship with the evaluated markers.

Endoscopic ultrasound acquired portal venous circulating tumor cells predict progression free survival and overall survival in patients with pancreaticobiliary cancers

BACKGROUND AND AIMS

Despite recent advances, patients with pancreaticobiliary cancers have a poor prognosis. We previously demonstrated the efficacy of endoscopic ultrasound (EUS) guided acquisition of portal vein (PV) blood for enumeration of circulating tumor cells (CTCs). The aim of this study was to assess PV-CTCs as potential biomarkers for the assessment of progression-free (PFS) and overall survival (OS) in patients with pancreaticobiliary cancers.

METHODS

17 patients with biopsy-proven pancreaticobiliary malignancy were enrolled. CTCs were enumerated from both peripheral and PV blood. All patients were followed until death. PFS and OS were evaluated with the log-rank test and summarized with the use of Kaplan-Meier methods. Unadjusted and adjusted Cox-proportional hazards models were fitted to study the relationship between PV-CTCs and PFS and OS.

RESULTS

After 3.5 years of follow-up, all patients had expired. PV-CTCs were detected in all patients (median PV-CTCs 62.0/7.5 mL (interquartile range [IQR] 17-132). The mean PFS in patients with PV-CTCs <185/7.5 mL was significantly longer than patients with PV-CTCs ≥185/7.5 mL (43.3 weeks vs. 12.8 weeks, log-rank p = 0.002). The mean OS in patients with PV-CTCs <185/7.5 mL was significantly longer than patients with PV-CTCs ≥185/7.5 mL (75.8 weeks vs. 29.5 weeks, log-rank p = 0.021). In an adjusted Cox-proportional hazards model, PV-CTCs were significant predictors of both PFS and OS (HR 1.004, p = 0.037; HR 1.004, p = 0.044 respectively).

CONCLUSION

In this pilot and feasibility study, EUS-acquired PV-CTCs predicted PFS and OS. Our findings suggest that PV-CTCs can help provide important prognostic data for both providers and patients.

Five novel mutations in SASH1 contribute to lentiginous phenotypes in Japanese families

SASH1 has been reported as a causal gene of lentiginous phenotypes with and without heredity, including an autosomal dominant type characterized by lentigines predominantly on sun-exposed areas such as the face and limbs. Recently, cases of dyschromatosis with SASH1 mutations have been reported worldwide; however, only one case has been reported from Japan. Here, we analyzed six Japanese patients who characteristically showed many lentigines on sun-exposed areas, using next-generation sequencing. We identified five novel heterozygous mutations in SASH1 (p.I586M, p.S531Y, p.R644W, p.T525R, and p.S516I) in our patients and their families. The p.R644W substitution identified in two unrelated families was the first mutation located in the sterile alpha motif 1 (SAM1) domain. The degree and location of the lentigines were variable across individuals, even if they shared the same SASH1 mutation. All mutations were predicted to be deleterious by six different algorithms used to evaluate the functional impact of a variation. In addition, immunohistopathological findings and RNA sequencing results suggested that SASH1 mutations were associated with an increase in the number of melanocytes, acceleration of melanogenesis, and upregulated hair keratin expression.

Role of exosomes in malignant glioma: microRNAs and proteins in pathogenesis and diagnosis

Malignant gliomas are the most common and deadly type of central nervous system tumors. Despite some advances in treatment, the mean survival time remains only about 1.25 years. Even after surgery, radiotherapy and chemotherapy, gliomas still have a poor prognosis. Exosomes are the most common type of extracellular vesicles with a size range of 30 to 100 nm, and can act as carriers of proteins, RNAs, and other bioactive molecules. Exosomes play a key role in tumorigenesis and resistance to chemotherapy or radiation. Recent evidence has shown that exosomal microRNAs (miRNAs) can be detected in the extracellular microenvironment, and can also be transferred from cell to cell via exosome secretion and uptake. Therefore, many recent studies have focused on exosomal miRNAs as important cellular regulators in various physiological and pathological conditions. A variety of exosomal miRNAs have been implicated in the initiation and progression of gliomas, by activating and/or inhibiting different signaling pathways. Exosomal miRNAs could be used as therapeutic agents to modulate different biological processes in gliomas. Exosomal miRNAs derived from mesenchymal stem cells could also be used for glioma treatment. The present review summarizes the exosomal miRNAs that have been implicated in the pathogenesis, diagnosis and treatment of gliomas. Moreover, exosomal proteins could also be involved in glioma pathogenesis. Exosomal miRNAs and proteins could also serve as non-invasive biomarkers for prognosis and disease monitoring. Video Abstract.

Silencing SCAMP1-TV2 Inhibited the Malignant Biological Behaviors of Breast Cancer Cells by Interaction With PUM2 to Facilitate INSM1 mRNA Degradation

Background: Molecular-targeted therapy plays an important role in the combined treatment of breast cancer. Long noncoding RNA (LncRNA) plays a significant role in regulating breast cancer progression. The present study is to reveal the potential roles and molecular mechanism that the secretory carrier-associated membrane protein 1-transcript variant 2 (SCAMP1-TV2) has in breast.

Methods: Cell Counting Kit-8 (CCK-8), RNA Immunoprecipitation (RIP), and RNA pull-down assays were employed to determine the interactions between SCAMP1-TV2 and Pumilio RNA binding family member 2 (PUM2). The luciferase reporter assays and chromatin immunoprecipitation (ChIP) assays were used to get to know the effect of human insulinoma-associated 1 (INSM1) directly on the SAM and SH3 domain containing 1 (SASH1) promoter.

Results: Silenced SCAMP1-TV2 inhibited the proliferation, migration, and invasion of breast cancer cells, and promoted cell apoptosis. Meanwhile, SCAMP1-TV2 downregulation decreased its binding to PUM2 and increased the binding of PUM2 to INSM1 messenger RNA (mRNA), thus promoting the degradation of INSM1 mRNA. Silencing INSM1 decreased its inhibitory effect on SASH1 transcription and inhibited the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway. The xenograft tumor growth in a nude mice was significantly inhibited by the silencing of SCAMP1-TV2 in combination with the overexpression of PUM2.

Conclusions: SCAMP1-TV2/PUM2/INSM1 pathway plays an important role in regulating the biological behavior of breast cancer cells.

Novel role for CRK adaptor proteins as essential components of SRC/FAK signaling for epithelial-mesenchymal transition and colorectal cancer aggressiveness

Epithelial-mesenchymal transition (EMT) is a cell plasticity process required for metastasis and chemoresistance of carcinoma cells. We report a crucial role of the signal adaptor proteins CRK and CRKL in promoting EMT and tumor aggressiveness, as well as resistance against chemotherapy in colorectal and pancreatic carcinoma. Genetic loss of either CRKL or CRK partially counteracted EMT in three independent cancer cell lines. Strikingly, complete loss of the CRK family shifted cells strongly toward the epithelial phenotype. Cells exhibited greatly increased E-cadherin and grew as large, densely packed clusters, completely lacked invasiveness and the ability to undergo EMT induced by cytokines or genetic activation of SRC. Furthermore, CRK family-deficiency significantly reduced cell survival, proliferation and chemoresistance, as well as ERK1/2 phosphorylation and c-MYC protein levels. In accordance, MYC-target gene expression was identified as novel hallmark process positively regulated by CRK family proteins. Mechanistically, CRK proteins were identified as pivotal amplifiers of SRC/FAK signaling at focal adhesions, mediated through a novel positive feedback loop depending on RAP1. Expression of the CRK family and the EMT regulator ZEB1 was significantly correlated in samples from colorectal cancer patients, especially in invasive regions. Further, high expression of CRK family genes was significantly associated with reduced survival in locally advanced colorectal cancer, as well as in pan-cancer datasets from the TCGA project. Thus, CRK family adaptor proteins are promising therapeutic targets to counteract EMT, chemoresistance, metastasis formation and minimal residual disease. As proof of concept, CRK family-mediated oncogenic signaling was successfully inhibited by a peptide-based inhibitor.

Gene Expression Analysis of Human Papillomavirus-Associated Colorectal Carcinoma

PURPOSE

Human papillomavirus (HPV) antigens had been found in colorectal cancer (CRC) tissue, but little evidence demonstrates the association of HPV with oncogene mutations in CRC. We aim to elucidate the mutated genes that link HPV infection and CRC carcinogenesis.

METHODS

Cancerous and adjacent noncancerous tissues were obtained from CRC patients. HPV antigen was measured by using the immunohistochemical (IHC) technique. The differentially expressed genes (DEGs) in HPV-positive and HPV-negative tumor tissues were measured by using TaqMan Array Plates. The target genes were validated with the qPCR method.

RESULTS

15 (31.9%) cases of CRC patients were observed to be HPV positive, in which HPV antigen was expressed in most tumor tissues rather than in adjacent noncancerous tissues. With TaqMan Array Plates analyses, we found that 39 differentially expressed genes (DEGs) were upregulated, while 17 DEGs were downregulated in HPV-positive CRC tissues compared with HPV-negative tissues. Four DEGs (MMP-7, MYC, WNT-5A, and AXIN2) were upregulated in tumor vs. normal tissues, or adenoma vs. normal tissue in TCGA, which was overlapped with our data. In the confirmation test, MMP-7, MYC, WNT-5A, and AXIN2 were upregulated in cancerous tissue compared with adjacent noncancerous tissue. MYC, WNT-5A, and AXIN2 were shown to be upregulated in HPV-positive CRC tissues when compared to HPV-negative tissues.

CONCLUSION

HPV-encoding genome may integrate into the tumor genomes that involved in multiple signaling pathways. Further genomic and proteomic investigation is necessary for obtaining a more comprehensive knowledge of signaling pathways associated with the CRC carcinogenesis.

Prognostic value of Osteopontin (SPP1) in colorectal carcinoma requires a personalized molecular approach

Stratification of colorectal cancer for better management and tangible clinical outcomes is lacking in clinical practice. To reach this goal, the identification of reliable biomarker(s) is a prerequisite to deliver personalized colorectal cancer theranostics. Osteopontin (SPP1) is a key extracellular matrix protein involved in several pathophysiological processes including cancer progression and metastasis. However, the exact molecular mechanisms regulating its expression, localization, and molecular functions in cancer are still poorly understood. This study was designed to investigate the SPP1 expression profiles in Saudi colorectal cancer patients, and to assess its prognostic value. Hundred thirty-four (134) archival paraffin blocks of colorectal cancer were collected from King Abdulaziz University Hospital, Saudi Arabia. Tissue microarrays were constructed, and automated immunohistochemistry was performed to evaluate SPP1 protein expression patterns in colorectal cancer. About 20% and 23% of our colorectal cancer samples showed high SPP1 cytoplasmic and nuclear expression patterns, respectively. Cytoplasmic SPP1 did not correlate with age, gender, tumor size, and location. However, significant correlations were observed with tumor grade (p = 0.008), tumor invasion (p = 0.01), and distant metastasis (p = 0.04). Kaplan-Meier survival analysis showed a significantly lower recurrence rate in patients with higher SPP1 cytoplasmic expression (p = 0.05). At multivariate analysis, high SPP1 cytoplasmic expression was an independent favorable prognostic marker (p = 0.02). However, nuclear SPP1 expression did not show any prognostic value (p = 0.712). Our results showed a particular SPP1 prognostic relevance that is not in line with most colorectal cancer previous studies that may be attributed to the molecular pathophysiology of our colorectal cancer cohort. Saudi Arabia has both specific genomic makeup and particular environment that could lead to distinctive molecular roots of cancer. SPP1 has several isoforms, tissue localizations and molecular functions, signaling pathways, and downstream molecular functions. Therefore, a more individualized approach for CRC studies and particularly SPP1 prognosis outcomes' assessment is highly recommended toward precision oncology.

Two Isoforms of the Guanine Nucleotide Exchange Factor, Daple/CCDC88C Cooperate as Tumor Suppressors

Previously, Aznar et al., showed that Daple/CCDC88C enables Wnt receptors to transactivate trimeric G-proteins during non-canonical Wnt signaling via a novel G-protein binding and activating (GBA) motif. By doing so, Daple serves two opposing roles; earlier during oncogenesis it suppresses neoplastic transformation and tumor growth, but later it triggers epithelial-to-mesenchymal-transition (EMT). We have identified and characterized two isoforms of the human Daple gene. While both isoforms cooperatively suppress tumor growth via their GBA motif, only the full-length transcript triggers EMT and invasion. Both isoforms are suppressed during colon cancer progression, and their reduced expression carries additive prognostic significance. These findings provide insights into the opposing roles of Daple during cancer progression and define the G-protein regulatory GBA motif as one of the minimal modules essential for Daple’s role as a tumor suppressor.

High Frequency of KRAS Codon 146 and FBXW7 Mutations in Thai Patients with Stage II-III Colon Cancer

Background: KRAS, NRAS, and BRAF gene mutations are the most clinically relevant and frequently reported in colorectal cancer (CRC). Although data on these genes are frequently reported in several counties, data specific to these genes among Thai population are scarce. The aim of this study was to investigate and identify molecular alterations associated with colon cancer in Thai population, and to determine the impact of these genetic aberrations on clinical outcome. Methods: DNA from 108 archived formalin-fixed, paraffin-embedded (FFPE) tissue samples that histologically confirmed adenocarcinoma of stage II-III colon cancer between 2010 and 2012 at Siriraj Hospital (Bangkok, Thailand) were extracted. Gene mutational analysis was performed by next-generation sequencing (NGS) using an Oncomine Solid Tumor DNA kit (Thermo Fisher Scientific, Inc., Waltham, MA, USA). Results: A total of 22 somatic gene mutations were detected. The mutation frequency observed in KRAS, NRAS, BRAF, PIK3CA, and FBXW7 mutations was 47.2%, 1.9%, 1.9%, 12%, and 14.8%, respectively. KRAS mutation codon 12, 13, 59, 61, 117, and 146 mutations were identified in 29.6%, 8.3%, 1.8%, 0.9%, 0.0%, and 8.3%, respectively. KRAS Exon 4 had better DFS compared with Exon 2 and 3. Conclusions: This study is the first to comprehensively report hotspot mutations using NGS in Thai colon cancer patients. The most commonly identified gene mutation frequencies among Thai patients (KRAS, NRAS, BRAF, TP53, and PIK3CA) were similar to the gene mutation frequencies reported in Western population, except for subgroup of KRAS codon 146 and FBXW7 mutations that had a slightly higher frequency.

HMGB1 contributes to SASH1 methylation to attenuate astrocyte adhesion

SAM and SH3 domain-containing 1 (SASH1), a scaffold protein, is regarded as a tumor suppressor. Recent studies have verified the decreased expression of SASH1 in many tumors. Our previous clinical investigation found that SASH1 was widely expressed in normal brain tissues but reduced or absent in glioma tissues. However, the functions of SASH1 in normal astrocytes and the reasons for the reductions in SASH1 levels in glioma tissues are unclear. In this study, we found that in astrocytes, SASH1 functions in cell adhesion. We observed that knockdown of SASH1 expression in cultured astrocytes significantly decreased cell adhesion and increased invasion. Conversely, overexpression of SASH1 in C6 cells markedly promoted cell adhesion and decreased cell invasion. In addition, we found that the expression level of one member of the integrin family, integrin β8, was significantly reduced in SASH1-downregulated astrocytes and elevated in SASH1-upregulated C6 cells. Furthermore, the results of methylation and ChIP assays showed that the methylation level of the SASH1 gene was markedly higher in C6 cells than in astrocytes and that HMGB1 could bind to the CpG islands of the SASH1 gene. HMGB1 overexpression in astrocytes significantly increased the methylation level of the SASH1 gene. This study reveals, for the first time, that HMGB1 contributes to the methylation of the SASH1 gene, and our findings suggest that methylation downregulates the expression of the SASH1 gene and later reduces integrin β8 expression, thereby reducing cell adhesion and promoting cell migration.

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.

Clinical relevance of circulating MACC1 and S100A4 transcripts for ovarian cancer

Metastasis‐associated in colon cancer 1 (MACC1) and S100 calcium‐binding protein A4 (S100A4) are prominent inducers of tumor progression and metastasis. For the first time, we systematically tracked circulating serum levels of MACC1 and S100A4 transcripts in the course of surgery and chemotherapy and analyzed their clinical relevance for ovarian cancer. MACC1 and S100A4 transcripts were quantified in a total of 318 serum samples from 79 ovarian cancer patients by RT‐qPCR and digital droplet PCR, respectively. MACC1 and S100A4 transcripts were significantly elevated in serum of ovarian cancer patients, compared to healthy controls (P = 0.024; P < 0.001). At primary diagnosis, high levels of MACC1 or S100A4 correlated with advanced FIGO stage (P = 0.042; P = 0.008), predicted suboptimal debulking surgery and indicated shorter progression‐free survival (PFS; P = 0.003; P = 0.001) and overall survival (OS; P = 0.001; P = 0.002). This is the first study in ovarian cancer to propose circulating MACC1 and S100A4 transcripts as potential liquid biopsy markers.

Trends of incidence and survival in patients with gastrointestinal mucinous adenocarcinoma

The epidemiology and clinical outcome of gastrointestinal mucinous adenocarcinoma (MA) are not well illustrated. The present study aimed to explore the evolving epidemiology and prognostic factors that affect the survival of patients with MA in the gastrointestinal tract. A retrospective and population-based study was conducted to determine the annual age-adjusted incidence, overall survival (OS) and survival trend of gastrointestinal mucinous MA using nationally representative data from the Surveillance, Epidemiology, and End Results (SEER) program between 2000 and 2014. A Kaplan-Meier curve and a Cox proportional regression model were used to evaluate prognostic factors for this disease. Of the 51632 cases, females accounted for 50.5% (26058). The annual incidence of MA steadily decreased from 2000 to 2014. This trend occurred across all stages, grades and sites, apart from the appendix. In the SEER 18 registry grouping (2000-2014), the highest incidence was 3.333 per 100,000 persons for the colon. The median OS varied significantly between different primary sites, stages, grades, and age of clinical diagnosis, and the time period of diagnosis, according to a multivariable analysis. The five-year OS of gastrointestinal MA improved gradually between 2000 and 2014. The improvement in survival over the same interval was more pronounced in the subgroup of distant gastrointestinal MA. All sites along the alimentary tract, with the exception of the appendix, showed a decrease in the incidence of MA. Improved survival rates were observed for most of the gastrointestinal tract, especially for patients with advanced stage disease. MA in the upper gastrointestinal tract was less frequent but had poorer survival than colorectal MA. Clinicians should consider the primary tumour site when making therapeutic guidelines and treatment decisions for gastrointestinal MA.

Activated ATF6 Induces Intestinal Dysbiosis and Innate Immune Response to Promote Colorectal Tumorigenesis

BACKGROUND & AIMS

Activating transcription factor 6 (ATF6) regulates endoplasmic reticulum stress. We studied whether ATF6 contributes to the development of colorectal cancer (CRC) using tissue from patients and transgenic mice.

METHODS

We analyzed data from 541 patients with CRC in The Cancer Genome Atlas database for genetic variants and aberrant expression levels of unfolded protein response genes. Findings were validated in a cohort of 83 patients with CRC in Germany. We generated mice with intestinal epithelial cell-specific expression of the active form of Atf6 (nATF6IEC) from 2 alleles (homozygous), mice with expression of nATF6IEC from 1 allele (heterozygous), and nATF6IECfl/fl mice (controls). All nATF6IEC mice were housed under either specific-pathogen-free or germ-free conditions. Cecal microbiota from homozygous nATF6IEC mice or control mice was transferred into homozygous nATF6IEC mice or control mice. nATF6IEC mice were crossed with mice with disruptions in the myeloid differentiation primary response gene 88 and toll-like receptor adaptor molecule 1 gene (Myd88/Trif-knockout mice). Intestinal tissues were collected from mice and analyzed by histology, immunohistochemistry, immunoblots, gene expression profiling of unfolded protein response and inflammatory genes, array-based comparative genome hybridization, and 16S ribosomal RNA gene sequencing.

RESULTS

Increased expression of ATF6 was associated with reduced disease-free survival times of patients with CRC. Homozygous nATF6IEC mice developed spontaneous colon adenomas at 12 weeks of age. Compared with controls, homozygous nATF6IEC mice had changes in the profile of their cecal microbiota, increased proliferation of intestinal epithelial cells, and loss of the mucus barrier-all preceding tumor formation. These mice had increased penetration of bacteria into the inner mucus layer and activation of signal transducer and activator of transcription 3, yet inflammation was not observed at the pretumor or tumor stages. Administration of antibiotics to homozygous nATF6IEC mice greatly reduced tumor incidence, and germ-free housing completely prevented tumorigenesis. Analysis of nATF6IEC MyD88/TRIF-knockout mice showed that tumor initiation and growth required MyD88/TRIF-dependent activation of signal transducer and activator of transcription 3. Transplantation of cecal microbiota from nATF6IEC mice and control mice, collected before tumor formation, caused tumor formation in ex-germ-free nATF6IEC mice.

CONCLUSIONS

In patients with CRC, ATF6 was associated with reduced time of disease-free survival. In studies of nATF6IEC mice, we found sustained intestinal activation of ATF6 in the colon to promote dysbiosis and microbiota-dependent tumorigenesis.

Genetic and immunological biomarkers predict metastatic disease recurrence in stage III colon cancer

Background

Even though the post-operative outcome varies greatly among patients with nodal positive colon cancer (UICC stage III), personalized prediction of systemic disease recurrence is currently insufficient. We investigated in a retrospective setting whether genetic and immunological biomarkers can be applied for stratification of distant metastasis occurrence risk.

Methods

Eighty four patients with complete resection (R0) of stage III colon cancer from two clinical centres were analysed for genetic biomarkers: microsatellite instability, oncogenic mutations in KRAS exon2 and BRAF exon15, expression of osteopontin and the metastasis-associated genes SASH1 and MACC1. Tumor-infiltrating CD3 and CD8 positive T-cells were quantified by immunocytochemistry. Results were correlated with outcome and response to 5-FU based adjuvant chemotherapy, using Cox’s proportional hazard models and integrative two-step cluster analysis.

Results

Distant metastasis risk was significantly correlated with oncogenic KRAS mutations (p = 0.015), expression of SASH1 (p = 0.016), and the density of CD8-positive T-cells (p = 0.007) in Kaplan-Meier analysis. Upon multivariate Cox-regression analysis, KRAS mutation (p = 0.008) and density of CD8-positive TILs (p = 0.009) were retained as prognostic parameters for metachronous distant metastasis. Integrative two-step cluster analysis was used to combine all genetic markers, allowing stratification of patient subgroups. Post-operative distant metastasis risk ranged from 31% (low-risk) to 41% (intermediate), and 57% (high-risk) (p = 0.032). Increased expression of osteopontin (p = 0.019) and low density of CD8-positive T-cells (p = 0.043) were significantly associated with unfavourable response to 5-FU.

Conclusions

Integrative biomarker analysis allows stratification of stage III colon cancer patients for the risk of metastatic disease recurrence and may indicate response to 5-FU. Thus, biomarker analysis might facilitate the use of adjuvant therapy for high risk patients.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4940-2) contains supplementary material, which is available to authorized users.

The Tumor Suppressor SASH1 Interacts With the Signal Adaptor CRKL to Inhibit Epithelial-Mesenchymal Transition and Metastasis in Colorectal Cancer

BACKGROUND & AIMS

The tumor-suppressor sterile α motif- and Src-homology 3-domain containing 1 (SASH1) has clinical relevance in colorectal carcinoma and is associated specifically with metachronous metastasis. We sought to identify the molecular mechanisms linking decreased SASH1 expression with distant metastasis formation.

METHODS

SASH1-deficient, SASH1-depleted, or SASH1-overexpressing HCT116 colon cancer cells were generated by the Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated 9-method, RNA interference, and transient plasmid transfection, respectively. Epithelial-mesenchymal transition (EMT) was analyzed by quantitative reverse-transcription polymerase chain reaction, immunoblotting, immunofluorescence microscopy, migration/invasion assays, and 3-dimensional cell culture. Yeast 2-hybrid assays and co-immunoprecipitation/mass-spectrometry showed V-Crk avian sarcoma virus CT10 oncogene homolog-like (CRKL) as a novel interaction partner of SASH1, further confirmed by domain mapping, site-directed mutagenesis, co-immunoprecipitation, and dynamic mass redistribution assays. CRKL-deficient cells were generated in parental or SASH1-deficient cells. Metastatic capacity was analyzed with an orthotopic mouse model. Expression and significance of SASH1 and CRKL for survival and response to chemotherapy was assessed in patient samples from our department and The Cancer Genome Atlas data set.

RESULTS

SASH1 expression is down-regulated during cytokine-induced EMT in cell lines from colorectal, pancreatic, or hepatocellular cancer, mediated by the putative SASH1 promoter. Deficiency or knock-down of SASH1 induces EMT, leading to an aggressive, invasive phenotype with increased chemoresistance. SASH1 counteracts EMT through interaction with the oncoprotein CRKL, inhibiting CRKL-mediated activation of SRC kinase, which is crucially required for EMT. SASH1-deficient cells form significantly more metastases in vivo, depending entirely on CRKL. Patient tumor samples show significantly decreased SASH1 and increased CRKL expression, associated with significantly decreased overall survival. Patients with increased CRKL expression show significantly worse response to adjuvant chemotherapy.

CONCLUSIONS

We propose SASH1 as an inhibitor of CRKL-mediated SRC signaling, introducing a potentially druggable mechanism counteracting chemoresistance and metastasis formation.

Interferon-inducible CXC-chemokines are crucial immune modulators and survival predictors in colorectal cancer

Tumor-infiltrating T-cells are strongly associated with prognosis in colorectal cancer, but the mechanisms governing intratumoral lymphocyte recruitment are unclear. We investigated the clinical relevance and functional contribution of interferon-regulated CXC-chemokines CXCL9, CXCL10, and CXCL11, described as T-cells attractants. Their expression was significantly elevated in tumors as compared to normal colon in 163 patients with colon cancer, represented an independent positive predictor of post-operative survival, and was highly significantly correlated with the presence of tumor-infiltrating cytotoxic CD8⁺ T-cells and CD4⁺ T_H1-effector cells. The regulation of chemokine expression was investigated in established cell lines and in tissue explants from resected tumor specimen (n=22). All colorectal cancer cell lines tested, as well as stroma or endothelial cells, produced CXC-chemokines in response to cytokine stimulation. Moreover, resected tumor explants could be stimulated to produce CXC-chemokines, even in cases with initially low CXC-levels. Lastly, a causative role of chemokine expression was evaluated with an orthotopic mouse model, based on isogenic rectal CT26 cancer cells, engineered to express CXCL10. The orthotopic model demonstrated a protective and anti-metastatic role of intratumoral CXCL10 expression, mediated mainly by adaptive immunity.

Building personalized treatment plans for early-stage colorectal cancer patients

We developed a series of models to predict the likelihood of recurrence and the response to chemotherapy for the personalized treatment of stage I and II colorectal cancer patients. A recurrence prediction model was developed from 235 stage I/II patients. The model successfully distinguished between high-risk and low-risk groups, with a hazard ratio of recurrence of 4.66 (p < 0.0001). More importantly, the model was accurate for both stage I (hazard ratio = 5.87, p = 0.0006) and stage II (hazard ratio = 4.30, p < 0.0001) disease. This model performed much better than the Oncotype and ColoPrint commercial services in identifying patients at high risk for stage II recurrence. And unlike the commercial services, the robust model included recurrence prediction for stage I patients. As stage I/II CRC patients usually do not receive chemotherapy, we generated chemotherapy efficacy prediction models with data from 358 stage III patients. The predictions were highly accurate: the hazard ratio of recurrence for responders vs. non-responders was 4.13 for those treated with FOLFOX (p < 0.0001), and 3.16 (p = 0.0012) for those treated with fluorouracil. We have thus created a prognostic model that accurately identifies patients at high risk for recurrence, and the first accurate chemotherapy efficacy prediction model for individual patients. In the future, complete personalized treatment plans for stage I/II patients may be developed if the drug prediction models generated from stage III patients are verified to be effective for stage I and II patients in prospective studies.

Metastasis-associated in colon cancer 1: A promising biomarker for the metastasis and prognosis of colorectal cancer

Colorectal cancer (CRC) is the fourth most frequent type of malignancy in the world. Metastasis accounts for >90% mortalities in patients with CRC. The metastasis-associated in colon cancer 1 (MACC1) gene has been identified as a novel biomarker for the prediction of metastasis and disease prognosis, particularly for patients with early-stage disease. Previous clinical studies demonstrated that MACC1 expression and polymorphisms in CRC tissues were indicators of metastasis, and that circulating transcripts in plasma were also significantly associated with the survival of patients. The present review describes the use of MACC1 beyond its utility in the clinic. By elucidating the upstream and downstream signal pathways of MACC1, the well-known mechanisms of MACC1-mediated cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT) are summarized, as well as the potential signaling pathways. Furthermore, the underlying mechanisms by which the overexpression of MACC1 causes cisplatin resistance are emphasized.

Overexpression of MutL homolog 1 and MutS homolog 2 proteins have reversed prognostic implications for stage I-II colon cancer patients

BACKGROUND

The outcome of colon cancer patients without lymph node metastasis is heterogeneous. Searching for new prognostic markers is warranted.

METHODS

One hundred twenty stage I-II colon cancer patients who received complete surgical excision during 1995-2004 were selected for this biomarker study. Immunohistochemical method was used to assess p53, epidermal growth factor receptor, MLH1, and MSH2 status. KRAS mutation was examined by direct sequencing.

RESULTS

Thirty three patients (27.5%) developed metachronous metastasis during follow up. By multivariate analysis, only female gender (p = 0.03), high serum carcinoembryonic antigen (CEA) level (≧5 ng/ml) (p = 0.04), and MLH1 overexpression (p = 0.003) were associated with the metastasis group. The 5-year-survival rate were also significantly lower for female gender (71.7% versus 88.9%, p = 0.025), high CEA level (64.9% versus 92.4%, p < 0.001), and MLH1 overexpression (77.5% versus 94.4%, p = 0.039). In contrast, MSH2 overexpression was associated with better survival, 95.1% versus 75.5% (p = 0.024).

CONCLUSIONS

The reversed prognostic implications in the overexpression of MLH1 and MSH2 for stage I-II colon cancer patients is a novel finding and worthy of further confirmation.

SASH1 mediates sensitivity of breast cancer cells to chloropyramine and is associated with prognosis in breast cancer

Expression of the SASH1 protein is reduced in a range of human cancers and has been implicated in apoptotic cancer cell death. This study investigated whether increasing SASH1 expression could be a useful therapeutic strategy in breast cancer. Ectopic SASH1 expression increased apoptosis in 7/8 breast cancer cell lines. Subsequent in silico connectivity screening demonstrated that the clinically approved antihistamine drug, chloropyramine, increased SASH1 mRNA levels. Chloropyramine has previously been shown to have anti-tumour activity in breast cancer in part through modulation of FAK signalling, a pathway also regulated by SASH1. This study demonstrated that chloropyramine increased SASH1 protein levels in breast cancer cells. Consistent with this the agent reduced cell confluency in 7/8 cell lines treated irrespective of their ER status but not apoptosis incompetent MCF7 cells. In contrast SASH1 siRNA-transfected breast cancer cells exhibited reduced chloropyramine sensitivity. The prognostic significance of SASH1 expression was also investigated in two breast cancer cohorts. Expression was associated with favourable outcome in ER-positive cases, but only those of low histological grade/proliferative status. Conversely, we found a very strong inverse association in HER2+ disease irrespective of ER status, and in triple-negative, basal-like cases. Overall, the data suggest that SASH1 is prognostic in breast cancer and could have subtype-dependent effects on breast cancer progression. Pharmacologic induction of SASH1 by chloropyramine treatment of breast cancer warrants further preclinical and clinical investigation.

Clinicopathological and prognostic significance of metastasis-associated in colon cancer-1 (MACC1) overexpression in colorectal cancer: a meta-analysis

Metastasis-associated in colon cancer-1 (MACC1) has been reported to be overexpressed in diverse human malignancies, and the increasing amount of evidences suggest that its overexpression is associated with the development and progression of many human tumors. However, the prognostic and clinicopathological value of MACC1 in colorectal cancer remains inconclusive. Therefore, we conducted this meta-analysis to investigate the effect of MACC1 overexpression on clinicopathological features and survival outcomes in colorectal cancer. PubMed, CNKI, and Wanfang databases were searched for relevant articles published update to December 2015. Correlation of MACC1 expression level with overall survival (OS), disease-free survival (DFS), and clinicopathological features were analyzed. In this meta-analysis, fifteen studies with a total of 2,161 colorectal cancer patients were included. Our results showed that MACC1 overexpression was significantly associated with poorer OS and DFS. Moreover, MACC1 overexpression was significantly associated with gender, localization, TNM stage, T stage, and N stage. Together, our meta-analysis showed that MACC1 overexpression was significantly associated with poor survival rates, regional invasion and lymph-node metastasis. MACC1 expression level can serve as a novel prognostic factor in colorectal cancer patients.

The potential therapeutic applications and prognostic significance of metastasis-associated in colon cancer-1 (MACC1) in cancers

The metastasis-associated in colon cancer-1 (MACC1) gene was identified in 2009. Expression of MACC1 was found to be significantly upregulated in primary and metastatic colon carcinomas compared to normal tissues or adenomas. The induction of MACC1 occurs at the crucial step of transition from a benign to a malignant phenotype.

The aim of this review was to summarise current results of non-clinical and clinical studies on the role of MACC1 in the carcinogenesis and progression of cancer, as well its potential therapeutic and prognostic significance.

The gene encoding the HGF receptor MET is a transcriptional target of MACC1. In addition to promoting the proliferation, invasion, and migration of colon cancer cells in cell culture and tumour growth and metastasis in mouse models, MACC1 also contributes to carcinogenesis and progression of colorectal cancer through the β-catenin signalling pathway and mesenchymal-epithelial transition.

MACC1 knockdown with si/sh RNA was investigated in cell lines of different types of cancer. MACC1 is a promising therapeutic target for antitumour and antimetastatic intervention strategies for cancers. Here, it is presented as a potential independent prognostic indicator of reduced overall survival as well as of the occurrence of distant metastasis in patients with different types of cancer.

Increased MACC1 levels in tissues and blood identify colon adenoma patients at high risk

Background

Colorectal cancer is a preventable disease if caught at early stages. This disease is highly aggressive and has a higher incidence in African Americans. Several biomarkers and mutations of aggressive tumor behavior have been defined such as metastasis-associated in colon cancer 1 (MACC1) that was associated with metastasis in colorectal cancer patients. Here, we aim to assess colon tissue MACC1 protein and circulating MACC1 transcripts in colon preneoplastic and neoplastic African American patients.

Methods

Patients’ tissue samples (n = 143) have been arranged on three tissue microarrays for normal (n = 26), adenoma (n = 68) and cancer (n = 49) samples. Immunohistochemistry was used to detect MACC1 expression. Blood samples (n = 93) from normal (n = 45), hyperplastic (n = 15) and tubular adenoma (n = 33) patients were used to assess MACC1 transcripts using qRT-PCR. Distribution of continuous variables was tested between different diagnoses with Kruskal–Wallis test. Categorical variables were tested by Chi square test. We assessed the prognostic ability of IHC staining by calculating area under receiver operating characteristics curve (ROC) for adenoma and cancer separately. Differences between groups in terms of MACC1 transcript levels in plasma were calculated by using non-parametric (exact) Wilcoxon-Mann–Whitney tests. We performed all calculations with SPSS, version 21.

Results

In patient tissues, there was a statistically significant difference in MACC1 expression in normal vs. adenoma samples (p = 0.004) and normal vs. cancer samples (p < 0.001). There was however no major difference in MACC1 expression between adenoma vs. cancer cases or tubular adenomas vs tubulovillous adenomas. The area under the curve for both normal vs. adenoma and normal vs. cancer cases were 70 and 67 %, respectively. MACC1 expression was not correlated to age, gender or anatomical sample location. In patient plasma, MACC1 transcripts in adenoma patients were significantly higher than in plasma from normal patients (p = 0.014). However, the difference between normal and hyperplastic plasma MACC1 transcripts was not statistically significant.

Conclusion

Metastasis-associated in colon cancer 1 is expressed at early stages of colorectal oncogenesis within the affected colonic tissue in this patient cohort. The plasma transcripts can be used to stratify African American patients at risk for potential malignant colonic lesions.

IGFBP-3 Gene Methylation in Primary Tumor Predicts Recurrence of Stage II Colorectal Cancers

OBJECTIVES

To evaluate the influence of IGFBP-3 methylation on recurrence in patients with stage II colorectal cancer (CRC) from 2 independent cohorts.

BACKGROUND

The relationship between IGFBP-3 methylation in primary tumors (PTs) or lymph nodes (LNs) and risk of recurrence in patients with stage II CRC treated with surgery alone is unknown.

METHODS

IGFBP-3 methylation of DNA from 115 PTs and 1641 LNs in patients with stage II CRC from 2 independent cohorts was analyzed. Forty patients developed recurrence, whereas 75 matched patients remained recurrence free for more than 2 years after surgery. Cox proportional hazard models were used to calculate hazard ratios (HRs) of recurrence, adjusted for patient and tumor characteristics.

RESULTS

Methylation of IGFBP-3 in PTs was identified to be significantly associated with risk of recurrence in the training set. The signature was tested in a validation set and classified 40.7% of patients as high risk. Five-year recurrence-free survival rates were 76.4% and 58.3% for low- and high-risk patients, respectively, with an HR of 2.21 (95% confidence interval, 1.04-4.68; P = 0.039). In multivariate analysis, the signature remained the most significant prognostic factor, with an HR of 2.40 (95% confidence interval, 1.10-5.25; P = 0.029). A combined analysis of 1641 LNs from the 2 sets identified IGFBP-3 methylation in LNs was not associated with risk of recurrence.

CONCLUSIONS

Detection of IGFBP-3 methylation in PTs, but not in LNs, provides a powerful tool for the identification of patients with stage II CRC at high risk of recurrence.

SPON2, a newly identified target gene of MACC1, drives colorectal cancer metastasis in mice and is prognostic for colorectal cancer patient survival

MACC1 (metastasis associated in colon cancer 1) is a prognostic biomarker for tumor progression, metastasis and survival of a variety of solid cancers including colorectal cancer (CRC). Here we aimed to identify the MACC1-induced transcriptome and key players mediating the MACC1-induced effects in CRC. We performed microarray analyses using CRC cells ectopically overexpressing MACC1. We identified more than 1300 genes at least twofold differentially expressed, including the gene SPON2 (Spondin 2) as 90-fold upregulated transcriptional target of MACC1. MACC1-dependent SPON2 expression regulation was validated on mRNA and protein levels in MACC1 high (endogenously or ectopically) and low (endogenously or by knockdown) expressing cells. Chromatin immunoprecipitation analysis demonstrated the binding of MACC1 to the gene promoter of SPON2. In cell culture, ectopic SPON2 overexpression induced cell viability, migration, invasion and colony formation in endogenously MACC1 and SPON2 low expressing cells, whereas SPON2 knockdown reduced proliferative, migratory and invasive abilities in CRC cells with high endogenous MACC1 and SPON2 expression. In intrasplenically transplanted NOD/SCID mice, metastasis induction was analyzed with control or SPON2-overexpressing CRC cells. Tumors with SPON2 overexpression induced liver metastasis (vs control animals without any metastases, P=0.0036). In CRC patients, SPON2 expression was determined in primary tumors (stages I-III), and survival time was analyzed by Kaplan-Meier method. CRC patients with high SPON2 expressing primary tumors demonstrated 8 months shorter metastasis-free survival (MFS) compared with patients with low SPON2 levels (P=0.053). Combining high levels of SPON2 and MACC1 improved the identification of high-risk patients with a 20-month shorter MFS vs patients with low biomarker expression. In summary, SPON2 is a transcriptional target of the metastasis gene MACC1. SPON2 induces cell motility in vitro and CRC metastasis in mice. In patients, SPON2 serves as prognostic indicator for CRC metastasis and survival, and might represent a promising target for therapeutic approaches.

The E3 ligase RNF43 inhibits Wnt signaling downstream of mutated β-catenin by sequestering TCF4 to the nuclear membrane

Given its fundamental role in development and cancer, the Wnt-β-catenin signaling pathway is tightly controlled at multiple levels. RING finger protein 43 (RNF43) is an E3 ubiquitin ligase originally found in stem cells and proposed to inhibit Wnt signaling by interacting with the Wnt receptors of the Frizzled family. We detected endogenous RNF43 in the nucleus of human intestinal crypt and colon cancer cells. We found that RNF43 physically interacted with T cell factor 4 (TCF4) in cells and tethered TCF4 to the nuclear membrane, thus silencing TCF4 transcriptional activity even in the presence of constitutively active mutants of β-catenin. This inhibitory mechanism was disrupted by the expression of RNF43 bearing mutations found in human gastrointestinal tumors, and transactivation of the Wnt pathway was observed in various cells and in Xenopus embryos when the RING domain of RNF43 was mutated. Our findings indicate that RNF43 inhibits the Wnt pathway downstream of oncogenic mutations that activate the pathway. Mimicking or enhancing this inhibitory activity of RNF43 may be useful to treat cancers arising from aberrant activation of the Wnt pathway.

Influence of Smoking Status and Intensity on Discovery of Blood Pressure Loci Through Gene-Smoking Interactions

BACKGROUND

Genetic variation accounts for approximately 30% of blood pressure (BP) variability but most of that variability has not been attributed to specific variants. Interactions between genes and BP-associated factors may explain some "missing heritability." Cigarette smoking increases BP after short-term exposure and decreases BP with longer exposure. Gene-smoking interactions have discovered novel BP loci, but the contribution of smoking status and intensity to gene discovery is unknown.

METHODS

We analyzed gene-smoking intensity interactions for association with systolic BP (SBP) in three subgroups from the Framingham Heart Study: current smokers only (N = 1,057), current and former smokers ("ever smokers," N = 3,374), and all subjects (N = 6,710). We used three smoking intensity variables defined at cutoffs of 10, 15, and 20 cigarettes per day (CPD). We evaluated the 1 degree-of-freedom (df) interaction and 2df joint test using generalized estimating equations.

RESULTS

Analysis of current smokers using a CPD cutoff of 10 produced two loci associated with SBP. The rs9399633 minor allele was associated with increased SBP (5 mmHg) in heavy smokers (CPD > 10) but decreased SBP (7 mmHg) in light smokers (CPD ≤ 10). The rs11717948 minor allele was associated with decreased SBP (8 mmHg) in light smokers but decreased SBP (2 mmHg) in heavy smokers. Across all nine analyses, 19 additional loci reached P < 1 × 10(-6).

DISCUSSION

Analysis of current smokers may have the highest power to detect gene-smoking interactions, despite the reduced sample size. Associations of loci near SASH1 and KLHL6/KLHL24 with SBP may be modulated by tobacco smoking.

Metastasis-associated in colon cancer 1 is an independent prognostic biomarker for survival in Klatskin tumor patients

Curative treatment of intrahepatic cholangiocarcinoma (ICC) and hilar cholangiocarcinoma (Klatskin tumors) is limited to surgical resection or orthotopic liver transplantation. However, not all patients benefit from a surgical approach and suffer from early tumor recurrence. Response to chemotherapy is generally poor and, until today, no targeted therapy could be established. Metastasis-associated in colon cancer 1 (MACC1) is a recently discovered regulator of the hepatocyte growth factor (HGF)/Met/mitogen-activated protein kinase pathway, which induces proliferation, migration, and invasion in cell culture, as well as metastasis in mice. MACC1 expression shows a significant correlation with Met expression in colon cancer tissue and is highly prognostic for occurrence of distant metastasis and survival in colon cancer patients. Thus, we aimed to measure the expression of MACC1, Met, and HGF messenger RNA in microdissected tumor tissue and corresponding normal liver tissue of 156 patients with Klatskin tumors (n = 76) and ICC (n = 80) using real-time quantitative reverse-transcriptase polymerase chain reaction. We used immunohistochemical staining to validate the results. MACC1 expression in tumor tissue of both tumor entities was significantly higher than in corresponding normal liver tissue (P < 0.001). Klatskin tumor patients with a history of tumor recurrence had significantly higher MACC1 expression than those without tumor recurrence (P = 0.005). Uni- und multivariate survival analysis showed that Klatskin tumor patients with high MACC1 had a significantly shorter overall (OS) and disease-free survival (DFS; P = 0.001 and P < 0.001, respectively). The multivariate analysis confirmed MACC1 to be an independent factor for overall survival in Klatskin tumor patients (hazard ratio: 2.777; 95% confidence interval: 1.389-5.555; P = 0.004).

CONCLUSION

Our study identified MACC1 as a highly prognostic biomarker for OS and DFS in Klatskin tumor patients. MACC1 expression could become an important diagnostic tool and might be a candidate for targeted therapy.

SASH1, a new potential link between smoking and atherosclerosis

OBJECTIVE

We have previously reported that SASH1 expression is increased in circulating human monocytes from smokers and was positively correlated with the number of carotid atherosclerotic plaques. The aim of this study was to further validate the link between smoking, SASH1 and atherosclerosis within the vascular wall and to assess the impact of SASH1 expression on endothelial cell functions.

METHOD

Human carotids with atherosclerotic plaques were obtained from 58 patients (45 of them with known smoking status: smoker, non-smoker, ex-smokers), and were processed for gene expression analyses and immunostaining. To investigate its function, SASH1 was silenced in human aortic endothelial cells (HAECs) using two different siRNA and subcellular localization of SASH1 was determined by immunostaining and subcellular fractionation. Subsequently the transcriptomic analyses and functional experiments (wound healing, WST-1 proliferation or Matrigel assays) were performed to characterize SASH1 function.

RESULTS

SASH1 was expressed in human vascular cells (HAECs, smooth muscle cells) and in monocytes/macrophages. Its tissue expression was significantly higher in the atherosclerotic carotids of smokers compared to non-smokers (p < 0.01). In HAECs, SASH1 was expressed mostly in the cytoplasm and SASH1 knockdown resulted in an increased cell migration, proliferation and angiogenesis. Transcriptomic and pathway analyses showed that SASH1 silencing results in a decreased CYP1A1 expression possibly through the inhibition of TP53 activity.

CONCLUSION

We showed that SASH1 expression is increased in atherosclerotic carotids in smokers and its silencing affects endothelial angiogenic functions; therefore we provide a potential link between smoking and atherosclerosis through SASH1 expression.

The impact of osteopontin on prognosis and clinicopathology of colorectal cancer patients: a systematic meta-analysis

Colorectal cancer (CRC) is one of the most frequent malignant neoplasms worldwide. Up to now, no biomarker has been used to predict the prognosis and surveillance of patients with CRC. Recently, the association between osteopontin (OPN) overexpression and the prognosis of CRC was investigated widely, but the results were inconsistent. Therefore, the aim of present meta-analysis was to assess the prognostic effect of osteopontin in patients with CRC. PubMed, EMBASE, Web of Science, Scopus and Chinese Medical Database were systematically searched. A total of 15 studies containing 1698 patients were included in our meta-analysis. The pooled data of studies showed that high OPN expression was significantly associated with high tumor grades (OR = 2.24, 95% CI 1.55–3.23), lymph node metastasis (OR = 2.36, 95% CI 1.71–3.26) and tumor distant metastasis (OR = 2.38, 95% CI 1.01–5.60). Moreover, high OPN expression was significantly associated with the 2-year (HR 1.97, 95% CI 1.30–3.00), 3-year (HR 1.82, 95% CI 1.24–2.68), 5 year (HR 1.53, 95% CI 1.28–1.82) survival rates and overall survival (OS, HR 1.70, 95% CI 1.12–2.60), respectively. These results indicated that OPN could serve as a prognostic biomarker and as a potential therapeutic target for CRC.

Daple is a novel non-receptor GEF required for trimeric G protein activation in Wnt signaling

Wnt signaling is essential for tissue homeostasis and its dysregulation causes cancer. Wnt ligands trigger signaling by activating Frizzled receptors (FZDRs), which belong to the G-protein coupled receptor superfamily. However, the mechanisms of G protein activation in Wnt signaling remain controversial. In this study, we demonstrate that FZDRs activate G proteins and trigger non-canonical Wnt signaling via the Dishevelled-binding protein, Daple. Daple contains a Gα-binding and activating (GBA) motif, which activates Gαi proteins and an adjacent domain that directly binds FZDRs, thereby linking Wnt stimulation to G protein activation. This triggers non-canonical Wnt responses, that is, suppresses the β-catenin/TCF/LEF pathway and tumorigenesis, but enhances PI3K-Akt and Rac1 signals and tumor cell invasiveness. In colorectal cancers, Daple is suppressed during adenoma-to-carcinoma transformation and expressed later in metastasized tumor cells. Thus, Daple activates Gαi and enhances non-canonical Wnt signaling by FZDRs, and its dysregulation can impact both tumor initiation and progression to metastasis.

Post-operative plasma osteopontin predicts distant metastasis in human colorectal cancer

Background

The overall prognosis of colorectal cancer (CRC) patients is unsatisfactory due to cancer metastasis after operation. This study aims to investigate the clinical significance of plasma osteopontin (OPN) levels as minimally invasive, predictive, and surrogate biomarkers for prognosis of CRC patients.

Methods

This randomized study design consists of pre-operative and post-operative plasma samples from a total of 79 patients. We determined plasma levels of OPN by ELISA and examined their correlation with the clinicopathological parameters of CRC patients. The effects of endogenous and exogenous OPN on CRC metastasis were investigated by examination of the effect on regulators of epithelial to messenchymal transition and migration assay.

Results

Our findings demonstrated for the first time the clinical correlation of plasma OPN with metastasis of CRC patients. High post-operative plasma OPN level (>153.02 ng/ml) associated with development of metastasis after curative resection (p<0.001). Moreover, post-operative plasma OPN level correlated with disease-free survival of CRC patients (p=0.009) and was an independent factor for predicting development of metastasis in CRC patients after curative resection (p=0.036). Our in vitro model showed that OPN ectopic expression induced DLD1 cell migration through Snail and Twist1 overexpression and E-cadherin repression, and secretory OPN level enhanced cell migration.

Conclusions

The results of the current study suggest that post-operative plasma OPN correlated with post-operative metastasis, suggesting that it is a potential non-invasive biomarker for the development of future metastasis in CRC patients. In addition, OPN was shown to be involved in the metastatic process and thus inhibition of OPN is a potential therapeutic approach to treat CRC patients.

Heterogeneity analysis of Metastasis Associated in Colon Cancer 1 (MACC1) for survival prognosis of colorectal cancer patients: a retrospective cohort study

Background

Metastasis of colorectal cancer (CRC) is directly linked to patient survival. We previously identified the novel gene Metastasis Associated in Colon Cancer 1 (MACC1) in CRC and demonstrated its importance as metastasis inducer and prognostic biomarker. Here, we investigate the geographic expression pattern of MACC1 in colorectal adenocarcinoma and tumor buds in correlation with clinicopathological and molecular features for improvement of survival prognosis.

Methods

We performed geographic MACC1 expression analysis in tumor center, invasive front and tumor buds on whole tissue sections of 187 well-characterized CRCs by immunohistochemistry. MACC1 expression in each geographic zone was analyzed with Mismatch repair (MMR)-status, BRAF/KRAS-mutations and CpG-island methylation.

Results

MACC1 was significantly overexpressed in tumor tissue as compared to normal mucosa (p < 0.001). Within colorectal adenocarcinomas, a significant increase of MACC1 from tumor center to front (p = 0.0012) was detected. MACC1 was highly overexpressed in 55% tumor budding cells. Independent of geographic location, MACC1 predicted advanced pT and pN-stages, high grade tumor budding, venous and lymphatic invasion (p < 0.05). High MACC1 expression at the invasive front was decisive for prediction of metastasis (p = 0.0223) and poor survival (p = 0.0217). The geographic pattern of MACC1 did not correlate with MMR-status, BRAF/KRAS-mutations or CpG-island methylation.

Conclusion

MACC1 is differentially expressed in CRC. At the invasive front, MACC1 expression predicts best aggressive clinicopathological features, tumor budding, metastasis formation and poor survival outcome.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1150-z) contains supplementary material, which is available to authorized users.

Management of nodal disease from colon cancer in the laparoscopic era

PURPOSE

In colon cancer (CC), nodal involvement is the main prognostic factor following potentially curative (R0) resection. The purpose of this study was to examine data from the literature to provide an up-to-date analysis of the management of nodal disease with special reference to laparoscopic treatment.

METHODS

MEDLINE and EMBASE databases were searched for potentially eligible studies published in English up to July 15, 2014.

RESULTS

In CC, nodal involvement is a frequent event and represents the main risk of cancer recurrence. Node negative patients recur in 10-30 % of cases most likely due to underdiagnosed or undertreated nodal disease. Extended colonic resections (complete mesocolic excision with central vascular ligation; D3 lymphadenectomy) provides a survival benefit and better local control. Sentinel lymph node mapping in addition to standard surgical resection represents an option for improving staging of clinical node negative patients. Both extended resection and sentinel lymph node mapping are feasible in a laparoscopic setting.

CONCLUSIONS

Both extended colonic resection and sentinel lymph node mapping should play a role in the laparoscopic treatment of CC with the purpose of improving control and staging of nodal disease.

High MACC1 expression in combination with mutated KRAS G13 indicates poor survival of colorectal cancer patients

Background

The metastasis-associated in colon cancer 1 (MACC1) gene has been identified as prognostic biomarker for colorectal cancer (CRC). Here, we aimed at the refinement of risk assessment by separate and combined survival analyses of MACC1 expression with any of the markers KRAS mutated in codon 12 (KRAS G12) or codon 13 (KRAS G13), BRAF V600 mutation and MSI status in a retrospective study of 99 CRC patients with tumors UICC staged I, II and III.

Findings

We showed that only high MACC1 expression (HR: 6.09, 95% CI: 2.50-14.85, P < 0.001) and KRAS G13 mutation (HR: 5.19, 95% CI: 1.06-25.45, P = 0.042) were independent prognostic markers for shorter metastasis-free survival (MFS). Accordingly, Cox regression analysis revealed that patients with high MACC1 expression and KRAS G13 mutation exhibited the worst prognosis (HR: 14.48, 95% CI: 3.37-62.18, P < 0.001). Patients were classified based on their molecular characteristics into four clusters with significant differences in MFS (P = 0.003) by using the SPSS 2-step cluster function and Kaplan-Meier survival analysis.

Conclusion

According to our results, patients with high MACC1 expression and mutated KRAS G13 exhibited the highest risk for metachronous metastases formation. Moreover, we demonstrated that the “Traditional pathway” with an intermediate risk for metastasis formation can be further subdivided by assessing MACC1 expression into a low and high risk group with regard to MFS prognosis. This is the first report showing that identification of CRC patients at high risk for metastasis is possible by assessing MACC1 expression in combination with KRAS G13 mutation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0316-2) contains supplementary material, which is available to authorized users.

Tissue inhibitor of metalloproteinases (TIMP)-1 creates a premetastatic niche in the liver through SDF-1/CXCR4-dependent neutrophil recruitment in mice

Due to its ability to inhibit prometastatic matrix metalloproteinases, tissue inhibitor of metalloproteinases (TIMP)-1 has been thought to suppress tumor metastasis. However, elevated systemic levels of TIMP-1 correlate with poor prognosis in cancer patients, suggesting a metastasis-stimulating role of TIMP-1. In colorectal cancer patients, tumor as well as plasma TIMP-1 levels were correlated with synchronous liver metastasis or distant metastasis-associated disease relapse. In mice, high systemic TIMP-1 levels increased the liver susceptibility towards metastasis by triggering the formation of a premetastatic niche. This promoted hepatic metastasis independent of origin or intrinsic metastatic potential of tumor cells. High systemic TIMP-1 led to increased hepatic SDF-1 levels, which in turn promoted recruitment of neutrophils to the liver. Both inhibition of SDF-1-mediated neutrophil recruitment and systemic depletion of neutrophils reduced TIMP-1-induced increased liver susceptibility towards metastasis. This indicates a crucial functional role of neutrophils in the TIMP-1-induced premetastatic niche.

CONCLUSION

Our results identify TIMP-1 as an essential promoter of hepatic premetastatic niche formation.

MACC1 overexpression and survival in solid tumors: a meta-analysis

Metastasis associated in colon cancer-1 (MACC1) is a newly identified oncogene, and increasing evidence has suggested that its overexpression is associated with the development and progression in many tumors. Here, we perform a meta-analysis to assess the relationship between MACC1 overexpression and survival in solid tumors. Eligible studies were searched in Embase, PubMed, and Web of Science databases up to May 2014. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to estimate the impact of MACC1 overexpression on survival using a random-effect model. A total of 20 eligible studies dealing with various tumors were included in the analysis: 17 were dealing with overall survival (OS), 7 were with relapse-free survival (RFS), and 3 were with disease-free survival (DFS). Combined results suggested a strong link between the high MACC1 expression and the poor overall survival (HR 2.11, 95% CI 1.59-2.80, P < 0.001). For relapse-free survival, overexpressed MACC1 was also a significant predictor, with a combined HR of 2.22 (95% CI 1.80-2.74, P < 0.001). Data from the three studies were combined to show that MACC1 overexpression had also an unfavorable impact on disease-free survival (HR 2.94, 95% CI 1.60-5.38, P < 0.001). Publication bias was not significant. The present meta-analysis showed that overexpression of MACC1 was significantly associated with poorer survival in solid tumors.

Long-term results after proactive management for locoregional control in patients with colonic cancer at high risk of peritoneal metastases

PURPOSE

A major problem in treating patients with peritoneal spread from colorectal cancer is that at diagnosis wide peritoneal involvement often precludes all curative attempts. A possible solution is to identify those patients at risk for peritoneal metastases and intervene early to prevent locoregional disease spread before it develops and, thus, to improve outcome.

METHODS

We analyzed long-term results from a previous study and compared outcomes in 25 patients with advanced colon cancer considered at high risk for peritoneal spread (pT3/pT4 and mucinous or signet ring cell histology) prospectively included and managed with a proactive surgical approach including target organ resection for peritoneal spread plus hyperthermic intraperitoneal chemotherapy (HIPEC) and in 50 retrospectively well-matched controls who underwent standard surgical resection during the same period and in the same hospital by different surgical teams.

RESULTS

At 48 months after the study closed, peritoneal metastases and local recurrence developed significantly less often in proactively managed patients than in controls (4 vs 28%) (p < 0.03). Patients in the proactive group also survived longer than control patients (median overall survival 59.5 vs 52 months). Despite similar morbidity, Kaplan-Meier survival curves disclosed significantly longer disease-free and overall survival in the proactive than in the control group (p < 0.05 and <0.04).

CONCLUSIONS

In patients with advanced colon cancer at risk for peritoneal recurrence, the proactive surgical approach plus HIPEC seems to achieve good locoregional control preventing peritoneal spread thus improving outcome without increasing morbidity. These advantages merit investigation in a multicentric randomized trial.

Molecular staging of lymph node-negative colon carcinomas by one-step nucleic acid amplification (OSNA) results in upstaging of a quarter of patients in a prospective, European, multicentre study

Background:

Current histopathological staging procedures in colon carcinomas depend on midline division of the lymph nodes with one section of haematoxylin & eosin (H&E) staining only. By this method, tumour deposits outside this transection line may be missed and could lead to understaging of a high-risk group of stage UICC II cases, which recurs in ∼20% of cases. A new diagnostic semiautomated system, one-step nucleic acid amplification (OSNA), detects cytokeratin (CK) 19 mRNA in lymph node metastases and enables the investigation of the whole lymph node. The objective of this study was to assess whether histopathological pN0 patients can be upstaged to stage UICC III by OSNA.

Methods:

Lymph nodes from patients who were classified as lymph node negative after standard histopathology (single (H&E) slice) were subjected to OSNA. A result revealing a CK19 mRNA copy number >250, which makes sure to detect mainly macrometastases and not isolated tumour cells (ITC) or micrometastases only, was regarded as positive for lymph node metastases based on previous threshold investigations.

Results:

In total, 1594 pN0 lymph nodes from 103 colon carcinomas (median number of lymph nodes per patient: 14, range: 1–46) were analysed with OSNA. Out of 103 pN0 patients, 26 had OSNA-positive lymph nodes, resulting in an upstaging rate of 25.2%. Among these were 6/37 (16.2%) stage UICC I and 20/66 (30.3%) stage UICC II patients. Overall, 38 lymph nodes were OSNA positive: 19 patients had one, 3 had two, 3 had three, and 1 patient had four OSNA-positive lymph nodes.

Conclusions:

OSNA resulted in an upstaging of over 25% of initially histopathologically lymph node-negative patients. OSNA is a standardised, observer-independent technique, allowing the analysis of the whole lymph node. Therefore, sampling bias due to missing investigation of certain lymph node tissue can be avoided, which may lead to a more accurate staging.

Activation of the PI3K/AKT pathway correlates with prognosis in stage II colon cancer

Background:

Patients with UICC/AJCC stage II colon cancer have a high 5-year overall survival rate after surgery. Nevertheless, a significant subgroup of patients develops tumour recurrence. Currently, there are no clinically established biomarkers available to identify this patient group. We applied reverse-phase protein arrays (RPPA) for phosphatidylinositide-3-kinase pathway activation mapping to stratify patients according to their risk of tumour recurrence after surgery.

Methods:

Full-length proteins were extracted from formalin-fixed, paraffin-embedded tissue samples of 118 patients who underwent curative resection. RPPA technology was used to analyse expression and/or phosphorylation levels of six major factors of the phosphatidylinositide-3-kinase pathway. Oncogenic mutations of KRAS and BRAF, and DNA microsatellite status, currently discussed as prognostic markers, were analysed in parallel.

Results:

Expression of phospho-AKT (HR=3.52; P=0.032), S6RP (HR=6.3; P=0.044), and phospho-4E-BP1 (HR=4.12; P=0.011) were prognostic factors for disease-free survival. None of the molecular genetic alterations were significantly associated with prognosis.

Conclusions:

Our data indicate that activation of the PI3K/AKT pathway evidenced on the protein level might be a valuable prognostic marker to stratify patients for their risk of tumour recurrence. Beside adjuvant chemotherapy targeting of upregulated PI3K/AKT signalling may be an attractive strategy for treatment of high-risk patients.

Colorectal cancer surgery remains effective with rising patient age

BACKGROUND

The incidence of colorectal cancer rises disproportionally in aging persons. With a shift towards higher population age in general, an increasing number of older patients require adequate treatment. This study aims to investigate differences between young and elderly patients who undergo resection for colorectal cancer, regarding clinical characteristics, morbidity, and prognosis.

METHODS

By retrospective analysis of 6 years (2007 to 2012) of a prospectively documented database, a total of 636 patients were identified who underwent oncological resection for colorectal cancer at our institution. Of this total, all 569 patients with primary colorectal adenocarcinoma were included. Four hundred ten patients were 74 years or younger and 159 were 75 years or older. The median follow-up was 22 months.

RESULTS

Older patients had significantly more comorbidities (85 % vs. 56 %, p < 0.001) and a higher ASA score (p < 0.001). The mean length of stay in the hospital was longer (24 vs. 20 days, p = 0.002), as was the length of postoperative intensive care stay (4 vs. 2 days, p = 0.003). However, elderly patients did not have significantly higher rates of intraoperative complications or surgical morbidity. Tumor-specific 2-year survival was 83 ± 4 % for the elderly and 87 ± 2 % for the younger patients, which was not significantly different (p = 0.90).

CONCLUSIONS

Long-term outcome after oncologic resection for colorectal cancer does not differ between elderly and younger patients. Age in general should not be considered as a limiting factor for colorectal cancer surgery or tumor-specific prognosis.