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

Induction of circulating ABCB1 transcripts under platinum-based chemotherapy indicates poor prognosis and a bone micrometastatic phenotype in ovarian cancer patients

The drug efflux transporter P-glycoprotein, encoded by the ABCB1 gene, promotes acquired chemoresistance. We explored the presence and clinical relevance of circulating cell-free ABCB1 transcripts (cfABCB1tx) in ovarian cancer patients (173 longitudinal serum samples from 79 cancer patients) using digital droplet PCR. cfABCB1tx were readily detectable at primary diagnosis (median 354 mRNA copies/20 µl serum), paralleled FIGO-stage and predicted surgical outcome (p = 0.023, p=0.022, respectively). Increased cfABCB1tx levels at primary diagnosis indicated poor PFS (HR = 2.329, 95%CI:1.374-3.947, p = 0.0017) and OS (HR = 2.074, 95%CI:1.194-3.601, p = 0.0096). cfABCB1tx induction under platinum-based chemotherapy was an independent predictor for poor OS (HR = 2.597, 95%CI: 1.218-5.538, p = 0.013) and paralelled a micrometastatic phenotype, shaped by the presence of disseminated tumor cells in the bone marrow. A strong correlation was observed between cfABCB1tx and circulating transcripts of the metastasis-inducer MACC1, which is the transcriptional activator of ABCB1. Combined assessment of cfABCB1tx and circulating cell-free MACC1 transcripts (cfMACC1tx) resulted in an improved prognostic prediction, with  the cfABCB1tx-high/cfMACC1tx-high phenotype bearing the highest risk for relapse and death. Conclusively, we provide proof of principle, that ABCB1 transcripts are readily traceable in the liquid-biopsy of ovarian cancer patients, advancing a new dimension for systemic monitoring of ABCB1/P-glycoprotein expression dynamics.

Global Proteomics Analysis of Lysophosphatidic Acid Signaling in PC-3 Human Prostate Cancer Cells: Role of CCN1

Cysteine-rich angiogenic factor 61 (CCN1/Cyr61) is a matricellular protein that is induced and secreted in response to growth factors. Our previous work showed that 18:1-lysophosphatidic acid (LPA), which activates the G protein-coupled receptor LPAR1, induces CCN1 between 2-4 h in PC-3 human prostate cancer cells in a manner than enhances cell-substrate adhesion. While the time course of induction suggests that CCN1 contributes to intermediate events in LPA action, the roles of CCN1 in LPA-mediated signal transduction have not been fully elucidated. This study utilized a comprehensive global proteomics approach to identify proteins up- or down-regulated in response to treatment of PC-3 cells with LPA for three hours, during the time of peak CCN1 levels. In addition, the effects of siRNA-mediated CCN1 knockdown on LPA responses were analyzed. The results show that, in addition to CCN1, LPA increased the levels of multiple proteins. Proteins up-regulated by LPA included metastasis-associated in colon cancer protein 1 (MACC1) and thrombospondin-1 (TSP1/THBS1); both MACC1 and TSP1 regulated cancer cell adhesion and motility. LPA down-regulated thioredoxin interacting protein (TXNIP). CCN1 knockdown suppressed the LPA-induced up-regulation of 30 proteins; these included MACC1 and TSP1, as confirmed by immunoblotting. Gene ontology and STRING analyses revealed multiple pathways impacted by LPA and CCN1. These results indicate that CCN1 contributes to LPA signaling cascades that occur during the intermediate phase after the initial stimulus. The study provides a rationale for the development of interventions to disrupt the LPA-CCN1 axis.

MACC1-induced migration in tumors: Current state and perspective

Malignant tumors are still a global, heavy health burden. Many tumor types cannot be treated curatively, underlining the need for new treatment targets. In recent years, metastasis associated in colon cancer 1 (MACC1) was identified as a promising biomarker and drug target, as it is promoting tumor migration, initiation, proliferation, and others in a multitude of solid cancers. Here, we will summarize the current knowledge about MACC1-induced tumor cell migration with a special focus on the cytoskeletal and adhesive systems. In addition, a brief overview of several in vitro models used for the analysis of cell migration is given. In this context, we will point to issues with the currently most prevalent models used to study MACC1-dependent migration. Lastly, open questions about MACC1-dependent effects on tumor cell migration will be addressed.

MACC1 Correlates with Tumor Progression and Immune Cell Infiltration of Colon Adenocarcinoma and is Regulated by the lncRNA ZFAS1/miR-642a-5p Axis

Colon adenocarcinoma (COAD) is the most common pathologic type of colon cancer. Metastasis is responsible for the high mortality rate of patients with COAD. The gene, metastasis-associated in colon cancer 1 (MACC1), is a biomarker predictive of both metastatic and metastasis-free survival in patients with colon cancer and other solid tumors. However, the underlying mechanism by which MACC1 affect COAD progression and metastasis remains unknown. In this study, we analyzed the expression level and prognostic value of MACC1, as well as their correlation, in patients with various types of cancer included in The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. High MACC1 expression was found to be significantly associated with poor prognosis in patients with COAD. Analysis of the potential upstream miRNA of MACC1 showed that miR-642a-5p was downregulated in COAD and was negatively correlated with MACC1 expression. Analysis of the upstream regulators of miR-642a-5p showed that the long non-coding RNA (lncRNA) ZFAS1was the most likely upstream regulator of miR-642a-5p. In addition, the expression of MACC1 correlated positively with tumor immune cell infiltration, as well as with the levels of biomarkers of five kinds of immune cells. In summary, these findings suggest that MACC1 contributes to COAD progression and immune cell infiltration via the ZFAS1/miR-642a-5p/MACC1 axis.

Obesity, colorectal cancer and MACC1 expression: A possible novel molecular association

Obesity is a major and increasing public health concern, associated with an increased risk of and mortality from several types of cancer including colorectal cancer (CRC), being associated with cancer progression, metastasis and resistance to therapy. It was hypothesized that the expression of cancer/metastasis-inducing gene metastasis-associated in colon cancer 1 (MACC1) is increased in obesity, which may constitute a link to obesity-induced cancer. The present study thus analyzed circulating cell-free plasma MACC1 expression levels in human obese (vs. normal weight) adult individuals from independent studies, namely the Martin Luther University (MLU) study (n=32) and the Metabolic syndrome study (MetScan, Berlin) (n=191). Higher plasma MACC1 levels were found in obese individuals, increasing with a greater body fat mass and body mass index; these levels were predominantly observed in male and to a lesser extent in female individuals, although the results were not significant. A reduction in body fat mass following dietary intervention and physical exercise decreased the MACC1 expression levels in the MLU study. Furthermore, Wistar rats with diet-induced obesity exhibited slightly increased plasma MACC1 levels compared with rats of normal weight. The obese Wistar rats exposed to azoxymethane to induce colon cancer exhibited a more severe colon tumor outcome, which was associated with significantly increased MACC1 levels compared with their non-obese littermates. On the whole, the findings of the present study suggest an association between MACC1 and obesity, as well as with obesity-induced CRC.

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.

MACC1 Contributes to the Development of Osteosarcoma Through Regulation of the HGF/c-Met Pathway and Microtubule Stability

Osteosarcoma (OS) is the most prevalent human bone malignancy, and presents a global annual morbidity of approximately five cases per million. Notably, precise and efficient targeted therapy has become the most promising strategy for the treatment of OS; however, there is still an urgent need for the identification of suitable therapeutic targets. Metastasis-associated in colon cancer 1 (MACC1) was first identified in colon tumors by differential display RT-PCR, and was shown to be involved in the regulation of colon tumor growth and metastasis through the hepatocyte growth factor (HGF)/c-Met signaling pathway. Additionally, MACC1 overexpression has been reported to induce the growth of several types of cancers, including glioblastoma multiforme and gastric cancer. However, whether MACC1 also plays a role in the progression of OS remains unclear. In this study, we found that MACC1 was highly expressed in human OS tissues, as well as in U-2OS and MG-63 cells, when compared with normal tissues and osteoblasts, respectively. Our data further indicated that MACC1 expression was correlated with several clinicopathological features of OS. Through in vitro assays, we found that MACC1 depletion markedly suppressed the proliferative ability of both OS cells and endothelial cells, and inhibited the angiogenic capacity of endothelial cells. Similarly, MACC1 depletion inhibited tumor growth, metastasis, and angiogenesis in mice. Mechanistically, we found that MACC1 could bind to the MET promoter, and enhanced the proliferation of both OS cells and endothelial cells through the HGF/c-Met signaling pathway. Furthermore, we show that MACC1 also promoted angiogenesis by regulating microtubule dynamics, thereby promoting the progression of OS. Our results indicate that MACC1 may be a new and promising therapeutic target for the treatment of OS.

Pro-inflammatory TNF-α and IFN-γ Promote Tumor Growth and Metastasis via Induction of MACC1

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Early stage CRC patients have a good prognosis. If distant metastasis occurs, the 5-year survival drops below 10%. Despite treatment success over the last decades, treatment options for metastatic disease are still limited. Therefore, novel targets are needed to foster therapy of advanced stage CRC patients and hinder progression of early stage patients into metastasis. A novel target is the crucial oncogene Metastasis-Associated in Colon Cancer 1 (MACC1) involved in molecular pathogenesis of CRC metastasis. MACC1 induces cell proliferation and motility, supports cellular survival and rewires metabolism resulting in increased metastasis in vivo. MACC1 is a prognostic biomarker not only for CRC but for more than 20 solid cancer entities. Inflammation plays a pivotal role in tumorigenesis, tumor progression and metastasis. For CRC, inflammatory bowel disease and ulcerative colitis are important inflammation associated risk factors. Certain cytokines, such as TNF-α and IFN-γ, are key factors in determining the contribution of the inflammatory process to CRC. Knowledge of the connection between inflammation and MACC1 driven tumors remains unclear. Gene expression analysis of CRC cells after cytokine stimulation was analyzed by qRT-PCR and Western blot. Cellular motility was assessed by Boyden chamber assays. MACC1 promoter activity after stimulation with pro-inflammatory cytokines was measured using promoter-luciferase constructs. To investigate signal transduction from receptor to effector molecules, blocking experiments using neutralizing antibodies and knockdown experiments were performed. Following TNF-α stimulation, MACC1 and c-Jun expression were significantly increased at the mRNA and protein level. Knockdown of c-Jun reduced MACC1 inducibility following TNF-α stimulation. TNF-α promoted MACC1-induced cell migration that was reverted following MACC1 knockdown. Moreover, MACC1 and c-Jun expression were downregulated by blocking TNFR1, but not TNFR2. Knock down of the NF-κB subunit, p65, reduced basal MACC1 and c-Jun mRNA expression levels. Adalimumab, a clinically approved monoclonal anti-TNF-α antibody, hindered MACC1 induction. The present study highlights that TNF-α regulates the induction of MACC1 via the NF-κB subunit p65 and the transcription factor c-Jun in CRC cells. This finding unravels a novel signaling pathway upstream of MACC1 and provides a potential therapeutic target for the treatment of CRC patients with an associated inflammation.

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.

miR-338-3p regulates the proliferation, apoptosis and migration of SW480 cells by targeting MACC1

The mortality and incidence rates of colorectal cancer (CRC) vary widely worldwide. miR-338-3p inhibits tumor cell proliferation in several types of cancer, however, the role of miR-338-3p on CRC remains unknown. The aim of the current study was to investigate the cellular function of miRNA-338-3p (miR-338-3p) in CRC, the malignant behavior of CRC cells and the interaction between miR-338-3p and metastasis-associated in colon cancer-1 (MACC1). miR-338-3p expression was significantly decreased in CRC tissue compared with adjacent normal tissue. In the CRC cell line SW480, miR-338-3p overexpression suppressed cell proliferation and migration and induced G1/S cell cycle arrest and apoptosis. By contrast, miR-338-3p knockdown significantly enhanced cell proliferation and migration, and suppressed G1/S cell cycle arrest and apoptosis. Furthermore, the dual-luciferase reporter assay confirmed MACC1 as a direct target of miR-338-3p. In addition, miR-338-3p overexpression reduced the level of MACC1 protein expression and MACC1 expression was significantly upregulated in CRC tissue samples. MACC1 siRNA significantly reduced CRC cell proliferation and migration, whilst cell apoptosis was significantly increased. In conclusion, miR-338-3p expression was decreased in CRC. miR-338-3p regulated the proliferation, apoptosis and migration of CRC cells by targeting MACC1.

Diagnostic and prognostic value of serum MACC1 in breast cancer patients

Metastasis-associated in colon cancer-1 (MACC1) promotes colorectal cancer progression and predicts prognosis. The aim of our study was to determine the diagnostic and prognostic value of preoperative serum MACC1 levels in breast cancer patients. Serum MACC1 levels were measured in 378 breast cancer patients, 120 patients with benign breast disease, and 40 healthy volunteers using an ELISA. Serum MACC1 levels were higher in breast cancer patients than patients with benign disease or healthy volunteers. Increased serum MACC1 was associated with breast cancer TNM stage (P < 0.001), tumor size (P < 0.001), lymph node metastasis (P < 0.001), and Ki-67 status (P = 0.014). Serum MACC1 measurement successfully discriminated breast cancer patients from normal and healthy controls (AUC = 0.785, 95% CI: 0.746–0.825) with an optimal cut-off value of 38.35 pg/ml (sensitivity = 0.725, specificity = 0.696). Moreover, serum MACC1 exhibited significant prognostic value in breast cancer (AUC = 0.757, 95% CI: 0.700–0.814), and high MACC1 was associated with poor disease-free survival (HR 5.63, 95% CI: 3.51–9.04; P < 0.001). Our findings demonstrated that circulating MACC1 could serve as a reliable diagnostic and prognostic biomarker for breast cancer.