FOXC2 promotes colorectal cancer metastasis by directly targeting MET

Xanthohumol overcomes osimertinib resistance via governing ubiquitination-modulated Ets-1 turnover

Non-small cell lung cancer (NSCLC) is a prevalent and fatal malignancy with a significant global impact. Recent advancements have introduced targeted therapies like tyrosine kinase inhibitors (TKIs) such as osimertinib, which have improved patient outcomes, particularly in those with EGFR mutations. Despite these advancements, acquired resistance to TKIs remains a significant challenge. Hence, one of the current research priorities is understanding the resistance mechanisms and identifying new therapeutic targets to improve therapeutic efficacy. Herein, we identified high expression of c-Met in osimertinib-resistant NSCLC cells, and depletion of c-Met significantly inhibited the proliferation of osimertinib-resistant cells and prolonged survival in mice, suggesting c-Met as an attractive therapeutic target. To identify effective anti-tumor agents targeting c-Met, we screened a compound library containing 641 natural products and found that only xanthohumol exhibited potent inhibitory effects against osimertinib-resistant NSCLC cells. Moreover, combination treatment with xanthohumol and osimertinib sensitized osimertinib-resistant NSCLC cells to osimertinib both in vitro and in vivo. Mechanistically, xanthohumol disrupted the interaction between USP9X and Ets-1, and inhibited the phosphorylation of Ets-1 at Thr38, promoting its degradation, thereby targeting the Ets-1/c-Met signaling axis and inducing intrinsic apoptosis in osimertinib-resistant NSCLC cells. Overall, the research highlights the critical role of targeting c-Met to address osimertinib resistance in NSCLC. By demonstrating the efficacy of xanthohumol in overcoming resistance and enhancing therapeutic outcomes, this study provides valuable insights and potential new strategies for improving the clinical management of NSCLC.

MicroRNAs as the critical regulators of Forkhead box protein family during gynecological and breast tumor progression and metastasis

Gynecological and breast tumors are one of the main causes of cancer-related mortalities among women. Despite recent advances in diagnostic and therapeutic methods, tumor relapse is observed in a high percentage of these patients due to the treatment failure. Late diagnosis in advanced tumor stages is one of the main reasons for the treatment failure and recurrence in these tumors. Therefore, it is necessary to assess the molecular mechanisms involved in progression of these tumors to introduce the efficient early diagnostic markers. Fokhead Box (FOX) is a family of transcription factors with a key role in regulation of a wide variety of cellular mechanisms. Deregulation of FOX proteins has been observed in different cancers. MicroRNAs (miRNAs) as a group of non-coding RNAs have important roles in post-transcriptional regulation of the genes involved in cellular mechanisms. They are also the non-invasive diagnostic markers due to their high stability in body fluids. Considering the importance of FOX proteins in the progression of breast and gynecological tumors, we investigated the role of miRNAs in regulation of the FOX proteins in these tumors. MicroRNAs were mainly involved in progression of these tumors through FOXM, FOXP, and FOXO. The present review paves the way to suggest a non-invasive diagnostic panel marker based on the miRNAs/FOX axis in breast and gynecological cancers.

Unraveling the function of epithelial-mesenchymal transition (EMT) in colorectal cancer: Metastasis, therapy response, and revisiting molecular pathways

Colorectal cancer (CRC) is a dangerous form of cancer that affects the gastrointestinal tract. It is a major global health concern, and the aggressive behavior of tumor cells makes it difficult to treat, leading to poor survival rates for patients. One major challenge in treating CRC is the metastasis, or spread, of the cancer, which is a major cause of death. In order to improve the prognosis for patients with CRC, it is necessary to focus on ways to inhibit the cancer's ability to invade and spread. Epithelial-mesenchymal transition (EMT) is a process that is linked to the spread of cancer cells, also known as metastasis. The process transforms epithelial cells into mesenchymal ones, increasing their mobility and ability to invade other tissues. This has been shown to be a key mechanism in the progression of colorectal cancer (CRC), a particularly aggressive form of gastrointestinal cancer. The activation of EMT leads to increases in the spread of CRC cells, and during this process, levels of the protein E-cadherin decrease while levels of N-cadherin and vimentin increase. EMT also contributes to the development of resistance to chemotherapy and radiation therapy in CRC. Non-coding RNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), play a role in regulating EMT in CRC, often through their ability to "sponge" microRNAs. Anti-cancer agents have been shown to suppress EMT and reduce the progression and spread of CRC cells. These findings suggest that targeting EMT or related mechanisms may be a promising approach for treating CRC patients in the clinic.

Formin-like 2 promotes angiogenesis and metastasis of colorectal cancer by regulating the EGFL6/CKAP4/ERK axis

Increasing evidence indicates that angiogenesis plays a pivotal role in tumor progression. Formin-like 2 (FMNL2) is well-known for promoting metastasis; however, the molecular mechanisms by which FMNL2 promotes angiogenesis in colorectal cancer (CRC) remain unclear. Here, we found that FMNL2 promotes angiogenesis and metastasis of CRC in vitro and in vivo. The GDB/FH3 domain of FMNL2 directly interacts with epidermal growth factor-like protein 6 (EGFL6). Formin-like 2 promotes EGFL6 paracrine signaling by exosomes to regulate angiogenesis in CRC. Cytoskeleton associated protein 4 (CKAP4) is a downstream target of EGFL6 and is involved in CRC angiogenesis. Epidermal growth factor-like protein 6 binds to the N-terminus of CKAP4 to promote the migration of HUVECs by activating the ERK/MMP pathway. These findings suggest that FMNL2 promotes the migration of HUVECs and enhances angiogenesis and tumorigenesis in CRC by regulating the EGFL6/CKAP4/ERK axis. Therefore, the EGFL6/CKAP4/ERK axis could be a candidate therapeutic target for CRC treatment.

Oncogenic functions of the FOXC2 transcription factor: a hallmarks of cancer perspective

Epigenetic regulation of gene expression is a fundamental determinant of molecular and cellular function, and epigenetic reprogramming in the context of cancer has emerged as one of the key enabling characteristics associated with acquisition of the core hallmarks of this disease. As such, there has been renewed interest in studying the role of transcription factors as epigenetic regulators of gene expression in cancer. In this review, we discuss the current state of knowledge surrounding the oncogenic functions of FOXC2, a transcription factor that frequently becomes dysregulated in a variety of cancer types. In addition to highlighting the clinical impact of aberrant FOXC2 activity in cancer, we discuss mechanisms by which this transcription factor becomes dysregulated in both tumor and tumor-associated cells, placing particular emphasis on the ways in which FOXC2 promotes key hallmarks of cancer progression. Finally, we bring attention to important issues related to the oncogenic dysregulation of FOXC2 that must be addressed going forward in order to improve our understanding of FOXC2-mediated cancer progression and to guide prognostic and therapeutic applications of this knowledge in clinical settings.

HSF4 promotes tumor progression of colorectal cancer by transactivating c-MET

Heat shock factors (HSFs) are a family of transcription factors, composed of HSF1, HSF2, and HSF4, to regulate cell stress reaction for maintaining cellular homeostasis in response to adverse stimuli. Recent studies have disclosed the roles of HSF1 and HSF2 in modulating tumor development, including colorectal cancer (CRC). However, HSF4, which is closely associated with pathology of congenital cataracts, remains less studied in tumors. In this study, we aimed to describe the regulatory effects of HSF4 and underlying molecular mechanism in CRC progression. By bioinformatic analysis of TCGA database and TMA-IHC assay, we identified that the expression of HSF4 was significantly upregulated in CRCs compared with normal colonic tissues and was a prognostic factor of poor outcomes of CRC patients. Function assays, including CCK-8, colony formation, transwell assays, and xenografted mouse model, were employed to verify that HSF4 promoted cell growth, colony formation, invasion of CRC cells in vitro, and tumor growth in vivo as a potential oncogenic factor. Mechanistically, results of Chromatin immunoprecipitation (ChIP) and immunoblotting assays revealed that HSF4 associated directly to MET promoter to enhance expression of c-MET, a well-known oncogene in multiple cancers, thus fueling the activity of downstream ERK1/2 and AKT signaling pathways. In further rescue experiments, restoration of c-MET expression abolished inhibitory cell growth and invasion induced by downregulated HSF4 expression. To sum up, our findings describe a crucial role of HSF4 in CRC progression by enhancing activity of c-MET and downstream ERK1/2 and AKT signaling pathways, and highlight HSF4 as a potential therapeutic target for anti-CRC treatment.

Reduction of Metastasis via Epigenetic Modulation in a Murine Model of Metastatic Triple Negative Breast Cancer (TNBC)

This study investigates the effects of a dual selective Class I histone deacetylase (HDAC)/lysine-specific histone demethylase 1A (LSD1) inhibitor known as 4SC-202 (Domatinostat) on tumor growth and metastasis in a highly metastatic murine model of Triple Negative Breast Cancer (TNBC). 4SC-202 is cytotoxic and cytostatic to the TNBC murine cell line 4T1 and the human TNBC cell line MDA-MB-231; the drug does not kill the normal breast epithelial cell line MCF10A. Furthermore, 4SC-202 reduces cancer cell migration. In vivo studies conducted in the syngeneic 4T1 model, which closely mimics human TNBC in terms of sites of metastasis, reveal reduced tumor burden and lung metastasis. The mechanism of action of 4SC-202 may involve effects on cancer stem cells (CSC) which can self-renew and form metastatic lesions. Approximately 5% of the total 4T1 cell population grown in three-dimensional scaffolds had a distinct CD44high/CD24low CSC profile which decreased after treatment. Bulk transcriptome (RNA) sequencing analyses of 4T1 tumors reveal changes in metastasis-related pathways in 4SC-202-treated tumors, including changes to expression levels of genes implicated in cell migration and cell motility. In summary, 4SC-202 treatment of tumors from a highly metastatic murine model of TNBC reduces metastasis and warrants further preclinical studies.

Colorectal liver metastasis: molecular mechanism and interventional therapy

Colorectal cancer (CRC) is one of the most frequently occurring malignancy tumors with a high morbidity additionally, CRC patients may develop liver metastasis, which is the major cause of death. Despite significant advances in diagnostic and therapeutic techniques, the survival rate of colorectal liver metastasis (CRLM) patients remains very low. CRLM, as a complex cascade reaction process involving multiple factors and procedures, has complex and diverse molecular mechanisms. In this review, we summarize the mechanisms/pathophysiology, diagnosis, treatment of CRLM. We also focus on an overview of the recent advances in understanding the molecular basis of CRLM with a special emphasis on tumor microenvironment and promise of newer targeted therapies for CRLM, further improving the prognosis of CRLM patients.

FOXC2/ADAM12-dependent radiosensitivity of head and neck squamous cell carcinoma cells

BACKGROUND

Radiotherapy greatly benefits patients with tumors, but not all patients show favorable treatment response. This study investigated the impact of forkhead box protein C2 (FOXC2)-mediated a disintegrin and metalloprotease 12 (ADAM12) on the radiosensitivity of head and neck squamous cell carcinoma (HNSCC).

METHODS

After transfection and ionizing radiation, the biological activities of HNSCC cells were assessed. The relationship between ADAM12 and FOXC2 was verified. A xenograft model was used to evaluate the effect of FOXC2 knockdown on HNSCC growth in the context of radiation therapy.

RESULTS

FOXC2 and ADAM12 were upregulated in irradiated CAL-27 and HN4 cells. Knockdown of FOXC2 suppressed the malignant behaviors of CAL-27 and HN4 cells and inhibited the growth of transplanted tumors in nude mice. FOXC2 could bind ADAM12 promoter. Overexpression of ADAM12 reversed the promotion of FOXC2 silencing on the radiosensitivity of HNSCC cells.

CONCLUSIONS

FOXC2 regulates the radiosensitivity of HNSCC by targeting ADAM12.

Tumor cell-derived SPON2 promotes M2-polarized tumor-associated macrophage infiltration and cancer progression by activating PYK2 in CRC

Background

Tumor-associated macrophages (TAMs) are key regulators of the complex interplay between cancer and the immune microenvironment. Tumor cell-derived spondin 2 (SPON2) is an extracellular matrix glycoprotein that has complicated roles in recruitment of macrophages and neutrophils during inflammation. Overexpression of SPON2 has been shown to promote tumor cell migration in colorectal cancer (CRC). However, the mechanism by which SPON2 regulates the accumulation of TAMs in the tumor microenvironment (TME) of CRC is unknown.

Methods

Immunohistochemistry was used to examine SPON2 expression in clinical CRC tissues. In vitro migration assays, transendothelial migration assays (iTEM), and cell adhesion assays were used to investigate the effects of SPON2 on monocyte/macrophage migration. Subcutaneous tumor formation and orthotopic implantation assays were performed in C57 BL/6 mice to confirm the effects of SPON2 on TAM infiltration in tumors.

Results

SPON2 expression is positively correlated with M2-TAM infiltration in clinical CRC tumors and poor prognosis of CRC patients. In addition, SPON2 promotes cytoskeletal remodeling and transendothelial migration of monocytes by activating integrin β1/PYK2 axis. SPON2 may indirectly induce M2-polarization through upregulating cytokines including IL10, CCL2 and CSF1 expression in tumor cells. Blocking M2 polarization and Macrophage depletion inhibited the SPON2-induced tumors growth and invasion. Furthermore, blocking the SPON2/integrin β1/PYK2 axis impairs the transendothelial migration of monocytes and cancer-promoting functions of TAMs in vivo.

Conclusions

Our findings demonstrate that SPON2-driven M2-TAM infiltration plays an important role during CRC tumor growth and metastasis. SPON2 may be a valuable biomarker guiding the use of macrophage-targeting strategies and a potential therapeutic target in advanced CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02108-0.

Regulation of Wnt Signaling by FOX Transcription Factors in Cancer

Simple Summary

Cancer is caused by a breakdown of cell-to-cell communication, which results in the unrestricted expansion of cells within a tissue. In many cases, tumor growth is maintained by the continuous activation of cell signaling programs that normally drive embryonic development and wound repair. In this review article, I discuss how one of the largest human protein families, namely FOX proteins, controls the activity of the Wnt pathway, a major regulatory signaling cascade in developing organisms and adult stem cells. Evidence suggests that there is considerable crosstalk between FOX proteins and the Wnt pathway, which contributes to cancer initiation and progression. A better understanding of FOX biology may therefore lead to the development of new targeted treatments for many types of cancer.

Abstract

Aberrant activation of the oncogenic Wnt signaling pathway is a hallmark of numerous types of cancer. However, in many cases, it is unclear how a chronically high Wnt signaling tone is maintained in the absence of activating pathway mutations. Forkhead box (FOX) family transcription factors are key regulators of embryonic development and tissue homeostasis, and there is mounting evidence that they act in part by fine-tuning the Wnt signaling output in a tissue-specific and context-dependent manner. Here, I review the diverse ways in which FOX transcription factors interact with the Wnt pathway, and how the ectopic reactivation of FOX proteins may affect Wnt signaling activity in various types of cancer. Many FOX transcription factors are partially functionally redundant and exhibit a highly restricted expression pattern, especially in adults. Thus, precision targeting of individual FOX proteins may lead to safe treatment options for Wnt-dependent cancers.

Super-enhancer Acquisition Drives FOXC2 Expression in Middle Ear Cholesteatoma

Distinct histone modifications regulate gene expression in certain diseases, but little is known about histone epigenetics in middle ear cholesteatoma. It is known that histone acetylation destabilizes the nucleosome and chromatin structure and induces gene activation. The association of histone acetylation with chronic inflammatory diseases has been indicated in recent studies. In this study, we examined the localization of variously modified histone H3 acetylation at lysine 9, 14, 18, 23, and 27 in paraffin-embedded sections of human middle ear cholesteatoma (cholesteatoma) tissues and the temporal bones of an animal model of cholesteatoma immunohistochemically. As a result, we found that there was a significant increase of the expression levels of H3K27ac both in human cholesteatoma tissues and the animal model. In genetics, super-enhancers are clusters of enhancers that drive the transcription of genes involved in cell identity. Super-enhancers were originally defined using the H3K27ac signal, and then we used H3K27ac chromatin immunoprecipitation followed by sequencing to map the active cis-regulatory landscape in human cholesteatoma. Based on the results, we identified increased H3K27ac signals as super-enhancers of the FOXC2 loci, as well as increased protein of FOXC2 in cholesteatoma. Recent studies have indicated that menin-MLL inhibitor could suppress tumor growth through the control of histone H3 modification. In this study, we demonstrated that the expression of FOXC2 was inhibited by menin-MLL inhibitor in vivo. These findings indicate that FOXC2 expression under histone modifications promoted the pathogenesis of cholesteatoma and suggest that it may be a therapeutic target of cholesteatoma.

FOXC2 Autoregulates Its Expression in the Pulmonary Endothelium After Endotoxin Stimulation in a Histone Acetylation-Dependent Manner

The innate immune response of pulmonary endothelial cells (EC) to lipopolysaccharide (LPS) induces Forkhead box protein C2 (FOXC2) activation through Toll Like Receptor 4 (TLR4). The mechanisms by which FOXC2 expression is regulated in lung EC under LPS stimulation remain unclear. We postulated that FOXC2 regulates its own expression in sepsis, and its transcriptional autoregulation directs lymphatic EC cell-fate decision. Bioinformatic analysis identified potential FOXC2 binding sites in the FOXC2 promoter. In human lung EC, we verified using chromatin immunoprecipitation (ChIP) and luciferase assays that FOXC2 bound to its own promoter and stimulated its expression after LPS stimulation. Chemical inhibition of histone acetylation by garcinol repressed LPS-induced histone acetylation in the FOXC2 promoter region, and disrupted LPS-mediated FOXC2 binding and transcriptional activation. CRISPR/dCas9/gRNA directed against FOXC2-binding-element (FBE) suppressed LPS-stimulated FOXC2 binding and autoregulation by blocking FBEs in the FOXC2 promoter, and repressed expression of lymphatic EC markers. In a neonatal mouse model of sterile sepsis, LPS-induced FOXC2 binding to FBE and FOXC2 expression in lung EC was attenuated with garcinol treatment. These data reveal a new mechanism of LPS-induced histone acetylation-dependent FOXC2 autoregulation.

MicroRNAs and angiogenesis: a new era for the management of colorectal cancer

MicroRNAs (miRNAs) are a class of small noncoding RNA molecules containing only 20–22 nucleotides. MiRNAs play a role in gene silencing and translation suppression by targeting and binding to mRNA. Proper control of miRNA expression is very important for maintaining a normal physiological environment because miRNAs can affect most cellular pathways, including cell cycle checkpoint, cell proliferation, and apoptosis pathways, and have a wide range of target genes. With these properties, miRNAs can modulate multiple signalling pathways involved in cancer development, such as cell proliferation, apoptosis, and migration pathways. MiRNAs that activate or inhibit the molecular pathway related to tumour angiogenesis are common topics of research. Angiogenesis promotes tumorigenesis and metastasis by providing oxygen and diffusible nutrients and releasing proangiogenic factors and is one of the hallmarks of tumour progression. CRC is one of the most common tumours, and metastasis has always been a difficult issue in its treatment. Although comprehensive treatments, such as surgery, radiotherapy, chemotherapy, and targeted therapy, have prolonged the survival of CRC patients, the overall response is not optimistic. Therefore, there is an urgent need to find new therapeutic targets to improve CRC treatment. In a series of recent reports, miRNAs have been shown to bidirectionally regulate angiogenesis in colorectal cancer. Many miRNAs can directly act on VEGF or inhibit angiogenesis through other pathways (HIF-1a, PI3K/AKT, etc.), while some miRNAs, specifically many exosomal miRNAs, are capable of promoting CRC angiogenesis. Understanding the mechanism of action of miRNAs in angiogenesis is of great significance for finding new targets for the treatment of tumour angiogenesis. Deciphering the exact role of specific miRNAs in angiogenesis is a challenge due to the high complexity of their actions. Here, we describe the latest advances in the understanding of miRNAs and their corresponding targets that play a role in CRC angiogenesis and discuss possible miRNA-based therapeutic strategies.

Molecular features and gene expression signature of metastatic colorectal cancer (Review)

Uncontrollable metastatic outgrowth process is the leading cause of mortality worldwide, even in the case of colorectal cancer. Colorectal cancer (CRC) accounts for approximately 10% of all annually diagnosed cancers and 50% of CRC patients will develop metastases in the course of disease. Most patients with metastatic CRC have incurable disease. Even if patients undergo resection of liver metastases, the 5‑year survival rate ranges from 25 to 58%. Next‑generation sequencing of tumour specimens from large colorectal cancer patient cohorts has led to major advances in elucidating the genomic landscape of these tumours and paired metastases. The expression profiles of primary CRC and their metastatic lesions at both the gene and pathway levels were compared and led to the selection of early driver genes responsible for carcinogenesis and metastasis‑specific genes that increased the metastatic process. The genetic, transcriptional and epigenetic alteration encoded by these genes and their combination influence many pivotal signalling pathways, enabling the dissemination and outgrowth in distant organs. Therapeutic regimens affecting several different active pathways may have important implications for therapeutic efficacy.

The prognostic significance of FOXC2 gene expression in cancer: A comprehensive analysis of RNA-seq data from the cancer genome atlas

The FOXC2 transcription factor is a key regulator of tumor progression in many cancer types. Known to exhibit an array of oncogenic functions when dysregulated, FOXC2 has emerged as a useful biomarker for predicting disease aggression and patient outcome. In this regard, increased expression and nuclear localization of FOXC2 protein in tumor tissue have become well-established as poor prognostic factors for many cancer types. However, whether FOXC2 gene expression can serve as a similarly useful RNA-level biomarker has remained largely unexplored. Therefore, we conducted a comprehensive analysis of TCGA RNA-seq data to evaluate whether FOXC2 gene expression levels in primary tumor biopsies correlate with patient outcome. We report herein that increased expression of FOXC2 RNA in tumor tissue is a poor prognostic factor for patient survival in many cancer types. Moreover, we also found that FOXC2 gene expression predicts cancer patient response to several commonly prescribed chemotherapeutics. Together, these data highlight FOXC2 RNA expression in tumor tissue as an important biomarker with prognostic significance for solid tumors of diverse origin.

Advances in Modeling the Immune Microenvironment of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and second leading cause of cancer-related death in the US. CRC frequently metastasizes to the liver and these patients have a particularly poor prognosis. The infiltration of immune cells into CRC tumors and liver metastases accurately predicts disease progression and patient survival. Despite the evident influence of immune cells in the CRC tumor microenvironment (TME), efforts to identify immunotherapies for CRC patients have been limited. Here, we argue that preclinical model systems that recapitulate key features of the tumor microenvironment-including tumor, stromal, and immune cells; the extracellular matrix; and the vasculature-are crucial for studies of immunity in the CRC TME and the utility of immunotherapies for CRC patients. We briefly review the discoveries, advantages, and disadvantages of current in vitro and in vivo model systems, including 2D cell culture models, 3D culture systems, murine models, and organ-on-a-chip technologies.

CCMAlnc Promotes the Malignance of Colorectal Cancer by Modulating the Interaction Between miR-5001-5p and Its Target mRNA

Objective

Colorectal cancer (CRC) is highly malignant and cancer metastasis remains the predominant cause of CRC death. The potential molecular mechanism of long non-coding RNA (lncRNAs) in CRC malignance is still poorly elucidated.

Methods

CCMAlnc expression was analyzed by using the Sequence ReadArchive (SRA) database. Target gene expression was examined by real-time PCR and Western blotting. The biological function of CCMAlnc and miR-5001-5p was detected by cell invasion, CCK8 proliferation, and colony formation assays in loss of function and gain of function experiments in vitro. A luciferase assay was performed to validate the target site of miR-5001-5p on the 3′-UTR of HES6 mRNA.

Results

CCMAlnc was identified as a novel functional lncRNA in CRC. Elevated CCMAlnc was detected in CRC cells as well as in clinical CRC tissue samples, and the expression of this lncRNA positively correlated with the poor prognosis of CRC patients. Functional validation assays revealed that downregulation of CCMAlnc impaired CRC cell proliferation and invasion in vitro, but upregulation of CCMAlnc reversed this effect. Moreover, CCMAlnc was validated to act as a competing endogenous RNA (ceRNA) that stabilizes the expression of HES6 by downregulating miR-5001-5p.

Conclusion

CCMAlnc/miR-5001-5p/HES6 signaling is strongly activated to promote CRC malignance. CCMAlnc is defined as a potential candidate biomarker for metastasis prediction in CRC patients and as a potential therapeutic target for CRC treatment.

Hepatocyte growth factor/MET and CD44 in colorectal cancer: partners in tumorigenesis and therapy resistance

Intestinal epithelial self-renewal is a tightly controlled process, which is critically dependent on WNT signalling. Aberrant activation of the WNT pathway in intestinal stem cells (ISCs) results in constitutive transcription of target genes, which collectively drive malignant transformation in colorectal cancer (CRC). However, the contribution of individual genes to intestinal homeostasis and tumorigenesis often is incompletely defined. Here, we discuss converging evidence indicating that the receptor tyrosine kinase (RTK) MET and its ligand hepatocyte growth factor (HGF) play a major role in the intestinal damage response, as well as in intestinal tumorigenesis, by controlling the proliferation, survival, motility, and stemness of normal and neoplastic intestinal epithelial cells. These activities of MET are promoted by specific CD44 isoforms expressed by ISCs. The accrued data indicate that MET and the EGFR have overlapping roles in the biology of intestinal epithelium and that metastatic CRCs can exploit this redundancy to escape from EGFR-targeted treatments, co-opting HGF/MET/CD44v signalling. Hence, targeting both pathways may be required for effective treatment of (a subset of) CRCs. The RTK identity of MET, the distinctive 'plasminogen-like' structure and activation mode of its ligand HGF, and the specific collaboration of MET with CD44, provide several unique targeting options, which merit further exploration.

FOXO transcription factor family in cancer and metastasis

Forkhead box O (FOXO) transcription factors regulate diverse biological processes, affecting development, metabolism, stem cell maintenance and longevity. They have also been increasingly recognised as tumour suppressors through their ability to regulate genes essential for cell proliferation, cell death, senescence, angiogenesis, cell migration and metastasis. Mechanistically, FOXO proteins serve as key connection points to allow diverse proliferative, nutrient and stress signals to converge and integrate with distinct gene networks to control cell fate, metabolism and cancer development. In consequence, deregulation of FOXO expression and function can promote genetic disorders, metabolic diseases, deregulated ageing and cancer. Metastasis is the process by which cancer cells spread from the primary tumour often via the bloodstream or the lymphatic system and is the major cause of cancer death. The regulation and deregulation of FOXO transcription factors occur predominantly at the post-transcriptional and post-translational levels mediated by regulatory non-coding RNAs, their interactions with other protein partners and co-factors and a combination of post-translational modifications (PTMs), including phosphorylation, acetylation, methylation and ubiquitination. This review discusses the role and regulation of FOXO proteins in tumour initiation and progression, with a particular emphasis on cancer metastasis. An understanding of how signalling networks integrate with the FOXO transcription factors to modulate their developmental, metabolic and tumour-suppressive functions in normal tissues and in cancer will offer a new perspective on tumorigenesis and metastasis, and open up therapeutic opportunities for malignant diseases.

CREB5 promotes invasiveness and metastasis in colorectal cancer by directly activating MET

BACKGROUND

cAMP responsive element binding protein 5 (CREB5) is a transcriptional activator in eukaryotic cells that can regulate gene expression. Previously, we found that CREB5 was involved in the occurrence and development of colorectal cancer (CRC) using bioinformatics analysis. However, the biological roles and underlying regulatory mechanism of CREB5 in CRC remain unclear.

METHODS

Real-time PCR, western blotting, and immunohistochemistry were used to examine CREB5 expression. In vitro experiments including migration assay, wound-healing assay, chicken chorioallantoic membrane assay, and human umbilical vein endothelial cells tube formation assay were used to investigate the effects of CREB5 on CRC cell migration and tumor angiogenesis ability. Additionally, an orthotopic implantation assay was performed in nude mice to confirm the effects of CREB5 in vivo. Furthermore, gene set enrichment analysis was performed to explore the potential mechanism of CREB5 in CRC.

RESULTS

We found that CREB5 expression was highly upregulated in CRC. CREB5 overexpression was positively correlated with advanced WHO stages and TNM stages and shorter survival in CRC patients. Moreover, CREB5 overexpression promoted while CREB5 silencing reduced the invasiveness and metastatic capacity of CRC cells both in vitro and in vivo. Furthermore, CREB5 directly interacted with the MET promoter and activated the hepatocyte growth factor-MET signalling pathway. Importantly, inhibition of MET reduced the invasion and metastasis of CREB5-overexpressing CRC cells, suggesting that CREB5 promotes metastasis mainly through activation of MET signalling.

CONCLUSION

Our study demonstrates a crucial role for CREB5 in CRC metastasis by directly upregulating MET expression. CREB5 may be both a potential prognostic marker and a therapeutic target to effectively overcome metastasis in CRC.

FOXC2 Disease Mutations Identified in Lymphedema Distichiasis Patients Impair Transcriptional Activity and Cell Proliferation

FOXC2 is a member of the human forkhead-box gene family and encodes a regulatory transcription factor. Mutations in FOXC2 have been associated with lymphedema distichiasis (LD), an autosomal dominant disorder that primarily affects the limbs. Most patients also show extra eyelashes, a condition known as distichiasis. We previously reported genetic and clinical findings in six unrelated families with LD. Half the patients showed missense mutations, two carried frameshift mutations and a stop mutation was identified in a last patient. Here we analyzed the subcellular localization and transactivation activity of the mutant proteins, showing that all but one (p.Y109*) localized to the nucleus. A significant reduction of transactivation activity was observed in four mutants (p.L80F, p.H199Pfs*264, p.I213Tfs*18, p.Y109*) compared with wild type FOXC2 protein, while only a partial loss of function was associated with p.V228M. The mutant p.I213V showed a very slight increase of transactivation activity. Finally, immunofluorescence analysis revealed that some mutants were sequestered into nuclear aggregates and caused a reduction of cell viability. This study offers new insights into the effect of FOXC2 mutations on protein function and shows the involvement of aberrant aggregation of FOXC2 proteins in cell death.

LncRNA FOXC2-AS1 enhances FOXC2 mRNA stability to promote colorectal cancer progression via activation of Ca2+-FAK signal pathway

Long noncoding RNAs (lncRNAs) have been confirmed, which are involved in tumorigenesis and metastasis in colorectal cancer (CRC). FOXC2 antisense RNA 1 (FOXC2-AS1) was reported, facilitating the proliferation and progression in several cancers. However, the role of FOXC2-AS1 in CRC cell migration and metastasis is not unclear. In this study, we observed that lncRNA FOXC2-AS1 was upregulated in CRC tissues, and its high expression indicated the poor survival in CRC patients. Meanwhile, FOXC2-AS1 was higher in CRC tissues with metastasis than that of nonmetastatic tumor tissues. We found that FOXC2-AS1 was predominately expressed in the nucleus of tissues and cells. FOXC2-AS1 knockdown suppressed CRC cell growth, invasion, and metastasis in vitro and in vivo. Moreover, FOXC2-AS1 could positively regulate the neighboring gene FOXC2 and stabilized FOXC2 mRNA by forming a RNA duplex. Meanwhile, ectopic expression of FOXC2 could obviously alleviate the suppressed effects caused by silencing FOXC2-AS1. For the mechanism, FOXC2-AS1 knockdown could reduce intracellular Ca²⁺ levels, inhibited FA formation and FAK signaling, and these suppressed effects were mitigated by increasing FOXC2 expression. These results demonstrated that FOXC2-AS1 enhances FOXC2 mRNA stability to promote CRC proliferation, migration, and invasion by activation of Ca²⁺-FAK signaling, which implicates that FOXC2-AS1 may represent a latent effective therapeutic target for CRC progression.

ERα-related chromothripsis enhances concordant gene transcription on chromosome 17q11.1-q24.1 in luminal breast cancer

BACKGROUND

Chromothripsis is an event of genomic instability leading to complex chromosomal alterations in cancer. Frequent long-range chromatin interactions between transcription factors (TFs) and targets may promote extensive translocations and copy-number alterations in proximal contact regions through inappropriate DNA stitching. Although studies have proposed models to explain the initiation of chromothripsis, few discussed how TFs influence this process for tumor progression.

METHODS

This study focused on genomic alterations in amplification associated regions within chromosome 17. Inter-/intra-chromosomal rearrangements were analyzed using whole genome sequencing data of breast tumors in the Cancer Genome Atlas (TCGA) cohort. Common ERα binding sites were defined based on MCF-7, T47D, and MDA-MB-134 breast cancer cell lines using univariate K-means clustering methods. Nanopore sequencing technology was applied to validate frequent rearrangements detected between ATC loci on 17q23 and an ERα hub on 20q13. The efficacy of pharmacological inhibition of a potentially druggable target gene on 17q23 was evaluated using breast cancer cell lines and patient-derived circulating breast tumor cells.

RESULTS

There are five adjoining regions from 17q11.1 to 17q24.1 being hotspots of chromothripsis. Inter-/intra-chromosomal rearrangements of these regions occurred more frequently in ERα-positive tumors than in ERα-negative tumors. In addition, the locations of the rearrangements were often mapped within or close to dense ERα binding sites localized on these five 17q regions or other chromosomes. This chromothriptic event was linked to concordant upregulation of 96 loci that predominantly regulate cell-cycle machineries in advanced luminal tumors. Genome-editing analysis confirmed that an ERα hub localized on 20q13 coordinately regulates a subset of these loci localized on 17q23 through long-range chromosome interactions. One of these loci, Tousled Like Kinase 2 (TLK2) known to participate in DNA damage checkpoint control, is an actionable target using phenothiazine antipsychotics (PTZs). The antiproliferative effect of PTZs was prominent in high TLK2-expressing cells, compared to low expressing cells.

CONCLUSION

This study demonstrates a new approach for identifying tumorigenic drivers from genomic regions highly susceptible to ERα-related chromothripsis. We found a group of luminal breast tumors displaying 17q-related chromothripsis for which antipsychotics can be repurposed as treatment adjuncts.

Decreased ZNF750 promotes angiogenesis in a paracrine manner via activating DANCR/miR-4707-3p/FOXC2 axis in esophageal squamous cell carcinoma

ZNF750 is one novel significantly mutated gene identified in esophageal squamous cell carcinoma (ESCC) using next-generation sequencing. However, its clinically relevant and potential mechanisms have remained elusive. Using genomic sequencing of 612 ESCC patients, we analyzed the associations of ZNF750 mutations with clinicopathologic features and its prognostic value. We further investigated the function and underlying mechanism of ZNF750 in angiogenesis. The results showed ZNF750 mutations/deletions are significantly associated with malignant progression and poor prognosis of ESCC patients. Decreased ZNF750 in ESCC cells induces enhanced angiogenesis of human umbilical vein endothelial cells (HUVECs) and human arterial endothelial cells (HAECs), and the effect may be indirectly mediated by FOXC2. RNA-seq and ChIP shows lncRNA DANCR is a direct downstream target of ZNF750. Furtherly, knockdown ZNF750 evokes DANCR expression, which prevents miR-4707-3p to interact with FOXC2 as a microRNA sponge in a ceRNA manner, leading to enhanced FOXC2 signaling and angiogenesis. In contrast, ZNF750 expression reverses the effect. Our study reveals a novel mechanism of ZNF750, highlights a significance of ZNF750 as a metastatic and prognostic biomarker, and offers potential therapeutic targets for ESCC patients harboring ZNF750 mutations.

The CCDC43-ADRM1 axis regulated by YY1, promotes proliferation and metastasis of gastric cancer

Previous studies have shown an association between coiled-coil domain-containing (CCDC) genes and different cancers. Our previous studies revealed that CCDC43 is highly expressed in colorectal cancer, but the expression and molecular mechanisms of CCDC43 in gastric cancer (GC) are yet to be determined. Here, we show that CCDC43 is overexpressed in gastric tissues. CCDC43 expression is closely related to tumor differentiation, lymph-node-metastasis, and prognosis of gastric cancer. Overexpression of CCDC43 promotes the proliferation, invasion, and metastasis of GC cells. CCDC43 may upregulate and stabilize ADRM1, resulting in the construction of the ubiquitin-mediated proteasome. In contrast, inhibition of ADRM1 could reverse the function of CCDC43 in GC both in vitro and in vivo. Our data demonstrate that transcription factor YY1 directly binds to CCDC43 and ADRM1 gene promoters, leading to over-expression of CCDC43 and ADRM1. Furthermore, in vitro experiments demonstrate that knock down of CCDC43 or ADRM1 attenuates the YY1-mediated malignant phenotypes. Finally, the association among YY1, CCDC43 and ADRM1 is validated in clinical samples. Our findings suggest that the CCDC43-ADRM1 axis regulated by YY1, promotes proliferation and metastasis of GC, and the axis may be a potential therapeutic target for GC.

miR-34c Targets MET to Improve the Anti-Tumor Effect of Cisplatin on Ovarian Cancer

Background

Cisplatin is a commonly used drug for the treatment of various types of malignant cancers, including ovarian cancer. However, resistance to cisplatin is still a considerable obstacle to achieve a satisfactory therapeutic effect. The purpose of this study is to develop a strategy to sensitize ovarian cancer cells to cisplatin-induced cytotoxicity.

Methods

miR-34c levels in ovarian cancer tissues and cell lines were tested by qRT-PCR analysis. In vitro assays, the effect of miR-34c on cisplatin was evaluated by using MTT. Expression of MET and phosphorylation of PI3K and AKT were tested by Western blot assays. Conjugation with Bad and Bcl-xl was evaluated through immunoprecipitation. Flow cytometry analysis was performed to measure the apoptotic rate of ovarian cancer cells.

Results

Downregulation of miR-34c was observed in ovarian cancer tissues and cell lines. However, miR-34c overexpression was found to sensitize ovarian cancer cells to cisplatin treatment in vitro and in vivo. Mechanically, we found that miR-34c targeted the MET gene, thereby inhibiting the phosphorylation of PI3K and AKT to activate Bad. As a result, miR-34c reduced resistance of ovarian cancer cells to cisplatin-induced apoptosis.

Conclusion

miR-34c/MET axis promotes cisplatin-induced cytotoxicity against ovarian cancer by targeting the MET/PI3K/AKT/Bad pathway.

Circular RNA PVT1 promotes metastasis via regulating of miR-526b/FOXC2 signals in OS cells

As a class of covalently closed non-coding RNAs, circular RNAs (circRNAs) are key regulators in various malignancies including osteosarcoma (OS). In the present study, we found that circular RNA PVT1 (circPVT1) was up-regulated in OS and correlated with poor prognosis of patients with OS. Functionally, we showed that knockdown of circPVT1 suppressed OS cells metastasis. In addition, we found that (forkhead box C2) FOXC2 was a downstream gene in circPVT1-mediated metastasis in OS cells. We demonstrated that circPVT1 promoted OS cells metastasis via post-transcriptionally regulating of FOXC2. Furthermore, we revealed that microRNA 526b (miR-526b) was a key bridge which connected circPVT1 and FOXC2. We showed that miR-526b was down-regulated in OS tissue and cell lines. Through a transwell assay, we found that miR-526b suppressed OS cells metastasis by targeting of FOXC2. We also showed that miR-526b targeted circPVT1 via similar mircoRNA response elements (MREs) as it did for FOXC2. Finally, we proved that circPVT1 decoyed miR-526b to promote FOXC2-mediated metastasis in OS cells. In brief, our current study demonstrated that circPVT1, functioning as an oncogene, promotes OS cells metastasis via regulation of FOXC2 by acting as a ceRNA of miR-526b. CircPVT1/miR-526b/FOXC2 axis might be a novel target in molecular treatment of OS.

The FOXC2 Transcription Factor Promotes Melanoma Outgrowth and Regulates Expression of Genes Associated With Drug Resistance and Interferon Responsiveness

BACKGROUND/AIM

The FOXC2 transcription factor promotes the progression of several cancer types, but has not been investigated in the context of melanoma cells. To study FOXC2's influence on melanoma progression, we generated a FOXC2-deficient murine melanoma cell line and evaluated The Cancer Genome Atlas (TCGA) patient datasets.

MATERIALS AND METHODS

We compared tumor growth kinetics and RNA-seq/qRT-PCR gene expression profiles from wild-type versus FOXC2-deficient murine melanomas. We also performed Kaplan-Meier survival analysis of TCGA data to assess the influence of FOXC2 gene expression on melanoma patients' response to chemotherapy and immunotherapy.

RESULTS

FOXC2 promotes melanoma progression and regulates the expression of genes associated with multiple oncogenic pathways, including the oxidative stress response, xenobiotic metabolism, and interferon responsiveness. FOXC2 expression in melanoma correlates negatively with patient response to chemotherapy and immunotherapy.

CONCLUSION

FOXC2 drives a tumor-promoting gene expression program in melanoma and is a prognostic indicator of patient response to multiple cancer therapies.

Hsa_circ_001680 affects the proliferation and migration of CRC and mediates its chemoresistance by regulating BMI1 through miR-340

BACKGROUND

Accumulating evidence indicates that circular RNAs (circRNAs) act as microRNA (miRNA) sponges to directly inhibit specific miRNAs and alter their ability to regulate gene expression at the post-transcriptional level; this mechanism is believed to occur in various cancers. However, the expression level, precise function and mechanism of circ_001680 in colorectal carcinoma (CRC) are largely unknown.

METHODS

qRT-PCR was used to detect the expression of circ_001680 and miR-340 in human CRC tissues and their matched normal tissues. Bioinformatics analyses and dual-fluorescence reporter assays were used to evaluate whether circ_001680 could bind to miR-340. Circ_001680 overexpression and knockdown cell lines were constructed to investigate the proliferation and migration abilities in vivo and in vitro through function-based experiments, including CCK8, plate clone formation, transwell, and wounding healing assays. The relationships among circ_001680, miR-340 and BMI1 were investigated by bioinformatics analyses, dual-fluorescence reporter system, FISH, RIP and RNA pull down assays. Sphere forming assays and flow cytometry analyses were used to assess the effect of circ_001680 on the stemness characteristics of CRC cells.

RESULTS

Circ_001680 was more highly expressed in of CRC tissue than in matched adjacent normal tissues from the same patients. Circ_001680 was observed to enhance the proliferation and migration capacity of CRC cells. Furthermore, dual-fluorescence reporter assays confirmed that circ_001680 affects the expression of BMI1 by targeting miR-340. More importantly, we also found that circ_001680 could promote the cancer stem cell (CSC) population in CRC and induce irinotecan therapeutic resistance by regulating the miR-340 target gene BMI1.

CONCLUSIONS

Our results demonstrated that circ_001680 is a part of a novel strategy to induce chemotherapy resistance in CRC through BMI1 upregulation. Moreover, circ_001680 may be a promising diagnostic and prognostic marker to determine the success of irinotecan-based chemotherapy.

Sec62 promotes early recurrence of hepatocellular carcinoma through activating integrinα/CAV1 signalling

Postsurgical recurrence within 2 years is the major cause of poor survival of hepatocellular carcinoma (HCC) patients. However, the molecular mechanism underlying HCC recurrence remains unclear. Here, we distinguish the function and mechanism of Sec62 in promoting HCC recurrence. The correlation between Sec62 and early recurrence was demonstrated in 60 HCC samples from a prospective study. HCC cells with Sec62 knockdown (Sec62^KD) or overexpression (Sec62^OE) were used to determine the potential of Sec62 in cell migration in vitro. Microarray analysis comparing Sec62^KD or Sec62^OE to their control counterparts was used to explore the mechanisms of Sec62-induced recurrence. A luciferase-labelled orthotopic nude mouse model of HCC with Sec62^KD or Sec62^OE was used to validate the potential of Sec62 in early HCC recurrence in vivo. We found that high expression of Sec62 was positively correlated with surgical recurrence in clinical HCC samples. Multivariate analysis revealed that Sec62 was an independent prognostic factor for early recurrence in postoperative HCC patients. Moreover, Sec62 promoted migration and invasion of HCC cells in vitro and postsurgical recurrence in vivo. Mechanically, integrinα/CAV1 signalling was identified as one of the targets of Sec62 in cell movement. Overexpression of integrin α partially rescued the Sec62 knockdown-induced inhibition of cell migration. Sec62 is a potentially prognostic factor for early recurrence in postoperative HCC patients and promotes HCC metastasis through integrinα/CAV1 signalling. Sec62 might be an attractive drug target for combating HCC postsurgical recurrence.

Preclinical evaluation of an unconventional ruthenium-gold-based chemotherapeutic: RANCE-1, in clear cell renal cell carcinoma

BACKGROUND

There are few effective treatments for patients with advanced clear cell renal cell carcinoma (CCRCC). Recent findings indicate that ruthenium-gold containing compounds exhibit significant antitumor efficacy against CCRCC in vitro affecting cell viability as well as angiogenesis and markers driving those 2 phenomena. However, no in vivo preclinical evaluation of this class of compounds has been reported.

METHODS

Following the dose-finding pharmacokinetic determination, NOD.CB17-Prkdc SCID/J mice bearing xenograft CCRCC Caki-1 tumors were treated in an intervention trial for 21 days at 10 mg/kg/72h of RANCE-1. At the end of the trial, tumor samples were analyzed for histopathological and changes in protein expression levels were assessed.

RESULTS

After 21 days of treatment there was no significant change in tumor size in the RANCE-1-treated mice as compared to the starting size (+3.87%) (P = 0.082) while the vehicle treated mice exhibited a significant tumor size increase (+138%) (P < 0.01). There were no signs of pathological complications as a result of treatment. Significant reduction in the expression of VEGF, PDGF, FGF, EGFR, and HGRF, all key to the proliferation of tumor cells and stromal cells serving protumorigenic purposes was observed.

CONCLUSIONS

The tumor growth inhibition displayed and favorable pathology profile of RANCE-1 makes it a promising candidate for further evaluation toward clinical use for the treatment of advanced CCRCC.

Hydroxychavicol from Piper betle induces apoptosis, cell cycle arrest, and inhibits epithelial-mesenchymal transition in pancreatic cancer cells

Pancreatic cancer is a major cause of cancer-related mortality around the world. Currently, options for diagnosis and treatment are extremely limited, which culminates in a very high mortality rate. Intensive research spanning more than four decades has met several roadblocks in terms of improvement in overall survival. In this study, we have evaluated the effect of Hydroxychavicol (HC), a naturally occurring and abundantly isolatable allylarene from Piper betle leaves on pancreatic cancer cells. Our investigation reveals that HC inhibits proliferation and epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. HC induces DNA damage, as evidenced by γ-H2AX, 53BP1 induction and comet assay, which further results in mitotic catastrophe and apoptosis. The apoptosis induced by HC is JNK pathway-dependent and caspase-mediated. HC also inhibits migration and invasion of pancreatic cancer cells via a generalized repression of genes involved in EMT. A quantitative real time PCR-based array revealed at least 14 different genes to be differentially expressed upon HC treatment in pancreatic cancer cells. These results show significant potential of HC as an anticancer agent against pancreatic cancer.

UBN2 promotes tumor progression via the Ras/MAPK pathway and predicts poor prognosis in colorectal cancer

Background

Ubinuclein-2 (UBN2) is a nuclear protein that interacts with many transcription factors. The molecular role and mechanism of UBN2 in the development and progression of cancers, including colorectal cancer (CRC), is not well understood. The current study explored the role of UBN2 in the development and progression CRC.

Methods

Oncomine network and The Cancer Genome Atlas (TCGA) database were downloaded and Gene Set Enrichment Analysis (GSEA) was performed to compare the UBN2′s expression between normal and tumor tissues, as well as the potential correlation of UBN2 expression with signaling pathways. Immunohistochemistry (IHC), qRT-PCR and Western blotting were performed to determine the expression of UBN2 in CRC tissues or cell lines. In vitro proliferation and invasion assays, and orthotopic mouse metastatic model were used to analyze the effect of UBN2 on the development and progression of CRC.

Results

The analysis of UBN2 expression using Oncomine network showed that UBN2 was upregulated in CRC tissues compared to matched adjacent normal intestinal epithelial tissues. IHC, qRT-PCR and Western blotting confirmed that UBN2 expression is higher in CRC tissues compared with matched adjacent normal intestinal epithelial tissues. In addition, analyses of TCGA data revealed that high UBN2 expression was associated with advanced stages of lymph node metastasis, distant metastasis, and short survival time in CRC patients. IHC showed that high UBN2 expression is correlated with advanced stages of CRC. Moreover, UBN2 is highly expressed in the liver metastatic lesions. Furthermore, knockdown of UBN2 inhibited the growth, invasiveness and metastasis of CRC cells via regulation of the Ras/MAPK signaling pathway.

Conclusion

The current study demonstrates that UBN2 promotes tumor progression in CRC. UBN2 may be used as a promising biomarker for predicting the prognosis of CRC patients.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0848-4) contains supplementary material, which is available to authorized users.

AKIP1 promotes early recurrence of hepatocellular carcinoma through activating the Wnt/β-catenin/CBP signaling pathway

The early recurrence of hepatocellular carcinoma (HCC) is the main obstacle for long-term survival of patients. Wnt/β-catenin signaling has been involved in the development and progression of HCC. However, the molecular changes that link Wnt/β-catenin activation and HCC early recurrence remain poorly understood. Here we identified AKIP1 as a binding partner of β-catenin. AKIP1 interacted with and sustained β-catenin in the nuclear by blocking its interaction with adenomatous polyposis coli protein (APC). Moreover, AKIP1 enhanced the protein kinase A catalytic subunit (PKAc)-mediated phosphorylation of β-catenin, leading to recruitment of cyclic AMP response element-binding protein (CBP) and activation of β-catenin downstream transcription. Increased AKIP1 expression was observed in HCC clinical samples and correlated with early recurrence and poor prognosis of HCC. AKIP1 promoted invasion and colony outgrowth in vitro and increased intrahepatic and lung metastasis in vivo. Treatment with a CBP inhibitor ICG-001 effectively inhibited the metastatic progression of HCC tumors that had elevated AKIP1 in both cell line and patient-derived xenograft mouse models. Our findings not only establish AKIP1 as a novel regulator of Wnt/β-catenin signaling as well as HCC early recurrence but also highlight targeting the AKIP1/β-catenin/CBP axis as attractive therapies for combating HCC metastatic relapse.

miR-622 inhibits angiogenesis by suppressing the CXCR4-VEGFA axis in colorectal cancer

Angiogenesis is essential for tumor metastasis. Our previous study has revealed that miR-622 inhibits colorectal cancer (CRC) metastasis. Here, we aimed to explore the effects and potential molecular mechanisms of action of miR-622 on angiogenesis. We found that overexpression of miR-622 inhibited CRC angiogenesis in vitro, according to suppression of proliferation, migration, tube formation, and invasiveness of human umbilical vein endothelial cells (HUVECs) treated with a tumor cell-conditioned medium derived from Caco-2 or HT-29 cells. Likewise, enhanced miR-622 expression suppressed CRC angiogenesis in vivo as determined by the measurement of Ki67 and VEGFA levels and microvessel density (by immunostaining). CXCR4, encoding a positive regulator of vascular endothelial growth factor A (VEGFA), was shown to be a direct target of miR-622. Overexpression of CXCR4 attenuated the inhibition of VEGFA expression by miR-622 and reversed the loss of tumor angiogenesis caused by miR-622. Taken together, these data show that miR-622 inhibits CRC angiogenesis by suppressing the CXCR4-VEGFA signaling axis, which represents a promising target for developing a new therapeutic strategy against CRC.

A genome-wide association study identifies single nucleotide polymorphisms associated with time-to-metastasis in colorectal cancer

Background

Differentiating between cancer patients who will experience metastasis within a short time and who will be long-term survivors without metastasis is a critical aim in healthcare. The microsatellite instability (MSI)-high tumor phenotype is such a differentiator in colorectal cancer, as patients with these tumors are unlikely to experience metastasis. Our aim in this study was to determine if germline genetic variations could further differentiate colorectal cancer patients based on the long-term risk and timing of metastasis.

Methods

The patient cohort consisted of 379 stage I-III Caucasian colorectal cancer patients with microsatellite stable or MSI-low tumors. We performed univariable analysis on 810,622 common single nucleotide polymorphisms (SNPs) under different genetic models. Depending on the long-term metastasis-free survival probability estimates, we applied a mixture cure model, Cox proportional hazards regression model, or log-rank test. For SNPs reaching Bonferroni-corrected significance (p < 6.2 × 10^− 8) having valid genetic models, multivariable analysis adjusting for significant baseline characteristics was conducted.

Results

After adjusting for significant baseline characteristics, specific genotypes of ten polymorphisms were significantly associated with time-to-metastasis. These polymorphisms are three intergenic SNPs, rs5749032 (p = 1.28 × 10^− 10), rs2327990 (p = 9.59 × 10^− 10), rs1145724 (p = 3 × 10^− 8), and seven SNPs within the non-coding sequences of three genes: FHIT (p = 2.59 × 10^− 9), EPHB1 (p = 8.23 × 10^− 9), and MIR7515 (p = 4.87 × 10^− 8).

Conclusions

Our results suggest novel associations of specific genotypes of SNPs with early metastasis in Caucasian colorectal cancer patients. These associations, once replicated in other patient cohorts, could assist in the development of personalized treatment strategies for colorectal cancer patients.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5346-5) contains supplementary material, which is available to authorized users.

The forkhead-box family of transcription factors: key molecular players in colorectal cancer pathogenesis

Colorectal cancer (CRC) is the third most commonly occurring cancer worldwide and the fourth most frequent cause of death having an oncological origin. It has been found that transcription factors (TF) dysregulation, leading to the significant expression modifications of genes, is a widely distributed phenomenon regarding human malignant neoplasias. These changes are key determinants regarding tumour’s behaviour as they contribute to cell differentiation/proliferation, migration and metastasis, as well as resistance to chemotherapeutic agents. The forkhead box (FOX) transcription factor family consists of an evolutionarily conserved group of transcriptional regulators engaged in numerous functions during development and adult life. Their dysfunction has been associated with human diseases. Several FOX gene subgroup transcriptional disturbances, affecting numerous complex molecular cascades, have been linked to a wide range of cancer types highlighting their potential usefulness as molecular biomarkers. At least 14 FOX subgroups have been related to CRC pathogenesis, thereby underlining their role for diagnosis, prognosis and treatment purposes.

This manuscript aims to provide, for the first time, a comprehensive review of FOX genes’ roles during CRC pathogenesis. The molecular and functional characteristics of most relevant FOX molecules (FOXO, FOXM1, FOXP3) have been described within the context of CRC biology, including their usefulness regarding diagnosis and prognosis. Potential CRC therapeutics (including genome-editing approaches) involving FOX regulation have also been included. Taken together, the information provided here should enable a better understanding of FOX genes’ function in CRC pathogenesis for basic science researchers and clinicians.

Genomic and regulatory characteristics of significant transcription factors in colorectal cancer metastasis

The dysregulation of transcription factors has an important impact on the oncogenesis and tumor progression. Nonetheless, its functions in colorectal cancer metastasis are still unclear. In this study, four transcription factors (HNF4A, HSF1, MECP2 and RAD21) were demonstrated to be associated with the metastasis of colorectal cancer in both RNA and protein levels. To comprehensively explore the intrinsic mechanisms, we profiled the molecular landscape of these metastasis-related transcription factors from multiple perspectives. In particular, as the crucial factors affecting genome stability, both copy number variation and DNA methylation exerted their strengths on the expression of these transcription factors (except MECP2). Additionally, based on a series of bioinformatics analyses, putative long non-coding RNAs were identified as functional regulators. Besides that, rely on the ATAC-Seq and ChIP-Seq profiles, we detected the target genes regulated by each transcription factor in the active chromatin zones. Finally, we inferred the associations between the target genes by Bayesian networks and identified LMO7 and ARL8A as potential clinical biomarkers. Taken together, our research systematically characterized the regulatory cascades of HNF4A, HSF1, MECP2 and RAD21 in colorectal cancer metastasis.

Hypermethylation of DMTN promotes the metastasis of colorectal cancer cells by regulating the actin cytoskeleton through Rac1 signaling activation

Background

Colorectal cancer (CRC) is one of the most common digestive malignant tumors, and DMTN is a transcriptionally differentially expressed gene that was identified using CRC mRNA sequencing data from The Cancer Genome Atlas (TCGA). Our preliminary work suggested that the expression of DMTN was downregulated in CRC, and the Rac1 signaling pathway was significantly enriched in CRC tissues with low DMTN expression. However, the specific functions and underlying molecular mechanisms of DMTN in the progression of CRC and the upstream factors regulating the downregulation of the gene remain unclear.

Methods

DMTN expression was analyzed in CRC tissues, and the relationship between DMTN expression and the clinicopathological parameters was analyzed. In vitro and in vivo experimental models were used to detect the effects of DMTN dysregulation on invasion and metastasis of CRC cells. GSEA assay was performed to explore the mechanism of DMTN in invasion and metastasis of CRC. Westernblot, Co-IP and GST-Pull-Down assay were used to detect the interaction between DMTN and ARHGEF2, as well as the activation of the RAC1 signaling. Bisulfite genomic sequence (BSP) assay was used to test the degree of methylation of DMTN gene promoter in CRC tissues.

Results

We found that the expression of DMTN was significantly decreased in CRC tissues, and the downregulation of DMTN was associated with advanced progression and poor survival and was regarded as an independent predictive factor of CRC patient prognosis. The overexpression of DMTN inhibited, while the knockdown of DMTN promoted, invasion and metastasis in CRC cells. Moreover, hypermethylation and the deletion of DMTN relieved binding to the ARHGEF2 protein, activated the Rac1 signaling pathway, regulated actin cytoskeletal rearrangements, and promoted the invasion and metastasis of CRC cells.

Conclusion

Our study demonstrated that the downregulation of DMTN promoted the metastasis of colorectal cancer cells by regulating the actin cytoskeleton through RAC1 signaling activation, potentially providing a new therapeutic target to enable cancer precision medicine for CRC patients.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0958-1) contains supplementary material, which is available to authorized users.

The Dominant Role of Forkhead Box Proteins in Cancer

Forkhead box (FOX) proteins are multifaceted transcription factors that are significantly implicated in cancer, with various critical roles in biological processes. Herein, we provide an overview of several key members of the FOXA, FOXC, FOXM1, FOXO and FOXP subfamilies. Important pathophysiological processes of FOX transcription factors at multiple levels in a context-dependent manner are discussed. We also specifically summarize some major aspects of FOX transcription factors in association with cancer research such as drug resistance, tumor growth, genomic alterations or drivers of initiation. Finally, we suggest that targeting FOX proteins may be a potential therapeutic strategy to combat cancer.

Keratin 80 promotes migration and invasion of colorectal carcinoma by interacting with PRKDC via activating the AKT pathway

Little is known about the function of Keratin 80 (KRT80), an epithelial keratin, in cancer. This study investigated the role of KRT80 in the prognosis of colorectal carcinoma (CRC) and the underlying mechanisms involved in CRC migration and invasion. We analyzed the expression of KRT80 using The Cancer Genome Atlas and Oncomine databases. Higher expression of KRT80 was found to be significantly associated with multiple pathological parameters, lower disease-free survival, and overall survival in CRC patients. Also, KRT80 was an independent prognostic indicator for CRC. Furthermore, altered KRT80 expression impacted migration and invasion of CRC cells, as well as the expression of epithelial–mesenchymal transition (EMT)-related markers and cell morphology via the AKT pathway. Inhibiting the expression of AKT could reverse these phenomena. Liquid Chromatograph Mass Spectrometer/Mass Spectromete, Co-immunoprecipitation, and laser scanning confocal microscopy techniques showed that KRT80 could interact with protein kinase, DNA-activated, catalytic polypeptide (PRKDC). Suppressing PRKDC could inhibit the expression of AKT and EMT, as well as the migration and invasion of CRC cells. Taken together, these results demonstrated that KRT80 was an independent prognostic biomarker for CRC and promoted CRC migration and invasion by interacting with PRKDC via activation of the AKT pathway.

MiR-452 promotes an aggressive colorectal cancer phenotype by regulating a Wnt/β-catenin positive feedback loop

Background

Aberrant activation of Wnt/β-catenin signaling pathway is considered to be an important issue in progression and metastasis of various human cancers, especially in colorectal cancer (CRC). MiR-452 could activate of Wnt/β-catenin signaling. But the mechanism remains unclear.

Methods

The expression of miR-452 in CRC and normal tissues was detected by real-time quantitative PCR. The effect of miR-452 on CRC growth and invasion was conducted by functional experiments in vitro and in vivo. Bioinformatics and cell luciferase function studies verified the direct regulation of miR-452 on the 3’-UTR of the GSK3β, which leads to the activation of Wnt/β-catenin signaling.

Results

MiR-452 was upregulated in CRC compared with normal tissues and was correlated with clinical significance. The luciferase reporter system studies affirmed the direct regulation of miR-452 on the 3’-UTR of the GSK3β, which activate the Wnt/β-catenin signaling. The ectopic upregulation of miR-452 significantly inhibited the expression of GSK3β and enhanced CRC proliferation and invasion in vitro and in vivo. Meanwhile, knockdown of miR-452 significantly recovered the expression of GSK3β and attenuated Wnt/β-catenin-mediated cell metastasis and proliferation. More important, T-cell factor/lymphoid enhancer factor (TCF/LEF) family of transcription factors, which are crucial downstream molecules of the Wnt/β-catenin signaling pathway was verified as a valid transcription factor of miR-452’s promoter.

Conclusions

Our findings first demonstrate that miR-452-GSK3β-LEF1/TCF4 positive feedback loop induce CRC proliferation and migration.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0879-z) contains supplementary material, which is available to authorized users.

A novel mechanism of plasminogen activation in epithelial and mesenchymal cells

Cancer dissemination is initiated by the movement of cells into the vasculature which has been reported to be triggered by EMT (epithelial to mesenchymal transition). Cellular dissemination also requires proteases that remodel the extracellular matrix. The protease, plasmin is a prominent player in matrix remodeling and invasion. Despite the contribution of both EMT and the plasminogen activation (PA) system to cell dissemination, these processes have never been functionally linked. We reveal that canonical Smad-dependent TGFβ1 signaling and FOXC2-mediated PI3K signaling in cells undergoing EMT reciprocally modulate plasminogen activation partly by regulating the plasminogen receptor, S100A10 and the plasminogen activation inhibitor, PAI-1. Plasminogen activation and plasminogen-dependent invasion were more prominent in epithelial-like cells and were partly dictated by the expression of S100A10 and PAI-1.

FOXF1 Induces Epithelial-Mesenchymal Transition in Colorectal Cancer Metastasis by Transcriptionally Activating SNAI1

Forkhead Box F1 (FOXF1) has been recently implicated in cancer progression and metastasis of lung cancer and breast cancer. However, the biological functions and underlying mechanisms of FOXF1 in the regulation of the progression of colorectal cancer (CRC) are largely unknown. We showed that FOXF1 was up-regulated in 93 paraffin-embedded archived human CRC tissue, and both high expression and nuclear location of FOXF1 were significantly associated with the aggressive characteristics and poorer survival of CRC patients. The GSEA analysis showed that the higher level of FOXF1 was positively associated with an enrichment of EMT gene signatures, and exogenous overexpression of FOXF1 induced EMT by transcriptionally activating SNAI1. Exogenous overexpression FOXF1 functionally promoted invasion and metastasis features of CRC cells, and inhibition of SNAI1 attenuates the invasive phenotype and metastatic potential of FOXF1-overexpressing CRC cells. Furthermore, the results of the tissue chip showed that the expression of FOXF1 was positively correlated with SNAI1 in CRC tissues chip. These results suggested that FOXF1 plays a critical role in CRC metastasis by inducing EMT via transcriptional activation of SNAI1, highlighting a potential new therapeutic strategy for CRC.

Hallmarks of Cancer-Related Newly Prognostic Factors of Oral Squamous Cell Carcinoma

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the sixth leading malignancy worldwide. OSCC is an aggressive tumor and its prognosis has exhibited little improvement in the last three decades. Comprehensive elucidation of OSCC's molecular mechanism is imperative for early detection and treatment, improving patient survival. Based on broadly accepted notions, OSCC arises from multiple genetic alterations caused by chronic exposure to carcinogens. In 2011, research revealed 10 key alterations fundamental to cancer cell development: sustaining proliferative signaling, evading growth suppressors, avoiding immune destruction, activating invasion and metastasis, tumor-promoting inflammation, enabling replicative immortality, inducing angiogenesis, genome instability and mutation, resisting cell death, and deregulating energetics. This review describes molecular pathological findings on conventional and novel hallmarks of OSCC prognostic factors. In addition, the review summarizes the functions and roles of several molecules as novel OSCC prognosticators.

High expression of forkhead box protein C2 is associated with aggressive phenotypes and poor prognosis in clinical hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the major causes of tumor death; thus, the identification of markers related to its diagnosis and prognosis is critical. Previous studies have revealed that epithelial-to-mesenchymal transition (EMT) is involved in tumor invasion and metastasis, and the forkhead box protein C2 (FOXC2) has been shown to promote tumor cell proliferation, invasion, and EMT. In the present study, we examined the clinicopathological significance of FOXC2 and EMT-related markers in clinical HCC specimens and identified factors related to the diagnosis and prognosis of HCC.

Methods

The expression of FOXC2 and EMT-related markers was evaluated by immunohistochemistry in 84 cases of hepatocellular carcinoma.

Results

A high expression of FOXC2 was observed in 26 of 84 cases, and expression was significantly correlated with background liver cirrhosis, poor tumor differentiation, high serum AFP, and elevated cell proliferation markers. In addition, this high expression was related to the induction of the Cadherin switch and vimentin expression and was an independent predictor for poor prognosis.

Conclusion

The high expression of FOXC2 in HCC is correlated with tumor malignancy and poor prognosis, suggesting that FOXC2 may be an important prognostic factor for HCC.