Annexin A2 interacting with ELMO1 regulates HCC chemotaxis and metastasis. Life Sci. 2019;222:168-174. [PMID: 30853625 DOI: 10.1016/j.lfs.2019.03.003]

Annexin A2: the feasibility of being a therapeutic target associated with cancer metastasis and drug resistance in cancer microenvironment

At present, there is still a lack of effective treatment strategies for cancer metastasis and drug resistance, so finding effective biomarkers is particularly important. AnnexinA2 (ANXA2), a vital membrane protein, critically influences cancer progression, tumor invasion, and tumor microenvironment modulation. To assess the possible application of ANXA2 as a therapeutic target against cancer cell metastasis and drug resistance to chemotherapeutic drugs in the tumor microenvironment, we elucidated the functionality of ANXA2 in stromal cells, angiogenic vascular cells, and infiltrated immune cells that mediate metastasis and drug resistance, as well as its potential as a therapeutic target. ANXA2 shows a high expression level in many tissues, and its expression level is even higher in several tumors and their microenvironments. ANXA2 is a crucial regulator of many factors and may serve as a target against drug-resistant cancers.

Nucleophosmin 1 associating with engulfment and cell motility protein 1 regulates hepatocellular carcinoma cell chemotaxis and metastasis

The chemokine, C-X-C motif chemokine ligand 12 (CXCL12) and its G-protein-coupled receptor (GPCR) and C-X-C chemokine receptor type 4 (CXCR4), are closely associated with promoting hepatocellular carcinoma (HCC) chemotaxis and metastasis. The binding of CXCL12 and CXCR4 depends on the heterotrimeric Gi proteins to regulate actin polymerisation and mobility in HCC. Although the role of GPCR/Gi signalling in carcinogenesis migration has been intensively studied, the detailed mechanism remains largely unknown. In this study, a small interfering RNA technique was used to knock down the Nucleophosmin 1 (NPM1) gene expression. Through the chemotaxis and invasion assays, wound healing, proliferation, filamentous-actin, immunofluorescence, immunohistochemical assays, and co-immunoprecipitation assays, we investigated the specific biological role and underlying mechanisms of the NPM1 in HCC. Additionally, dimethyl fumarate (DMF), a fumaric acid ester, was used to inhibit the HCC cell chemokines and metastasis by regulating ELMO1 and NPM1. Therefore, this study reported that NPM1 gene expression was upregulated in the HCC tissues and cell lines. The NPM1 knockdown significantly inhibited the proliferation, migration, and chemotaxis of the HepG2 cells in vitro. Further mechanistic studies suggested that the NPM1 interacts with ELMO1 and the CXCL12/CXCR4 pathway activates NPM1-dependent regulation of the ELMO1 localisation. Furthermore, the DMF significantly inhibited tumour metastasis induced by the NPM1/ELMO1 signalling pathway, as observed in in vitro cell functional experiments. These data suggested that as a potentially novel therapeutic approach, the simultaneous targeting of NPM1 and ELMO1 could effectively be used to treat HCC.

Prognostic Role of Molecular and Imaging Biomarkers for Predicting Advanced Hepatocellular Carcinoma Treatment Efficacy

Hepatocellular carcinoma (HCC) is the sixth most common malignancy worldwide and the fourth cause of tumor-related death. Imaging biomarkers are based on computed tomography, magnetic resonance, and contrast-enhanced ultrasound, and are widely applied in HCC diagnosis and treatment monitoring. Unfortunately, in the field of molecular biomarkers, alpha-fetoprotein (AFP) is still the only recognized tool for HCC surveillance in both diagnostic and follow-up purposes. Other molecular biomarkers have little roles in clinical practice regarding HCC, mainly for the detection of early-stage HCC, monitoring the response to treatments and analyzing tumor prognosis. In the last decades no important improvements have been achieved in this field and imaging biomarkers maintain the primacy in HCC diagnosis and follow-up. Despite the still inconsistent role of molecular biomarkers in surveillance and early HCC detection, they could play an outstanding role in prognosis estimation and treatment monitoring with a potential reduction in health costs faced by standard radiology. An important challenge resides in identifying sufficiently sensitive and specific biomarkers for advanced HCC for prognostic evaluation and detection of tumor progression, overcoming imaging biomarker sensitivity. The aim of this review is to analyze the current molecular and imaging biomarkers in advanced HCC.

Role of ELMO1 in inflammation and cancer-clinical implications

BACKGROUND

Engulfment and cell motility protein 1 (ELMO1) is a key protein for innate immunity since it is required for the clearance of apoptotic cells and pathogenic bacteria as well as for the control of inflammatory responses. ELMO1, through binding with Dock180 and activation of the Rac1 signaling pathway, plays a significant role in cellular shaping and motility. Rac-mediated actin cytoskeletal rearrangement is essential for bacterial phagocytosis, but also plays a crucial role in processes such as cancer cell invasion and metastasis. While the role of ELMO1 in bacterial infection and inflammatory responses is well established, its implication in cancer is not widely explored yet. Molecular changes or epigenetic alterations such as DNA methylation, which ultimately leads to alterations in gene expression and deregulation of cellular signaling, has been reported for ELMO1 in different cancer types.

CONCLUSIONS

In this review, we provide an updated and comprehensive summary of the roles of ELMO1 in infection, inflammatory diseases and cancer. We highlight the possible mechanisms regulated by ELMO1 that are relevant for cancer development and progression and provide insight into the possible use of ELMO1 as a diagnostic biomarker and therapeutic target.

C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C motif chemokine receptor 7(CXCR7) regulates epithelial-mesenchymal transition process and promotes the metastasis of esophageal cancer by activating signal transducer and activator of transcription 3 (STAT3) pathway

Esophageal cancer is a malignant tumor of the digestive system that is prone to metastasis. Chemokines and their receptors act an essential role in the occurrence and development of tumors. Here, we investigated the regulatory mechanism of CXCL12/CXCR7 in the growth and metastasis of esophageal cancer. CXCR7 was found highly expressed in clinical tissues and cells of esophageal cancer. Knockdown of CXCR7 inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) process of esophageal cancer cells. The knockdown of chemokine CXCL12 also inhibited the expression of EMT-related proteins and the mesenchymal morphology changes of esophageal cancer cells, but the knockdown of C-X-C motif chemokine receptor 4 (CXCR4) had no such effect. Furthermore, the knockdown of CXCR7 attenuated the enhanced EMT process induced by CXCL12 overexpression, while the knockdown of CXCR4 cannot inhibit this process. In addition, overexpressed CXCL12/CXCR7 activated the downstream STAT3 pathway, but had little effect on the extracellular regulated protein kinase (ERK) or serine-threonine kinase (AKT) pathways. Inhibition of the STAT3 pathway using AZD9150 weakened the accelerated effects of CXCL12/CXCR7 on the growth and metastasis of esophageal cancer in vitro and in vivo. In conclusion, our research revealed that CXCL12/CXCR7 regulates EMT and other malignant processes by activating the STAT3 pathway to accelerate the growth and metastasis of esophageal cancer.

Novel oncogenes and tumor suppressor genes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a very deadly disease. HCC initiation and progression involve multiple genetic events, including the activation of proto-oncogenes and disruption of the function of specific tumor suppressor genes. Activation of oncogenes stimulates cell growth and survival, while loss-of-function mutations of tumor suppressor genes result in unrestrained cell growth. In this review, we summarize the new findings that identified novel proto-oncogenes and tumor suppressors in HCC over the past five years. These findings may inspire the development of novel therapeutic strategies to improve the outcome of HCC patients.

Emerging Importance of Chemokine Receptor CXCR4 and Its Ligand in Liver Disease

Chemokine receptors are members of the G protein-coupled receptor superfamily, which together with chemokine ligands form chemokine networks to regulate various cellular functions, immune and physiological processes. These receptors are closely related to cell movement and thus play a vital role in several physiological and pathological processes that require regulation of cell migration. CXCR4, one of the most intensively studied chemokine receptors, is involved in many functions in addition to immune cells recruitment and plays a pivotal role in the pathogenesis of liver disease. Aberrant CXCR4 expression pattern is related to the migration and movement of liver specific cells in liver disease through its cross-talk with a variety of significant cell signaling pathways. An in-depth understanding of CXCR4-mediated signaling pathway and its role in liver disease is critical to identifying potential therapeutic strategies. Current therapeutic strategies for liver disease mainly focus on regulating the key functions of specific cells in the liver, in which the CXCR4 pathway plays a crucial role. Multiple challenges remain to be overcome in order to more effectively target CXCR4 pathway and identify novel combination therapies with existing strategies. This review emphasizes the role of CXCR4 and its important cell signaling pathways in the pathogenesis of liver disease and summarizes the targeted therapeutic studies conducted to date.

Multi-Omics Integrative Analysis Uncovers Molecular Subtypes and mRNAs as Therapeutic Targets for Liver Cancer

Objective: This study aimed to systematically analyze molecular subtypes and therapeutic targets of liver cancer using integrated multi-omics analysis.

Methods: DNA copy number variations (CNVs), simple nucleotide variations (SNVs), methylation, transcriptome as well as corresponding clinical information for liver carcinoma were retrieved from The Cancer Genome Atlas (TCGA). Multi-omics analysis was performed to identify molecular subtypes of liver cancer via integrating CNV, methylation as well as transcriptome data. Immune scores of two molecular subtypes were estimated using tumor immune estimation resource (TIMER) tool. Key mRNAs were screened and prognosis analysis was performed, which were validated using RT-qPCR. Furthermore, mutation spectra were analyzed in the different subtypes.

Results: Two molecular subtypes (iC1 and iC2) were conducted for liver cancer. Compared with the iC2 subtype, the iC1 subtype had a worse prognosis and a higher immune score. Two key mRNAs (ANXA2 and CHAF1B) were significantly related to liver cancer patients' prognosis, which were both up-regulated in liver cancer tissues in comparison to normal tissues. Seventeen genes with p < 0.01 differed significantly for SNV loci between iC1 and iC2 subtypes.

Conclusion: Our integrated multi-omics analyses provided new insights into the molecular subtypes of liver cancer, helping to identify novel mRNAs as therapeutic targets and uncover the mechanisms of liver cancer.

TRIM21-regulated Annexin A2 plasma membrane trafficking facilitates osteosarcoma cell differentiation through the TFEB-mediated autophagy

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents, which is characterized by dysfunctional autophagy and poor differentiation. Our recent studies have suggested that the tripartite motif containing-21 (TRIM21) plays a crucial role in regulating OS cell senescence and proliferation via interactions with several proteins. Yet, its implication in autophagy and differentiation in OS is largely unknown. In the present study, we first showed that TRIM21 could promote OS cell autophagy, as determined by the accumulation of LC3-II, and the degradation of cargo receptor p62. Further, we were able to identify that Annexin A2 (ANXA2), as a novel interacting partner of TRIM21, was critical for TIRM21-induced OS cell autophagy. Although TRIM21 had a negligible effect on the mRNA and protein expressions of ANXA2, we did find that TRIM21 facilitated the translocation of ANXA2 toward plasma membrane (PM) in OS cells through a manner relying on TRIM21-mediated cell autophagy. This functional link has been confirmed by observing a nice co-expression of TRIM21 and ANXA2 (at the PM) in the OS tissues. Mechanistically, we demonstrated that TRIM21, via facilitating the ANXA2 trafficking at the PM, enabled to release the transcription factor EB (TFEB, a master regulator of autophagy) from the ANXA2-TFEB complex, which in turn entered into the nucleus for the regulation of OS cell autophagy. In accord with previous findings that autophagy plays a critical role in the control of differentiation, we also demonstrated that autophagy inhibited OS cell differentiation, and that the TRIM21/ANXA2/TFEB axis is implicated in OS cell differentiation through the coordination with autophagy. Taken together, our results suggest that the TRIM21/ANXA2/TFEB axis is involved in OS cell autophagy and subsequent differentiation, indicating that targeting this signaling axis might lead to a new clue for OS treatment.

Annexin A2 promotion of hepatocellular carcinoma tumorigenesis via the immune microenvironment

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with a dismal prognosis, especially when diagnosed at advanced stages. Annexin A2 (ANXA2), is found to promote cancer progression and therapeutic resistance. However, the underlining mechanisms of ANXA2 in immune escape of HCC remain poorly understood up to now. Herein, we summarized the molecular function of ANXA2 in HCC and its relationship with prognosis. Furthermore, we tentatively elucidated the underlying mechanism of ANXA2 immune escape of HCC by upregulating the proportion of regulatory T cells and the expression of several inhibitory molecules, and by downregulating the proportion of natural killer cells and dendritic cells and the expression of several inhibitory molecules or effector molecules. We expect a lot of in-depth studies to further reveal the underlying mechanism of ANXA2 in immune escape of HCC in the future.

ELMO2 association with Gαi2 regulates pancreatic cancer cell chemotaxis and metastasis

Background

Pancreatic cancer is a highly lethal disease. Nearly half of the patients have distant metastasis and remain asymptomatic. Emerging evidence suggests that the chemokine, CXCL12, has a role in cancer metastasis. The interaction between CXCL12 and CXCR4 activates heterotrimeric G proteins, which regulates actin polymerization and cancer cell migration. However, the molecular mechanisms underlying pancreatic cancer cell migration are still largely obscure. Here, we addressed the role of ELMO2 in chemotaxis and metastasis of pancreatic cancer cells.

Methods

Pancreatic cancer cell lines PANC-1 and AsPC-1 and siRNA-mediated knockdown of ELMO2 were used to determine the effects of ELMO2 on cancer cell chemotaxis, invasion, migration. Co-immunoprecipitation assays were carried out to identify interacting partners of ELMO2.

Results

ELMO2 knockdown inhibited pancreatic cancer cell chemotaxis, migration, invasion, and F-actin polymerization. Co-immunoprecipitation assays revealed that ELMO2 interacted with Gαi2 and that CXCL12 triggered Gα i2-dependent membrane translocation of ELMO2. Thus, ELMO2 is a potential therapeutic target for pancreatic cancer.

CXCL12/CXCR4 axis in the microenvironment of solid tumors: A critical mediator of metastasis

Tumors are dynamic tissue masses, so requiring continuous exposure to the host cells, nurturing them into pave a path for tumor growth and metastasis. C-X-C chemokine ligand 12 (CXCL12)/C-X-C chemokine receptor type 4 (CXCR4) is the key signaling for such aim. Gathering knowledge about the activity within this axis would deepen our insight into the utmost importance this signaling taken to attract and cross-connect multiple cells within the tumor microenvironment (TME) aiming for tumor progression and metastasis. The concept behind this review is to underscore the multi-tasking roles taken by CXCL12/CXCR4 signaling in tumor metastasis, and to also suggest some strategies to target the activities within this axis.

Long noncoding RNA cytoskeleton regulator RNA promotes cell invasion and metastasis by titrating miR-613 to regulate ANXA2 in nasopharyngeal carcinoma

Background

Nasopharyngeal carcinoma (NPC) is one of the most frequent head and neck malignant tumors. Long noncoding RNAs play critical roles in tumorigenesis.

Methods

Real‐time quantitative PCR arrays were used to evaluate the expression levels of cytoskeleton regulator RNA (CYTOR) in NPC tissues and cells. Cell counting kit‐8 and colony formation analyses were used to test the NPC cell viability, while wound healing and transwell assays were employed to detect cell invasion and migration ability. Luciferase reporter assay and Western blot analyses were employed to explore the relationships among CYTOR, miR‐613, and ANXA2.

Results

We found that CYTOR expression was elevated both in NPC tissues and cells. Functional assays revealed that CYTOR promoted the invasion and migration of NPC cells. The established spontaneous lymph node metastasis model also confirmed that CYTOR promoted NPC cell metastasis in vivo. Mechanically, we found that the subcellular localization of CYTOR mostly occurred in the cell cytoplasm. Luciferase reporter and RIP assays confirmed that CYTOR functioned as the molecular sponge of miR‐613. Subsequent experiments confirmed that ANXA2 was directly targeted by miR‐613. Gain‐ and loss‐of‐function studies further confirmed that CYTOR induced the upregulation of ANXA2 by competitively binding to miR‐613, thus leading to NPC metastasis.

Conclusion

Our results highlight the importance of CYTOR in NPC development and provide new insights into potential therapeutic targets for NPC.

Epigenetic changes in fibroblasts drive cancer metabolism and differentiation

Genomic changes that drive cancer initiation and progression contribute to the co-evolution of the adjacent stroma. The nature of the stromal reprogramming involves differential DNA methylation patterns and levels that change in response to the tumor and systemic therapeutic intervention. Epigenetic reprogramming in carcinoma-associated fibroblasts are robust biomarkers for cancer progression and have a transcriptional impact that support cancer epithelial progression in a paracrine manner. For prostate cancer, promoter hypermethylation and silencing of the RasGAP, RASAL3 that resulted in the activation of Ras signaling in carcinoma-associated fibroblasts. Stromal Ras activity initiated a process of macropinocytosis that provided prostate cancer epithelia with abundant glutamine for metabolic conversion to fuel its proliferation and a signal to transdifferentiate into a neuroendocrine phenotype. This epigenetic oncogenic metabolic/signaling axis seemed to be further potentiated by androgen receptor signaling antagonists and contributed to therapeutic resistance. Intervention of stromal signaling may complement conventional therapies targeting the cancer cell.