EMT Transition States during Tumor Progression and Metastasis

Epithelial to Mesenchymal Transition: Key Regulator of Pancreatic Ductal Adenocarcinoma Progression and Chemoresistance

Simple Summary

Pancreatic ductal adenocarcinoma’s (PDAC) dismal prognosis is associated with its aggressive biological behavior and resistance to chemotherapy. Epithelial to mesenchymal transition (EMT) has been recognized as a key driver of PDAC progression and development of drug resistance. EMT is a transient and reversible process leading to transdifferentiation of epithelial cells into a more mesenchymal phenotype. It is regulated by multiple signaling pathways that control the activity of a transcription factors network. Activation of EMT in pre-invasive stages of PDAC has been accused for early dissemination. Furthermore, it contributes to the development of intratumoral heterogeneity and drug resistance. This review summarizes the available data regarding signaling networks regulating EMT and describes the integral role of EMT in different aspects of PDAC pathogenesis.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies, characterized by aggressive biological behavior and a lack of response to currently available chemotherapy. Emerging evidence has identified epithelial to mesenchymal transition (EMT) as a key driver of PDAC progression and a central regulator in the development of drug resistance. EMT is a reversible transdifferentiation process controlled by complex interactions between multiple signaling pathways such as TGFb, Wnt, and Notch, which converge to a network of specific transcription factors. Activation of EMT transcriptional reprogramming converts cancer cells of epithelial differentiation into a more mesenchymal phenotypic state. EMT occurrence in pre-invasive pancreatic lesions has been implicated in early PDAC dissemination. Moreover, cancer cell phenotypic plasticity driven by EMT contributes to intratumoral heterogeneity and drug tolerance and is mechanistically associated with the emergence of cells exhibiting cancer stem cells (CSCs) phenotype. In this review we summarize the available data on the signaling cascades regulating EMT and the molecular isnteractions between pancreatic cancer and stromal cells that activate them. In addition, we provide a link between EMT, tumor progression, and chemoresistance in PDAC.

Biological and clinical implications of metastasis-associated circular RNAs in oesophageal squamous cell carcinoma

Oesophageal squamous cell carcinoma (OSCC) is a prevalent malignancy with high morbidity and mortality as a result of early metastasis and poor prognosis. Metastasis is a multistep process, involving various signalling pathways. Circular RNAs (circRNAs) are a class of covalently closed noncoding RNAs, the aberrant expression of which is reported to be involved in several biological events, including cell transformation, proliferation, migration, invasion, apoptosis and metastasis. Several studies have reported interactions between circRNAs and metastasis-associated signalling pathways. The abundance, stability and highly specific expression of candidate circRNAs make them potential biomarkers and therapeutic targets in OSCC. In this review article, we comprehensively describe metastasis-related circRNAs and their interactions with epithelial-mesenchymal transition-associated molecules. We also describe the molecular mechanisms and clinical relevance of circRNAs in OSCC progression and metastasis.

HOXD9‑induced SCNN1A upregulation promotes pancreatic cancer cell proliferation, migration and predicts prognosis by regulating epithelial‑mesenchymal transformation

Pancreatic cancer (PC) is a malignant tumor disease, whose molecular mechanism is not fully understood. Sodium channel epithelial 1α subunit (SCNN1A) serves an important role in tumor progression. The current study explored the role of homeobox D9 (HOXD9) and SCNN1A in the progression of PC. The expression of SCNN1A and HOXD9 in PC samples was predicted on online databases and detected in PC cell lines. The association between SCNN1A expression and PC prognosis was examined by the Gene Expression Profiling Interactive Analysis, The Cancer Genome Atlas and Genotype‑Tissue Expression databases and by a Kaplan‑Meier plotter. Subsequently, the biological effects of SCNN1A on PC cell growth, colony formation, migration and invasion were investigated through RNA interference and cell transfection. Next, the expression of E‑cadherin, N‑cadherin, Vimentin and Snail was detected by western blotting to discover whether HOXD9 dysregulation mediated PC metastasis. Binding sites of HOXD9 and SCNN1A promoters were predicted on JASPAR. Reverse transcription‑quantitative PCR and western blotting were used to detect the expression level of SCNN1A following interference and overexpression of HOXD9. Luciferase assay detected luciferase activity following interference with HOXD9 and the transcriptional activity of SCNN1A following binding site deletion. High expression of SCNN1A and HOXD9 in PC was predicted by online databases, signifying poor prognosis. The present study confirmed the above predictions in PC cell lines. Knockdown of SCNN1A and HOXD9 could effectively inhibit the proliferation, migration, invasion and epithelial‑mesenchymal transition of PC cells. Furthermore, HOXD9 activated SCNN1A transcription, forming a feedback regulatory loop. HOXD9 was demonstrated to activate SCNN1A and promote the malignant biological process of PC.

Deciphering the molecular mechanism of the cancer formation by chromosome structural dynamics

Cancer reflects the dysregulation of the underlying gene network, which is strongly related to the 3D genome organization. Numerous efforts have been spent on experimental characterizations of the structural alterations in cancer genomes. However, there is still a lack of genomic structural-level understanding of the temporal dynamics for cancer initiation and progression. Here, we use a landscape-switching model to investigate the chromosome structural transition during the cancerization and reversion processes. We find that the chromosome undergoes a non-monotonic structural shape-changing pathway with initial expansion followed by compaction during both of these processes. Furthermore, our analysis reveals that the chromosome with a more expanding structure than those at both the normal and cancer cell during cancerization exhibits a sparse contact pattern, which shows significant structural similarity to the one at the embryonic stem cell in many aspects, including the trend of contact probability declining with the genomic distance, the global structural shape geometry and the spatial distribution of loci on the chromosome. In light of the intimate structure-function relationship at the chromosomal level, we further describe the cell state transition processes by the chromosome structural changes, suggesting an elevated cell stemness during the formation of the cancer cells. We show that cell cancerization and reversion are highly irreversible processes in terms of the chromosome structural transition pathways, spatial repositioning of chromosomal loci and hysteresis loop of contact evolution analysis. Our model draws a molecular-scale picture of cell cancerization from the chromosome structural perspective. The process contains initial reprogramming towards the stem cell followed by the differentiation towards the cancer cell, accompanied by an initial increase and subsequent decrease of the cell stemness.

Exploiting differential effects of actomyosin contractility to control cell sorting among breast cancer cells

In order to gain a greater understanding of the factors that drive spatial organization in multicellular aggregates of cancer cells, we investigate the segregation patterns of 6 breast cell lines of varying degree of mesenchymal character during formation of mixed aggregates. Cell sorting is considered in the context of available adhesion proteins and cellular contractility. It is found that the primary compaction mediator (cadherins or integrins) for a given cell type in isolation plays an important role in compaction speed, which in turn is the major factor dictating preference for interior or exterior position within mixed aggregates. In particular, cadherin-deficient, invasion-competent cells tend to position towards the outside of aggregates, facilitating access to extracellular matrix. Reducing actomyosin contractility is found to have a differential effect on spheroid formation depending on compaction mechanism. Inhibition of contractility has a significant stabilizing effect on cell-cell adhesions in integrin-driven aggregation and a mildly destabilizing effect in cadherin-based aggregation. This differential response is exploited to statically control aggregate organization and dynamically rearrange cells in pre-formed aggregates. Sequestration of invasive cells in the interior of spheroids provides a physical barrier that reduces invasion in three-dimensional culture, revealing a potential strategy for containment of invasive cell types.

Non-coding RNA-mediated autophagy in cancer: A protumor or antitumor factor?

Autophagy, usually referred to as macroautophagy, is a cytoprotective behavior that helps cells, especially cancer cells, escape crises. However, the role of autophagy in cancer remains controversial. The induction of autophagy is favorable for tumor growth, as it can degrade damaged cell components accumulated during nutrient deficiency, chemotherapy, or other stresses in a timely manner. Whereas the antitumor effect of autophagy might be closely related to its crosstalk with metabolism, immunomodulation, and other pathways. Recent studies have verified that lncRNAs and circRNAs modulate autophagy in carcinogenesis, cancer cells proliferation, apoptosis, metastasis, and chemoresistance via multiple mechanisms. A comprehensive understanding of the regulatory relationships between ncRNAs and autophagy in cancer might resolve chemoresistance and also offer intervention strategies for cancer therapy. This review systematically displays the regulatory effects of lncRNAs and circRNAs on autophagy in the contexts of cancer initiation, progression, and resistance to chemo- or radiotherapy and provides a novel insight into cancer therapy.

Berberine Suppresses EMT in Liver and Gastric Carcinoma Cells through Combination with TGFβR Regulating TGF-β/Smad Pathway

Berberine (BBR), a natural alkaloid derived from Coptis, has anticancer activity. Some researchers have found that it could restrain epithelial-mesenchymal transition (EMT) of melanoma, neuroblastoma, and other tumor cells. However, it is unclear whether BBR can reverse EMT in hepatocellular carcinoma (HCC) and gastric carcinoma (GC). In our study, BBR inhibited the migration and invasion of HepG2, MGC803, and SGC7901 cells in a dose-dependent manner. Transcription sequencing assays showed that Vimentin, MMP, and Smad3 were downregulated, but Smad2, Smad6, TAB2, ZO-1, and claudin 7 were upregulated when treated with BBR. GO Enrichment analysis of KEGG pathway showed that BBR significantly inhibited TGF-β/Smad at 12 h, then, PI3K/Akt and Wnt/β-catenin signaling pathways at 24 h, which were closely related to the proliferation, migration, and EMT. The results of the transcriptome sequencing analysis were verified by Western Blot. It showed that the expression of epithelial marker E-cadherin and ZO-1 remarkably augmented with BBR treatment, as well as declined mesenchymal markers, including N-cadherin and Vimentin, decreased transcription factor Snail and Slug. The effects of BBR were similar to those of the PI3K inhibitor LY294002 and TGF-β receptor inhibitor SB431542. Furthermore, β-catenin and phosphorylation of AKT, Smad2, and Smad3 were changed dose-dependently by BBR treatment, which upregulated p-Smad2 and downregulated the others. Combined with LY or SB, respectively, BBR could enhance the effects of the two inhibitors. Simultaneously, IGF-1 and TGF-β, which is the activator of PI3K/AKT and TGF-β/Smad, respectively, could reverse the anti-EMT effect of BBR. The Molecular Docking results showed BBR had a high affinity with the TGF-β receptor I (TGFβR1), and the binding energy was -7.5 kcal/mol, which is better than the original ligand of TGFβR1. Although the affinity of BBR with TGF-β receptor II (TGFβR2) was lower than the original ligand of TGFβR2, the more considerable negative binding energy (-8.54 kcal/mol) was obtained. BBR upregulated p-Smad2, which was different from other reports, indicating that the function of Smad2 was relatively complex. Combination BBR with SB could enhance the effect of the inhibitor on EMT, and the results indicated that BBR binding to TGFβR was not competitive with SB to TGFβR since different binding amino acid sites. Our experiments demonstrated BBR increased p-Smad2 and decreased p-Smad3 by binding to TGFβR1 and TGβFR2 inhibiting TGF-β/Smad, then, PI3K/AKT and other signaling pathways to restrain EMT, metastasis, and invasion in tumor cells. The effect of BBR was similar on the three tumor cells.

Mechanotransduction in fibrosis: Mechanisms and treatment targets

To perceive and integrate the environmental cues, cells and tissues sense and interpret various physical forces like shear, tensile, and compression stress. Mechanotransduction involves the sensing and translation of mechanical forces into biochemical and mechanical signals to guide cell fate and achieve tissue homeostasis. Disruption of this mechanical homeostasis by tissue injury elicits multiple cellular responses leading to pathological matrix deposition and tissue stiffening, and consequent evolution toward pro-inflammatory/pro-fibrotic phenotypes, leading to tissue/organ fibrosis. This review focuses on the molecular mechanisms linking mechanotransduction to fibrosis and uncovers the potential therapeutic targets to halt or resolve fibrosis.

Exosomal circular RNAs: A new frontier in the metastasis of digestive system tumors

Exosomes are membrane vesicles with a diameter of 30–150 nm. Exosomes are secreted by various types of tumor cell and contain a variety of proteins, circular RNAs (circRNAs), microRNAs and DNA, depending on the host cells. Among them, circRNAs, which are long non-coding endogenous RNAs, form covalently closed and continuous loops that link the 3′ and 5′ terminals generated by back-splicing. circRNAs have become a hotspot of research. Exosomal circRNAs are in volved in the pathogenesis of cancer, especially metastasis, which is mainly ascribed to the frequently abnormal expression levels within neoplasms. Nonetheless, the functions and regulatory mechanisms of exosomal circRNAs in the progression of digestive system tumors (DSTs) remain unclear. More knowledge on the regulation and network interactions of exosomal circRNAs will help identify superior treatment strategies for the metastasis of DSTs. The present review aims to summarize the existing studies on the functions and mechanisms of exosomal circRNAs in tumorigenesis, and evaluate the associations between the dysregulation of exosomal circRNAs and tumor metastasis.

SC66 inhibits the proliferation and induces apoptosis of human bladder cancer cells by targeting the AKT/β-catenin pathway

Bladder cancer (BC) is a major disease of the genitourinary tract, and chemotherapy is one of the main treatments commonly used at present. SC66 is a new type of allosteric AKT inhibitor that is reported to play an effective inhibitory role in the progression of many other types of tumours, but there is no reported research on its role in BC. In this study, we found that SC66 significantly inhibited the proliferation and EMT‐mediated migration and invasion of T24 and 5637 cells. In addition, experiments confirmed that SC66 achieved its antitumour effect by inducing cell apoptosis and affecting the cell cycle. Luciferase assays confirmed that SC66 exerted an antitumour effect through the AKT/β‐catenin signalling pathway, and this inhibitory effect was reversed after the addition of the β‐catenin signalling pathway activator, CHIR‐99021. In addition, animal studies have shown that, compared with the control group, the experimental group with SC66 intraperitoneal injection showed significantly reduced the tumour weight and volume in nude mice with T24 tumours and that SC66 combined with cisplatin achieved better inhibition on tumours. Western blot analysis and immunohistochemistry staining confirmed that SC66 inhibited the EMT process in vivo and induced apoptosis through the AKT/β‐catenin signalling pathway. In conclusion, our study demonstrated that SC66 exerts a significant antitumour effect through the AKT/β‐catenin signalling pathway, thereby providing a new potential treatment for BC.

Repurposing Disulfiram for Targeting of Glioblastoma Stem Cells: An In Vitro Study

Mesenchymal glioblastoma stem cells (GSCs), a subpopulation in glioblastoma that are responsible for therapy resistance and tumor spreading in the brain, reportedly upregulate aldehyde dehydrogenase isoform-1A3 (ALDH1A3) which can be inhibited by disulfiram (DSF), an FDA-approved drug formerly prescribed in alcohol use disorder. Reportedly, DSF in combination with Cu2+ ions exerts multiple tumoricidal, chemo- and radio-therapy-sensitizing effects in several tumor entities. The present study aimed to quantify these DSF effects in glioblastoma stem cells in vitro, regarding dependence on ALDH1A3 expression. To this end, two patient-derived GSC cultures with differing ALDH1A3 expression were pretreated (in the presence of CuSO4, 100 nM) with DSF (0 or 100 nM) and the DNA-alkylating agent temozolomide (0 or 30 µM) and then cells were irradiated with a single dose of 0-8 Gy. As read-outs, cell cycle distribution and clonogenic survival were determined by flow cytometry and limited dilution assay, respectively. As a result, DSF modulated cell cycle distribution in both GSC cultures and dramatically decreased clonogenic survival independently of ALDH1A3 expression. This effect was additive to the impairment of clonogenic survival by radiation, but not associated with radiosensitization. Of note, cotreatment with temozolomide blunted the DSF inhibition of clonogenic survival. In conclusion, DSF targets GSCs independent of ALDH1A3 expression, suggesting a therapeutic efficacy also in glioblastomas with low mesenchymal GSC populations. As temozolomide somehow antagonized the DSF effects, strategies for future combination of DSF with the adjuvant standard therapy (fractionated radiotherapy and concomitant temozolomide chemotherapy followed by temozolomide maintenance therapy) are not supported by the present study.

Integrated computational analyses reveal novel insights into the stromal microenvironment of SHH-subtype medulloblastoma

Medulloblastoma is the most common malignant brain tumour of childhood. While our understanding of this disease has progressed substantially in recent years, the role of tumour microenvironment remains unclear. Given the increasing role of microenvironment-targeted therapeutics in other cancers, this study was aimed at further exploring its role in medulloblastoma. Multiple computational techniques were used to analyze open-source bulk and single cell RNA seq data from primary samples derived from all subgroups of medulloblastoma. Gene expression is used to infer stromal subpopulations, and network-based approaches are used to identify potential therapeutic targets. Bulk data was obtained from 763 medulloblastoma samples and single cell data from an additional 7241 cells from 23 tumours. Independent bulk (285 tumours) and single cell (32,868 cells from 29 tumours) validation cohorts were used to verify results. The SHH subgroup was found to be enriched in stromal activity, including the epithelial-to-mesenchymal transition, while group 3 is comparatively stroma-suppressed. Several receptor and ligand candidates underlying this difference are identified which we find to correlate with metastatic potential of SHH medulloblastoma. Additionally, a biologically active gradient is detected within SHH medulloblastoma, from "stroma-active" to "stroma-suppressed" cells which may have relevance to targeted therapy. This study serves to further elucidate the role of the stromal microenvironment in SHH-subgroup medulloblastoma and identify novel treatment possibilities for this challenging disease.

Low Expression of Stanniocalcin 1 (STC-1) Protein Is Associated With Poor Clinicopathologic Features of Endometrial Cancer

Stanniocalcin-1 (STC-1) is a glycoprotein hormone involved in diverse biological processes, including regulation of calcium phosphate homeostasis, cell proliferation, apoptosis, inflammation, oxidative stress responses, and cancer development. The role of STC-1 in endometrial cancer (EC) is yet to be elucidated. In this study, we investigated the protein expression pattern of STC-1 in a tissue microarray (TMA) cohort of hysterectomy specimens from 832 patients with EC. We then evaluated the prognostic value of STC-1 expression regarding the clinicopathologic features and patients survival over a period of 140 months. Our results revealed that in EC tissue samples, STC-1 is mainly localized in the endometrial epithelium, although some expression was also observed in the stroma. Decreased STC-1 expression was associated with factors relating to a worse prognosis, such as grade 3 endometrioid tumors (p = 0.030), deep myometrial invasion (p = 0.003), lymphovascular space invasion (p = 0.050), and large tumor size (p = 0.001). Moreover, STC-1 expression was decreased in tumors obtained from obese women (p = 0.014) and in women with diabetes mellitus type 2 (DMT2; p = 0.001). Interestingly, the data also showed an association between DNA mismatch repair (MMR) deficiency and weak STC-1 expression, specifically in the endometrial epithelium (p = 0.048). No association was observed between STC-1 expression and disease-specific survival. As STC-1 expression was particularly low in cases with obesity and DMT2 in the TMA cohort, we also evaluated the correlation between metformin use and STC-1 expression in an additional EC cohort that only included women with DMT2 (n = 111). The analysis showed no difference in STC-1 expression in either the epithelium or the stroma in women undergoing metformin therapy compared to metformin non-users. Overall, our data may suggest a favorable role for STC-1 in EC behavior; however, further studies are required to elucidate the detailed mechanism and possible applications to cancer treatment.

Total Flavonoids of Litchi Seed Attenuate Prostate Cancer Progression Via Inhibiting AKT/mTOR and NF-kB Signaling Pathways

Litchi seeds have been traditionally used in Chinese herbal formula for urologic neoplasms including prostate cancer (PCa). However, the effective components of Litchi seeds and the mechanisms of their actions on PCa cell growth and metastasis remain unclear. In this study, we investigated the effects and molecular mechanisms of the Total Flavonoid of Litchi Seed (TFLS) in PCa PC3 and DU145 cell lines. We found that TFLS significantly inhibited the PCa cell proliferation, induced apoptosis, and prevented cell migration and invasion. Furthermore, we observed that TFLS upregulated the expression of epithelial biomarker E-cadherin and downregulated mesenchymal biomarker Vimentin. TFLS also increased the expression of cleaved-PRAP and Bax, and decreased the expression of Bcl-2 in both PC3 and DU145 cells. Besides, TFLS inhibited AKT signaling pathway by reducing the phosphorylation of AKT and activities of downstream signal transducers including mTOR, IκBα and NF-kB. Finally, TFLS treated mice exhibited a significant decrease in tumor size without toxicity in major organs in vivo. These results indicated that TFLS could suppress PCa cell growth in vivo and inhibit PCa cell proliferation and metastasis in vitro through induction of apoptosis and phenotypic reversal of EMT, which may be achieved by inhibiting the AKT/mTOR and NF-κB signaling pathways. Taken together, our data provide new insights into the role of TFLS as a novel potent anti-cancer agent for the treatment of PCa.

FAM83A promotes proliferation and metastasis via Wnt/β-catenin signaling in head neck squamous cell carcinoma

This research aimed to investigate the expression and function of FAM83A in the proliferation and metastasis in head and neck squamous cell carcinoma (HNSCC). FAM83A mRNA and protein expressions in HNSCC were detected in primary HNSCC samples and cell lines. The associations between FAM83A expression and clinicopathologic variables were evaluated through tissue microarrays. Besides, FAM83A knockdown and overexpression cell lines were constructed to assess cell growth and metastasis in vitro and the relationship between FAM83A and epithelial-mesenchymal transition (EMT). Furthermore, two models of xenograft tumors in nude mice were used to assess the tumorigenicity and metastasis ability of FAM83A in vivo. In the present study, overexpression of FAM83A in HNSCC samples was significantly associated with tumor size, lymph node status and clinical tumor stages. Mechanically, FAM83A could promote HNSCC cell growth and metastasis by inducing EMT via activating Wnt/β-catenin signaling pathway. Rescue experiment demonstrated the inhibition of β-catenin could counteract the function of FAM83A. Also, the FAM83A knockdown could suppress tumor growth and distant metastasis in the xenograft animal models of HNSCC. In conclusion, this study identifies FAM83A as an oncogene of HNSCC. This study provides new insights into the molecular pathways that contribute to EMT in HNSCC. We revealed a previously unknown FAM83A-Wnt–β-catenin signaling axis involved in the EMT of HNSCC. There may be a potential bi-directional signaling loop between FAM83A and Wnt/β-catenin signaling pathway in HNSCC.

Advances in the study of emodin: an update on pharmacological properties and mechanistic basis

Rhei Radix et Rhizoma, also known as rhubarb or Da Huang, has been widely used as a spice and as traditional herbal medicine for centuries, and is currently marketed in China as the principal herbs in various prescriptions, such as Da-Huang-Zhe-Chong pills and Da-Huang-Qing-Wei pills. Emodin, a major bioactive anthraquinone derivative extracted from rhubarb, represents multiple health benefits in the treatment of a host of diseases, such as immune-inflammatory abnormality, tumor progression, bacterial or viral infections, and metabolic syndrome. Emerging evidence has made great strides in clarifying the multi-targeting therapeutic mechanisms underlying the efficacious therapeutic potential of emodin, including anti-inflammatory, immunomodulatory, anti-fibrosis, anti-tumor, anti-viral, anti-bacterial, and anti-diabetic properties. This comprehensive review aims to provide an updated summary of recent developments on these pharmacological efficacies and molecular mechanisms of emodin, with a focus on the underlying molecular targets and signaling networks. We also reviewed recent attempts to improve the pharmacokinetic properties and biological activities of emodin by structural modification and novel material-based targeted delivery. In conclusion, emodin still has great potential to become promising therapeutic options to immune and inflammation abnormality, organ fibrosis, common malignancy, pathogenic bacteria or virus infections, and endocrine disease or disorder. Scientifically addressing concerns regarding the poor bioavailability and vague molecular targets would significantly contribute to the widespread acceptance of rhubarb not only as a dietary supplement in food flavorings and colorings but also as a health-promoting TCM in the coming years.

Multifaced roles of PLAC8 in cancer

The role of PLAC8 in tumorigenesis has been gradually elucidated with the development of research. Although there are common molecular mechanisms that enforce cell growth, the impact of PLAC8 is varied and can, in some instances, have opposite effects on tumorigenesis. To systematically understand the role of PLAC8 in tumors, the molecular functions of PLAC8 in cancer will be discussed by focusing on how PLAC8 impacts tumorigenesis when it arises within tumor cells and how these roles can change in different stages of cancer progression with the ultimate goal of suppressing PLAC8-relevant cancer behavior and related pathologies. In addition, we highlight the diversity of PLAC8 in different tumors and its functional output beyond cancer cell growth. The comprehension of PLAC8's molecular function might provide new target and lead to the development of novel anticancer therapies.

E2F1-Induced lncRNA BAIAP2-AS1 Overexpression Contributes to the Malignant Progression of Hepatocellular Carcinoma via miR-361-3p/SOX4 Axis

Currently, plenty of researches have revealed that long noncoding RNAs (lncRNAs) can act as crucial roles during the progression of various tumors, including hepatocellular carcinoma (HCC). Here, we measured the expression of lncRNA BAIAP2 antisense RNA 1(BAIAP2-AS1) as well as its contribution to the developments of HCC. In this study, the expressions of BAIAP2-AS1 and SOX4 were distinctly upregulated in HCC cells and tissues, and high BAIAP2-AS1 may be a novel biomarker for HCC. E2F1 activated BAIAP2-AS1 expression. The silence of BAIAP2-AS1 inhibited the proliferation and metastasis of HepG2 and PLC5 cells. Assays for relationship verification showed that BAIAP2-AS1 regulated the expression of SOX4 and miR-361-3p. Rescue experiments further confirmed the positive interaction between miR-361-3p and BAIAP2-AS1 as well as between miR-361-3p and SOX4. Overall, BAIAP2-AS1 modulated the miR-361-3p/SOX4 axis to promote the development of HCC. Thus, our study offers a potential therapeutic target for treating HCC.

Vimentin Is at the Heart of Epithelial Mesenchymal Transition (EMT) Mediated Metastasis

Epithelial-mesenchymal transition (EMT) is a reversible plethora of molecular events where epithelial cells gain the phenotype of mesenchymal cells to invade the surrounding tissues. EMT is a physiological event during embryogenesis (type I) but also happens during fibrosis (type II) and cancer metastasis (type III). It is a multifaceted phenomenon governed by the activation of genes associated with cell migration, extracellular matrix degradation, DNA repair, and angiogenesis. The cancer cells employ EMT to acquire the ability to migrate, resist therapeutic agents and escape immunity. One of the key biomarkers of EMT is vimentin, a type III intermediate filament that is normally expressed in mesenchymal cells but is upregulated during cancer metastasis. This review highlights the pivotal role of vimentin in the key events during EMT and explains its role as a downstream as well as an upstream regulator in this highly complex process. This review also highlights the areas that require further research in exploring the role of vimentin in EMT. As a cytoskeletal protein, vimentin filaments support mechanical integrity of the migratory machinery, generation of directional force, focal adhesion modulation and extracellular attachment. As a viscoelastic scaffold, it gives stress-bearing ability and flexible support to the cell and its organelles. However, during EMT it modulates genes for EMT inducers such as Snail, Slug, Twist and ZEB1/2, as well as the key epigenetic factors. In addition, it suppresses cellular differentiation and upregulates their pluripotent potential by inducing genes associated with self-renewability, thus increasing the stemness of cancer stem cells, facilitating the tumour spread and making them more resistant to treatments. Several missense and frameshift mutations reported in vimentin in human cancers may also contribute towards the metastatic spread. Therefore, we propose that vimentin should be a therapeutic target using molecular technologies that will curb cancer growth and spread with reduced mortality and morbidity.

Vorinostat targets UBE2C to reverse epithelial-mesenchymal transition and control cervical cancer growth through the ubiquitination pathway

Vorinostat is a histone deacetylase inhibitor (HDACi) that was demonstrated in our previous study to inhibit the proliferation, migration, and invasion of cervical cancer cells by regulating the PI3K/Akt signaling pathway. However, the molecular mechanism of vorinostat in cervical cancer treatment remains to be further elucidated. A nude mouse xenograft model was established to analyze the antitumor effect of vorinostat in vivo. The combination of iTRAQ-based proteomics and parallel reaction monitoring (PRM) technology has proven to be an efficient and reliable method to identify potential targets for cancer chemotherapy. In this study, 254 differentially expressed proteins in vorinostat-treated cervical cancer cells, among which 180 were upregulated and 74 were downregulated, were identified by using an iTRAQ-based proteomic strategy. Subsequent bioinformatic and PRM analysis of these differentially expressed proteins indicated that UBE2C is a promising target of vorinostat in the inhibition of cervical cancer cell proliferation. We confirmed that the expression of endogenous UBE2C in cervical cancer cell lines was significantly higher than that in normal cervical epithelial cell lines. Additionally, we found that vorinostat downregulated the expression of UBE2C, SQSTM1/p62, N-cadherin, vimentin and upregulated E-cadherin in SiHa and HeLa cells. Our results also showed that vorinostat can downregulate the expression of SQSTM1/p62, N-cadherin, and vimentin during the treatment of cervical cancer cells by regulating UBE2C, while upregulating the expression of E-cadherin. In conclusion, vorinostat reverses epithelial-mesenchymal transition by targeting UBE2C and controls the proliferation of cervical cancer cells through the ubiquitination pathway. UBE2C can be used as a promising target for the development of vorinostat treatment strategies.

Long Non-coding RNA LINC01503 Promotes Gastric Cardia Adenocarcinoma Progression via miR-133a-5p/VIM Axis and EMT Process

BACKGROUND

LINC01503 has been reported to act as a candidate oncogenic lncRNA in several types of human cancer. However, the functions and underlying mechanisms of LINC01503 in gastric cardia adenocarcinoma (GCA) remain unclear.

AIMS

To investigate the roles and underlying mechanisms of LINC01503 in GCA progression.

MATERIALS AND METHODS

Gene expressions were detected by quantitative real-time PCR (qRT-PCR). Gain-of-function assays were performed to evaluate the function of LINC01503 in gastric cancer cells. Bioinformatics analysis, luciferase reporter assay, and RIP assay were performed to identify associations among LINC01503, miR-133a-5p, and VIM.

RESULTS

The expression level of LINC01503 was significantly elevated in GCA tissues and cell lines. High expression of LINC01503 was correlated with lymph node metastasis, TNM stage, and poor prognosis of GCA patients. Knockdown of LINC01503 significantly reduced proliferation, migration, and invasion ability in GC cells. LINC01503 might function as a competing endogenous RNA (ceRNA) via sponging miR-133a-5p to upregulate the expression of VIM. Furthermore, overexpression of LINC01503 promoted the progression of epithelial mesenchymal transition (EMT) in vitro.

CONCLUSION

LINC01503 serves as an oncogenic lncRNA to promote GCA progression via affecting LINC01503/miR-133a-5p/VIM axis and EMT process. LINC01503 not only has a critical role in GCA progression but also provide a novel potential biomarker in predicting prognosis for GCA patients.

HSPB8 promoted intrahepatic cholangiocarcinoma progression by enhancing epithelial-mesenchymal transition and autophagy

PURPOSE

Heat shock protein B8 (HSPB8) has been recently discovered to be participated in the regulation of tumor progression. However, the function of HSPB8 in intrahepatic cholangiocarcinoma (ICC) has not yet been elucidated. This study studied the function of HSPB8 in ICC progression.

METHODS

ICC patients (n = 150) were enrolled. The relationship between clinicopathological characteristics and HSPB8 expression was analyzed. RBE cells were transfected and treated by 3-MA. The RBE cells morphology was observed under a transmission electron microscope. Cell counting kit-8 assay, wound healing assay and Transwell experiment was conducted to detect RBE cells proliferation, migration and invasion. Quantitative reverse transcription-polymerase chain reaction, immunohistochemistry, Western blot and immunofluorescence were used for genes detection in clinical tissues and RBE cells.

RESULTS

HSPB8 was up-regulated in ICC tissues than that in adjacent normal tissues. High HSPB8 expression in ICC indicated poor prognosis of patients. HSPB8 expression was mainly expressed in cell cytoplasm and aberrantly increased in RBE cells (P < 0.01). HSPB8 up-regulation promoted RBE cells proliferation, migration and invasion (P < 0.05). HSPB8 down-regulation reduced RBE cells proliferation, migration and invasion (P < 0.01). HSPB8 overexpression facilitated Vimentin expression, LC3-II/LC3-I ratio and inhibited E-cadherin, p62 expression in RBE cells (P < 0.05). Treatment of 3-MA partially reversed HSPB8 promotion on RBE cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) (P < 0.05 or P < 0.01).

CONCLUSION

HSPB8 promoted ICC progression by enhancing EMT and autophagy. HSPB8 might be an effective target for ICC treatment.

New insights into BMP9 signaling in liver diseases

Bone morphogenetic protein 9 (BMP9) is a recently discovered cytokine mainly secreted by the liver and is a member of the transforming growth factor β (TGF-β) superfamily. In recent years, an increasing number of studies have shown that BMP9 is associated with liver diseases, including nonalcoholic fatty liver disease (NAFLD), liver fibrosis and hepatocellular carcinoma (HCC), and BMP9 signaling may play dual roles in liver diseases. In this review, we mainly summarized and discussed the roles and potential mechanisms of BMP9 signaling in NAFLD, liver fibrosis and HCC. Specifically, this article will provide a better understanding of BMP9 signaling and new clues for the treatment of liver diseases.

FOXP4 promotes laryngeal squamous cell carcinoma progression through directly targeting LEF‑1

Forkhead box (FOX) proteins are multifaceted transcription factors that have been shown to be involved in cell cycle progression, proliferation and metastasis. FOXP4, a member of the FOX family, has been implicated in diverse biological processes in tumor initiation and progression. However, the molecular mechanisms of FOXP4 in laryngeal squamous cell carcinoma (LSCC) remain unknown. In the present study, differentially expressed transcripts in transforming growth factor‑β‑treated TU177 cells were screened using microarrays and it was found that FOXP4 was significantly upregulated. The high expression of FOXP4 was detected in LSCC tissues and cells, and predicted poor prognosis. The role of FOXP4 in laryngeal cancer cell proliferation, migration and invasion was determined by gain‑ and loss‑of‑function assays. Besides, FOXP4 was demonstrated to participate in the epithelial‑mesenchymal transition process at the mRNA and protein levels. Mechanically, FOXP4 directly bound to the promoter of lymphoid enhancer‑binding factor 1 and activated Wnt signaling pathway, which was confirmed via chromatin immunoprecipitation and luciferase reporter assays. Consequently, these findings provided novel mechanisms of FOXP4 in LSCC progression, which may be considered as potential therapeutic and prognostic targets for LSCC.

Survival-related epithelial-mesenchymal transition proteins in oropharyngeal squamous cell carcinoma: A systematic review and meta-analysis

OBJECTIVE

To aim of this systematic review was to explore the relationship between Human papillomavirus (HPV) and epithelial-mesenchymal transition (EMT) related to the prognosis of oropharyngeal squamous cell carcinoma (OPSCC).

DESIGN

For this systematic review, searches were performed in PubMed, Web of Science, Scopus, Science Direct, and Cochrane, and a random-effects model was used for meta-analysis. The presence of EMT was confirmed by the loss of E-cadherin immunoexpression and overexpression of vimentin.

RESULTS

In summary, EMT-related proteins were expressed regardless of HPV status; however, overall survival was better in HPV-positive OPSCC cases, with a 5.88 times lower death risk compared to HPV-negative patients (OR=0.17; 95%CI=0.10-0.30). Likewise, the maintenance of E-cadherin in OPSCC was associated with an 11.11 times lower risk of death due to the disease (OR=0.09; 95%CI=0.01-0.88).

CONCLUSIONS

More advanced clinical stages (III/IV) and the presence of lymph node metastases (N1-3) were common in OPSCC but were not significantly associated with HPV status.

A new paradigm for leprosy diagnosis based on host gene expression

Transcriptional profiling is a powerful tool to investigate and detect human diseases. In this study, we used bulk RNA-sequencing (RNA-Seq) to compare the transcriptomes in skin lesions of leprosy patients or controls affected by other dermal conditions such as granuloma annulare, a confounder for paucibacillary leprosy. We identified five genes capable of accurately distinguishing multibacillary and paucibacillary leprosy from other skin conditions. Indoleamine 2,3-dioxygenase 1 (IDO1) expression alone was highly discriminatory, followed by TLR10, BLK, CD38, and SLAMF7, whereas the HS3ST2 and CD40LG mRNA separated multi- and paucibacillary leprosy. Finally, from the main differentially expressed genes (DEG) and enriched pathways, we conclude that paucibacillary disease is characterized by epithelioid transformation and granuloma formation, with an exacerbated cellular immune response, while multibacillary leprosy features epithelial-mesenchymal transition with phagocytic and lipid biogenesis patterns in the skin. These findings will help catalyze the development of better diagnostic tools and potential host-based therapeutic interventions. Finally, our data may help elucidate host-pathogen interplay driving disease clinical manifestations.

The Heterogeneity of the Tumor Microenvironment as Essential Determinant of Development, Progression and Therapy Response of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is commonly diagnosed at advanced stages and most anti-cancer therapies have failed to substantially improve prognosis of PDAC patients. As a result, PDAC is still one of the deadliest tumors. Tumor heterogeneity, manifesting at multiple levels, provides a conclusive explanation for divergent survival times and therapy responses of PDAC patients. Besides tumor cell heterogeneity, PDAC is characterized by a pronounced inflammatory stroma comprising various non-neoplastic cells such as myofibroblasts, endothelial cells and different leukocyte populations which enrich in the tumor microenvironment (TME) during pancreatic tumorigenesis. Thus, the stromal compartment also displays a high temporal and spatial heterogeneity accounting for diverse effects on the development, progression and therapy responses of PDAC. Adding to this heterogeneity and the impact of the TME, the microbiome of PDAC patients is considerably altered. Understanding this multi-level heterogeneity and considering it for the development of novel therapeutic concepts might finally improve the dismal situation of PDAC patients. Here, we outline the current knowledge on PDAC cell heterogeneity focusing on different stromal cell populations and outline their impact on PDAC progression and therapy resistance. Based on this information, we propose some novel concepts for treatment of PDAC patients.

RNF144A-AS1, a TGF-β1- and hypoxia-inducible gene that promotes tumor metastasis and proliferation via targeting the miR-30c-2-3p/LOX axis in gastric cancer

Background

Although recent molecular analyses have improved our knowledge regarding gastric cancer (GC) biology, the molecular mechanisms that confer metastatic potential to GC remain poorly understood. In this study, we intend to explore the function and characterize the underlying mechanism of long noncoding RNA RNF144A-AS1 in GC metastasis and outgrowth.

Methods

The expression of RNF144A-AS1, miR-30c-2-3p, and Lysyl oxidase (LOX) was detected by quantitative real-time PCR assay. Fluorescence in situ hybridization and subcellular fractionation assay determined the cellular localization of RNF144A-AS1. Cell counting kit 8 assay, transwell assay, and tube formation assay were performed to detect the effect on cell proliferation, migration, invasion, and angiogenesis, respectively. Animal models were also applied to verify the effect on tumor metastasis, outgrowth, and angiogenesis. Bioinformatic analysis, luciferase reporter assay, and RNA immunoprecipitation (RIP) assay explored the interactions among RNF144A-AS1, miR-30c-2-3p, and LOX. Gene regulation was further validated by knockdown of Dicer or mutating the miRNA binding sites on RNF144A-AS1 and LOX 3ʹUTR. Cells were treated with recombinant human TGF-β1 (Transforming Growth Factor β1) to explore the effect of TGF-β1 on RNF144A-AS1. Western blot and immunohistochemistry were used to detect protein expression.

Results

The expression of RNF144A-AS1 was significantly upregulated in GC tissues and was associated with poor prognosis and later-stage diseases. Hypoxia stimulated the expression of RNF144A-AS1 in a HIF-1α-independent manner. Additionally, RNF144A-AS1 was also induced by TGF-β1. Loss and gain of function assays revealed that RNF144A-AS1 promoted tumor metastasis, angiogenesis, and proliferation. Mechanism exploration indicated RNF144A-AS1 served as a microRNA decoy of miR-30c-2-3p to release LOX. Gene Set Enrichment Analysis further suggested LOX and RNF144A-AS1 were enriched in the same gene sets, emphasizing the internal mechanism connection between these two genes.

Conclusions

TGF-β1- and hypoxia-inducible RNF144A-AS1 promoted tumor metastasis, angiogenesis, and proliferation through targeting the miR-30c-2-3p/LOX axis in GC, highlighting the value of the RNF144A-AS1/miR-30c-2-3p/LOX axis in therapeutic interventions of GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00689-z.

AXL Receptor in Cancer Metastasis and Drug Resistance: When Normal Functions Go Askew

Simple Summary

AXL is a member of the TAM (TYRO3, AXL, MER) family of receptor tyrosine kinases. In normal physiological conditions, AXL is involved in removing dead cells and their remains, and limiting the duration of immune responses. Both functions are utilized by cancers in the course of tumour progression. Cancer cells use the AXL pathway to detect toxic environments and to activate molecular mechanisms, thereby ensuring their survival or escape from the toxic zone. AXL is instrumental in controlling genetic programs of epithelial-mesenchymal and mesenchymal-epithelial transitions, enabling cancer cells to metastasize. Additionally, AXL signaling suppresses immune responses in tumour microenvironment and thereby helps cancer cells to evade immune surveillance. The broad role of AXL in tumour biology is the reason why its inhibition sensitizes tumours to a broad spectrum of anti-cancer drugs. In this review, we outline molecular mechanisms underlying AXL function in normal tissues, and discuss how these mechanisms are adopted by cancers to become metastatic and drug-resistant.

Abstract

The TAM proteins TYRO3, AXL, and MER are receptor tyrosine kinases implicated in the clearance of apoptotic debris and negative regulation of innate immune responses. AXL contributes to immunosuppression by terminating the Toll-like receptor signaling in dendritic cells, and suppressing natural killer cell activity. In recent years, AXL has been intensively studied in the context of cancer. Both molecules, the receptor, and its ligand GAS6, are commonly expressed in cancer cells, as well as stromal and infiltrating immune cells. In cancer cells, the activation of AXL signaling stimulates cell survival and increases migratory and invasive potential. In cells of the tumour microenvironment, AXL pathway potentiates immune evasion. AXL has been broadly implicated in the epithelial-mesenchymal plasticity of cancer cells, a key factor in drug resistance and metastasis. Several antibody-based and small molecule AXL inhibitors have been developed and used in preclinical studies. AXL inhibition in various mouse cancer models reduced metastatic spread and improved the survival of the animals. AXL inhibitors are currently being tested in several clinical trials as monotherapy or in combination with other drugs. Here, we give a brief overview of AXL structure and regulation and discuss the normal physiological functions of TAM receptors, focusing on AXL. We present a theory of how epithelial cancers exploit AXL signaling to resist cytotoxic insults, in order to disseminate and relapse.

CMTM3 suppresses chordoma progress through EGFR/STAT3 regulated EMT and TP53 signaling pathway

BACKGROUND

Chordomas are rare, slow-growing and locally aggressive bone sarcomas. At present, chordomas are difficult to manage due to their high recurrence rate, metastasis tendency and poor prognosis. The underlying mechanisms of chordoma tumorigenesis and progression urgently need to be explored to find the effective therapeutic targets. Our previous data demonstrates that EGFR plays important roles in chordoma development and CKLF-like MARVEL transmembrane domain containing (CMTM)3 suppresses gastric cancer metastasis by inhibiting the EGFR/STAT3/EMT signaling pathway. However, the roles and mechanism of CMTM3 in chordomas remain unknown.

METHODS

Primary chordoma tissues and the paired adjacent non-tumor tissues were collected to examine the expression of CMTM3 by western blot. The expression of CMTM3 in chordoma cell lines was tested by Real-time PCR and western blot. CCK-8 and colony forming unit assay were performed to delineate the roles of CMTM3 in cell proliferation. Wound healing and Transwell assays were performed to assess cell migration and invasion abilities. A xenograft model in NSG mice was used to elucidate the function of CMTM3 in vivo. Signaling pathways were analyzed by western blot and IHC. RNA-seq was performed to further explore the mechanism regulated by CMTM3 in chordoma cells.

RESULTS

CMTM3 expression was downregulated in chordoma tissues compared with paired normal tissues. CMTM3 suppressed proliferation, migration and invasion of chordoma cells in vitro and inhibited tumor growth in vivo. CMTM3 accelerated EGFR degradation, suppressed EGFR/STAT3/EMT signaling pathway, upregulated TP53 expression and enriched the TP53 signaling pathway in chordoma cells.

CONCLUSIONS

CMTM3 inhibited tumorigenesis and development of chordomas through activating the TP53 signaling pathway and suppressing the EGFR/STAT3 signaling pathway, which suppressed EMT progression. CMTM3 might be a potential therapeutic target for chordomas.

miR-1207-5p suppresses laryngeal squamous cell carcinoma progression by downregulating SKA3 and inhibiting epithelial-mesenchymal transition

Laryngeal squamous cell carcinoma (LSCC) is the second most common head and neck cancer. Previously, we discovered that miR-1207-5p was downregulated in LSCC. In this study, the clinical significance, function, and mechanism of miR-1207-5p in LSCC were investigated. Downregulation of miR-1207-5p was found to be strongly linked to the malignant progression of LSCC. Functional studies revealed that miR-1207-5p upregulation suppressed LSCC cell proliferation, invasion, migration, and xenograft tumor growth. Bioinformatics analysis revealed that miR-1207-5p target genes were involved in cell cycle regulation, proliferation, adhesion, and the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Mechanistic studies revealed that miR-1207-5p interacts directly with the 3′ untranslated region of spindle and kinetochore associated complex subunit 3 (SKA3) and downregulates SKA3 expression. Furthermore, SKA3 was found to be overexpressed in LSCC, and its high expression was associated with tumor progression and a poor prognosis. Rescue experiments demonstrated that miR-1207-5p inhibited the malignant phenotypes of LSCC via SKA3. Furthermore, miR-1207-5p upregulation or knockdown of SKA3 inhibited the epithelial-mesenchymal transition (EMT). Collectively, miR-1207-5p inhibited LSCC malignant progression by downregulating SKA3 and preventing EMT. These findings provide new insights into the mechanism of LSCC progression, as well as new potential biomarkers and therapeutic targets for LSCC diagnosis and treatment.

Anticancer Effects and Mechanisms of OSW-1 Isolated From Ornithogalum saundersiae: A Review

For centuries, cancer has been a lingering dark cloud floating on people's heads. With rapid population growth and aging worldwide, cancer incidence and mortality are growing rapidly. Despite major advances in oncotherapy including surgery, radiation and chemical therapy, as well as immunotherapy and targeted therapy, cancer is expected be the leading cause of premature death in this century. Nowadays, natural compounds with potential anticancer effects have become an indispensable natural treasure for discovering clinically useful agents and made remarkable achievements in cancer chemotherapy. In this regards, OSW-1, which was isolated from the bulbs of Ornithogalum saundersiae in 1992, has exhibited powerful anticancer activities in various cancers. However, after almost three decades, OSW-1 is still far from becoming a real anticancer agent for its anticancer mechanisms remain unclear. Therefore, in this review we summarize the available evidence on the anticancer effects and mechanisms of OSW-1 in vitro and in vivo, and some insights for researchers who are interested in OSW-1 as a potential anticancer drug. We conclude that OSW-1 is a potential candidate for anticancer drugs and deserves further study.

Autophagic secretion of HMGB1 from cancer-associated fibroblasts promotes metastatic potential of non-small cell lung cancer cells via NFκB signaling

Tumor progression requires the communication between tumor cells and tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) are major components of stromal cells. CAFs contribute to metastasis process through direct or indirect interaction with tumor cells; however, the underlying mechanism is largely unknown. Here, we reported that autophagy was upregulated in lung cancer-associated CAFs compared to normal fibroblasts (NFs), and autophagy was responsible for the promoting effect of CAFs on non-small cell lung cancer (NSCLC) cell migration and invasion. Inhibition of CAFs autophagy attenuated their regulation on epithelial–mesenchymal transition (EMT) and metastasis-related genes of NSCLC cells. High mobility group box 1 (HMGB1) secreted by CAFs mediated CAFs’ effect on lung cancer cell invasion, demonstrated by using recombinant HMGB1, HMGB1 neutralizing antibody, and HMGB1 inhibitor glycyrrhizin (GA). Importantly, the autophagy blockade of CAFs revealed that HMGB1 release was dependent on autophagy. We also found HMGB1 was responsible, at least in part, for autophagy activation of CAFs, suggesting CAFs remain active through an autocrine HMGB1 loop. Further study demonstrated that HMGB1 facilitated lung cancer cell invasion by activating the NFκB pathway. In a mouse xenograft model, the autophagy specific inhibitor chloroquine abolished the stimulating effect of CAFs on tumor growth. These results elucidated an oncogenic function for secretory autophagy in lung cancer-associated CAFs that promotes metastasis potential, and suggested HMGB1 as a novel therapeutic target.

KLK8 promotes the proliferation and metastasis of colorectal cancer via the activation of EMT associated with PAR1

Kallikrein-related peptidase 8 (KLK8) acts as an oncogene or anti-oncogene in various tumours, and the abnormal expression of KLK8 is involved in the carcinogenesis of several tumours. However, the role of KLK8 in colorectal cancer (CRC) and the underlying mechanism remain largely unclear. In this study, the carcinogenic effect of KLK8 was determined via CCK-8 and colony formation assays in vitro and a xenograft model in nude mice in vivo. The metastasis-promoting effect of KLK8 was investigated with transwell migration and invasion assays and wound-healing assay in vitro and a metastasis model in nude mice in vivo. Bioinformatics analyses and mechanistic experiments were conducted to elucidate the molecular mechanism. Herein, we reported that KLK8 had a promotive effect on the proliferation, migration and invasion of RKO and SW480 cells. Epithelial-mesenchymal transition (EMT) played an important role in the promotive effects of KLK8 on CRC. In addition, protease-activated receptor-1 (PAR-1) antagonist SCH79797 but not protease-activated receptor-2 (PAR-2) antagonist FSLLRY-NH2 attenuated the proliferation, migration and invasion of KLK8-upregulated RKO and SW480 cells. PAR-1 antagonist SCH79797 reduced the tumour volume of xenograft model and decreased the metastatic nodules in the livers of metastasis model. Furthermore, SCH79797 could reverse the positive impact of KLK8 on the EMT process in CRC both in vitro and in vivo. Taken together, these findings demonstrated for the first time that KLK8 promoted EMT and CRC progression, and this effect might be, at least partly mediated by PAR1-dependent pathway.

APMAP Promotes Epithelial-Mesenchymal Transition and Metastasis of Cervical Cancer Cells by Activating the Wnt/β-catenin Pathway

Cervical cancer is a malignant tumor of the female reproductive system. At present, its occurrence, development and transfer mechanism are not entirely clear. APMAP (Adipocyte Plasma Membrane Associated Protein) is a glycosyl type II transmembrane protein that is mainly distributed in the plasma membrane and endoplasmic reticulum of adipocytes. APMAP has been reported to be involved in lipid transport and can induce epithelial-mesenchymal transition of prostate cancer and the liver metastasis of colorectal cancer. However, the role of APMAP in cervical cancer is still unknown. We analyzed the expression and prognosis of APMAP using data in both the GEO and the TCGA databases. We analyzed the function of APMAP using Transwell, wound healing assay and flow cytometry, and assessed the main mechanisms of APMAP by RT-PCR and Western blotting. We found that APMAP was highly expressed in cervical cancer tissues, and patients with high expression had poor prognosis. The functional in vitro experiments demonstrated that APMAP knockdown significantly inhibited the migration ability of cervical cancer cells, but had little effect on cell apoptosis. Mechanically, APMAP promotes cervical cancer cell migration and epithelial-mesenchymal transition by activating the Wnt/β-catenin pathway. Overall, APMAP is a potential prognostic marker as well as a therapeutic target of cervical cancer.

Dihydromyricetin Inhibits Tumor Growth and Epithelial-Mesenchymal Transition through regulating miR-455-3p in Cholangiocarcinoma

Cholangiocarcinoma (CCA) leads to poor prognosis due to high aggressiveness and common chemoresistance. Dihydromyricetin (DMY), the main bioactive compound isolated from Ampelopsis grossedentata, exhibits broad anti-tumor effects. This study aimed to investigate the inhibitory effect of DMY on CCA tumor growth and epithelial-mesenchymal transition (EMT) and its underlying mechanism in CCA. DMY treatment significantly inhibited cell proliferation and EMT in CCA cell lines. The expression of ZEB1 and vimentin were down-regulated, while the level of E-cadherin was increased after DMY treatment. By analyzing the TCGA dataset, we found that miR-455 expression was significantly downregulated, while the level of ZEB1 was up-regulated in human CCA tumor tissues compared to normal samples. Mechanistic studies showed that ZEB1 was a direct target of miR-455-3p in CCA. Moreover, DMY treatment potently increased miR-455-3p expression and inhibited ZEB1 expression. Inhibition of miR-455-3p expression abolished DMY's inhibitory effects on tumor growth and EMT in both CCA cells and cell-engrafted nude mice. Finally, DMY significantly suppressed the expressions of p-PI3K and p-AKT, while silencing miR-455-3p remarkably abrogated the inhibitory effect. In conclusion, DMY suppresses tumor growth and EMT through regulating miR-455-3p in human cholangiocarcinoma, suggesting a potential option for CCA treatment.

miRNA-877-5p inhibits malignant progression of prostate cancer by directly targeting SSFA2

In this study, we aimed to investigate the role of miR-877-5p in the malignant phenotypes of prostate cancer (PCa) cells and its underlying mechanism. RT-qPCR analysis was performed to examine the expression of miR- 877-5p and sperm-specific antigen 2 (SSFA2) in PCa tissues and cells. Cell counting kit-8 (CCK-8) assay, 5- ethynyl-20-deoxyuridine (EdU) assay, flow cytometry, wound-healing assay, and Transwell invasion assay were performed to determine the functional roles of miR-877-5p in PCa cells. The association of miR-877-5p with SSFA2 was determined by luciferase reporter and RNA pull-down assays. In this study, we found that the expression level of miR-877-5p was decreased in PCa tissues and cells. Functionally, overexpression of miR- 877-5p exerted tumor suppressor properties in PCa cells. Mechanistically, SSFA2 was identified as a target gene of miR-877-5p, while overexpression of SSFA2 could abrogate the anti-tumor effects of miR-877-5p in PCa cells. These findings demonstrated that miR-877-5p/SSFA2 axis functioned as a potential target for PCa treatment.

HIST1H2BN induced cell proliferation and EMT phenotype in prostate cancer via NF-κB signal pathway

BACKGROUND

The potential role of HIST1H2BN in prostate cancer remains unclear.

OBJECTIVE

To evaluate the carcinogenic role of HIST1H2BN in prostate cancer.

METHODS

The expression of HIST1H2BN in prostate cancer was analyzed using TCGA database and clinical samples. The roles and mechanisms of HIST1H2BN were investigated in DU145 and PC3 cells.

RESULTS

HIST1H2BN was significantly upregulated in prostate cancer. HIST1H2BN knockdown inhibited cell proliferation, migration and EMT phenotype in prostate cancer cells. Downregulating HIST1H2BN diminished the expression and binding activity of NF-κB p65, then influenced the expression of MMP2 and MMP9. CONCLUSION : This is the first study to elaborate a HIST1H2BN-NF-κB-EMT regulatory axis in oncogenesis, indicating that HIST1H2BN might be potential therapeutic target for prostate cancer.

Stress-Induced Polyploid Giant Cancer Cells: Unique Way of Formation and Non-Negligible Characteristics

Polyploidy is a conserved mechanism in cell development and stress responses. Multiple stresses of treatment, including radiation and chemotherapy drugs, can induce the polyploidization of tumor cells. Through endoreplication or cell fusion, diploid tumor cells convert into giant tumor cells with single large nuclei or multiple small nucleuses. Some of the stress-induced colossal cells, which were previously thought to be senescent and have no ability to proliferate, can escape the fate of death by a special way. They can remain alive at least before producing progeny cells through asymmetric cell division, a depolyploidization way named neosis. Those large and danger cells are recognized as polyploid giant cancer cells (PGCCs). Such cells are under suspicion of being highly related to tumor recurrence and metastasis after treatment and can bring new targets for cancer therapy. However, differences in formation mechanisms between PGCCs and well-accepted polyploid cancer cells are largely unknown. In this review, the methods used in different studies to induce polyploid cells are summarized, and several mechanisms of polyploidization are demonstrated. Besides, we discuss some characteristics related to the poor prognosis caused by PGCCs in order to provide readers with a more comprehensive understanding of these huge cells.

MiR-613 inhibits the proliferation, migration, and invasion of papillary thyroid carcinoma cells by directly targeting TAGLN2

Background

Papillary thyroid carcinoma (PTC), with a rapidly increasing incidence, is the most prevalent malignant cancer of the thyroid. However, its pathogenesis is unclear and its specific clinical indicators have not yet been identified. There is increasing evidence that microRNAs (miRNAs) play important roles in tumor occurrence and progression. Specifically, miR-613 participates in the regulation of tumor development in various cancers; however, its effects and mechanisms of action in PTC are still unclear. Therefore, in this study, we investigated the expression and function of miR-613 in PTC.

Methods

qRT-PCR was used to determine miR-613 expression in 107 pairs of PTC and adjacent-normal tissues as well as in PTC cell lines and to detect TAGLN2 mRNA expression in PTC tissues and adjacent normal tissues. Western blot analysis was performed to identify TAGLN2 and epithelial–mesenchymal transition (EMT) biomarkers. The effects of miR-613 on PTC progression were evaluated by performing MTS, wound-healing, and Transwell assays in vitro. Luciferase reporter assays were also performed to validate the target of miR-613.

Results

In PTC, miR-613 was significantly downregulated and its low expression level was associated with cervical lymph node metastasis. However, its overexpression significantly suppressed PTC cell proliferation, migration, and invasion and inhibited EMT. TAGLN2 was identified as a target of miR-613, which also significantly inhibited the expression of TAGLN2. Further, the restoration of TAGLN2 expression attenuated the inhibitory effects of miR-613 on PTC cell proliferation and metastasis.

Conclusion

Our findings demonstrated that miR-613 can suppress the progression of PTC cells by targeting TAGLN2, indicating that miR-613 plays the role of a tumor suppressor in PTC. Overall, these results suggest that the upregulation of miR-613 is a promising therapeutic strategy for PTC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02083-8.

Mitofusin-2 Promotes the Epithelial-Mesenchymal Transition-Induced Cervical Cancer Progression

High expression of mitofusin-2 (MFN2), a mitochondrial fusion protein, has been frequently associated with poor prognosis of patients with cervical cancer. Here, we aimed to identify the function of MFN2 in cervical cancer to understand its influence on disease prognosis. To this end, from cervical adenocarcinoma, we performed an MTT assay and quantitative RT-PCR (qRT-PCR) analysis to assess the effects of MFN2 on the proliferation and of HeLa cells. Then, colony-formation ability and tumorigenesis were evaluated using a tumor xenograft mouse model. The migration ability related to MFN2 was also measured using a wound healing assay. Consequently, epithelial-mesenchymal transition (EMT) of MFN2-knockdowned HeLa cells originating from adenocarcinoma. markers related to MFN2 were assessed by qRT-PCR. Clinical data were analyzed using cBioPortal and The Cancer Genome Atlas. We found that MFN2 knockdown reduced the proliferation, colony formation ability, migration, and in vivo tumorigenesis of HeLa cells. Primarily, migration of MFN2-knockdowned HeLa cells decreased through the suppression of EMT. Thus, we concluded that MFN2 facilitates cancer progression and in vivo tumorigenesis in HeLa cells. These findings suggest that MFN2 could be a novel target to regulate the EMT program and tumorigenic potential in HeLa cells and might serve as a therapeutic target for cervical cancer. Taken together, this study is expected to contribute to the treatment of patients with cervical cancer.

A 3D physio-mimetic interpenetrating network-based platform to decode the pro and anti-tumorigenic properties of cancer-associated fibroblasts

Three-dimensional (3D) biomaterials with physiologically relevant and experimentally tractable biomechanical features are important platforms to advance our understanding of the influence of tissue mechanics in disease progression. Herein, an interpenetrating network (IPN) of collagen and alginate 3D culture system with tunable extracellular microstructure and mechanics is exploited as a tumor stroma proxy to study phenotypic plasticity of colorectal cancer-associated fibroblasts (CAF). In combination with Next Generation Sequencing (NGS) data analysis, we demonstrated that tuning the storage modulus of the IPN hydrogel between 49 and 419 Pa can trigger a reversible switch between an inflammatory (i-state, α-SMA^lowIL-6^high) and myofibroblastic (m-state, α-SMA^highIL-6^low) state in CAF that is dependent on the polymer network confinement effect and ROS-HIF1-α mechanotransduction signaling axis. Secretome from m-state CAF upregulated several epithelial-mesenchymal-transition (EMT) transcripts and induced robust scattering in DLD-1, HCT116, and SW480 human colorectal adenocarcinoma, while the EMT-inducing capacity is muted in i-state CAF, suggestive of an anti-tumorigenic role. Our findings were further validated through Gene Expression Profiling Interactive Analysis (GEPIA), which showed that cytokines secreted at higher levels by i-state CAF are correlated (p < 0.05) with good overall colorectal cancer patient survival. Therefore, 3D network density and spatial cellular confinement are critical biophysical determinants that can profoundly influence CAF states, paracrine signaling, and EMT-inducing potential. STATEMENT OF SIGNIFICANCE: The communication between cancer cells and cancer-associated fibroblasts (CAF) contributes to tumor metastasis. CAF represent a diverse population of cellular subsets that can either promote or restrain tumor progression. However, the origin and cause of CAF heterogeneity remain elusive, limiting CAF-directed therapies for clinical use. We studied the dynamic phenotypes of CAF using a 3D physio-mimetic culture platform consisting of an interpenetrating collagen-alginate network. Combined with transcriptomic stratification and correlative analysis using cancer patient dataset, we showed phenotypic interconversion between inflammatory and myofibroblastic states, with anti- and pro-tumorigenic functions, in human colorectal CAF. This multidisciplinary study reveals the functional diversity of colorectal CAF caused by biophysical cues. The finding will influence the development of new CAF biomarkers and cancer therapies.

Dynamic EMT: a multi-tool for tumor progression

The process of epithelial-mesenchymal transition (EMT) is fundamental for embryonic morphogenesis. Cells undergoing it lose epithelial characteristics and integrity, acquire mesenchymal features, and become motile. In cancer, this program is hijacked to confer essential changes in morphology and motility that fuel invasion. In addition, EMT is increasingly understood to orchestrate a large variety of complementary cancer features, such as tumor cell stemness, tumorigenicity, resistance to therapy and adaptation to changes in the microenvironment. In this review, we summarize recent findings related to these various classical and non-classical functions, and introduce EMT as a true tumorigenic multi-tool, involved in many aspects of cancer. We suggest that therapeutic targeting of the EMT process will-if acknowledging these complexities-be a possibility to concurrently interfere with tumor progression on many levels.

The Significance of Exosomes in Pathogenesis, Diagnosis, and Treatment of Esophageal Cancer

Esophageal cancer is one of the most common malignancy in China with high mortality. Understanding pathogenesis and identifying early diagnosis biomarkers can significantly improve the prognosis of patients with esophageal cancer. Exosomes are small vesicular structures containing a variety of components (including DNA, RNA, and proteins) mediating cell-to-cell material exchange and signal communication. Growing evidences have shown that exosomes and its components are involved in growth, metastasis and angiogenesis in cancer, and could also be used as diagnostic and prognostic markers. In this review, we summarized recent progress to elucidate the significance of exosomes in the esophageal cancer progression, microenvironment remodeling, therapeutic resistance, and immunosuppression. We also discuss the utility of exosomes as diagnostic and prognostic biomarkers and therapeutic tool in esophageal cancer.

Protein tyrosine phosphatase, receptor type B is a potential biomarker and facilitates cervical cancer metastasis via epithelial-mesenchymal transition

Cervical cancer (CC) is one of the most common malignant tumors. This study analyzed the impact of protein tyrosine phosphatase, receptor type B (PTPRB) on malignant behavior of CC and explored its possible molecular mechanism. RT-PCR, western blot and Immunohistochemistry were applied to examine the expression of PTPRB in CC specimens and cells. Aberrant PTPRB expression in CC and survival outcomes were constructed using The Cancer Genome Atlas (TCGA) database and tissue microarray cervical squamous cell carcinoma cohort. Cultured human CC cells were assayed for viability, apoptosis, migration, and invasion in vitro and in vivo. Kyoto Encyclopedia of Genes and Genomes (KEGG) assays and gene set enrichment analysis (GSEA) assays were used to delve into PTPRB-related pathways using TCGA datasets. The levels of proteins associated with the epithelial-mesenchymal transition (EMT) pathway and modulated by PTPRB were examined through Western blot. We found that the levels of PTPRB in CC tissues and cells were distinctly up-regulated. PTPRB was also an unfavorable prognostic factor for CC patients. Functionally, PTPRB knockdown exhibits tumor-suppressive function via reducing cell proliferation and metastasis and inducing cell apoptosis. KEGG assays and GSEA assays suggested PTPRB overexpression was associated with several tumor-related pathways. The results of Western blot assays suggested that N-cadherin was decreased in the PTPRB-knockdown CC cells, while E-cadherin was increased. Overall, PTPRB is highly expressed in CC and can effectively enhance the proliferation, metastasis and EMT process of tumor cells. PTPRB is expected to be a therapeutic target for CC.

The Recruitment of Neutrophils to the Tumor Microenvironment Is Regulated by Multiple Mediators

Neutrophils sense and migrate towards chemotactic factors released at sites of infection/inflammation and contain the affected area using a variety of effector mechanisms. Aside from these established immune defense functions, neutrophils are emerging as one of the key tumor-infiltrating immune cells that influence cancer progression and metastasis. Neutrophil recruitment to the tumor microenvironment (TME) is mediated by multiple mediators including cytokines, chemokines, lipids, and growth factors that are secreted from cancer cells and cancer-associated stromal cells. However, the molecular mechanisms that underlie the expression and secretion of the different mediators from cancer cells and how neutrophils integrate these signals to reach and invade tumors remain unclear. Here, we discuss the possible role of the epithelial to mesenchymal transition (EMT) program, which is a well-established promoter of malignant potential in cancer, in regulating the expression and secretion of these key mediators. We also summarize and review our current understanding of the machineries that potentially control the secretion of the mediators from cancer cells, including the exocytic trafficking pathways, secretory autophagy, and extracellular vesicle-mediated secretion. We further reflect on possible mechanisms by which different mediators collaborate by integrating their signaling network, and particularly focus on TGF-β, a cytokine that is highly expressed in invasive tumors, and CXCR2 ligands, which are crucial neutrophil recruiting chemokines. Finally, we highlight gaps in the field and the need to expand current knowledge of the secretory machineries and cross-talks among mediators to develop novel neutrophil targeting strategies as effective therapeutic options in the treatment of cancer.

Cancer chemoprevention through Frizzled receptors and EMT

Frizzled (FZD) transmembrane receptors are well known for their role in β-catenin signaling and development and now understanding of their role in the context of cancer is growing. FZDs are often associated with the process of epithelial to mesenchymal transition (EMT) through β-catenin, but some also influence EMT through non-canonical pathways. With ten different FZDs, there is a wide range of activity from oncogenic to tumor suppressive depending on the tissue context. Alterations in FZD signaling can occur during development of premalignant lesions, supporting their potential as targets of chemoprevention agents. Agonizing or antagonizing FZD activity may affect EMT, which is a key process in lesion progression often targeted by chemoprevention agents. Recent studies identified a specific FZD as important for activity of an EMT inhibiting chemopreventive agent and other studies have highlighted the previously unrecognized potential for targeting small molecules to FZD receptors. This work demonstrates the value of investigating FZDs in chemoprevention and here we provide a review of FZDs in cancer EMT and their potential as chemoprevention targets.

ELTD1 Promotes Gastric Cancer Cell Proliferation, Invasion and Epithelial-Mesenchymal Transition Through MAPK/ERK Signaling by Regulating CSK

Purpose

Patients with gastric cancer (GC) often die from metastasis. However, the exact molecular mechanism underlying GC metastasis is complicated and still remains elusive. Epidermal growth factor, latrophilin and seven-transmembrane domain-containing 1 (ELTD1), has been reported to be involved in cancer metastasis, but its role in GC is still missing.

Patients and Methods

We first analyzed the expression of ELTD1 in GC using public databases (TCGA, Oncomine, and GEO) and our clinical samples. The functions of ELTD1 in GC proliferation, invasion and metastasis were determined by in vitro and in vivo experiments. The functional mechanism of ETLD1 in GC was also investigated. Finally, the association between ELTD1 expression and the overall survival of GC patients was analyzed using public databases.

Results

ELTD1 is significantly upregulated in GC tissues. Knockdown of ELTD1 inhibits GC cell proliferation, migration and invasion in vitro as well as tumor growth and metastasis in vivo, while ELTD1 overexpression obtains opposite results. Moreover, ELTD1 could promote epithelial to mesenchymal transition (EMT) in GC. Mechanistically, ELTD1 exerts its tumor-promoting effect by activating MAPK/ERK signaling. Subsequent studies demonstrated that ELTD1 could interact with C-terminal Src kinase (CSK) and inhibit its expression, which finally lead to MAPK/ERK activation. Data from TGCA and GEO both revealed that GC patients with high ELTD1 expression had poorer prognosis and the combination of ELTD1 with CSK showed better predictive performance.

Conclusion

ELTD1 plays an oncogene role in GC through MAPK/ERK signaling via inhibiting CSK, which may be a useful prognostic predictor and potential therapeutic target for GC.

Identification of abnormally high expression of POGZ as a new biomarker associated with a poor prognosis in osteosarcoma

Osteosarcoma (OS) is the most prevalent malignant bone tumor in children and young adults. There is an urgent need for a novel biomarker related to the prognosis of OS. We performed a meta-analysis incorporating six independent datasets and performed a survival analysis with one independent dataset GSE21257 in the GEO database for gene screening. The results revealed that one potential biomarker related to OS survival, POGZ was the most significantly upregulated gene. We also verified that the POGZ was overexpressed in clinical samples. The survival analysis revealed that POGZ is associated with a poor prognosis in OS. Moreover, flow cytometry analysis of isolated OS cells demonstrated that OS cells were arrested in the G1 phase after POGZ knockdown. The RNA-seq results indicated that POGZ was co-expressed with CCNE1 and CCNB1. Pathway analysis showed that genes associated with high expression levels of POGZ were related to the cell cycle pathway. A cell model was constructed to detect the effects of POGZ. After POGZ knockdown, OS cell proliferation, invasion and migration were all decreased. Therefore, POGZ is an important gene for evaluating the prognosis of OS patients and is a potential therapeutic target.

Combination therapy with miR34a and doxorubicin synergistically inhibits Dox-resistant breast cancer progression via down-regulation of Snail through suppressing Notch/NF-κB and RAS/RAF/MEK/ERK signaling pathway

Resistance to breast cancer (BCa) chemotherapy severely hampers the patient's prognosis. MicroRNAs provide a potential therapeutic prospect for BCa. In this study, the reversal function of microRNA34a (miR34a) on doxorubicin (Dox) resistance of BCa and the possible mechanism was investigated. We found that the relative level of miR34a was significantly decreased in Dox-resistant breast cancer cell MCF-7 (MCF-7/A) compared with Dox-sensitive MCF-7 cells. Transfection with miR34a significantly suppressed the invasion, migration, adhesion of MCF-7/A cells without inhibiting their growth obviously. The combination of miR34a and Dox could significantly inhibit the proliferation, migration, invasion and induce the apoptosis of MCF-7/A cells. The synergistic effect of this combination on resistant MCF-7/A cells has no obvious relation with the expressions of classical drug-resistant proteins P-GP, MRP and GST-π, while closely related with the down-regulation on TOP2A and BCRP. Moreover, we found both protein and mRNA expression of Snail were significantly up-regulated in MCF-7/A cells in comparison with MCF-7 cells. Transfection with small interfering RNA (siRNA) of Snail could inhibit the invasion, migration and adhesion of drug-resistant MCF-7/A cells, while high-expression of Snail could remarkably promote the invasion, migration and adhesion of MCF-7 cells, which might be related with regulation of N-cadherin and E-cadherin. Transfection with miR34a in MCF-7/A cells induced a decrease of Snail expression. The potential binding sites of miR34a with 3' UTR of Snail were predicted by miRDB target prediction software, which was confirmed by luciferase reporter gene method. Results showed that the relative activity of luciferase was reduced in MCF-7/A cells after co-transfection of miR34a and wild type (wt)-Snail, while did not change by co-transfection with miR34a and 3' UTR mutant type (mut) Snail. Combination of miR34a and Dox induced a stronger decrease of Snail in MCF-7/A cells in comparison to miR34a or Dox treatment alone. What' more, for the first time, we also found miR34a combined with Dox could obviously inhibit the expression of Snail through suppressing Notch/NF-κB and RAS/RAF/MEK/ERK pathway in MCF-7/A cells. In vivo study indicated that combination of miR34a and Dox significantly slowed down tumor growth in MCF-7/A nude mouse xenograft model compared with Dox alone, which was manifested by the down-regulation of Snail and pro-apoptosis effect in tumor xenografts. These results together underline the relevance of miR34a-driven regulation of Snail in drug resistance and co-administration of miR34a and Dox may produce an effective therapy outcome in the future in clinic.