CXCL1/GROα increases cell migration and invasion of prostate cancer by decreasing fibulin-1 expression through NF-κB/HDAC1 epigenetic regulation

Association of ulcerative colitis and acute gastroenteritis with prostate specific antigen: results from National Health and Nutrition Examination Survey from (2009 to 2010) and Mendelian randomization analyses

Background

An increasing number of studies have demonstrated that gastrointestinal inflammation may increase prostate cancer risk and raise the prostate-specific antigen (PSA) level. However, the association between ulcerative colitis (UC) and acute gastroenteritis (AGE) with PSA remains unclear and complicated. Herein, we evaluated the relationship between UC and AGE with PSA concentration using the National Health and Nutrition Examination Survey (NHANES) database and Mendelian randomization (MR) analyses.

Materials and methods

A total of 1,234 participants fit into the study after conducting the screening based on the NHANES survey conducted from 2009 to 2010. UC and AGE were the independent variables, and PSA was the dependent variable. Weighted multiple linear regressions were utilized to estimate the association of UC and AGE with PSA concentration. To detect the causal relationship between UC and AGE with PSA, a two-sample Mendelian randomized analysis was conducted.

Results

After controlling for all covariates, PSA (log2 transform) concentrations in the UC group were increased by 0.64 (0.07, 1.21). AGE was not independently associated with PSA levels after adjusting potential confounders. In patients with coronary artery disease, AGE promotes elevated PSA (log2 transform) concentrations (β = 1.20, 95% CI: 0.21-2.20, p < 0.001). Moreover, an IVW MR analysis indicated that genetically predicted UC was associated with increased PSA, and that AGE was not associated with PSA.

Conclusion

This study indicated that a positive causal association exists between UC and the PSA level. However, there is no evidence to support the relationship between AGE and the PSA level.

Mycoplasma hyorhinis infection promotes TNF-α signaling and SMAC mimetic-mediated apoptosis in human prostate cancer

Growing evidence suggests an association between Mycoplasma infections and the development and progression of prostate cancer (PCa). In this study, we report that chronic and persistent M. hyorhinis infection induced robust TNF-α secretion from PCa cells. TNF-α secreted from M. hyorhinis-infected PCa cells subsequently led to activation of the NF-κB pathway. Chronic M. hyorhinis infection induced gene expression of pro-inflammatory cytokines and chemokines in a NF-κB-dependent manner and promoted cell proliferation, migration, and invasion in PCa cells. The elimination of M. hyorhinis in PCa cells significantly blocked TNF-α secretion, gene expression of cytokines and chemokines, migration, and invasion in PCa cells, suggesting M. hyorhinis-induced TNF-α plays an important role to promote malignant transformation of PCa. Furthermore, second mitochondria-derived activator of caspases (SMAC) mimetics potentiated caspase activation and cell death in M. hyorhinis-infected PCa by antagonizing inhibitor of apoptosis proteins (IAPs) activity. Tissue microarray analysis indicated that TNF-α is co-expressed in M. hyorhinis-infected human patient tissues. Findings from this study advance our understanding of the mycoplasma-oncogenesis process and suggest the potential for new approaches for preventions, diagnosis, and therapeutic approaches against prostate cancers.

Obesity and prostate cancer - microenvironmental roles of adipose tissue

Obesity is known to have important roles in driving prostate cancer aggressiveness and increased mortality. Multiple mechanisms have been postulated for these clinical observations, including effects of diet and lifestyle, systemic changes in energy balance and hormonal regulation and activation of signalling by growth factors and cytokines and other components of the immune system. Over the past decade, research on obesity has shifted towards investigating the role of peri-prostatic white adipose tissue as an important source of locally produced factors that stimulate prostate cancer progression. Cells that comprise white adipose tissue, the adipocytes and their progenitor adipose stromal cells (ASCs), which proliferate to accommodate white adipose tissue expansion in obesity, have been identified as important drivers of obesity-associated cancer progression. Accumulating evidence suggests that adipocytes are a source of lipids that are used by adjacent prostate cancer cells. However, results of preclinical studies indicate that ASCs promote tumour growth by remodelling extracellular matrix and supporting neovascularization, contributing to the recruitment of immunosuppressive cells, and inducing epithelial-mesenchymal transition through paracrine signalling. Because epithelial-mesenchymal transition is associated with cancer chemotherapy resistance and metastasis, ASCs are considered to be potential targets of therapies that could be developed to suppress cancer aggressiveness in patients with obesity.

Intratumor Fusobacterium nucleatum promotes the progression of pancreatic cancer via the CXCL1-CXCR2 axis

Intratumor bacteria modify the tumor immune microenvironment and influence outcomes of various tumors. Periodontal pathogen Fusobacterium nucleatum has been detected in pancreatic cancer tissues and is associated with poor prognosis. However, it remains unclear how F. nucleatum affects pancreatic cancer. Here, we compared clinical features with F. nucleatum colonization in pancreatic cancer tissues. F. nucleatum was detected in 15.5% (13/84) of pancreatic cancer patients. The tumor size was significantly larger in the F. nucleatum-positive group than in the negative group. To clarify the biological effect of intratumor F. nucleatum on pancreatic cancer progression, we performed migration/invasion assays and cytokine array analysis of cancer cells cocultured with F. nucleatum. F. nucleatum promoted CXCL1 secretion from pancreatic cancer cells, leading to cancer progression through autocrine signaling. Intratumor F. nucleatum suppressed tumor-infiltrating CD8+ T cells by recruiting myeloid-derived suppressor cells (MDSCs) to the tumor in an F. nucleatum-injected subcutaneous pancreatic cancer mouse model, resulting in tumor progression. Furthermore, tumor growth accelerated by F. nucleatum was suppressed by MDSC depletion or cytokine inhibitors. Intratumor F. nucleatum promoted pancreatic cancer progression through autocrine and paracrine mechanisms of the CXCL1-CXCR2 axis. Blockade of the CXCL1-CXCR2 axis may be a novel therapeutic approach for patients with intratumor F. nucleatum-positive pancreatic cancer.

The Significance of CXCL1 and CXCR1 as Potential Biomarkers of Colorectal Cancer

The CXCL1/CXCR2 and CXCL8-CXCR1/CXCR2 axes are under intensive investigation as they appear to regulate the progression and invasion of colorectal cancer (CRC). Growing evidence demonstrates the elevated expression of these proteins in CRC. However, a majority of relevant studies have been performed on CRC tissues using immunohistochemical techniques. Our study is the first to evaluate the diagnostic significance of serum CXCL1 and CXCR1 levels in CRC patients in comparison to well-established tumor markers, such as the carcinoembryonic antigen (CEA), and markers of inflammation, such as C-reactive protein (CRP). Thus, the aim of our study was to assess whether circulating serum levels of CXCL1 and CXCR1 might be candidates for novel biomarkers in the diagnosis and progression of CRC. The study was performed on 76 subjects, including patients with CRC and healthy volunteers as a control group. Serum concentrations of CXCL1, CXCR1, and the classical tumor marker (CEA) were measured using immunoenzyme assays, while CRP levels were assessed with the immunoturbidimetric method. Serum CXCL1 levels were statistically significantly increased in CRC patients when compared to healthy subjects, and similar results were found for CEA and CRP levels. The percentage of elevated concentrations of CXCL1 and CXCR1 was higher than that of the classical tumor biomarker and increased in the combined measurement of these proteins with CEA. In addition, among all proteins tested, serum CXCL1 seems to be the best indicator in the differentiation between CRC patients with nodal involvement and patients without the presence of lymph node metastasis. Our preliminary results indicate the role of serum CXCL1 and CXCR1 in the diagnosis of CRC, particularly in the combined measurement with CEA.

Immunological protein profiling of first-episode psychosis patients identifies CSF and blood biomarkers correlating with disease severity

BACKGROUND AND HYPOTHESIS

Immune activation is suggested to play an important role in psychosis. In this study, a large number of immune-related proteins were analyzed to obtain a more comprehensive picture of immune aberrations in schizophrenia.

STUDY DESIGN

Ninety-two immune markers were analyzed by the Olink Protein Extension Assay (Inflammatory Panel) in plasma and cerebrospinal fluid (CSF) from 77 first-episode psychosis (FEP) patients (of which 43 later received the diagnosis of schizophrenia) and 56 healthy controls, all recruited from the Karolinska Schizophrenia Project (KaSP), Stockholm, Sweden.

STUDY RESULTS

Differential analysis showed that 12 of 92 inflammatory proteins were significantly higher in the plasma of FEP patients (n = 77) than in controls, and several proteins were positively correlated with disease severity. Patients from the same cohort diagnosed with schizophrenia (n = 43), showed significantly higher levels of 15 plasma proteins compared to controls whereas those not receiving this diagnosis showed no significant differences. The presently used OLINK inflammatory panel allowed the detection of only 47 CSF proteins of which only CD5 differed between patients and controls.

CONCLUSIONS

The levels of several peripheral immune markers, particularly those interfering with WNT/β-catenin signaling, were significantly higher in patients with FEP than in healthy controls and associated with illness severity.

Involvement in Tumorigenesis and Clinical Significance of CXCL1 in Reproductive Cancers: Breast Cancer, Cervical Cancer, Endometrial Cancer, Ovarian Cancer and Prostate Cancer

C-X-C motif chemokine ligand 1 (CXCL1) is a member of the CXC chemokine subfamily and a ligand for CXCR2. Its main function in the immune system is the chemoattraction of neutrophils. However, there is a lack of comprehensive reviews summarizing the significance of CXCL1 in cancer processes. To fill this gap, this work describes the clinical significance and participation of CXCL1 in cancer processes in the most important reproductive cancers: breast cancer, cervical cancer, endometrial cancer, ovarian cancer, and prostate cancer. The focus is on both clinical aspects and the significance of CXCL1 in molecular cancer processes. We describe the association of CXCL1 with clinical features of tumors, including prognosis, ER, PR and HER2 status, and TNM stage. We present the molecular contribution of CXCL1 to chemoresistance and radioresistance in selected tumors and its influence on the proliferation, migration, and invasion of tumor cells. Additionally, we present the impact of CXCL1 on the microenvironment of reproductive cancers, including its effect on angiogenesis, recruitment, and function of cancer-associated cells (macrophages, neutrophils, MDSC, and T_reg). The article concludes by summarizing the significance of introducing drugs targeting CXCL1. This paper also discusses the significance of ACKR1/DARC in reproductive cancers.

Identification of Promising Drug Candidates against Prostate Cancer through Computationally-Driven Drug Repurposing

Prostate cancer (PC) is one of the most common types of cancer in males. Although early stages of PC are generally associated with favorable outcomes, advanced phases of the disease present a significantly poorer prognosis. Moreover, currently available therapeutic options for the treatment of PC are still limited, being mainly focused on androgen deprivation therapies and being characterized by low efficacy in patients. As a consequence, there is a pressing need to identify alternative and more effective therapeutics. In this study, we performed large-scale 2D and 3D similarity analyses between compounds reported in the DrugBank database and ChEMBL molecules with reported anti-proliferative activity on various PC cell lines. The analyses included also the identification of biological targets of ligands with potent activity on PC cells, as well as investigations on the activity annotations and clinical data associated with the more relevant compounds emerging from the ligand-based similarity results. The results led to the prioritization of a set of drugs and/or clinically tested candidates potentially useful in drug repurposing against PC.

CXCL1 confers a survival advantage in Kaposi's sarcoma-associated herpesvirus-infected human endothelial cells through STAT3 phosphorylation

Many cytokines produced by Kaposi's sarcoma-associated herpesvirus (KSHV)-infected cells have been shown to participate in the pathogenesis of KSHV. Determination of the exact role of cytokines in Kaposi's sarcoma (KS) pathogenesis is limited, however, by the difficulty to manipulate the target genes in human endothelial cells. In this study, we sought to elucidate the role of cytokines in KSHV-infected human immortalized endothelial cell line (HuARLT cells) by knockout (KO) of the corresponding target genes using the CRISPR/Cas9 system. The cytokine production profile of KSHV-infected HuARLT cells was analyzed using a protein array, and several cytokines were found to be highly upregulated following KSHV infection. This study focused on CXCL1, which was investigated by knocked out in HuARLT cells. KSHV-infected CXCL1 KO cells underwent increased cell death compared to KSHV-infected wild-type (WT) cells and mock-infected CXCL1 KO cells. Lytic replication was not observed in KSHV-infected WT nor CXCL1 KO cells. Phosphorylation of STAT3 was significantly suppressed in KSHV-infected CXCL1 KO cells. Additionally, inhibitors of STAT3 and CXCL1 induced cell death in KSHV-infected endothelial cells. Our results show that CXCL1 production is required for the survival of KSHV-infected endothelial cells, and the CXCL1 to STAT3 phosphorylation signaling pathway may be a therapeutic target for KS.

CXCL1 promotes colon cancer progression through activation of NF-κB/P300 signaling pathway

BACKGROUND

The upregulated expression of CXCL1 has been validated in colorectal cancer patients. As a potential biotherapeutic target for colorectal cancer, the mechanism by which CXCL1 affects the development of colorectal cancer is not clear.

METHODS

Expression data of CXCL1 in colorectal cancer were obtained from the GEO database and verified using the GEPIA database and the TIMER 2.0 database. Knockout and overexpression of CXCL1 in colorectal cancer cells by CRISPR/Cas and "Sleeping Beauty" transposon-mediated gene editing techniques. Cell biological function was demonstrated by CCK-8, transwell chamber and Colony formation assay. RT-qPCR and Western Blot assays measured RNA and protein expression. Protein localization and expression were measured by immunohistochemistry and immunofluorescence.

RESULTS

Bioinformatics analysis showed significant overexpression of CXCL1 in the colorectal cancer tissues compared to normal human tissues, and identified CXCL1 as a potential therapeutic target for colorectal cancer. We demonstrate that CXCL1 promotes the proliferation and migration of colon cancer cells and has a facilitative effect on tumor angiogenesis. Furthermore, CXCL1 elevation promoted the migration of M2-tumor associated macrophages (TAMs) while disrupting the aggregation of CD4+ and CD8+ T cells at tumor sites. Mechanistic studies suggested that CXCL1 activates the NF-κB pathway. In the in vivo colon cancer transplantation tumor model, treatment with the P300 inhibitor C646 significantly inhibited the growth of CXCL1-overexpressing colon cancer.

CONCLUSION

CXCL1 promotes colon cancer development through activation of NF-κB/P300, and that CXCL1-based therapy is a potential novel strategy to prevent colon cancer development.

Tumor-associated macrophages promote resistance of hepatocellular carcinoma cells against sorafenib by activating CXCR2 signaling

BACKGROUND

Sorafenib (SOR) is the first line treatment for advanced hepatocellular carcinoma (HCC), but resistance develops frequently. Tumor-associated macrophages (TAMs) have been reported to affect the progression of HCC. We therefore aimed to study the role of TAMs in promoting SOR resistance.

METHODS

Immunofluorescence staining for the M2 marker CD204 and the cancer stem cell (CSC) markers CD44 and CD133 was performed in paired HCC and adjacent noncancerous tissues and HCC tissues stratified by response of SOR treatment. HCC/U937 coculture system and cytokines were used to induce M2 polarization for studying the effects of M2 TAMs on CSC properties and apoptotic death of HCC cells after SOR treatment.

RESULTS

Higher expression of CD204, CD44, and CD133 was observed in patients with SOR nonresponse (SNR) than in those with SOR response (SR), suggesting that SNR is positively correlated to levels of CSCs and M2 TAMs. After coculture, M2 TAMs could increase the level of CSCs but decrease SOR-induced apoptosis. Incubation of HCC cells with coculture conditioned medium increased the formation of spheres that were resistant to SOR. Furthermore, CXCL1 and CXCL2 were found to be the potential paracrine factors released by M2 TAMs to upregulate SOR resistance in HCC cells. Treatment with CXCL1 and CXCL2 could increase HCC CSC activity but decrease SOR-induced apoptosis by affecting BCL-2 family gene expression. Using pharmacological inhibitors, CXCR2/ERK signaling was found to be critical to CXCL1- and CXCL2-mediated SOR resistance.

CONCLUSION

This study identified CXCL1, CXCL2, and their downstream CXCR2/ERK signaling as potential therapeutic targets to overcome SOR resistance in HCC.

Plasma Levels of CXC Motif Chemokine 1 (CXCL1) and Chemokine 8 (CXCL8) as Diagnostic Biomarkers in Luminal A and B Breast Cancer

Chemokines are involved in the regulation of immune balance and in triggering an immune response. CXCL1 and CXCL8 belong to the ELR-motif-containing group of CXC chemokines, which, in breast cancer (BC), stimulate angiogenesis and increase migration and invasiveness of tumor cells. The aim of this study was to evaluate CXCL1, CXCL8 and comparative marker CA 15-3 plasma concentrations in BC patients with luminal subtypes A and B. The study group consisted of 100 patients with BC, and the control group of 50 subjects with benign breast lesions and 50 healthy women. Chemokines concentrations were determined by ELISA method; CA15-3-by CMIA. Concentrations of CXCL8 and CA15-3 were significantly higher in BC total group and luminal B (for CA15-3 also in luminal A) subtype of BC than in healthy controls and subjects with benign lesions. In the total BC group, the highest SE, PPV and NPV were observed for CXCL8 (70%, 77.78%, 50%, resp.). A combined analysis of tested chemokines with CA 15-3 increased SE and NPV values (96%, 69.23%, resp.). The diagnostic power of the test (measured by area under ROC curve (AUC)) showed the highest value for CXCL8 in the total BC group (0.6410), luminal A (0.6120) and B subgroup of BC (0.6700). For the combined parameter, the AUC was increasing and reached the highest value for CXCL1 + CXCL8 + CA15-3 combination (0.7024). In light of these results, we suggest that CXCL8 could be used as an additional diagnostic marker that would positively influence the diagnostic utility of CA 15-3, especially in luminal B subtype of BC.

Inflammatory bowel disease induces inflammatory and pre-neoplastic changes in the prostate

BACKGROUND

Inflammatory bowel disease (IBD) has been implicated as a risk factor for prostate cancer, however, the mechanism of how IBD leads to prostate tumorigenesis is not known. Here, we investigated whether chronic intestinal inflammation leads to pro-inflammatory changes associated with tumorigenesis in the prostate.

METHODS

Using clinical samples of men with IBD who underwent prostatectomy, we analyzed whether prostate tumors had differences in lymphocyte infiltrate compared to non-IBD controls. In a mouse model of chemically-induced intestinal inflammation, we investigated whether chronic intestinal inflammation could be transferred to the wild-type mouse prostate. In addition, mouse prostates were evaluated for activation of pro-oncogenic signaling and genomic instability.

RESULTS

A higher proportion of men with IBD had T and B lymphocyte infiltration within prostate tumors. Mice with chronic colitis showed significant increases in prostatic CD45 + leukocyte infiltration and elevation of three pro-inflammatory cytokines-TIMP-1, CCL5, and CXCL1 and activation of AKT and NF-kB signaling pathways. Lastly, mice with chronic colitis had greater prostatic oxidative stress/DNA damage, and prostate epithelial cells had undergone cell cycle arrest.

CONCLUSIONS

These data suggest chronic intestinal inflammation is associated with an inflammatory-rich, pro-tumorigenic prostatic phenotype which may explain how gut inflammation fosters prostate cancer development in men with IBD.

The Role of Inflammatory Mediators in Colorectal Cancer Hepatic Metastasis

Colorectal cancer (CRC) is the second leading cause of death in cancer patients in the USA, whereas the major cause of CRC deaths is hepatic metastases. The liver is the most common site of metastasis in patients with CRC due to hepatic portal veins receiving blood from the digestive tract. Understanding the cellular and molecular mechanisms of hepatic metastases is of dire need for the development of potent targeted therapeutics. Immuno-signaling molecules including cytokines and chemokines play a pivotal role in hepatic metastases from CRC. This brief review discusses the involvement of three representative cytokines (TNF-α, IL-6 and IL-1β), a lipid molecule PGE2 and two chemokines (CXCL1 and CXCL2) in the process of CRC liver metastases.

TOPK Affects Autophagy of Skin Squamous Cell Carcinoma by Regulating NF-KB Pathway through HDAC1

Objective

To explore the effect and potential mechanism of T-LAK cell-originated protein kinase (TOPK) on autophagy in cutaneous squamous cell carcinoma (cSCC).

Methods

Human cSCC cancer tissue and paracancerous tissue samples were collected clinically; immunohistochemistry was used to detect the expression of TOPK, nuclear factor κB p65 (NF-κB p65), phosphorylated nuclear factor κB inhibitor α (p-IκBα), Beclin-1, and microtubule-associated protein 1 light chain 3 (LC3) in cSCC tissue; and immunofluorescence was adopted to detect the coexpression of NF-κB p65, p-IκBα, and TOPK in cSCC tissue. After TOPK silencing or overexpression, SCL-1 and A431 cells were treated with PDTC and 3-MA, respectively. RT-qPCR and Western Blot were used to detect the mRNA and protein expressions of histone deacetylase 1 (HDAC1) in TOPK-silenced/overexpressing cells. Western Blot was performed to detect the protein expressions of NF-κB p65, p-p65, IκBα, p-IκBα, Beclin-1, and LC3 in each group. Transwell and scratch healing experiments were used to detect the ability of cells to invade and migrate. The formation of autophagosomes in each group was observed by TEM.

Results

Compared with adjacent tissues, TOPK, NF-κB p65, p-IκBα, Beclin-1, and LC3 were highly expressed in cSCC cancer tissues; TOPK and NF-κB p65 were coexpressed; and TOPK and p-IκBα were expressed in cSCC cancer tissues both increased. The mRNA and protein levels of TOPK in human cSCC cells were significantly higher than those in human normal skin HaCaT cells. After TOPK knockout, the expression of HDAC1, p-IκBα/IκBα, NF-κB p65, p-p65, Beclin-1, LC3II/I proteins, cell invasion, and migration abilities were significantly reduced, and fewer autophagosomes were observed. Treatment with PDTC and 3-MA significantly downregulated NF-κB pathway protein activity and autophagy level and reduced cell migration and invasion ability.

Conclusion

TOPK promotes the malignant progression of cSCC by upregulating HDAC1 to activate the NF-κB pathway and promote autophagy.

Extracellular Vesicles Secreted by Corneal Myofibroblasts Promote Corneal Epithelial Cell Migration

Corneal epithelial wound healing is a multifaceted process that encompasses cell proliferation, migration, and communication from the corneal stroma. Upon corneal injury, bidirectional crosstalk between the epithelium and stroma via extracellular vesicles (EVs) has been reported. However, the mechanisms by which the EVs from human corneal keratocytes (HCKs), fibroblasts (HCFs), and/or myofibroblasts (HCMs) exert their effects on the corneal epithelium remain unclear. In this study, HCK-, HCF-, and HCM-EVs were isolated and characterized, and human corneal epithelial (HCE) cell migration was assessed in a scratch assay following PKH26-labeled HCK-, HCF-, or HCM-EV treatment. HCE cells proliferative and apoptotic activity following EV treatment was assessed. HCF-/HCM-EVs were enriched for CD63, CD81, ITGAV, and THBS1 compared to HCK-EV. All EVs were negative for GM130 and showed minimal differences in biophysical properties. At the proteomic level, we showed HCM-EV with a log >two-fold change in CXCL6, CXCL12, MMP1, and MMP2 expression compared to HCK-/HCF-EVs; these proteins are associated with cellular movement pathways. Upon HCM-EV treatment, HCE cell migration, velocity, and proliferation were significantly increased compared to HCK-/HCF-EVs. This study concludes that the HCM-EV protein cargo influences HCE cell migration and proliferation, and understanding these elements may provide a novel therapeutic avenue for corneal wound healing.

Genetic Study of Chemokine Ligand 1 in Colorectal Carcinoma using Quantitative Real-Time PCR

Background: Carcinoma of colon is one of the prevalence carcinoma in the world and it is the most important cause of death in Western countries. The disease process is multifactorial; with etiology include inflammatory conditions of the digestive tract, environmental liableness and genetic factors. Chemokine Ligand1 was share in several mechanisms such as inflammatory process, chemo attraction, and others. Objective: The current study was conducted to analyze gene expression level of chemokine ligand 1 in colonic carcinoma and to deliberate the participant of it as genetic factors in its evolving and prognosis. Material and method: Chemokine Ligand1 gene expression level was evaluated in formalin-fixed, paraffin embedded tissue blocks that is retrospectively collected from 40 patients (8 women and 32 men) with carcinoma, and 40 patients of normal colonic tissues as control specimen by using Real-Time PCR. Results: The expression of Chemokine ligand 1 gene were established as 12.4112 folds in carcinoma specimen in relation to control tissue (1.3492).  Chemokine ligand 1 genes were found to be over-expressed in advanced stage tumors and elderly patients. Conclusions: Chemokine ligand1 can be considered as a recent biomarker and the possibility to use it as therapeutic target in the treatment of colonic carcinoma.

EMT-mediated regulation of CXCL1/5 for resistance to anti-EGFR therapy in colorectal cancer

The emergence of RAS/RAF mutant clone is the main feature of EGFR inhibitor resistance in KRAS wild-type colon cancer. However, its molecular mechanism is thought to be multifactorial, mainly due to cellular heterogeneity. In order to better understand the resistance mechanism in a single clone level, we successfully isolated nine cells with cetuximab-resistant (CR) clonality from in vitro system. All CR cells harbored either KRAS or BRAF mutations. Characteristically, these cells showed a higher EMT (Epithelial to mesenchymal transition) signature, showing increased EMT markers such as SNAI2. Moreover, the expression level of CXCL1/5, a secreted protein, was significantly higher in CR cells compared to the parental cells. In these CR cells, CXCL1/5 expression was coordinately regulated by SNAI2/NFKB and transactivated EGFR through CXCR/MMPI/EGF axis via autocrine singling. We also observed that combined cetuximab/MEK inhibitor not only showed growth inhibition but also reduced the secreted amounts of CXCL1/5. We further found that serum CXCL1/5 level was positively correlated with the presence of RAS/RAF mutation in colon cancer patients during cetuximab therapy, suggesting its role as a biomarker. These data indicated that the application of serum CXCL1/5 could be a potential serologic biomarker for predicting resistance to EGFR therapy in colorectal cancer.

CXCL1: Gene, Promoter, Regulation of Expression, mRNA Stability, Regulation of Activity in the Intercellular Space

CXCL1 is one of the most important chemokines, part of a group of chemotactic cytokines involved in the development of many inflammatory diseases. It activates CXCR2 and, at high levels, CXCR1. The expression of CXCL1 is elevated in inflammatory reactions and also has important functions in physiology, including the induction of angiogenesis and recruitment of neutrophils. Due to a lack of reviews that precisely describe the regulation of CXCL1 expression and function, in this paper, we present the mechanisms of CXCL1 expression regulation with a special focus on cancer. We concentrate on the regulation of CXCL1 expression through the regulation of CXCL1 transcription and mRNA stability, including the involvement of NF-κB, p53, the effect of miRNAs and cytokines such as IFN-γ, IL-1β, IL-17, TGF-β and TNF-α. We also describe the mechanisms regulating CXCL1 activity in the extracellular space, including proteolytic processing, CXCL1 dimerization and the influence of the ACKR1/DARC receptor on CXCL1 localization. Finally, we explain the role of CXCL1 in cancer and possible therapeutic approaches directed against this chemokine.

Involvement of Macrophages in Proliferation of Prostate Cancer Cells Infected with Trichomonas vaginalis

Macrophages play a key role in chronic inflammation, and are the most abundant immune cells in the tumor microenvironment. We investigated whether an interaction between inflamed prostate cancer cells stimulated with Trichomonas vaginalis and macrophages stimulates the proliferation of the cancer cells. Conditioned medium was prepared from T. vaginalis-infected (TCM) and uninfected (CM) mouse prostate cancer (PCa) cell line (TRAMP-C2 cells). Thereafter conditioned medium was prepared from macrophages (J774A.1 cell line) after incubation with CM (MCM) or TCM (MTCM). When TRAMP-C2 cells were stimulated with T. vaginalis, protein and mRNA levels of CXCL1 and CCL2 increased, and migration of macrophages toward TCM was more extensive than towards CM. Macrophages stimulated with TCM produced higher levels of CCL2, IL-6, TNF-α, their mRNAs than macrophages stimulated with CM. MTCM stimulated the proliferation and invasiveness of TRAMP-C2 cells as well as the expression of cytokine receptors (CCR2, GP130, CXCR2). Importantly, blocking of each cytokine receptors with anti-cytokine receptor antibody significantly reduced the proliferation and invasiveness of TRAMP-C2 cells. We conclude that inflammatory mediators released by TRAMP-C2 cells in response to infection by T. vaginalis stimulate the migration and activation of macrophages and the activated macrophages stimulate the proliferation and invasiveness of the TRAMP-C2 cells via cytokine-cytokine receptor binding. Our results therefore suggested that macrophages contribute to the exacerbation of PCa due to inflammation of prostate cancer cells reacted with T. vaginalis.

Activation of the adipocyte CREB/CRTC pathway in obesity

Obesity is a major risk factor for the development of type II diabetes. Increases in adipose tissue mass trigger insulin resistance via the release of pro-inflammatory cytokines from adipocytes and macrophages. CREB and the CRTC coactivators have been found to promote insulin resistance in obesity, although the mechanism is unclear. Here we show that high fat diet feeding activates the CREB/CRTC pathway in adipocytes by decreasing the expression of SIK2, a Ser/Thr kinase that phosphorylates and inhibits CRTCs. SIK2 levels are regulated by the adipogenic factor C/EBPα, whose expression is reduced in obesity. Exposure to PPARγ agonist rescues C/EBPα expression and restores SIK2 levels. CRTC2/3 promote insulin resistance via induction of the chemokines CXCL1/2. Knockout of CRTC2/3 in adipocytes reduces CXCL1/2 expression and improves insulin sensitivity. As administration of CXCL1/2 reverses salutary effects of CRTC2/3 depletion, our results demonstrate the importance of the CREB/CRTC pathway in modulating adipose tissue function.

Ketogenesis alleviates TNFα-induced apoptosis and inflammatory responses in intestinal cells

The disturbance of strictly regulated self-regeneration in mammalian intestinal epithelium is associated with various intestinal disorders, particularly inflammatory bowel diseases (IBDs). TNFα, which plays a critical role in the pathogenesis of IBDs, has been reported to inhibit production of ketone bodies such as β-hydroxybutyrate (βHB). However, the role of ketogenesis in the TNFα-mediated pathological process is not entirely known. Here, we showed the regulation and role of HMGCS2, the rate-limiting enzyme of ketogenesis, in TNFα-induced apoptotic and inflammatory responses in intestinal epithelial cells. Treatment with TNFα dose-dependently decreased protein and mRNA expression of HMGCS2 and its product, βHB production in human colon cancer cell lines HT29 and Caco2 cells and mouse small intestinal organoids. Moreover, the repressed level of HMGCS2 protein was found in intestinal epithelium of IBD patients with Crohn's disease and ulcerative colitis as compared with normal tissues. Furthermore, knockdown of HMGCS2 enhanced and in contrast, HMGCS2 overexpression attenuated, the TNFα-induced apoptosis and expression of pro-inflammatory chemokines (CXCL1-3) in HT29, Caco2 cells and DLD1 cells, respectively. Treatment with βHB or rosiglitazone, an agonist of PPARγ, which increases ketogenesis, attenuated TNFα-induced apoptosis in the intestinal epithelial cells. Finally, HMGCS2 knockdown enhanced TNFα-induced reactive oxygen species (ROS) generation. In addition, hydrogen peroxide, the major ROS contributing to intestine injury, decreased HMGCS2 expression and βHB production in the intestinal cells and mouse organoids. Our findings demonstrate that increased ketogenesis attenuates TNFα-induced apoptosis and inflammation in intestinal cells, suggesting a protective role for ketogenesis in TNFα-induced intestinal pathologies.

Conditions Mimicking the Cancer Microenvironment Modulate the Functional Outcome of Human Chorionic Villus Mesenchymal Stem/Stromal Cells in vitro

Mesenchymal stem/stromal cells isolated from chorionic villi of human term placentae (CV-MSCs) possess unique biological characters. They exhibit self-renewal, directional migration, differentiation, and immunomodulatory effects on other cell lineages, by virtue of which they can be utilized as therapeutic carriers, for drug targeting, and therapy. Tumors display characteristic features of a damaged tissue microenvironment, which is saturated with conditions such as hypoxia, sustained inflammation, and increased oxidative stress. CV-MSCs function normally in a high oxidative stress environment induced by hydrogen peroxide (H₂O₂) and glucose and also protect endothelial cells from their damaging effects. For their therapeutic applications in a disease like cancer, it is necessary to ascertain the effects of tumor microenvironment on their functional outcome. In this study, we investigated the functional activities, of CV-MSCs in response to conditioned media (CM) obtained from the culture of breast cancer cell line MDA-231 (CM-MDA231). CV-MSCs were exposed to CM-MDA231 for different spatio-temporal conditions, and their biological functions as well as modulation in gene expression were evaluated. Effect of CM-MDA231 on factors responsible for changes in functional outcome were also investigated at the protein levels. CV-MSCs exhibited significant reduction in proliferation but increased adhesion and migration after CM-MDA231 treatment. Interestingly, there was no change in their invasion potential. CM-MDA231 treatment modulated expression of various genes involved in important cellular events including, integration, survival, message delivery and favorable outcome after transplantation. Analysis of pathways related to cell cycle regulation revealed significant changes in the expression of p53, and increased phosphorylation of Retinoblastoma (Rb) and Checkpoint Kinase 2 in CV-MSCs treated with CM-MDA231. To summarize, these data reveal that CV-MSCs retain the ability to survive, adhere, and migrate after sustained treatment with CM-MDA231, a medium that mimics the cancer microenvironment. These properties of CV-MSCs to withstand the inflammatory tumor like microenvironment prove that they may make useful candidate in a stem cell based therapy against cancer. However, further pre-clinical studies are needed to validate their therapeutic usage.

The C-X-C Motif Chemokine Ligand 1 Sustains Breast Cancer Stem Cell Self-Renewal and Promotes Tumor Progression and Immune Escape Programs

Breast cancer (BC) mortality is mainly due to metastatic disease, which is primarily driven by cancer stem cells (CSC). The chemokine C-X-C motif ligand-1 (CXCL1) is involved in BC metastasis, but the question of whether it regulates breast cancer stem cell (BCSC) behavior is yet to be explored. Here, we demonstrate that BCSCs express CXCR2 and produce CXCL1, which stimulates their proliferation and self-renewal, and that CXCL1 blockade inhibits both BCSC proliferation and mammosphere formation efficiency. CXCL1 amplifies its own production and remarkably induces both tumor-promoting and immunosuppressive factors, including SPP1/OPN, ACKR3/CXCR7, TLR4, TNFSF10/TRAIL and CCL18 and, to a lesser extent, immunostimulatory cytokines, including IL15, while it downregulates CCL2, CCL28, and CXCR4. CXCL1 downregulates TWIST2 and SNAI2, while it boosts TWIST1 expression in association with the loss of E-Cadherin, ultimately promoting BCSC epithelial-mesenchymal transition. Bioinformatic analyses of transcriptional data obtained from BC samples of 1,084 patients, reveals that CXCL1 expressing BCs mostly belong to the Triple-Negative (TN) subtype, and that BC expression of CXCL1 strongly correlates with that of pro-angiogenic and cancer promoting genes, such as CXCL2-3-5-6, FGFBP1, BCL11A, PI3, B3GNT5, BBOX1, and PTX3, suggesting that the CXCL1 signaling cascade is part of a broader tumor-promoting signaling network. Our findings reveal that CXCL1 functions as an autocrine growth factor for BCSCs and elicits primarily tumor progression and immune escape programs. Targeting the CXCL1/CXCR2 axis could restrain the BCSC compartment and improve the treatment of aggressive BC.

Exploration of identifying novel serum biomarkers for malignant mesothelioma using iTRAQ combined with 2D-LC-MS/MS

Malignant mesothelioma (MM) is an aggressive cancer linked to asbestos exposure. Its poor prognosis makes early diagnosis extremely important, which would provide an opportunity for early treatment and potentially changing outcomes. This study aimed to explore the underlying mechanisms of MM and discover novel noninvasive biomarkers for the diagnosis of malignant mesothelioma. Using Isobaric tags for relative and absolute quantitation (iTRAQ) combined with two-dimensional liquid chromatography/tandem mass spectrometry (2D LC-MS/MS), a total of 145 differentially expressed serum proteins were identified between MM patients and healthy controls. The identified proteins were further analyzed by bioinformatics, out of which three candidate biomarkers (Filamin A (FLNA), Fibulin 1 (FBLN1) and Thrombospondin-1 (TSP-1)) were validated in large cohorts of patients with asbestos-related diseases including MM patients by ELISA assay. Receiver operating characteristic (ROC) curve analysis showed that serum FLNA, FBLN1 and TSP-1 had high diagnostic values in distinguishing MM patients from healthy controls, individuals with asbestos exposure (AE), and patients with pleural plaques (PP) or asbestosis. Meanwhile, serum FBLN1 and TSP-1 possessed good diagnostic values in distinguishing asbestosis patients from healthy controls and individuals with AE. The combination of FLNA, FBLN1, and TSP-1 proteins had higher sensitivity and specificity in discriminating patients with MM, PP and asbestosis. Our findings indicated that analysis of serum proteome using iTRAQ is a feasible strategy for biomarker discovery, and serum FLNA, FBLN1 and TSP-1 may be promising candidates for diagnosis of malignant mesothelioma and screening of at-risk individuals.

Research trends in pharmacological modulation of tumor-associated macrophages

As one of the most abundant immune cell populations in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play important roles in multiple solid malignancies, including breast cancer, prostate cancer, liver cancer, lung cancer, ovarian cancer, gastric cancer, pancreatic cancer, and colorectal cancer. TAMs could contribute to carcinogenesis, neoangiogenesis, immune-suppressive TME remodeling, cancer chemoresistance, recurrence, and metastasis. Therefore, reprogramming of the immune-suppressive TAMs by pharmacological approaches has attracted considerable research attention in recent years. In this review, the promising pharmaceutical targets, as well as the existing modulatory strategies of TAMs were summarized. The chemokine-chemokine receptor signaling, tyrosine kinase receptor signaling, metabolic signaling, and exosomal signaling have been highlighted in determining the biological functions of TAMs. Besides, both preclinical research and clinical trials have suggested the chemokine-chemokine receptor blockers, tyrosine kinase inhibitors, bisphosphonates, as well as the exosomal or nanoparticle-based targeting delivery systems as the promising pharmacological approaches for TAMs deletion or reprogramming. Lastly, the combined therapies of TAMs-targeting strategies with traditional treatments or immunotherapies as well as the exosome-like nanovesicles for cancer therapy are prospected.

Epithelial-stromal communication via CXCL1-CXCR2 interaction stimulates growth of ovarian cancer cells through p38 activation

PURPOSE

Paracrine interactions with the stromal environment, including fibroblasts, may be important in the pathogenesis of ovarian cancer. Here, we evaluated the effect of conditioned media derived from ovarian fibroblasts (fibroblast-CMs) and their major cytokines on the growth of ovarian cancer cells, as well as the involvement of mitogen-activated protein kinases (MAPKs) and AKT in mediating this effect.

METHODS

Ovarian cancer cells were cultured in serum-free media (SF), or conditioned media of fibroblasts derived from normal ovary (CM1) and ovarian tumor tissue (CM2). Cell proliferation was measured by MTT assay. Phosphorylation of MAPKs and AKT was evaluated by Western blotting. Specific inhibitors of MAPKs and AKT were used to evaluate their respective involvement in mediating increased cell growth. Cytokine levels in fibroblast-CMs were measured using Luminex assays. Immunohistochemical staining was conducted for CXCL1, CXCR2 and phosphorylated p38 in primary ovarian tumors.

RESULTS

CM1 and CM2 significantly increased the growth of ovarian cancer cells relative to SF. In OVCAR3 and OVCAR4 cells, p38 phosphorylation was strongly induced by fibroblast-CMs, and pre-treatment with a p38 inhibitor prevented the growth increase induced by fibroblast-CMs. Fibroblasts secreted high levels of IL-6, IL-8, MCP1 and CXCL1. Treatment with only CXCL1 (1 μg/ml) increased cell growth and p38 phosphorylation. Treatment with a CXCR2 inhibitor effectively prevented p38 activation and cell growth induced by fibroblast-CMs. High expression of both CXCL1 and CXCR2 correlated with high expression of phosphorylated p38 in primary ovarian tumors.

CONCLUSIONS

From our data, we conclude that CXCL1 is a key factor derived from ovarian fibroblasts that is responsible for increased ovarian cancer cell growth in part through p38 activation. Phosphorylated p38 can be used as a biomarker to predict CXCL1-CXCR2 interaction in vivo.

Fusobacterium nucleatum host-cell binding and invasion induces IL-8 and CXCL1 secretion that drives colorectal cancer cell migration

Fusobacterium nucleatum is implicated in accelerating colorectal cancer (CRC) and is found within metastatic CRC cells in patient biopsies. Here, we found that bacterial invasion of CRC cells and cocultured immune cells induced a differential cytokine secretion that may contribute to CRC metastasis. We used a modified galactose kinase markerless gene deletion approach and found that F. nucleatum invaded cultured HCT116 CRC cells through the bacterial surface adhesin Fap2. In turn, Fap2-dependent invasion induced the secretion of the proinflammatory cytokines IL-8 and CXCL1, which are associated with CRC progression and promoted HCT116 cell migration. Conditioned medium from F. nucleatum-infected HCT116 cells caused naïve cells to migrate, which was blocked by depleting CXCL1 and IL-8 from the conditioned medium. Cytokine secretion from HCT116 cells and cellular migration were attenuated by inhibiting F. nucleatum host-cell binding and entry using galactose sugars, l-arginine, neutralizing membrane protein antibodies, or fap2 deletion. F. nucleatum also induces the mobilization of immune cells in the tumor microenvironment. However, in neutrophils and macrophages, the bacterial-induced secretion of cytokines was Fap2 independent. Thus, our findings show that F. nucleatum both directly and indirectly modulates immune and cancer cell signaling and migration. Because increased IL-8 and CXCL1 production in tumors is associated with increased metastatic potential and cell seeding, poor prognosis, and enhanced recruitment of tumor-associated macrophages and fibroblasts, we propose that inhibition of host-cell binding and invasion, potentially through vaccination or novel galactoside compounds, could be an effective strategy for reducing F. nucleatum-associated CRC metastasis.

Cytokines and Chemokines as Mediators of Prostate Cancer Metastasis

The consequences of prostate cancer metastasis remain severe, with huge impact on the mortality and overall quality of life of affected patients. Despite the convoluted interplay and cross talk between various cell types and secreted factors in the metastatic process, cytokine and chemokines, along with their receptors and signaling axis, constitute important factors that help drive the sequence of events that lead to metastasis of prostate cancer. These proteins are involved in extracellular matrix remodeling, epithelial-mesenchymal-transition, angiogenesis, tumor invasion, premetastatic niche creation, extravasation, re-establishment of tumor cells in secondary organs as well as the remodeling of the metastatic tumor microenvironment. This review presents an overview of the main cytokines/chemokines, including IL-6, CXCL12, TGFβ, CXCL8, VEGF, RANKL, CCL2, CX3CL1, IL-1, IL-7, CXCL1, and CXCL16, that exert modulatory roles in prostate cancer metastasis. We also provide extensive description of their aberrant expression patterns in both advanced disease states and metastatic sites, as well as their functional involvement in the various stages of the prostate cancer metastatic process.

Associations of CXCL1 gene 5'UTR variations with ovarian cancer

BACKGROUND

There are about 2.4 hundred thousand new cases and 1.5 hundred thousand deaths of ovarian cancer (OC) annually in the world. Chronic inflammation is a risk factor for OC. C-X-C motif chemokine ligand 1 (CXCL1) defects may facilitate inflammation and transactivate EGFR in ovarian cancer, but the precise haplotypes associated with the potential diseases remained largely unknown. In this work, we characterized CXCL1 gene variations to elucidate their possible associations with OC.

METHODS

We analyzed the CXCL1 gene for 300 OC patients with 400 healthy participants as controls. The statistical analyses and Hardy-Weinberg equilibrium tests of the patients and control populations were conducted using the SPSS software (version 19.0) and Plink (version 1.9).

RESULTS

The variants rs11547681, rs201090116, rs199791199, rs181868085, rs4074 and rs1814092 within or near the CXCL1 gene were characterized. The genetic heterozygosity of rs11547681 and rs4074 was very high. Statistical analysis showed that the variant rs11547681 in the gene was closely associated with the risk of OC in the Chinese Han population, although this variant was not associated with FIGO stages or pathological grades of the patients.

CONCLUSIONS

Rs11547681 in CXCL1 gene was associated with the risk of OC in the Chinese Han population.

Oxidative stress enhanced the transforming growth factor-β2-induced epithelial-mesenchymal transition through chemokine ligand 1 on ARPE-19 cell

Fibroblast-like transformation of retinal pigment epithelial (RPE) cells is a pathological feature of proliferative vitreoretinopathy (PVR) that may cause blindness. The effect of oxidative stress alone or together with transforming growth factor-beta 2 (TGF-β2) on epithelial-mesenchymal transformation (EMT) is not fully understood in RPE. TGF-β2 induced the upregulation EMT markers including α-smooth muscle actin (α-SMA), Snail, and Slug and downregulation of E-cadherin (E-cad) in ARPE-19 cells. Hydrogen peroxide (H₂O₂) not only upregulated α-SMA but also enhanced the effect of TGF-β2 on the expression of Snail and Slug. The CXCL family of cytokines could be the mediators of EMT induced by H₂O₂ and TGF-β2. H₂O₂ induced CXCL1, that upregulated α-SMA and fibronectin. Both SB225002, an inhibitor of CXCR2, and antioxidant N-acetylcysteine suppressed the TGF-β2-induced EMT in ARPE-19 cells. Taken together, the results suggest that oxidative stress enhanced TGF-β2-induced EMT through the possible autocrine effect of CXCL1 on CXCR2 in ARPE-19 cells.

CXCL1 is upregulated during the development of ileus resulting in decreased intestinal contractile activity

BACKGROUND

Although the development of ileus is widespread and negatively impacts patient outcomes, the mechanism by which ileus develops remains unclear. The purpose of our study was to examine the contribution of myogenic mechanisms to postoperative ileus development and the involvement of inflammation in mediating intestinal smooth muscle dysfunction.

METHODS

Contractile activity and the effects of CXCL1 were studied in a gut manipulation model.

KEY RESULTS

Contraction amplitude in the ileum decreased significantly, while tone increased significantly in response to gut manipulation. Differences in contraction amplitude were affected by tetrodotoxin at earlier time points, but not at later time points. Agonist-induced contractions in the small intestine decreased significantly with ileus development. Intestinal transit slowed significantly after the induction of ileus. Myosin light chain phosphorylation was significantly decreased and edema increased significantly in the intestinal wall. Conditioned media from mechanically activated macrophages depressed intestinal contractile activity. CXCL1 (GroA) was significantly increased in the mechanically activated macrophages and intestinal smooth muscle within 1 hour after induction of ileus compared with control cells and sham animals, respectively. Treatment with CXCL1 significantly decreased contraction amplitude and agonist-induced contractile activity and increased tone in the small intestine. In the gut manipulation model, treatment with a CXCR2 antagonist prevented the decrease in agonist-induced contractile activity but not contraction amplitude.

CONCLUSIONS & INFERENCES

These data suggest that CXCL1, released from macrophages during intestinal wall stress, can suppress intestinal contractile activity. CXCL1 is a potential target for preventing or treating ileus in trauma patients.

CXCL1-LCN2 paracrine axis promotes progression of prostate cancer via the Src activation and epithelial-mesenchymal transition

BACKGROUND

Mechanisms driving the progression of castration-resistant prostate cancer are believed to relate substantially to the tumor microenvironment. However, the cross-talks between tumor epithelial cell, stromal cells, and immune cells are yet to be fully elucidated. The present study aims to determine the role of chemokine and neutrophil derived cytokine paracrine axis in mediating the interaction between tumor cells, stromal myofibroblasts, and neutrophils in the tumor microenvironment of prostate cancer.

METHODS

To identify myofibroblasts and neutrophil derived specific proteins affecting progression of prostate cancer, bioinformatics analyses were firstly performed in independent human prostate cancer gene expression data sets from the GEO data bank. Expression of stromal myofibroblasts secretory chemokine CXCL1 and neutrophil derived cytokine LCN2 was evaluated in prostate tissues via immunohistochemistry assay. We further investigated the effect of CXCL1 and LCN2 on prostate cancer using in vivo and in vitro models, and explored the underlying signal transduction pathways.

RESULTS

A CXCL1-LCN2 paracrine network was confirmed in prostate cancer tissue samples, which was correlated with the biochemical recurrence of prostate cancer. Of note, CXCL1-LCN2 axis activates Src signaling, triggers the epithelial-mesenchymal transition (EMT), consequently promotes the migration of prostate cancer cells, leading to enhanced tumor metastasis.

CONCLUSIONS

Our findings may provide enhanced insight into the interactions of carcinoma-stromal cells and immune cells linked to prostate cancer progression, wherein CXCL1-LCN2 axis is a key contributor to prostate cancer cells migration. These data indicate tumor microenvironment and Src signaling pathway may be potential therapeutic targets of prostate cancer treatment.

A pooled single-cell genetic screen identifies regulatory checkpoints in the continuum of the epithelial-to-mesenchymal transition

Integrating single-cell trajectory analysis with pooled genetic screening could reveal the genetic architecture that guides cellular decisions in development and disease. We applied this paradigm to probe the genetic circuitry that controls epithelial-to-mesenchymal transition (EMT). We used single-cell RNA sequencing to profile epithelial cells undergoing a spontaneous spatially determined EMT in the presence or absence of transforming growth factor-β. Pseudospatial trajectory analysis identified continuous waves of gene regulation as opposed to discrete 'partial' stages of EMT. KRAS was connected to the exit from the epithelial state and the acquisition of a fully mesenchymal phenotype. A pooled single-cell CRISPR-Cas9 screen identified EMT-associated receptors and transcription factors, including regulators of KRAS, whose loss impeded progress along the EMT. Inhibiting the KRAS effector MEK and its upstream activators EGFR and MET demonstrates that interruption of key signaling events reveals regulatory 'checkpoints' in the EMT continuum that mimic discrete stages, and reconciles opposing views of the program that controls EMT.

CXCL1 stimulates migration and invasion in ER‑negative breast cancer cells via activation of the ERK/MMP2/9 signaling axis

Chemokine (C‑X‑C motif) ligand 1 (CXCL1), a member of the CXC chemokine family, has been reported to be a critical factor in inflammatory diseases and tumor progression; however, its functions and molecular mechanisms in estrogen receptor α (ER)‑negative breast cancer (BC) remain largely unknown. The present study demonstrated that CXCL1 was upregulated in ER‑negative BC tissues and cell lines compared with ER‑positive tissues and cell lines. Treatment with recombinant human CXCL1 protein promoted ER‑negative BC cell migration and invasion in a dose‑dependent manner, and stimulated the activation of phosphorylated (p)‑ extracellular signal‑regulated kinase (ERK)1/2, but not p‑STAT3 or p‑AKT. Conversely, knockdown of CXCL1 in BC cells attenuated these effects. Additionally, CXCL1 increased the expression of matrix metalloproteinase (MMP)2/9 via the ERK1/2 pathway. Inhibition of MEK1/2 by its antagonist U0126 reversed the effects of CXCL1 on MMP2/9 expression. Furthermore, immunohistochemical analysis revealed a strong positive association between CXCL1 and p‑ERK1/2 expression levels in BC tissues. In conclusion, the present study demonstrated that CXCL1 is highly expressed in ER‑negative BC, and stimulates BC cell migration and invasion via the ERK/MMP2/9 pathway. Therefore, CXCL1 may serve as a potential therapeutic target in ER‑negative BC.

JAK/STAT inhibition in macrophages promotes therapeutic resistance by inducing expression of protumorigenic factors

Tumor-associated macrophages contribute to tumor progression and therapeutic resistance in breast cancer. Within the tumor microenvironment, tumor-derived factors activate pathways that modulate macrophage function. Using in vitro and in vivo models, we find that tumor-derived factors induce activation of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathway in macrophages. We also demonstrate that loss of STAT3 in myeloid cells leads to enhanced mammary tumorigenesis. Further studies show that macrophages contribute to resistance of mammary tumors to the JAK/STAT inhibitor ruxolitinib in vivo and that ruxolitinib-treated macrophages produce soluble factors that promote resistance of tumor cells to JAK inhibition in vitro. Finally, we demonstrate that STAT3 deletion and JAK/STAT inhibition in macrophages increases expression of the protumorigenic factor cyclooxygenase-2 (COX-2), and that COX-2 inhibition enhances responsiveness of tumors to ruxolitinib. These findings define a mechanism through which macrophages promote therapeutic resistance and highlight the importance of understanding the impact of targeted therapies on the tumor microenvironment.

Inflammatory Breast Cancer Promotes Development of M2 Tumor-Associated Macrophages and Cancer Mesenchymal Cells through a Complex Chemokine Network

Inflammatory breast cancer (IBC) is a highly aggressive form of breast cancer that displays profound cancer stem cell (CSC) and mesenchymal features that promote rapid metastasis. Another hallmark of IBC is high infiltration of M2 tumor-associated (immune-suppressing) macrophages. The molecular mechanism that drives these IBC phenotypes is not well understood. Using patient breast tumor specimens, breast cancer cell lines, and a patient-derived xenograft model of IBC, we demonstrate that IBC strongly expresses IL8 and growth-regulated oncogene (GRO) chemokines that activate STAT3, which promotes development of high levels of CSC-like cells and a mesenchymal phenotype. We also show that IBC expresses high levels of many monocyte recruitment and macrophage polarization factors that attract and differentiate monocytes into tumor-promoting, immune-suppressing M2-like macrophages. The M2 macrophages in turn were found to secrete high levels of IL8 and GRO chemokines, thereby creating a feed-forward chemokine loop that further drives an IBC epithelial-to-mesenchymal transition. Our study uncovers an intricate IBC-initiated autocrine-paracrine signaling network between IBC cells and monocytes that facilitates development of this highly aggressive form of breast cancer. SIGNIFICANCE: This study uncovers a signaling network in which IBC cells commandeer macrophages to become tumor-promoting, and they in turn drive IBC cells to be more cancer stem-like, mesenchymal, and aggressive.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/13/3360/F1.large.jpg.

Reduced FRG1 expression promotes prostate cancer progression and affects prostate cancer cell migration and invasion

BACKGROUND

Prostate cancer is the most common form of cancer in males and accounts for high cancer related deaths. Therapeutic advancement in prostate cancer has not been able to reduce the mortality burden of prostate cancer, which warrants further research. FRG1 which affects angiogenesis and cell migration in Xenopus, can be a potential player in tumorigenesis. In this study, we investigated the role of FRG1 in prostate cancer progression.

METHODS

Immunohistochemistry was performed to determine FRG1 expression in patient samples. FRG1 expression perturbation was done to investigate the effect of FRG1 on cell proliferation, migration and invasion, in DU145, PC3 and LNCaP cells. To understand the mechanism, we checked expression of various cytokines and MMPs by q-RT PCR, signaling molecules by western blot, in FRG1 perturbation sets. Results were validated by use of pharmacological inhibitor and activator and, western blot.

RESULTS

In prostate cancer tissue, FRG1 levels were significantly reduced, compared to the uninvolved counterpart. FRG1 expression showed variable effect on PC3 and DU145 cell proliferation. FRG1 levels consistently affected cell migration and invasion, in both DU145 and PC3 cells. Ectopic expression of FRG1 led to significant reduction in cell migration and invasion in both DU145 and PC3 cells, reverse trends were observed with FRG1 knockdown. In androgen receptor positive cell line LNCaP, FRG1 doesn't affect any of the cell properties. FRG1 knockdown led to significantly enhanced expression of GM-CSF, MMP1, PDGFA and CXCL1, in PC3 cells and, in DU145, it led to higher expression of GM-CSF, MMP1 and PLGF. Interestingly, FRG1 knockdown in both the cell lines led to activation of p38 MAPK. Pharmacological activation of p38 MAPK led to increase in the expression of GM-CSF and PLGF in DU145 whereas in PC3 it led to enhanced expression of GM-CSF, MMP1 and CXCL1. On the other hand, inhibition of p38 MAPK led to reduction in the expression of above mentioned cytokines.

CONCLUSION

FRG1 expression is reduced in prostate adenocarcinoma tissue. FRG1 expression affects migration and invasion in AR negative prostate cancer cells through known MMPs and cytokines, which may be mediated primarily via p38 MAPK activation.

Epigenetic mechanisms and implications in tendon inflammation (Review)

Cellular inflammation is not just an immediate response following pathogenic infections or resulting from damage due to injury, it is also associated with normal physiological functions, including wound healing and tissue repair. The existence of such a definitive role in normal physiology and in disease pathology indicates the presence of a regulatory mechanism that is tightly controlled in normal cells. A tight control over gene expression is associated with regulatory mechanisms in the cells, which can be either inducible or epigenetic. Among other intracellular mechanisms that contribute to epigenetic gene regulation, DNA methylation has been shown to maintain a tight control over gene expression through the actions of DNA methyltransferases (DNMTs). With a clear role in developmental and tissue‑specific temporal gene regulation, the involvement of DNMTs is evident in normal and pathological conditions. In this review article, inflammation in tendons associated with disease pathology and tissue repair or regeneration at the musculoskeletal joints is critically reviewed. More specifically, the review focuses on known epigenetic mechanisms and their role in the clinical presentation of the disease in human joint disorders associated with tendon inflammation, with an emphasis on the gene regulatory mechanisms that are controlled through DNA methylation, histone deacetylation, and microRNAs.

CXCL1 Derived from Mammary Fibroblasts Promotes Progression of Mammary Lesions to Invasive Carcinoma through CXCR2 Dependent Mechanisms

With improved screening methods, the numbers of abnormal breast lesions diagnosed in women have been increasing over time. However, it remains unclear whether these breast lesions will develop into invasive cancers. To more effectively predict the outcome of breast lesions and determine a more appropriate course of treatment, it is important to understand the underlying mechanisms that regulate progression of non-invasive lesions to invasive breast cancers. A hallmark of invasive breast cancers is the accumulation of fibroblasts. Fibroblast proliferation and activation in the mammary gland is in part regulated by the Transforming Growth Factor beta1 pathway (TGF-β). In animal models, TGF-β suppression of CCL2 and CXCL1 chemokine expression is associated with metastatic progression of mammary carcinomas. Here, we show that transgenic overexpression of the Polyoma middle T viral antigen in the mouse mammary gland of C57BL/6 mice results in slow growing non-invasive lesions that progress to invasive carcinomas in a stage dependent manner. Invasive carcinomas are associated with accumulation of fibroblasts that show decreased TGF-β expression and high levels of CXCL1, but not CCL2. Using co-transplant models, we show that decreased TGF-β signaling in fibroblasts contribute to mammary carcinoma progression through enhancement of CXCL1/CXCR2 dependent mechanisms. Using cell culture models, we show that CXCL1 mediated mammary carcinoma cell invasion through NF-κB, AKT, Stat3 and p42/44MAPK dependent mechanisms. These studies provide novel mechanistic insight into the progression of pre-invasive lesions and identify new stromal biomarkers, with important prognostic implications.

Curcumin gum formulation for prevention of oral cavity head and neck squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

Head and neck squamous cell carcinoma represents the sixth most common cancer. As a result of field cancerization, second primaries and recurrences are high. Hence, research has focused on chemoprevention. Curcumin, a polyphenol compound with anticarcinogenic properties, is one such promising nutraceutical. As poor bioavailability limits curcumin's use, a novel gum formulation was tested allowing for direct mucosal absorption into the bloodstream. This preliminary study validates curcumin gum efficacy by assessing release and transmucosal absorption, along with measuring its effects on serum cytokine levels.

STUDY DESIGN

Clinical trial.

METHODS

Protocols consisting of initial chew (chewing gum for 30 minutes) and revised chew (alternating chewing and parking gum against buccal mucosa for 30 minutes) were tested in healthy volunteers. High-performance liquid chromatography measured remnant curcumin in chewed gum, serum, and saliva. Serum levels were assayed for 15 proinflammatory cytokines via multiplex analysis.

RESULTS

Revised chew samples demonstrated significantly higher curcumin release and absorption (P = .0078). Curcumin serum levels were significantly higher at 4 hours in samples > 2.0 g of curcumin release (P = .01). As saliva levels decreased, a concurrent increase in serum levels was observed, with no significance in the inverse relationship (P = .1423). When evaluating differences between gender, race, and age, the Asian population showed significantly lower curcumin release and serum levels (P = .009). CXCL1 (GRO-α) and TNF-α were significantly decreased in serum after chewing the gum (P = .036, P < .001, respectively).

CONCLUSIONS

Enhanced mucosal contact appears critical in improving curcumin release and absorption. CXCL1 and TNF-α both represent potential biomarkers for the future study of curcumin chemoprevention.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:1597-1603, 2019.

Functions of the CXC ligand family in the pancreatic tumor microenvironment

Therapeutic resistance is the major contributor to the poor prognosis of and low survival from pancreatic cancer (PC). Cancer progression is a complex process reliant on interactions between the tumor and the tumor microenvironment (TME). Members of the CXCL family of chemokines are present in the pancreatic TME and seem to play a vital role in regulating PC progression. As pancreatic tumors interact with the TME and with PC stem cells (CSCs), determining the roles of specific members of the CXCL family is vital to the development of improved therapies. This review highlights the roles of selected CXCLs in the interactions between pancreatic tumor and its stroma, and in CSC phenotypes, which can be used to identify potential treatment targets.

CXCL1 derived from tumor-associated macrophages promotes breast cancer metastasis via activating NF-κB/SOX4 signaling

Tumor-associated macrophages (TAMs) have been implicated in the promotion of breast cancer growth and metastasis, and multiple TAM-secreted cytokines have been identified associating with poor clinical outcomes. However, the therapeutic targets existing in the loop between TAMs and cancer cells are still required for further investigation. Here in, cytokine array validated that C-X-C motif chemokine ligand 1 (CXCL1) is the most abundant chemokine secreted by TAMs, and CXCL1 can promote breast cancer migration and invasion ability, as well as epithelial–mesenchymal transition in both mouse and human breast cancer cells. QPCR screening further validated SOX4 as the highest responsive gene following CXCL1 administration. Mechanistic study revealed that CXCL1 binds to SOX4 promoter and activates its transcription via NF-κB pathway. In vivo breast cancer xenografts demonstrated that CXCL1 silencing in TAMs results in a significant reduction in breast cancer growth and metastatic burden. Bioinformatic analysis and clinical investigation finally suggested that high CXCL1 expression is significantly correlated with breast cancer lymph node metastasis, poor overall survival and basal-like subtype. Taken together, our results indicated that TAMs/CXCL1 promotes breast cancer metastasis via NF-κB/SOX4 activation, and CXCL1-based therapy might become a novel strategy for breast cancer metastasis prevention.

Growth-regulated oncogene-α from oral submucous fibrosis fibroblasts promotes malignant transformation of oral precancerous cells

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a common human malignancy and is usually preceded by the oral precancerous lesions. Oral submucous fibrosis (OSF) is one of the oral precancerous lesions with high incidence of malignant transformation. In addition to cancer cells, cancer-associated fibroblasts in the tumor microenvironment are correlated with cancer progression, but the role of fibroblasts from OSF in tumorigenesis and progression is still unknown. Growth-regulated oncogene-α (GRO-α), a member of CXC chemokine family, is related to tumorigenesis in several cancers. In this study, we would like to explore the role of GRO-α from OSF-associated fibroblasts in oral cancer progression.

METHODS

We isolated primary culture fibroblasts of normal, precancerous, and tumor tissues from patients with OSCC accompanied with OSF. A cytokine array was used to screen cytokine secretions in the conditioned media of the fibroblasts. A wound healing migration assay, WST-1 cell proliferation assay, rhodamine-phalloidin staining, and soft agar colony formation assay were used to investigate the effects of GRO-α on a dysplastic oral keratinocyte cell line (DOK) cell migration, growth, and anchorage-independent growth.

RESULTS

GRO-α was identified to be increased in conditioned media of OSF-associated fibroblasts. GRO-α promotes DOK cells proliferation, migration, and anchorage-independent growth through enhancing the EGFR/ERK signaling pathway, F-actin rearrangement, and stemness properties, respectively. Moreover, GRO-α neutralizing antibodies downregulated the conditioned medium-induced cell proliferation and migration of DOK.

CONCLUSION

GRO-α from OSF-associated fibroblasts paracrinally promotes oral malignant transformation and significantly contributes to OSCC development.

Chemokine (C-X-C motif) ligand 1 is associated with tumor progression and poor prognosis in patients with colorectal cancer

Chemokine (C-X-C motif) ligand 1 (CXCL1) is a chemotactic cytokine known to regulate cancer progression and invasion. However, the prognostic significance of CXCL1 expression in colorectal cancer (CRC) has not been fully characterized. The present study explored the clinicopathological significance and potential role of CXCL1 in the carcinogenesis and progression of CRC. The protein expression of CXCL1 was measured immunohistochemically in tissue microarrays constructed from 276 CRC patients. CXCL1 expression levels and their associations with clinicopathological characteristics and patient survival were evaluated. The effect of CXCL1 on glycolysis was also examined. High CXCL1 expression was detected in 165 (59.8%) cases. CXCL1 expression was correlated with tumor diameter (P=0.002), T stage (P=0.044), N stage (P=0.005), M stage (P=0.001), lymphovascular invasion (P=0.010), and carcinoembryonic antigen status (P=0.019). High CXCL1 expression was validated as an independent prognostic factor for overall survival (OS) and disease-free survival (DFS) by both univariate and multivariate Cox regression analyses (both P<0.05). Experimentally, expression of CXCL1 was knocked down by stable transfected short hairpin RNA, resulting in a significantly decreased rate of glycolysis both in in vitro assays and in patients' samples (P<0.05). Silencing the expression of CXCL1 decreased the levels of the glycolytic enzymes GLUT1, HK2, and LDHA. In conclusion, by inducing glycolysis, CXCL1 plays a crucial role in both cancer progression and metastasis in CRC patients. The CXCL1 expression level is an independent prognostic factor for both OS and DFS. Moreover, CXCL1 may serve as a new biomarker and potential therapeutic target for CRC treatment.

Knockdown of HDAC1 expression suppresses invasion and induces apoptosis in glioma cells

Glioma is the most common malignant tumor of the central nervous system, with a low survival rate of five years worldwide. Although high expression and prognostic value of histone deacetylase 1 (HDAC1) have been recently reported in various types of human tumors, the molecular mechanism underlying the biological function of HDAC1 in glioma is still unclear. We found that HDAC1 was elevated in glioma tissues and cell lines. HDAC1 expression was closely related with pathological grade and overall survival of patients with gliomas. Downregulation of HDAC1 inhibited cell proliferation, prevented invasion of glioma cell lines, and induced cell apoptosis. The expression of apoptosis and metastasis related molecules were detected by RT-PCR and Western blot, respectively, in U251 and T98G cells with HDAC1 knockdown. We found that HDAC1 knockdown upregulated expression of BIM, BAX, cleaved CASPASE3 and E-CADHERIN, and decreased expression of TWIST1, SNAIL and MMP9 in U251 and T98G cells with HDAC1 knockdown. In vivo data showed that knockdown of HDAC1 inhibited tumor growth in nude mice. In summary, HDAC1 may therefore be considered an unfavorable progression indicator for glioma patients, and may also serve as a potential therapeutic target.

Uev1A-Ubc13 promotes colorectal cancer metastasis through regulating CXCL1 expression via NF-кB activation

Colorectal cancer is the second most common cause of cancer-related death worldwide. Uncontrolled growth and distant metastasis are hallmarks of colorectal cancer. However, the precise etiological factors and the mechanisms are diverse and still largely unclear. The potential proto-oncogene UEV1A encodes a ubiquitin conjugating enzyme variant, which is required for Ubc13-catalyzed K63-linked poly-ubiquitination of target proteins and the activation of NF-кB, a transcription factor known to be involved in innate immunity, anti-apoptosis, inflammation and cancer. In order to understand the roles of Uev1A in colon cancer progression, we experimentally manipulated the Uev1A level in HCT116 colon cancer cells and found that UEV1A overexpression alone is sufficient to promote invasion in vitro and metastasis in vivo. This process is mediated by NF-κB activation and depends on its physical interaction with Ubc13. No expression of Uev1A was detected in histologically normal human colonic mucosa, but its expression was detected in human colorectal adenocarcinoma, which was closely correlated with nuclear p65 levels, an indicator of NF-κB activation. Uev1A protein was detected in 46% of primary tumors and 79% of metastatic tumors examined. Our experimental data establish that among NF-κB target genes, Uev1A-regulated CXCL1 expression plays a critical role in colon cell invasion and metastasis, a notion supported by the colon adenocarcinoma survey. Furthermore, experimental depletion of Uev1 in HCT116 cells reduces CXCL1 expression, and prevents cell invasion and tumor growth in a xenograft mouse model. These results identify Uev1A as a potential therapeutic target in the treatment of metastatic colorectal cancers.

Elevated CXCL1 increases hepatocellular carcinoma aggressiveness and is inhibited by miRNA-200a

In this study, we investigated the value of measurement of the chemokine CXCL1 in clinical management of hepatocellular carcinoma (HCC) and its possible role in the molecular pathogenesis of HCC. High CXCL1 expression predicted recurrence in HCC patients and promoted tumor progression in both in vivo and in vitro experimental systems. Overexpression of CXCL1 increased mitochondrial metabolism and activated the epithelial-to-mesenchymal transition (EMT). Using computational analysis we identified the microRNA miR-200a as a putative post-transcriptional regulator of CXCL1. We found that levels of miR-200a were inversely correlated with CXCL1 expression in HCC patient tissue samples by northern blot and qRT-PCR. Furthermore, CXCL1 was identified as a direct target which was bound and inhibited by miR- 200a. These findings provide new insights into the role of CXCL1 in HCC and its post-transcriptional regulation and suggest it may be a prognostic indicator for poor outcomes and a potential target for therapy.