Nuclear pattern of CXCR4 expression is associated with a better overall survival in patients with gastric cancer

Genetic and molecular biology of gastric cancer among Iranian patients: an update

Background

There is a declining trend of gastric cancer (GC) incidence in the world during recent years that is related to the development of novel diagnostic methods. However, there is still a high ratio of GC mortality among the Iranian population that can be associated with late diagnosis. Despite various reports about the novel diagnostic markers, there is not any general and standard diagnostic panel marker for Iranian GC patients. Therefore, it is required to determine an efficient and general panel of molecular markers for early detection.

Main body of the abstract

In the present review, we summarized all of the reported markers until now among Iranian GC patients to pave the way for the determination of a population-based diagnostic panel of markers. In this regard, we categorized these markers in different groups based on their involved processes to know which molecular process is more frequent during the GC progression among Iranians.

Conclusion

We observed that the non-coding RNAs are the main factors involved in GC tumorigenesis in this population.

Cancer Progression Mediated by CAFs Relating to HCC and Identification of Genetic Characteristics Influencing Prognosis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies, and although there are several treatment options, the overall results are not satisfactory. Cancer-associated fibroblasts (CAFs) can promote cancer progression through various mechanisms.

METHODS

HCC-associated mRNA data were sourced from The Cancer Genome Atlas database (TCGA) and International Cancer Genome Consortium (ICGC) database. First, the differentially expressed CAF-related genes (CAF-DEGs) were acquired by difference analysis and weighted gene coexpression network analysis (WGCNA). Moreover, a CAF-related risk model was built by Cox analysis. Kaplan-Meier (K-M) curves and receiver operating characteristic (ROC) curves were utilized to evaluate the validity of this risk model. Furthermore, enrichment analysis of differentially expressed genes (DEGs) between the high- and low-risk groups was executed to explore the functions relevant to the risk model. Furthermore, this study compared the differences in immune infiltration, immunotherapy, and drug sensitivity between the high- and low-risk groups. Finally, we verified the mRNA expression levels of selected prognostic genes by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

107 CAF-DEGs were identified in the HCC samples, and five prognosis-related genes (ACTA2, IGJ, CTHRC1, CXCL12, and LAMB1) were obtained by Cox analysis and utilized to build a CAF-related risk model. K-M analysis illustrated a low survival in the high-risk group, and ROC curves revealed that the risk model could accurately predict the 1-, 3-, and 5-year overall survival (OS) of HCC patients. In addition, Cox analysis demonstrated that the risk score was an independent prognostic factor. Enrichment analysis illustrated that DEGs between the high- and low-risk groups were related to immune response, amino acid metabolism, and fatty acid metabolism. Furthermore, risk scores were correlated with the tumor microenvironment, CAF scores, and TIDE scores, and CAF-related marker genes were positively correlated with all five model genes. Notably, the risk model was relevant to the sensitivity of chemotherapy drugs. Finally, the results of qRT-PCR demonstrated that the expression levels of 5 model genes were in accordance with the analysis.

CONCLUSION

A CAF-related risk model based on ACTA2, IGJ, CTHRC1, CXCL12, and LAMB1 was built and could be utilized to predict the prognosis and treatment of HCC.

Insights into Nuclear G-Protein-Coupled Receptors as Therapeutic Targets in Non-Communicable Diseases

G-protein-coupled receptors (GPCRs) comprise a large protein superfamily divided into six classes, rhodopsin-like (A), secretin receptor family (B), metabotropic glutamate (C), fungal mating pheromone receptors (D), cyclic AMP receptors (E) and frizzled (F). Until recently, GPCRs signaling was thought to emanate exclusively from the plasma membrane as a response to extracellular stimuli but several studies have challenged this view demonstrating that GPCRs can be present in intracellular localizations, including in the nuclei. A renewed interest in GPCR receptors' superfamily emerged and intensive research occurred over recent decades, particularly regarding class A GPCRs, but some class B and C have also been explored. Nuclear GPCRs proved to be functional and capable of triggering identical and/or distinct signaling pathways associated with their counterparts on the cell surface bringing new insights into the relevance of nuclear GPCRs and highlighting the nucleus as an autonomous signaling organelle (triggered by GPCRs). Nuclear GPCRs are involved in physiological (namely cell proliferation, transcription, angiogenesis and survival) and disease processes (cancer, cardiovascular diseases, etc.). In this review we summarize emerging evidence on nuclear GPCRs expression/function (with some nuclear GPCRs evidencing atypical/disruptive signaling pathways) in non-communicable disease, thus, bringing nuclear GPCRs as targets to the forefront of debate.

Prediction of relapse in stage I testicular germ cell tumor patients on surveillance: investigation of biomarkers

Background

Better biomarkers for assessing risk of relapse in stage I testicular germ cell tumor patients are needed, to complement classical histopathological variables. We aimed to assess the prognostic value of previously suggested biomarkers, related to proliferation (MIB-1 and TEX19) and to immune microenvironment (CXCL12, CXCR4, beta-catenin and MECA-79) in a surveillance cohort of stage I testicular germ cell tumor patients.

Methods

A total of 70 patients were included. Survival analyses were performed, including Cox regression models.

Results

Patients with vascular invasion and elevated human chorionic gonadotropin levels showed significantly poorer relapse-free survival in multivariable analysis (hazard ratio = 2.820, 95% confidence interval 1.257–6.328; hazard ratio = 3.025, 95% confidence interval 1.345–6.808). Patients with no vascular invasion but with MIB-1 staining in > 50% tumor cells showed significantly shorter relapse-free survival (p = 0.042). TEX19 nuclear immunoexpression was confirmed in spermatogonial cells, and weak cytoplasmic immunoexpression was depicted in 15/70 tumors, not significantly impacting survival. CXCL12 immunoexpression in tumor cells did not associate with relapse, but non-seminoma patients exhibiting vascular invasion and CXCL12-positive stromal/inflammatory cells showed significantly improved relapse-free survival (p = 0.015). Exclusively nuclear immunoexpression of CXCR4 associated with better relapse-free survival (p = 0.032), but not after adjusting for vascular invasion. Patients with higher beta-catenin scores showed a tendency for poorer relapse-free survival (p = 0.056). MECA-79 immunoexpression was absent.

Conclusions

The informative protein biomarkers (i.e., MIB-1, CXCL12, beta-catenin, and possibly CXCR4) may prove useful for risk-stratifying patients if validated in larger, multicentric and well-defined studies. Currently, classical histopathological features of testicular germ cell tumors remain key for relapse prediction.

Computer-aided assessment of the chemokine receptors CXCR3, CXCR4 and CXCR7 expression in gallbladder carcinoma

Gallbladder carcinoma (GBC) is a vicious and invasive disease. The major challenge in the clinical treatment of GBC is the lack of a suitable prognosis method. Chemokine receptors such as CXCR3, CXCR4 and CXCR7 play vital roles in the process of tumour progression and metastasis. Their expression levels and distribution are proven to be indicative of the progression of GBC, but are hard to be decoded by conventional pathological methods, and therefore, not commonly used in the prognosis of GBC. In this study, we developed a computer‐aided image analysis method, which we used to quantitatively measure the expression levels of CXCR3, CXCR4 and CXCR7 in the nuclei and cytoplasm of glandular and interstitial cells from a cohort of 55 GBC patients. We found that CXCR3, CXCR4 and CXCR7 expressions are associated with the clinicopathological variables of GBC. Cytoplasmic CXCR3, nuclear CXCR7 and cytoplasmic CXCR7 were significant predictive factors of histology invasion, whereas cytoplasmic CXCR4 and nuclear CXCR4 were significantly correlated with T and N stage and were associated with the overall survival and disease‐free survival. These results suggest that the quantification and localisation of CXCR3, CXCR4 and CXCR7 expressions in different cell types should be considered using computer‐aided assessment to improve the accuracy of prognosis in GBC.

Chemokine Receptor Expression Pattern Correlates to Progression of Conjunctival Melanocytic Lesions

Purpose

Chemokines play a role in the progression and metastatic spread of both cutaneous and uveal melanomas. The aim of this study was to examine the prognostic value of expression of chemokine receptors CCR7, CXCR4, and CCR10 in conjunctival melanocytic lesions.

Methods

In total, 44 conjunctival nevi, 21 cases of primary acquired melanosis (PAM) with atypia and 35 conjunctival melanomas, were included. After immunohistochemical staining for CCR7, CXCR4, and CCR10 the immunoreactive score (IRS) was determined. The findings were correlated for association with melanoma and development of metastasis. For mechanistic evaluation, we used a mouse melanoma metastasis model using two human conjunctival melanoma cell lines, CM2005.1 and CRMM1.

Results

All tested chemokines showed a significantly higher expression in conjunctival melanoma than conjunctival nevi. There was a statistically significant difference between the IRS in nevi and PAM with atypia for nuclear IRS in CCR10 (P = 0.03) and both nuclear and cytoplasmic IRS in CXCR4 (P < 0.01 and P = 0.03, respectively); this was also true evaluating the groups PAM with atypia and melanoma all together (P < 0.01). Furthermore, a trend for lower IRS was seen in cases of melanoma without metastasis, with a suggestive pattern of a higher IRS in cases that did develop metastases, supported for CXCR4 using the mouse melanoma metastasis model.

Conclusions

Expression of specific chemokines changes during the progression and metastatic spread of conjunctival melanocytic lesions. Differential chemokine profiles may hold prognostic value for patients with conjunctival melanomas and might be considered as a therapeutic target.

A feed-forward loop between nuclear translocation of CXCR4 and HIF-1α promotes renal cell carcinoma metastasis

CXC chemokine receptor 4 (CXCR4) has been suggested to play a critical role in cancer metastasis. Some studies have described CXCR4 nuclear localization in metastatic lesions of renal cell carcinoma (RCC), which has been suggested to be correlated with cancer metastasis. However, the underlying mechanism and clinical significance of CXCR4 nuclear localization remains unknown. Here, we show that CXCR4 nuclear localization is more likely to occur in RCC tissues, especially in metastases, and is associated with poor prognosis. CXCR4 nuclear localization requires its nuclear localization sequence (NLS, residues 146-RPRK-149). After the mutation of NLS in CXCR4, CXCR4 nuclear localization in RCC cells is lost. Nuclear localization of CXCR4 promoted RCC tumorigenicity both in vitro and in vivo. Mechanistically, we found that CXCR4 and hypoxia-inducible factor-1α (HIF-1α) colocalized in RCC cells and interacted with each other. Moreover, CXCR4 nuclear localization promoted nuclear accumulation of HIF-1α, thereby promoting the expression of genes downstream of HIF-1α. Reciprocally, nuclear HIF-1α promoted CXCR4 transcription, thus forming a feed-forward loop. Subcellular CXCR4 and HIF-1α expression levels were independent adverse prognostic factors and could be combined with TNM stage to generate a predictive nomogram of the clinical outcome of patients with RCC. Therefore, our findings indicate that CXCR4 nuclear translocation plays a critical role in RCC metastasis and may serve as a prognostic biomarker and potential therapeutic target.

Targeting CXC motif chemokine receptor 4 inhibits the proliferation, migration and angiogenesis of lung cancer cells

An increasing volume of data indicates that disrupting the interaction between CXC motif chemokine receptor 4 (CXCR4) and its specific ligand, CXC motif chemokine 12 (CXCL12), may reduce tumor growth and metastasis. However, the translation from bench to bedside must be performed with extreme caution, as the CXCR4/CXCL12 axis is crucial for the normal development and maintenance of tissues and organs. In the present study, Cell Counting Kit-8 and Transwell migration assays were used to detect in vitro proliferation and chemotaxis of CXCR4-expressing A549 cells, a cell strain originating from human non-small-cell lung cancer (NSCLC), with or without the presence of AMD3100, a small-molecule inhibitor specific to CXCR4 signaling. In a xenograft model established by injecting nude mice with A549 cells, tumor growth, CXCR4 expression and microvessel density (MVD) in the tumor mass were determined through tumor size measurements and immunohistochemical staining following intraperitoneal administration of AMD3100 or vehicle. The results demonstrated that CXCR4 blockade inhibited the proliferation of A549 cells and their migration towards CXCL12 in vitro. Tumor growth, CXCR4 expression and MVD were markedly reduced in nude mice treated with AMD3100 compared with mice treated with the vehicle. In conclusion, the present data demonstrated that CXCR4 targeting impaired NSCLC cell growth, angiogenesis and metastatic spread, indicating that it may represent a novel treatment strategy for NSCLC.

Inhibition of CXCL12/CXCR4 axis as a potential targeted therapy of advanced gastric carcinoma

The whole outcome for patients with gastric carcinoma (GC) is very poor because most of them remain metastatic disease during survival even at diagnosis or after surgery. Despite many improvements in multiple strategies of chemotherapy, immunotherapy, and targeted therapy, exploration of novel alternative therapeutic targets is still warranted. Chemokine receptor 4 (CXCR4) and its chemokine ligand 12 (CXCL12) have been identified with significantly elevated levels in various malignancies including GC, which correlates with the survival, proliferation, angiogenesis, and metastasis of tumor cells. Increasing experimental evidence suggests an implication of inhibition of CXCL12/CXCR4 axis as a promising targeted therapy, although there are rare trials focused on the therapeutic efficacy of CXCR4 inhibitors in GC until recently. Therefore, it is reasonable to infer that specific antagonists or antibodies targeting CXCL12/CXCR4 axis alone or combined with chemotherapy will be effective and worthy of further translational studies as a potential treatment strategy in advanced GC.

CXCL12 expression and PD-L1 expression serve as prognostic biomarkers in HCC and are induced by hypoxia

Anti-PD-1 treatment increases anti-tumour immune responses in animal models of hepatocellular carcinoma (HCC). Sorafenib, the mainstay of treatment of HCC patients, however, leads to tumour hypoxia and thereby abrogates the efficacy of anti-PD-1 treatment. This served as a rationale to implement CXCR4 inhibition as adjunct to sorafenib and anti-PD-1 treatment in murine HCC models. We studied the relationship between tumour hypoxia, PD-L1 and CXCL12 expression in human HCC, aiming to test the rationale for triple therapy combining sorafenib, PD-1 immune checkpoint inhibitors and CXCR4 inhibitors. Expression of CXCL12, PD-L1 and of surrogate markers for tumour hypoxia was evaluated at messenger RNA (mRNA) level in a cohort of HCC patients from The Cancer Genome Atlas and immunohistochemically in an independent cohort from the University Hospital of Bonn. Retrospective survival analyses were conducted. CXCL12 mRNA level significantly correlated with markers indicating tumour hypoxia in HCC (HIF1-α ρ = 0.104, p = 0.047). PD-L1 expression was significantly increased in tumours with a high number of tumour-infiltrating lymphocytes (ρ = 0.533, p < 0.001). In Cox proportional hazard analyses, high PD-L1 expression and loss of nuclear CXCL12 expression showed significant prognostic value in terms of overall survival (hazard ratio (HR) = 3.35 [95%CI 1.33-8.46], p = 0.011 for PD-L1; HR = 2.64 [95%CI 1.18-5.88], p = 0.018 for CXCL12, respectively). This study supports the rationale to combine CXCR4 inhibitors and PD-1 immune checkpoint inhibitors in patients with HCC, as sorafenib-induced tumour hypoxia leads to upregulation of PD-L1 and CXCL12.

An optimised mouse model of chronic pancreatitis with a combination of ethanol and cerulein

Introduction

Chronic pancreatitis (CP) is an intractable and multi-factorial disorder. Developing appropriate animal models is an essential step in pancreatitis research, and the best ones are those which mimic the human disorder both aetiologically and pathophysiologically. The current study presents an optimised protocol for creating a murine model of CP, which mimics the initial steps of chronic pancreatitis in alcohol chronic pancreatitis and compares it with two other mouse models treated with cerulein or ethanol alone.

Material and methods

Thirty-two male C57BL/6 mice were randomly selected, divided into four groups, and treated intraperitoneally with saline (10 ml/kg, control group), ethanol (3 g/kg; 30% v/v), cerulein (50 µg/kg), or ethanol + cerulein, for six weeks. Histopathological and immunohistochemical assays for chronic pancreatitis index along with real-time PCR assessments for mRNA levels of inflammatory cytokines and fibrogenic markers were conducted to verify the CP induction.

Results

The results indicated that CP index (CPI) was significantly increased in ethanol-cerulein mice compared to the saline, ethanol, and cerulein groups (p < 0.001). Interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), transforming growth factor β (TGF-β), α-smooth muscle actin (α-SMA), and myeloperoxidase activity were also significantly greater in both cerulein and ethanol-cerulein groups than in the saline treated animals (p < 0.001). Immunohistochemical analysis revealed enhanced expression of TGF-β and α-SMA in ethanol-cerulein mice compared to the saline group.

Conclusions

Intraperitoneal (IP) injections of ethanol and cerulein could successfully induce CP in mice. IP injections of ethanol provide higher reproducibility compared to ethanol feeding. The model is simple, non-invasive, reproducible, and time-saving. Since the protocol mimics the initial phases of CP development in alcoholics, it can be used for investigating basic mechanisms and testing new therapies.

CXCL12 is a key regulator in tumor microenvironment of cervical cancer: an in vitro study

CXCL12 is a small pro-inflammatory chemo-attractant cytokine which signals through chemokine receptor CXCR4. The importance of CXCL12/CXCR4 axis is coming to the fore in several divergent signaling pathway-initiating signals related to cell survival and/or proliferation and cancer metastasis. In the present study we have investigated whether deregulation in CXCR4 signaling (as a consequence of deregulated expression of CXCL12) modulate the metastatic potential of cervical carcinoma cells. We demonstrate that CXCL12 is frequently down regulated and its promoter is hypermethylated in cervical cancer cell lines and primary tumor biopsies. Exogenous treatment of cervical cancer cell lines (HeLa, SiHa and C-33A) with recombinant CXCL12 inhibited the metastasis promoting cell migration, cell invasion and anchorage independent cell growth events. Although this study will need further in vivo validation, our observations suggest that (a) silencing of CXCL12 in cervical cancer cells may be critical in migration and invasion, the key events in cancer cell metastases; (b) cervical cancer cells having down regulated CXCL12 are more prone to being attracted to CXCL12 expressed at secondary sites of metastases; and (c) CXCL12 inhibits anchorage independent cell growth via anoikis. These findings suggest the tumor suppressor functions of CXCL12 in cervical cancer.

A meta-analysis for C-X-C chemokine receptor type 4 as a prognostic marker and potential drug target in hepatocellular carcinoma

Chemokines (CKs), small proinflammatory chemoattractant cytokines that bind to specific G-protein coupled seven-span transmembrane receptors, are major regulators of cell trafficking and adhesion. C-X-C chemokine receptor type 4 (CXCR4) has gained tremendous attention over the last decade, since it was found to be upregulated in a wide variety of cancer types, including hepatocellular carcinoma (HCC). The clinical relevance of expression of CXCR4 in HCC remains controversial; our aim was to identify the precise relationship of CXCR4 to prognosis and clinicopathological features. We searched the database from MEDLINE, PubMed, Web of Science, Scopus and Embase and then conducted a meta-analysis from publications met the inclusion criteria for the qualitative study. Our data showed that 1) CXCR4 is overexpressed in HCC tissues but not in normal hepatic tissue, OR =84.26, 95% confidence interval (CI) =11.86–598.98, P<0.0001. CXCR4 expression is higher in HCC than those in cirrhosis as well, OR =20.71, 95% CI =7.61–56.34, P<0.00001. 2) The expression levels of CXCR4 does not increase during local progression, however, CXCR4 expression increases the risk of distant metastases in HCC, OR =5.84, 95% CI =2.84–12.00, P<0.00001. 3) High levels of CXCR4 gene expression are associated with worse survival in HCC, HR =0.18, 95% CI =0.10–0.32, Z=5.77, P<0.00001. These data indicate that CXCR4 expression correlates with an increased risk and worse survival in HCC patients. The aberrant CXCR4 expression plays an important role in the carcinogenesis and metastasis of HCC. Our conclusion also supports that the promise of CXCR4 signaling pathway blockade as a potential strategy for HCC patients.

Epigenetic silencing of CXCR4 promotes loss of cell adhesion in cervical cancer

In the network of chemokine signaling pathways, recent reports have described the SDF-1α/CXCR4 axis and its role in cancer progression and metastasis. Interestingly, we found downregulation of CXCR4 at both transcript and protein level in cervical cancer cell lines and primary tumors. We also found CXCR4 promoter hypermethylation in cervical cancer cell lines and primary biopsy samples. DNA hypomethylating drug 5-AZA-2′-deoxycytidine and histone deacetylase inhibitor Trichostatin A treatments in cell lines reactivate both CXCR4 transcription and protein expression. Cell adhesion assay demonstrated that autocrine SDF-1α promotes the loss of cell adhesion while paracrine SDF-1α predominantly protects the normal cervical cells from loss of cell adhesion. Cervical cancer cell line C-33A having increased expression of CXCR4 after TSA treatment showed increased cell adhesion by paracrine source of SDF-1α in comparison to untreated C-33A. These findings demonstrate the first evidence that epigenetic silencing of CXCR4 makes the cells inefficient to respond to the paracrine source of SDF-1α leading to loss of cell adhesion, one of the key events in metastases and progression of the disease. Our results provide novel insight of SDF-1α/CXCR4 signaling in tumor microenvironment which may be promising to further delineate molecular mechanism of cervical carcinogenesis.