CXCR4--A Prognostic and Clinicopathological Biomarker for Pancreatic Ductal Adenocarcinoma: A Meta-Analysis

Stem cell-like circulating tumor cells identified by Pep@MNP and their clinical significance in pancreatic cancer metastasis

Objective

The circulating tumor cells (CTCs) could be captured by the peptide functionalized magnetic nanoparticles (Pep@MNP) detection system in pancreatic ductal adenocarcinoma (PDAC). CTCs and the CXCR4 expression were detected to explore their clinical significance. The CXCR4+ CTCs, this is highly metastatic-prone stem cell-like subsets of CTCs (HM-CTCs), were found to be associated with the early recurrence and metastasis of PDAC.

Methods

CTCs were captured by Pep@MNP. CTCs were identified via immunofluorescence with CD45, cytokeratin antibodies, and the CXCR4 positive CTCs were assigned to be HM-CTCs.

Results

The over-expression of CXCR4 could promote the migration of pancreatic cancer cell in vitro and in vivo. In peripheral blood (PB), CTCs were detected positive in 79.0% of all patients (49/62, 9 (0-71)/2mL), among which 63.3% patients (31/49, 3 (0-23)/2mL) were HM-CTCs positive. In portal vein blood (PVB), CTCs were positive in 77.5% of patients (31/40, 10 (0-40)/2mL), and 67.7% of which (21/31, 4 (0-15)/2mL) were HM-CTCs positive CTCs enumeration could be used as diagnostic biomarker of pancreatic cancer (AUC = 0.862), and the combination of CTCs positive and CA19-9 increase shows improved diagnostic accuracy (AUC = 0.963). in addition, PVB HM-CTCs were more accurate to predict the early recurrence and liver metastasis than PB HM-CTCs (AUC 0.825 vs. 0.787 and 0.827 vs. 0.809, respectively).

Conclusions

The CTCs identified by Pep@MNP detection system could be used as diagnostic and prognostic biomarkers of PDAC patients. We identified and defined the CXCR4 over-expressed CTC subpopulation as highly metastatic-prone CTCs, which was proved to identify patients who were prone to suffering from early recurrence and metastasis.

Impact of CXCR4-Directed PET/CT on Staging and Proposed Oncologic Management in Patients With Digestive System Tumors

PURPOSE

To elucidate the influence of CXC motif chemokine receptor 4 (CXCR4)-directed imaging on staging and proposed oncologic management in patients with digestive system tumors compared with guideline-appropriate imaging (GAI).

METHODS

From our PET/CT database, we retrospectively identified 37 patients with advanced digestive system tumors, which had been scheduled for CXCR4-targeted [ 68 Ga]Ga-pentixafor PET/CT for potential theranostic considerations. In all subjects, concurrent GAI was also available. Patients were afflicted with gastroenteropancreatic neuroendocrine neoplasms (21/37 [56.8%]), pancreatic duct adenocarcinoma (6/37 [16.2%]), cholangiocarcinoma (5/37 [13.5%]), hepatocellular carcinoma (4/37 [10.8%]), and colorectal carcinoma (1/37 [2.7%]). Staging results and impact on proposed oncologic management by a board-certified gastroenterologist were compared between GAI and [ 68 Ga]Ga-pentixafor PET/CT.

RESULTS

Relative to GAI, CXCR4-directed PET/CT resulted in staging changes in 14 of 37 patients (37.8%). Upstaging was seen in 1 of 14 patients (7.1%), whereas downstaging was recorded in the remaining 13 of 14 patients (92.9%). Among those, staging changes would not have triggered any changes in oncological management in 4 of 14 (28.6%). For the remaining 10 of 14 patients (71.4%), however, findings on [ 68 Ga]Ga-pentixafor PET/CT would have impacted subsequent clinical algorithm, including the necessity for further diagnostic steps or failure to initiate antitumor therapy.

CONCLUSION

[ 68 Ga]Ga-pentixafor PET/CT missed tumor lesions in 13 patients with digestive system tumors, which would have led to inappropriate downstaging and clinical treatment of 10 patients. As such, our results do not support a more widespread use of [ 68 Ga]Ga-pentixafor PET/CT for clinical staging in those tumor entities.

Tissue-resident CXCR4+ macrophage as a poor prognosis signature promotes pancreatic ductal adenocarcinoma progression

Macrophage is an essential part of the tumor immune microenvironment of pancreatic ductal adenocarcinoma. In our study, we explored the CXCR4⁺ macrophages subset on its prognosis value, immune profile and distinct function in pancreatic cancer progression. Specimens from 102 postoperative pancreatic patients were analyzed by flow cytometry or immune-fluorescence, and the prognostic value of CXCR4⁺ macrophages infiltration was further determined by Cox regression. In silico analysis on TCGA, ICGC database and single-cell sequencing of pancreatic ductal adenocarcinoma further validated our findings. We found that high CXCR4⁺ macrophages infiltration was associated with poor overall survival (P < .01) and disease-free survival (P < .05) as an independent factor. CXCR4⁺ macrophages exhibited an M2 protumor phenotype with high expression of CD206. The function of CXCR4⁺ macrophages was further analyzed in the murine orthotopic PDAC model with its tumor promotion effect and inhibition of CD8⁺ T cells. Mechanistic and RNA-seq analysis showed that CXCR4⁺ macrophages participated in extracellular matrix remodeling procedures and especially secreted SPARC through CXCR4/PI3K/Akt pathway promoting tumor proliferation and migration. Our study reveals that CXCR4⁺ macrophages infiltration is an indicator of poor prognosis of PDAC and targeting these cells was potentially crucial in immunotherapy of PDAC.

Multi-omic Characterization of Pancreatic Ductal Adenocarcinoma Relates CXCR4 mRNA Expression Levels to Potential Clinical Targets

PURPOSE

Chemokines are essential for immune cell trafficking and are considered to have a major impact on the composition of the tumor microenvironment. CX-chemokine receptor 4 (CXCR4) is associated with poor differentiation, metastasis, and prognosis in pancreatic ductal adenocarcinoma (PDAC). This study provides a comprehensive molecular portrait of PDAC according to CXCR4 mRNA expression levels.

EXPERIMENTAL DESIGN

The Cancer Genome Atlas database was used to explore molecular and immunologic features associated with CXCR4 mRNA expression in PDAC. A large real-word dataset (n = 3,647) served for validation and further exploratory analyses. Single-cell RNA analyses on a publicly available dataset and in-house multiplex immunofluorescence (mIF) experiments were performed to elaborate cellular localization of CXCR4.

RESULTS

High CXCR4 mRNA expression (CXCR4high) was associated with increased infiltration of regulatory T cells, CD8+ T cells, and macrophages, and upregulation of several immune-related genes, including immune checkpoint transcripts (e.g., TIGIT, CD274, PDCD1). Analysis of the validation cohort confirmed the CXCR4-dependent immunologic TME composition in PDAC irrespective of microsatellite instability-high/mismatch repair-deficient or tumor mutational burden. Single-cell RNA analysis and mIF revealed that CXCR4 was mainly expressed by macrophages and T-cell subsets. Clinical relevance of our finding is supported by an improved survival of CXCR4high PDAC.

CONCLUSIONS

High intratumoral CXCR4 mRNA expression is linked to a T cell- and macrophage-rich PDAC phenotype with high expression of inhibitory immune checkpoints. Thus, our findings might serve as a rationale to investigate CXCR4 as a predictive biomarker in patients with PDAC undergoing immune checkpoint inhibition.

Current Status of 68Ga-Pentixafor in Solid Tumours

Chemokine receptor CXCR4 is overexpressed in neoplasms and its expression is related to tumour invasion, metastasis and aggressiveness. ⁶⁸Ga-Pentixafor is used to non-invasively image the expression of CXCR4 in tumours and has been widely used in haematological malignancies. Recent evidence shows that therapies targeting CXCR4 can increase the chemosensitivity of the tumour as well as inhibit tumour metastasis and aggressiveness. ⁶⁸Ga-Pentixafor has shown promise as an elegant radiotracer to aid in the selection of patients whose tumours demonstrate CXCR4 overexpression and who therefore may benefit from novel therapies targeting CXCR4. In addition, its therapeutic partners ¹⁷⁷Lu- and ⁹⁰Y-Pentixather have been investigated in the treatment of patients with advanced haematological malignancies, and initial studies have shown a good treatment response in metabolically active lesions. ⁶⁸Ga-Pentixafor in solid tumours complements ¹⁸F-FDG by providing prognostic information and selecting patients who may benefit from therapies targeting CXCR4. This review summarises the available literature on the potential applications of ⁶⁸Ga-Pentixafor in solid tumours.

Envisioning the immune system to determine its role in pancreatic ductal adenocarcinoma: Culprit or victim?

Pancreatic ductal adenocarcinoma has a poor 5-year survival rate that makes it one of the most fatal human malignancies. Unfortunately, despite the serious improvement in the survival of most cancers, there has been a minor advance in pancreatic cancer (PC). Major advances in PC treatment have been assessed over the bygone twenty-year time span, yet some complications make the survival of the patients shorter. Getting to know the PC tumor microenvironment (TME) and the immunosuppression that happens during the pathogenesis of this malignancy could be a great help to understand the nature of the immune system and find better treatment modalities based on it. Although many immune cells are present in PC, immunosuppression of the TME leads to severe immune dysfunction in the patients, therefore immune effectors fail to do their functions. Lately, immunotherapy has been presented as one of the promising treatment strategies for different malignancies including hepatocellular carcinoma, melanoma, non-small cell lung cancer, and kidney cancer. In PC, there has been shown promising results centered around the TME, immune checkpoint inhibitors, cancer vaccines, and other approaches especially when used as combinational therapy. Here we dig a little deeper into the role of the immune system and possible therapeutic options in the treatment of PC.

An Emerging Role for the Unfolded Protein Response in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic cancer and one of the leading causes of cancer-associated deaths in the world. It is characterised by dismal response rates to conventional therapies. A major challenge in treatment strategies for PDAC is the presence of a dense stroma that surrounds the tumour cells, shielding them from treatment. This unique tumour microenvironment is fuelled by paracrine signalling between pancreatic cancer cells and supporting stromal cell types including the pancreatic stellate cells (PSC). While our molecular understanding of PDAC is improving, there remains a vital need to develop effective, targeted treatments. The unfolded protein response (UPR) is an elaborate signalling network that governs the cellular response to perturbed protein homeostasis in the endoplasmic reticulum (ER) lumen. There is growing evidence that the UPR is constitutively active in PDAC and may contribute to the disease progression and the acquisition of resistance to therapy. Given the importance of the tumour microenvironment and cytokine signalling in PDAC, and an emerging role for the UPR in shaping the tumour microenvironment and in the regulation of cytokines in other cancer types, this review explores the importance of the UPR in PDAC biology and its potential as a therapeutic target in this disease.

The prognostic and diagnostic values of MicroRNA-10b in gastric cancer: A comprehensive study based on meta-analysis and TCGA database

We conducted a study to evaluate the prognostic and diagnostic values of microRNA-10b (miR-10b) in gastric cancer (GC) based on meta-analysis and TCGA database. Relevant studies were searched in English and Chinese database and meta-analysis was conducted on Stata 12.0. The expression value of miR-10b and clinical parameters of GC patients were downloaded from TCGA database, and relevant analyses were conducted on SPSS. High expression of miR-10b was linked with unfavorable overall survival (OS) in GC (HR = 1.572, 95% CI: 1.240-1.992, P < .001). However, the meta-analysis was significant for patients in early stage, but not for patients in advanced stage. The expression of miR-10b-3p was significantly lower in cancer tissue compared with adjacent tissue (P < .001). Meanwhile, the area under the ROC curve (AUC) value was 0.652 (0.562-0.742), P = .001. Disease-free survival analysis showed increasing miR-10b-5p was correlated with worse survival outcome (HR = 2.366, 95% CI: 1.414-3.959, P = .001). In conclusion, miR-10b acts as a tumor suppressor with prognostic and diagnostic values for GC.

The Impact of MicroRNA-133a on Prognosis and Clinicopathological Parameters for Digestive System Cancers: a Comprehensive Study Based on Meta-Analysis and TCGA Database

We conducted a meta-analysis on the impact of microRNA-133a (miR-133a) on digestive system cancers, and verified the results through The Cancer Genome Atlas (TCGA). Relevant studies were searched in English and Chinese database and meta-analysis was performed using Stata 12.0. The corresponding information of miR-133a and digestive system cancers were obtained from TCGA database and analysis was performed using SPSS. Increased miR-133a expression was linked with favorable overall survival (OS) in digestive system cancers (HR = 0.539, 95% CI: 0.416-0.698, P < 0.001), digestive tract cancers (HR =0.558, 95% CI: 0.406-0.767, P < 0.001), esophageal squamous cell carcinoma (ESCC) (HR = 0.427, 95% CI: 0.265-0.690, P = 0.001) and gastric cancer (HR = 0.541, 95% CI: 0.385-0.761, P < 0.001). The expression of miR-133a was significantly lower in cancer tissue compared with adjacent tissue for ESCC (P < 0.001), gastric cancer (P < 0.001), colorectal cancer (P < 0.001) and hepatocellular carcinoma (P = 0.002). Meanwhile, the area under the ROC curve (AUC) value for miR-133a was 0.836, 0.888, and 0.99 in ESCC, gastric cancer and colorectal cancer. MiR-133a is a tumor suppressor with prognostic and diagnostic values for digestive system cancers. High miR-133a expression was associated with better prognosis and less adverse clinicopathological parameters. More research should be performed to test these findings.

CXCR4/CXCR7/CXCL12-Axis in Follicular Thyroid Carcinoma

Background: Follicular thyroid carcinoma's (FTC) often benign course is partially due to adjuvant radioactive iodine (RAI) treatment. However, once the tumour has spread and fails to retain RAI, the therapeutic options are limited and the outcome is poor. In this subset of patients, the identification of novel druggable biomarkers appears invaluable. Here, we investigated the stage dependent expression and functional role of the C-X-C chemokine receptors type 4 and 7 (CXCR4/7) in FTC.

Methods: CXCR4/7 expression was examined in 44 FTC and corresponding non-neoplastic thyroid specimens as well as 10 FTC distant metastases and 18 follicular adenomas using tissue microarray technology. Expression levels were correlated with clinicopathological variables as well as overall and recurrence free survival. Changes regarding cell cycle activation, tumour cell invasiveness and mRNA expression of genes related to epithelial-mesenchymal transition (EMT) were investigated after treatment with recombinant human SDF1α/CXCL12 (rh-SDF1α) and CXCR4 antagonists AMD3100 and WZ811.

Results: CXCR4/7 expression was associated with large tumour size, advanced UICC stage as well as shorter overall and recurrence free survival. CXCR4 was significantly higher expressed in distant metastases than in primary tumour cores. In addition, rh-SDF1α induced invasive growth, cell cycle activation and EMT, while CXCR4 antagonists significantly reduced FTC invasiveness in vitro.

Conclusion: Here we provide first evidence of the biological importance of the CXCR4/CXCR7/CXCL12 axis in FTC. Our findings underscore the therapeutic potential of this chemokine receptor family in advanced FTC and offer new valuable insight into the oncogenesis of metastatic FTC.

PTEN expression is a prognostic marker for patients with non-small cell lung cancer: a systematic review and meta-analysis of the literature

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a known tumor suppressor in non-small cell lung cancer (NSCLC). By performing a systematic review and meta-analysis of the literature, we determined the prognostic value of decreased PTEN expression in patients with NSCLC. We comprehensively and systematically searched through multiple online databases up to May 22, 2016 for NSCLC studies reporting on PTEN expression and patient survival outcome. Several criteria, including the Newcastle-Ottawa Quality Assessment Scale (NOS), were used to discriminate between studies. In total, 23 eligible studies with a total of 2,505 NSCLC patients were included in our meta-analysis. Our results demonstrated that decreased expression of PTEN correlated with poor overall survival in NSCLC patients and was indicative of a poor prognosis for disease-free survival and progression-free survival in patients with NSCLC.

Strategies for Increasing Pancreatic Tumor Immunogenicity

Immunotherapy has changed the standard of care for multiple deadly cancers, including lung, head and neck, gastric, and some colorectal cancers. However, single-agent immunotherapy has had little effect in pancreatic ductal adenocarcinoma (PDAC). Increasing evidence suggests that the PDAC microenvironment is comprised of an intricate network of signals between immune cells, PDAC cells, and stroma, resulting in an immunosuppressive environment resistant to single-agent immunotherapies. In this review, we discuss differences between immunotherapy-sensitive cancers and PDAC, the complex interactions between PDAC stroma and suppressive tumor-infiltrating cells that facilitate PDAC development and progression, the immunologic targets within these complex networks that are druggable, and data supporting combination drug approaches that modulate multiple PDAC signals, which should lead to improved clinical outcomes. Clin Cancer Res; 23(7); 1656-69. ©2017 AACRSee all articles in this CCR Focus section, "Pancreatic Cancer: Challenge and Inspiration."

Mechanisms by which CXCR4/CXCL12 cause metastatic behavior in pancreatic cancer

C-X-C motif chemokine receptor (CXCR) 4/CXCL12 is associated with tumor invasion and metastasis in pancreatic cancer. The present study aimed to investigate the possible mechanisms behind this process by studying the association between the expression of CXCR4 and numerous molecular markers. A total of 60 patients with pancreatic cancer who had been treated with radical surgery between July 2012 and February 2016 were included in the present study. The expression of CXCR4/CXCL12 in primary pancreatic cancer lesions, tissues adjacent to cancerous tissue, non-cancerous pancreatic tissues and in the surrounding lymph nodes was evaluated by immunohistochemistry. Expression levels of four candidate biomarkers [vascular endothelial growth factor-C (VEGF-C), Ki-67, matrix metalloproteinase 2 (MMP-2) and β-catenin] were also evaluated. The correlation between CXCR4 and these four biomarkers was assessed. CXCR4 (CXCL12) expression levels were higher in pancreatic cancer 56.7% (86.7%), paracancerous tissue 50.0% (85.0%) and surrounding lymph nodes 53.3% (80.0%), compared with in normal tissues 18.3% (45.0%). CXCR4 expression was significantly associated with the lymph node metastasis of tumors (P=0.001), pathological type (P=0.037) and tumor-node-metastasis stage (P=0.031). CXCR4 expression exhibited a positive correlation with VEGF-C (r=0.417; P=0.001), Ki-67 (r=0.316; P=0.014), MMP-2 (r=0.284; P=0.028) and β-catenin (r=0.368; P=0.04). Furthermore, logistic regression analysis revealed VEGF-C (β=1.722; P=0.005) and Ki-67 (β=1.196; P=0.047) to be two biomarkers that cause metastasis via CXCR4. CXCR4/CXCL12 is closely associated with tumor grade and lymphatic metastasis. VEGF-C and Ki-67 are two important biomarkers, through which CXCR4 initiates metastatic behavior in pancreatic cancer. Therefore, angiogenesis inhibitors will continue to be effective agents in treating pancreatic cancer.

Pediatric sarcomas

Sarcomas arise from primitive mesenchymal cells, which are classified, into two main groups: Bone and soft tissue sarcomas. We have searched all-important electronic databases including Google scholar and PubMed for the collection of latest literature pertaining to pediatric sarcomas. Latest literature confirmed that these tumors are relatively rare and represent only 1% of all malignancies but they have higher incidence in children. Pediatric sarcomas comprise about 13% of all pediatric malignancies and are ranked third in childhood cancers. The highest incidence rates are reported among rhabdomyosarcoma, osteosarcoma and Ewing's sarcomas in children. All of these neoplasms often display highly aggressive behavior with tendency to form metastases. Important globally used management avenues include surgery with systemic chemotherapy and have success rate of 70% at 5-years. Furthermore, in the cases of advanced stages, the prognosis is poor, chances of treatment failure and recurrence are quite high. Utilization of cancer stem cells is the latest approach with great potential in management of above pathological state. The present review article discuss all-important aspects of commonly found pediatric sarcomas throughout the world.

CXCR4/CXCR7/CXCL12 axis promotes an invasive phenotype in medullary thyroid carcinoma

Background:

Medullary thyroid carcinoma (MTC) is a rare and challenging endocrine malignancy. Once spread, the therapeutic options are limited and the outcome poor. For these patients, the identification of new druggable biological markers is of great importance. Here, we investigated the prognostic and biological role of the C-X-C chemokine receptors type 4 and 7 (CXCR4/7) in MTC.

Methods:

Eighty-six MTC and corresponding non-neoplastic thyroid specimens were immunohistochemically stained for CXCR4/7 using tissue microarray technology and expression levels correlated with clinicopathological variables. Medullary thyroid carcinoma cell line TT was treated with recombinant human SDF1α/CXCL12 (rh-SDF1α) and CXCR4 antagonists AMD3100 and WZ811. Changes in cell cycle activation, tumour cell invasiveness as well as changes in mRNA expression levels of genes associated with epithelial–mesenchymal transition (EMT) were investigated.

Results:

High CXCR4 expression was associated with large tumour size and metastatic disease. CXCR4 antagonists significantly reduced tumour cell invasiveness, while the treatment with rh-SDF1α stimulated invasive growth, caused cell cycle activation and induced EMT.

Conclusions:

The CXCR4/CXCR7/CXCL12 axis plays an important role in MTC. We provide first evidence that the chemokine receptors might serve as potential therapeutic targets in patients with advanced MTC and offer new valuable insight into the underlying molecular machinery of metastatic MTC.

"Stealth dissemination" of macrophage-tumor cell fusions cultured from blood of patients with pancreatic ductal adenocarcinoma

Here we describe isolation and characterization of macrophage-tumor cell fusions (MTFs) from the blood of pancreatic ductal adenocarcinoma (PDAC) patients. The MTFs were generally aneuploidy, and immunophenotypic characterizations showed that the MTFs express markers characteristic of PDAC and stem cells, as well as M2-polarized macrophages. Single cell RNASeq analyses showed that the MTFs express many transcripts implicated in cancer progression, LINE1 retrotransposons, and very high levels of several long non-coding transcripts involved in metastasis (such as MALAT1). When cultured MTFs were transplanted orthotopically into mouse pancreas, they grew as obvious well-differentiated islands of cells, but they also disseminated widely throughout multiple tissues in "stealth" fashion. They were found distributed throughout multiple organs at 4, 8, or 12 weeks after transplantation (including liver, spleen, lung), occurring as single cells or small groups of cells, without formation of obvious tumors or any apparent progression over the 4 to 12 week period. We suggest that MTFs form continually during PDAC development, and that they disseminate early in cancer progression, forming "niches" at distant sites for subsequent colonization by metastasis-initiating cells.

Chloroquine-Modified Hydroxyethyl Starch as a Polymeric Drug for Cancer Therapy

Hydroxyethyl starch (HES) is a clinically used polysaccharide colloidal plasma volume expander. The goal of this study was to synthesize HES modified with hydroxychloroquine (HCQ) as a novel polymeric drug with the ability to inhibit the invasive character of pancreatic cancer (PC) cells. HES was conjugated with HCQ using a simple carbonyldiimidazole coupling to prepare Chloroquine-modified HES (CQ-HES). CQ-HES with various degrees of HCQ substitution were synthesized and characterized. Atomic force microscopy was used to demonstrate a pH-dependent assembly of CQ-HES into well-defined nanoparticles. In vitro studies in multiple PC cell lines showed CQ-HES to have a similar toxicity profile as HCQ. Confocal microscopy revealed the propensity of CQ-HES to localize to lysosomes and mechanistic studies confirmed the ability of CQ-HES to inhibit autophagy in PC cells. Further studies demonstrated a greatly enhanced ability of CQ-HES to inhibit the migration and invasion of PC cells when compared with HCQ. The enhanced inhibitory actions of CQ-HES compared to HCQ appeared to arise in part from the increased inhibition of ERK and Akt phosphorylation. We found no significant HCQ release from CQ-HES, which confirmed that the observed activity was due to the action of CQ-HES as a polymeric drug. Due to its promising ability to block cancer cell invasion and the ability to form nanoparticles, CQ-HES has the potential as a drug delivery platform suitable for future development with chemotherapeutics to establish novel antimetastatic treatments.

Screening of cancer tissue arrays identifies CXCR4 on adrenocortical carcinoma: correlates with expression and quantification on metastases using 64Cu-plerixafor PET

Expression of the chemokine receptor CXCR4 by many cancers correlates with aggressive clinical behavior. As part of the initial studies in a project whose goal was to quantify CXCR4 expression on cancers non-invasively, we examined CXCR4 expression in cancer samples by immunohistochemistry using a validated anti-CXCR4 antibody. Among solid tumors, we found expression of CXCR4 on significant percentages of major types of kidney, lung, and pancreatic adenocarcinomas, and, notably, on metastases of clear cell renal cell carcinoma and squamous cell carcinoma of the lung. We found particularly high expression of CXCR4 on adrenocortical cancer (ACC) metastases. Microarrays of ACC metastases revealed correlations between expression of CXCR4 and other chemokine system genes, particularly CXCR7/ACKR3, which encodes an atypical chemokine receptor that shares a ligand, CXCL12, with CXCR4. A first-in-human study using ⁶⁴Cu-plerixafor for PET in an ACC patient prior to resection of metastases showed heterogeneity among metastatic nodules and good correlations among PET SUVs, CXCR4 staining, and CXCR4 mRNA. Additionally, we were able to show that CXCR4 expression correlated with the rates of growth of the pulmonary lesions in this patient. Further studies are needed to understand better the role of CXCR4 in ACC and whether targeting it may be beneficial. In this regard, non-invasive methods for assessing CXCR4 expression, such as PET using ⁶⁴Cu-plerixafor, should be important investigative tools.

Emerging roles of the CXCL12/CXCR4 axis in pancreatic cancer progression and therapy

Chemokine networks regulate a variety of cellular, physiological, and immune processes. These normal functions can become appropriated by cancer cells to facilitate a more hospitable niche for aberrant cells by enhancing growth, proliferation, and metastasis. This is especially true in pancreatic cancer, where chemokine signaling is a vital component in the development of the supportive tumor microenvironment and the signaling between the cancer cells and surrounding stromal cells. Although expression patterns vary among cancer types, the chemokine receptor CXCR4 has been implicated in nearly every major malignancy and plays a prominent role in pancreatic cancer development and progression. This receptor, in conjunction with its primary chemokine ligand CXCL12, promotes pancreatic cancer development, invasion, and metastasis through the management of the tumor microenvironment via complex crosstalk with other pathways. Thus, CXCR4 likely contributes to the poor prognoses observed in patients afflicted with this malignancy. Recent exploration of combination therapies with CXCR4 antagonists have demonstrated improved outcomes, and abolishing the contribution of this pathway may prove crucial to effectively treat pancreatic cancer at both the primary tumor and metastases.

Genetic polymorphisms associated with pancreatic cancer survival: a genome-wide association study

Previous findings on the association of genetic factors and pancreatic cancer survival are limited and inconsistent. In a two-stage study, we analyzed the existing genome-wide association study dataset of 868 pancreatic cancer patients from MD Anderson Cancer Center in relation to overall survival using Cox regression. Top hits were selected for replication in another 820 patients from the same institution using the Taqman genotyping method. Functional annotation, pathway analysis and gene expression analysis were conducted using existing software and databases. We discovered genome-wide significant associations of patient survival with three imputed SNPs which, in complete LD (r²  = 1), were intronic SNPs of the PAIP2B (rs113988120) and DYSF genes (rs112493246 and rs138529893) located on Chromosome 2. The variant alleles were associated with a 3.06-fold higher risk of death [95% confidence interval (CI) = 2.10-4.47, p=6.4 × 10-9] after adjusting for clinical factors. Eleven SNPs were tested in the replication study and the association of rs113988120 with survival was confirmed (hazard ratio: 1.57, 95% CI: 1.13-2.20,  p=0.008). In silico analysis found rs1139988120 might lead to altered motif. This locus is in LD (D' = 0.77) with three eQTL SNPs near or belong to the NAGK and MCEE genes. According to The Cancer Genome Atlas data and our previous RNA-sequencing data, the mRNA expression level of PAIP2B but not NAGK, MCEE or DYSF was significantly lower in pancreatic tumors than in normal adjacent tissues. Additional validation efforts and functional studies are warranted to demonstrate whether PAIP2B is a novel tumor suppressor gene and a potential therapeutic target for pancreatic cancer.

Sulfatase-2: a prognostic biomarker and candidate therapeutic target in patients with pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is the fifth most common cause of cancer death in the UK. Its poor prognosis is attributed to late detection and limited therapeutic options. Expression of SULF2, an endosulfatase that modulates heparan sulfate proteoglycan 6-O-sulfation and is reportedly tumourigenic in different types of cancer, was investigated.

METHODS

SULF2 expression was determined immunohistochemically in archival surgical resection tissue sections from 93 patients with a confirmed histological diagnosis of PDAC between 2002 and 2008 followed for a median of 9 years. Relationships with clinico-pathological parameters and patient survival were explored.

RESULTS

The majority of PDACs showed positive SULF2 staining in tumour cells and intratumoural or tumour-adjacent stroma. Greater than 25% SULF2-positive tumour cells was present in 60% of cancers and correlated with tumour stage (P=0.002) and perineural invasion (P=0.024). SULF2 intensity was scored moderate or strong in 81% of cancers and positively correlated with vascular invasion (P=0.015). High SULF2 expression, defined as >50% SULF2-positive tumour cells and strong SULF2 staining, was associated with shorter time to radiological progression (P=0.018, HR 1.98, CI 1.13-3.47). Similarly, by multivariate analysis, high SULF2 expression was independently associated with poorer survival (P=0.004, HR 2.10, CI 1.26-3.54), with a median survival of 11 months vs 21 months for lower PDAC SULF2.

CONCLUSIONS

Elevated SULF2 in PDAC was associated with advanced tumour stage, vascular invasion, shorter interval to radiological progression and shorter overall survival. SULF2 may have roles as a prognostic biomarker and as a therapeutic target for patients with PDAC.

Prognostic value of decreased microRNA-133a in solid cancers: a meta-analysis

OBJECTIVE

Increasing evidence indicates that the decreased expression of microRNA-133a (miR-133a) may be correlated with poor survival for cancer patients. Thus, we performed this meta-analysis to evaluate the prognostic value of decreased miR-133a in solid cancers.

METHODS

Eligible studies were gathered by searching on PubMed, Web of Science, and Embase. Using the STATA 12.0 software, the pooled hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) for total and subgroup analyses were calculated to investigate the possible correlation between decreased miR-133a and overall survival (OS) of patients with cancer.

RESULTS

Ten studies were enrolled in this meta-analysis. The pooled result showed that decreased expression of miR-133a predicted poor OS in solid cancer patients (HR =1.62, 95% CI: 1.16-2.24, P=0.004). Compared with the total pooled HR, further analyses indicated that the subgroups of digestive system neoplasms (HR =1.73, 95% CI: 1.20-2.51, P=0.003), frozen tissue preservation (HR =1.89, 95% CI: 1.41-2.53, P<0.001), and multivariate analysis (HR =2.07, 95% CI: 1.42-3.02, P<0.001) exhibited stronger connection between decreased miR-133a expression and OS outcome.

CONCLUSION

This meta-analysis suggested that decreased miR-133a was associated with poor OS in patients with solid cancer. Because of the data in our study are limited, additional studies are required to verify the poor prognosis of decreased miR-133a in solid tumors.

Cytokine Regulation of Metastasis and Tumorigenicity

The human body combats infection and promotes wound healing through the remarkable process of inflammation. Inflammation is characterized by the recruitment of stromal cell activity including recruitment of immune cells and induction of angiogenesis. These cellular processes are regulated by a class of soluble molecules called cytokines. Based on function, cell target, and structure, cytokines are subdivided into several classes including: interleukins, chemokines, and lymphokines. While cytokines regulate normal physiological processes, chronic deregulation of cytokine expression and activity contributes to cancer in many ways. Gene polymorphisms of all types of cytokines are associated with risk of disease development. Deregulation RNA and protein expression of interleukins, chemokines, and lymphokines have been detected in many solid tumors and hematopoetic malignancies, correlating with poor patient prognosis. The current body of literature suggests that in some tumor types, interleukins and chemokines work against the human body by signaling to cancer cells and remodeling the local microenvironment to support the growth, survival, and invasion of primary tumors and enhance metastatic colonization. Some lymphokines are downregulated to suppress tumor progression by enhancing cytotoxic T cell activity and inhibiting tumor cell survival. In this review, we will describe the structure/function of several cytokine families and review our current understanding on the roles and mechanisms of cytokines in tumor progression. In addition, we will also discuss strategies for exploiting the expression and activity of cytokines in therapeutic intervention.

Prognostic value of decreased FOXP1 protein expression in various tumors: a systematic review and meta-analysis

The prognostic value of forkhead box protein P1 (FOXP1) protein expression in tumors remains controversial. Therefore, we conducted a systematic review and meta-analysis, searching the PubMed, Embase and Web of Science databases to identify eligible studies. In total, we analyzed 22 articles that examined 9 tumor types and included 2468 patients. Overall, decreased expression of FOXP1 protein was associated with favorable overall survival (OS) in lymphoma patients (HR = 0.38, 95%CI: 0.30–0.48, p < 0.001). In patients with solid tumors, decreased FOXP1 expression correlated with unfavorable OS (HR = 1.82, 95%CI: 1.18–2.83, p = 0.007). However, when FOXP1 protein expression was nuclear, decreased expression was also associated with favorable OS (HR = 0.53, 95%CI: 0.32–0.86, p = 0.011). Furthermore, decreased FOXP1 expression resulted in the best OS in patients with mucosa-associated lymphoid tissue (MALT) lymphomas (HR = 0.26, 95%CI: 0.11–0.59, p = 0.001), but the worst OS was observed in non-small cell lung cancer (NSCLC) patients (HR = 3.11, 95%CI: 1.87–5.17, p < 0.001). In addition, decreased FOXP1 expression was significantly correlated with an unfavorable relapse-free survival (RFS) in breast cancer patients (HR = 1.93, 95%CI: 1.33–2.80, p = 0.001).

COMMD7 functions as molecular target in pancreatic ductal adenocarcinoma

Our previous studies provided evidence that COMMD7 was associated with tumor progression in human solid cancer. Herein, we aimed to investigate its expression pattern, clinical significance, and biological function in pancreatic ductal adenocarcinoma (PDAC). We found that high COMMD7 expression was specifically detected in PDAC tissues and PDAC cell lines. In addition, COMMD7 overexpression positively correlated with histological differentiation and tumor node metastasis (TNM) stage. Patients with high COMMD7 expression had significantly poorer overall survival, and high COMMD7 expression was an independent predictor of poor prognosis. To further explore the regulatory mechanism of COMMD7, we used stable short hairpin RNA (shRNA)-mediated knockdown and divided the work into in vitro and in vivo experiments. In vitro, the anti-proliferation effects of COMMD7 inhibition were observed under long-time stress conditions, which correlated with cyclin D1 and Bcl-2 downregulation and Bax upregulation. We found that under short-time stress conditions, decreased COMMD7 expression also inhibited PDAC cell invasion in vitro which decreased the secretion of matrix metalloproteinase 2 (MMP-2). Moreover, extracellular signal-regulated kinase1/2 (ERK1/2) was identified as a direct target of COMMD7. The inhibition of ERK1/2 activity under short- or long-time stress conditions using specific inhibitors in COMMD7 inhibition cells all exhibited a strong tumorigenic role. In vivo, COMMD7 was sufficient to impair tumor growth. Our results suggest that COMMD7 plays an important role in the late progression of PDAC and is a potential novel target. © 2016 Wiley Periodicals, Inc.

The Prognostic Value of Decreased LKB1 in Solid Tumors: A Meta-Analysis

Background

Liver kinase B1 (LKB1) is a protein kinase that regulates the growth, integrity and polarity of mammalian cells. Recent studies have reported the prognostic value of decreased LKB1 expression in different tumors. However, the results of these studies remain controversial. Therefore, this meta-analysis was performed to more accurately estimate the role of decreased LKB1 in the prognostication of human solid tumors.

Methods

A systematic literature search in the electronic databases PubMed, Embase, Web of Science and CNKI (updated to October 15, 2015) was performed to identify eligible studies. The overall survival (OS), relapse-free survival (RFS), disease-free survival (DFS) and clinicopathological features data were collected from these studies. The hazard ratios (HRs), odds ratios (ORs) and 95% confidence intervals (CIs) were calculated and pooled with a random-effects models using Stata12.0 software.

Results

A total of 14 studies covering 1915 patients with solid tumors were included in this meta-analysis. Decreased LKB1 was associated with poorer OS in both the univariate (HR: 1.86, 95%CI: 1.42–2.42, P<0.001) and multivariate (HR: 1.55, 95%CI: 1.09–2.21, P = 0.015) analyses. A subgroup analysis revealed that the associations between decreased LKB1 and poor OS were significant within the Asian region (HR 2.18, 95%CI: 1.66–2.86, P<0.001) and obvious for lung cancer (HR: 2.16, 95%CI: 1.47–3.18, P<0.001). However, the articles that involved analyses of both RFS and DFS numbered only 3, and no statistically significant correlations of decreased LKB1 with RFS or DFS were observed in this study. Additionally, the pooled odds ratios (ORs) indicated that decreased LKB1 was associated with larger tumor size (OR: 1.60, 95%CI: 1.09–2.36, P = 0.017), lymph node metastasis (OR: 2.41, 95%CI: 1.53–3.78, P<0.001) and a higher TNM stage (OR: 3.35, 95%CI: 2.20–5.09, P<0.001).

Conclusion

These results suggest that decreased LKB1 expression in patients with solid tumors might be related to poor prognosis and serve as a potential predictive marker of poor clinicopathological prognostic factors. Additional studies are required to verify the clinical utility of decreased LKB1 in solid tumors.

[Metastasis of pancreatic tumors]

With a 5-year survival rate that has remained stagnant at 6 % for decades, pancreatic ductal adenocarcinoma (PDAC) is still one of the most fatal malignancies. Despite intensive research, currently available therapy options are less than adequate. As more than half of the patients already show distant metastases at the time of diagnosis, metastatic disease should be a primary focus in the development of new therapeutic strategies. New findings from basic research provide various interesting approaches: molecular profiling of the primary tumor seems to be a possible method to gain knowledge about the prognosis, metastatic potential and therapy response of each individual case of PDAC. Certain subpopulations of cancer stem cells also seem to be of importance in metastasis of PDAC and could become potential therapeutic targets in the future. Interactions between tumor cells and their microenvironment are another crucial factor in the metastasis of pancreatic cancer and present various new starting points for potential therapies. As the number of cell types and signaling pathways that are found to play a role in PDAC metastasis continue to grow, the next big challenge will be to translate these findings into viable clinical applications.

Process of hepatic metastasis from pancreatic cancer: biology with clinical significance

PURPOSE

Pancreatic cancer shows a remarkable preference for the liver to establish secondary tumors. Selective metastasis to the liver is attributed to the development of potential microenvironment for the survival of pancreatic cancer cells. This review aims to provide a full understanding of the hepatic metastatic process from circulating pancreatic cancer cells to their settlement in the liver, serving as a basic theory for efficient prediction and treatment of metastatic diseases.

METHODS

A systematic search of relevant original articles and reviews was performed on PubMed, EMBASE and Cochrane Library for the purpose of this review.

RESULTS

Three interrelated phases are delineated as the contributions of the interaction between pancreatic cancer cells and the liver to hepatic metastasis process. Chemotaxis of disseminated pancreatic cancer cells and simultaneous defensive formation of platelets or neutrophils facilitate specific metastasis toward the liver. Remodeling of extracellular matrix and stromal cells in hepatic lobules and angiogenesis induced by proangiogenic factors support the survival and growth of clinical micrometastasis colonizing the liver. The bimodal role of the immune system or prevalence of cancer cells over the immune system makes metastatic progression successfully proceed from micrometastasis to macrometastasis.

CONCLUSIONS

Pancreatic cancer is an appropriate research object of cancer metastasis representing more than a straight cascade. If any of the successive or simultaneous phases, especially tumor-induced immunosuppression, is totally disrupted, hepatic metastasis will be temporarily under control or even cancelled forever. To shrink cancers on multiple fronts and prolong survival for patients, novel oral or intravenous anti-cancer agents covering one or different phases of metastatic pancreatic cancer are expected to be integrated into innovative strategies on the premise of safety and efficacious biostability.