PGK1 as predictor of CXCR4 expression, bone marrow metastases and survival in neuroblastoma

Perfusion-Based Bioreactor Culture and Isothermal Microcalorimetry for Preclinical Drug Testing with the Carbonic Anhydrase Inhibitor SLC-0111 in Patient-Derived Neuroblastoma

Neuroblastoma is a rare disease. Rare are also the possibilities to test new therapeutic options for neuroblastoma in clinical trials. Despite the constant need to improve therapy and outcomes for patients with advanced neuroblastoma, clinical trials currently only allow for testing few substances in even fewer patients. This increases the need to improve and advance preclinical models for neuroblastoma to preselect favorable candidates for novel therapeutics. Here we propose the use of a new patient-derived 3D slice-culture perfusion-based 3D model in combination with rapid treatment evaluation using isothermal microcalorimetry exemplified with treatment with the novel carbonic anhydrase IX and XII (CAIX/CAXII) inhibitor SLC-0111. Patient samples showed a CAIX expression of 18% and a CAXII expression of 30%. Corresponding with their respective CAIX expression patterns, the viability of SH-EP cells was significantly reduced upon treatment with SLC-0111, while LAN1 cells were not affected. The inhibitory effect on SH-SY5Y cells was dependent on the induction of CAIX expression under hypoxia. These findings corresponded to thermogenesis of the cells. Patient-derived organotypic slice cultures were treated with SLC-0111, which was highly effective despite heterogeneity of CAIX/CAXII expression. Thermogenesis, in congruence with the findings of the histological observations, was significantly reduced in SLC-0111-treated samples. In order to extend the evaluation time, we established a perfusion-based approach for neuroblastoma tissue in a 3D perfusion-based bioreactor system. Using this system, excellent tissue quality with intact tumor cells and stromal structure in neuroblastoma tumors can be maintained for 7 days. The system was successfully used for consecutive drug response monitoring with isothermal microcalorimetry. The described approach for drug testing, relying on an advanced 3D culture system combined with a rapid and highly sensitive metabolic assessment, can facilitate development of personalized treatment strategies for neuroblastoma.

PGK1 contributes to tumorigenesis and sorafenib resistance of renal clear cell carcinoma via activating CXCR4/ERK signaling pathway and accelerating glycolysis

Phosphoglycerate kinase 1 (PGK1) has complicated and multiple functions in cancer occurrence, tumor progression and drug resistance. Sorafenib is the first-line treatment targeted drug for patients with kidney renal clear cell carcinoma (KIRC) as a tyrosine kinase inhibitor, but sorafenib resistance is extremely common to retard therapy efficiency. So far, it is unclear whether and how PGK1 is involved in the pathogenesis and sorafenib resistance of KIRC. Herein, the molecular mechanisms of PGK1-mediated KIRC progression and sorafenib resistance have been explored by comprehensively integrative studies using biochemical approaches, mass spectrometry (MS) identification, microarray assay, nude mouse xenograft model and bioinformatics analysis. We have confirmed PGK1 is specifically upregulated in KIRC based on the transcriptome data generated by our own gene chip experiment, proteomics identification and the bioinformatics analysis for five online transcriptome datasets, and PGK1 upregulation in tumor tissues and serum is indicative with poor prognosis of KIRC patients. In the KIRC tissues, a high expression of PGK1 is often accompanied with an increase of glycolysis-related enzymes and CXCR4. PGK1 exhibits pro-tumorigenic properties in vitro and in a xenograft tumor model by accelerating glycolysis and inducing CXCR4-mediated phosphorylation of AKT and ERK. Moreover, PGK1 promotes sorafenib resistance via increasing CXCR4-mediated ERK phosphorylation. In conclusion, PGK1-invovled metabolic reprogramming and activation of CXCR4/ERK signaling pathway contributes to tumor growth and sorafenib resistance of KIRC.

PGK1 : An Essential Player in Modulating Tumor Metabolism

Phosphoglycerate kinase 1 (PGK1) is the first enzyme in glycolysis to generate a molecule of ATP in the conversion of 1,3-bisphosphoglycerate (1,3-BPG) to 3-phosphoglycerate (3-PG). In addition to the role of glycolysis, PGK-1 acts as a polymerase alpha cofactor protein, with effects on the tricarboxylic acid cycle, DNA replication and repair. Posttranslational modifications such as methylation, phosphorylation, and acetylation have been seen to activate PGK1 in cancer. High levels of intracellular PGK1 are associated with tumorigenesis and progression, and chemoradiotherapy resistance. However, high levels of extracellular PGK1 suppress angiogenesis and subsequently counteract cancer malignancy. Here we have summarized the current knowledge on the mechanisms and effects of PGK1 in various tumor types and evaluated its potential prognostic and therapeutic value in cancer. The data summarized here aims at providing molecular information and new ideas of employing natural products to combat cancer associated with PGK1.

Metabolic protein phosphoglycerate kinase 1 confers lung cancer migration by directly binding HIV Tat specific factor 1

Phosphoglycerate kinase (PGK) is involved in glycolytic and various metabolic events. Dysfunction of PGK may induce metabolic reprogramming and the Warburg effect. In this study, we demonstrated that PGK1, but not PGK2, may play a key role in tumorigenesis and is associated with metastasis. We observed an inverse correlation between PGK1 and the survival rate in several clinical cohorts through bioinformatics statistical and immunohistochemical staining analyses. Surprisingly, we found that PGK1 was significantly increased in adenocarcinoma compared with other subtypes. Thus, we established a PGK1-based proteomics dataset by a pull-down assay. We further investigated HIV-1 Tat Specific Factor 1 (HTATSF1), a potential binding partner, through protein–protein interactions. Then, we confirmed that PGK1 indeed bound to HTATSF1 by two-way immunoprecipitation experiments. In addition, we generated several mutant clones of PGK1 through site-directed mutagenesis, including mutagenesis of the N-terminal region, the enzyme catalytic domain, and the C-terminal region. We observed that even though the phosphoglycerate kinase activity had been inhibited, the migration ability induced by PGK1 was maintained. Moreover, our immunofluorescence staining also indicated the translocation of PGK1 from the cytoplasm to the nucleus and its colocalization with HTATSF1. From the results presented in this study, we propose a novel model in which the PGK1 binds to HTATSF1 and exerts functional control of cancer metastasis. In addition, we also showed a nonenzymatic function of PGK1.

Perspective on Similarities and Possible Overlaps of Congenital Disease Formation-Exemplified on a Case of Congenital Diaphragmatic Hernia and Neuroblastoma in a Neonate

The coincidence of two rare diseases such as congenital diaphragmatic hernia (CDH) and neuroblastoma is exceptional. With an incidence of around 2–3:10,000 and 1:8000 for either disease occurring on its own, the chance of simultaneous presentation of both pathologies at birth is extremely low. Unfortunately, the underlying processes leading to congenital malformation and neonatal tumors are not yet thoroughly understood. There are several hypotheses revolving around the formation of CDH and neuroblastoma. The aim of our study was to put the respective hypotheses of disease formation as well as known factors in this process into perspective regarding their similarities and possible overlaps of congenital disease formation. We present the joint occurrence of these two rare diseases based on a patient presentation and immunochemical prognostic marker evaluation. The aim of this manuscript is to elucidate possible similarities in the pathogeneses of both disease entities. Discussed are the role of toxins, cell differentiation, the influence of retinoic acid and NMYC as well as of hypoxia. The detailed discussion reveals that some of the proposed pathophysiological mechanisms of both malformations have common aspects. Especially disturbances of the retinoic acid pathway and NMYC expression can influence and disrupt cell differentiation in either disease. Due to the rarity of both diseases, interdisciplinary efforts and multi-center studies are needed to investigate the reasons for congenital malformations and their interlinkage with neonatal tumor disease.

AQP1 Is Up-Regulated by Hypoxia and Leads to Increased Cell Water Permeability, Motility, and Migration in Neuroblastoma

The water channel aquaporin 1 (AQP1) has been implicated in tumor progression and metastasis. It is hypothesized that AQP1 expression can facilitate the transmembrane water transport leading to changes in cell structure that promote migration. Its impact in neuroblastoma has not been addressed so far. The objectives of this study have been to determine whether AQP1 expression in neuroblastoma is dependent on hypoxia, to demonstrate whether AQP1 is functionally relevant for migration, and to further define AQP1-dependent properties of the migrating cells. This was determined by investigating the reaction of neuroblastoma cell lines, particularly SH-SY5Y, Kelly, SH-EP Tet-21/N and SK-N-BE(2)-M17 to hypoxia, quantitating the AQP1-related water permeability by stopped-flow spectroscopy, and studying the migration-related properties of the cells in a modified transwell assay. We find that AQP1 expression in neuroblastoma cells is up-regulated by hypoxic conditions, and that increased AQP1 expression enabled the cells to form a phenotype which is associated with migratory properties and increased cell agility. This suggests that the hypoxic tumor microenvironment is the trigger for some tumor cells to transition to a migratory phenotype. We demonstrate that migrating tumor cell express elevated AQP1 levels and a hypoxic biochemical phenotype. Our experiments strongly suggest that elevated AQP1 might be a key driver in transitioning stable tumor cells to migrating tumor cells in a hypoxic microenvironment.

Hypoxia and its therapeutic possibilities in paediatric cancers

In tumours, hypoxia-a condition in which the demand for oxygen is higher than its availability-is well known to be associated with reduced sensitivity to radiotherapy and chemotherapy, and with immunosuppression. The consequences of hypoxia on tumour biology and patient outcomes have therefore led to the investigation of strategies that can alleviate hypoxia in cancer cells, with the aim of sensitising cells to treatments. An alternative therapeutic approach involves the design of prodrugs that are activated by hypoxic cells. Increasing evidence indicates that hypoxia is not just clinically significant in adult cancers but also in paediatric cancers. We evaluate relevant methods to assess the levels and extent of hypoxia in childhood cancers, including novel imaging strategies such as oxygen-enhanced magnetic resonance imaging (MRI). Preclinical and clinical evidence largely supports the use of hypoxia-targeting drugs in children, and we describe the critical need to identify robust predictive biomarkers for the use of such drugs in future paediatric clinical trials. Ultimately, a more personalised approach to treatment that includes targeting hypoxic tumour cells might improve outcomes in subgroups of paediatric cancer patients.

AQP1-Driven Migration Is Independent of Other Known Adverse Factors but Requires a Hypoxic Undifferentiated Cell Profile in Neuroblastoma

Neuroblastoma is a biologically very heterogeneous tumor with its clinical manifestation ranging from spontaneous regression to highly aggressive metastatic disease. Several adverse factors have been linked to oncogenesis, tumor progression and metastases of neuroblastoma including NMYC amplification, the neural adhesion molecule NCAM, as well as CXCR4 as a promoter of metastases. In this study, we investigate to what extent the expression of AQP1 in neuroblastoma correlates with changing cellular factors such as the hypoxic status, differentiation, expression of known adverse factors such as NMYC and NCAM, and CXCR4-related metastatic spread. Our results show that while AQP1 expression leads to an increased migratory behavior of neuroblastoma cells under hypoxic conditions, we find that hypoxia is associated with a reduction of NMYC in the same cells. A similar effect can be observed when using the tetracycline driven mechanism of SH-EP/Tet cells. When NMYC is not expressed, the expression of AQP1 is increased together with an increased expression of HIF-1α and HIF-2α. We furthermore show that when growing cells in different cell densities, they express AQP1, HIF-1α, HIF-2α, NMYC and NCAM to different degrees. AQP1 expression correlates with a hypoxic profile of these cells with increased HIF-1α and HIF-2α expression, as well as with NMYC and NCAM expression in two out of three neuroblastoma cell lines. When investigating cell properties of the cells that actually migrate, we find that the increased APQ1 expression in the migrated cells correlates with an increased NMYC and NCAM expression again in two out of three cell lines. Expression of the tumor cell homing marker CXCR4 varies between different tumor areas and between cell lines. While some migrated tumor cells highly express CXCR4, cells of other origin do not. In the initial phase of migration, we determined a dominant role of AQP1 expression of migrating cells in the scratch assay.

Co-culture With Human Breast Adipocytes Differentially Regulates Protein Abundance in Breast Cancer Cells

BACKGROUND/AIM

Recent research highlights the role of cancer-associated adipocytes (CAA) in promoting breast cancer cell migration, invasion and resistance to therapy. This study aimed at identifying cellular proteins differentially regulated in breast cancer cells co-cultured with CAA.

MATERIALS AND METHODS

Adipocytes isolated from human breast adipose tissue were co-cultured with hormone receptor-positive (MCF-7) or -negative (MDA-MB-231) breast cancer cells using a transwell co-culture system. Proteomes of co-cultured and control breast cancer cells were compared quantitatively using iTRAQ labelling and tandem mass spectrometry, and the results were validated by western blotting.

RESULTS

A total of 1,126 and 1,218 proteins were identified in MCF-7 and MDA-MB-231 cells, respectively. Among these, 85 (MCF-7) and 63 (MDA-MB-231) had an average fold change >1.5 following co-culture. Pathway analysis revealed that CAA-induced enrichment of proteins involved in metabolism, the ubiquitin proteasome, and purine synthesis.

CONCLUSION

This study provides a proteomic platform for investigating the paracrine role of CAA in promoting breast cancer cell metastasis and resistance to therapy.

Comprehensive Characterization of Circular RNAs in Neuroblastoma Cell Lines

Neuroblastoma (NB) is a rare type of cancer but frequently occurred in children. However, it is still unclear whether circular RNAs (circRNAs) play key roles in NB tumorigenesis or progression. In this study, we identified 39,022 circRNAs across the 39 neuroblastoma and 2 normal cell lines. With the gene and circRNA expression data, we classified the NB cell lines, identified and characterized the functional circRNAs in the 3 NB classes. Specifically, 29 circRNAs were found to be dysregulated in the NB classes. Notably, 7 circRNAs located within MYCN-amplified regions were upregulated in cell lines with the high activities of MYC targets and MYCN amplification, and were highly correlated with expression of their parental gene, NBAS. Subsequently, we constructed ceRNA networks for the functional circRNAs. Specifically, hsa_circ_0005379 was identified as a critical regulator in the ceRNA networks because of targeting 13 genes, which formed a complex competing endogenous RNA (ceRNA) network. Moreover, hsa_circ_0002343, which was connected with few genes, might regulate the PI3K/Akt/mTOR signaling via RAC1. Furthermore, 3 genes, including NOTCH2, SERPINH1, and LAMC1, involved in epithelial mesenchymal transition (EMT) were observed to connect with hsa_circ_0001361, suggesting that this circRNA was closely associated with EMT. Consequently, 7 genes, such as DAD1, PPIA, NOTCH2, PGK1, BUB1, EIF2S1, and TCF7L2, were found to be closely associated with both event-free survival (EFS) and overall survival (OS). In conclusion, the present study identified functional circRNAs and predicted their functionality in neuroblastoma cell lines, which not only improved the understanding of circRNAs in neuroblastoma, but also provided the evidences for the related researchers.

PGK1-mediated cancer progression and drug resistance

Phosphoglycerate kinase 1 (PGK1) is an essential enzyme in the aerobic glycolysis pathway. PGK1 catalyzes the reversible transfer of a phosphate group from 1,3-bisphosphoglycerate to ADP and produces 3-phosphoglycerate and ATP. In addition to cell metabolism regulation, PGK1 is involved in multiple biological activities, including angiogenesis, autophagy and DNA repair. Because of its multi-faceted functions, PGK1's involvement in cancer development is complicated. High intracellular expression of PGK1 leads to tumor cell proliferation. However, high extracellular expression of PGK1 suppresses cancer malignancy through a suppression of angiogenesis. PGK1 is also associated with chemoradiotherapy resistance and poor prognosis of cancer patients. In this manuscript, we summarize the influence of PGK1 and its post-translational modifications on cancer initiation and progression. PGK1-mediated drug resistance and potential small molecule inhibitors targeting PGK1 are discussed for their future clinical applications.

PGK1 Drives Hepatocellular Carcinoma Metastasis by Enhancing Metabolic Process

During the proliferation and metastasis, the tumor cells prefer glycolysis (Warburg effect), but its exact mechanism remains largely unknown. In this study, we demonstrated that phosphoglycerate kinase 1 (PGK1) is an important enzyme in the pathway of metabolic glycolysis. We observed a significant overexpression of PGK1 in hepatocellular carcinoma tissues, and a correlation between PGK1 expression and poor survival of hepatocellular carcinoma patients. Also, the depletion of PGK1 dramatically reduced cancer cell proliferation and metastasis, indicating an oncogenic role of PGK1 in liver cancer progression. Further experiments showed that PGK1 played an important role in MYC-induced metabolic reprogramming, which led to an enhanced Warburg effect. Our results revealed a new effect of PGK1, which can provide a new treatment strategy for hepatocellular carcinoma, as PGK1 is used to indicate the prognosis of hepatocellular carcinoma (HCC).

Curcumin inhibits prostate cancer by targeting PGK1 in the FOXD3/miR-143 axis

PURPOSE

Curcumin is a potent antitumor agent. The objective of this study was to explore the interaction between curcumin and PGK1, an oncogene in the FOXD3/miR-143 axis, in prostate cancer therapy.

METHODS

MiRNA microarray analysis was used to identify miRNAs upregulated by curcumin treatment. MiR-143 was dramatically upregulated by curcumin. Cells were treated with antimiR-143 in combination to curcumin, followed by examining cell viability and migration. Bioinformatics analysis was used to investigate target genes of miR-143. The interaction between miR-143 and PGK1 was evaluated with dual-luciferase assay. Since FOXD3 is important in the regulation of miR-143, we explored whether curcumin regulated FOXD3 expression. FOXD3 was also ectopically overexpressed to investigate its effects on curcumin's regulation of miR-143.

RESULTS

Curcumin treatment significantly upregulated miR-143 and decreased prostate cancer cell proliferation and migration. Those effects were attenuated by anti-miR-143 transfection. Both miR-143 overexpression and curcumin treatment inhibited PGK1 expression and ectopic expression of PGK1 antagonized curcumin's antitumor effects. FOXD3 was upregulated by miR-143. Ectopic expression of FOXD3 synergized with curcumin in upregulating miR-143 expression.

CONCLUSION

Curcumin inhibits prostate cancer by upregulating miR-143. PGK1 is downregulated by miR-143, and FOXD3 upregulation is essential for the antitumor effect of curcumin.

MgF3- and AlF4- transition state analogue complexes of yeast phosphoglycerate kinase

The phospho-transfer mechanism of yeast phosphoglycerate kinase (PGK) has been probed through formation of trifluoromagnesate (MgF₃^-) and tetrafluoroaluminate (AlF₄^-) transition state analogue complexes and analyzed using ¹⁹F, ¹H waterLOGSY and ¹H chemical shift perturbation NMR spectroscopy. We observed the first ¹⁹F NMR spectroscopic evidence for the formation of metal fluoride transition state analogues of yeast PGK and also observed significant changes to proton chemical shifts of PGK in the presence, but not in the absence, of fluoride upon titration of ligands, providing indirect evidence of the formation of a closed ternary transition state. WaterLOGSY NMR spectroscopy experiments using an uncompetitive model were used in an attempt to measure ligand binding affinities within the transition state analogue complexes.

Influence of hypoxia-dependent factors on the progression of neuroblastoma

PURPOSE

Several oxygen-dependent factors, e.g., CAIX (carbonic anhydrase IX) or phosphoglycerate kinase 1 (PGK1) interacting with the CXCR4/SDF1 axis (chemokine receptor 4/stromal cell derived factor 1) have been shown to be involved in processes of tumour pathology including tumourigenicity, tumour cell dissemination and poor survival in several solid tumour entities. The aim of the current study was to evaluate the influence of the hypoxia-inducible factors CAIX and PGK1 on progression of neuroblastoma and to evaluate the clinical relevance of possible therapeutic approaches.

METHODS

Expression of hypoxia-dependent factors PGK1 and CAIX was examined in neuroblastoma specimen, was correlated with clinical parameters, and was studied in neuroblastoma cells. The impact of these hypoxic factors was evaluated by proliferation assays under targeted therapy.

RESULTS

Expression of hypoxia-dependent factors was found in 50 % of neuroblastoma specimen. In neuroblastoma cells, CAIX and PGK1 expression is up regulated under hypoxia and correlates with response to targeted anti-proliferative treatment. The negative impact on survival, although significant for both CAIX and PGk1, appears to be stronger for CAIX.

CONCLUSIONS

Our results show that the hypoxic factors in the tumour`s microenvironment further the progression of tumour disease. This strengthens the perspectives for additive novel therapeutic approaches targeting hypoxia-dependent factors in this childhood disease.

Characteristics of testis-specific phosphoglycerate kinase 2 and its association with human sperm quality

STUDY QUESTION

Is there an association between the expression of phosphoglycerate kinase (PGK) 2 in spermatozoa and sperm quality in both elderly men and young asthenozoospermia patients?

SUMMARY ANSWER

Spermatozoa from elderly men and young asthenozoospermia patients show decreased expression of PGK2, which has a close positive relationship with sperm quality.

WHAT IS KNOWN ALREADY

PGK1 and PGK2 are involved in spermatogenesis and thought to be related to sperm motility. However, limited information is known about their temporal-spatial expression in human spermatogenesis and their relationship with sperm quality.

STUDY DESIGN, SIZE, DURATION

This was a case-control study including 30 healthy young males (aged 28-31 years), 30 elderly men (aged 68-70 years), and 30 asthenozoospermic patients (aged 25-40 years, progressive motility <32%) who donated semen samples. Furthermore, young testes samples were obtained from five fathers (27-33 years old) who had died in car accidents, while aged testes samples were obtained from five elderly fathers (78-82 years old) who were prostate cancer patients.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Semen samples from young adults, elderly men and asthenozoospermic patients were prepared, and their parameters were assessed by Computer-Aided Sperm Analysis (CASA). Sperm proteins were extracted for western blot analysis. Immunohistochemistry was used to characterize the cellular localization of PGK1 and PGK2 in testes samples. Sperm immunofluorescence quantification experiments identified the differential expression of PGK1 and PGK2 in sperm from young adults, elderly men and asthenozoospermic patients. Antibodies against PGK1 and PGK2 were used to test their influence on sperm motility and penetration into viscous media. A modified Kremer test using methyl cellulose was adopted to assess sperm function via penetration into viscous media.

MAIN RESULTS AND THE ROLE OF CHANCE

Cellular localization analysis showed that PGK1 was mainly expressed in spermatogonia whereas PGK2 was mainly expressed in round spermatids. Expression levels of both PGKs were significantly decreased in the testis with ageing (P < 0.05). Western blot and immunofluorescence quantification showed markedly lower expression of PGK2 (P < 0.05) in sperm from elderly men or asthenozoospermic patients compared sperm from with healthy young men. Sperm functional analysis validated the close relationship between expression of PGK2 and sperm motility (staining percentage, r = 0.60, P < 0.05; intensity, r = 0.59, P < 0.05). Use of an anti-PGK2 antibody on sperm significantly decreased their ability to penetrate into a cervical mucus substitute (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

Before any clinical applications using PGK2 to assess sperm quality can be developed, more cases should be used to evaluate this approach.

WIDER IMPLICATIONS OF THE FINDINGS

The study provides new insights into the role of PGKs in male reproduction. The results also indicate that PGK2 is a promising molecular candidate for the assessment of sperm quality and the screening of male contraceptive targets.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the National Natural Science Foundation of China (no. 81300533, 81370013 and 81000277) and Shandong Provincial Natural Science Foundation, China (ZR2013HQ002). The authors declare no competing financial interests.

Down-Regulated Phosphoglycerate Kinase 1 Expression Is Associated With Poor Prognosis in Patients With Gallbladder Cancer

To evaluate prognostic significance of phosphoglycerate kinase 1 (PGK1) protein expression in patients with gallbladder cancer (GBC).Ninety-five patients who underwent surgical resection for GBC between January 2004 and December 2010 were enrolled. Overall survival (OS) and disease-free survival (DFS) were evaluated over a 10-year follow-up. PGK1 expression was assessed by tissue microarray and immunohistochemistry. Prognostic significance was analyzed using multivariate Cox regression.PGK1 was highly expressed in all gallbladder mucosa. Decreased PGK1 expression was detected in 54.7% (52/95) of patients with GBC. It was significantly down-regulated in GBC samples compared with that in gallbladder mucosa (P < 0.0001), and was associated with multiple clinicopathological factors. Multivariate survival analysis showed that low PGK1 expression was associated with shorter OS (median 12.8 vs 45.4 months; hazard ratio [HR] = 3.077; 95% confidence interval [CI], 1.373-6.897; P = 0.006) and DFS (median 8.3 vs 37.9 months; HR = 2.988; 95% CI, 1.315-6.790; P = 0.009), indicating that PGK1 expression was an independent prognostic factor in patients with GBC.Low PGK1 expression was associated with progression in patients with GBC. PGK1 expression could be a useful prognostic biomarker for GBC.

Evaluation of bone marrow as a metastatic site of human neuroblastoma

Arising from neural crest cells, neuroblastoma (NB) is the most common extracranial pediatric solid tumor. The clinical presentation of NB is heterogeneous, ranging from patients with asymptomatic tumor masses, who require minimal treatment, to patients with metastatic disease who are treated with multimodal therapies. Clinical outcome is also variable, with overall survival ranging from 98% to 100% in infants with stage 1 NB, to less than 30% in patients with stage 4 MYCN-amplified NB. More than 50% of patients show metastasis at diagnosis, with the involvement of different vascularized tissues, including the bone marrow (BM). In this paper, we focus on BM infiltration by NB cells, which is considered an adverse prognostic factor. In particular, we discuss the role of different biological factors that may favor the dissemination of NB cells in the BM, such as chromosomic abnormalities, gene amplification, transcription factors, cell-surface receptors, products of oncogenes, and, more importantly, cytokines and chemokines. In addition, we analyze different techniques to evaluate BM infiltration by malignant cells (i.e., flow cytometry, immunocytochemistry, and quantitative reverse transcriptase polymerase chain reaction). Finally, we review recent data regarding phenotypic and genetic characterization of BM-infiltrating malignant cells and characterization of the BM microenvironment in NB patients compared to healthy subjects.