Presence of elevated levels of platelet-derived growth factor (PDGF) in lung adenocarcinoma pleural effusions

Accelerated Wound Healing and Keratinocyte Proliferation through PI3K/Akt/pS6 and VEGFR2 Signaling by Topical Use of Pleural Fluid

Impaired wound healing is an ongoing issue that cancer patients undergoing chemotherapy or radiotherapy face. Our previous study regarding lung-cancer-associated pleural fluid (LCPF) demonstrated its propensity to promote endothelial proliferation, migration, and angiogenesis, which are crucial features during cutaneous wound healing. Therefore, the current study aimed to investigate the effect of pleural fluid on cutaneous wound closure in vitro and in vivo using HaCaT keratinocytes and a full-thickness skin wound model, respectively. Both heart-failure-associated pleural fluid (HFPF) and LCPF were sequentially centrifuged and filtered to obtain a cell-free status. Treatment with HFPF and LCPF homogeneously induced HaCaT proliferation with cell cycle progression, migration, and MMP2 upregulation. Western blotting revealed increased PI3K/Akt phosphorylation and VEGFR2/VEGFA expression in HaCaT cells. When treated with the PI3K inhibitor, LCPF-induced keratinocyte proliferation was attenuated with decreased pS6 levels. By applying the VEGFR2 inhibitor, LCPF-induced keratinocyte proliferation was ameliorated by pS6 and MMP2 downregulation. The effect of LCPF-induced cell junction rearrangement was disrupted by co-treatment with a VEGFR2 inhibitor. Compared with a 0.9% saline dressing, LCPF significantly accelerated wound closure and re-epithelization when used as a dressing material in a full-thickness wound model. Histological analysis revealed increased neo-epidermis thickness and dermis collagen synthesis in the LCPF-treated group. Furthermore, LCPF treatment activated basal keratinocytes at the wound edge with the upregulation of Ki-67, VEGFA, and MMP2. Our preliminaries provided the benefit of wet dressing with pleural fluid to improve cutaneous wound closure through enhanced re-epithelization and disclosed future autologous application in cancer wound treatment.

Plasma-Derived Extracellular Vesicles Convey Protein Signatures that Reflect Pathophysiology in Lung and Pancreatic Adenocarcinomas

Using a combination of mass-spectrometry and aptamer array-based proteomics, we characterized the protein features of circulating extracellular vesicles (EVs) in the context of lung (LUAD) and pancreatic ductal (PDAC) adenocarcinomas. We profiled EVs isolated from conditioned media of LUAD and PDAC cell lines to identify EV-associated protein cargoes released by these cancer cell types. Analysis of the resulting data identified LUAD and PDAC specific and pan-adenocarcinoma EV protein signatures. Bioinformatic analyses confirmed enrichment of proteins annotated to vesicle-associated processes and intracellular compartments, as well as representation of cancer hallmark functions and processes. Analysis of upstream regulator networks indicated significant enrichment of TP53, MYC, TGFB1 and KRAS-driven network effectors (p = 1.69 × 10^-77-2.93 × 10^-49) manifest in the adenocarcinoma sEV protein cargoes. We extended these findings by profiling the proteome of EVs isolated from lung (N = 15) and pancreatic ductal (N = 6) adenocarcinoma patient plasmas obtained at time of diagnosis, along with EVs derived from matched healthy controls (N = 21). Exploration of these proteomic data revealed abundant protein features in the plasma EVs with capacity to distinguish LUAD and PDAC cases from controls, including features yielding higher performance in the plasma EV isolates relative to unfractionated plasmas.

Overexpression of Platelet-Derived Growth Factor and Its Receptor Are Correlated with Oral Tumorigenesis and Poor Prognosis in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a cancerous disease with poor prognosis. According to the statistics, the 5-year survival rate has not improved significantly over the past 20 years. The platelet-derived growth factor (PDGF) and its signaling pathway is a key regulator of angiogenesis and tumorigenesis. High level of PDGF and its receptor (PDGFR) have been reported in several types of malignancies. In this study, we investigated the relationship of the molecular expression levels of PDGF and PDGFR with clinicopathological parameters in OSCC. To this end, we measured the mRNA and protein levels of PDGF and PDGFR by real-time quantitative PCR (qRT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA), respectively. We found positive correlations of the mRNA levels of PDGFA, PDGFB, and PDGFRB with lymph node metastasis and poor overall survival (OS). High expression of PDGF, PDGFRA, and PDGFRB were remarkably associated with lymph node metastasis and poor OS, as determined by immunohistochemistry. Preoperative serum levels of PDGF-AA and PDGF-BB had a positive correlation with preoperative platelet count. Elevated serum levels of PDGF-AA. PDGF-BB, and platelet count correlated with lymph node metastasis and an unfavorable outcome. In multivariate Cox regression analysis, PDGFA mRNA, PDGFB mRNA, PDGFRB mRNA, PDGF immunoexpression, PDGFRB immunoexpression, serum PDGF-AA, serum PDGF-BB, and platelet count emerged as significant independent prognostic factors for OS. In vitro, we found that elevated PDGF promotes colony formation, migration, and invasiveness of SAS and OECM-1 cancer cell lines. Our results suggest that the expression level of serum PDGF has the potential to become a useful diagnostic marker for the prognosis of OSCC. In addition, PDGFR should be considered as a potential therapeutic target for OSCC. Furthermore, research should be undertaken to elucidate the role of PDGF and PDGFR regarding the behavior of tumor cells in OSCC.

Pleural mesothelial cells in pleural and lung diseases

During development, the mesoderm maintains a complex relationship with the developing endoderm giving rise to the mature lung. Pleural mesothelial cells (PMCs) derived from the mesoderm play a key role during the development of the lung. The pleural mesothelium differentiates to give rise to the endothelium and smooth muscle cells via epithelial-to-mesenchymal transition (EMT). An aberrant recapitulation of such developmental pathways can play an important role in the pathogenesis of disease processes such as idiopathic pulmonary fibrosis (IPF). The PMC is the central component of the immune responses of the pleura. When exposed to noxious stimuli, it demonstrates innate immune responses such as Toll-like receptor (TLR) recognition of pathogen associated molecular patterns as well as causes the release of several cytokines to activate adaptive immune responses. Development of pleural effusions occurs due to an imbalance in the dynamic interaction between junctional proteins, n-cadherin and β-catenin, and phosphorylation of adherens junctions between PMCs, which is caused in part by vascular endothelial growth factor (VEGF) released by PMCs. PMCs play an important role in defense mechanisms against bacterial and mycobacterial pleural infections, and in pathogenesis of malignant pleural effusion, asbestos related pleural disease and malignant pleural mesothelioma. PMCs also play a key role in the resolution of inflammation, which can occur with or without fibrosis. Fibrosis occurs as a result of disordered fibrin turnover and due to the effects of cytokines such as transforming growth factor-β, platelet-derived growth factor (PDGF), and basic fibroblast growth factor; which are released by PMCs. Recent studies have demonstrated a role for PMCs in the pathogenesis of IPF suggesting their potential as a cellular biomarker of disease activity and as a possible therapeutic target. Pleural-based therapies targeting PMCs for treatment of IPF and other lung diseases need further exploration.

Phase I and pharmacokinetic study of TSU-68, a novel multiple receptor tyrosine kinase inhibitor, by twice daily oral administration between meals in patients with advanced solid tumors

PURPOSE

A single-agent dose-escalating phase I and pharmacokinetic study on TSU-68, a novel multiple receptor tyrosine kinase inhibitor, was performed to determine the safety profile, maximum-tolerated dose for Japanese patients with advanced solid tumors and to define the recommended dose of phase II studies.

METHODS

Study design was a dose escalation method on a three-patient cohort. TSU-68 was given orally twice daily (bid) between meals without interruption; the estimation of dose escalation was based on the toxicity within 4 week administration at each dose level.

RESULTS

Fifteen patients were enrolled into the study. Dose levels studied were 200, 400, 800, and 1,200 mg/m(2) bid. Grade 3 arrhythmia and anemia/thrombocytopenia were observed in 1 patient each at 800 mg/m(2) bid. Three patients discontinued continuous oral administration for 4 weeks at 400 and 800 mg/m(2) bid. At 1,200 mg/m(2) bid, 2 patients discontinued the treatment over 4 weeks for intolerable fatigue and abdominal pain, respectively. No serious drug-related toxicities have been observed. Grade 1-2 toxicity included urinary/feces discoloration, diarrhea, fatigue, anorexia, abdominal/chest pain, and edema. Tumor shrinkage was observed in 1 patient of NSCLC. In the pharmacokinetics, at any dose levels, C(max) and AUC(0-t) after repeated administration of TSU-68 on days 8 and 29 were ~2-fold lower that those after the first administration on day 1; these parameters are similar between days 8 and 28. In addition, no obvious dose-dependent increase in plasma exposure to TSU-68 repeatedly administered was observed over the four dose levels, including the higher dose levels.

CONCLUSIONS

The tolerable dose in this administration schedule for continuing treatment is thought to be 800 mg/m(2) or less bid.

Platelet-derived growth factor (subtype BB) is elevated in patients with colorectal carcinoma

PURPOSE

Platelet-derived growth factor-BB plays a role in the development of vascular and lymphatic vessels in tumors. In this study plasma levels of platelet-derived growth factor-BB were assessed preoperatively in patients with adenomas and colorectal cancer to determine whether platelet-derived growth factor-BB is a useful marker or prognostic indicator.

METHODS

Patients with adenomas and colorectal cancer undergoing resection were assessed. Clinical and pathologic data and preoperative blood samples were collected. Plasma platelet-derived growth factor-BB levels (median, 95 percent confidence interval for median) were determined and the Kruskal-Wallis test and Mann-Whitney U test were used for analysis.

RESULTS

One hundred seventy-nine patients were studied (91 with colorectal cancer, 88 with adenomas). Preoperative colorectal cancer platelet-derived growth factor-BB levels were higher (1,771.1 pg/ml; confidence intervals, 1,429-2,065) than in the benign neoplasm group (1083 pg/ml; confidence intervals, 933-1,192, P < 0.001). In patients with colorectal cancer, a direct relationship was noted between platelet-derived growth factor-BB levels and disease severity. Despite the increase in platelet-derived growth factor-BB noted with increasing stage, the differences between the Stages 1, 2, 3, and 4 groups were not significant.

CONCLUSION

Platelet-derived growth factor-BB levels were greater in patients with colorectal cancer (vs. patients with adenoma) and rose with increasing disease severity. Unfortunately, however, the modest differences between categories do not permit accurate stage determination.

Pathophysiology of the pleura

The pleural mesothelial cell is an essential cell in maintaining the normal homeostasis of the pleural space and it is also a central component of the pathophysiologic processes affecting the pleural space. In this review, we will review the defense mechanisms of the pleural mesothelium and changes in pleural physiology as a result of inflammatory, infectious, and malignant conditions with a focus on cytokine and chemokine networks. We will also review the processes involved in the pathogenesis of pleural fibrosis.

Pleural fibrosis

Pleural fibrosis can result from a variety of inflammatory processes. The response of the pleural mesothelial cell to injury and the ability to maintain its integrity are crucial in determining whether normal healing or pleural fibrosis occurs. The pleural mesothelial cell, various cytokines, and disordered fibrin turnover are involved in the pathogenesis of pleural fibrosis. The roles of these mediators in producing pleural fibrosis are examined. This article reviews the most common clinical conditions associated with the development of pleural fibrosis. Fibrothorax and trapped lung are two unique and uncommon consequences of pleural fibrosis. The management of pleural fibrosis, including fibrothorax and trapped lung, is discussed.

Serum PDGF-AB in pleural mesothelioma

Overexpression of platelet-derived growth factor (PDGF) has been observed in lung and pleural tumors. The aim of this study was to evaluate the diagnostic and prognostic role of serum PDGF in pleural mesothelioma (PM). Four groups of subjects were studied: 93 malignant PM patients, 33 primary non small cell lung cancer patients, 51 subjects exposed to asbestos, defined as high-risk controls, and 24 healthy controls. PDGF-AB mean concentration was higher in PM patients (45.8 ng/ml) than in high-risk controls (33.1 ng/ml) and healthy controls (26.8 ng/ml). Using the cut-off level of 49.8 ng/ml, corresponding to the mean+2SD of PDGF-AB in healthy controls, 43% of PM patients showed positive PDGF-AB levels. Survival was evaluated in 82 PM patients. At the end of the follow-up (median 9.8 months) 80.5% of patients had died. Median survival was 13.1 and 7.9 months for patients with PDGF-AB lower and higher than the cut-off, respectively. Adjusting for age, sex, histology and platelet count, positive PDGF-AB levels were associated with lower survival (OR=1.2, 95%CI: 0.9-1.6), even if not significantly so. In conclusion, serum PDGF may represent a useful additional parameter to prognostic factors already available for PM.

Deletion of tumor suppressor genes in Chinese non-small cell lung cancer

In the present study, we used 22 microsatellite markers flanking to or within 13 known or candidate tumor suppressor genes (TSGs) to detect loss of heterozygosity (LOH) in these chromosomal regions among 41 cases of non-small cell lung cancer, including 28 squamous cell carcinoma (SCC) and 13 adenocarcinoma (ADC). The studied TSGs comprised FHIT, VHL, APC, PRLTS, p16, IFNA, PTEN, p57, ATM, p53, BRCA1, DPC4 and DCC. Our data demonstrated frequent allelic losses of FHIT, p53, IFNA, VHL and p16 in both SCC and ADC. PTEN and ATM showed the least frequency of LOH, while no deletion of BRCA1 was detected in all tumor samples. LOH analysis of PRLTS was extended to 26 cases of ADC, which demonstrated significantly higher frequency of LOH than SCC. Our data indicated a possible correlation between specific TSG(s) and either histological type of lung cancer, and more attention should be paid to the PRLTS gene, which might play an important role in the development of ADC.

Prognostic value of platelet-derived growth factor-A (PDGF-A) in gastric carcinoma

OBJECTIVE

Because our previous study indicated that PDGF-A mRNA expression in biopsy specimens might identify a subgroup of high-risk patients with gastric carcinoma, in this study we analyzed the prognostic value of platelet-derived growth factor-A (PDGF-A) gene expression in gastric carcinoma biopsy specimens.

METHODS

Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to analyze the PDGF-A gene expression in 65 gastric carcinoma endoscopic biopsy specimens. The 65 patients were divided into a PDGF-A-positive group (29 patients) and a PDGF-A-negative group (36 patients).

RESULTS

On the basis of 2-year follow-up data, the PDGF-A-positive group demonstrated a shorter overall survival rate compared with the PDGF-A-negative group (p < 0.0001). A similar correlation was found in 34 advanced-stage patients (p = 0.003) and in 24 advanced-stage patients who underwent a curative resection (p = 0.003). Multivariance analysis indicated that the transcription of PDGF-A gene is a potent prognostic factor that is independent of the traditional pathologic parameters.

CONCLUSIONS

Expression of PDGF-A mRNA in gastric biopsy specimens may be a new preoperative prognostic parameter in gastric carcinoma.

Indolocarbazoles: potent and selective inhibitors of platelet-derived growth factor receptor autophosphorylation

A quantitative assay for measuring the autophosphorylation of platelet-derived growth factor (PDGF) receptors in intact vascular smooth muscle cells has been developed and used to screen for novel tyrosine kinase (TK) inhibitors. Several novel inhibitors of PDGF receptor autophosphorylation have been identified from the indolocarbazole series, including the 3,9 dimethoxy derivative, 3744W (IC50 = 14.5+/-2 nM). Tested against a panel of tyrosine and serine/threonine kinases, 3744W is at least 1,000 fold selective for the PDGF receptor tyrosine kinase and was found to inhibit autophosphorylation of both the alpha and beta isoforms of the PDGF receptor in human smooth muscle cells. PDGF-BB-stimulated DNA synthesis in quiescent cultures of human smooth muscle cells was blocked in a concentration-dependent manner by 3744W, IC50 = 10 nM. Binding studies showed that 3744W did not block the binding of PDGF-BB to cell surface receptors on human airway smooth muscle cells. Furthermore, inhibition of bone marrow stem cell proliferation by 3744W was only observed at concentrations 100-1,000 times greater than those needed to block PDGF-driven DNA synthesis in human smooth muscle cells. 3744W represents a novel, potent and selective inhibitor of PDGF receptor autophosphorylation and a powerful biochemical probe for investigating PDGF-dependent responses in vitro.

Expression of PDGF, IGF-II, bFGF and TGF-beta 1 in pulmonary adenocarcinoma

Effects of the expression of the platelet-derived growth factor (PDGF), insulin-like growth factor-II (IGF-II), basic fibroblast growth factor (bFGF) and transforming growth factor (TGF)-beta 1 were studied individually and in combinations with the clinicopathologic features and prognosis of pulmonary adenocarcinoma using paraffin embedded tissue specimens. Tumor sections from 90 patients with pulmonary adenocarcinoma were stained immunohistochemically for PDGF, IGF-II, bFGF and TGF-beta 1 by the ABC method. The survival rate was worse in patients in whom each of the four growth factors was expressed than in those where growth factors were not expressed. The reduced expression of the four growth factors correlated with less tumor aggressiveness and better prognosis of pulmonary adenocarcinoma.

Usefulness of platelet-derived growth factor as a prognostic factor in pulmonary adenocarcinoma

Platelet-derived growth factor (PDGF) in the resected pulmonary adenocarcinoma tissue of 88 patients was detected immunohistochemically by the avidin-biotin-peroxidase technique to determine whether or not it is a prognostic parameter. The 88 patients were divided into PDGF (-) and PDGF (+) groups according to the stainability of the factor. The PDGF (-) group included 39 patients and the PDGF (+) group 49. The 5-year survival rate was 53% for the PDGF (-) group and 17% for the PDGF (+) group (P < 0.01). These findings indicate that the stainability of PDGF can be a prognostic parameter for pulmonary adenocarcinoma.

In vitro effects of pentoxifylline on smooth muscle cell migration and blood monocyte production of chemotactic activity for smooth muscle cells: potential therapeutic benefit in the adult respiratory distress syndrome

The adult respiratory distress syndrome (ARDS) is a severe lung condition characterized by an acute lung injury leading to a massive intra-alveolar fibrosis with rapid lung failure. ARDS intra-alveolar fibrosis results from the migration of mesenchymal cells (mainly smooth muscle cells [SMC]) into the alveoli through alveolar epithelial basement membrane gaps resulting from the injury. SMC migration is followed by their replication and production of extracellular matrix, which leads to fibrosis. Thus, any pharmacologic agent able to prevent SMC migration should prevent, at least in part, intra-alveolar fibrosis. SMC migration is thought to be due to the presence, in the alveolar spaces, of chemotactic factors for mesenchymal cells, such as fibronectin and platelet-derived growth factor (PDGF). The local presence of these chemotactic factors can be due to plasmatic leakage, platelet degranulation, and mononuclear phagocyte activation. Pentoxifylline is a methylxanthine interacting with the biology of several types of cells, including red blood cells, neutrophils, blood monocytes, and endothelial cells. Pentoxifylline prescription has been suggested in ARDS with respect to its activity on neutrophils, its inhibition of tumor necrosis factor-alpha (TNF) release by mononuclear phagocytes, and its prevention of TNF-induced lung injury. Since pentoxifylline can modulate the migration of several cell types, we hypothesized that it could interfere with mesenchymal cell migration. SMC migratory response was measured in vitro with modified Boyden chemotactic chambers in the presence of PDGF, fibronectin, "platelet extract," and activated blood monocyte supernatants. Pentoxifylline, at therapeutic levels, significantly reduced SMC migration in response to the presence of these chemotactic activities.(ABSTRACT TRUNCATED AT 250 WORDS)