Differential expression of VEGF ligands and receptors in prostate cancer.

BACKGROUND: Prostate cancer disseminates to regional lymph nodes, however the molecular mechanisms responsible for lymph node metastasis are poorly understood. The vascular endothelial growth factor (VEGF) ligand and receptor family have been implicated in the growth and spread of prostate cancer via activation of the blood vasculature and lymphatic systems. The purpose of this study was to comprehensively examine the expression pattern of VEGF ligands and receptors in the glandular epithelium, stroma, lymphatic vasculature and blood vessels in prostate cancer. METHODS: The localization of VEGF-A, VEGF-C, VEGF-D, VEGF receptor (VEGFR)-1, VEGFR-2, and VEGFR-3 was examined in cancerous and adjacent benign prostate tissue from 52 subjects representing various grades of prostate cancer. RESULTS: Except for VEGFR-2, extensive staining was observed for all ligands and receptors in the prostate specimens. In epithelial cells, VEGF-A and VEGFR-1 expression was higher in tumor tissue compared to benign tissue. VEGF-D and VEGFR-3 expression was significantly higher in benign tissue compared to tumor in the stroma and the endothelium of lymphatic and blood vessels. In addition, the frequency of lymphatic vessels, but not blood vessels, was lower in tumor tissue compared with benign tissue. CONCLUSIONS: These results suggest that activation of VEGFR-1 by VEGF-A within the carcinoma, and activation of lymphatic endothelial cell VEGFR-3 by VEGF-D within the adjacent benign stroma may be important signaling mechanisms involved in the progression and subsequent metastatic spread of prostate cancer. Thus inhibition of these pathways may contribute to therapeutic strategies for the management of prostate cancer.

The ADAMTS1 protease gene is required for mammary tumor growth and metastasis.

A disintegrin and metalloprotease with thrombospondin motifs protein 1 (ADAMTS1) is a protease commonly up-regulated in metastatic carcinoma. Its overexpression in cancer cells promotes experimental metastasis, but whether ADAMTS1 is essential for metastatic progression is unknown. To address this question, we investigated mammary cancer progression and spontaneous metastasis in the MMTV-PyMT mouse mammary tumor model in Adamts1 knockout mice. Adamts1(-/-)/PyMT mice displayed significantly reduced mammary tumor and lung metastatic tumor burden and increased survival, compared with their wild-type and heterozygous littermates. Histological examination revealed an increased proportion of tumors with ductal carcinoma in situ and a lower proportion of high-grade invasive tumors in Adamts1(-/-)/PyMT mice, compared with Adamts1(+/+)/PyMT mice. Increased apoptosis with unaltered proliferation and vascular density in the Adamts1(-/-)/PyMT tumors suggested that reduced cell survival accounts for the lower tumor burden in ADAMTS1-deficient mice. Furthermore, Adamts1(-/-) tumor stroma had significantly lesser amounts of proteolytically cleaved versican and increased numbers of CD45(+) leukocytes. Characterization of immune cell gene expression indicated that cytotoxic cell activation was increased in Adamts1(-/-) tumors, compared with Adamts1(+/+) tumors. This finding is supported by significantly elevated IL-12(+) cell numbers in Adamts1(-/-) tumors. Thus, in vivo ADAMTS1 may promote mammary tumor growth and progression to metastasis in the PyMT model and is a potential therapeutic target to prevent metastatic breast cancer.

Integrated mutation, copy number and expression profiling in resectable non-small cell lung cancer.

BACKGROUND: The aim of this study was to identify critical genes involved in non-small cell lung cancer (NSCLC) pathogenesis that may lead to a more complete understanding of this disease and identify novel molecular targets for use in the development of more effective therapies. METHODS: Both transcriptional and genomic profiling were performed on 69 resected NSCLC specimens and results correlated with mutational analyses and clinical data to identify genetic alterations associated with groups of interest. RESULTS: Combined analyses identified specific patterns of genetic alteration associated with adenocarcinoma vs. squamous differentiation; KRAS mutation; TP53 mutation, metastatic potential and disease recurrence and survival. Amplification of 3q was associated with mutations in TP53 in adenocarcinoma. A prognostic signature for disease recurrence, reflecting KRAS pathway activation, was validated in an independent test set. CONCLUSIONS: These results may provide the first steps in identifying new predictive biomarkers and targets for novel therapies, thus improving outcomes for patients with this deadly disease.

Spontaneous acute subdural hematoma complicating arachnoid cyst.

The overwhelming majority of cases of acute subdural hematoma in the forensic setting occur as a result of head trauma. We report a case of sudden unexpected death in a middle-aged woman with a history of arachnoid cyst who had sudden spontaneous onset of severe headache that was rapidly followed by collapse and death. A postmortem multiple-slice computed tomographic scan showed a large acute subdural hematoma associated with hemorrhage into an arachnoid cyst. Subdural hemorrhage is an uncommon but well-described complication of an arachnoid cyst.

Expression of vascular endothelial growth factor receptor-3 by lymphatic endothelial cells is associated with lymph node metastasis in prostate cancer.

PURPOSE: The molecular mechanisms underlying lymph node metastasis are poorly understood, despite the well-established clinical importance of lymph node status in many human cancers. Recently, vascular endothelial growth factor (VEGF)-C and VEGF-D have been implicated in the regulation of tumor lymphangiogenesis and enhancement of lymphatic invasion via activation of VEGF receptor-3. The purpose of this study was to determine the expression pattern of the VEGF-C/VEGF-D/VEGF receptor-3 axis in prostate cancer and its relationship with lymph node metastasis. EXPERIMENTAL DESIGN: The expression pattern of VEGF-C, VEGF-D, and VEGF receptor-3 in localized prostate cancer specimens (n = 37) was determined using immunohistochemistry. RESULTS: Widespread, heterogeneous staining for VEGF-C and VEGF-D was observed in all cancer specimens. Intensity of VEGF-C staining was lower in benign prostate epithelium than in adjacent carcinoma, whereas no difference between benign epithelium and carcinoma was observed for VEGF-D staining. VEGF receptor-3 immunostaining was detected in endothelial cells of lymphatic vessels in 18 of 37 tissue samples. The presence of VEGF receptor-3-positive vessels was associated with lymph node metastasis (P = 0.0002), Gleason grade (P < 0.0001), extracapsular extension (P = 0.0382), and surgical margin status (P = 0.0069). In addition, VEGF receptor-3 staining highlighted lymphatic invasion by VEGF-C-positive/VEGF-D-positive carcinoma cells. CONCLUSIONS: Together, these results suggest that paracrine activation of lymphatic endothelial cell VEGF receptor-3 by VEGF-C and/or VEGF-D may be involved in lymphatic metastasis. Thus the VEGF-C/VEGF-D/VEGF receptor-3 signaling pathway may provide a target for antilymphangiogenic therapy in prostate cancer.

Identification of a by-product of nitric oxide synthase activity in human acute brain injury with in vivo proton magnetic resonance spectroscopy.

BACKGROUND AND PURPOSE: Laboratory studies have been used to identify nitric oxide as a notable mediator in neuronal death after acute brain injury. To our knowledge, this has not previously been confirmed with in vivo study in humans. Our purpose was to seek in vivo evidence for the induction of nitric oxide synthase (NOS) in human acute brain injury by using proton MR spectroscopy. METHODS: In vitro proton MR spectra were obtained in neural extracts from 30 human cadavers, and in vivo spectra were obtained in 20 patients with acute brain injury and in a similar number of control subjects. RESULTS: We identified a unique peak at 3.15 ppm by using in vivo proton MR spectroscopy in eight of 20 patients with acute brain injury but not in 20 healthy volunteers (P <.002). On the basis of in vitro data, we have tentatively assigned this peak to citrulline, a NOS by-product. CONCLUSION: To our knowledge, our findings suggest, for the first time, that excitotoxicity may occur in human acute brain injury. Confirmation with the acquisition of spectra in very early acute cerebral injury would provide a rationale for the use of neuroprotective agents in these conditions, as well as a new noninvasive method for quantification.

Risk factors for sudden unexpected death in epilepsy: a controlled prospective study based on coroners cases.

We performed a controlled prospective study of pathologically verified sudden unexpected death in epilepsy (SUDEP) in a coronial setting, to identify risk factors. We prospectively studied coronial deaths of people with epilepsy in Vic., Australia, during a 21-month period. Fifty SUDEP and 50 subjects with epilepsy who died of other causes (controls) were collected sequentially. Clinical data was obtained shortly after death from questionnaires completed by treating doctors, discussion with family members and coronial files, including police reports of death, autopsy and toxicology reports. Factors assessed were age, sex, duration of epilepsy, type of seizure(s), seizure frequency, symptomatic epilepsy, including post-traumatic epilepsy, presence of structural brain lesion, idiopathic epilepsy, mental retardation, psychiatric illness, including dementia, recent stressful life event, particular antiepileptic drugs (AEDs) and AED polytherapy, compliance with AED treatment, psychotropic drug prescription, alcohol and other substance abuse, place of death and evidence of terminal seizure. The SUDEP group was characterised by younger age and higher proportion found dead in bed and with evidence of terminal seizure compared to controls. The profile of patients at risk for SUDEP are young people with epilepsy. They are most likely to die in sleep and our data support the view that SUDEP is a seizure-related event. This, taken in conjunction with the finding that there was no increased risk associated with a particular AED in monotherapy or multiple AEDs suggests that attempts to better treat patients' epilepsy with AEDs might decrease the risk of SUDEP. Although the literature suggests that SUDEP is more frequent in patients with severe epilepsy, we did not find a correlation with seizure frequency suggesting that other clinical indices may be more important.

Fulminant heart failure due to selenium deficiency cardiomyopathy (Keshan disease).

Selenium deficiency is a rare cause of cardiomyopathy that may be encountered by the forensic pathologist. Selenium deficiency is associated with a cardiomyopathy, myopathy and osteoarthropathy. In Asia and Africa, dietary selenium deficiency is associated with a cardiomyopathy known as Keshan disease and an osteoarthropathy called Kashin-Beck disease. Chronic selenium deficiency may also occur in individuals with malabsorption and long term selenium-deficient parenteral nutrition. Selenium deficiency causes myopathy as a result of the depletion of selenium-associated enzymes which protect cell membranes from damage by free radicals. We present a case of fulminant heart failure in a middle aged woman with a complex medical and surgical history including documented malabsorption and selenium deficiency. Pathological examination of the heart showed features consistent with Keshan disease.

Vascular endothelial growth factor receptor-3 directly interacts with phosphatidylinositol 3-kinase to regulate lymphangiogenesis.

BACKGROUND: Dysfunctional lymphatic vessel formation has been implicated in a number of pathological conditions including cancer metastasis, lymphedema, and impaired wound healing. The vascular endothelial growth factor (VEGF) family is a major regulator of lymphatic endothelial cell (LEC) function and lymphangiogenesis. Indeed, dissemination of malignant cells into the regional lymph nodes, a common occurrence in many cancers, is stimulated by VEGF family members. This effect is generally considered to be mediated via VEGFR-2 and VEGFR-3. However, the role of specific receptors and their downstream signaling pathways is not well understood. METHODS AND RESULTS: Here we delineate the VEGF-C/VEGF receptor (VEGFR)-3 signaling pathway in LECs and show that VEGF-C induces activation of PI3K/Akt and MEK/Erk. Furthermore, activation of PI3K/Akt by VEGF-C/VEGFR-3 resulted in phosphorylation of P70S6K, eNOS, PLCγ1, and Erk1/2. Importantly, a direct interaction between PI3K and VEGFR-3 in LECs was demonstrated both in vitro and in clinical cancer specimens. This interaction was strongly associated with the presence of lymph node metastases in primary small cell carcinoma of the lung in clinical specimens. Blocking PI3K activity abolished VEGF-C-stimulated LEC tube formation and migration. CONCLUSIONS: Our findings demonstrate that specific VEGFR-3 signaling pathways are activated in LECs by VEGF-C. The importance of PI3K in VEGF-C/VEGFR-3-mediated lymphangiogenesis provides a potential therapeutic target for the inhibition of lymphatic metastasis.

Surgical treatment of ruptured metastatic pleomorphic leiomyosarcoma.

A rare case of primary cardiac leiomyosarcoma was diagnosed in a 21-year-old man who presented with a groin mass thought to be a sebaceous cyst. Histopathology revealed a high-grade pleomorphic leiomyosarcoma. Combined positron-emission and computed tomography showed a large metabolically active left atrial mass with multiple metastases. Major debulking resection was undertaken, followed by radiation and chemotherapy. At 13 months postoperatively, limited spread has been detected, and the patient had no limitation in daily life.

Propofol infusion syndrome.

In this article, we present the case of a previously well 31-year-old man who sustained a mild closed-head injury following a motor vehicle incident and was admitted to the intensive care unit of a major teaching hospital. The man was sedated using propofol combined with midazolam and morphine as the main sedating agent. The propofol was started and continued at high dose for 8 days, over which time the patient deteriorated with metabolic acidosis, rhabdomyolysis, renal impairment, and cardiovascular collapse and then died. A forensic autopsy was performed. The only positive autopsy finding was a cardiac perivascular and interstitial infiltrate of mononuclear cells. The clinical and pathological features in the case presented were consistent with propofol infusion syndrome. No other cause for the above features was found and the cause of death was given as death related to propofol infusion syndrome.Propofol infusion syndrome is characterized by metabolic acidosis, rhadbomyolysis, and myocardial failure, sometimes with renal failure and hyperkalemia occurring in the setting of high-dose propofol treatment. The syndrome has become increasingly recognized in recent years. The syndrome is of importance to forensic pathologists who may see cases referred to their practice because of the unexplained deterioration of a patient in the intensive care unit and the association with head-injured patients and the pediatric population. Death associated with propofol infusion has not been described in the forensic literature.

Tumor-induced activation of lymphatic endothelial cells via vascular endothelial growth factor receptor-2 is critical for prostate cancer lymphatic metastasis.

Prostate cancer disseminates initially and primarily to regional lymph nodes. However, the nature of interactions between tumor cells and lymphatic endothelial cells (LEC) is poorly understood. In the current study, we have isolated prostate LECs and developed a series of two-dimensional and three-dimensional in vitro coculture systems and in vivo orthotopic prostate cancer models to investigate the interactions of prostate cancer cells with prostate LECs. In vitro, highly lymph node metastatic prostate cancer cell lines (PC-3 and LNCaP) and their conditioned medium enhanced prostate LEC tube formation and migration, whereas poorly lymph node metastatic prostate cancer cells (DU145) or normal prostate epithelial cells (RWPE-1) or their conditioned medium had no effect. In vivo, the occurrence of lymphatic invasion and lymph node metastasis was observed in PC-3 and LNCaP xenografts but not in DU145 xenografts. Furthermore, vascular endothelial growth factor (VEGF) receptor (VEGFR)-2 is expressed by prostate LECs, and its ligands VEGF-A, VEGF-C, and VEGF-D are up-regulated in highly lymph node metastatic prostate cancer cells. Recombinant VEGF-A and VEGF-C, but not VEGF-C156S, potently promoted prostate LEC tube formation, migration, and proliferation in vitro, indicating that signaling via VEGFR-2 rather than VEGFR-3 is involved in these responses. Consistent with this, blockade of VEGFR-2 significantly reduced tumor-induced activation of LECs. These results show that the interaction of prostate tumor cells with LECs via VEGFR-2 modulates LEC behavior and is related to the ability of tumor cells to form lymph node metastases.