Vascular Endothelial Growth Factor is an Autocrine Growth Factor for Cardiac Myxoma Cells

A 30-Year-Old Woman With Arthralgia, Progressive Dyspnea, and a Syncope Episode

CASE PRESENTATION

A 30-year-old White woman with presumed rheumatoid arthritis accompanied by CT scan evidence of eosinophilic pneumonitis was referred to the ED by her rheumatologist for an investigation of the progression of dyspnea. Approximately 6 months before, the patient reported experiencing diffuse interphalangeal arthralgias (both proximal and distal) that affected the wrists, knees, and feet. These symptoms were accompanied by Modified Medical Research Council scale grade 2 dyspnea. During the initial assessment, the patient exhibited slight pallor and had no indications of inflammatory activity in the joints. Furthermore, the cardiovascular physical examination and the auto-antibody laboratory profile yielded normal results. However, a wrist ultrasound scan revealed evidence of active synovitis; a chest CT scan displayed multifocal bilateral ground-glass opacities and mild thickening of the interlobular septa. These findings suggested the presence of eosinophilic disease or an acute interstitial process related to collagen vascular disease. Consequently, the patient's treatment commenced with a weekly dose of methotrexate (10 mg). Despite the intervention, 2 months later, the patient returned, reporting persistent arthralgia and a worsening of dyspnea, now classified as Modified Medical Research Council scale grade 3. Subsequently, the rheumatologist referred her to the ED for further assessment. During the initial emergency evaluation, the patient experienced a syncope episode accompanied by orthostatic prodromal symptoms that included dizziness, nausea, and malaise.

Cardiac myxomas: causes, presentations, diagnosis, and management

Cardiac myxomas (CM) are one of the most common benign tumors which are typical in adults with a yearly incidence of 0.5-1 case per million individuals. This review article includes discussions based on existing literature on the role of interleukin interactions in the pathophysiology of cardiac myxoma which can lead to embolic complications, aneurysms, and CNS involvement. The objective of this narrative review was to study the variable clinical presentations of cardiac myxoma, its detection and diagnosis involving multiple modalities like genetic and hematological testing, echocardiography, CT, and MRI, of which transoesophageal echocardiogram shows excellent precision with a 90% to 96% accuracy in diagnosing CM. Individuals with the Carney complex are prone to such neoplasia. Cardiac myxomas are challenging to diagnose due to the ambiguity of their differential with thrombi. Myxomas can also be diagnosed by tumor markers like interleukin-6 and endothelial growth factors. The management of CM includes surgical excision like median sternotomy and robotic minimally invasive surgery. The use of robotic surgery in CM increased from 1.8% in 2012 to 15.1% in 2018. Tumor recurrences are uncommon but can occur due to inadequate surgical resection.

Autocrine Regulation of Interleukin-6 via the Activation of STAT3 and Akt in Cardiac Myxoma Cells

Plasma concentrations of a pleiotropic cytokine, interleukin (IL)-6, are increased in patients with cardiac myxoma. We investigated the regulation of IL-6 in cardiac myxoma. Immunohistochemical staining and reverse transcription-polymerase chain reaction (RT-PCR) revealed that IL-6 and its receptors, IL-6 receptor (IL-6R) and gp130, co-existed in the myxoma cells. Myxoma cells were cultured, and an antibody array assay showed that a conditioned medium derived from the cultured myxoma cells contained increased amounts of IL-6. Signal transducer and activator of transcription (STAT) 3 and Akt were constitutively phosphorylated in the myxoma cells. An enzyme-linked immunosorbent assay (ELISA) showed that the myxoma cells spontaneously secreted IL-6 into the culture medium. Real-time PCR revealed that stimulation with IL-6 + soluble IL-6R (sIL6R) significantly increased IL-6 mRNA in the myxoma cells. Pharmacological inhibitors of STAT3 and Akt inhibited the IL-6 + sIL-6R-induced gene expression of IL-6 and the spontaneous secretion of IL-6. In addition, IL-6 + sIL-6R-induced translocation of phosphorylated STAT3 to the nucleus was also blocked by STAT3 inhibitors. This study has demonstrated that IL-6 increases its own production via STAT3 and Akt pathways in cardiac myxoma cells. Autocrine regulation of IL-6 may play an important role in the pathophysiology of patients with cardiac myxoma.

Asymptomatic Pulmonic Valve Mass: A Diagnostic and Therapeutic Dilemma

Cardiac masses are not common but remain important in cardiology practice as they can cause havoc to a patient's life through obstructive and arrhythmogenic symptoms. These lesions mostly include vegetation, thrombi, and tumors. Myxomas are the most common primary cardiac tumor, primarily arising from the left heart chambers. It is exceedingly rare for a myxoma to emerge from the right-sided cardiac valves. The standard treatment is surgical resection, regardless of size, which is not always possible. We report a unique case of a male with multiple co-morbidities who presented with an incidental finding of a pulmonary valve mass suspicious of being a myxoma. The myxomatous mass was asymptomatic with no right ventricular outflow tract obstruction. Echocardiogram can help identify and characterize these lesions, but this may not be easy, especially in the case of atypical location or morphology of the mass. Similarly, in some cases, the patient may not be able to undergo surgical excision. In such cases, there is no consensus or guidelines to help clinicians best manage the patients medically, creating a diagnostic and therapeutic dilemma.

Left Atrial Myxoma Presenting as Persistent Dizziness

Cardiac masses are divided into benign tumors and malignant tumors. The tumor can cause valvular obstruction and embolization phenomenon. To elucidate the etiology of cardiac masses, we rely on the use of echocardiograms in combination with the clinical picture of the patient. We describe an interesting case report of a 71-year-old woman who presented with persistent dizziness for one day. MRI brain showed multiple, small, scattered foci of acute infarction. The patient was treated with aspirin and atorvastatin. Transthoracic echocardiography showed a mass in the left atrium. Afterward, the tumor was removed surgically and histopathology was consistent with atrial myxoma.

Right atrial myxoma as the first manifestation of granulomatosis with polyangiitis, and a possible association with vascular endothelial growth factor (VEGF) and interleukin 6 (IL-6): a case report and review of the literature

Background

Granulomatosis with polyangiitis and myxomas are rare conditions previously described to co-exist. Cardiac masses are often presumed to be myxomas rather than lesions of granulomatosis with polyangiitis.

Case presentation

We present a review of the symptoms for the two diagnoses along with the first verified case.

Conclusions

Two possible risk factors for developing myxomas (VEGF and IL-6) are explored and discussed.

[Extracorporeal cardiopulmonary resuscitation for treatment of out-of-hospital cardiac arrest]

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) affects ca. 75,000 people each year in Germany and is associated with a limited prognosis and a high mortality. Extracorporeal cardiopulmonary resuscitation (eCPR) using arteriovenous extracorporeal membrane oxygenation (av-ECMO) systems is an additional option for treatment, which is increasingly more widespread and since 2020 anchored in the guideline algorithm.

METHODS

A selective search of the literature was carried out in PubMed and Embase focusing on studies that investigated eCPR for OHCA. Furthermore, clinical studies on this topic that are currently recruiting and running are summarized.

RESULTS

The available data on the benefits of eCPR for OHCA are mostly based on retrospective cohort studies. A survival advantage and an advantage in the neurological outcome could be derived from these data for selected patients treated with eCPR vs. conventionally resuscitated patients (CPR). This effect could be confirmed by two current randomized controlled studies. Studies which are currently running are investigating if out-of-hospital ECMO cannulation at the earliest time possible at the site of OHCA of patients could be associated with a better survival.

CONCLUSION

Despite a current scarcity of data, a survival advantage for eCPR treatment in selected OHCA patients must be assumed. If this can be substantiated by other high-quality studies, it seems to be indicated to evaluate if and to what extent resource-intensive eCPR programs can be comprehensively established.

Association between herpes simplex virus Types 1 and 2 with cardiac myxoma

Most cases of atrial myxoma are sporadic, and the exact etiology is unknown. We examined if herpes simplex virus (HSV)-1 and HSV-2 antigens and/or DNA could be detected in a cohort of Iranian patients with cardiac myxomas. From July 2004 to June 2014, among a total of 36,703 patients undergoing open heart surgeries, consecutive patients with cardiac myxoma who were treated by surgical excision at our center included in this study. Of 73 patients studied, 56% were female with a mean age of 54 years (ranging from 23 to 77 years). Seventy-four myxomas were surgically removed from 73 patients, since one patient had two myxomas which were located on both the right atrium and right ventricle. The materials for this analysis were retrospectively gathered from extracted tumors that stored in a pathology bank of tissue paraffin blocks. The formalin fixed paraffin embedded tissue samples were investigated for HSV genomic DNA by both immunohistochemistry (IHC) and polymerase chain reaction (PCR) analysis. In all 74 cases there was no presence of HSV 1 and HSV 2 infection. This suggests that HSV may not play a role in sporadic cardiac myxomas; however, evidence for such association is currently lacking, and further studies are required to determine such a role.

Atrial myxoma: a rare cause of hemiplegia in children

Background:

Atrial myxoma is an uncommon cause of hemiplegia in children. However hemiplegia is the commonest manifestation of atrial myxoma in the paediatric age group.

Case report:

An 11-year-old girl presented with left hemiplegia and palpitations. Three months later she had a deepvein thrombosis of the right common iliac vein. MRI of the brain showed a subacute right thalamic infarct, and an ECG showed left atrial and left ventricular hypertrophy. Transthoracic echocardiography revealed a left atrial myxoma impinging on the mitral valve. A diagnosis of left atrial myxoma with multiple thromboembolic events was made. She was placed on anticoagulants until she died while awaiting surgical tumour resection.

Conclusion:

Echocardiography should be done early in children presenting with ischaemic thromboembolic diseases in order to reduce morbidity and mortality rates resulting from cardiac pathology.

PPARγ suppresses the proliferation of cardiac myxoma cells through downregulation of MEF2D in a miR-122-dependent manner

Peroxisome proliferator-activated receptor gamma (PPARγ), a multiple functional transcription factor, has been reported to have anti-tumor effects through inhibition of cells proliferation. However, its effects on cardiac myxoma (CM) cells and the underlying signaling mechanism is unclear. In the present study, we demonstrated that the level of PPARγ is inversely correlated with that of myocyte enhancer factor 2D (MEF2D), a biomarker of CM. We found that activation of PPARγ inhibit MEF2D expression via upregulation of miR-122, which can target the 3'-UTR of MEF2D and inhibit MEF2D expression, by directly binding to the PPRE in the miR-122 promoter region. Functional experiments further showed that miR-122-dependent downregulation of MEF2D by PPARγ suppress the proliferation of CM cells. These results suggest that PPARγ may exert its antiproliferative effects by negatively regulating the MEF2D in CM cells, which through upregulation of miR-122, and PPARγ/miR-122/MEF2D signaling pathway may be a novel target for treatment of CM.

The Critical Role of Rab31 in Cell Proliferation and Apoptosis in Cancer Progression

Rab31, a member of the Ras superfamily, is reported to play a role in tumor development and progression. However, the detailed role of Rab31 in proliferation and apoptosis of cancer cells is still unclear. Here, we used different cell lines, such as glioblastoma, and cervical cancer, to investigate the role of Rab31 in cancer progression. We found that Rab31 promotes U87 and SiHa cell proliferation via activation of G1/S checkpoint transitions, accompanied with an increase of cyclin D1, cyclin A, and cyclin B1. Meanwhile, Rab31 inhibits U87 and SiHa cell apoptosis, and decreased the BAX and PIG3 expression, but enhanced BCL2 expression. In addition, Rab31 induces N-cadherin, Vimentin, and Snail expression, and inhibits E-cadherin expression to regulate proliferation and migration. Besides, we observed that ERK1/2 and PI3k/AKT pathways are required for Rab31-induced cell proliferation and migration. In vivo, the knockdown of Rab31 suppresses tumor mass growth. In conclusion, our data highlight the crucial role of Rab31 in cancer progression, proliferation, and apoptosis, and indicates that Rab31 may be a useful and effective target for the clinical therapy of most cancers.

Astrocyte-elevated gene-1 mediates insulin-like growth factor 1-induced the progression of cardiac myxoma

Recently, astrocyte-elevated gene-1 (AEG-1) and insulin-like growth factor 1 (IGF-1) have been involved in the regulation of multiple signaling pathways in tumorigenesis. To date, the detailed mechanisms underlying IGF-1-AEG-1 pathway-induced proliferation and apoptosis in cardiac myxoma (CM) was not reported. In the present study, we used immnohistochemistry, immunoblotting, and qRT-PCR to detect the expression profile of IGF-1 and AEG-1 in 90 CM tissues, and then cultured CM cells were subjected to si-AEG-1, in vitro, and in vivo assays. Our findings showed that IGF-1 and AEG-1 were obviously upregulated in CM tissues and markedly associated with tumor size. When CM cells were treated with si-AEG-1, si-AEG-1 attenuated IGF-1-induced CM cell growth and enhanced cell apoptosis. Mechanically, we validated the expression of AEG-1, p-Erk1/2, and p-Akt increased in CM cells in response to IGF-1 treatment in a time-dependent manner. However, si-AEG-1 affected the expression of these proteins. Functionally, we found the knockdown of AEG-1-inhibited G1/S transition and tumor formation of CM cells. In conclusion, AEG-1 regulates IGF-1-induced proliferation and apoptosis via Erk1/2 and Akt signaling in CM development, which suggests IGF-1-AEG-1 signaling could be recommended to be a useful target to exert anti-tumor effects on CM.

Astrocyte elevated gene-1 regulates CCL3/CCR5-induced epithelial-to-mesenchymal transition via Erk1/2 and Akt signaling in cardiac myxoma

In recent years, astrocyte elevated gene-1 (AEG-1) has been reported as a key mediator that is involved in the epithelial-to-mesenchymal transition (EMT) process. However, the mechanisms underlying CCL3/CCR5-AEG-1 pathway-mediated EMT in cardiac myxoma (CM) has not been well featured till now. We used immnohistochemistry and immunoblotting to assess the expression of CCR5 and AEG-1 in 30 cases of CM tissues and cells. Subsequently, cultured CM cells were treated with si-AEG-1 or si-CCR5 and then subjected to in vitro assays. We observed that CCR5 and AEG-1 proteins were highly expressed in CM tissues (73.3 and 76.7%, respectively) and closely correlated with tumor size (>5 cm). Importantly, we validated the expression of AEG-1, p-Erk1/2, p-Akt, vimentin, N-cadherin and MMP2 increased in the CM cell with CCL3 treatment in a time- and concentration-dependent manner. When CM cells were treated with si-CCR5, the expression of AEG-1, p-Erk1/2, p-Akt, vimentin, N-cadherin and MMP2 was downregulated. In addition, when CM cells were treated with si-AEG-1, the expression of p-Erk1/2, p-Akt, vimentin, N-cadherin and MMP2 was also downregulated. Using the cell cycle and proliferation assay, the knockdown of AEG-1 inhibited the entry of G1 into S phase and the proliferation capacity of CM cells. In conclusion, AEG-1 mediates CCL3/CCR5-induced EMT development via both Erk1/2 and Akt signaling pathway in CM patients, which indicates CCL3/CCR5-AEG-1-EMT pathway could be suggested as a useful target to affect the progression of CM.

[Histopathological and immunohistochemical features of cardiac myxomas]

Mixomas are the most common primary cardiac tumors with an estimate incidence of 0,5-1 per 10(6) individuals per year. These tumors have generated interest due to their unique location (left side of the atrial septum near the fossa ovalis), variable clinical presentation and undefined histogenesis. Most cardiac myxomas occur sporadically while approximately 10% of diagnosed cases develop as part of Carney complex. This neoplasm is of uncertain histogenesis, however, endothelial, neurogenic, fibroblastic, and cardiac and smooth muscle cells differentiation has been proposed, and rarely glandular differentiation has been observed. Recently, due to the expression of certain cardiomyocyte-specific factors, an origin of mesenchymal cardiomyocytes progenitor cells has been suggested. Histologically cardiac myxomas are mainly composed of stellated, fusiform and polygonal cells, immersed in an amorphous myxoid matrix. Immunohistochemically some endothelial markers, such as CD31, CD34, FVIIIAg, are present. Positive staining has also been reported for S-100 protein, calretinin, vimentin, desmin, smooth muscle myosin, CD56, α1 antitrypsin and α 1antichymotrypsin. Surgical resection is currently the only treatment of choice. We present in this article a histopathological and immunohistochemical review of cardiac myxomas.

A case of comorbid myxoma and chronic lymphocytic leukemia: not just a coincidence?

Background. It is unclear why cardiac myxomas develop. We describe a case of comorbid myxoma and chronic lymphocytic leukemia (CLL) to offer insights into the tumor's pathophysiology. Case. A 56-year-old female with recurrent venous thromboembolism developed embolic stroke. Transesophageal echocardiogram showed a 1.7 × 1 cm sessile left atrial mass at the interatrial septum. Histopathology revealed myxoma with a B cell lymphocytic infiltrate suggestive of a low grade lymphoproliferative disorder. Bone marrow biopsy and flow cytometry of blood and the cardiac infiltrate supported the diagnosis of atypical CLL. She was followed clinically in the absence of symptoms, organ infiltration, or cytopenia. After eighteen months, she developed cervical and axillary lymphadenopathy. Biopsy confirmed B cell CLL/small lymphocytic lymphoma. She elected to undergo chemotherapy with fludarabine, cyclophosphamide, and rituximab, with clinical remission. Conclusions. The coexistence of two neoplastic processes may be coincidental, but the cumulative likelihood is estimated at 0.002 per billion people per year. A shared pathogenic mechanism is more likely. Possibilities include chronic inflammation, vascular endothelial growth factor A, shared genetic mutations, changes in posttranslational regulation, or alterations in other cellular signaling pathways. Additional studies could expand our current understanding of the molecular biology of both myxomas and CLL.

Molecular basis of cardiac myxomas

Cardiac tumors are rare, and of these, primary cardiac tumors are even rarer. Metastatic cardiac tumors are about 100 times more common than the primary tumors. About 90% of primary cardiac tumors are benign, and of these the most common are cardiac myxomas. Approximately 12% of primary cardiac tumors are completely asymptomatic while others present with one or more signs and symptoms of the classical triad of hemodynamic changes due to intracardiac obstruction, embolism and nonspecific constitutional symptoms. Echocardiography is highly sensitive and specific in detecting cardiac tumors. Other helpful investigations are chest X-rays, magnetic resonance imaging and computerized tomography scan. Surgical excision is the treatment of choice for primary cardiac tumors and is usually associated with a good prognosis. This review article will focus on the general features of benign cardiac tumors with an emphasis on cardiac myxomas and their molecular basis.

The value of coronary angiography in the work-up of atrial myxomas

Atrial myxomas are the most common primary cardiac tumors. They are highly vascular with evidence of neovascularization and a characteristic"tumor blush" in approximately half of the cases. Although the visualization of feeding vessels has several clinical and therapeutic implications, there is still no consensus on the indication of preoperative coronary angiography to assess tumor vascularity except in patients with angina or those older than 40 years to rule out coronary artery disease. Herein, I present a case of an incidentally discovered right atrial mass receiving vascular supply from the right coronary artery. The mass was successfully excised and the diagnosis of cardiac myxoma was confirmed via histopathology. A review of the value of coronary angiography in detecting myxoma neovascularization is provided, which suggests that it can offer additional valuable information that can alter the surgical approach and therefore may be considered prior to myxoma resection.

Cardiac myxoma induced paraneoplastic syndromes: a review of the literature

BACKGROUND

Atrial myxomas are the most common benign tumors of the heart and may present with a wide variety of symptoms. Although 45% of patients present with neurological symptoms, a diverse range of systemic symptoms also occur.

METHODS

A systemic review of the literature related to the diagnosis, treatment, pathogenesis, and symptoms associated with atrial myxomas was performed.

RESULTS

Here we summarize the current state of understanding about myxoma pathogenesis and treatments are described. We review the common and rare local and systemic effects of myxomas. Additionally, we review the paraneoplastic and metastatic potential of myxomas.

CONCLUSIONS

A better understanding of the diverse disease presentations, paraneoplastic syndromes, and side effects of cytokine abnormalities stemming from myxomas will aid the physician in earlier detection and monitoring of disease recurrence.

Urotensin II stimulates vascular endothelial growth factor secretion from adventitial fibroblasts in synergy with angiotensin II

BACKGROUND

The adventitia plays an important role in and is considered to be the initiating site for vascular remodeling. Urotensin II (UII) and angiotensin II (Ang II) are the two most important vascular peptides involved in vascular remodeling in the adventitia. Nevertheless, little is known about their effect on the expression of vascular endothelial growth factor (VEGF). It was hypothesized that both UII and Ang II could induce VEGF expression in adventitial fibroblasts and VEGF may play a role in cell proliferation and collagen I synthesis induced by UII or Ang II.

METHODS AND RESULTS

Growth-arrested adventitial fibroblasts were incubated in serum-free medium with UII and/or Ang II and inhibitors of the mitogen-activated protein kinase (MAPK) pathway or VEGF-neutralizing antibodies. The VEGF expression was evaluated using enzyme-linked immunosorbent assay (ELISA), while the proliferation and collagen I synthesis were detected using methyl thiazol tetrazolium (MTT) assay and ELISA. It was found that: (1) both UII and Ang II could stimulate VEGF expression in adventitial fibroblasts and they had a synergistic effect; (2) MAPK pathway inhibitors could inhibit VEGF secretion induced by UII and/or Ang II; and (3) VEGF-neutralizing antibodies could inhibit UII/Ang II-induced cell proliferation and collagen synthesis in adventitial fibroblasts.

CONCLUSIONS

Induction of VEGF expression may be a new mechanism involved in vascular remodeling for UII and Ang II.

Atrial myxoma and bone changes: a paraneoplastic syndrome?

Atrial myxomas are the most common benign tumors of the heart and are difficult to diagnose due to a wide variety of presenting symptoms. We present a patient with a five-year history of visual loss, vertigo, ataxia, tinnitus, and bone lesions that resolved after diagnosis and resection of an atrial myxoma. This case not only highlights an unusual presentation of atrial myxomas but also raises the question of whether atrial myxomas can produce paraneoplastic syndromes, including bone abnormalities. 

Overexpression of alternatively spliced tissue factor induces the pro-angiogenic properties of murine cardiomyocytic HL-1 cells

BACKGROUND

Tissue factor (TF) is expressed in 2 isoforms: membrane-bound "full length" (fl)TF and soluble alternatively spliced (as)TF. flTF is the major thrombogenic form of TF. Although the function of asTF is poorly understood, it was suggested that asTF contributes to tumor-associated growth and angiogenesis. In the heart of a developing embryo, asTF is expressed much later compared to flTF, but in adult heart, asTF exhibits a distribution pattern similar to that of flTF. Thus, it is possible that asTF may play a role in heart development via pro-angiogenic signaling. The purpose of the present study was to examine the effects of murine asTF overexpression in murine cardiomyocyte-like HL-1 cells on their pro-angiogenic potential, the chemotaxis of monocytic cells, and the expression of fibroblast growth factor-2 (FGF2), cysteine-rich 61 (Cyr61), and vascular endothelial growth factor (VEGF).

METHODS AND RESULTS

Expression of FGF2, Cyr61 and VEGF was assessed on reverse transcription-polymerase chain reaction and western blot. Cell migration, proliferation, and endothelial tube formation assays were carried out. It was found that overexpression of murine asTF in HL-1 cells increases their proliferation and pro-angiogenic properties. The supernatant of murine asTF-overexpressing HL-1 cells induces the chemotaxis of monocytic cells.

CONCLUSIONS

Overexpression of murine asTF in murine cardiomyocytic cells increases their proliferation, monocyte migration, and pro-angiogenic properties -possibly- mediated by the induction of the pro-migratory and pro-angiogenic factors FGF2, Cyr61 and VEGF. Thus, we propose that murine asTF may serve as a migration- and angiogenesis-promoting factor.

A novel kind of tumor type-characteristic junction: plakophilin-2 as a major protein of adherens junctions in cardiac myxomata

Using novel antibodies of high avidity to--and specificity for--the constitutive desmosomal plaque protein, plakophilin-2 (Pkp2), in a systematic study of the molecular composition of junctions connecting the cells of soft tissue tumors, we have discovered with immunocytochemical, biochemical and electron microscopical methods, a novel type of adherens junctions in all 32 cardiac myxomata examined. These junctions contain cadherin-11 as their major transmembrane glycoprotein, which we could repeatedly show in colocalization with N-cadherin, anchored in a cytoplasmic plaque formed by α- and β-catenin, together with the further armadillo-type proteins plakoglobin, p120, p0071 and ARVCF. Surprisingly, all adherens junctions of these tumors contained, in addition, another major armadillo protein Pkp2, hitherto known as an obligatory and characteristic constituent of desmosomes in epithelium-derived tumors. We have not detected Pkp2 in a series of noncardiac myxomata studied in parallel. Therefore, we conclude that this acquisition of Pkp2, which we have recently also observed in some mesenchymally derived cells growing in culture, can also occur in tumorigenic transformations in situ. We propose to examine the marker value of Pkp2 in clinical diagnoses of cardiac myxomata and to develop Pkp2-targeted therapeutic reagents.

Systemic embolisation as presentation and recurrence of cardiac myxoma two years after surgery

Primary cardiac tumours are rare when compared with metastatic involvement. The majority of primary cardiac tumours are benign and in adults the majority of these masses are myxomas. The treatment is surgical removal because of the risk of embolisation and/or cardiovascular complications. We describe a female presenting with systemic embolisation and recurrence of cardiac myxoma after surgery. Recurrence of myxoma is rare after surgery in case of solitary tumours but more frequent in patients with familial myxomas in association with the Carney complex. Genetic analysis revealed a mutation in the PRKAR1A gene that has never been described before. (Neth Heart J 2010;18:499502.).

Potential autocrine function of vascular endothelial growth factor in head and neck cancer via vascular endothelial growth factor receptor-2

Vascular endothelial growth factor is a peptide with well-defined actions on the vasculature and fundamental role in tumor angiogenesis. Its action in vascular endothelium is exerted in a paracrine manner. The immunohistochemical expression of this protein by cancer cells in head and neck squamous cell carcinoma was correlated with increased tumor aggressiveness and poor survival in previous studies. In the past years, an increasing amount of studies demonstrated potential autocrine action of vascular endothelial growth factor in various neoplasms. However, the existence and the impact of such autocrine action in head and neck cancer have not been demonstrated yet. In this retrospective study, we evaluated the expression of vascular endothelial growth factor and its receptors in neoplastic cells, in a cohort of patients with head and neck squamous cell carcinoma, and compared this expression with tumor aggressiveness, clinicopathologic parameters and outcome. High expression of vascular endothelial growth factor was strongly correlated with high expression of vascular endothelial growth factor receptor-2 (but not vascular endothelial growth factor receptor-1) on the cancer cells (P<0.001). The co-overexpression of both the protein and vascular endothelial growth factor receptor-2 was associated with higher tumor proliferation rate (P<0.001). The above co-overexpression also correlated with worse survival (log rank P<0.05) in patients with oral-larynx squamous cell carcinoma. Our results suggest that an autocrine vascular endothelial growth factor loop, mediated via vascular endothelial growth factor receptor-2, probably exists in head and neck squamous cell carcinoma. These observations support the hypothesis that the use of vascular endothelial growth factor receptor-2 inhibitors as adjuvant antiangiogenic therapy might have beneficial effects for these patients, by disrupting both paracrine (endothelial-dependent) and autocrine actions of vascular endothelial growth factor.

Mechanism of Myocardial Microvessel Formation in Cyanotic Congenital Heart Disease

BACKGROUND

Patients with cyanotic congenital heart disease (C-CHD) usually have myocardial thickening and fibrosis, both of which can affect the course of surgical management. Hypoxia and ischemia may stimulate microvessel formation in the myocardium, which may accelerate the myocardial thickening and fibrosis. Whether hyperplasia of microvessels occurs in the myocardium of C-CHD was investigated in this report.

METHODS AND RESULTS

The patients were divided into 2 groups; the C-CHD group (n = 22), and the acyanotic congenital heart disease (A-CHD) group (n = 24). The microvessels and vascular endothelial growth factor (VEGF) mRNA of the myocardium were detected by immunohistochemical staining assay and real-time quantitative reverse transcriptase polymeric chain reaction, respectively. The serum VEGF levels were measured by using enzyme-linked immunosorbent assay. The results were that: (1) the number of microvessels in the myocardium were more in the C-CHD group than in A-CHD group; (2) the serum VEGF levels in the C-CHD group vs the A-CHD group were higher in the preoperative period (p < 0.001), but there was no difference after operation; and (3) VEGF protein and the expression of VEGF mRNA in the myocardium were higher in the C-CHD group than in the A-CHD group (p < 0.01).

CONCLUSIONS

Myocardial microvessels formed in the myocardium of patients with C-CHD, possibly mediated by increasing VEGF levels (for this group of patients).

Production of Endothelin-1 and Big Endothelin-1 by Human Cardiac Myxoma Cells-Implications for the Origin of Myxomas-

BACKGROUND

Although the origin of cardiac myxomas is still controversial, the 2 main hypotheses are that the tumor cells originate either from multipotential mesenchymal cells or from endocardial neural tissue.

METHODS AND RESULTS

The production of various cytokines in 2 human cardiac myxoma cell lines was examined by enzyme-linked immunosorbent assay. After 7 days of culture, extremely high concentrations of interleukin-6 were detected in the culture media from both myxoma cell lines. Increased production of CXC chemokines, interleukin-8 and growth-related oncogene-alpha, were observed in both myxoma cell lines. Endothelin (ET)-1 and its precursor, big ET-1, were detected in the culture media from both myxoma cell lines. The production of both ET-1 and big ET-1 by myxoma cells was higher than by human umbilical vein endothelial cells. Similar to endothelial cells, myxoma cells did not produce stem cell factor, granulocyte colony-stimulating factor, hepatocyte growth factor, or ET-3.

CONCLUSIONS

The similarity of the cytokine production pattern between cardiac myxoma cells and endothelial cells supports the hypothesis that the tumor cells originate from mesenchymal cells capable of endothelial differentiation. Overproduction of CXC chemokines may explain, in part, the malignant potential of histologically benign myxomas.