Cancer Stem Cells in Glioblastoma Multiforme

Aim

To identify and characterize cancer stem cells (CSC) in glioblastoma multiforme (GBM).

Methods

Four-micrometer thick formalin-fixed paraffin-embedded GBM samples from six patients underwent 3,3-diaminobenzidine (DAB) and immunofluorescent (IF) immunohistochemical (IHC) staining for the embryonic stem cell (ESC) markers NANOG, OCT4, SALL4, SOX2, and pSTAT3. IF IHC staining was performed to demonstrate co-expression of these markers with GFAP. The protein expression and the transcriptional activities of the genes encoding NANOG, OCT4, SOX2, SALL4, and STAT3 were investigated using Western blotting (WB) and NanoString gene expression analysis, respectively.

Results

DAB and IF IHC staining demonstrated the presence of a CSC population expressing NANOG, OCT4, SOX2, SALL4, and pSTAT3 with the almost ubiquitous presence of SOX2 and a relatively low abundance of OCT4, within GBM. The expression of NANOG, SOX2 and, pSTAT3 but, not OCT and SALL4, was confirmed by WB. NanoString gene analysis demonstrated transcriptional activation of NANOG, OCT4, SALL4, STAT3, and SOX2 in GBM.

Conclusion

This study demonstrated a population of CSCs within GBM characterized by the expression of the CSC markers NANOG, SALL4, SOX2, pSTAT3 and OCT4 at the protein and mRNA levels. The almost ubiquitous presence of SOX2 and a relatively low abundance of OCT4 would support the putative existence of a stem cell hierarchy within GBM.

Characterization of Cancer Stem Cells in Moderately Differentiated Buccal Mucosal Squamous Cell Carcinoma

Aim

To identify and characterize cancer stem cells (CSC) in moderately differentiated buccal mucosa squamous cell carcinoma (MDBMSCC).

Methods

Four micrometer-thick, formalin-fixed, paraffin-embedded MDBMSCC samples from six patients underwent 3,3-diaminobenzidine (DAB) immunohistochemical (IHC) staining for the embryonic stem cell (ESC) markers, NANOG, OCT4, SALL4, SOX2, and pSTAT3; cancer stem cell marker, CD44; squamous cell carcinoma (SCC) marker, EMA; and endothelial marker, CD34. The transcriptional activities of the genes encoding NANOG, OCT4, SOX2, SALL4, STAT3, and CD44 were studied using NanoString gene expression analysis and colorimetric in situ hybridization (CISH) for NANOG, OCT4, SOX2, SALL4, and STAT3.

Results

Diaminobenzidine and immunofluorescent (IF) IHC staining demonstrated the presence of (1) an EMA⁺/CD44⁺/SOX2⁺/SALL4⁺/OCT4⁺/pSTAT3⁺/NANOG⁺ CSC subpopulation within the tumor nests; (2) an EMA⁻/CD44⁻/CD34⁻/SOX2⁺/OCT4⁺/pSTAT3⁺/NANOG⁺ subpopulation within the stroma between the tumor nests; and (3) an EMA⁻/CD44⁻/CD34⁺/SOX2⁺/SALL4⁺/OCT4⁺/pSTAT3⁺/NANOG⁺ subpopulation on the endothelium of the microvessels within the stroma. The expression of CD44, SOX2, SALL4, OCT4, pSTAT3, and NANOG was confirmed by the presence of mRNA transcripts, using NanoString analysis and NANOG, OCT4, SOX2, SALL4, and STAT3 by CISH staining.

Conclusion

This study demonstrated a novel finding of three separate CSC subpopulations within MDBMSCC: (1) within the tumor nests expressing EMA, CD44, SOX2, SALL4, OCT4, pSTAT3, and NANOG; (2) within the stroma expressing SOX2, SALL4, OCT4, pSTAT3, and NANOG; and (3) on the endothelium of the microvessels within the stroma expressing CD34, SOX2, SALL4, OCT4, pSTAT3, and NANOG.

Expression of the Components of the Renin-Angiotensin System in Venous Malformation

BACKGROUND

Venous malformation (VM) is the most common form of vascular malformation, consisting of a network of thin-walled ectatic venous channels with deficient or absent media. This study investigated the expression of the components of the renin-angiotensin system (RAS), namely, (pro)renin receptor (PRR), angiotensin-converting enzyme (ACE), angiotensin II receptor 1 (ATIIR1), and angiotensin II receptor 2 (AIITR2) in subcutaneous (SC) and intramuscular (IM) VM.

MATERIALS AND METHODS

SC (n = 7) and IM (n = 7) VM were analyzed for the expression of PRR, ACE, ATIIR1, and ATIIR2 using 3,3-diaminobenzidine and immunofluorescent (IF) immunohistochemical (IHC) staining and NanoString gene expression analysis.

RESULTS

IHC staining showed expression of PRR, ACE, and ATIIR1, and faint expression of ATIIR2 in the endothelium of SC and IM VM. Furthermore, ATIIR2 was expressed by cells away from the endothelium in both SC and IM VM lesions examined. NanoString analysis demonstrated the presence of PRR, ACE, and ATIIR1 but not ATIIR2.

CONCLUSION

The presence of PRR, ACE, ATIIR1, and potentially ATIIR2, in both SC and IM VM, suggests a role for the RAS in the biology of VM. This novel finding may lead to a mechanism-based therapy for VM.

Cancer Stem Cell Hierarchy in Glioblastoma Multiforme

Glioblastoma multiforme (GBM), an aggressive tumor that typically exhibits treatment failure with high mortality rates, is associated with the presence of cancer stem cells (CSCs) within the tumor. CSCs possess the ability for perpetual self-renewal and proliferation, producing downstream progenitor cells that drive tumor growth. Studies of many cancer types have identified CSCs using specific markers, but it is still unclear as to where in the stem cell hierarchy these markers fall. This is compounded further by the presence of multiple GBM and glioblastoma cancer stem cell subtypes, making investigation and establishment of a universal treatment difficult. This review examines the current knowledge on the CSC markers SALL4, OCT-4, SOX2, STAT3, NANOG, c-Myc, KLF4, CD133, CD44, nestin, and glial fibrillary acidic protein, specifically focusing on their use and validity in GBM research and how they may be utilized for investigations into GBM's cancer biology.

Expression of embryonic stem cell markers in keloid-associated lymphoid tissue

AIMS

To identify, characterise and localise the population of primitive cells in keloid scars (KS).

METHODS

5-µm-thick formalin-fixed paraffin-embedded sections of KS samples from 10 patients underwent immunohistochemical (IHC) staining for the embryonic stem cell (ESC) markers OCT4, SOX2, pSTAT3 and NANOG, and keloid-associated lymphoid tissue (KALT) markers CD4 and CD20. NanoString gene expression analysis and in situ hybridisation (ISH) were used to determine the abundance and localisation of the mRNA for these ESC markers.

RESULTS

IHC staining revealed the expression of the ESC markers OCT4, SOX2, pSTAT3 and NANOG by a population of cells within KS tissue. These are localised to the endothelium of the microvessels within the KALTs. NanoString gene expression analysis confirmed the abundance of the transcriptional expression of the same ESC markers. ISH localised the expression of the ESC transcripts to the primitive endothelium in KS tissue.

CONCLUSIONS

This report demonstrates the expression of ESC markers OCT4, SOX2, pSTAT3 and NANOG by the endothelium of the microvessels within the KALTs. These findings show a unique niche of primitive cells within KS, expressing ESC markers, revealing a potential therapeutic target in the treatment of KS.

Elevated Serum Levels of Alpha-Fetoprotein in Patients with Infantile Hemangioma Are Not Derived from within the Tumor

Aims

The embryonic-like stem cell origin of infantile hemangioma (IH) and the observed elevated serum levels of alpha-fetoprotein (AFP) in patients with hepatic IH led us to investigate if this tumor was the source of AFP.

Materials and methods

We measured serial serum levels of AFP in patients with problematic proliferating IH treated with surgical excision or propranolol treatment. We also investigated the expression of AFP in extrahepatic IH samples using immunohistochemical staining, mass spectrometry, NanoString gene expression analysis, and in situ hybridization.

Results

Serum levels of AFP normalized following surgical excision or propranolol treatment. Multiple regression analysis for curve fittings revealed a different curve compared to reported normal values in the general populations. AFP was not detected in any of the IH samples examined at either the transcriptional or translational levels.

Conclusion

This study demonstrates the association of proliferating IH with elevated serum levels of AFP, which normalized following surgical excision or propranolol treatment. We have shown that IH is not the direct source of AFP. An interaction between the primitive mesoderm-derived IH and the endogenous endodermal tissues, such as the liver, via an intermediary, may explain the elevated serum levels of AFP in infants with extrahepatic IH.

PHACE syndrome--clinical features, aetiology and management

PHACE syndrome comprises a spectrum of anomalies including posterior fossa malformations, haemangioma, arterial anomalies, cardiac defects and eye anomalies. PHACE should be considered in any patient with a large facial segmental infantile haemangioma (IH), and multidisciplinary management is crucial. Low-dose propranolol is effectively for the treatment of IH associated with PHACE syndrome. Recent evidence suggests IH is comprised of mesoderm-derived haemogenic endothelium.

CONCLUSION

The embryonic developmental anomaly nature of IH provides an insight into the origin of PHACE syndrome.

Expression of Cathepsins B, D, and G in Infantile Hemangioma

AIMS

The role of the renin-angiotensin system (RAS) in the biology of infantile hemangioma (IH) represents an emerging paradigm, particularly the involvement of renin, angiotensin converting enzyme, and angiotensin II. This study investigated the expression of cathepsins B, D, and G, enzymes that may modulate the RAS, in IH.

MATERIALS AND METHODS

The expression of cathepsins B, D, and G was examined using immunohistochemistry, enzyme activity assays, mass spectrometry, and NanoString gene expression assay in IH samples at different phases of development.

RESULTS

Immunohistochemical staining showed the expression of cathepsins B, D, and G in proliferating and involuted IH samples. This was confirmed at the transcriptional level using NanoString gene expression assays. Mass spectrometry confirmed the identification of cathepsins D and G in all three phases of IH development, whereas cathepsin B was detected in 2/2 proliferating and 1/2 involuting lesions. Enzyme activity assays demonstrated the activity of cathepsins B and D, but not G, in all phases of IH development.

CONCLUSION

Our data demonstrated the presence of cathepsins B, D, and G in IH. Their role in modulating the RAS and the biology of IH offers potential novel targets for the management of this tumor.

Outcomes of the treatment of head and neck sarcomas in a tertiary referral center

Head and neck sarcomas are a rare and heterogeneous group of tumors that pose management challenges. We report our experience with these tumors. Forty consecutive patients treated for 44 head and neck sarcomas between 1997 and 2014 were culled from our prospectively maintained head and neck database. Five patients were excluded. The adult cohort consisted 29 (83%) patients of a mean age of 57.7 years, with 33 sarcomas. The most common diagnoses were undifferentiated pleomorphic sarcoma (27%) and chondroblastic osteosarcoma (21%). Clear surgical margins were achieved in 24/33 (73%) lesions. Twenty-two patients received radiotherapy and/or chemotherapy. Fourteen patients developed local (n = 6), regional (n = 1) and distant (n = 7) recurrence. The overall 5-year survival was 66% with a mean survival interval of 66.5 months. Recurrent sarcoma, close (<1 mm) or involved surgical margins and advanced age were associated with statistically significantly reduced survival. The pediatric cohort consisted 6 (17%) patients, with a mean age of 9 years. Five patients had primary embryonal rhabdomyosarcomas and one had chondroblastic osteosarcoma. Clear surgical margins were achieved in five (83%) patients. All patients received adjuvant radiotherapy and/or chemotherapy. Mean survival interval was 102 months. Three patients developed local (n = 1) or distant (n = 2) recurrence. Twenty-three free and 8 pedicled flaps were performed in 25 patients. Eleven out of thirty-nine (28%) lesions in 11 patients developed a complication. In conclusion, head and neck sarcomas are best managed by a multidisciplinary team at a tertiary head and neck referral center and resection with clear margins is vital for disease control.

Angiolymphoid hyperplasia with eosinophilia developing within a port wine stain

A 19-year-old male with a port wine stain on the base of his neck presented with a 5-month history of gradual thickening of the involved skin which interfered with clothing and caused repeated bleeding. The lesion was excised and histopathologic examination revealed angiolymphoid hyperplasia with eosinophilia (ALHE) arising from the pre-existing port wine stain - a rare finding with only one previously reported case. Additionally the lesion was associated with elevated serum renin levels which virtually normalized following excision of the lesion. We further demonstrated the expression of angiotensin converting enzyme and angiotensin II receptors 1 and 2 by the lesion and discuss the possible role of the renin-angiotensin system in this condition.

Low-dose propranolol regimen for infantile haemangioma

AIMS

Propranolol, now the preferred treatment for problematic proliferating infantile haemangioma (IH), at an empirical cardiovascular dosage of 2-3 mg/kg/day is associated with variable complication rates. A meta-analysis shows complications in 31% of patients at a mean dosage of 2.12 mg/kg/day. This study reports on the minimal dosage and duration of treatment to achieve accelerated involution and side effects using a stepwise escalation regimen.

METHODS

Consecutive patients with problematic proliferating IH treated with propranolol were identified from our vascular anomalies database. Propranolol was commenced at 0.5 mg/kg/day in two divided doses and increased to 1 mg/kg/day after 24 h. The patients were reviewed after 1 week, and the dosage was increased to 1.5 mg/kg/day. The dosage was further increased by 0.5 mg/kg/day, if necessary, to achieve accelerated involution.

RESULTS

Forty-four patients, aged 3 weeks to 11 months (mean, 3.8 months), received propranolol therapy for problematic proliferating IH. The minimal dosage required to achieve accelerated involution was 1.5-2 mg/kg/day. Treatment was maintained for an average of 9.3 months and discontinued at an average age of 14.2 months. Rebound growth occurred in the first patient of this series when propranolol was withdrawn at 7.5 months of age, requiring reinstitution of treatment. Slight rebound growth following cessation of treatment was observed in four other patients, but reinstitution of propranolol was not required. Minor complications were observed in three (6.8%) patients.

CONCLUSIONS

Propranolol at 1.5-2 mg/kg/day, administered in divided doses with stepwise escalation, is safe and effective for treating problematic proliferating IH. Treatment is continued to an average age of 14.2 months.

Prevalence and predictors of suicidality among medical students in a public university

BACKGROUND

Undergraduate medical students have been the most distressed group among the student population. Depression and anxiety have been found to be more prevalent in this group of students compared to others.

OBJECTIVE

This study was conducted to determine the prevalence and predictors of suicidality among undergraduate medical students in a public university.

METHODS

This was an analytical cross-sectional study, conducted in a public university in Selangor, Malaysia. Data were collected using self-administered questionnaires from January to February 2013, and analysed using the Statistical Package for Social Sciences Software (version 21).

RESULTS

Out of 625 undergraduate medical students, 537 (85.9%) participated in the study. The prevalence of the suicidality among undergraduate medical students was 7.0%. The significant predictors of suicidality based on multiple logistic regression were the respondent's lifetime suicide attempts (Adjusted Odds Ratio, AOR 10.4, 95% CI 2.7 to 40.9); depression (AOR 5.9, 95% CI 1.5 to 23.0); breaking off a steady love relationship (AOR 5.4, 95% CI 1.3 to 22.4); hopelessness (AOR 4.9, 95% CI 1.1 to 21.6); and something valued being lost or stolen (AOR 4.4, 95% CI 1.2 to 15.9).

CONCLUSION

These findings indicate that mental health care services should be strengthened at university level. The results show a need for an intervention programme to reduce suicidality among the undergraduate medical students.

Biology of infantile hemangioma

Infantile hemangioma (IH), the most common tumor of infancy, is characterized by an initial proliferation during infancy followed by spontaneous involution over the next 5-10 years, often leaving a fibro-fatty residuum. IH is traditionally considered a tumor of the microvasculature. However, recent data show the critical role of stem cells in the biology of IH with emerging evidence suggesting an embryonic developmental anomaly due to aberrant proliferation and differentiation of a hemogenic endothelium with a neural crest phenotype that possesses the capacity for endothelial, hematopoietic, mesenchymal, and neuronal differentiation. Current evidence suggests a putative placental chorionic mesenchymal core cell embolic origin of IH during the first trimester. This review outlines the emerging role of stem cells and their interplay with the cytokine niche that promotes a post-natal environment conducive for vasculogenesis involving VEGFR-2 and its ligand VEGF-A and the IGF-2 ligand in promoting cellular proliferation, and the TRAIL-OPG anti-apoptotic pathway in preventing cellular apoptosis in IH. The discovery of the role of the renin-angiotensin system in the biology of IH provides a plausible explanation for the programed biologic behavior and the β-blocker-induced accelerated involution of this enigmatic condition. This crucially involves the vasoactive peptide, angiotensin II, that promotes cellular proliferation in IH predominantly via its action on the ATIIR2 isoform. The role of the RAS in the biology of IH is further supported by the effect of captopril, an ACE inhibitor, in inducing accelerated involution of IH. The discovery of the critical role of RAS in IH represents a novel and fascinating paradigm shift in the understanding of human development, IH, and other tumors in general.

Ethanol sclerotherapy for venous malformation

BACKGROUND

Ethanol sclerotherapy (ES) is the preferred treatment for venous malformation (VM) with surgery playing an adjunctive role. Results of ES, however, are not well documented in the literature.

METHODS

VM patients were identified from our vascular anomalies database from 1996 to 2011. After treatment completion, patients completed questionnaires evaluating symptoms and their severity and effect on appearance, function and overall quality of life (QoL), before and >6 months after treatment, using visual analogue scales of 0-10. Patients rated their overall satisfaction with ES using a scale of 0-10.

RESULTS

Fifty-four (23.9%) of the 226 VM patients underwent a total of 90 ES sessions (average 1.7 sessions per patient). Complications occurred in 12 (22.2%) patients in 12 (13.3%) ES sessions. Minor complications occurred in nine (16.7%) patients including transient paraesthesia (n = 3), transient weakness of facial nerve branch(es) (n = 3), skin blistering (n = 2) and spontaneously healing ulceration (n = 1). Major complications occurred in three (5.6%) patients in three (3.3%) ES sessions including skin necrosis (n = 1), Horner's syndrome (n = 1) and finger paraesthesia with joint stiffness (n = 1). ES improved the severity of background pain, episodic pain, contour deformity and skin discoloration in 86.0%, 72.4%, 83.0% and 72.2% of patients respectively. It reduced the effect of VM on appearance, function and overall QoL in 69.8%, 73.0% and 64.3% of patients. Mean treatment satisfaction was 7.9 (range, 0-10).

CONCLUSION

ES reduces pain, contour deformity and skin discoloration, and improves appearance, function and QoL. Our complication rates are consistent with the literature.

The incidence and risk factors of metastasis for cutaneous squamous cell carcinoma--implications on the T-classification system

Cutaneous squamous cell carcinoma (cSCC) constitutes the most common cancer capable of metastasis. While the latest version of the American Joint Committee on Cancer guidelines represents a significant step forward in accurate staging of cSCC, several proven independent risk factors remain excluded. We review the current literature on the incidence and proven independent risk factors of metastasis for cSCC and proposes their full inclusion in the staging system for primary lesions.

Surgical treatment for venous malformation

Sclerotherapy is generally the preferred treatment for venous malformation (VM) with surgery usually playing an adjunctive role. This study presents our experience with surgical treatment of VMs. Consecutive patients were identified from our vascular anomalies database 1996-2011 and patient demographics, location of the lesion, type of tissue(s) affected and symptoms were analysed. The patients completed a questionnaire to assess the impact of surgery on the severity of symptoms, appearance, function and overall quality of life (QoL), using a visual analogue scale of 0 (no symptom) to 10 (maximal symptom). They also rated their overall satisfaction of treatment using a scale of 0 (complete dissatisfaction) to 10 (complete satisfaction). Fifty patients with VM underwent a total of 58 procedures. Complication occurred in six patients (9.7% of operations), including transient sensory loss (n=3) and permanent frontal branch palsy (n=1), haematoma formation (n=1) and minor wound dehiscence (n=1). At least 50% improvement in symptoms of background pain, acute episodic pain, contour deformity and skin discolouration occurred in 88.9%, 92.3%, 83.3% and 75.0% of patients, respectively. At least 50% improvement in the appearance, function and overall QoL occurred in 54.3%, 71.4% and 70.4% of patients, respectively. The mean overall patient satisfaction with the treatment was 8.9 (range, 1-10). Surgery remains an important treatment modality for selected patients with VM having low complication rates and high patient satisfaction. It improves the appearance, function and overall QoL for the majority of the patients by reducing the severity of pain, contour deformity and skin discolouration.

The future of the New Zealand plastic surgery workforce

AIMS

The New Zealand (NZ) plastic and reconstructive surgery (PRS) workforce provides reconstructive plastic surgery (RPS) public services from six centres. There has been little analysis on whether the workforce is adequate to meet the needs of the NZ population currently or in the future. This study analysed the current workforce, its distribution and future requirements.

METHODS

PRS manpower data, workforce activities, population statistics, and population modelling were analysed to determine current needs and predict future needs for the PRS workforce. The NZ PRS workforce is compared with international benchmarks. Regional variation of the workforce was analysed with respect to the population's access to PRS services. Future supply of specialist plastic surgeons is analysed.

RESULTS

NZ has a lower number of plastic surgeons per capita than comparable countries. The current NZ PRS workforce is mal-distributed. Areas of current and emerging future need are identified.

CONCLUSIONS

The current workforce mal-distribution will worsen with future population growth and distribution. Up to 60% of the NZ population will be at risk of inadequate access to PRS services by 2027. Development of PRS services must be coordinated to ensure that equitable and sustainable services are available throughout NZ. Strategies for ensuring satisfactory future workforce are discussed.

Mast cells in infantile haemangioma possess a primitive myeloid phenotype

AIMS

Recent reports on infantile haemangioma (IH) have demonstrated a primitive population of interstitial cells expressing the embryonic transcription factor, Nanog, with decreasing abundance during involution. In this report we investigated the expression of Nanog on mast cells in all three phases of IH progression.

METHODS

Paraffin-embedded sections of six proliferating, six involuting and six involuted IH lesions were used to investigate the expression of tryptase, Nanog, CD45, CD34 and GLUT-1 by immunostaining.

RESULTS

Mast cells, identified by their expression of tryptase, were located in the interstitium of IH lesions. 93%, 42% and 0% of these tryptase(+) cells also expressed Nanog, in proliferating, involuting and involuted IH, respectively.

CONCLUSIONS

The identification of an abundant population of tryptase(+)/Nanog(+) cells in IH is novel. The relative loss of Nanog expression as IH involutes may be a result of maturation and/or proliferation of these cells. This report supports the primitive nature of IH.

Verrucous hemangioma expresses primitive markers

BACKGROUND

Verrucous hemangioma (VH) presents clinically as a vascular malformation but has similar histopathologic features to infantile hemangioma. This study characterized the cell population within VH.

MATERIAL AND METHODS

Paraffin-embedded sections from two male patients with VH were processed for immunohistochemistry. The expression of SMA, CD34, glucose transporter-1 (Glut-1), D2-40, brachyury, angiotensin converting enzyme (ACE), Oct-4, hemoglobin ζ chain (HBZ), Wilms tumor protein (WT-1) and CD45 was examined.

RESULTS

The lymphatic marker, D2-40, was not expressed in VH, whereas Glut-1 was widely expressed in infantile hemangioma, it was only focally expressed by the endothelium of VH. The endothelium of VH expressed the primitive markers, Oct-4, brachyury and ACE. The primitive marker, WT-1, was expressed predominantly on the pericyte layer of both VH and infantile hemangioma. However, HBZ was only expressed in infantile hemangioma. CD45, a mature hematopoetic marker, was expressed by cells within the interstitium, away from the endothelium of VH and infantile hemangioma.

DISCUSSION

The expression of the primitive markers, Oct-4, brachyury and ACE on the endothelium, and WT-1 predominantly on the pericyte layer of VH shows a primitive microvascular phenotype similar to infantile hemangioma. However, the absence of the embryonic marker, HBZ, expressed only in first trimester placenta and in proliferating infantile hemangioma, suggests a different cellular origin. HBZ could be used to distinguish between the two conditions.