Prognostic role of microvessel density in patients with glioma

Evaluation of Microvascular Density in Glioblastomas in Relation to p53 and Ki67 Immunoexpression

Glioblastoma is the most aggressive tumor in the central nervous system, with a survival rate of less than 15 months despite multimodal therapy. Tumor recurrence frequently occurs after removal. Tumoral angiogenesis, the formation of neovessels, has a positive impact on tumor progression and invasion, although there are controversial results in the specialized literature regarding its impact on survival. This study aims to correlate the immunoexpression of angiogenesis markers (CD34, CD105) with the proliferation index Ki67 and p53 in primary and secondary glioblastomas. This retrospective study included 54 patients diagnosed with glioblastoma at the Pathology Department of County Emergency Clinical Hospital Târgu Mureș. Microvascular density was determined using CD34 and CD105 antibodies, and the results were correlated with the immunoexpression of p53, IDH1, ATRX and Ki67. The number of neoformed blood vessels varied among cases, characterized by different shapes and calibers, with endothelial cells showing modified morphology and moderate to marked pleomorphism. Neovessels with a glomeruloid aspect, associated with intense positivity for CD34 or CD105 in endothelial cells, were observed, characteristic of glioblastomas. Mean microvascular density values were higher for the CD34 marker in all cases, though there were no statistically significant differences compared to CD105. Mutant IDH1 and ATRX glioblastomas, wild-type p53 glioblastomas, and those with a Ki67 index above 20% showed a more abundant microvascular density, with statistical correlations not reaching significance. This study highlighted a variety of percentage intervals of microvascular density in primary and secondary glioblastomas using immunohistochemical markers CD34 and CD105, respectively, with no statistically significant correlation between evaluated microvascular density and p53 or Ki67.

Immunohistochemical Assessment of Microvessel Density in OSCC: Spatial Heterogeneity of Angiogenesis and Its Impact on Survival

(1) Background Oral squamous cell carcinomas (OSCC) are a common malignancy of the oral cavity and are often diagnosed when they have already spread to the regional lymph nodes. Advanced stages of cancer are characterized by the development of distant metastases. Angiogenesis, a hallmark of cancer, is known to contribute to cancer progression and metastasis. High microvessel density (MVD) has been linked to poor clinical outcomes in various types of cancer. (2) Methods: In this study, we aimed to investigate the spatial heterogeneity of blood vessels by comparing the tumor center and invasion front and to evaluate its prognostic value in OSCC. A total of 71 OSCC patient specimens were collected. The tissue was immunohistochemically stained using CD31 antibody to assess the MVD in the tumor center and the invasion front. Furthermore, the associations between the histopathological parameters, including MVD, disease-free survival (DFS), and overall survival (OS) were computed. (3) Results: In our study, we found a significantly higher presence of blood vessels at the invasion front of OSCCs compared to the tumor center. However, we did not observe any significant differences in MVD between different tumor stages. High intratumoral MVD was shown to be a positive prognostic factor for DFS (p = 0.047). (4) Conclusions: To the best of our knowledge, we were the first to analyze MVD as a prognostic factor by considering its spatial heterogeneity in OSCC. However, further studies are warranted to further elucidate the complexity of microvascular spatial heterogeneity and its influence on prognosis.

Implications of Cellular Immaturity in Necrosis and Microvascularization in Glioblastomas IDH-Wild-Type

Necrosis and increased microvascular density in glioblastoma IDH-wild-type are the consequence of both hypoxia and cellular immaturity. Our study aimed to identify the main clinical-imaging and morphogenetic risk factors associated with tumor necrosis and microvascular in the prognosis of patient survival. We performed a retrospective study (10 years) in which we identified 39 cases. We used IDH1, Ki-67 and Nestin immunomarkers, as well as CDKN2A by FISH. The data were analyzed using SPSS Statistics. The clinical characterization identified only age over 50 years as a risk factor (HR = 3.127). The presence of the tumor residue, as well as the absence of any therapeutic element from the trimodal treatment, were predictive factors of mortality (HR = 1.024, respectively HR = 7.460). Cellular immaturity quantified by Nestin was associated with reduced overall survival (p = 0.007). Increased microvascular density was associated with an increased proliferative index (p = 0.009) as well as alterations of the CDKN2A gene (p < 0.001). CDKN2A deletions and cellular immaturity were associated with an increased percentage of necrosis (p < 0.001, respectively, p = 0.017). The main risk factors involved in the unfavorable prognosis are moderate and increased Nestin immunointensity, as well as the association of increased microvascular density with age over 50 years. Necrosis was not a risk factor.

Role of the TSPO–NOX4 axis in angiogenesis in glioblastoma

Objective: Angiogenesis is a pathological feature of glioblastoma. Nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) is a vital source of reactive oxygen species (ROS) related to angiogenesis. However, signaling pathways correlated with the isoform oxidase are unknown. The aim of this study was to elucidate the detailed mechanism of the role of NOX4 in angiogenesis in glioblastoma.

Methods: Public datasets were searched for studies on immunohistochemistry and western blotting to evaluate NOX4 expression in glioma. The location of NOX4 expression was detected by immunofluorescence. We conducted conditional deletion of the translocator protein (TSPO) targeting the protein with the synthetic ligand XBD173 in the glioblastoma mouse model. NOX4 downregulation was conducted with the NOX4 inhibitor GLX351322, and ROS production and angiogenesis were detected in glioma tissues.

Results: Clinical samples and public datasets showed that NOX4 was upregulated and associated with the prognosis. NOX4 is mainly expressed in endothelial cells of glioblastoma. Both TSPO and NOX4 promoted angiogenesis in an ROS-dependent manner, suggesting that TSPO triggered ROS production in glioblastoma via NOX4.

Conclusion: These results showed that TSPO is an upstream target of NOX4-derived mitochondrial ROS, which is indispensable for NOX4-derived mitochondrial ROS-induced angiogenesis in glioblastoma. TSPO–NOX4 signaling could serve as a molecular target for therapeutic strategies for glioblastoma.

CD34 microvascularity in low-grade glioma: correlation with 5-aminolevulinic acid fluorescence and patient prognosis in a multicenter study at three specialized centers

OBJECTIVE

Early markers are urgently needed in low-grade glioma (LGG) evaluation to rapidly estimate the individual patient's prognosis and to determine the optimal postoperative management. Generally, visible 5-aminolevulinic acid (5-ALA) fluorescence is present in only a few LGGs. Recently, the authors identified visible 5-ALA fluorescence as a powerful intraoperative marker for unfavorable outcome in LGG treatment. However, its precise histopathological correlate is unclear. Neoangiogenesis represents a crucial event in tumor evolution, and CD34 is an established marker for vascular endothelial progenitors potentially indicating tumor progression. The aim of this study was thus to correlate 5-ALA fluorescence and CD34 microvascularity as well as to investigate the prognostic value of CD34 in a large series of LGGs.

METHODS

In this retrospective study including 3 specialized centers, patients with histopathologically confirmed isocitrate dehydrogenase-mutated LGGs (WHO grade II) receiving 5-ALA prior to resection were included. During surgery, the presence of visible fluorescence was analyzed and one representative tumor sample from the area with the maximum fluorescence effect (tumor with focal fluorescence or nonfluorescing tumor) was selected for each LGG. All fluorescing or nonfluorescing tumor samples were stained for CD34 and semiquantitatively analyzed for microvascular proliferation patterns (physiological vessels, branching capillaries, or microvessel clusters) as well as automatically quantified for CD34 microvessel density (MVD) by standardized histomorphometry software. These semiquantitative/quantitative CD34 data were correlated to the fluorescence status and patient outcome including progression-free survival (PFS), malignant transformation-free survival (MTFS), and overall survival (OS).

RESULTS

In a total of 86 LGGs, visible fluorescence was found during surgery in 13 (15%) cases. First, the semiquantitative CD34 score significantly correlated with intraoperative fluorescence (p = 0.049). Accordingly, the quantitative CD34 MVD was significantly higher in tumors showing fluorescence (p = 0.03). Altogether, the semiquantitative CD34 score showed a strong correlation with quantitative CD34 MVD (p < 0.001). At a mean follow-up of 5.4 ± 2.6 years, microvessel clusters in semiquantitative analysis were a prognostic marker for poor PFS (p = 0.01) and MTFS (p = 0.006), but not OS (p = 0.28). Finally, quantitative CD34 MVD > 10 vessels/mm2 was a prognostic marker for poor PFS (p = 0.01), MTFS (p = 0.008), and OS (p = 0.049).

CONCLUSIONS

The data indicate that CD34 microvascularity is associated with intraoperative 5-ALA fluorescence and outcomes in patients with LGG. Thus, visible fluorescence in LGGs might indicate increased CD34 microvascularity, serving as an early prognostic marker for unfavorable patient outcome that is already available during surgery.

Hemodynamic Imaging in Cerebral Diffuse Glioma-Part A: Concept, Differential Diagnosis and Tumor Grading

Diffuse gliomas are the most common primary malignant intracranial neoplasms. Aside from the challenges pertaining to their treatment-glioblastomas, in particular, have a dismal prognosis and are currently incurable-their pre-operative assessment using standard neuroimaging has several drawbacks, including broad differentials diagnosis, imprecise characterization of tumor subtype and definition of its infiltration in the surrounding brain parenchyma for accurate resection planning. As the pathophysiological alterations of tumor tissue are tightly linked to an aberrant vascularization, advanced hemodynamic imaging, in addition to other innovative approaches, has attracted considerable interest as a means to improve diffuse glioma characterization. In the present part A of our two-review series, the fundamental concepts, techniques and parameters of hemodynamic imaging are discussed in conjunction with their potential role in the differential diagnosis and grading of diffuse gliomas. In particular, recent evidence on dynamic susceptibility contrast, dynamic contrast-enhanced and arterial spin labeling magnetic resonance imaging are reviewed together with perfusion-computed tomography. While these techniques have provided encouraging results in terms of their sensitivity and specificity, the limitations deriving from a lack of standardized acquisition and processing have prevented their widespread clinical adoption, with current efforts aimed at overcoming the existing barriers.

Associations between tumor grade, contrast-enhanced ultrasound features, and microvascular density in patients with clear cell renal cell carcinoma: a retrospective study

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) comprises 70% of all renal cell carcinomas (RCCs). Currently, the most important prognostic factor for this type of carcinoma is the World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade. However, nonsurgical methods are rarely used to determine a tumor's WHO/ISUP grade, thus limiting the development of nonsurgical therapies. Due to variations in microvascular density (MVD) at different stages of tumor growth, contrast-enhanced ultrasound (CEUS) features may provide a noninvasive method for evaluating the WHO/ISUP grade of ccRCC.

METHODS

In this study, we analyzed confirmed cases of ccRCC using CEUS features. We also used CD34 and CD31 antibodies to determine MVD. The heterogeneity of CD34 and CD31 expressions were used to determine different degrees of angiogenesis.

RESULTS

When compared to WHO/ISUP grade I/II (G1/G2) tumors, grade III/IV (G3/G4) tumors had reduced peak intensity (PI) (P=0.006), time to peak (TTP) (P<0.001), and relative enhancement percentage index (∆PI%) (P<0.001). However, the frequency of incomplete pseudocapsule (P=0.049) and slow wash-in (P=0.001) was significantly higher in G3/G4 tumors. A cut-off value of ∆PI% <33.15% (P<0.001) allowed identification of G3/G4 tumors with an area under the curve (AUC) of 0.80 [95% confidence interval (CI): 0.70 to 0.91) and a sensitivity of 80%. The mean CD34+ MVD (P<0.001) and CD31+ MVD (P<0.001) were significantly lower in G3/G4 tumors. A positive correlation was revealed between ∆PI% and MVD. There was a statistically significant difference in the density of undifferentiated vessels between the slow wash-in and fast wash-in cases (P<0.001).

CONCLUSIONS

The features of CEUS are effective for differentiating G3/G4 tumors from G1/G2. There was a positive correlation detected between ∆PI% and MVD, and the density of undifferentiated vessels showed a significant difference between slow wash-in and fast wash-in cases. These findings indicate that CEUS can enable the sonographic visualization of tumor angiogenesis and thus be considered an acceptable method for the nonsurgical assessment of tumor microvascular distribution and grade.

Association of the VEGFR2 single nucleotide polymorphism rs2305948 with glioma risk

BACKGROUND

Many studies have reported a relationship between the vascular endothelial growth factor receptor 2 single nucleotide polymorphism (SNP) rs2305948 and glioma, but their conclusions have been controversial. A meta-analysis was performed to assess the association between rs2305948 and glioma susceptibility.

METHODS

Inclusion criteria and a strategy for screening of original literature were created. Eligible articles on the correlation between the SNP rs2305948 and glioma were identified in the PubMed, Embase, Web of Science, Cochrane Library, CNKI and Wanfang databases. After extracting the data, Stata 12. 0 software was used to perform statistical analysis under 5 genetic models and to calculate the combined odds ratio (OR) value and its 95% confidence interval (CI).

RESULTS

Four case-control studies including 1595 cases and 1657 controls were entered into the study. The overall analysis showed that no obvious association existed between rs2305948 and glioma risk (allele: OR = 1.20, 95% CI = 0.93-1.54, P = .162; dominant: OR = 1.17, 95% CI = 0.93-1.46, P = .174; recessive: OR = 1.72, 95% CI = 0.94-3.15, P = .076; heterozygous: OR = 1.11, 95% CI = 0.94-1.30, P = .226; homozygous: OR = 1.74, 95% CI = 0.92-3.29, P = .088). The subgroup analysis suggested that the SNP rs2305948 was related to glioma susceptibility under allele, dominant, recessive and homozygote models in the Asian population (allele: OR = 1.34, 95% CI = 1.16-1.55, P < .001; recessive: OR = 2.24, 95% CI = 1.49-3.36, P < .001; homozygous: OR = 2.32, 95% CI = 1.54-3.50, P < .001).

CONCLUSION

The vascular endothelial growth factor receptor 2 rs2305948 gene polymorphism may be related to glioma susceptibility in the Asian population. However, the association is not clear in non-Asian populations, for which there has been less research.

Proteomic Distributions in CD34+ Microvascular Niche Patterns of Glioblastoma

The poor clinical prognosis and microvascular patterns of glioblastoma (GBM) are of serious concern to many clinicians and researchers. However, very few studies have examined the correlation between microvascular niche patterns (MVNPs) and proteomic distribution. In this study, CD34 immunofluorescence staining and matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-IMS) technology were used to investigate the protein distributions in MVNPs. CD34+ microvascular phenotype could be divided into four types: microvascular sprouting (MS), vascular cluster (VC), vascular garland (VG), and glomeruloid vascular proliferation (GVP). Based on such characteristics, MVNPs were divided into two types by cluster analysis, namely, type I, comprising primarily MS and VC, and type II, comprising many VGs and GVPs. Survival analysis indicated the type of MVNPs to be an independent prognostic factor for progression-free and overall survival in GBM. MALDI-IMS results showed the peaks at m/z 1037 and 8960 to exhibit stronger ion signals in type II, while those at m/z 3240 and 3265 exhibited stronger ion signals in type I. The findings may assist future research on therapy and help predict prognosis in GBM. However, due to the limited number of studies, more well-designed studies are warranted to further verify our results.

The Relationship Between Peritumoral Brain Edema and the Expression of Vascular Endothelial Growth Factor in Vestibular Schwannoma

Objective: This study aimed to explore the potential mechanism of peritumoral brain edema (PTBE) formation in vestibular schwannoma (VS) by detecting intra-tumoral vascular endothelial growth factor (VEGF) expression.

Methods: Between January 2018 and May 2021, 15 patients with PTBE and 25 patients without PTBE were included in the analysis. All patients enrolled in our study underwent surgery in our institution. Expression level of VEGF and microvessel density (MVD) between the two groups were analyzed. Edema index (EI) of each patient with PTBE was calculated.

Results: In the PTBE group, the average of EI was 1.53 ± 0.22. VEGF expression levels were significantly enhanced in the PTBE group compared with the non-PTBE group (p < 0.001). The expression level of VEGF in the PTBE group and non-PTBE group was 1.14 ± 0.21 and 0.52 ± 0.09, respectively. Similarly, there were significantly different amounts of MVD in the two groups (p < 0.001). The amount of MVD in the PTBE group and non-PTBE group was 11.33 ± 1.59 and 6.28 ± 1.77, respectively. Correlation analysis showed a highly significant positive correlation between VEGF and MVD (r = 0.883, p < 0.001) and VEGF and EI (r = 0.876, p < 0.001).

Conclusion: Our study confirmed the close relationship among VEGF expression, tumor angiogenesis, and formation of PTBE in VS patients. It may be possible to develop new effective therapies to attenuate PTBE in VS for alleviation of symptoms and reduction of postoperative complication.

LRIG3 Suppresses Angiogenesis by Regulating the PI3K/AKT/VEGFA Signaling Pathway in Glioma

High levels of microvessel density (MVD) indicate poor prognosis in patients with malignant glioma. Leucine-rich repeats and immunoglobulin-like domains (LRIG) 3, a potential tumor suppressor, plays an important role in tumor progression and may serve as a biomarker in many human cancers. However, its role and underlying mechanism of action in glioma angiogenesis remain unclear. In the present study, we used loss- and gain-of-function assays to show that LRIG3 significantly suppressed glioma-induced angiogenesis, both in vitro and in vivo. Mechanistically, LRIG3 inhibited activation of the PI3K/AKT signaling pathway, downregulating vascular endothelial growth factor A (VEGFA) in glioma cells, thereby inhibiting angiogenesis. Notably, LRIG3 had a significant negative correlation with VEGFA expression in glioma tissues. Taken together, our results suggest that LRIG3 is a novel regulator of glioma angiogenesis and may be a promising option for developing anti-angiogenic therapy.