Association of cavernous malformation within vestibular schwannoma: immunohistochemical analysis of matrix metalloproteinase-2 and -9

Polymorphisms in genes related to oxidative stress and inflammation: Emerging links with the pathogenesis and severity of Cerebral Cavernous Malformation disease

Cerebral Cavernous Malformation (CCM) is a cerebrovascular disease of genetic origin affecting 0.5% of the population and characterized by abnormally enlarged and leaky capillaries that predispose to seizures, neurological deficits, and intracerebral hemorrhage (ICH). CCM occurs sporadically or is inherited as dominant condition with incomplete penetrance and highly variable expressivity. Three disease genes have been identified: KRIT1 (CCM1), CCM2 and CCM3. Previous results demonstrated that loss-of-function mutations of CCM genes cause pleiotropic effects, including defective autophagy, altered reactive oxygen species (ROS) homeostasis, and enhanced sensitivity to oxidative stress and inflammatory events, suggesting a novel unifying pathogenetic mechanism, and raising the possibility that CCM disease onset and severity are influenced by the presence of susceptibility and modifier genes. Consistently, genome-wide association studies (GWAS) in large and homogeneous cohorts of patients sharing the familial form of CCM disease and identical mutations in CCM genes have led to the discovery of distinct genetic modifiers of major disease severity phenotypes, such as development of numerous and large CCM lesions, and susceptibility to ICH. This review deals with the identification of genetic modifiers with a significant impact on inter-individual variability in CCM disease onset and severity, including highly polymorphic genes involved in oxidative stress, inflammatory and immune responses, such as cytochrome P450 monooxygenases (CYP), matrix metalloproteinases (MMP), and Toll-like receptors (TLR), pointing to their emerging prognostic value, and opening up new perspectives for risk stratification and personalized medicine strategies.

Unexpected Binding of Tozuleristide "Tumor Paint" to Cerebral Vascular Malformations: A Potentially Novel Application of Fluorescence-Guided Surgery

BACKGROUND

Fluorescence-guided surgery (FGS) is under investigation as a means to improve the extent of resection for primary central nervous system (CNS) tumors. Tozuleristide, known also as "Tumor Paint," is an investigational tumor-targeting agent covalently conjugated to a derivative of the fluorescent dye indocyanine green.

OBJECTIVE

To report the finding of avid intraoperative fluorescence of tozuleristide on cerebral vascular malformations.

METHODS

Our institution is participating in a phase 2/3 study of intraoperative near-infrared fluorescence detection of pediatric primary CNS tumors in patients receiving intravenous tozuleristide and imaged with the Canvas system. Our site enrolled 2 patients with intracranial lesions, suspected preoperatively of possibly being gliomas that proved to be cavernous vascular malformations after resection.

RESULTS

Each lesion had a dark blue mulberry appearance and each fluoresced avidly with tozuleristide. Each was completely resected, and the patients recovered without deficit. Pathological assessment showed cavernous angioma for both cases. Tozuleristide fluorescence is postulated to result from binding to matrix metalloproteinase-2 and annexin A2, and literature review demonstrates expression of both these ligands on multiple cerebrovascular lesions, including cavernous malformations.

CONCLUSION

This finding deserves further investigation to determine if tozuleristide "Tumor Paint" may have a wider role in the identification of non-neoplastic intracranial pathologies.

A Novel Role of Cab45-G in Mediating Cell Migration in Cancer Cells

Ca²⁺-binding protein of 45 kDa (Cab45), a CREC family member, is reported to be associated with Ca²⁺-dependent secretory pathways and involved in multiple diseases including cancers. Cab45-G, a Cab45 isoform protein, plays an important role in protein sorting and secretion at Golgi complex. However, its role in cancer cell migration remains elusive. In this study, we demonstrate that Cab45-G exhibited an increased expression in cell lines with higher metastatic potential and promoted cell migration in multiple types of cancer cells. Overexpression of Cab45-G resulted in an altered expression of the molecular mediators of epithelial-mesenchymal transition (EMT), which is a critical step in the tumor metastasis. Quantitative real-time PCR showed that overexpression of Cab45-G increased the expression of matrix metalloproteinase-2 and -7 (MMP-2 and MMP-7). Conversely, knock-down of Cab45-G reduced the expression of the above MMPs. Moreover, forced expression of Cab45-G upregulated the level of phosphorylated ERK and modulated the secretion of extracellular proteins fibronectin and fibulin. Furthermore, in human cervical and esophageal cancer tissues, the expression of Cab45-G was found to be significantly correlated with that of MMP-2, further supporting the importance of Cab45-G on regulating cancer metastasis. Taken together, these results suggest that Cab45-G could regulate cancer cell migration through various molecular mechanisms, which may serve as a therapeutic target for the treatment of cancers.

Expression and significance of MMP2 and HIF-1α in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a serious threat to human health. HCC is a malignant tumor and its invasion and metastasis are the result of multigene interactions. Matrix metalloproteinase-2 (MMP-2) is capable of degrading the majority of components of the extracellular matrix and is regarded to closely correlate with tumor invasion and metastasis. Furthermore, the hypoxia-inducible factor 1α (HIF-1α) is an important transcription factor, which is closely associated with the process of tumor growth. The aim of the present study was to investigate the expression of MMP2 and HIF-1α) in HCC, and the relationship between MMP2/HIF-1α protein expression and the clinical/pathological characteristics of HCC. The mRNA levels of MMP2 and HIF-1α were detected in 32 cases of HCC and the corresponding normal adjacent tissues with fluorescence-based quantitative polymerase chain reaction (qPCR). The protein expression of MMP2 and HIF-1α was assessed in 45 HCC cases and 33 cases of corresponding normal adjacent tissue, using immunohistochemical methods. The association between MMP2/HIF-1α and pathological features of HCC, and the correlation between MMP2 and HIF-1α were analyzed. The Kaplan-Meier method was used to assess the impact of MMP2 and HIF-1α expression on survival. The fluorescence-based qPCR demonstrated that MMP2 and HIF-1α mRNA expression levels in the HCC tissues were 0.84±0.17 and 0.87±0.11, respectively, which were significantly higher than those in the adjacent normal tissues (0.70±0.13 and 0.68±0.13, respectively; P<0.05). Immunohistochemical analysis revealed that MMP2 and HIF-1α protein expression in the HCC tissues was 63.1 and 70.8%, respectively, which was also higher than that in the adjacent normal tissues (34.2 and 36.8%, respectively). There was no significant correlation between the expression of MMP2 or HIF-1α protein and the age or gender of patients with HCC (P>0.05). However, there was significant correlation between MMP2 or HIF-1α protein expression and tumor size, metastasis, presence of a capsule and clinical TNM staging of HCC. Their expression also had a significant effect on patient survival time. In conclusion, MMP2 and HIF-1α are overexpressed in HCC, and the MMP2 signaling pathway may promote the development of HCC together with HIF-1α.

Development of intratumoral cyst or extratumoral arachnoid cyst in intracranial schwannomas following gamma knife radiosurgery

PURPOSE

Intracranial schwannomas presenting with cyst formation following gamma knife radiosurgery (GKRS) were investigated to clarify their clinicopathological characteristics.

METHODS

Between 1994 and 2006, 492 patients presenting with intracranial schwannomas underwent GKRS. Among them, seven cases demonstrated either new formation of cysts or enlargement of preexisting cysts, which were treated with microsurgical intervention. These cases were retrospectively reviewed with regard to neuroradiological findings and histopathology.

RESULTS

These seven cases included five vestibular and two trigeminal schwannomas. Preexisting cysts were enlarged following GKRS in three cases, while they were newly formed in four cases. Salvage microsurgery was carried out at 7-167 months after the GKRS, and subtotal resection was achieved in three, partial resection with or without cyst fenestration in four. Neurological symptoms were improved in all six symptomatic cases. Preoperative MRI demonstrated two characteristic types of cyst. One was the intratumoral type, indicating hemorrhagic change on the MRI. Histopathological analysis demonstrated a cavernous angioma within the solid compartment of tumor. These two cases demonstrated enlargement of residual tumor with new cyst formation after resection of only the cyst. The other type was extratumoral cyst, which had a structure with a thin cyst wall without contrast enhancement, and the cyst was composed of arachnoid cells without tumor cells. Extratumoral cysts enlarged despite effective control of the tumor itself, which may be caused by osmotic gradient induced by tumor degeneration following GKRS.

CONCLUSIONS

There were two types of cysts, intratumoral cyst and extratumoral arachnoid cyst, which developed following GKRS in intracranial schwannomas. Resection of the solid compartment as well as the cyst is required in schwannomas with expanding intratumoral cyst. Conversely, fenestration of the cyst alone might be effective in extratumoral arachnoid cysts.

De novo formation of orbital cavernous malformation 9 years after surgical management of dural arteriovenous fistula in the anterior middle fossa: case report

A 30-year-old man presented with recurrent dural arteriovenous fistula (dAVF) associated with de novo orbital cavernous malformation (CM), manifesting as progressive left visual disturbance. He had undergone transarterial embolization and subsequent surgical management for a left anterior middle fossa dAVF 9 years previously. External carotid angiography showed recurrence of the dAVF. Magnetic resonance imaging revealed a well delineated intraorbital mass lesion with hypointense signal rim by T(2)-weighted imaging, adjacent to the shunting point of the recurrent dAVF. Transcranial subtotal removal of the intraorbital mass lesion through the orbitopterional approach revealed continuity between the mass lesion and the draining vein of the recurrent dAVF. The histological diagnosis was CM. His symptom was relieved postoperatively, and no regrowth was seen during the follow-up period of one year. The coexistence of recurrent dAVF with newly formed orbital CM is extremely rare, but may indicate the underlying mechanism of the formation of CMs and recurrent dAVF.

Abnormal blood vessels formed by human liver cavernous hemangioma endothelial cells in nude mice are suitable for drug evaluation

Cavernous hemangioma is vascular malformation with developmental aberrations. It was assumed that the abnormality of endothelial cells contributed greatly to the occurrence of cavernous hemangioma. In our previous study, we have found distinct characteristics of endothelial cells derived from human liver cavernous hemangioma (HCHEC). Here, we reported the abnormal vascular vessels formed by primary HCHEC in nude mice and that the drug podophyllotoxin can destroy HCHEC in vitro and in vivo. HCHEC was isolated from a human liver cavernous hemangioma specimen, and the HCHEC generated a red hemangioma-like mass 7 days after subcutaneously co-inoculating HCHEC and human liver cancer cells (Bel-7402) in nude mice. Lentiviral expression of GFP and immunohistochemistry for human CD31 was used to confirm that the HCHEC formed the blood vessels in nude mice. And the pathological features of vascular vessels formed by HCHEC were very similar to clinical cavernous hemangioma. In addition, by MTT assay, the drug podophyllotoxin was found inhibiting HCHEC viability, and by TUNEL and DNA ladder assays, podophyllotoxin was found inducing apoptosis of HCHEC. Moreover, podophyllotoxin was also effective for destroying the abnormal vascular vessels in the hemangioma-like mass in nude mice. In summary, the HCHEC can form abnormal blood vessels in nude mice, and we can evaluate drugs for cavernous hemangioma by using HCHEC in vitro and in vivo.