Meningiomas and Somatostatin Analogs: A Systematic Scoping Review on Current Insights and Future Perspectives

Diarylpentanoid, a curcumin analog, inhibits malignant meningioma growth in both in vitro and in vivo models

BACKGROUND

Malignant meningioma metastasizes systemically, primarily due to its role in epithelial-mesenchymal transition. Although the prognosis is extremely poor, drug development efforts have been limited, because this tumor is categorized as a rare form.

AIM

To examine growth suppressive effect of GO-Y030, a diarylpentanoid curcumin analog, (1E,4E)-1,5-bis [3,5-bis (methoxymethoxy) phenyl] penta-1,4-dien-3-one against the malignant meningioma.

METHODS

The growth suppression of malignant meningioma cells by GO-Y022 and GO-Y030 were examined, using IOMM-Lee and HKBMM cell lines. Male nude mice aged eight weeks, specifically BALB/cSlc-nu/nu mice received a subcutaneous inoculation of IOMM-Lee (10⁷ cells/site) on their back and 30 μg/kg of recombinant hepatocellular growth factor (HGF) was injected into the tumor every three days. After confirmed the growth tumor mass, 500 μL of GO-Y030 diluted with PBS were administrated intraperitoneally daily at doses of 1 mg/kg and 2 mg/kg, respectively.

RESULTS

GO-Y030 exhibits a growth inhibitory effect on malignant meningioma cell lines, IOMM-Lee and HKBMM ranging from 0.8-2.0 μM in vitro. Notably, GO-Y030’s inhibitory effect is about 10 to 16^th times more potent than that of curcumin, which has previously demonstrated potential in combating malignant meningioma. In mouse models, the intraperitoneal administration of GO-Y030 effectively suppresses the growth of malignant meningioma tumors that have been inoculated in the back (P = 0.002). High-performance liquid chromatography analysis has confirmed the distribution of GO-Y030 in the bloodstream and brain tissue. Moreover, GO-Y030 demonstrates the ability to significantly suppress HGF (P < 0.01), nuclear factor kappa B (P < 0.001), and N-cadherin (P < 0.001), all of which contribute to the epithelial-mesenchymal transition.

CONCLUSION

GO-Y030 holds promise as a potent compound for the systemic inhibition of malignant meningioma. GO-Y030 has higher tumor growth inhibitory effect against meningiomas than curcumin, which is known to have antitumor activity through multi-molecular target control resulting in apoptosis induction. GO-Y030 controls at least three molecules of HGF, nuclear factor kappa B, and N-cadherin.

Functional precision medicine assay for recurrent meningioma: a proof of principle. Illustrative case

BACKGROUND

Meningiomas are the most prevalent primary central nervous system tumors. Although low-grade meningiomas are considered benign tumors, a subset of these can behave aggressively, showing progression and recurrence. In such cases, functional assays could influence treatment decisions and improve patient outcomes.

OBSERVATIONS

A 78-year-old female presented with a long-standing history of a supratentorial meningioma that was initially resected and treated with Gamma Knife radiosurgery. Surveillance revealed progression. She began systemic therapy with everolimus and octreotide but was lost to follow-up and did not continue the treatment. She returned because of a rapid decline in her neurological status. Biopsy with advanced molecular characterization by next-generation sequencing revealed NF2 and CREBBP mutations, and a commercial functional assay was done. This assay successfully isolated cancer stem cells (CSCs) from biopsy cores and identified potential drugs based on cellular sensitivity profiles. This is the first reported case in which a commercial functional drug screen was used for a meningioma.

LESSONS

In cases in which meningiomas exhibit specific genetic alterations and characteristics of aggressiveness, functional assays can be a useful tool for isolating CSCs. The authors report success in obtaining drug-screen profiling for a World Health Organization grade 1 meningioma. Multimodal approaches utilizing multi-omics analyses with functional assays can improve patient outcomes. https://thejns.org/doi/10.3171/CASE24242.

Cytotoxicity on low-grade canine meningioma with the use of somatostatin analog (octreotide): An in vitro study

Background

Meningioma is the most common tumor of the central nervous system of dogs. For this tumor, surgery remains the treatment of choice, either alone or in combination with radiotherapy. Unfortunately, chemotherapeutic strategies are practically absent in dogs and palliative therapies are the only option to surgery. Somatostatin receptor subtype 2 (SSTR2) is expressed in canine meningioma. Since the potent cell-proliferation inhibiting effect of somatostatin (SST), the aim of this study was to investigate in vitro the effects of octreotide, as SST analog, in the viability of canine meningioma.

Methods

Four surgical canine meningiomas were used in this study to establish cell cultures. Expression of SSTR2 was verified with immunolabelling in FFPE samples and cell cultures. The effects of octreotide on cell viability were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT). After 24 hours they were exposed to different concentrations of octreotide (0.1 nM, 1 nM, 10 nM, 100 nM) for 24 and 48 hours.

Results

All meningiomas consisted of grade I tumors. The cultured neoplastic cells expressed SSTR2 from 80% to 100%. Octreotide significantly increased cell death after 48 hours of continuous exposure, with 10 and 100 nM octreotide doses. The percentage of cell viability was 80.92 ± 4.9 and 80.49 ± 3.61, compared to the control, respectively, consistent with decreased cell viability of about 20% for both doses.

Conclusions

Octreotide reduced the alive neoplastic cultured cells of low-grade canine meningioma in a dose-dependent pattern with continuous exposition for 48 hours. These results support an alternative systemic treatment of meningioma with octreotide in the dog.

The Role of Receptor-Ligand Interaction in Somatostatin Signaling Pathways: Implications for Neuroendocrine Tumors

Neuroendocrine tumors (NETs) arise from neuroendocrine cells and manifest in diverse organs. Key players in their regulation are somatostatin and its receptors (SSTR1-SSTR5). Understanding receptor-ligand interactions and signaling pathways is vital for elucidating their role in tumor development and therapeutic potential. This review highlights SSTR characteristics, localization, and expression in tissues, impacting physiological functions. Mechanisms of somatostatin and synthetic analogue binding to SSTRs, their selectivity, and their affinity were analyzed. Upon activation, somatostatin initiates intricate intracellular signaling, involving cAMP, PLC, and MAP kinases and influencing growth, differentiation, survival, and hormone secretion in NETs. This review explores SSTR expression in different tumor types, examining receptor activation effects on cancer cells. SSTRs' significance as therapeutic targets is discussed. Additionally, somatostatin and analogues' role in hormone secretion regulation, tumor growth, and survival is emphasized, presenting relevant therapeutic examples. In conclusion, this review advances the knowledge of receptor-ligand interactions and signaling pathways in somatostatin receptors, with potential for improved neuroendocrine tumor treatments.