Frequent B7-H3 overexpression in craniopharyngioma

Targeted treatment for craniopharyngioma

INTRODUCTION

Craniopharyngioma is a rare solid-cystic tumor of the hypothalamopituitary region. Two distinct craniopharyngioma types (formerly subtypes), adamantinomatous and papillary, have been described. These tumors often manifest with neuroendocrine dysfunction, vision problems, hydrocephalus, and cognitive changes. Despite efforts to spare vital brain structures, conventional treatments such as surgery and radiation can exacerbate preceding deficits and contribute to permanent neurologic impairment. Recent studies have identified BRAF-V600E mutations in nearly all papillary craniopharyngiomas (PCP), and CTNNB1/Wnt pathway alterations in adamantinomatous craniopharyngiomas (ACP). These discoveries have advanced our understanding of craniopharyngioma pathogenesis and have opened opportunities for targeted biological treatments.

PURPOSE

The primary objective of this article is to review the current landscape of targeted treatments in papillary and adamantinomatous craniopharyngioma.

RESULTS

Treatment of PCP with BRAF/MEK inhibition has demonstrated durable tumor response in the adjuvant and neoadjuvant settings in multiple case studies and one phase II clinical trial. Although treatment advances are more limited for ACP, CTNNB1/Wnt pathway inhibitors showed promising results in pre-clinical studies and are under continued investigation.

CONCLUSION

The efficacy of BRAF/MEK inhibition in PCP supports the use of targeted therapy in patients with newly diagnosed PCP. The optimal targeted treatment combinations and their timing, duration, long-term effects, and sequencing with traditional therapeutic modalities have not been established and warrant further study. Targeted therapies represent a significant advancement in the field of oncology, and craniopharyngiomas are viable candidates for these approaches pending further research.

The clinical significance of inflammatory mediators in predicting obesity and progression-free survival in patients with adult-onset Craniopharyngioma

BACKGROUND

Craniopharyngioma (CP) is a rare malformational tumor characterized by high rates of recurrence and morbid obesity. However, the role of inflammatory mediators in obesity and the prognosis of patients with CP remains unknown. Therefore, the present study aimed to analyze associations of inflammatory mediators with weight-related outcomes and the prognosis of patients with CP.

METHODS

A total of 130 consecutive patients with CP were included in this study. The expression levels of seven inflammatory mediators and the plasma leptin concentration were investigated. Clinical parameters, weight changes, new-onset obesity, and progression-free survival (PFS) were recorded. The relationships between inflammatory mediators, clinicopathologic parameters, weight-related outcomes, and PFS were explored.

RESULTS

Compared with those in normal pituitary tissue, the expressions of inflammatory mediators in tumor tissue were higher. Higher expression levels of CXCL1 and CXCL8 were identified as independent risk factors for significant weight gain, and CXCL1 and TNF were identified as independent risk factors for new-onset postoperative obesity. Poor PFS was associated with higher expression levels of CXCL1, CXCL8, IL1A, IL6, and TNF.

CONCLUSION

The present study revealed that inflammatory mediators are associated with morbid obesity in patients with CP. Inflammatory mediators may be the critical bridge between elevated leptin and weight-related outcomes. Additionally, PFS was associated with the expression of inflammatory mediators. Further research is needed to elucidate the underlying mechanisms of inflammatory mediators and their potential as targets for novel therapies for CP.

Contemporary Biological Insights and Clinical Management of Craniopharyngioma

Craniopharyngiomas (CPs) are clinically aggressive tumors because of their invasive behavior and recalcitrant tendency to recur after therapy. There are 2 types based on their distinct histology and molecular features: the papillary craniopharyngioma (PCP), which is associated with BRAF-V600E mutations and the adamantinomatous craniopharyngioma (ACP), characterized by mutations in CTNNB1 (encoding β-catenin). Patients with craniopharyngioma show symptoms linked to the location of the tumor close to the optic pathways, hypothalamus, and pituitary gland, such as increased intracranial pressure, endocrine deficiencies, and visual defects. Treatment is not specific and mostly noncurative, and frequently includes surgery, which may achieve gross total or partial resection, followed by radiotherapy. In cystic tumors, frequent drainage is often required and intracystic instillation of drugs has been used to help manage cyst refilling. More recently targeted therapies have been used, particularly in PCP, but also now in ACP and clinical trials are underway or in development. Although patient survival is high, the consequences of the tumor and its treatment can lead to severe comorbidities resulting in poor quality of life, in particular for those patients who bear tumors with hypothalamic involvement. Accordingly, in these patients at risk for the development of a hypothalamic syndrome, hypothalamus-sparing treatment strategies such as limited resection followed by irradiation are recommended. In this review, we provide an update on various aspects of CP, with emphasis on recent advances in the understanding of tumor pathogenesis, clinical consequences, management, and therapies.

Evaluation of B7-H3 Targeted Immunotherapy in a 3D Organoid Model of Craniopharyngioma

A craniopharyngioma (CP) is a rare epithelial tumor of the sellar and parasellar region. CPs are difficult to treat due to their anatomical proximity to critical nervous structures, which limits the ability of the surgeon to completely resect the lesion, exposing patients to a high risk of recurrence. The treatment of craniopharyngiomas is primarily surgery and radiotherapy. So far, neither a cell line nor an animal model has been established, and thus data on other treatment options, such as chemotherapy and immunotherapy, are limited. Here, the expression profile of the pan-cancer antigen B7-H3 in various cancer types including CP was examined by immunohistochemistry. An in vitro organoid model was established by using fresh tissue biospecimens of CP. Based on the organoid model, we evaluated the antitumor efficacy of B7-H3-targeted immunotherapy on CP. As a result, the highest expression of B7-H3 was observed in CP tissues across various cancer types. Although B7-H3-targeted chimeric antigen-receptor T cells show obvious tumor-killing effects in the traditional 2D cell culture model, limited antitumor effects were observed in the 3D organoid model. The B7-H3-targeted antibody-DM1 conjugate exhibited a potent tumor suppression function both in 2D and 3D models. In conclusion, for the first time, we established an organoid model for CP and our results support that B7-H3 might serve as a promising target for antibody-drug conjugate therapy against craniopharyngioma.

To kill a cancer: Targeting the immune inhibitory checkpoint molecule, B7-H3

Targeting the anti-tumor immune response via the B7 family of immune-regulatory checkpoint proteins has revolutionized cancer treatment and resulted in punctuated responses in patients. B7-H3 has gained recent attention given its prominent deregulation and immunomodulatory role in a multitude of cancers. Numerous cancer studies have firmly established a strong link between deregulated B7-H3 expression and poorer outcomes. B7-H3 has been shown to augment cancer cell survival, proliferation, metastasis, and drug resistance by inducing an immune evasive phenotype through its effects on tumor-infiltrating immune cells, cancer cells, cancer-associated vasculature, and the stroma. Given the complex interplay between each of these components of the tumor microenvironment, a deeper understanding of B7-H3 signaling properties is inherently crucial to developing efficacious therapies that can target and inhibit these cancer-promoting interactions. This review delves into the various ways B7-H3 acts as an immunomodulator to facilitate immune evasion and promote tumor growth and spread. With post-transcriptional and post-translational modifications giving rise to different active isoforms coupled with recent discoveries of its putative receptors, B7-H3 can perform diverse functions. Here, we first discuss the dual co-stimulatory/co-inhibitory functions of B7-H3 in the context of normal physiology and cancer. We then discuss the crosstalk facilitated by B7-H3 between stromal components and tumor cells that promote tumor growth and metastasis in different populations of tumor cells, associated vasculature, and the stroma. Concurrently, we highlight therapeutic strategies that can exploit these interactions and their associated limitations, concluding with a special focus on the promise of next-gen in silico-based approaches to small molecule inhibitor drug discovery for B7-H3 that may mitigate these limitations.

B7-H3-targeted CAR-T cell therapy for solid tumors

Since B7-H3 is overexpressed or amplified in many types of solid tumors with a restricted expression in the normal tissues, it has been an emerging immunotherapeutic target for solid tumors. This review will focus on the structural designs of developing chimeric antigen receptors (CARs) targeting B7-H3. The expression, receptor, and function of the B7-H3, as well as a short overview of B7-H3-targeted monoclonal antibody therapy, are discussed. Finally, a detailed summary of B7-H3 redirected CAR-T and CAR-NK cell approaches utilized in preclinical models and currently ongoing or completed clinical trials are presented. It has been demonstrated that B7-H3-targeted CAR-based cell therapies were safe in initial trials, but their efficacy was limited. Employing the local delivery routes, the introduction of novel modifications promoting CAR-T persistence, and combined treatment with other standard therapies could improve the efficacy of B7-H3-targeted CAR-T cell therapy against solid tumors.

Current Advances in the Management of Adult Craniopharyngiomas

Craniopharyngiomas (CPs) are slow growing, histologically benign intracranial tumors located in the sellar–suprasellar region. Although known to have low mortality, their location and relationship to the adjacent neural structures results in patients having significant neurologic, endocrine, and visual comorbidities. The invasive nature of this tumor makes complete resection a challenge and contributes to its recurrence. Additionally, these tumors are bimodally distributed, being treated with surgery, and are followed by other adjuncts, such as focused radiation therapy, e.g., Gamma knife. Advances in surgical techniques, imaging tools, and instrumentations have resulted in the evolution of surgery using endoscopic techniques, with residual components being treated by radiotherapy to target the residual tumor. Advances in molecular biology have elucidated the main pathways involved in tumor development and recurrence, but presently, no other treatments are offered to patients, besides surgery, radiation, and endocrine management, as the disease and tumor evolve. We review the contemporary management of these tumors, from the evolution of surgical treatments, utilizing standard open microscopic approaches to the more recent endoscopic surgery, and discuss the current recommendations for care of these patients. We discuss the developments in radiation therapy, such as radiosurgery, being used as treatment strategies for craniopharyngioma, highlighting their beneficial effects on tumor resections while decreasing the rates of adverse outcomes. We also outline the recent chemotherapy modalities, which help control tumor growth, and the immune landscape on craniopharyngiomas that allow the development of novel immunotherapies.

Evaluation of the role of soluble B7-H3 in association with membrane B7-H3 expression in gastric adenocarcinoma

BACKGROUND AND OBJECTIVE

Gastric adenocarcinoma (GAC) is one of the most common malignancies. Increasing data have indicated a correlation between soluble B7-H3 (sB7-H3) levels and tumor malignancies. In this study, we aim to investigate the level of soluble B7-H3 in serum of GAC patients. Further, we analyze the correlation between sB7-H3 level and tissue B7-H3 expression and explore the clinical evaluation value of sB7-H3 associated with pathological characteristics and prognosis of GAC patients.

METHODS

One hundred and twenty-eight serum and tissue samples of GAC 20 serum and tissue samples of gastritis patients and 77 serum, 5 tissue samples of healthy controls were collected. The serum levels of sB7-H3 were detected by Enzyme-linked immunosorbent assay (ELISA), while the expression of membrane B7-H3 (mB7-H3) and Ki67 were evaluated by immunohistochemistry. The correlation between sB7-H3 and mB7-H3, sB7-H3 and Ki67, sB7-H3 or mB7-H3 and clinical features were analyzed by Pearson's Chi-square test.

RESULTS

Both serum level of sB7-H3 and tissue B7-H3 of GAC patients were significantly higher than those of gastritis patients and healthy controls. sB7-H3 level was correlated with total B7-H3 expression in tissues (r= 0.2801, P= 0.0014). Notably, the concentration of sB7-H3 was correlated with its expression of membrane form in tumor cells (r= 0.3251, P= 0.002) while not in stromal cells (r= 0.07676, P= 0.3891). Moreover, the levels of sB7-H3 in patients with TNM stage III/IV or with Infiltration depth T3/T4 or with lymph node metastasis were significantly higher than those of patients with TNM stage I/II (P= 0.0020) or with Infiltration depth T1/T2 (P= 0.0169) or with no lymph node metastasis (P= 0.0086). Tumor B7-H3 score, but not stromal B7-H3 score, in patients with TNM stage III/IV or with lymph node metastasis was significantly higher than those with TNM stage I/II (P= 0.0150) or with no lymph node metastasis (P= 0.182).

CONCLUSIONS

Soluble B7-H3 level may reflect the tissue B7-H3 expression on tumor cells of GAC tissues. Elevated level of sB7-H3 in serum suggests poor clinical pathological characteristics of GAC patients.

Advances in immunotherapeutic targets for childhood cancers: A focus on glypican-2 and B7-H3

Cancer immunotherapies have revolutionized how we can treat adult malignancies and are being translated to pediatric oncology. Chimeric antigen receptor T-cell therapy and bispecific antibodies targeting CD19 have shown success for the treatment of pediatric patients with B-cell acute lymphoblastic leukemia. Anti-GD2 monoclonal antibody has demonstrated efficacy in neuroblastoma. In this review, we summarize the immunotherapeutic agents that have been approved for treating childhood cancers and provide an updated review of molecules expressed by pediatric cancers that are under study or are emerging candidates for future immunotherapies. Advances in our knowledge of tumor immunology and in genome profiling of cancers has led to the identification of new tumor-specific/associated antigens. While cell surface antigens are normally targeted in a major histocompatibility complex (MHC)-independent manner using antibody-based therapies, intracellular antigens are normally targeted with MHC-dependent T cell therapies. Glypican 2 (GPC2) and B7-H3 (CD276) are two cell surface antigens that are expressed by a variety of pediatric tumors such as neuroblastoma and potentially can have a positive impact on the treatment of pediatric cancers in the clinic.

Overcoming Challenges for CD3-Bispecific Antibody Therapy in Solid Tumors

Immunotherapy of cancer with CD3-bispecific antibodies is an approved therapeutic option for some hematological malignancies and is under clinical investigation for solid cancers. However, the treatment of solid tumors faces more pronounced hurdles, such as increased on-target off-tumor toxicities, sparse T-cell infiltration and impaired T-cell quality due to the presence of an immunosuppressive tumor microenvironment, which affect the safety and limit efficacy of CD3-bispecific antibody therapy. In this review, we provide a brief status update of the CD3-bispecific antibody therapy field and identify intrinsic hurdles in solid cancers. Furthermore, we describe potential combinatorial approaches to overcome these challenges in order to generate selective and more effective responses.

Expression and clinical significance of PD-L1, B7-H3, B7-H4 and VISTA in craniopharyngioma

Background

Craniopharyngioma (CP) is a common refractory tumor of the central nervous system. However, little is known about the expression and clinical significance of B7 family ligands/receptors in CP patients. Thus, we conducted the present study to address this issue in a cohort of 132 CP cases.

Methods

We mapped and quantified the expression of B7 family ligands/receptors molecules programmed cell death ligand 1 (PD-L1), B7-H3, B7-H4 and V-domain Ig-containing suppressor of T cell activation (VISTA) in 89 adamantinomatous-type CP and 43 papillary-type CP samples using immunohistochemistry and immunofluorescence. Associations between the marker levels, clinicopathological variables and survival were evaluated.

Results

The positive rates of PD-L1, B7-H3, B7-H4 and VISTA in the cohort of 132 CP cases were 76.5%, 100%, 40.2% and 80.3%, respectively. The cut-off values of PD-L1, B7-H3, B7-H4 and PD-L1 expression were determined by survival receiver operating characteristic (ROC) package, which was 70, 182, 0 and 20, respectively. Elevated expressions of PD-L1, B7-H3, B7-H4 and VISTA were significantly associated with some clinicopathological characteristics. Kaplan-Meier analysis indicated that higher VISTA expressions correlated with better overall survival (OS) and progression-free survival (PFS) (p=0.0053 and p=0.0066, respectively). Multivariate Cox regression analysis indicated that VISTA was an independent prognostic factor for OS (p=0.018) but not for PFS (p=0.898).

Conclusions

We found variable expression of PD-L1, B7-H3, B7-H4 and VISTA proteins in CPs. The results suggest that the expression level of VISTA may be used as an important indicator to predict the OS and PFS of CPs. B7 family ligands/receptors could be potential immunotherapeutic targets when treating CPs.

News on immune checkpoint inhibitors as immunotherapy strategies in adult and pediatric solid tumors

Immune checkpoint inhibitors (ICIs) have shown unprecedented benefits in various adult cancers, and this success has prompted the exploration of ICI therapy even in childhood malignances. Although the use of ICIs as individual agents has achieved disappointing response rates, combinational therapies are likely to promise better results. However, only a subset of patients experienced prolonged clinical effects, thus suggesting the need to identify robust bio-markers that predict individual clinical response or resistance to ICI therapy as the main challenge. In this review, we focus on how the use of ICIs in adult cancers can be translated into pediatric malignances. We discuss the physiological mechanism of action of each IC, including PD-1, PD-L1 and CTLA-4 and the new emerging ones, LAG-3, TIM-3, TIGIT, B7-H3, BTLA and IDO-1, and evaluate their prognostic value in both adult and childhood tumors. Furthermore, we offer an overview of preclinical models and clinical trials currently under investigation to improve the effectiveness of cancer immunotherapies in these patients. Finally, we outline the main predictive factors that influence the efficacy of ICIs, in order to lay the basis for the development of a pan-cancer immunogenomic model, able to direct young patients towards more specific immunotherapy.