The alteration of Id-1 and TSP-1 expression in mucoepidermoid carcinoma associated with its clinical features and prognosis

Phase 1 dose expansion and biomarker study assessing first-in-class tumor microenvironment modulator VT1021 in patients with advanced solid tumors

BACKGROUND

Preclinical studies have demonstrated that VT1021, a first-in-class therapeutic agent, inhibits tumor growth via stimulation of thrombospondin-1 (TSP-1) and reprograms the tumor microenvironment. We recently reported data from the dose escalation part of a phase I study of VT1021 in solid tumors. Here, we report findings from the dose expansion phase of the same study.

METHODS

We analyzed the safety and tolerability, clinical response, and biomarker profile of VT1021 in the expansion portion of the phase I study (NCT03364400). Safety/tolerability is determined by adverse events related to the treatment. Clinical response is determined by RECIST v1.1 and iRECIST. Biomarkers are measured by multiplexed ion beam imaging and enzyme-linked immunoassay (ELISA).

RESULTS

First, we report the safety and tolerability data as the primary outcome of this study. Adverse events (AE) suspected to be related to the study treatment (RTEAEs) are mostly grade 1-2. There are no grade 4 or 5 adverse events. VT1021 is safe and well tolerated in patients with solid tumors in this study. We report clinical responses as a secondary efficacy outcome. VT1021 demonstrates promising single-agent clinical activity in recurrent GBM (rGBM) in this study. Among 22 patients with rGBM, the overall disease control rate (DCR) is 45% (95% confidence interval, 0.24-0.67). Finally, we report the exploratory outcomes of this study. We show the clinical confirmation of TSP-1 induction and TME remodeling by VT1021. Our biomarker analysis identifies several plasmatic cytokines as potential biomarkers for future clinical studies.

CONCLUSIONS

VT1021 is safe and well-tolerated in patients with solid tumors in a phase I expansion study. VT1021 has advanced to a phase II/III clinical study in glioblastoma (NCT03970447).

Role of TSP-1 as prognostic marker in various cancers: a systematic review and meta-analysis

Background

Published studies present conflicting data regarding the impact of Thrombospondin-1 (TSP-1) expression on prognosis of various cancers. We performed this meta-analysis to illustrate the preliminary predictive value of TSP-1.

Methods

Twenty-four studies with a total of 2379 patients were included. A comprehensive literature search was performed by using PubMed, Cochrane Library, Web of Science, Embase, and hand searches were also conducted of relevant bibliographies. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) for patient survival and disease recurrence were initially identified to explore relationships between TSP-1 expression and patient prognosis.

Results

A total of 24 eligible studies were included in this meta-analysis. Our results showed that high level of TSP-1 was correlated significantly with poor overall survival (OS) (HR = 1.40, 95% CI: 1.17 ~ 1.68; P<0.001). However, high TSP-1 expression predicted no significant impact on progression-free survival (PFS)/ metastasis-free survival (MFS) (HR = 1.35, 95%CI: 0.87–2.10; P = 0.176) and disease-free survival (DFS)/ recurrence-free survival (RFS) (HR = 1.40, 95%CI: 0.77–2.53; P = 0.271). In addition, we performed subgroup analyses which showed that high TSP-1 expression predicted poor prognosis in breast cancer and gynecological cancer. Additionally, the relatively small number of studies on PFS/MFS and DFS/RFS is a limitation. The data extracted through Kaplan-Meier curves may not be accurate. Moreover, only English articles were included in this article, which may lead to deviations in the results.

Conclusions

Our findings indicated high TSP-1 expression may act as a promising biomarker of poor prognosis in cancers, especially in breast cancer and gynecological cancer.

[Relationship between thrombospondin-1 and the occurrence and development of oral and maxillofacial malignancy]

Thrombospondin-1 (TSP-1) is widely distributed in human tissues and is important in inhibiting angiogenesis.It also occupies an indispensable position in the formation, growth, differentiation, and metastasis of tumors in different tissues.TSP-1 plays an important role in the occurrence and development of various types of tumors. The inhibitory effect of TSP-1 on the angiogenesis and tumor development of oral and maxillofacial malignant tumors has been demonstrated in recent years. This paper reviews the findings and progress of TSP-1 research involving all kinds of tumors as well as oral and maxillofacial malignancies.

Microencapsulation of low-passage poorly-differentiated human mucoepidermoid carcinoma cells by alginate microcapsules: in vitro profiling of angiogenesis-related molecules

Background

Human mucoepidermoid carcinoma (MEC) is regarded as the most common primary salivary malignancy. High-grade MEC has a high risk of recurrence and poor prognosis. Tumor angiogenesis, induced by poorly differentiated cancer cells of high-grade MEC, contributes to tumor growth and metastasis. Therefore, elucidating molecular mechanisms underlying the pro-angiogenic ability of poorly differentiated MEC cells is critical for the understanding of high-grade MEC progression. It is well known that three-dimensional (3D) cell culture, in contrast with conventional two-dimensional (2D) culture, provides a better approach to in vitro recapitulation of in vivo characteristics of cancer cells and their surrounding microenvironment. The purpose of this study was to model a 3D environment for in vitro gene expression profiling of key molecules in poorly differentiated MEC cells for cancer neovascularization and compared them with traditional 2D cell culture.

Methods

Low-passage poorly differentiated MEC cells, derived from human patient samples of high-grade MEC, were microencapsulated in sodium alginate gel microcapsules (3D culture) and compared with cells grown in 2D culture. Cancer cell proliferation was determined by MTT assays for 1 week, and gene expression of VEGF-A, bFGF and TSP-1 was analyzed by western blotting or ELISA. The hypoxic environment in 3D versus 2D culture were assessed by western blotting or immunofluorescence for HIF1α, and the effect of hypoxia on VEGF-A gene expression in 3D cultured cancer cells was assessed by western blotting with the use of the HIF1α inhibitor, 2-methoxyestradiol (2-MeOE2).

Results

When encapsulated in alginate gel microcapsules, low-passage poorly differentiated human MEC cells grew in blocks and demonstrated stronger and relatively unlimited proliferation activities. Moreover, significant differences were found in gene expression, with 3D-grown cancer cells a significant increment of VEGF-A and bFGF and a drastic reduction of TSP-1. Consistently, 3D-grown cancer cells secreted significantly more VEGF-A than 2D culture cancer cells. Furthermore, 3D-grown cancer cells showed significantly higher expression of HIF1α, a molecular indicator of hypoxia; the increased expression of VEGF-A in 3D cultured cancer cells was shown to be dependent on the HIF1α activities.

Conclusions

The present work shows the effects of 3D culture model by alginate microencapsulation on the proangiogenic potentials of low-passage poorly differentiated human MEC cells. Cancer cells in this 3D system demonstrate significant intensification of key molecular processes for tumor angiogenesis. This is due to a better modeling of the hypoxic tumor microenvironment during 3D culture.

TGF-β1-induced expression of Id-1 is associated with tumor progression in gastric cancer

Transforming growth factor β1 (TGF-β1) and inhibitor of differentiation/DNA-binding 1 (Id-1) have been shown to be associated with aggressive metastatic behavior of cancer cells in many malignant tumors. However, their role in gastric cancer (GC) has not been established. In this study, we investigated the relationship between expression of Id-1 and TGF-β1 in GC as well as their association with GC progression. The immunohistochemical analysis of 71 human GC samples indicated that both Id-1 and TGF-β1 were markedly upregulated in tumor tissue compared with the adjacent tissue; in addition, a significant positive correlation was found between the expression levels of Id-1 and TGF-β1 by Pearson's correlation analysis. Furthermore, the investigation of the association of Id-1 and TGF-β1 with patient clinical characteristics revealed that Id-1 expression was significantly correlated with tumor differentiation, while TGF-β1 was associated with lymph node metastasis. The results were validated in vitro by using a GC cell line, AGS. The expression of Id-1 was upregulated at 24 and 48 h after the treatment with TGF-β1, whereas it did not affect the proliferation of cells. TGF-β1 also influenced the expression of N-cadherin and β-catenin. Our results suggested that Id-1 and TGF-β1 played important roles in the progression of GC, in which Id-1 might act as a downstream mediator of TGF-β1 signaling through a regulatory mechanism involving N-cadherin and β-catenin. The TGF-β1/Id-1 axis might serve as a future therapeutic target for GC.