The intracellular form of human MAGP1 elicits a complex and specific transcriptional response

Immunosuppressive MFAP2+ cancer associated fibroblasts conferred unfavorable prognosis and therapeutic resistance in gastric cancer

PURPOSE

To explore the predictive merit of MFAP2+ cancer associated fibroblasts (CAFs) infiltration for clinical outcomes and adjuvant chemotherapy or immunotherapy responsiveness in gastric cancer (GC).

METHODS

In this study, several independent cohorts were included respectively to dissect the relationship of clinical outcomes, therapeutic responses and tumor microenvironment with different MFAP2+ CAFs infiltration. Drug sensitivity analysis was conducted to predict the relationship between MFAP2+ CAFs infiltration and targeted drug response. Kaplan-Meier curves and the log-rank test were used to compare clinical outcomes of patients with different MFAP2+ CAFs infiltration.

RESULTS

High MFAP2+ CAFs infiltration yielded inferior prognosis in terms of overall survival, progress free survival and recurrence free survival in GC. Patients with low MFAP2+ CAFs infiltration were more likely to gain benefit from adjuvant therapy. Moreover, low MFAP2+ CAFs infiltration could predict a promising response to immunotherapy in GC patients. MFAP2+ CAFs with immunosuppressive features were highly relevant to immune evasive contexture characterized by the dysfunction of CD8+ T cells. We found that MFAP2+ CAFs communicated with T cells, B cells and Macrophages through releasing macrophage migration inhibitor factor (MIF), which further suggested that MFAP2+ CAFs might promote therapeutic resistance through regulating T cells dysfunction and M2 macrophages polarization.

CONCLUSION

Immunosuppressive MFAP2+ CAFs constructed an immune evasive tumor microenvironment characterized by incapacitated immune effector cells, consequently predicting inferior clinical outcomes and response on adjuvant therapy and immunotherapy in patients with GC. The potential of immunosuppressive MFAP2+ CAFs as a therapeutic target for GC deserved thoroughly exploration.

Identification and Validation of a m5C RNA Modification-Related Gene Signature for Predicting Prognosis and Immunotherapeutic Efficiency of Gastric Cancer

Background

5-methylcytosine (m5C) is a major site of RNA methylation modification, and its abnormal modification is associated with the development of gastric cancer (GC). This study aimed to explore the value of m5C-related genes on the prognosis of GC patients through bioinformatics.

Methods

First, m5C-related genes were obtained by nonnegative matrix factorization (NMF) analysis and differentially expressed analysis. The m5C-related model was established and validated in distinct datasets. Moreover, a differential analysis of risk scores according to clinical characteristics was performed. The enrichment analysis was carried out to elucidate the underlying molecular mechanisms. Furthermore, we calculated the differences in immunotherapy and chemotherapy sensitivity between the high- and low-risk groups. Finally, we validated the expression levels of identified model genes by quantitative real-time polymerase chain reaction (qRT-PCR).

Results

A total of five m5C-related subtypes of GC patients in the TCGA database were identified. The m5C-related model was constructed based on APOD, ASCL2, MFAP2, and CREB3L3. Functional enrichment revealed that the m5C-related model might involve in the cell cycle and cell adhesion. Moreover, the high-risk group had a higher abundance of stromal and immune cells in malignant tumor tissues and a lower tumor purity than the low-risk group. The patients in the high-risk group were more sensitive to chemotherapy and had better sensitivity to CTLA4 inhibitors. Furthermore, qRT-PCR results from our specimens verified an over-expression of ASCL2, CREB3L3, and MFAP2 in the cancer cells compared with the normal cells.

Conclusion

A total of five GC subtypes were identified, and a risk model was constructed based on m5C modification.

The role of microfibrillar‐associated protein 2 in cancer

Microfibrillar-associated protein 2 (MFAP2), a component of the extracellular matrix, is important in controlling growth factor signal transduction. Recent studies have shown that MFAP2, an effective prognostic molecule for various tumors, is associated with tumor occurrence and development and may be involved in remodeling the extracellular matrix and regulating proliferation, apoptosis, invasion, tumor cell metastasis, and tumor angiogenesis. However, MFAP2’s specific mechanism in these tumor processes remains unclear. This article reviewed the possible mechanism of MFAP2 in tumorigenesis and progression and provided a reference for the clinical prognosis of patients with cancer and new therapeutic target discovery.

Upregulation of microfibrillar-associated protein 2 is closely associated with tumor angiogenesis and poor prognosis in hepatocellular carcinoma

Abnormal expression of microfibrillar-associated protein 2 (MFAP2), a key regulator of cellular differentiation, affects the occurrence and progression of tumors. However, the underlying role of MAFP2 in hepatocellular carcinoma (HCC) remains unclear. In the present study, patterns of MFAP2 expression in HCC were analyzed using sequencing data from The Cancer Genome Atlas database. Expression profiles of MFAP2, as well as those of epithelial-mesenchymal transition (EMT)-related proteins, were compared between HCC pathological sections and fresh tissues. Thereafter, associations between patterns of MFAP2 expression and the clinicopathological characteristics of patients, and identified risk factors associated with disease-free survival (DFS) and overall survival (OS), were determined. The functions of MFAP2 in the EMT-induced proliferation and migration of MHCC97H cells were investigated using in vitro experiments, and the effects of MFAP2 on vascular endothelial growth factor A (VEGFA)-induced tumor angiogenesis were also investigated. Upregulation of MFAP2 expression was observed in HCC, and was often accompanied by the abnormal expression of EMT-related marker proteins. In addition, analysis of clinical data from 94 patients with tumor tissues revealed a significant positive correlation between MFAP2 expression and low DFS and low OS following surgery. Through in vitro experimentation, silencing MFAP2 expression was shown inhibit EMT, which thereby inhibited cellular proliferation and migration. Moreover, downregulation of MFAP2 inhibited tumor angiogenesis via the inhibition of VEGFA. Taken together, these findings indicate that MFAP2 has the potential to predict the prognosis of patients with HCC. MFAP2 also induces tumor cell proliferation and migration through EMT, and promotes tumor blood vessel formation through VEGFA, suggesting that MFAP2 may be a potential therapeutic target for HCC.

MFAP2 Promotes the Proliferation of Cancer Cells and Is Associated With a Poor Prognosis in Hepatocellular Carcinoma

Backgrounds:

Microfibril-associated protein 2 (MFAP2) is an extracellular matrix protein that regulates the function of microfibrils by interacting with fibrillin. MFAP2 has been reported to play an important role in metabolic diseases and has been shown to be significantly overexpressed in head and neck squamous cell carcinoma and Hepatocellular carcinoma (HCC). However, the molecular function and prognostic value of MFAP2 have never been reported in HCC or other tumors.

Methods:

In the present study, expression characteristics of MFAP2 in HCC, its influence on the development of HCC, as well as its function and potential mechanism in HCC were verified by Quantitative reverse transcription-polymerase chain reaction, bioinformatics data mining and in vitro cell experiments.

Results:

MFAP2 was prominently high-expressed in HCC and associated with cancer stages. HCC patients with higher MFAP2 expression displayed lower overall survival (OS) and disease-specific survival(DSS), while there was no significant difference in recurrence-free survival (RFS). In vitro experiments showed that downregulation of MFAP2 inhibited proliferation, migration level of HCC cells. Transcription factors, DNA methyltransferases, immune factors may interact with MFAP2 mRNA to promote tumor progression in HCC.

Conclusion:

These findings suggest that MFAP2 may play a key role in the development of HCC. Therefore, MFAP2 may be a valuable prognostic marker and an effective anticancer target in HCC.

MFAP2 is overexpressed in gastric cancer and promotes motility via the MFAP2/integrin α5β1/FAK/ERK pathway

Gastric cancer (GC) is one of the most common malignancies and its prognosis is extremely poor. This study identifies a novel oncogene, microfibrillar-associated protein 2 (MFAP2) in GC. With integrative reanalysis of transcriptomic data, we found MFAP2 as a GC prognosis-related gene. And the aberrant expression of MFAP2 was explored in GC samples. Subsequent experiments indicated that silencing and exogenous MFAP2 could affect motility of cancer cells. The inhibition of silencing MFAP2 could be rescued by another FAK activator, fibronectin. This process is probably through affecting the activation of focal adhesion process via modulating ITGB1 and ITGA5. MFAP2 regulated integrin expression through ERK1/2 activation. Silencing MFAP2 by shRNA inhibited tumorigenicity and metastasis in nude mice. We also revealed that MFAP2 is a novel target of microRNA-29, and miR-29/MFAP2/integrin α5β1/FAK/ERK1/2 could be an important oncogenic pathway in GC progression. In conclusion, our data identified MFAP2 as a novel oncogene in GC and revealed that miR-29/MFAP2/integrin α5β1/FAK/ERK1/2 could be an important oncogenic pathway in GC progression.

Integrated analysis of microfibrillar-associated proteins reveals MFAP4 as a novel biomarker in human cancers

Aim: The potential functions and underlying mechanism of microfibrillar-associated proteins (MFAPs) are explored in human cancers. Materials & methods: Here, we examined the expression profiles, prognostic values, epigenetic and genetic alterations of MFAPs in human cancers from public omics repository. Results: Among MFAPs family, MFAP4 was frequently downregulated in the most human cancers and high mRNA expression of MFAP4 significantly correlated with better overall survival in breast cancer. DNA hypermethylation in the promoter of MFAP4 decreased its mRNA expression. MFAP4 strongly associated with pathway in impairment and alteration of the elastic fibers. Conclusion: This integrated analysis provides new insights into MFAPs in human cancers and indicates that MFAP4 could be used as novel biomarker for developing therapies against human cancers.

The microfibril-associated glycoproteins (MAGPs) and the microfibrillar niche

The microfibril-associated glycoproteins MAGP-1 and MAGP-2 are extracellular matrix proteins that interact with fibrillin to influence microfibril function. The two proteins are related through a 60 amino acid matrix-binding domain but their sequences differ outside of this region. A distinguishing feature of both proteins is their ability to interact with TGFβ family growth factors, Notch and Notch ligands, and multiple elastic fiber proteins. MAGP-2 can also interact with αvβ3 integrins via a RGD sequence that is not found in MAGP-1. Morpholino knockdown of MAGP-1 expression in zebrafish resulted in abnormal vessel wall architecture and altered vascular network formation. In the mouse, MAGP-1 deficiency had little effect on elastic fibers in blood vessels and lung but resulted in numerous unexpected phenotypes including bone abnormalities, hematopoietic changes, increased fat deposition, diabetes, impaired wound repair, and a bleeding diathesis. Inactivation of the gene for MAGP-2 in mice produced a neutropenia yet had minimal effects on bone or adipose homeostasis. Double knockouts had phenotypes characteristic of each individual knockout as well as several additional traits only seen when both genes are inactivated. A common mechanism underlying all of the traits associated with the knockout phenotypes is altered TGFβ signaling. This review summarizes our current understanding of the function of the MAGPs and discusses ideas related to their role in growth factor regulation.

Elastic fibres in health and disease

Elastic fibres are insoluble components of the extracellular matrix of dynamic connective tissues such as skin, arteries, lungs and ligaments. They are laid down during development, and comprise a cross-linked elastin core within a template of fibrillin-based microfibrils. Their function is to endow tissues with the property of elastic recoil, and they also regulate the bioavailability of transforming growth factor β. Severe heritable elastic fibre diseases are caused by mutations in elastic fibre components; for example, mutations in elastin cause supravalvular aortic stenosis and autosomal dominant cutis laxa, mutations in fibrillin-1 cause Marfan syndrome and Weill–Marchesani syndrome, and mutations in fibulins-4 and -5 cause autosomal recessive cutis laxa. Acquired elastic fibre defects include dermal elastosis, whereas inflammatory damage to fibres contributes to pathologies such as pulmonary emphysema and vascular disease. This review outlines the latest understanding of the composition and assembly of elastic fibres, and describes elastic fibre diseases and current therapeutic approaches.

Oophorectomy-induced bone loss is attenuated in MAGP1-deficient mice

Microfibril-associated glycoprotein-1 (MAGP1), together with the fibrillins, are constitutive components of vertebrate microfibrils. Mice deficient in MAGP1 (murine MAGP1 knockout animals (Mfap2(-/-)); MAGP1Δ) is appropriate develop progressive osteopenia and reduced whole bone strength, and have elevated numbers of osteoclasts lining the bone surface. Our previous studies suggested that the increased osteoclast population was associated with elevated levels of receptor activator of NF-κB ligand (RANKL), a positive regulator of osteoclast differentiation. To explore the relationship between RANKL expression and osteoclast differentiation in MAGP1 deficiency, oophorectomy (OVX) was used to stimulate RANKL expression in both WT and MAGP1Δ animals. Bone loss following OVX was monitored using whole body DEXA and in vivo µCT. While WT mice exhibited significant bone loss following OVX, percent bone loss was reduced in MAGP1Δ mice. Further, serum RANKL levels rose significantly in OVX WT mice, whereas, there was only a modest increase in RANKL following OVX in the mutant mice due to already high baseline levels. Elevated RANKL expression was normalized when cultured MAGP1Δ osteoblasts were treated with a neutralizing antibody targeting free TGFβ. These studies provide support for increased RANKL expression associated with MAGP1 deficiency and provide a link to altered TGF-β signaling as a possible causative signaling pathway regulating RANKL expression in MAGP1Δ osteoblasts.

Deficiency in microfibril-associated glycoprotein-1 leads to complex phenotypes in multiple organ systems

Microfibril-associated glycoprotein-1 (MAGP-1) is a small molecular weight component of the fibrillin-rich microfibril. Gene-targeted inactivation of MAGP-1 reveals a complex phenotype that includes increased body weight and size due to excess body fat, an altered wound healing response in bone and skin, and a bleeding diathesis. Elastic tissues rich in MAGP-1-containing microfibrils develop normally and show normal function. The penetrance of MAGP-1-null phenotypes is highly variable and mouse strain-dependent, suggesting the influence of modifier genes. MAGP-1 was found to bind active transforming growth factor-beta (TGF-beta) and BMP-7 with high affinity, suggesting that it may be an important modulator of microfibril-mediated growth factor signaling. Many of the phenotypic traits observed in MAGP-1-deficient mice are consistent with loss of TGF-beta function and are generally opposite those associated with mutations in fibrillin-1 that result in enhanced TGF-beta signaling. Increased body size and fat deposition in MAGP-1-mutant animals are particularly intriguing given the localization of obesity traits in humans to the region on chromosome 1 containing the MAGP-1 gene.