Functional Role of Matrix gla Protein in Glioma Cell Migration

Vitamins and dietary supplements in cancer treatment: is there a need for increased usage?

INTRODUCTION

Vitamins are essential for homeostasis and proper functioning of organisms. These micronutrients prevent tumor onset by functioning as antioxidants and enzymatic cofactors involved in anti-stress and immune responses, modulating epigenetic regulators, and shaping the microbiota composition. Unbalanced diets and sedentary lifestyles contribute to obesity, associated with increasing cancer risk. Cancer patients often exhibit vitamin deficiencies due to chronic inflammation, anticancer therapies, and tumor-induced metabolic changes, leading to malnutrition and cachexia.

AREAS COVERED

This review critically analyzes preclinical and clinical studies, sourced from PubMed and ClinicalTrials.gov databases, that investigate the potential benefits of vitamin supplementation and dietary interventions, such as intermittent fasting and ketogenic diets, in mouse tumor models and cancer patients. This analysis elucidates the limitations of such interventions and suggests optimal dietary strategies to prevent cancer and enhance patients' quality of life and prognosis.

EXPERT OPINION

To date, clinical studies have found no substantial benefit of over-the-counter vitamin supplements and dietary interventions on cancer patients' health and prognosis. To prevent the spread of useless and potentially harmful products by the nutraceutical industry, establishing a regulatory authority is necessary to monitor and ensure product quality and validity before commercialization.

New insights into vitamin K biology with relevance to cancer

Phylloquinone (vitamin K1) and menaquinones (vitamin K2 family) are essential for post-translational γ-carboxylation of a small number of proteins, including clotting factors. These modified proteins have now been implicated in diverse physiological and pathological processes including cancer. Vitamin K intake has been inversely associated with cancer incidence and mortality in observational studies. Newly discovered functions of vitamin K in cancer cells include activation of the steroid and xenobiotic receptor (SXR) and regulation of oxidative stress, apoptosis, and autophagy. We provide an update of vitamin K biology, non-canonical mechanisms of vitamin K actions, the potential functions of vitamin K-dependent proteins in cancer, and observational trials on vitamin K intake and cancer.

The Nuclear Function of IL-33 in Desensitization to DNA Damaging Agent and Change of Glioma Nuclear Structure

Glioma, the most common subtype of primary brain tumor, is an aggressive and highly invasive neurologically tumor among human cancers. Interleukin-33 (IL-33) is considered as a dual functional cytokine, an alarmin upon tissue damage and a nuclear chromatin-associated protein. Despite that, IL-33 is known to foster the formation of the inflammatory tumor microenvironment and facilitate glioma progression, evidence showing nuclear IL-33 function is still poor. In this study using lentivirus-mediated IL-33 gene knockdown (IL33KD) and IL-33 overexpression (IL33oe) in rat C6 glioma cells and human glioma cell lines (U251MG and U87MG), we found that IL33oe-glioma cells had resistance to the insults of the alkylating agent, temozolomide (TMZ), possibly because of the increased expression of DNA repair genes (i.e., BRCA1, BRCA2, Rad51, FANCB, and FANCD) in IL33oe-glioma cells. Alternatively, examination of glioma nuclear shape from transmission electron microscopy (TEM) imaging analysis and immunofluorescence for histone protein H2A staining showed that IL33KD attenuated the abnormal cancerous nuclear characteristic, such as indentation, long clefts, and multiple nucleoids. Yet, IL33oe promoted the changes in glioma nuclear shapes, such as the formation of multiple lobes. We further found that histone proteins, H2A and H3, were reduced in IL33KD glioma cells. The non-histone DNA-binding nucleoproteins, the high mobility group A1 (HMGA1) and HMGA2, were also downregulated by IL33KD. In contrast, IL33oe increased H2A and H3 proteins and HMGA1 and HMGA2 in glioma cells. Altogether, the upregulation of nuclear IL-33 expression was along with an increase in the expression of DNA repair genes, contributing to the desensitization of glioma cells to DNA damaging agents. Moreover, nuclear IL-33 proteins in cooperation with chromatin-associated proteins regulate glioma nuclear structure, which might be crucial for glioma progression and malignancy.

SLC39A7 promotes malignant behaviors in glioma via the TNF-α-mediated NF-κB signaling pathway

Purpose: Several studies have indicated that SLC39A7 plays an important role in tumor progression; however, little is known about the function and mechanism of SLC39A7 in glioma. In this study, we aimed to explore the role of SLC39A7 in glioma development. Patients and methods: Bioinformatic analysis was used to predict the role of SLC39A7 in glioma. Cell viability and Edu assays were used to detect the proliferation of glioma cells. A transwell assay was used to measure the invasion and migration of glioma cells. Western blotting, qPCR and ELISA were used to detect the expression of all molecules. Results: SLC39A7 was found to be highly expressed in high-grade glioma patients with a poor prognosis. Our results indicated that SLC39A7 significantly promoted the proliferation, invasion and migration of glioma cells. Furthermore, SLC39A7 promoted tumorigenesis in orthotopic models. We determined that SLC39A7 promotes the malignant behaviors of glioma by activating the TNF-α-mediated NF-κB signaling pathway. Conclusion: Our study revealed that SLC39A7 promotes the proliferation, invasion and migration of glioma cells via the TNF-α-mediated NF-κB signaling pathway, which provides potential targets for glioma therapy.

Unique cartilage matrix-associated protein inhibits the migratory and invasive potential of triple-negative breast cancer

Triple-negative breast cancer (TNBC) that lacks expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) is a breast cancer subtype with very aggressive metastasis and poor prognosis. Unique cartilage matrix-associated protein (UCMA) is a vitamin K-dependent protein (VKDP) with a high-density γ-carboxyglutamic acid (Gla) domain due to the action of vitamin K. UCMA promotes osteoblast differentiation and mineral deposition in bone and suppresses calcification in vessels. However, correlation between UCMA and TNBC is unknown. This study investigated the inhibitory effect of UCMA on TNBC cell in vitro migration, invasion, and colony formation in addition to in vivo tumorigenesis. Cell migration and invasion significantly decreased in Ucma-overexpressing MDA-MB-231 and 4T1 cells compared to the mock control cells. Also, colony formation and the number of colonies significantly decreased in Ucma-overexpressing MDA-MB-231 and 4T1 cells. These results indicate that UCMA significantly inhibits the migration, invasion, and colony formation of TNBC cells. In an in vivo xenograft mouse model, tumor growth significantly decreased in mice bearing Ucma-overexpressing TNBC cells compared to the mock control cells, indicating that UCMA reduced in vivo tumor growth, similar to the inhibitory role of UCMA in vitro. Survival analysis using publicly available database showed that high UCMA expression significantly correlated with favorable relapse-free survival in TNBC patients compared to those with the other VKDPs, matrix Gla protein (MGP) and osteocalcin (OCN). Collectively, this study suggests that UCMA is a promising new therapeutic agent for TNBC.

Silencing of tumor-suppressive NR_023387 in renal cell carcinoma via promoter hypermethylation and HNF4A deficiency

Dysregulation of the epigenetic status of long noncoding RNAs (lncRNAs) has been linked to diverse human diseases including human cancers. However, the landscape of the whole-genome methylation profile of lncRNAs and the precise roles of these lncRNAs remain elusive in renal cell carcinoma (RCC). We first examined lncRNA expression profiles in RCC tissues and corresponding adjacent normal tissues (NTs) to identify the lncRNA signature of RCC, then lncRNA Promoter Microarray was performed to depict the whole-genome methylation profile of lncRNAs in RCC. Combined analysis of the lncRNAs expression profiles and lncRNAs Promoter Microarray identified a series of downregulated lncRNAs with hypermethylated promoter regions, including NR_023387. Quantitative real-time polymerase chain reaction (RT-PCR) implied that NR_023387 was significantly downregulated in RCC tissues and cell lines, and lower expression of NR_023387 was correlated with shorter overall survival. Methylation-specific PCR, MassARRAY, and demethylation drug treatment indicated that hypermethylation in the NR_023387 promoter contributed to its silencing in RCC. Besides, HNF4A regulated the expression of NR_023387 via transcriptional activation. Functional experiments demonstrated NR_023387 exerted tumor-suppressive roles in RCC via suppressing the proliferation, migration, invasion, tumor growth, and metastasis of RCC. Furthermore, we identified MGP as a putative downstream molecule of NR_023387, which promoted the epithelial-mesenchymal transition of RCC cells. Our study provides the first whole-genome lncRNA methylation profile in RCC. Our combined analysis identifies a tumor-suppressive and prognosis-related lncRNA NR_023387, which is silenced in RCC via promoter hypermethylation and HNF4A deficiency, and may exert its tumor-suppressive roles by downregulating the oncogenic MGP.

Evaluation of MGP gene expression in colorectal cancer

PURPOSE

Matrix Gla protein (MGP) is a vitamin K-dependent, γ-carboxylated protein that was initially found to be a physiological inhibitor of ectopic calcifications affecting mainly cartilage and the vascular system. Mutations in the MGP gene were found to be responsible for a human pathology, the Keutel syndrome, characterized by abnormal calcifications in cartilage, lungs, brain and vascular system. MGP was recently implicated in tumorigenic processes such as angiogenesis and shown to be abnormally regulated in several tumors, including cervical, ovarian, urogenital and breast. This fact has triggered our interest in analyzing the expression of MGP and of its regulator, the transcription factor runt related transcription factor 2 (RUNX2), in colorectal cancer (CRC).

METHODS

MGP and RUNX2 expression were analyzed in cancer and non-tumor biopsies samples from 33 CRC patients and 9 healthy controls by RT-qPCR. Consequently, statistical analyses were performed to evaluate the clinical-pathological significance of MGP and RUNX2 in CRC. MGP protein was also detected by immunohistochemical analysis.

RESULTS

Showed an overall overexpression of MGP in the tumor mucosa of patients at mRNA level when compared to adjacent normal mucosa and healthy control tissues. In addition, analysis of the expression of RUNX2 mRNA demonstrated an overexpression in CRC tissue samples and a positive correlation with MGP expression (Pearson correlation coefficient 0.636; p ≤ 0.01) in tumor mucosa. However correlations between MGP gene expression and clinical-pathological characteristics, such as gender, age and pathology classification did not provide relevant information that may shed light towards the differences of MGP expression observed between normal and malignant tissue.

CONCLUSIONS

We were able to associate the high levels of MGP mRNA expression with a worse prognosis and survival rate lower than five years. These results contributed to improve our understanding of the molecular mechanism underlying MGP deregulation in cancer.

RUNX1 contributes to the mesenchymal subtype of glioblastoma in a TGFβ pathway-dependent manner

Runt-Related Transcription Factor 1 (RUNX1) is highly expressed in the Mesenchymal (Mes) subtype of glioblastoma (GBM). However, the specific molecular mechanism of RUNX1 in Mes GBM remains largely elusive. In this study, cell and tumor tissue typing were performed by RNA-sequencing. Co-immunoprecipitation (co-IP) and immunofluorescence (IF) were employed to identify members of the RUNX1 transcriptional protein complex. Bioinformatics analysis, chromatin immunoprecipitation (ChIP), and luciferase reporter experiments were utilized to verify target genes. Analyses of The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) verified the expression levels and prognoses associated with RUNX1/p-SMAD3/SUV39H1 target genes. In vivo patient-derived xenograft (PDX) studies and in vitro functional studies verified the impact of RUNX1 on the occurrence and development of GBM. The results showed that RUNX1 was upregulated in Mes GBM cell lines, tissues and patients and promoted proliferation and invasion in GBM in a TGFβ pathway-dependent manner in vivo and in vitro. We found and verified that BCL3 and MGP are transcriptionally activated by p-SMAD3 /RUNX1, while MXI1 is transcriptionally suppressed by the RUNX1/SUV39H1-H3K9me3 axis. This finding offers a theoretical rationale for using molecular markers and choosing therapeutic targets for the Mes type of GBM.

Prosaposin promotes the proliferation and tumorigenesis of glioma through toll-like receptor 4 (TLR4)-mediated NF-κB signaling pathway

Background

As a neurotrophic factor, prosaposin (PSAP) can exert neuroprotective and neurotrophic effects. It is involved in the occurrence and development of prostate and breast cancer. However, there is no research about the role of PSAP in glioma.

Methods

The PSAP overexpressed or silenced glioma cells or glioma stem cells were established based on Lentiviral vector transfection. Cell viability assay, Edu assay, neurosphere formation assay and xenograft experiments were used to detect the proliferative ability. Western blot, Elisa and luciferase reporter assays were used to detect the possible mechanism.

Findings

Our study firstly found that PSAP was highly expressed and secreted in clinical glioma specimens, glioma stem cells, and glioma cell lines. It was associated with poor prognosis. We found that PSAP significantly promoted the proliferation of glioma stem cells and cell lines. Moreover, PSAP promoted tumorigenesis in subcutaneous and orthotopic models of this disease. Furthermore, GSEA and KEGG analysis predicted that PSAP acts through the TLR4 and NF-κB signaling pathways, which was confirmed by western blot, immunoprecipitation, immunofluorescence, and use of the TLR4-specific inhibitor TAK-242.

Interpretation

The findings of this study suggest that PSAP can promote glioma cell proliferation via the TLR4/NF-κB signaling pathway and may be an important target for glioma treatment.

Fund

This work was funded by National Natural Science Foundation of China (Nos. 81101917, 81270036, 81201802, 81673025), Program for Liaoning Excellent Talents in University (No. LR2014023), and Liaoning Province Natural Science Foundation (Nos. 20170541022, 20172250290). The funders did not play a role in manuscript design, data collection, data analysis, interpretation nor writing of the manuscript.

The Role of Matrix Gla Protein (MGP) Expression in Paclitaxel and Topotecan Resistant Ovarian Cancer Cell Lines

The major cause of ovarian cancer treatment failure in cancer patients is inherent or acquired during treatment drug resistance of cancer. Matrix Gla protein (MGP) is a secreted, non-collagenous extracellular matrix protein involved in inhibition of tissue calcification. Recently, MGP expression was related to cellular differentiation and tumor progression. A detailed MGP expression analysis in sensitive (A2780) and resistant to paclitaxel (PAC) (A2780PR) and topotecan (TOP) (A2780TR) ovarian cancer cell lines and their corresponding media was performed. MGP mRNA level (real time PCR analysis) and protein expression in cell lysates and cell culture medium (Western blot analysis) and protein expression in cancer cells (immunofluorescence analysis) and cancer patient lesions (immunohistochemistry) were determined in this study. We observed increased expression of MGP in PAC and TOP resistant cell lines at both mRNA and protein level. MGP protein was also detected in the corresponding culture media. Finally, we detected expression of MGP protein in ovarian cancer lesions from different histological type of cancer. MGP is an important factor that might contribute to cancer resistance mechanism by augmenting the interaction of cells with ECM components leading to increased resistance of ovarian cancer cells to paclitaxel and topotecan. Expression found in ovarian cancer tissue suggests its possible role in ovarian cancer pathogenesis.