MSX2 in pancreatic tumor development and its clinical application for the diagnosis of pancreatic ductal adenocarcinoma

The benign nature and rare occurrence of cardiac myxoma as a possible consequence of the limited cardiac proliferative/ regenerative potential: a systematic review

BACKGROUND

Cardiac Myxoma is a primary tumor of heart. Its origins, rarity of the occurrence of primary cardiac tumors and how it may be related to limited cardiac regenerative potential, are not yet entirely known. This study investigates the key cardiac genes/ transcription factors (TFs) and signaling pathways to understand these important questions.

METHODS

Databases including PubMed, MEDLINE, and Google Scholar were searched for published articles without any date restrictions, involving cardiac myxoma, cardiac genes/TFs/signaling pathways and their roles in cardiogenesis, proliferation, differentiation, key interactions and tumorigenesis, with focus on cardiomyocytes.

RESULTS

The cardiac genetic landscape is governed by a very tight control between proliferation and differentiation-related genes/TFs/pathways. Cardiac myxoma originates possibly as a consequence of dysregulations in the gene expression of differentiation regulators including Tbx5, GATA4, HAND1/2, MYOCD, HOPX, BMPs. Such dysregulations switch the expression of cardiomyocytes into progenitor-like state in cardiac myxoma development by dysregulating Isl1, Baf60 complex, Wnt, FGF, Notch, Mef2c and others. The Nkx2-5 and MSX2 contribute predominantly to both proliferation and differentiation of Cardiac Progenitor Cells (CPCs), may possibly serve roles based on the microenvironment and the direction of cell circuitry in cardiac tumorigenesis. The Nkx2-5 in cardiac myxoma may serve to limit progression of tumorigenesis as it has massive control over the proliferation of CPCs. The cardiac cell type-specific genetic programming plays governing role in controlling the tumorigenesis and regenerative potential.

CONCLUSION

The cardiomyocytes have very limited proliferative and regenerative potential. They survive for long periods of time and tightly maintain the gene expression of differentiation genes such as Tbx5, GATA4 that interact with tumor suppressors (TS) and exert TS like effect. The total effect such gene expression exerts is responsible for the rare occurrence and benign nature of primary cardiac tumors. This prevents the progression of tumorigenesis. But this also limits the regenerative and proliferative potential of cardiomyocytes. Cardiac Myxoma develops as a consequence of dysregulations in these key genes which revert the cells towards progenitor-like state, hallmark of CM. The CM development in carney complex also signifies the role of TS in cardiac cells.

MSX2 safeguards syncytiotrophoblast fate of human trophoblast stem cells

Multiple placental pathologies are associated with failures in trophoblast differentiation, yet the underlying transcriptional regulation is poorly understood. Here, we discovered msh homeobox 2 (MSX2) as a key transcriptional regulator of trophoblast identity using the human trophoblast stem cell model. Depletion of MSX2 resulted in activation of the syncytiotrophoblast transcriptional program, while forced expression of MSX2 blocked it. We demonstrated that a large proportion of the affected genes were directly bound and regulated by MSX2 and identified components of the SWItch/Sucrose nonfermentable (SWI/SNF) complex as strong MSX2 interactors and target gene cobinders. MSX2 cooperated specifically with the SWI/SNF canonical BAF (cBAF) subcomplex and cooccupied, together with H3K27ac, a number of differentiation genes. Increased H3K27ac and cBAF occupancy upon MSX2 depletion imply that MSX2 prevents premature syncytiotrophoblast differentiation. Our findings established MSX2 as a repressor of the syncytiotrophoblast lineage and demonstrated its pivotal role in cell fate decisions that govern human placental development and disease.

A six-gene-based prognostic model predicts complete remission and overall survival in childhood acute myeloid leukemia

Objective

Acute myeloid leukemia (AML) is a malignant clonal disorder. Despite enormous progress in its diagnosis and treatment, the mortality rate of AML remains high. The aim of this study was to identify prognostic biomarkers by using the gene expression profile dataset from public database, and to improve the risk-stratification criteria of survival for patients with AML.

Materials and methods

The gene expression data and clinical parameter were acquired from the Therapeutically Applicable Research to Generate Effective Treatment (TARGET) database. A total of 856 differentially expressed genes (DEGs) were obtained from the childhood AML patients classified into first complete remission (CR1) group (n=791) and not CR group (n=249). We performed a series of bioinformatics analysis to screen key genes and pathways, further comprehending these DEGs through Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses.

Results

Six genes (SLC17A7, MSX2, CDC26, MSLN, CTSZ and DEFA3) identified by univariate, Kaplan-Meier survival and multivariate Cox regression analyses were used to develop the prognostic model. Further analysis showed that the survival estimations in the high-risk group had an increased risk of death compared with the low-risk group based on the model. The area under the curve of the receiver operator characteristic curve in the prognostic model for predicting the overall survival was 0.729, confirming good prognostic model. We also performed a nomogram to provide an individual patient with the overall probability, and internal validation in the TARGET cohort.

Conclusion

We identified a six-gene prognostic signature for risk-stratifying in patients with childhood AML. The risk classification model can be used to predict CR markers and may assist clinicians in providing realize the individualized treatment in this patient population.

Prognostic Relevance and Function of MSX2 in Colorectal Cancer

Colorectal cancer patients with diabetes had the high risks of total mortality. High expression of MSX2 is related to development of diabetes. There are few reports about the clinical implications and function of MSX2 in colorectal cancer (CRC). The purpose of this study is to investigate the relationship between the expression of MSX2 and clinical relevance and discover the possible mechanism of MSX2 in the development of CRC. Compared with adjacent tissues, the expression of MSX2 was higher in tumor tissues in both mRNA and protein levels (P < 0.01). Kaplan-Meier survival analysis showed that high mRNA expression of MSX2 was associated with short survival time (P = 0.013). Chi-squared test analysis indicated that MSX2 expression was related to tumor size (P = 0.04), tumor locus (P = 0.025), clinical stage (P < 0.001), tumor invasion (P = 0.003), lymphatic metastasis (P = 0.01), and distant metastasis (P = 0.033). In vitro experiments demonstrated that knockdown of MSX2 expression attenuated cell proliferation and invasion, promoted cell cycle arrest and apoptosis, and inactivated Akt phosphorylation. In conclusion, MSX2 played a crucial role in the progression of CRC and may be a potential novel prognostic factor and therapeutic target for CRC therapy. Our work may provide certain enlightenment for investigating the mechanism of MSX2 in the process of diabetes.

MSX2 Induces Trophoblast Invasion in Human Placenta

Normal implantation depends on appropriate trophoblast growth and invasion. Inadequate trophoblast invasion results in pregnancy-related disorders, such as early miscarriage and pre-eclampsia, which are dangerous to both the mother and fetus. Msh Homeobox 2 (MSX2), a member of the MSX family of homeobox proteins, plays a significant role in the proliferation and differentiation of various cells and tissues, including ectodermal organs, teeth, and chondrocytes. Recently, MSX2 was found to play important roles in the invasion of cancer cells into adjacent tissues via the epithelial-mesenchymal transition (EMT). However, the role of MSX2 in trophoblastic invasion during placental development has yet to be explored. In the present study, we detected MSX2 expression in cytotrophoblast, syncytiotrophoblast, and extravillous cytotrophoblast cells of first or third trimester human placentas via immunohistochemistry analysis. Furthermore, we found that the in vitro invasive ability of HTR8/SVneo cells was enhanced by exogenous overexpression of MSX2, and that this effect was accompanied by increased protein expression of matrix metalloproteinase-2 (MMP-2), vimentin, and β-catenin. Conversely, treatment of HTR8/SVneo cells with MSX2-specific siRNAs resulted in decreased protein expression of MMP-2, vimentin, and β-catenin, and reduced invasion levels in a Matrigel invasion test. Notably, however, treatment with the MSX2 overexpression plasmid and the MSX2 siRNAs had no effect on the mRNA expression levels of β-catenin. Meanwhile, overexpression of MSX2 and treatment with the MSX2-specific siRNA resulted in decreased and increased E-cadherin expression, respectively, in JEG-3 cells. Lastly, the protein expression levels of MSX2 were significantly lower in human pre-eclamptic placental villi than in the matched control placentas. Collectively, our results suggest that MSX2 may induce human trophoblast cell invasion, and dysregulation of MSX2 expression may be associated with pre-eclampsia.

Dissecting the mechanism of colorectal tumorigenesis based on RNA-sequencing data

OBJECTIVE

This study aimed to identify the differentially expressed genes (DEGs), mutated genes and fusion genes in colorectal cancer.

MATERIALS AND METHODS

RNA-sequencing data (ID: SRP009386) from cancerous, paracancerous non-tumor and distant normal tissue from one Chinese patient with stage III colorectal cancer were downloaded from Sequence Read Archive. Quality control was checked using FastQC, followed by sequence alignment against the hg19 reference genome using TopHat v1.3.3. The expression levels were quantified using Cufflinks, followed by DEGs screening using NOISeq. Enrichment analysis was performed using DAVID. Transcription factors were screened using TRANSFA. Mutated loci were identified using SAMTools and VCFTools. Gene fusion events were detected by TopHat-fusion.

RESULTS

In total 2440, 1887 and 834 DEGs were respectively detected in cancerous vs. normal tissue, cancerous vs. paracancerous tissue and paracancerous vs. normal tissue. The up-regulated genes from cancerous and paracancerous tissue compared with normal tissue were enriched in "extracellular matrix receptor interaction" and "focal adhesion pathway" as well as some biological processes except for "negative regulation of programmed cell death" uniquely presenting in cancer. Dysregulated transcription factors including SOX4, BCL6, CEBPB and MSX2 were enriched in the unique biological process. Trp53 was identified with one mutated locus 7577142 (C → T) on chromosome 17. BCL6 also experienced missense mutation. Additionally, COL1A1-PPP2R2C and EXPH5-COL1A2 were observed fusion genes in cancer tissue.

CONCLUSIONS

The unique biological process in cancer tissue may be the cause for colorectal carcinogenesis. The screened transcription factors, mutated genes and fusion genes may contribute to the progression of colorectal cancer.