Exosomal-miR-522-3p derived from cancer-associated fibroblasts accelerates tumor metastasis and angiogenesis via repression bone morphogenetic protein 5 in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a gastrointestinal tract malignancy. Exosomes secreted by cancer-associated fibroblasts (CAFs) are reported to participate in tumor progression by delivering noncoding RNA or small proteins. However, the function of exosomal miR-522-3p in CRC remains unclear.

METHODS

CAFs were derived from tumor tissues, and exosomes were identified by western blot or TEM/NTA and originated from CAFs/NFs. The viability, invasion, and migration of HUVECs and CRC cells was examined using MTT, Transwell, and wound healing assays, respectively. The molecular interactions were validated using dual luciferase reporter assay and RIP. Xenograft and lung metastasis mouse models were generated to assess tumor growth and metastasis.

RESULTS

Exosomes extracted from CAFs/NFs showed high expression of CD63, CD81, and TSG101. CAF-derived exosomes significantly increased the viability, angiogenesis, invasion, and migration of HUVECs and CRC cells, thereby aggravating tumor growth, invasion, and angiogenesis in vivo. miR-522-3p was upregulated in CAF-derived exosomes and CRC tissues. Depletion of miR-522-3p reversed the effect of exosomes derived from CAFs in migration, angiogenesis, and invasion of HUVECs and CRC cells. Furthermore, bone morphogenetic protein 5 (BMP5) was identified as a target gene of miR-522-3p, and upregulation of BMP5 reversed the promoting effect of miR-522-3p mimics or CAF-derived exosomes on cell invasion, migration, and angiogenesis of HUVECs and CRC cells.

CONCLUSION

Exosomal miR-522-3p from CAFs promoted the growth and metastasis of CRC through downregulating BMP5, which might provide new strategies for the treatment of CRC.

G9a Knockdown Suppresses Cancer Aggressiveness by Facilitating Smad Protein Phosphorylation through Increasing BMP5 Expression in Luminal A Type Breast Cancer

Epigenetic abnormalities affect tumor progression, as well as gene expression and function. Among the diverse epigenetic modulators, the histone methyltransferase G9a has been focused on due to its role in accelerating tumorigenesis and metastasis. Although epigenetic dysregulation is closely related to tumor progression, reports regarding the relationship between G9a and its possible downstream factors regulating breast tumor growth are scarce. Therefore, we aimed to verify the role of G9a and its presumable downstream regulators during malignant progression of breast cancer. G9a-depleted MCF7 and T47D breast cancer cells exhibited suppressed motility, including migration and invasion, and an improved response to ionizing radiation. To identify the possible key factors underlying these effects, microarray analysis was performed, and a TGF-β superfamily member, BMP5, was selected as a prominent target gene. It was found that BMP5 expression was markedly increased by G9a knockdown. Moreover, reduction in the migration/invasion ability of MCF7 and T47D breast cancer cells was induced by BMP5. Interestingly, a G9a-depletion-mediated increase in BMP5 expression induced the phosphorylation of Smad proteins, which are the intracellular signaling mediators of BMP5. Accordingly, we concluded that the observed antitumor effects may be based on the G9a-depletion-mediated increase in BMP5 expression and the consequent facilitation of Smad protein phosphorylation.

Bone morphogenetic protein-5, a key molecule that mediates differentiation in MC3T3E1 osteoblast cell line

Bone morphogenetic protein-5 (BMP-5) is a member of the TGF receptor-β family with osteoinductive property. However, its physiological role in osteoblast differentiation is not defined. This study highlights the importance of BMP-5 in MC3T3E1 osteoblast differentiation. Pre-osteoblasts exposed to osteogenic media (ascorbic acid, 50 µg/ml and β-glycerophosphate, 10 mM) showed high protein expression of BMP-5 in cell lysates and cell culture supernatants, which peaked during early time-points of differentiation and declined with onset of mineralization. Attenuation of endogenous BMP-5 protein expression by RNA interference downregulated the expression of type I collagen (COLIA1), an early osteoblast differentiation marker but not osteocalcin, a late osteoblast differentiation marker. Further experiments to analyze the cell signaling components revealed that BMP-5 modulates COLIA1 expression via p38-Runx2 axis involving Runx2 (Ser19) phosphorylation. These effects were also observed when recombinant BMP-5 was added to pre-osteoblast cultures reinforcing the fact that BMP-5 is a modulator of COLIA1 expression. We conclude that BMP-5 has stage-specific role to play during MC3T3E1 osteoblast differentiation in part by autocrine p38/Runx2/COLIA1 signaling. © 2017 BioFactors, 43(4):558-566, 2017.

A distinct regulatory region of the Bmp5 locus activates gene expression following adult bone fracture or soft tissue injury

Bone morphogenetic proteins (BMPs) are key signaling molecules required for normal development of bones and other tissues. Previous studies have shown that null mutations in the mouse Bmp5 gene alter the size, shape and number of multiple bone and cartilage structures during development. Bmp5 mutations also delay healing of rib fractures in adult mutants, suggesting that the same signals used to pattern embryonic bone and cartilage are also reused during skeletal regeneration and repair. Despite intense interest in BMPs as agents for stimulating bone formation in clinical applications, little is known about the regulatory elements that control developmental or injury-induced BMP expression. To compare the DNA sequences that activate gene expression during embryonic bone formation and following acute injuries in adult animals, we assayed regions surrounding the Bmp5 gene for their ability to stimulate lacZ reporter gene expression in transgenic mice. Multiple genomic fragments, distributed across the Bmp5 locus, collectively coordinate expression in discrete anatomic domains during normal development, including in embryonic ribs. In contrast, a distinct regulatory region activated expression following rib fracture in adult animals. The same injury control region triggered gene expression in mesenchymal cells following tibia fracture, in migrating keratinocytes following dorsal skin wounding, and in regenerating epithelial cells following lung injury. The Bmp5 gene thus contains an "injury response" control region that is distinct from embryonic enhancers, and that is activated by multiple types of injury in adult animals.

Expression analysis of BMP2, BMP5, BMP10 in human colon tissues from Hirschsprung disease patients

OBJECTIVE

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor β (TGF β) superfamily. BMP2, BMP5 and BMP10 exert their biological functions by interacting with membrane bound receptors belonging to the serine/threonine kinase family. Hirschsprung disease (HSCR) is characterized by the absence of intramural ganglion cells in the nerve plexuses of the distal gut. However, putative Notch function in enteric nervous system (ENS) development and the etiology of HSCR is unknown.

METHODS

Aganglionic and ganglionic colon segment tissues of 50 HSCR patients were investigated for the expression pattern of BMP2, BMP5 and BMP10 using real-time RT-PCR, Western blot analysis and immunohistochemical staining.

RESULTS

The mRNA levels of BMP2, BMP5 and BMP10 in the stenotic colon segment from HSCR patients were significantly higher than those in the normal ones. Similar increased expressions of them in the stenotic colon segments were detected by Western blotting coupled with densitometry analysis. Lastly, immunohistologicl stain showed significant BMP2, 5 and 10 increases in mucous and muscular layers from stenotic colon segments compared to normal segments.

CONCLUSIONS

BMP2, BMP5 and BMP10 are elevated in the stenotic colon segment of HSCR, and BMPs signaling plays a pivotal role in the development of HSCR.

Genome-wide study reveals an important role of spontaneous autoimmunity, cardiomyocyte differentiation defect and anti-angiogenic activities in gender-specific gene expression in Keshan disease

BACKGROUND

Keshan disease (KD) is an endemic cardiomyopathy in China. The etiology of KD is still under debate and there is no effective approach to preventing and curing this disease. Young women of child-bearing age are the most frequent victims in rural areas. The aim of this study was to determine the differences between molecular pathogenic mechanisms in male and female KD sufferers.

METHODS

We extracted RNA from the peripheral blood mononuclear cells of KD patients (12 women and 4 men) and controls (12 women and 4 men). Then the isolated RNA was amplified, labeled and hybridized to Agilent human 4×44k whole genome microarrays. Gene expression was examined using oligonucleotide microarray analysis. A quantitative polymerase chain reaction assay was also performed to validate our microarray results.

RESULTS

Among the genes differentially expressed in female KD patients we identified: HLA-DOA, HLA-DRA, and HLA-DQA1 associated with spontaneous autoimmunity; BMP5 and BMP7, involved in cardiomyocyte differentiation defect; and ADAMTS 8, CCL23, and TNFSF15, implicated in anti-angiogenic activities. These genes are involved in the canonical pathways and networks recognized for the female KD sufferers and might be related to the pathogenic mechanism of KD.

CONCLUSION

Our results might help to explain the higher susceptibility of women to this disease.

Association study of candidate genes for the progression of hand osteoarthritis

OBJECTIVE

Although a few consistent osteoarthritis (OA) susceptibility genes have been identified, little is known on OA progression. Since OA progression is clinically the most relevant phenotype, we investigate the association between asporin (ASPN), bone morphogenetic protein 5 (BMP5) and growth differentiation factor 5 (GDF5) polymorphisms and progression of hand OA.

METHODS

Single-nucleotide polymorphisms (SNPs) ASPN rs13301537, BMP5 rs373444 and GDF5 rs143383 were genotyped in 251 hand OA patients from the Genetics osteoARthritis and Progression (GARP) study and 725 controls. In a case-control comparison we assessed the association between these SNPs and radiographic progression of hand OA over 6 years, which was based on change in osteophytes or joint space narrowing (JSN), above the smallest detectable change. SNPs with suggestive evidence for association were further analysed for their effect on progression over 2 years, and for the mean change in osteophytes and JSN.

RESULTS

The minor allele of ASPN SNP rs13301537 was associated with hand OA progression over 6 years (odds ratio (OR) (95% CI) 1.49 (1.06-2.07); P = 0.020). The mean change in osteophytes and JSN was higher in carriers of the minor allele compared to homozygous carriers of the common allele with mean difference of 0.73 (95% CI - 0.07-1.56; P = 0.073) and 0.82 (95% CI 0.12-1.52; P = 0.022), respectively. An association with similar effect size was found between ASPN SNP rs13301537 and 2-year progression, and the mean change in osteophytes and JSN was significantly higher in homozygotes.

CONCLUSION

ASPN is associated with hand OA progression. This gives insight in the pathogenesis of hand OA progression and identified a potential target for therapeutic approaches.

Human serine protease HTRA1 positively regulates osteogenesis of human bone marrow-derived mesenchymal stem cells and mineralization of differentiating bone-forming cells through the modulation of extracellular matrix protein

Mammalian high-temperature requirement serine protease A1 (HTRA1) is a secreted member of the trypsin family of serine proteases which can degrade a variety of bone matrix proteins and as such has been implicated in musculoskeletal development. In this study, we have investigated the role of HTRA1 in mesenchymal stem cell (MSC) osteogenesis and suggest a potential mechanism through which it controls matrix mineralization by differentiating bone-forming cells. Osteogenic induction resulted in a significant elevation in the expression and secretion of HTRA1 in MSCs isolated from human bone marrow-derived MSCs (hBMSCs), mouse adipose-derived stromal cells (mASCs), and mouse embryonic stem cells. Recombinant HTRA1 enhanced the osteogenesis of hBMSCs as evidenced by significant changes in several osteogenic markers including integrin-binding sialoprotein (IBSP), bone morphogenetic protein 5 (BMP5), and sclerostin, and promoted matrix mineralization in differentiating bone-forming osteoblasts. These stimulatory effects were not observed with proteolytically inactive HTRA1 and were abolished by small interfering RNA against HTRA1. Moreover, loss of HTRA1 function resulted in enhanced adipogenesis of hBMSCs. HTRA1 Immunofluorescence studies showed colocalization of HTRA1 with IBSP protein in osteogenic mASC spheroid cultures and was confirmed as being a newly identified HTRA1 substrate in cell cultures and in proteolytic enzyme assays. A role for HTRA1 in bone regeneration in vivo was also alluded to in bone fracture repair studies where HTRA1 was found localized predominantly to areas of new bone formation in association with IBSP. These data therefore implicate HTRA1 as having a central role in osteogenesis through modification of proteins within the extracellular matrix.

Genetic variants in CASP3, BMP5, and IRS2 genes may influence survival in prostate cancer patients receiving androgen-deprivation therapy

Several genome-wide association studies (GWAS) have been conducted to identify the common single nucleotide polymorphisms (SNPs) that influence the risk of prostate cancer. It was hypothesized that some prostate cancer-associated SNPs might relate to the clinical outcomes in patients treated for prostate cancer using androgen-deprivation therapy (ADT). A cohort of 601 patients who have received ADT for prostate cancer was genotyped for 29 SNPs that have been associated with prostate cancer in Cancer Genetic Markers of Susceptibility GWAS, and within the genes that have been implicated in cancer. Prognostic significance of these SNPs on the disease progression, prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) after ADT were assessed by Kaplan-Meier analysis and Cox regression model. Three SNPs, namely CASP3 rs4862396, BMP5 rs3734444 and IRS2 rs7986346, were found to be closely associated with the ACM (P≤0.042), and BMP5 rs3734444 and IRS2 rs7986346 were also noted to be significantly related to the PCSM (P≤0.032) after adjusting for the known clinicopathologic predictors. Moreover, patients carrying a greater number of unfavorable genotypes at the loci of interest had a shorter time to ACM and PCSM during ADT (P for trend <0.001). Our results suggest that CASP3 rs4862396, BMP5 rs3734444 and IRS2 rs7986346 may affect the survival in patients after ADT for prostate cancer, and the analysis of these SNPs can help identify patients at higher risk of poor outcome.

Mesenchymal bone morphogenetic protein signaling is required for normal pancreas development

OBJECTIVE

Pancreas organogenesis is orchestrated by interactions between the epithelium and the mesenchyme, but these interactions are not completely understood. Here we investigated a role for bone morphogenetic protein (BMP) signaling within the pancreas mesenchyme and found it to be required for the normal development of the mesenchyme as well as for the pancreatic epithelium.

RESEARCH DESIGN AND METHODS

We analyzed active BMP signaling by immunostaining for phospho-Smad1,5,8 and tested whether pancreas development was affected by BMP inhibition after expression of Noggin and dominant negative BMP receptors in chicken and mouse pancreas.

RESULTS

Endogenous BMP signaling is confined to the mesenchyme in the early pancreas and inhibition of BMP signaling results in severe pancreatic hypoplasia with reduced epithelial branching. Notably, we also observed an excessive endocrine differentiation when mesenchymal BMP signaling is blocked, presumably secondary to defective mesenchyme to epithelium signaling.

CONCLUSIONS

We conclude that BMP signaling plays a previously unsuspected role in the mesenchyme, required for normal development of the mesenchyme as well as for the epithelium.

Shaping skeletal growth by modular regulatory elements in the Bmp5 gene

Cartilage and bone are formed into a remarkable range of shapes and sizes that underlie many anatomical adaptations to different lifestyles in vertebrates. Although the morphological blueprints for individual cartilage and bony structures must somehow be encoded in the genome, we currently know little about the detailed genomic mechanisms that direct precise growth patterns for particular bones. We have carried out large-scale enhancer surveys to identify the regulatory architecture controlling developmental expression of the mouse Bmp5 gene, which encodes a secreted signaling molecule required for normal morphology of specific skeletal features. Although Bmp5 is expressed in many skeletal precursors, different enhancers control expression in individual bones. Remarkably, we show here that different enhancers also exist for highly restricted spatial subdomains along the surface of individual skeletal structures, including ribs and nasal cartilages. Transgenic, null, and regulatory mutations confirm that these anatomy-specific sequences are sufficient to trigger local changes in skeletal morphology and are required for establishing normal growth rates on separate bone surfaces. Our findings suggest that individual bones are composite structures whose detailed growth patterns are built from many smaller lineage and gene expression domains. Individual enhancers in BMP genes provide a genomic mechanism for controlling precise growth domains in particular cartilages and bones, making it possible to separately regulate skeletal anatomy at highly specific locations in the body.

Every bone in the skeleton has a specific shape and size. These characteristic features must be under separate genetic control, because individual bones can undergo striking morphological changes in different species. Researchers have long postulated that the morphology of individual bones arises from the local activity of many separate growth domains around each bone's surface. Differential growth within such domains could modify size, curvature, and formation of specific processes. Here, we show that local growth domains around individual bones are controlled by independent regulatory sequences in bone morphogenetic protein (BMP) genes. We identify multiple regulatory sequences in the Bmp5 gene that control expression in particular bones, rather than all bones. We show that some of these elements are remarkably specific for individual subdomains around the surface of individual bones. Finally, we show that local BMP signaling is necessary and sufficient to trigger highly localized growth patterns in ribs and nasal cartilages. These results suggest that the detailed pattern of growth of individual skeletal structures is encoded in part by multiple regulatory sequences in BMP genes. Gain and loss of anatomy-specific sequences in BMP genes may provide a flexible genomic mechanism for modifying local skeletal anatomy during vertebrate evolution.