Smoc2 potentiates proliferation of hepatocellular carcinoma cells via promotion of cell cycle progression

Comprehensive meta-analysis reveals distinct gene expression signatures of MASLD progression

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its progressive form, metabolic dysfunction-associated steatohepatitis (MASH), pose significant risks of severe fibrosis, cirrhosis, and hepatocellular carcinoma. Despite their widespread prevalence, the molecular mechanisms underlying the development and progression of these common chronic hepatic conditions are not fully understood. Here, we conducted the most extensive meta-analysis of hepatic gene expression datasets from liver biopsy samples to date, integrating 10 RNA-sequencing and microarray datasets (1,058 samples). Using a random-effects meta-analysis model, we compared over 12,000 shared genes across datasets. We identified 685 genes differentially expressed in MASLD versus normal liver, 1,870 in MASH versus normal liver, and 3,284 in MASLD versus MASH. Integrating these results with genome-wide association studies and coexpression networks, we identified two functionally relevant, validated coexpression modules mainly driven by SMOC2, ITGBL1, LOXL1, MGP, SOD3, and TAT, HGD, SLC25A15, respectively, the latter not previously associated with MASLD and MASH. Our findings provide a comprehensive and robust analysis of hepatic gene expression alterations associated with MASLD and MASH and identify novel key drivers of MASLD progression.

Proinflammatory Bone Marrow Mesenchymal Stem Cell-Derived Exosomal miR-150-3p Suppresses Proinflammatory Polarization of Alveolar Macrophages in Sepsis by Targeting Inhibin Subunit Beta A

Bone marrow mesenchymal stem cell (BMSC)-derived exosomes can protect lung tissues against sepsis, but its related mechanism remains elusive. BMSCs were primed with or without lipopolysaccharide (LPS) before extracting exosomes. The isolated exosomes were identified by transmission electron microscopy, nanoparticle tracking analysis, and western blot. LPS-stimulated macrophages were cocultured with exosomes for 24 h, followed by enzyme-linked immunosorbent assay, flow cytometry, and molecular experiments. Bioinformatics and luciferase assay were employed to investigate the interaction between miR-150-3p and inhibin subunit beta A (INHBA). MiR-150-3p expression was increased in exosomes in a proinflammatory environment. Exosomes suppressed proinflammatory polarization by downregulating IL-6, IL-1β, iNOS, and CD86, as well as promoted anti-inflammatory polarization by upregulating IL-10, ARG-1, and CD206 in LPS-stimulated macrophages. Such effects were more pronounced by LPS-primed exosomes, which was reversed in the absence of miR-150-3p. MiR-150-3p targeted INHBA. INHBA silencing decreased CD86 expression and increased CD206 expression in macrophages, but these effects were reversed by exosomal miR-150-3p inhibition. Proinflammatory BMSC-derived exosomal miR-150-3p suppressed proinflammatory polarization and promoted anti-inflammatory polarization of alveolar macrophages to attenuate LPS-induced sepsis by targeting INHBA.

Myosin heavy chain-derived peptide of Gadus morhua promotes proliferation and differentiation in osteoblasts and bone formation and maintains bone homeostasis in ovariectomized mice

Gadus morhua is an important commercial fish rich in nutrients required for daily metabolism. However, the regulation of G. morhua peptides (GMP) on osteoblast growth remains unclear. In order to clarify the regulatory effects of GMP on osteoblasts, the effects of GMP on the growth of MC3T3-E1 cells were investigated, and the osteogenic peptides were identified and screened. The results showed that GMP promoted the proliferation and differentiation of osteoblasts by regulating the BMP/WNT signaling pathway at concentrations of 1-100 μg mL^-1. Molecular docking studies showed that a decapeptide, MNKKREAEFQ (P-GM-1), had a high affinity for integrins 3VI4 and 1L5G (-CDOCKER interaction energy: 161.30, 212.27 kcal mol^-1). Additionally, the proliferation rate of MC3T3-E1 cells was increased by 27%, and ALP activity was significantly increased under P-GM-1 treatment (100 μg mL^-1). Moreover, P-GM-1 promotes bone formation, maintains bone homeostasis, and prevents osteoporosis in ovariectomized mice by regulating the BMP/Smad signaling pathway. This study confirmed the potential of GMP in the regulation of bone mineral density and provided a certain theoretical basis for the development of anti-osteoporosis active factors from GMP.

Stellate cell expression of SPARC-related modular calcium-binding protein 2 is associated with human non-alcoholic fatty liver disease severity

Background & Aims

Histological assessment of liver biopsies is the gold standard for diagnosis of non-alcoholic steatohepatitis (NASH), the progressive form of non-alcoholic fatty liver disease (NAFLD), despite its well-established limitations. Therefore, non-invasive biomarkers that can offer an integrated view of the liver are needed to improve diagnosis and reduce sampling bias. Hepatic stellate cells (HSCs) are central in the development of hepatic fibrosis, a hallmark of NASH. Secreted HSC-specific proteins may, therefore, reflect disease state in the NASH liver and serve as non-invasive diagnostic biomarkers.

Methods

We performed RNA-sequencing on liver biopsies from a histologically characterised cohort of obese patients (n = 30, BMI >35 kg/m²) to identify and evaluate HSC-specific genes encoding secreted proteins. Bioinformatics was used to identify potential biomarkers and their expression at single-cell resolution. We validated our findings using single-molecule fluorescence in situ hybridisation (smFISH) and ELISA to detect mRNA in liver tissue and protein levels in plasma, respectively.

Results

Hepatic expression of SPARC-related modular calcium-binding protein 2 (SMOC2) was increased in NASH compared to no-NAFLD (p.adj <0.001). Single-cell RNA-sequencing data indicated that SMOC2 was primarily expressed by HSCs, which was validated using smFISH. Finally, plasma SMOC2 was elevated in NASH compared to no-NAFLD (p <0.001), with a predictive accuracy of AUROC 0.88.

Conclusions

Increased SMOC2 in plasma appears to reflect HSC activation, a key cellular event associated with NASH progression, and may serve as a non-invasive biomarker of NASH.

Impact and implications

Non-alcoholic fatty liver disease (NAFLD) and its progressive form, non-alcoholic steatohepatitis (NASH), are the most common forms of chronic liver diseases. Currently, liver biopsies are the gold standard for diagnosing NAFLD. Blood-based biomarkers to complement liver biopsies for diagnosis of NAFLD are required. We found that activated hepatic stellate cells, a cell type central to NAFLD pathogenesis, upregulate expression of the secreted protein SPARC-related modular calcium-binding protein 2 (SMOC2). SMOC2 was elevated in blood samples from patients with NASH and may hold promise as a blood-based biomarker for the diagnosis of NAFLD.

Matricellular Protein SMOC2 Potentiates BMP9-Induced Osteogenic Differentiation in Mesenchymal Stem Cells through the Enhancement of FAK/PI3K/AKT Signaling

Mesenchymal stem cells (MSCs) can self-renew and differentiate into multiple lineages, making MSC transplantation a promising option for bone regeneration. Both matricellular proteins and growth factors play an important role in regulating stem cell fate. In this study, we investigated the effects of matricellular protein SMOC2 (secreted modular calcium-binding protein 2) on bone morphogenetic protein 9 (BMP9) in mouse embryonic fibroblasts (MEFs) and revealed a possible molecular mechanism underlying this process. We found that SMOC2 was detectable in MEFs and that exogenous SMOC2 expression potentiated BMP9-induced osteogenic markers, matrix mineralization, and ectopic bone formation, whereas SMOC2 knockdown inhibited these effects. BMP9 increased the levels of p-FAK and p-AKT, which were either enhanced or reduced by SMOC2 and FAK silencing, respectively. BMP9-induced osteogenic markers were increased by SMOC2, and this increase was partially abolished by silencing FAK or LY290042. Furthermore, we found that general transcription factor 2I (GTF2I) was enriched at the promoter region of SMOC2 and that integrin β1 interacted with SMOC2 in BMP9-treated MEFs. Our findings demonstrate that SMOC2 can promote BMP9-induced osteogenic differentiation by enhancing the FAK/PI3K/AKT pathway, which may be triggered by facilitating the interaction between SMOC2 and integrin β1.

SMOC2 promotes aggressive behavior of fibroblast-like synoviocytes in rheumatoid arthritis through transcriptional and post-transcriptional regulating MYO1C

Fibroblast-like synoviocytes (FLSs), play a key role in perpetuating synovial inflammation and bone erosion in rheumatoid arthritis (RA), however, the underlying mechanism(s) of RA FLSs activation and aggression remain unclear. Identifying endogenous proteins that selectively target FLSs is urgently needed. Here, we systematically identified that secreted modular calcium-binding protein 2 (SMOC2), was significantly increased in RA FLSs and synovial tissues. SMOC2 knockdown specifically regulated cytoskeleton remodeling and decreased the migration and invasion of RA FLSs. Mechanistically, cytoskeleton-related genes were significantly downregulated in RA FLSs with reduced SMOC2 expression, especially the motor protein myosin1c (MYO1C). SMOC2 controlled MYO1C expression by SRY-related high-mobility group box 4 (SOX4) and AlkB homolog 5 (ALKHB5) mediated-m⁶A modification through transcriptional and post-transcriptional regulation. Furthermore, intra-articular Ad-shRNA-SMOC2 treatment attenuated synovial inflammation as well as bone and cartilage erosion in rats with collagen-induced arthritis (CIA). Our findings suggest that increased SMOC2 expression in FLSs may contribute to synovial aggression and joint destruction in RA. SMOC2 may serve as a potential target against RA. SMOC2-mediated regulation of the synovial migration and invasion in RA FLSs. In RA FLSs, SMOC2 is significantly increased, leading to the increased level of MYO1C via SOX4-mediated transcriptional regulation and ALKBH5-mediated m⁶A modification, thereby causing cytoskeleton remodeling and promoting RA FLSs migration and invasion. The Figure was drawn by Figdraw.

SMOC2 promotes an epithelial-mesenchymal transition and a pro-metastatic phenotype in epithelial cells of renal cell carcinoma origin

Renal Cell Carcinoma (RCC) is the most common form of all renal cancer cases, and well-known for its highly aggressive metastatic behavior. SMOC2 is a recently described non-structural component of the extracellular matrix (ECM) that is highly expressed during tissue remodeling processes with emerging roles in cancers, yet its role in RCC remains elusive. Using gene expression profiles from patient samples, we identified SMOC2 as being significantly expressed in RCC tissue compared to normal renal tissue, which correlated with shorter RCC patient survival. Specifically, de novo protein synthesis of SMOC2 was shown to be much higher in the tubular epithelial cells of patients with biopsy-proven RCC. More importantly, we provide evidence of SMOC2 triggering kidney epithelial cells into an epithelial-to-mesenchymal transition (EMT), a phenotype known to promote metastasis. We found that SMOC2 induced mesenchymal-like morphology and activities in both RCC and non-RCC kidney epithelial cell lines. Mechanistically, treatment of RCC cell lines ACHN and 786-O with SMOC2 (recombinant and enforced expression) caused a significant increase in EMT-markers, -matrix production, -proliferation, and -migration, which were inhibited by targeting SMOC2 by siRNA. We further characterized SMOC2 activation of EMT to occur through the integrin β3, FAK and paxillin pathway. The proliferation and metastatic potential of SMOC2 overexpressing ACHN and 786-O cell lines were validated in vivo by their significantly higher tumor growth in kidneys and systemic dissemination into other organs when compared to their respective controls. In principle, understanding the impact that SMOC2 has on EMT may lead to more evidence-based treatments and biomarkers for RCC metastasis.

LncRNA LINC01857 drives pancreatic adenocarcinoma progression via modulating miR-19a-3p/SMOC2

OBJECTIVES

Emerging evidence has demonstrated that LINC01857 exerts a pivotal function in many cancers. However, its function in Pancreatic Ductal Adenocarcinoma (PDAC) still remains unclear. This study was designed to investigate the regulatory character of LINC01857 in PDAC.

METHODS

Bioinformatic tools and databases were used to seek potential miRNAs and mRNAs. Gene expression was evaluated by Reverse Transcription quantitative real-time Polymerase Chain Reaction (RT-qPCR), and western blot was used for protein level detection. A subcellular fraction assay was done to ascertain the location of LINC01857 in PANC-1 and BxPC-3 human pancreatic cancer cells. CCK-8, EdU, wound healing and Transwell assays were performed to inquire into the influence of LINC01857, and SPARC -related Modular Calcium-binding protein-2 (SMOC2) on cell viability, proliferation, migration, and invasion, respectively. The interaction between LINC01857 and its downstream genes was explored by RNA immunoprecipitation and luciferase reporter assays.

RESULTS

LINC01857 levels were significantly elevated in PDAC. Knockdown of LINC01857 significantly restrained the proliferation, migration, invasion, and Epithelial-Mesenchymal Transition (EMT) process of PDAC cells. MiR-19a-3p was a downstream target of LINC01857, and miR-19a-3p levels were significantly decreased in PDAC cells. In addition, SMOC2 expression had a negative correlation with that of miR-19a-3p, and SMOC2 was a downstream target of miR-19a-3p. Furthermore, SMOC2 upregulation partially abolished the inhibitive influence of LINC01857 downregulation on cell proliferation, migration, invasion, and the EMT process.

CONCLUSION

LINC01857 promotes malignant phenotypes of PDAC cells via upregulation of SMOC2 by interacting with miR-19a-3p.

Identification of metastasis-associated exoDEPs in colorectal cancer using label-free proteomics

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Exosomes play essential role in the metastasis of colorectal cancer from TME aspect.

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Finding out the prominent regulating exoDEPs by label-free proteomics in this research provided a lot of key information of CRC metastases.

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Metabolism, cytoskeleton-related pathways and immunosuppression are two key mechanisms by which exosomes regulate CRC malignant behavior.

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The discovery of the “all or none” exoDEPs was of great significance. The exoDEPs expressed only in SW620 cells can more clearly show their ability to promote the invasion and metastasis of CRC cells.

Exosomes are secreted nanovesicles consisting of biochemical molecules, including proteins, RNAs, lipids, and metabolites that play a prominent role in tumor progression. In this study, we performed a label-free proteomic analysis of exosomes from a pair of homologous human colorectal cancer cell line with different metastatic abilities. A total of 115 exoDEPs were identified, with 31 proteins upregulated and 84 proteins downregulated in SW620 exosome. We also detected 30 proteins expressed only in SW620 exosomes and 60 proteins expressed only in SW480 exosomes. Bioinformatics analysis enriched the components and pathways associated with the extracellular matrix, cytoskeleton-related pathways, and immune system changes of colorectal cancer (CRC). Cellular function experiments confirmed the role of SW620 exosomes in promoting the proliferation, migration, and invasion of SW480 cells. Further verifications were performed on six upregulated exoDEPs (FGFBP1, SIPA1, THBS1, TGFBI, COL6A1, and RPL10), three downregulated exoDEPs (SLC2A3, MYO1D, and RBP1), and three exoDEPs (SMOC2, GLG1, and CEMIP) expressed only in SW620 by WB and IHC. This study provides a complete and novel basis for exploring new drug targets to inhibit the invasion and metastasis of CRC.

Hsa_circ_0074298 promotes pancreatic cancer progression and resistance to gemcitabine by sponging miR-519 to target SMOC

Objective: To investigate the expression of hsa_circ_0074298 (circular RNA) and the molecular mechanism that promotes tumor growth and enhances the chemoresistance of pancreatic cancer.

Methods: Real-time reverse transcription-PCR was used to detect hsa_circ_0074298 expression in pancreatic cancer. The intracellular localization of hsa_circ_0074298 was determined by RNA in situ hybridization. The CCK8 method, colony formation assay, Transwell assay, and flow cytometry were used to evaluate the effects of hsa_circ_0074298 on the proliferation, migration, invasion, cell cycle, apoptosis of pancreatic cancer cells. Bioinformatics analysis and dual luciferase assays were employed to detect the association of hsa_circ_0074298 and miR-519d and the binding of miR-519d to the target gene SMOC2. A subcutaneous xenograft model was established to observe the effect of hsa_circ_0074298 in vivo.

Results: The hsa_circ_0074298 was mainly localized in the cytoplasm. Hsa_circ_0074298 was highly expressed in pancreatic cancer tissues and cell lines. The expression of hsa_circ_0074298 was significantly correlated with pancreatic cancer tumor size, lymph node metastasis, and pathological grade. hsa_circ_0074298 could sponge miR-519, and miR-519d bound to SMOC2. Downregulation of hsa_circ_0074298 expression significantly inhibited cell proliferation, migration, invasion, colony forming ability and promoted cell cycle arrest, apoptosis and chemo-resistance of pancreatic cancer in vitro and vivo. However, the effects could be reversed by a miR-519d inhibitor or SMOC2 overexpression.

Conclusion: By sponging miR-519 and targeting SMOC2, hsa_circ_0074298 promotes the growth and metastasis of pancreatic cancer and increases the resistance of pancreatic cancer cells to gemcitabine.

Prognostic Potential of Secreted Modular Calcium-Binding Protein 1 in Low-Grade Glioma

Background: Secreted modular calcium-binding protein 1 (SMOC1) belongs to a family of matricellular proteins; it was involved in embryo development, endothelial cell proliferation, angiogenesis, integrin–matrix interactions, cell adhesion, and regulation of glucose metabolism. Previous studies showed that the expression of SMOC1 was increased in some tumors. However, the prognostic value and the biological function of SMOC1 in tumor remain unclear.

Methods: In this study, we explored the expression profile and prognostic value of SMOC1 in pan-cancers, especially glioma, via multiple databases, including Oncomine, Gene Expression Profiling Interactive 2, PrognoScan, Kaplan–Meier plotter, and the Chinese Glioma Genome Atlas database. Furthermore, LinkedOmics was used to identify the genes coexpressed with SMOC1 and to perform Kyoto Encyclopedia of Genes and Genomes pathways and Gene Ontology analysis in low-grade glioma (LGG). Also, the Cancer Single-Cell State Atlas database was used to evaluate the correlation between SMOC1 expression and functional state activities in glioma cells. In addition, the Tumor Immune Estimation Resource and TISIDB databases were used to evaluate the correlations between SMOC1 expression and tumor-infiltrating immune cells in the tumor microenvironment.

Results: Compared with normal brain tissues, the expression of SMOC1 was increased in LGG tissues. The higher expression of SMOC1 was significantly correlated with better survival of LGG patients. Additionally, functional analyses showed that the SMOC1 coexpressed genes were inhibited in processes such as response to type I interferon and interferon-gamma, lymphocyte-mediated immunity, leukocyte migration, adaptive immune response, neutrophil-mediated immunity, T cell activation, and pathways including EMC–receptor interaction, Th17 cell differentiation, and leukocyte trans-endothelial migration in LGG. Moreover, the expression of SMOC1 was correlated with stemness, hypoxia, EMT, and metastasis of glioma cells. Additionally, the expression of SMOC1 expression was negatively correlated with levels of infiltrating B cells, CD8⁺ T cells, CD4⁺ T cells, macrophages, neutrophils and dendritic cells, and gene markers of most immune cells in LGG.

Conclusion: Our results suggest that SMOC1 could be a potential biomarker to determine prognosis and might play a specific role in the tumor microenvironment of glioma, thereby influencing the development and progression of glioma. These findings provide some new insights for further investigation.

Novel Methylation Biomarkers for Colorectal Cancer Prognosis

Colorectal cancer (CRC) comprises the third most common cancer worldwide and the second regarding number of deaths. In order to make a correct and early diagnosis to predict metastasis formation, biomarkers are an important tool. Although there are multiple signaling pathways associated with cancer progression, the most recognized are the MAPK pathway, p53 pathway, and TGF-β pathway. These pathways regulate many important functions in the cell, such as cell cycle regulation, proliferation, differentiation, and metastasis formation, among others. Changes in expression in genes belonging to these pathways are drivers of carcinogenesis. Often these expression changes are caused by mutations; however, epigenetic changes, such as DNA methylation, are increasingly acknowledged to play a role in the deregulation of oncogenic genes. This makes DNA methylation changes an interesting biomarkers in cancer. Among the newly identified biomarkers for CRC metastasis INHBB, SMOC2, BDNF, and TBRG4 are included, all of which are highly deregulated by methylation and closely associated with metastasis. The identification of such biomarkers in metastasis of CRC may allow a better treatment and early identification of cancer formation in order to perform better diagnostics and improve the life expectancy.

Extensive remodeling of the extracellular matrix during aging contributes to age-dependent impairments of muscle stem cell functionality

During aging, the regenerative capacity of skeletal muscle decreases due to intrinsic changes in muscle stem cells (MuSCs) and alterations in their niche. Here, we use quantitative mass spectrometry to characterize intrinsic changes in the MuSC proteome and remodeling of the MuSC niche during aging. We generate a network connecting age-affected ligands located in the niche and cell surface receptors on MuSCs. Thereby, we reveal signaling by integrins, Lrp1, Egfr, and Cd44 as the major cell communication axes perturbed through aging. We investigate the effect of Smoc2, a secreted protein that accumulates with aging, primarily originating from fibro-adipogenic progenitors. Increased levels of Smoc2 contribute to the aberrant Integrin beta-1 (Itgb1)/mitogen-activated protein kinase (MAPK) signaling observed during aging, thereby causing impaired MuSC functionality and muscle regeneration. By connecting changes in the proteome of MuSCs to alterations of their niche, our work will enable a better understanding of how MuSCs are affected during aging.

Ixazomib inhibits myeloma cell proliferation by targeting UBE2K

PURPOSE

Ixazomib is a selective, effective, and reversible inhibitor of 20S proteasome and is approved for the treatment of multiple myeloma. Ubiquitin-conjugating enzyme E2 (UBE2K) is involved in the synthesis of K48-linked ubiquitin chains and is the target of certain drugs used for the treatment of tumors. The purpose of this study was to investigate the relationship between ixazomib and UBE2K in myeloma cells.

METHODS

We used CCK-8 and Annexin V-FITC/propidium iodide kit to detect the effects of ixazomib on survival and apoptosis of RPMI-8226 and U-266 myeloma cell lines. Quantitative polymerase chain reaction and western blot were used to detect the change in gene and protein expression levels of myeloma cells treated with ixazomib. Furthermore, the regulatory effects of ixazomib on UBE2K and its downstream targets were investigated following the overexpression of UBE2K.

RESULTS

In myeloma cells, ixazomib decreased cell survival and increased apoptosis in a dose-dependent manner. Ixazomib significantly increased the expression of HIST1H2BD, MNAT1, NEK3, and TARS2, while decreasing the expression of HSPA1B and UBE2K. In addition, ixazomib inhibited the proliferation of myeloma cells, blocked cell cycle, induced cell apoptosis, and increased the production of reactive oxygen species by inhibiting UBE2K expression. Lastly, ixazomib regulates mitosis- and apoptosis-related genes by lowering UBE2K expression.

CONCLUSION

In summary, ixazomib leads to impaired proliferation of myeloma cells by targeting UBE2K.

Deficiency of the SMOC2 matricellular protein impairs bone healing and produces age-dependent bone loss

Secreted extracellular matrix components which regulate craniofacial development could be reactivated and play roles in adult wound healing. We report a patient with a loss-of-function of the secreted matricellular protein SMOC2 (SPARC related modular calcium binding 2) presenting severe oligodontia, microdontia, tooth root deficiencies, alveolar bone hypoplasia, and a range of skeletal malformations. Turning to a mouse model, Smoc2-GFP reporter expression indicates SMOC2 dynamically marks a range of dental and bone progenitors. While germline Smoc2 homozygous mutants are viable, tooth number anomalies, reduced tooth size, altered enamel prism patterning, and spontaneous age-induced periodontal bone and root loss are observed in this mouse model. Whole-genome RNA-sequencing analysis of embryonic day (E) 14.5 cap stage molars revealed reductions in early expressed enamel matrix components (Odontogenic ameloblast-associated protein) and dentin dysplasia targets (Dentin matrix acidic phosphoprotein 1). We tested if like other matricellular proteins SMOC2 was required for regenerative repair. We found that the Smoc2-GFP reporter was reactivated in adjacent periodontal tissues 4 days after tooth avulsion injury. Following maxillary tooth injury, Smoc2^−/− mutants had increased osteoclast activity and bone resorption surrounding the extracted molar. Interestingly, a 10-day treatment with the cyclooxygenase 2 (COX2) inhibitor ibuprofen (30 mg/kg body weight) blocked tooth injury-induced bone loss in Smoc2^−/− mutants, reducing matrix metalloprotease (Mmp)9. Collectively, our results indicate that endogenous SMOC2 blocks injury-induced jaw bone osteonecrosis and offsets age-induced periodontal decay.

SMOC2, an intestinal stem cell marker, is an independent prognostic marker associated with better survival in colorectal cancers

We aimed to investigate the expression profile of SPARC-related modular calcium-binding protein 2 (SMOC2) during colorectal cancer (CRC) progression and assess its prognostic impact in CRC patients. In our study, we showed that SMOC2 transcript level was higher in CRC samples than in normal mucosa (P = 0.017); this level was not associated with candidate cancer stem cell markers (CD44, CD166, CD133, and CD24) or intestinal stem cell markers (LGR5, ASCL2, and EPHB2) except for OLFM4 (P = 0.04). Immunohistochemical analysis showed that SMOC2-positive cells were confined to the crypt bases in the normal intestinal mucosa, hyperplastic polyps, and sessile serrated adenomas, whereas traditional serrated adenomas and conventional adenomas exhibited focal or diffuse distribution patterns. In total, 28% of 591 CRCs were positive for SMOC2, but SMOC2 positivity had negative correlations with lymphatic invasion (P = 0.002), venous invasion (P = 0.002), and tumor stage (P < 0.001). However, a positive association with nuclear β-catenin expression was seen. Furthermore, while upregulated SMOC2 expression was maintained during the adenoma-carcinoma transition, it decreased in cancer cells at the invasive front but did not decline further during lymph node metastasis. SMOC2 positivity showed no correlations with molecular abnormalities, including microsatellite instability, CpG island methylator phenotype, and mutations of KRAS and BRAF. In addition, we showed comprehensively that SMOC2 positivity is an independent prognostic marker for better clinical outcomes in a large cohort of CRC patients (P = 0.006). In vitro studies also demonstrated that induced SMOC2 expression in DLD1 cells exerts a suppressive role in tumor growth as well as in migration, colony, and sphere formation abilities. Taken together, our results suggest SMOC2 as a candidate tumor suppressor in CRC progression.

Secreted modular calcium-binding proteins in pathophysiological processes and embryonic development

Objective:

Secreted modular calcium-binding proteins (SMOCs) are extracellular glycoproteins of the secreted protein, acidic, and rich in cysteine-related modular calcium-binding protein family and include two isoforms, SMOC1 and SMOC2, in humans. Functionally, SMOCs bind to calcium for various cell functions. In this review, we provided a summary of the most recent advancements in and findings of SMOC1 and SMOC2 in development, homeostasis, and disease states.

Data sources:

All publications in the PubMed database were searched and retrieved (up to July 24, 2019) using various combinations of keywords searching, including SMOC1, SMOC2, and diseases.

Study selection:

All original studies and review articles of SMOCs in human diseases and embryo development written in English were retrieved and included.

Results:

SMOC1 and SMOC2 regulate embryonic development, cell homeostasis, and disease pathophysiology. They play an important role in the regulation of cell cycle progression, cell attachment to the extracellular matrix, tissue fibrosis, calcification, angiogenesis, birth defects, and cancer development.

Conclusions:

SMOC1 and SMOC2 are critical regulators of many cell biological processes and potential therapeutic targets for the control of human cancers and birth defects.

The Matrix Revolution: Matricellular Proteins and Restructuring of the Cancer Microenvironment

The extracellular matrix (ECM) surrounding cells is indispensable for regulating their behavior. The dynamics of ECM signaling are tightly controlled throughout growth and development. During tissue remodeling, matricellular proteins (MCP) are secreted into the ECM. These factors do not serve classical structural roles, but rather regulate matrix proteins and cell-matrix interactions to influence normal cellular functions. In the tumor microenvironment, it is becoming increasingly clear that aberrantly expressed MCPs can support multiple hallmarks of carcinogenesis by interacting with various cellular components that are coupled to an array of downstream signals. Moreover, MCPs also reorganize the biomechanical properties of the ECM to accommodate metastasis and tumor colonization. This realization is stimulating new research on MCPs as reliable and accessible biomarkers in cancer, as well as effective and selective therapeutic targets.

Downregulation of SMOC2 expression in papillary thyroid carcinoma and its prognostic significance

Secreted Protein Acidic and Rich in Cysteine (SPARC)-related modular calcium-binding protein-2 (SMOC2), a secreted matricellular protein, is reported to be involved in various processes related to cancer progression such as regulating the cell cycle, angiogenesis, and invasion. However, its expression and prognostic significance in papillary thyroid carcinomas (PTCs) remains unknown. Using immunohistochemistry, we evaluated the expression profile of SMOC2 and its prognostic value in a large cohort of PTCs. Real time-PCR analysis with fresh-frozen tissues showed that SMOC2 mRNA expression in PTCs was substantially lower than the expression in matched non-cancerous thyroid tissues, consistent with the results from thyroid cancer cell lines. Immunohistochemical analysis demonstrated that SMOC2 was normally present in thyroid follicular epithelial cells and the expression level was maintained in nodular hyperplasia. However, SMOC2 expression was significantly lower in lymphocytic thyroiditis and follicular tumors including follicular adenomas and carcinomas. In particular, 38% of PTCs exhibited a complete loss of SMOC2 expression, which was associated with the presence of BRAF (V600E) mutation. Moreover, SMOC2 further declined during lymph node metastasis in PTCs. DNA methylation chip analysis revealed one hypermethylated CpG site in the promoter region of SMOC2 gene, suggesting an epigenetic regulation of SMOC2 in PTCs. Remarkably SMOC2 positivity was associated with improved recurrence-free survival along with female sex, tumor size, and the N stage. However, SMOC2 was not identified as an independent prognostic marker in multivariate analyses. Taken together, SMOC2 expression is significantly down-regulated in PTCs and SMOC2 positivity is closely associated with better clinical outcomes, suggesting that SMOC2 can be a prognostic marker in PTC patients.

Aberrant expression of miR‑130a‑3p in ankylosing spondylitis and its role in regulating T‑cell survival

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease. MicroRNAs (miRNAs) are a group of endogenous small non‑coding RNAs that regulate target genes, and play a critical role in many biological processes. However, the underlying mechanism of specific miRNA, miR‑130a‑3p, in AS remains largely unknown. Therefore, the present study aimed to explore the underlying mechanism of miR‑130a‑3p in the development of AS. In the present study, it was revealed that miR‑130a‑3p was downregulated in T cells from HLA‑B27‑positive AS patients compared with the HLA‑B27‑negative healthy controls. Next, bioinformatics software TargetScan 7.2 was used to predict the target genes of miR‑130a‑3p, and a luciferase reporter assay indicated that HOXB1 was the direct target gene of miR‑130a‑3p. Furthermore, it was determined that HOXB1 expression was upregulated in T cells from HLA‑B27‑positive AS patients. In addition, the results of the present study indicated that miR‑130a‑3p inhibitor significantly inhibited cell proliferation ability and induced cell apoptosis of Jurkat T cells, while the miR‑130a‑3p mimic promoted proliferation ability and inhibited cell apoptosis of Jurkat T cells. Notably, all the effects of the miR‑130a‑3p mimic on Jurkat T cells were reversed by HOXB1‑plasmid. Collectively, our data indicated that miR‑130a‑3p was decreased in T cells from AS patients and it could regulate T‑cell survival by targeting HOXB1.

Cyclin-Dependent Kinase Inhibitor 3 Promotes Cancer Cell Proliferation and Tumorigenesis in Nasopharyngeal Carcinoma by Targeting p27

Nasopharyngeal carcinoma (NPC) is a common malignancy of the head and neck that arises from the nasopharynx epithelium and is highly invasive. Cyclin-dependent kinase inhibitor 3 (CDKN3) belongs to the dual-specificity protein phosphatase family, which plays a key role in regulating cell division. Abnormal expression of CDKN3 has been found in numerous types of cancer. In the current study, we explored the possible role of CDKN3 in cell proliferation, ability to invade, and radiosensitivity in NPC cells. We reported that CDKN3 was upregulated and p27 was downregulated in NPC tissues and is associated with a worse prognosis for patients. In addition, downregulation of CDKN3 and upregulation of p27 decreased cell proliferation, induced cell cycle arrest, increased apoptosis, decreased cell invasion, and enhanced radiosensitivity. Silencing of p27 significantly inhibited the effects of the knockdown of CDKN3. Moreover, downregulation of CDKN3 and upregulation of p27 inhibited the increase in tumor volume and weight in implanted tumors, decreased the phosphorylation of Akt, and increased the expression of cleaved caspase 3 in tumors. CDKN3 expression was also inversely correlated with p27 expression in NPC patients. Knockdown of CDKN3 increased p27 expression. Silencing of p27 markedly inhibited the effects of CDKN3 on cell proliferation, cell cycle progression, apoptosis, invasion, and radiosensitivity. These results demonstrate that upregulation of p27 is involved in the knockdown of CDKN3-induced decrease in cell proliferation, increase in cell cycle arrest and apoptosis, decrease in invasion, and increase in radiosensitivity. The results demonstrate that the CDKN3/p27 axis may be a novel target in the treatment of NPC.