miRNA-497 Negatively Regulates the Growth and Motility of Chondrosarcoma Cells by Targeting Cdc25A

The Roles of Noncoding RNAs in the Development of Osteosarcoma Stem Cells and Potential Therapeutic Targets

Osteosarcoma (OS) is the common bone tumor in children and adolescents. Because of chemotherapy resistance, the OS patients have a poor prognosis. The one reason of chemotherapeutic resistance is the development of cancer stem cells (CSCs). CSCs represent a small portion of tumor cells with the capacity of self-renewal and multipotency, which are associated with tumor initiation, metastasis, recurrence and drug resistance. Recently, noncoding RNAs (ncRNAs) have been reported to critically regulate CSCs. Therefore, in this review article, we described the role of ncRNAs, especially miRNAs, lncRNAs and circRNAs, in regulating CSCs development and potential mechanisms. Specifically, we discussed the role of multiple miRNAs in targeting CSCs, including miR-26a, miR-29b, miR-34a, miR-133a, miR-143, miR-335, miR-382, miR-499a, miR-1247, and let-7days. Moreover, we highlighted the functions of lncRNAs in regulating CSCs in OS, such as B4GALT1-AS1, DANCR, DLX6-AS1, FER1L4, HIF2PUT, LINK-A, MALAT1, SOX2-OT, and THOR. Due to the critical roles of ncRNAs in regulation of OS CSCs, targeting ncRNAs might be a novel strategy for eliminating CSCs for OS therapy.

mir-21-5p inhibits the progression of human chondrosarcoma by regulating CCR7/STAT3/NF-κB pathway

Purpose: MicroRNAs (miRNAs or miRs) play an important role in the initiation and development of chondrosarcoma (CS). However, the role of miR-21-5p in CS progression and its underlying molecular mechanisms remains unclear.Materials and Methods: miR-21-5p expression was measured by qRT-PCR. Cell proliferation, migration, and invasion were detected by CCK-8 and Transwell assay. Dual-luciferase reporter assay was used to validate the target of miR-21-5p. Western blot was applied to explore the expressions of CCR7 and EMT biomarkers. Then, the xenograft model was established to confirm the effects of miR-21-5p.Results: miR-21-5p was significantly downregulated in CS tissues and cells and negatively correlated with grade, recurrence, and 5-year overall survival. In vitro, miR-21-5p caused G0/G1 cell cycle arrest and induced apoptosis by decreasing cyclin D1 expression and Bcl-2/Bax ratio. miR-21-5p suppressed cell migration and invasion of CS cells by inhibiting epithelial-mesenchymal transition (EMT). In vivo, miR-21-5p inhibited xenograft tumor formation of SW1353 cells. Mechanistically, miR-21-5p targeted the 3'-UTR of C-C chemokine receptor 7 (CCR7) mRNA to inhibit its expression. Overexpression of CCR7 reversed the inhibitory effects of miR-21-5p on CS cell behaviors. However, the silencing of CCR7 enhanced the inhibitory effects of miR-21-5p on CS cells. Besides, the overexpression of miR-21-5p or silencing of CCR7 obviously reduced the expression levels of p-STAT3, p-p56, and p-IκBα.Conclusion: miR-21-5p targeted CCR7 expression to inhibit the STAT3 and NF-κB signaling, thereby suppressing cell proliferation, migration, invasion, and EMT in CS cells, which might be a novel mechanistic study for CS therapy.Abbreviations: 3'-UTR: 3'-untranslated region; CCR7: C-C chemokine receptor type 7; CS: chondrosarcoma; DMEM: dulbecco's modified eagle's medium; EMT: epithelial-mesenchymal transition; HEK-293T: human embryonic kidney-293T; miR-21-5p: microRNA-21-5p; miR-NC: negative control miRNA; SD: standard deviation; si-CCR7: CCR7 siRNAs.

Circular RNA Profiling Reveals That circRNA_104433 Regulates Cell Growth by Targeting miR-497-5p in Gastric Cancer

BACKGROUND

The role and mechanism of hsa_circRNA_104433 in gastric cancer (GC) are further elucidated.

MATERIALS AND METHODS

CircRNA_104433 was selected by circRNA microarrays and GEO database. qRT-PCR was used to analyze the expression of circRNA_104433 in GC. The role of circRNA_104433 in GC cells was evaluated based on cell cycle progression, cell proliferation, cell apoptosis, and tumor xenograft experiment assay. To explore the mechanisms of circRNA_104433 in GC TCGA database, STRING version, qRT-PCR and luciferase assay were performed. Furthermore, the prognostic value of CDC25A in GC was determined based on the GEO database.

RESULTS

The level of circRNA_104433 showed upregulation in GC tissues, and the expression of it showed a positive correlation with the degree of differentiation and the size of the tumor. Knockdown of circRNA_104433 inhibited cell cycle transition, and cell proliferation, while promoted cell apoptosis in GC. CircRNA_104433 directly binds to miR-497-5p, which directly regulates CDC25A. The median survival period of GC patients with high expression levels of CDC25A was 21.3 months, which was shorter than those with low group expression of CDC25A (35.9 months). The cell cycle proteins CDK1, CDK2, CCNB1, PKMYT1, CDC20, CHEK1 and CDC25A were coexpressed with CDC25A.

CONCLUSION

These findings suggested that knockdown of circRNA_104433 expression suppressed tumor development in GC.

An update on current and future treatment options for chondrosarcoma

Introduction: Human chondrosarcomas (CS; a malignant cartilage-forming bone tumor) respond poorly to chemotherapy and radiation treatment, resulting in high morbidity and mortality rates. Expanded treatment options are urgently needed. Areas covered: This article updates our 2014 review, in which we evaluated the CS treatments available at that time and potential treatment options under investigation. Since then, advances in research findings, particularly from Chinese herbal medicines, may be bringing us closer to more effective therapies for CS. In particular, promising findings have been reported from research targeting platelet-derived growth factor receptor. Expert opinion: Few treatment options exist for CS; chemotherapy is not even an option for unresectable disease, in which 5-year survival rates are just 2%. New information about the multitude of genes and signaling pathways that encourage CS growth, invasion and metastasis are clarifying how certain signaling pathways and plant-derived active compounds, especially molecularly-targeted therapies that inhibit the PDGF receptor, interfering with these biological processes. This review summarizes discoveries from the last 5 years and discusses how these findings are fueling ongoing work into effectively dealing with the disease process and improving the treatment of CS.

IL-10 Could Play a Role in the Interrelation between Diabetes Mellitus and Osteoarthritis

The association between osteoarthritis (OA), obesity and metabolic syndrome suggests an interrelation between OA and diabetes mellitus (DM). Little is known about the role of anti-inflammatory cytokine interleukin (IL)-10 in the interrelation between OA and DM. Hence, the effects of IL-10 under hyperglycemia (HG) and hyperinsulinemia (HI) in human articular chondrocytes (hAC) and chondrosarcoma cell line Okayama University Medical School (OUMS)-27 were examined. HAC and OUMS-27, cultured in normoglycemic (NG) and HG conditions were stimulated with insulin and/or IL-10. Cell survival, metabolic activity, proliferation and extracellular matrix (ECM) synthesis were immunocytochemically examined. No significant differences in vitality of hAC neither in pure NG (NG_w/o) nor HG (HG_w/o) conditions were found. Applying HI and/or IL-10 in both conditions reduced significantly the vitality of hAC but not of OUMS-27. HG impaired significantly hAC metabolism. When combined with HI + IL-10 or IL-10 alone it decreased also significantly hAC proliferation compared to NG_w/o. In OUMS-27 it induced only a trend of impaired proliferation compared to NG_w/o. hAC but not OUMS-27 reduced significantly their collagen type (col) I, SOX9 and proteoglycan (PG) synthesis in HG combined with HI +/− IL-10 compared to NG_w/o. IL-10 could not moderate HI and HG effects. In contrast to hAC OUMS-27 showed limited sensitivity as DM model.

MicroRNA-525 enhances chondrosarcoma malignancy by targeting F-spondin 1

Increasing evidence has suggested that microRNAs (miRNAs; miRs) are extensively involved in the progression of chondrosarcoma (CHS). However, few studies have investigated the functional role of miR-525 in CHS tissues and cells. In the present study, it was discovered that miR-525 levels were decreased in CHS tissues and cells. Dual luciferase assays indicated that F-spondin 1 (SPON1) is a target gene of microRNA (miR)-525. In addition, miR-525 overexpression suppressed SW1353 cell migration and invasion and enhanced SW1353 cell apoptosis. Increased SPON1 expression levels were identified in CHS tissues and cell lines. Furthermore, miR-525 overexpression significantly suppressed the activation of focal adhesion kinase (FAK)/Src/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (Akt) signaling in CHS cells; this suppression led to SPON1 silencing. In comparison, the SPON1 knockdown-mediated inactivation of FAK/Src/PI3K/Akt signaling was inhibited by inhibiting miR-525. In summary, the present study revealed that decreased miR-525 levels could enhance CHS malignancy as decreased miR-525 binding to the 3' untranslated region of SPON1 activates FAK/Src/PI3K/Akt signaling.

MicroRNA-497 inhibits multiple myeloma growth and increases susceptibility to bortezomib by targeting Bcl-2

Multiple myeloma (MM) is a common severe hematopoietic malignancy occuring in aged population. MicroRNA (miR)‑497 was previously reported to contribute to the apoptosis of other cell types, presumably through targeting B‑cell lymphoma 2 (Bcl‑2). In the present study, miRNA and protein expression levels were detected by reverse transcription‑quantitative polymerase chain reaction and western blot analyses, respectively. The cell proliferation and viability was measured using 3‑(4,5‑dimethylthiazol‑2‑yl)‑2, 5‑diphenyltetrazolium bromide and plate clonality assays, and the cell growth cycle was measured with a flow cytometer. Terminal deoxynucleotidyl transferase (TdT)‑mediated dUTP nick‑end‑labeling, Annexin V and caspase‑3 activity assays were performed to examine the cell apoptotic rates. The results showed that miR‑497 was markedly decreased, whereas Bcl‑2 was enhanced in MM tissues and cell lines. miR‑497 targeted Bcl‑2 and affected its downstream apoptosis‑related genes. The overexpression of miR‑497 promoted MM cell apoptosis through cell cycle arrest, and decreased colony genesis ability and viability. In addition, miR‑497 increased the sensitivity of MM cells to bortezomib. Taken together, miR‑497 suppressed MM cell proliferation and promoted apoptosis by directly targeting Bcl‑2 and altering the expression of downstream apoptosis‑related proteins. The combination of miR‑497 and bortezomib may enhance drug sensitivity, serving as a potentially available therapeutic method for MM.

Endothelin-1 promotes epithelial-mesenchymal transition in human chondrosarcoma cells by repressing miR-300

Chondrosarcoma is a malignant tumor of mesenchymal origin predominantly composed of cartilage-producing cells. This type of bone cancer is extremely resistant to radiotherapy and chemotherapy. Surgical resection is the primary treatment, but is often difficult and not always practical for metastatic disease, so more effective treatments are needed. In particular, it would be helpful to identify molecular markers as targets for therapeutic intervention. Endothelin-1 (ET-1), a potent vasoconstrictor, has been shown to enhance chondrosarcoma angiogenesis and metastasis. We report that ET-1 promotes epithelial–mesenchymal transition (EMT) in human chondrosarcoma cells. EMT is a key pathological event in cancer progression, during which epithelial cells lose their junctions and apical-basal polarity and adopt an invasive phenotype. Our study verifies that ET-1 induces the EMT phenotype in chondrosarcoma cells via the AMP-activated protein kinase (AMPK) pathway. In addition, we show that ET-1 increases EMT by repressing miR-300, which plays an important role in EMT-enhanced tumor metastasis. We also show that miR-300 directly targets Twist, which in turn results in a negative regulation of EMT. We found a highly positive correlation between ET-1 and Twist expression levels as well as tumor stage in chondrosarcoma patient specimens. Therefore, ET-1 may represent a potential novel molecular therapeutic target in chondrosarcoma metastasis.

Synergistic anti-proliferative effects of mTOR and MEK inhibitors in high-grade chondrosarcoma cell line OUMS-27

Chondrosarcoma is a malignant bone tumor that produces cartilaginous neoplastic tissue. Owing to the absence of an effective adjuvant therapy, high-grade chondrosarcoma has a poor prognosis. Therefore, it is important to develop an effective adjuvant therapy to prevent the recurrence and metastasis. Mammalian target of rapamycin (mTOR), a central regulator of cell growth, metabolism, proliferation, and survival, is considered an important target for anticancer drug development. The mitogen activated protein kinase (MAPK) pathway is another highly implicated cellular pathway in cancer and is thought to have compensatory effects in response to the inhibition of the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR signaling pathway. We investigated the mechanism of anti-proliferative effect of the mTOR inhibitor rapamycin and MAPK/ERK (MEK) inhibitor PD 0325901, and the combined effect of rapamycin and PD 0325901 on human chondrosarcoma cell line (OUMS-27). Combination therapy with rapamycin and PD 0325901 showed a stronger anti-proliferative effect on OUMS-27 cells than rapamycin monotherapy. We confirmed that the dual inhibition of the PI3K/Akt/mTOR and RAF/MEK/ERK signaling pathways had synergistic anti-proliferative effects in OUMS-27. Our results suggest that combination therapy of mTOR and MEK inhibitor could be an effective therapeutic approach against chondrosarcoma.

A role for intracellular and extracellular DEK in regulating hematopoiesis

PURPOSE OF REVIEW

Hematopoietic stem/progenitor cell fate decision during hematopoiesis is regulated by intracellular and extracellular signals such as transcription factors, growth factors, and cell-to-cell interactions. In this review, we explore the function of DEK, a nuclear phosphoprotein, on gene regulation. We also examine how DEK is secreted and internalized by cells, and discuss how both endogenous and extracellular DEK regulates hematopoiesis. Finally, we explore what currently is known about the regulation of DEK during inflammation.

RECENT FINDINGS

DEK negatively regulates the proliferation of early myeloid progenitor cells but has a positive effect on the differentiation of mature myeloid cells. Inflammation regulates intracellular DEK concentrations with inflammatory stimuli enhancing DEK expression. Inflammation-induced nuclear factor-kappa B activation is regulated by DEK, resulting in changes in the production of other inflammatory molecules such as IL-8. Inflammatory stimuli in turn regulates DEK secretion by cells of hematopoietic origin. However, how inflammation-induced expression and secretion of DEK regulates hematopoiesis remains unknown.

SUMMARY

Understanding how DEK regulates hematopoiesis under both homeostatic and inflammatory conditions may lead to a better understanding of the biology of HSCs and HPCs. Furthering our knowledge of the regulation of hematopoiesis will ultimately lead to new therapeutics that may increase the efficacy of hematopoietic stem cell transplantation.

Linc00152 promotes malignant progression of glioma stem cells by regulating miR-103a-3p/FEZF1/CDC25A pathway

BACKGROUND

Glioma is one of the most frequent intracranial malignant tumors. LncRNAs have been identified as new modulators in the origination and progression of glioma.

METHODS

Quantitative real-time PCR were conducted to evaluate the expression of linc00152 and miRNA-103a-3p in glioma tissues and cells. Western blot were used to determine the expression of FEZF1 and CDC25A in glioma tissues and cells. Stable knockdown of linc00152 or over-expression of miR-103a-3p in glioma stem cells (GSCs) were established to explore the function of linc00152 and miR-103a-3p in GSCs. Further, luciferase reports were used to investigate the correlation between linc00152 and miR-103a-3p. Cell Counting Kit-8, transwell assays, and flow cytometry were used to investigate the function of linc00152 and miR-103a-3p in GSC malignant biological behaviors. ChIP assays were employed to ascertain the correlations between FEZF1 and CDC25A.

RESULTS

Linc00152 was up-regulated in glioma tissues as well as in GSCs. Knockdown of linc00152 inhibited cell proliferation, migration and invasion, while promoted GSC apoptosis. Linc00152 regulated the malignant behavior of GSCs by binding to miR-103a-3p, which functions as a tumor suppressor. In addition, knockdown of linc00152 down-regulated forebrain embryonic zinc finger protein 1 (FEZF1), a direct target of miR-103a-3p which played an oncogenic role in GSCs. FEZF1 elevated promoter activities and up-regulated expression of the oncogenic gene cell division cycle 25A (CDC25A). CDC25A over-expression activated the PI3K/AKT pathways, which regulated the malignant behavior of GSCs.

CONCLUSIONS

Linc00152/miR-103a-3p/FEZF1/CDC25A axis plays a novel role in regulating the malignant behavior of GSCs, which may be a new potential therapeutic strategy for glioma therapy.

MicroRNA-342-3p Inhibits the Proliferation, Migration, and Invasion of Osteosarcoma Cells by Targeting Astrocyte-Elevated Gene-1 (AEG-1)

Recent studies suggest that microRNAs (miRNAs) are critical regulators in many types of cancer, including osteosarcoma. miR-342-3p has emerged as an important cancer-related miRNA in several types of cancers. However, the functional significance of miR-342-3p in osteosarcoma is unknown. The aims of this study were to investigate whether miR-342-3p is dysregulated in osteosarcoma and to explore the biological function of miR-342-3p in regulating cellular processes of osteosarcoma cells. We found that miR-342-3p expression was significantly decreased in osteosarcoma tissues and cell lines. Overexpression of miR-342-3p inhibits the proliferation, migration, and invasion of osteosarcoma cells. In contrast, the inhibition of miR-342-3p exhibited the opposite effect. Astrocyte-elevated gene-1 (AEG-1) was identified as one of the target genes of miR-342-3p in osteosarcoma cells by bioinformatics analysis, dual-luciferase reporter assay, real-time quantitative polymerase chain reaction, and Western blot analysis. Overexpression of miR-342-3p also inhibited the Wnt and nuclear factor κB signaling pathways. Moreover, overexpression of AEG-1 partially rescued the inhibitory effects of miR-342-3p mediated on the proliferation, migration, and invasion of osteosarcoma cells. Overall, our results show that miR-342-3p inhibits the proliferation, migration, and invasion of osteosarcoma cells through targeting AEG-1, suggesting a potential target for the development of miRNA-based therapy for osteosarcoma.