Suppressive effect of microRNA-138 on the proliferation and invasion of osteosarcoma cells via targeting SIRT1

The sirtuin family in health and disease

Sirtuins (SIRTs) are nicotine adenine dinucleotide(+)-dependent histone deacetylases regulating critical signaling pathways in prokaryotes and eukaryotes, and are involved in numerous biological processes. Currently, seven mammalian homologs of yeast Sir2 named SIRT1 to SIRT7 have been identified. Increasing evidence has suggested the vital roles of seven members of the SIRT family in health and disease conditions. Notably, this protein family plays a variety of important roles in cellular biology such as inflammation, metabolism, oxidative stress, and apoptosis, etc., thus, it is considered a potential therapeutic target for different kinds of pathologies including cancer, cardiovascular disease, respiratory disease, and other conditions. Moreover, identification of SIRT modulators and exploring the functions of these different modulators have prompted increased efforts to discover new small molecules, which can modify SIRT activity. Furthermore, several randomized controlled trials have indicated that different interventions might affect the expression of SIRT protein in human samples, and supplementation of SIRT modulators might have diverse impact on physiological function in different participants. In this review, we introduce the history and structure of the SIRT protein family, discuss the molecular mechanisms and biological functions of seven members of the SIRT protein family, elaborate on the regulatory roles of SIRTs in human disease, summarize SIRT inhibitors and activators, and review related clinical studies.

Association of sirtuin-1 and vascular endothelial growth factor expression with tumor progression and poor prognosis in liposarcoma

OBJECTIVES

A relationship exists between sirtuin-1 expression and growth and survival of malignant tumors. This study aimed to investigate the prognostic value of sirtuin-1 and vascular endothelial growth factor (VEGF) expression in patients with liposarcoma by examining associations between their expression levels and clinical outcomes.

METHODS

Clinical and histopathological characteristics and follow-up and survival information were retrospectively reviewed for 42 liposarcoma cases. Sirtuin-1 and VEGF protein expression levels were evaluated by immunohistochemistry and their associations with clinical parameters were analyzed using the Spearman-rho test. Univariate and multivariate Cox regression analyses were performed to identify potential prognostic factors. Kaplan-Meier analysis was performed to analyze overall survival.

RESULTS

Sirtuin-1 and VEGF protein expression levels were significantly associated with histological grade, metastasis, and American Joint Committee on Cancer stage. A significant positive correlation was observed between sirtuin-1 and VEGF expression levels (R = 0.677). In univariate analysis, sirtuin-1 and VEGF expression were correlated with shorter overall survival, but the association was significant only for sirtuin-1 (hazard ratio = 3.752, 95% confidence interval 1.553-9.062) in multivariate analysis.

CONCLUSION

Sirtuin-1 and VEGF expression levels are significantly correlated with progression of liposarcoma, and sirtuin-1 expression significantly predicts a poor prognosis in patients with liposarcoma.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

Circular HDAC9/microRNA-138/Sirtuin-1 Pathway Mediates Synaptic and Amyloid Precursor Protein Processing Deficits in Alzheimer's Disease

Synaptic dysfunction and abnormal processing of amyloid precursor protein (APP) are early pathological features in Alzheimer's disease (AD). Recently, non-coding RNAs such as microRNAs (miRNAs) and circular RNAs (circRNAs) have been reported to contribute to the pathogenesis of AD. We found an age-dependent elevation of miR-138 in APP/PS1 (presenilin-1) mice. MiR-138 inhibited the expression of ADAM10 [a disintegrin and metalloproteinase domain-containing protein 10], promoted amyloid beta (Aβ) production, and induced synaptic and learning/memory deficits in APP/PS1 mice, while its suppression alleviated the AD-like phenotype in these mice. Overexpression of sirtuin 1 (Sirt1), a target of miR-138, ameliorated the miR-138-induced inhibition of ADAM10 and elevation of Aβ in vitro. The circRNA HDAC9 (circHDAC9) was predicted to contain a miR-138 binding site in several databases. Its expression was inversely correlated with miR-138 in both Aβ-oligomer-treated N2a cells and APP/PS1 mice, and it co-localized with miR-138 in the cytoplasm of N2a cells. CircHDAC9 acted as a miR-138 sponge, decreasing miR-138 expression, and reversing the Sirt1 suppression and excessive Aβ production induced by miR-138 in vitro. Moreover, circHDAC9 was decreased in the serum of both AD patients and individuals with mild cognitive impairment. These results suggest that the circHDAC9/miR-138/Sirt1 pathway mediates synaptic function and APP processing in AD, providing a potential therapeutic target for its treatment.

Cyanidin-3-glucoside induces mesenchymal to epithelial transition via activating Sirt1 expression in triple negative breast cancer cells

Triple-negative breast cancer (TNBC) is a heterogeneous group of breast cancer with one common feature: distinctly metastatic nature with higher rate of relapse and shorter survival compared with other subtypes of breast cancer. The epithelial to mesenchymal transition (EMT) is highly associated with cancer metastasis. Cyanidin-3-glucoside (C3G), the most abundant anthocyanin pigment enriched in fresh fruits and vegetables, showed ideal anti-oxidant property. C3G could also inhibit certain malignant behaviors of cancer cells, however, whether repression of EMT was involved in its anti-cancer especially TNBC effect remains unknown. Herein, we report that C3G decreases the migratory and invasive nature of TNBC lines MDA-MB-231 and BT-549. Mechanistically, C3G induces reversion of EMT characterized by phenotype modulation with increased epithelial marker E-ca and ZO-1, decreased mesenchymal marker Vimentin, N-ca and EMT-associated transcription factors Snail1, Snail2. NF-κB is pivotal for EMT and Sirt1 is a NF-κB inhibitor. We show that NF-κB is attenuated and Sirt1 is induced by C3G in TNBC, respectively. And later evidence demonstrates that abrogation of Sirt1 with small interfering RNA transfection abolished NF-κB inhibition and EMT reversion by C3G. Subsequently, we show that microRNA-138(miR-138) represses Sirt1 via mRNA translation inhibition and is inhibited by C3G. Moreover, miR-138 repression is involved in Sirt1 re-activation and migratory and invasive inhibition of TNBC by C3G. Taken together, we supplied more evidence to the anti-breast cancer mechanisms of C3G.

LINC01016 promotes the malignant phenotype of endometrial cancer cells by regulating the miR-302a-3p/miR-3130-3p/NFYA/SATB1 axis

Long noncoding RNAs (lncRNAs) have been implicated in tumorigenesis and cancer progression and are tightly associated with the phenotypes of numerous cancers. However, the functional roles underlying these effects are unknown. The expression levels of LINC01016, miR-302a-3p, miR-3130-3p, NFYA, and SATB1 were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) in 33 endometrial cancer tissues and 20 normal tissues. Bioinformatics analyses, luciferase reporter analyses, chromatin immunoprecipitation (ChIP) assays, and qRT-PCR assays were performed to verify potential binding sites. The qRT-PCR and western blot were used to identify the regulatory mechanisms of LINC01016 in cell biological behavior, which were also examined by cell counting kit -8 (CCK-8), 5-ethynyl-2′-deoxyuridine (EdU) assays, flow cytometry, wound healing assays, and transwell assays. LINC01016 was substantially upregulated in endometrial cancer tissues, and LINC01016 silencing abolished the malignant behavior of endometrial cancer cells. LINC01016 positively rescued the downstream gene nuclear factor YA (NFYA) by competitively “sponging” miR-302a-3p and miR-3130-3p. In turn, these two miRNAs could inhibit LINC01016 transcription, thus forming two reciprocal repression cycles, which influenced the biological behavior of endometrial cancer cells. MiR-302a-3p and miR-3130-3p could specifically bind with the 3′-UTR regions of NFYA, and NFYA could upregulate the expression of special AT-rich sequence-binding protein 1 (SATB1) as a transcriptional factor. This study was the first to show that the LINC01016–miR-302a-3p/miR-3130-3p/NFYA/SATB1 axis played a crucial role in the occurrence of endometrial cancer. These findings may provide relevant insights into the diagnosis and therapy of endometrial cancer.

miR-149 promotes human osteocarcinoma progression via targeting bone morphogenetic protein 9 (BMP9)

OBJECTIVES

To investigate the roles of miR-149 in the progression of human osteosarcoma (OS).

RESULTS

miR-149 level was upregulated in tissues from OS patients more than in normal subjects. Cell proliferation and apoptosis assays revealed that miR-149 increased cell proliferation and inhibited cell apoptosis in OS cell line (MG63). An increase of Bcl-2 gene expression and a decrease of cleaved-caspase-3, and cleaved-PARP expression were observed in MG63 cells with transfection of miR-149. Additionally, bone morphogenetic protein 9 (BMP9) was identified as a target of miR-149 in MG63 cells, and BMP9 expression was negatively correlated with miR149 level in OS clinical samples. Co-overexpression of BMP9 with miR-149 in MG63 cells prohibited miR-149-mediated promotive effects on OS progression. Importantly, overexpression of miR-149 conferred chemoresistance in MG63 cells.

CONCLUSIONS

miR-149 promotes OS progression via targeting BMP9.