miRNA-105-5p Regulates the Histone Deacetylase HDAC2 through FOXG1 to Affect the Malignant Biological Behavior of Triple-negative Breast Cancer Cells.

BACKGROUND: Triple-negative breast cancer (TNBC) is a specific subtype of breast cancer (BC). Some potential molecular targets have been identified, and miR-105-5p was found to be abnormally expressed in TNBC tissues. OBJECTIVE: The objective of this study was to probe the effect of miR-105-5p on TNBC via FOXG1/HDAC2-mediated acetylation. METHODS: An animal model of TNBC was established by injecting BC cells into the axillary area of nude mice. The levels of miR-105-5p, FOXG1, HDAC2, Bcl-2, Bax, and Ki67 were detected via RT‒qPCR, Western blotting and immunohistochemistry. Flow cytometry, CCK-8, Transwell and colony formation assays were used to measure apoptosis, proliferation and migration, respectively. Total histone acetylation levels were measured by ELISA. The binding of FOXG1 to HDAC2 was detected by co-immunoprecipitation. The binding relationship between miR-105-5p and FOXG1 was verified using a dual-luciferase reporter gene assay. RESULTS: In this study, miR-105-5p and HDAC2 were highly expressed in the MDA-MB-231 and BT-549 BC cell lines, whereas FOXG1 was expressed at low levels. The inhibition of miR-105-5p inhibited the proliferation and migration of MDA-MB-231 and BT-549 cells and promoted their apoptosis. Bioinformatics analysis revealed that miR-105-5p and FOXG1 had a negative targeting regulatory relationship. FOXG1 overexpression had a similar effect on cancer cells as the inhibition of miR-105-5p. Moreover, experiments revealed that FOXG1 and HDAC2 could bind to each other and that HDAC2 overexpression or treatment with the histone acetyltransferase inhibitor Garcinol weakened the effect of FOXG1 overexpression. In addition, FOXG1 knockdown inhibited the effect of the miR-105-5p inhibitor, while Garcinol treatment further enhanced the effect of FOXG1 knockdown, inhibited histone acetylation, promoted the proliferation and migration of cancer cells, and inhibited apoptosis. Moreover, the in vivo results confirmed the in vitro results. CONCLUSION: miR-105-5p promotes HDAC2 expression by reducing FOXG1, inhibits histone acetylation, and aggravates the malignant biological behavior of TNBC cells.

Circular RNA circMRPS35 represses malignant progression in osteosarcoma cells via targeting miR-105-5p/FOXO1.

Osteosarcoma is a highly metastatic, aggressive bone cancer that occurs in children and young adults worldwide. Circular RNAs (circRNAs) are crucial molecules for osteosarcoma progression. In this study, we aimed to investigate the impact of circMRPS35 overexpression and its interaction with FOXO1 via evaluating apoptosis, cell cycle, and bioinformatic analyses on the malignant development of osteosarcoma in MG63 and MNNG/HOS cells. We found that circMRPS35 overexpression reduced osteosarcoma cell viability and inhibited tumor growth in vivo. It increased the apoptosis rate and induced cell cycle arrest in osteosarcoma cells. We identified a potential interaction between circMRPS35 and FOXO1 with miR-105-5p using bioinformatics analysis. Overexpression of circMRPS35 decreased miR-105-5p expression, whereas miR-105-5p mimic treatment increased its expression. This mimic also suppressed the luciferase activity of circMRPS35 and FOXO1 and reduced FOXO1 expression. Overexpression of circMRPS35 elevated FOXO1 protein levels, but this effect was reversed by co-treatment with the miR-105-5p mimic. We demonstrated that inhibiting miR-105-5p decreased viability and induced apoptosis. Overexpression of FOXO1 or treatment with a miR-105-5p inhibitor could counteract the effects of circMRPS35 on viability and apoptosis in osteosarcoma cells. Therefore, we concluded that circMRPS35 suppressed the malignant progression of osteosarcoma via targeting the miR-105-5p/FOXO1 axis.

Does the miR-105-1-Kisspeptin Axis Promote Ovarian Cell Functions?

The objective of this study was to elucidate the intricate interplay among miR-105-1, kisspeptin, and their synergistic influence on basic ovarian granulosa cell functions. The effects of miR-105-1 mimics or miR-105-1 inhibitor, kisspeptin (0, 1, and 10 ng/ml), and its combinations with miR-105-1 mimics on porcine granulosa cells were assessed. The expression levels of miR-105-1, viability, proliferation (accumulation of PCNA, cyclin B1, XTT-, and BrdU-positive cells), apoptosis (accumulation of bcl-2, bax, caspase 3, p53, TUNEL-positive cells), proportion of kisspeptin-positive cells, and the release of steroid hormones and IGF-I were analyzed. Transfection of cells with miR-105-1 mimics promoted cell viability and proliferation, the occurrence of kisspeptin, and the release of progesterone and IGF-I; in contrast, miR-105-1 mimics inhibited apoptosis and estradiol output. MiR-105-1 inhibitor had the opposite effect. Kisspeptin amplified the expression of miR-105-1, cell viability, proliferation, steroid hormones, and IGF-I release and reduced apoptosis. Furthermore, the collaborative action of miR-105-1 mimics and kisspeptin revealed a synergistic relationship wherein miR-105-1 mimics predominantly supported the actions of kisspeptin, while kisspeptin exhibited a dual role in modulating the effects of miR-105-1 mimics. These findings not only affirm the pivotal role of kisspeptin in regulating basic ovarian cell functions but also represent the inaugural evidence underscoring the significance of miR-105-1 in this regulatory framework. Additionally, our results show the ability of kisspeptin to promote miR-105-1 expression and the ability of miR-105-1 to promote the occurrence and effects of kisspeptin and, therefore, indicate the existence of the self-stimulating kisspeptin-miR-105-1 axis.

Possible Involvement of Long Non-Coding RNAs GNAS-AS1 and MIR205HG in the Modulation of 5-Fluorouracil Chemosensitivity in Colon Cancer Cells through Increased Extracellular Release of Exosomes.

A growing number of studies have suggested the involvement of long non-coding RNAs as the key players in not just the initiation and progression of the tumor microenvironment, but also in chemotherapy tolerance. In the present study, generated 5-FU-resistant SW480/DR cells were analyzed via cDNA microarray for its aberrant lncRNAs and mRNAs expression in comparison with the 5-FU-susceptible SW480/DS cells. Among the 126 lncRNAs described, lncRNAs GNAS-AS1, MIR205HG, and LOC102723721 have been identified to be significantly upregulated, while lncRNs lnc-RP11-597K23.2.1-2, LOC100507639, and CCDC144NL-AS1 have been found to be significantly downregulated. In the meantime, bioinformatic analysis through gene ontology studies of aberrantly expressed mRNAs revealed "regulated exocytosis", among others, as the biological process most impacted in SW480/DR cells. To investigate, exosome purification was then carried out and its characterization were validated via transmission electron microscopy and nanoparticle tracking analysis. Interestingly, it was determined that the 5-FU-resistant SW480/DR cells secretes significantly higher concentration of extracellular vesicles, particularly, exosomes when compared to the 5-FU-susceptible SW480/DS cells. Based on the lncRNA-mRNA interaction network analysis generated, lncRNA GNAS-AS1 and MIR205HG have been identified to be potentially involved in the incidence of 5-FU resistance in SW480 colon cancer cells through promoting increased release of exosomes into the intercellular matrix. Our study hopes not only to provide insights on the list of involved candidate lncRNAs, but also to elucidate the role exosomes play in the initiation and development of 5-FU chemotherapy resistance in colon cancer cells.

Exosomal miR-105-5p derived from bladder cancer stem cells targets for GPR12 to promote the malignancy of bladder cancer.

Bladder cancer stem cells (BCSCs) are considered as the root cause of BC initiation and recurrence, and exosomes derived from BCSCs (CSCs-exo) are the vital tool for establishing a stable tumor microenvironment. miR-105-5p has been revealed to promote tumor growth in a variety of cancers, but the effects on BC are still not included.Characteristics of CSCs-exo were examined by transmission electron microscope and nanoparticle tracking analysis. PKH67 dye was used to observe the cellular uptake of exosomes. Cell viability, migration and invasion were detected by CCK-8, wound healing and transwell invasion assays, respectively. The interaction between miR-105-5p and GPR12 was verified by luciferase activity assay. Xenografts were induced in the nude mice, and H&E staining method was applied to analyze the histological changes of xenografts. CSCs-exo efficiently promoted BC cell viability, migration and invasion. miR-105-5p was highly expressed in CSCs and CSCs-exo treatment significantly upregulated the expression of miR-105-5p in BC cells.GPR12 was subsequently verified to be the target gene of miR-105-5p, and overexpression of GPR12 abrogated the effects of miR-105-5p on BC cell growth and metastasis. Reversely, the anti-tumor function of miR-105-5p antagomir was observed in the xenograft mice.CSCs aggravated the malignancy of BC partly through transmitting exosomal miR-105-5p to BC cells to inhibit the expression of GPR12, which developed a novel aspect for CSC-targeted therapies.

LncRNA FAM138B inhibits the progression of non-small cell lung cancer through miR-105-5p.

As a type of lung cancer, non-small cell lung cancer (NSCLC) has the characteristics of high mortality and high recurrence rate, which poses a great threat to human life and health. Due to the high risk of surgical treatment and the slow recovery of wounds, non-coding RNAs, especially lncRNAs are used as new potential clinical prognostic markers to prevent and treat cancer in advance. This study aims to explore the role of FAM138B in NSCLC and its possibility as a prognostic biomarker. Real-timequantitative polymerase chain reaction (RT-qPCR) was used to detect the expression and overexpression level of lncRNA FAM138B (FAM138B) in cells and tissues. The CCK-8, Transwell migration and invasion methods were performed to observe the cell transfection.The interaction between FAM138B and miR-105-5p was predicted by the bioinformatics tool starBase v2.0, and verified by the luciferase reporter gene experiment. Kaplan-Meier and Cox regression analyses were used to determine the prognostic significance of FAM138B in NSCLC. The expression of FAM138B is down-regulated in NSCLC cells and tissues. Overexpression of FAM138B can inhibit the expression level of miR-105-5p in NSCLC cells, and the ability of NSCLC cells to proliferate, migrate and invade is downregulated. FAM138B targets miR-105-5p, and there is a negative correlation between FAM138B and miR-105-5p. It is confirmed that FAM138B inhibits the progression of NSCLC by targeting miR-105-5p and can be a potential prognostic biomarker for NSCLC.

The LINC00261/MiR105-5p/SELL axis is involved in dysfunction of B cell and is associated with overall survival in hepatocellular carcinoma.

Background: Previous studies have been reported the immune dysfunction of various live tissues. However, the potential molecular mechanism of post-transcriptional regulation of immune related genes in hepatocellular carcinoma (HCC) is still not clear. We tried to identify crucial immune related biomarkers associated with HCC patients' outcomes and to reveal the transcriptional regulation. Method: The fractions of 22 immune cells in tumor and adjacent tissues were estimated by CIBERSORT. Kruskal-Wallis test and differentially expressed analyzes were used for comparative studies. Cox proportional hazard regression model, Kaplan-Meier estimates and Log-rank test were used for survival analyses. Results: From The Cancer Genome Atlas (TCGA), the gene, lncRNA and miRNA expression profiles of 379 HCC samples with clinical information were used for comparative studies. Eleven adaptive and innate immune cell types were significantly altered in HCC samples, including B cell memory, regulatory T cells and follicular helper T cells. Differentially expressed competing endogenous RNA (ceRNA) network associated with patients' overall survival was identified. Then, the novel pathway, including LINC00261, MiR105-5p and selectin L(SELL) was found and may be potential novel biomarkers for patients' outcomes and immunotherapy. Furthermore, SELL was significantly positively correlated (correlation coefficients: 0.47-0.69) with 12 known gene signatures of immunotherapy except for programmed cell death 1 (PDCD1). Conclusions: Our findings could provide insights into the selection of novel LINC00261/MiR105-5p/SELL pathway which is associated with overall survival and may impact on efficacy of immunotherapy in HCC.

miR-873 and miR-105-2 May Affect the Tumour Microenvironment and are Potential Biomarkers for Lung Adenocarcinoma.

Background: Lung adenocarcinoma (LUAD) accounts for approximately 40% of all lung cancer cases. The tumour microenvironment (TME) and microRNAs affect the occurrence, metastasis, recurrence and treatment of tumours. However, the role of microRNAs in the TME and LUAD still needs to be further investigated. Methods: RNA-seq and microRNA-seq data of LUAD and NSCLC samples were downloaded from the TCGA and GEO database. The immune and stromal components in the TME and the abundance of tumour-infiltrating immune cells (TICs) were calculated by the ESTIMATE and CIBERSORT algorithms, respectively. The differentially expressed microRNAs (DEMs) between different StromalScore and ImmuneScore groups were screened out by the edgeR package. Bioinformatics analysis was performed to screen out important DEMs and explore their functional effect. Results: Our results revealed that a low StromalScore, ImmuneScore and ESTIMATEScore led to poor prognosis of LUAD. Then, 62 DEMs were screened out as downregulated in both the high StromalScore and ImmuneScore groups. Among these DEMs, elevated expression levels of miR-873, miR-105-2 and miR-516a-2 significantly shortened the survival time of LUAD patients. Subsequent analysis revealed that the expression levels of miR-873 and miR-105-2 were increased significantly in tumour tissues. The expression patterns of these 2 microRNAs were confirmed by GSE102286, implying the important roles of these 2 microRNAs in LUAD. Further analysis showed that miR-873 and miR-105-2 were mainly involved in immune-related pathways and that high expression levels of miR-873 and miR-105-2 decreased the abundance of monocytes and resting dendritic cells in the TME. Conclusion: Although further exploration is still needed, our results revealed that miR-873 and miR-105-2 were closely related to the TME and affected the prognosis of LUAD by altering the abundance of TICs.

Extracellular Vesicle-Derived miR-105-5p Promotes Malignant Phenotypes of Esophageal Squamous Cell Carcinoma by Targeting SPARCL1 via FAK/AKT Signaling Pathway.

Objective: Esophageal squamous cell carcinoma (ESCC) presents high morbidity and mortality. It was demonstrated that blood-derived vesicles can facilitate ESCC development and transmit regulating signals. However, the molecular mechanism of vesicle miRNA secreted by tumor cells affecting ESCC progression has not been explored. Methods: The mRNA-related signaling pathways and differentially expressed genes were screened out in TCGA dataset. The levels of miRNA-105-5p and SPARCL1 were determined by qRT-PCR. Protein level determination was processed using Western blot. The interaction between the two genes was verified with the dual-luciferase method. A transmission electron microscope was utilized to further identify extracellular vesicles (EVs), and co-culture assay was performed to validate the intake of EVs. In vitro experiments were conducted to evaluate cell function changes in ESCC. A mice tumor formation experiment was carried out to observe tumor growth in vivo. Results: MiRNA-105-5p expression was increased in ESCC, while SPARCL1 was less expressed. MiRNA-105-5p facilitated cell behaviors in ESCC through targeting SPARCL1 and regulating the focal adhesion kinase (FAK)/Akt signaling pathway. Blood-derived external vesicles containing miRNA-105-5p and EVs could be internalized by ESCC cells. Then, miRNA-105-5p could be transferred to ESCC cells to foster tumorigenesis as well as cell behaviors. Conclusion: EV-carried miRNA-105-5p entered ESCC cells and promoted tumor-relevant functions by mediating SPARCL1 and the FAK/Akt signaling pathway, which indicated that the treatment of ESCC via serum EVs might be a novel therapy and that miRNA-105-5p can be a molecular target for ESCC therapy.

LncRNA LINC00184 promotes docetaxel resistance and immune escape via miR-105-5p/PD-L1 axis in prostate cancer.

BACKGROUND: Docetaxel (DTX) resistance is a common factor in metastatic prostate cancer (PC) chemotherapy that leads to treatment failure. Because lncRNA is involved in a variety of regulatory processes in tumor progression, this study aimed to explore the function and mechanism of LINC00184 in docetaxel resistance of PC. METHODS: Two PC cell lines and their docetaxel resistant cell lines (DU145/DTX and PC3/DTX) were used. The expression of LINC00184 in both cell lines and PC patient samples were evaluated. SiRNA knocking down was used to test the function of LINC00184 in proliferation and colony formation. Interaction between LINC00184 and its target miR-105-5p, as well as miR-105-5p and PD-L1 was checked by luciferase reporter assay and RNA pull-down assay. PC cell line and CD8 + T cell co-culture system was established, miR-105-5p inhibitor was co-transfected with LINC00184 siRNA to investigate the underline mechanism. RESULTS: LINC00184 was found to be associated with docetaxel resistance and adverse prognosis of prostate cancer. It regulated docetaxel resistance and T-cell-mediated immune response in prostate cancer cells. LINC00184 was induced by adsorption of miR-105-5p and negatively regulated it, subsequently inhibited the expression level of PD-L1. CONCLUSIONS: LINC00184 promoted docetaxel resistance and immune escape in prostate cancer cells by adsorption of miR-105-5p, resulted in upregulation of the expression of PD-L1. LINC00184 could possibly be considered as a potential target for treatment in prostate cancer patients with docetaxel-resistance.

lncRNA MCF2L-AS1/miR-105/ IL-1ß Axis Regulates Colorectal Cancer Cell Oxaliplatin Resistance.

BACKGROUND: Interactions between non-coding RNAs and mRNAs have been shown to play key roles in colorectal cancer (CRC) resistance to chemotherapeutic drugs, but the regulatory network of these ncRNA/mRNA interactions in the context of CRC cell resistance to oxaliplatin has yet to be fully defined. METHODS: MCF2L-AS1, miR-105, and IL-1ß expression levels were measured in cells and serum samples via qPCR, while ELISAs were additionally used to quantify IL-1ß levels in these samples. Interactions between MCF2L-AS1, miR-105, and IL-1ß were detected through pull-down, RNA immunoprecipitation, and luciferase reporter assays. Cellular viability and OXA IC50 values were established through MTT assays, while in vivo OXA resistance was assessed using a tumor xenograft model system. RESULTS: MCF2L-AS1 levels were significantly elevated in CRC patients that did not respond to chemotherapy and in CRC/OXA cells relative to responders and chemosensitive CRC cells. From a mechanistic perspective, miR-105 was identified as a MCF2L-AS1 target, with this miRNA, in turn, suppressing the expression of IL-1ß. Knocking down MCF2L-AS1 or overexpressing miR-105 was sufficient to alleviate CRC/OXA cell chemoresistance, while overexpressing IL-1ß reversed this effect. CONCLUSION: The MCF2L-AS1/miR-105/IL-1ß regulatory axis regulates the resistance of CRC cells to OXA treatment.

LncRNA MCF2L-AS1 aggravates the malignant development of colorectal cancer via targeting miR-105-5p/RAB22A axis.

BACKGROUND: Colorectal cancer (CRC) represents one of the major malignant cancers in the world. It has been demonstrated that long non-coding RNAs (lncRNAs) can cause great influences on various human cancers. Though MCF.2 cell line derived transforming sequence like antisense RNA 1 (MCF2L-AS1) and its carcinogenic effect in CRC has been elucidated by several previous researches, the underlying mechanism remains unknown. AIM: We aimed at exploring the function and regulatory mechanism of MCF2L-AS1 in CRC. METHODS: MCF2L-AS1 expression in CRC cells was tested via RT-qPCR assay. The effects of MCF2L-AS1 on the biological properties of CRC cells were testified through functional experiments. The molecular mechanism of MCF2L-AS1 was verified through mechanism experiments. RESULTS: MCF2L-AS1 was highly expressed in CRC cells, and it could enhance the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) process of CRC cells. MiR-105-5p was sponged by MCF2L-AS1 in CRC cells and Ras-related protein Rab-22A (RAB22A) was verified to be the downstream target of miR-105-5p. It was verified through rescue assays that RAB22A overexpression or miR-105-5p silencing could reverse the repressive impact of MCF2L-AS1 silencing on CRC progression. CONCLUSION: MCF2L-AS1 accelerated the malignant development of CRC cells by targeting the miR-105-5p/RAB22A axis.

Long noncoding RNA HOXC-AS3 enhances the progression of cervical cancer via activating ErbB signaling pathway.

Emerging evidence reveals that long noncoding RNAs (lncRNAs) contribute to human tumorigenesis. Nevertheless, the function of HOXC cluster antisense RNA 3 (HOXC-AS3) in human cervical cancer (CC) remains largely unknown. The levels of HOXC-AS3, miR-105-5p and SOS1 in CC tissues and cells were monitored by reverse transcription-polymerase chain reaction (RT-PCR) and western blot (WB). Gain- and loss-of-function experiments were conducted to verify the function of HOXC-AS3 and miR-105-5p in CC cells. Meanwhile, cell proliferation, apoptosis, migration and invasion were examined by the cell counting kit-8 (CCK8) experiment, colony formation assay, flow cytometry and Transwell assay. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were carried out to test the regulatory interaction of HOXC-AS3, miR-105-5p and SOS1. In addition, in vivo experiment was performed to certain the role of HOXC-AS3 in tumorigenesis of CC. HOXC-AS3 was overexpressed in CC tissues (vs. adjacent normal tissues) and CC cells. Besides, the higher HOXC-AS3 profile was associated with the poorer clinical prognosis of CC patients. Overexpression of HOXC-AS3 promoted cell growth, migration and invasion, hampered apoptosis, whereas knocking down HOXC-AS3 exhibited the reverse effects. MiR-105-5p was a downstream target of HOXC-AS3, and it mediated the HOXC-AS3-induced oncogenic effects. Mechanistically, the bioinformatic analysis illustrated that SOS1 was targeted by miR-105-5p. Up-regulating SOS1 heightened the growth, migration and invasion of CC cells by enhancing the ErbB signaling pathway, which was reversed by miR-105-5p. Up-regulated HOXC-AS3 aggravates CC by promoting SOS1 expression via targeting miR-105-5p.

Propofol induces hepatocellular carcinoma cell apoptosis via regulating miR-105/JAK2/STAT3 axis.

BACKGROUND: Hepatocellular carcinoma (HCC) is a type of malignancy with high mortality. It has been reported Propofol could modulate the tumorigenesis of liver cancer; however, the mechanism by which Propofol regulates the development of HCC is still not clear. METHODS: CCK8 assay was applied to test the cell viability. Flow cytometry and TUNEL staining were applied to detect the cell apoptosis. Meanwhile, dual luciferase reporter assay was performed to investigate the association between miR-105 and JAK2. In addition, RNA and protein levels were investigated by qRT-PCR and western blot, respectively. RESULTS: Propofol significantly suppressed the proliferation of HCC cells via inducing the apoptosis. Consistently, miR-105 upregulation inhibited the proliferation of HCC cells, while downregulation of miR-105 reversed Propofol-induced HCC cell apoptosis. Meanwhile, JAK2 was found to be the direct target of miR-105. Furthermore, Propofol could inactivate JAK2/STAT3 signaling via upregulation of miR-105. CONCLUSION: Propofol significantly attenuated HCC tumorigenesis via mediation of miR-105/JAK2/STAT3 axis. Thereby, Propofol might act as a new agent for the treatment of HCC.

Long non-coding RNA CYTOR regulates proliferation and metastasis of colon cancer cells through regulating miRNA-105/PTEN axis.

Colon cancer is a common malignancy, and its incidence and mortality have been increasing in recent years. This study aims to explore the regulation of long non-coding RNA CYTOR on proliferation and metastasis of colon cancer cells through miRNA-105/PTEN axis. Real-time quantitative PCR (qRT-PCR) disclosed that expression of CYTOR was significantly decreased in colon cancer tissues, compared with that of adjacent normal tissues, while miRNA-105 was significantly increased. Correlation study found that CYTOR was negatively correlated with miR-105. The proliferation, migration, and invasion rates of the LoVo cells with highly expressed CYTOR were significantly slower. miR-105 mimic could suppress the decrease in proliferation, migration, and invasion rates of colon cancer cells caused by overexpression of CYTOR. Additionally, the proliferation, migration, and invasion rates of the LoVo cells in miR-105 inhibition group were significantly slower. The Starbase database predicted the targeting of miR-105 by CYTOR, and qRT-PCR and dual luciferase reporter gene method were used to verify the targeting relationship of CYTOR and miRNA-105/PTEN axis. In conclusion, CYTOR can inhibit the proliferation and metastasis of colon cancer cells through targeted inhibition of the miR-105/PTEN axis.

Induced pluripotent stem cell-derived mesenchymal stem cells deliver exogenous miR-105-5p via small extracellular vesicles to rejuvenate senescent nucleus pulposus cells and attenuate intervertebral disc degeneration.

BACKGROUND: Mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) have emerged as a promising new therapeutic strategy for intervertebral disc degeneration (IVDD). However, the drawbacks of MSCs, including their invasive access, the donor age, and their limited proliferative capacity, hinder the quantity and quality of MSC-sEVs. Induced pluripotent stem cell-derived MSCs (iMSCs) provide an indefinite source of MSCs with well-defined phenotype and function. This study aimed to investigate the therapeutic effect of sEVs derived from iMSC (iMSC-sEVs) on IVDD and explore the underlying molecular mechanisms. METHODS: IVDD models were established by puncturing discs from the tails of rats. Then, iMSC-sEVs were injected into the punctured discs. The degeneration of punctured discs was assessed using MRI and HE and immunofluorescence staining. The age-related phenotypes were used to determine the effects of iMSC-sEVs on senescent nucleus pulposus cells (NPCs) in vitro. Western blotting was used to detect the expression of Sirt6. miRNA sequencing analysis was used to find miRNAs that potentially mediate the activation of Sirt6. RESULTS: After intradiscally injecting iMSC-sEVs, NPC senescence and IVDD were significantly improved. iMSC-sEVs could rejuvenate senescent NPCs and restore the age-related function by activating the Sirt6 pathway in vitro. Further, microRNA sequence analysis showed that iMSC-sEVs were highly enriched in miR-105-5p, which played a pivotal role in the iMSC-sEV-mediated therapeutic effect by downregulating the level of the cAMP-specific hydrolase PDE4D and could lead to Sirt6 activation. CONCLUSION: iMSC-sEVs could rejuvenate the senescence of NPCs and attenuate the development of IVDD. iMSC-sEVs exerted their anti-ageing effects by delivering miR-105-5p to senescent NPCs and activating the Sirt6 pathway. Our findings indicate that iMSCs are a promising MSC candidate for obtaining sEVs on a large scale, while avoiding several defects related to the present applications of MSCs, and that iMSC-sEVs could be a novel cell-free therapeutic tool for the treatment of IVDD.

MiR-105 enhances osteogenic differentiation of hADSCs via the targeted regulation of SOX9.

OBJECTIVE: To investigate whether miR-105 can regulate the osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADSCs) by targeting SOX9. METHODS: The hADSCs were grouped for subsequent transfection and induction of osteogenic differentiation as follows: control, miR-NC, miR-105 mimics, miR-105 inhibitors, SOX9, SOX9 siRNA, miR-105 mimics + SOX9 and miR-105 inhibitors + SOX9 siRNA groups. Next, hADSCs were stained for alkaline phosphatase (ALP), and Alizarin Red S staining (ARS) was performed. Osteogenic differentiation-related genes and miR-105 expression were assessed by qRT-PCR, while SOX9 protein expression was determined by Western blotting. RESULTS: MiR-105 expression was increased and SOX9 protein expression was decreased during the osteogenic differentiation of hADSCs. A dual-luciferase reporter assay confirmed SOX9 to be a target gene of miR-105. Compared with the control group, the miR-105 mimics and SOX9 siRNA groups had elevated BMP2, OPN, OCN, BSP, Osx and Runx2 mRNA expression with reduced SOX9 expression, as well as increased ARS intensity and ALP activity. After transfection of miR-105 inhibitors/SOX9 into hADSCs, the results were the opposite. Overexpressing SOX9 reversed the effect of miR-105 in promoting the osteogenic differentiation of hADSCs. CONCLUSION: MiR-105 could target SOX9 to improve the expression of osteogenic differentiation genes and thus enhance the osteogenic differentiation of hADSCs.

Role of hsa­miR­105 during the pathogenesis of paclitaxel resistance and its clinical implication in ovarian cancer.

More than 70% of patients with epithelial ovarian cancer (EOC), one of the leading cause of gynecological cancer­related deaths worldwide, are diagnosed at an advanced stage of the disease. Currently, the mainstay for treatment of advanced EOC is tumor debulking surgery followed by combined platinum­ and paclitaxel (PTX)­based chemotherapy. However, most patients eventually develop chemoresistance, which remains a major obstacle to successful treatment. Herein, by using clinical specimens and experimentally induced cell models, we found that the expression levels of hsa­miR­105 were significantly decreased in PTX­resistant EOC tissues and cell lines. Follow­up functional experiments demonstrated that repression of hsa­miR­105 conferred resistance to paclitaxel in EOC cells, whereas restoration of hsa­miR­105 expression in situ via intratumoral injection of hsa­miR­105 micrON™ agomir potentiated in vivo sensitivity to PTX and thereafter significantly inhibited tumor growth in a PTX­challenged xenograft model. Mechanistically, hsa­miR­105 exerted its tumor suppressor function by directly inhibiting the zinc and ring finger 2 (ZNRF2) signaling pathway. Importantly, aberrant expression of hsa­miR­105 in both tumor and circulating samples predicted a poor post­chemotherapy prognosis in EOC patients. These findings collectively suggest that hsa­miR­105 may act as a potent tumor suppressor miRNA during the progression of EOC, likely affecting cell proliferation, invasiveness and chemosensitivity to PTX, and functioning at least in part via inhibition of ZNRF2 signaling. The stability and availability and ease in measurement of circulating hsa­miR­105 make it a valuable diagnostic/prognostic biomarker candidate for chemotherapy of EOC.

MiR-105-3p acts as an oncogene to promote the proliferation and metastasis of breast cancer cells by targeting GOLIM4.

BACKGROUND: Dysregulated miRNAs are involved in carcinogenesis of the breast and may be used as prognostic biomarkers and therapeutic targets during the cancer process. The purpose of this study was to explore the effect of miR-105-3p on the tumourigenicity of breast cancer and its underlying molecular mechanisms. METHODS: Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was applied to detect the expression of miR-105-3p in breast cancer tissues and cell lines. The impacts of miR-105-3p on the proliferation, migration, invasion and apoptosis of human breast cancer cells (MCF-7 and ZR-75-30) were evaluated by CCK-8 assays, Transwell chamber assays, TUNEL assays and western blot analyses. In addition, bioinformatics and luciferase reporter assays were used to determine the target genes of miR-105-3p. RESULTS: The expression of miR-105-3p was elevated in breast cancer tissues and increased with tumour severity. Downregulation of miR-105-3p could inhibit cell proliferation, suppress cell migration/invasion, and promote cell apoptosis in MCF-7 and ZR-75-30 cells. Furthermore, Golgi integral membrane protein 4 (GOLIM4) was identified as the direct target gene of miR-105-3p by bioinformatics and luciferase reporter assays. In addition, silencing GOLIM4 restored the anti-breast cancer effects induced by miR-105-3p downregulation. CONCLUSIONS: MiR-105-3p acts as an oncogene to promote the proliferation and metastasis of breast cancer cells by targeting GOLIM4, which provides a new target for the prevention and treatment of breast cancer.

Plasma miR-1247-5p, miR-301b-3p and miR-105-5p as potential biomarkers for early diagnosis of non-small cell lung cancer.

BACKGROUND: Accumulating evidence shows that microRNAs are aberrantly expressed and exert essential roles in the tumorigenesis and tumor progression of non-small cell lung cancer (NSCLC). METHODS: The plasma miRNAs from five healthy donors and four NSCLC patients were profiled by miRNA microarray. The differentially expressed miRNAs from 154 primary NSCLC patients and 146 healthy donors were subjected to RNA isolation and verified by quantitative PCR (qPCR). RESULTS: The miRNA microarray analysis revealed that 40 differential miRNAs between NSCLC patients and healthy donors were selected. We found that the plasma miR-1247-5p, miR-301b-3p and miR-105-5p levels of patients were significantly higher than those of healthy controls. The receiver operating characteristic curve (ROC) analyses revealed higher area under the ROC curve (AUC) values and higher sensitivity/specificity of carcinoembryonic antigen (CEA) in combination with miR-1247-5p, miR-301b-3p, or miR-105-5p were superior to that of CEA alone. CONCLUSIONS: High miR-1247-5p, miR-301b-3p and miR-105-5p expression have been demonstrated to accelerate tumorigenesis, and these three miRNAs in plasma act as novel biomarkers for the early diagnosis of NSCLC patients. KEY POINTS: Plasma miR-1247-5p, miR-301b-3p and miR-105-5p act as novel biomarkers for early NSCLC and NSCLC.