Downregulation of miR-133a-3p promotes prostate cancer bone metastasis via activating PI3K/AKT signaling

AKT in Bone Metastasis of Solid Tumors: A Comprehensive Review

Simple Summary

Bone metastasis is a frequent complication of solid tumors and leads to a reduced overall survival. Although much progress has been made in the field of tumor therapy in the last years, bone metastasis depicts a stage of the disease with a lack of appropriate therapeutical options. Hence, this review aims to present the role of AKT in bone metastasis of solid tumors to place the spotlight on AKT as a possible therapeutical approach for patients with bone metastases. Furthermore, we intended to discuss postulated underlying molecular mechanisms of the bone metastasis-promoting effect of AKT, especially in highly bone-metastatic breast, prostate, and lung cancer. To conclude, this review identified the AKT kinase as a potential therapeutical target in bone metastasis and revealed remaining questions, which need to be addressed in further research projects.

Abstract

Solid tumors, such as breast cancer and prostate cancer, often form bone metastases in the course of the disease. Patients with bone metastases frequently develop complications, such as pathological fractures or hypercalcemia and exhibit a reduced life expectancy. Thus, it is of vital importance to improve the treatment of bone metastases. A possible approach is to target signaling pathways, such as the PI3K/AKT pathway, which is frequently dysregulated in solid tumors. Therefore, we sought to review the role of the serine/threonine kinase AKT in bone metastasis. In general, activation of AKT signaling was shown to be associated with the formation of bone metastases from solid tumors. More precisely, AKT gets activated in tumor cells by a plethora of bone-derived growth factors and cytokines. Subsequently, AKT promotes the bone-metastatic capacities of tumor cells through distinct signaling pathways and secretion of bone cell-stimulating factors. Within the crosstalk between tumor and bone cells, also known as the vicious cycle, the stimulation of osteoblasts and osteoclasts also causes activation of AKT in these cells. As a consequence, bone metastasis is reduced after experimental inhibition of AKT. In summary, AKT signaling could be a promising therapeutical approach for patients with bone metastases of solid tumors.

miR-133a silencing rescues glucocorticoid-induced bone loss by regulating the MAPK/ERK signaling pathway

BACKGROUND

Dysfunction of mesenchymal stem cells (MSCs) is recognized as critical to the pathogenesis of glucocorticoid-induced osteoporosis (GIO), suggesting the potential of MSC-targeting interventions for this disorder. As the miR-133a has been shown to play an important role in bone metabolism, we hypothesized that miR-133a may also be involved in GIO.

METHODS

In the in vitro study, we examined the effect of miR-133a antagomir on DEX-treated MSCs, including proliferation, apoptosis, osteoblast, and adipocyte differentiation, then, we explored the mechanism of these effects of miR-133a silencing through measuring the phosphorylation of ERK1/2 and its regulator FGFR1 via western blot and qRT-PCR. In the in vivo study, we developed a GIO rat model by injecting methylprednisolone and modulated the miR-133a expression in the femur by intramedullary injection of the miR-133a antagomir, and then micro-CT analyses and histological staining of the femurs were used to investigate the effect of miR-133a silencing on bone loss of the GIO rats.

RESULTS

qRT-PCR analysis indicated that glucocorticoid induced high miR-133a expression in MSCs and animal models. The in vitro study showed that miR-133a antagomir significantly promoted cell proliferation, viability, and osteoblast differentiation and inhibited adipocyte differentiation in DEX-treated MSCs. Furthermore, the expression of p-ERK1/2 and FGFR1 in DEX-treated MSCs was also upregulated by miR-133a antagomir. Then we investigated the effect of miR-133a silencing on the bone architecture of GIO models, micro-CT analysis showed that miR-133a antagomir attenuated the loss of bone mass and improved the trabecular and cortical parameters induced by methylprednisolone. Histological study showed that miR-133a silencing simultaneously increased bone formation and decreased marrow fat accumulation in GIO rats.

CONCLUSIONS

Our findings suggested that miR-133a is strongly associated with GIO and similar disorders induced by glucocorticoids in MSCs. Silencing miR-133a resulted in positive effects on GC-treated MSCs and on bone loss in GIO animal models. Moreover, the FGFR1-MAPK/ERK signaling may be involved in the protective effect of miR-133a silencing.

Mechanisms for Modulating Anoikis Resistance in Cancer and the Relevance of Metabolic Reprogramming

The attachment of cells to the extracellular matrix (ECM) is the hallmark of structure–function stability and well-being. ECM detachment in localized tumors precedes abnormal dissemination of tumor cells culminating in metastasis. Programmed cell death (PCD) is activated during tumorigenesis to clear off ECM-detached cells through “anoikis.” However, cancer cells develop several mechanisms for abrogating anoikis, thus promoting their invasiveness and metastasis. Specific factors, such as growth proteins, pH, transcriptional signaling pathways, and oxidative stress, have been reported as drivers of anoikis resistance, thus enhancing cancer proliferation and metastasis. Recent studies highlighted the key contributions of metabolic pathways, enabling the cells to bypass anoikis. Therefore, understanding the mechanisms driving anoikis resistance could help to counteract tumor progression and prevent metastasis. This review elucidates the dynamics employed by cancer cells to impede anoikis, thus promoting proliferation, invasion, and metastasis. In addition, the authors have discussed other metabolic intermediates (especially amino acids and nucleotides) that are less explored, which could be crucial for anoikis resistance and metastasis.

MicroRNAs Possibly Involved in the Development of Bone Metastasis in Clear-Cell Renal Cell Carcinoma

Simple Summary

Bone metastases cause substantial morbidity and implicate worse clinical outcomes for clear-cell renal cell carcinoma patients. MicroRNAs are small RNA molecules that modulate gene translation and are involved in the development of cancer and metastasis. We identified six microRNAs that are potentially specifically involved in metastasis to bone, of which two seem protective and four implicate a higher risk. This aids further understanding of the process of metastasizing to bone. Furthermore, these microRNA hold potential for biomarkers or therapeutic targets.

Abstract

Bone metastasis in clear-cell renal cell carcinoma (ccRCC) leads to substantial morbidity through skeletal related adverse events and implicates worse clinical outcomes. MicroRNAs (miRNA) are small non-protein coding RNA molecules with important regulatory functions in cancer development and metastasis. In this retrospective analysis we present dysregulated miRNA in ccRCC, which are associated with bone metastasis. In particular, miR-23a-3p, miR-27a-3p, miR-20a-5p, and miR-335-3p specifically correlated with the earlier appearance of bone metastasis, compared to metastasis in other organs. In contrast, miR-30b-3p and miR-139-3p were correlated with less occurrence of bone metastasis. These miRNAs are potential biomarkers and attractive targets for miRNA inhibitors or mimics, which could lead to novel therapeutic possibilities for bone targeted treatment in metastatic ccRCC.

miRNAs as Therapeutic Tools and Biomarkers for Prostate Cancer

Prostate cancer (PCa) is the fifth cause of tumor-related deaths in man worldwide. Despite the considerable improvement in the clinical management of PCa, several limitations emerged both in the screening for early diagnosis and in the medical treatment. The use of prostate-specific antigen (PSA)-based screening resulted in patients’ overtreatment and the standard therapy of patients suffering from locally advanced/metastatic tumors (e.g., radical prostatectomy, radiotherapy, and androgen deprivation therapy) showed time-limited efficacy with patients undergoing progression toward the lethal metastatic castration-resistant PCa (mCRPC). Although valuable alternative therapeutic options have been recently proposed (e.g., docetaxel, cabazitaxel, abiraterone, enzalutamide, and sipuleucel-T), mCRPC remains incurable. Based on this background, there is an urgent need to identify new and more accurate prostate-specific biomarkers for PCa diagnosis and prognosis and to develop innovative medical approaches to counteract mCRPC. In this context, microRNA (miRNAs) emerged as potential biomarkers in prostate tissues and biological fluids and appeared to be promising therapeutic targets/tools for cancer therapy. Here we overview the recent literature and summarize the achievements of using miRNAs as biomarkers and therapeutic targets/tools for fighting PCa.

Inhibition of cancer cell-derived exosomal microRNA-183 suppresses cell growth and metastasis in prostate cancer by upregulating TPM1

Background

Emerging evidence continues to highlight the significant role of microRNAs (miRNAs) in the regulation of cancer growth and metastasis. Herein, the current study aimed to elucidate the role of exosomal miR-183 in prostate cancer development.

Methods

Initially, public microarray-based gene expression profiling of prostate cancer was employed to identify differentially expressed miRNAs. The putative target gene TPM1 of miR-183 was subsequently predicted, followed by the application of a luciferase reporter assay and examination of the expression patterns in prostate cancer patients and cell lines. The effects of miR-183 and TPM1 on processes such as cell proliferation, invasion and migration were evaluated using in vitro gain- and loss-of-function experiments. The effect of PC3 cells-derived exosomal miR-183 was validated in LNCaP cells. In vivo experiments were also performed to examine the effect of miR-183 on prostate tumor growth.

Results

High expression of miR-183 accompanied with low expression of TPM1 was detected in prostate cancer. Our data indicated that miR-183 could target and downregulate TPM1, with the overexpression of miR-183 and exosomal miR-183 found to promote cell proliferation, migration, and invasion in prostate cancer. Furthermore, the tumor-promoting effect of exosome-mediated delivery of miR-183 was subsequently confirmed in a tumor xenograft model.

Conclusions

Taken together, the key findings of our study demonstrate that prostate cancer cell-derived exosomal miR-183 enhance prostate cancer cell proliferation, invasion and migration via the downregulation of TPM1, highlighting a promising therapeutic target against prostate cancer.

MiRNA-145-5p expression and prospective molecular mechanisms in the metastasis of prostate cancer

The clinicopathological implication and prospective molecular mechanisms of miRNA-145-5p in the metastasis of prostate cancer (PCa) stand unclear. Herein, it is found that miRNA-145-5p expression was remarkably reduced in 131 cases of metastatic PCa than 1371 cases of localised ones, as the standardised mean differences (SMD) was -1.26 and the area under the curve (AUC) was 0.86, based on miRNA-chip and miRNA-sequencing datasets. The potential targets of miRNA-145-5p in metastatic PCa (n = 414) was achieved from the intersection of miRNA-145-5p transfected metastatic PCa cell line data, differential expression of metastatic PCa upregulated genes and online prediction databases. TOP2A was screened as one of the target hub genes by PPI network analysis, which was adversely related to miRNA-145-5p expression in both metastatic PCa (r = -0.504) and primary PCa (r = -0.281). Gene-chip and RNA-sequencing datasets, as well as IHC performed on clinical PCa samples, showed consistent upregulated expression of TOP2A mRNA and protein in PCa compared with non-PCa. The expression of TOP2A mRNA was also significantly higher in metastatic than localised PCa with the SMD being 1.72 and the AUC of sROC being 0.91. In summary, miRNA-145-5p may participate in PCa metastasis by binding TOP2A and be useful as a biomarker for the detection of metastatic PCa.

The emerging role of non-coding RNAs in the regulation of PI3K/AKT pathway in the carcinogenesis process

The PI3K/AKT pathway is an intracellular signaling pathway with an indispensable impact on cell cycle control. This pathway is functionally related with cell proliferation, cell survival, metabolism, and quiescence. The crucial role of this pathway in the development of cancer has offered this pathway as a target of novel anti-cancer treatments. Recent researches have demonstrated the role of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in controlling the PI3K/AKT pathway. Some miRNAs such as miR-155-5p, miR-328-3p, miR-125b-5p, miR-126, miR-331-3p and miR-16 inactivate this pathway, while miR-182, miR-106a, miR-193, miR-214, miR-106b, miR-93, miR-21 and miR-103/107 enhance activity of this pathway. Expression levels of PI3K/AKT-associated miRNAs could be used to envisage the survival of cancer patients. Numerous lncRNAs such as GAS5, FER1L4, LINC00628, PICART1, LOC101928316, ADAMTS9-AS2, SLC25A5-AS1, MEG3, AB073614 and SNHG6 interplay with this pathway. Identification of the impact of miRNAs and lncRNAs in the control of the activity of PI3K/AKT pathway would enhance the efficacy of targeted therapies against this pathway. Moreover, each of the mentioned miRNAs and lncRNAs could be used as a putative therapeutic candidate for the interfering with the carcinogenesis. In the current study, we review the role of miRNAs and lncRNAs in controlling the PI3K/AKT pathway and their contribution to carcinogenesis.

The Role of Noncoding RNAs in the Regulation of Anoikis and Anchorage-Independent Growth in Cancer

Cancer is a global health concern, and the prognosis of patients with cancer is associated with metastasis. Multistep processes are involved in cancer metastasis. Accumulating evidence has shown that cancer cells acquire the capacity of anoikis resistance and anchorage-independent cell growth, which are critical prerequisite features of metastatic cancer cells. Multiple cellular factors and events, such as apoptosis, survival factors, cell cycle, EMT, stemness, autophagy, and integrins influence the anoikis resistance and anchorage-independent cell growth in cancer. Noncoding RNAs (ncRNAs), such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are dysregulated in cancer. They regulate cellular signaling pathways and events, eventually contributing to cancer aggressiveness. This review presents the role of miRNAs and lncRNAs in modulating anoikis resistance and anchorage-independent cell growth. We also discuss the feasibility of ncRNA-based therapy and the natural features of ncRNAs that need to be contemplated for more beneficial therapeutic strategies against cancer.

Long Non-Coding RNA MAPK8IP1P2 Inhibits Lymphatic Metastasis of Thyroid Cancer by Activating Hippo Signaling via Sponging miR-146b-3p

The principal issue derived from thyroid cancer is its high propensity to metastasize to the lymph node. Aberrant exprssion of long non-coding RNAs have been extensively reported to be significantly correlated with lymphatic metastasis of thyroid cancer. However, the clinical significance and functional role of lncRNA-MAPK8IP1P2 in lymphatic metastasis of thyroid cancer remain unclear. Here, we reported that MAPK8IP1P2 was downregulated in thyroid cancer tissues with lymphatic metastasis. Upregulating MAPK8IP1P2 inhibited, while silencing MAPK8IP1P2 enhanced anoikis resistance in vitro and lymphatic metastasis of thyroid cancer cells in vivo. Mechanistically, MAPK8IP1P2 activated Hippo signaling by sponging miR-146b-3p to disrupt the inhibitory effect of miR-146b-3p on NF2, RASSF1, and RASSF5 expression, which further inhibited anoikis resistance and lymphatic metastasis in thyroid cancer. Importantly, miR-146b-3p mimics reversed the inhibitory effect of MAPK8IP1P2 overexpression on anoikis resistance of thyroid cancer cells. In conclusion, our findings suggest that MAPK8IP1P2 may serve as a potential biomarker to predict lymphatic metastasis in thyroid cancer, or a potential therapeutic target in lymphatic metastatic thyroid cancer.

Silencing SAPCD2 Represses Proliferation and Lung Metastasis of Fibrosarcoma by Activating Hippo Signaling Pathway

The primary problem associated with fibrosarcoma is its high potential to metastasize to the lung. Aberrant expression of SAPCD2 has been widely reported to be implicated in the progression and metastasis in multiple cancer types. However, the clinical significance and biological roles of SAPCD2 in fibrosarcoma remain unknown. Here, we reported that SAPCD2 expression was markedly elevated in fibrosarcoma tissues, and its expression was differentially upregulated in fibrosarcoma cell lines compared with that in several primary fibroblast cell lines. Kaplan-Meier survival analysis revealed that SAPCD2 overexpression was significantly correlated with early progression and metastasis, and poor prognosis in fibrosarcoma patients. Our results further showed that silencing SAPCD2 inhibited the proliferation and increased the apoptosis of fibrosarcoma cells in vitro. Importantly, silencing SAPCD2 repressed lung metastasis of fibrosarcoma cells in vivo. Mechanistic investigation further demonstrated that silencing SAPCD2 inhibited the proliferation and lung metastasis of fibrosarcoma cells by activating the Hippo signaling pathway, as evidenced by the finding that constitutively active YAP1, YAP1-S127A, significantly reversed the inhibitory effect of SAPCD2 downregulation on the colony formation and anchorage-independent growth capabilities of fibrosarcoma cells, as well as the stimulatory effect on the apoptotic ratio of fibrosarcoma cells. In conclusion, SAPCD2 promotes the proliferation and lung metastasis of fibrosarcoma cells by regulating the activity of Hippo signaling, and this mechanism represents a potential therapeutic target for the treatment of lung metastatic fibrosarcoma.

Emerging roles of MiR-133a in human cancers

MicroRNAs (miRNAs) can post-transcriptionally regulate the expression of cancer-relevant genes via binding to the 3'-untranslated region (3'-UTR) of the target mRNAs. MiR-133a, as a miRNA, participate in tumorigenesis, progression, autophagy and drug-resistance in various malignancies. Based on the recent insights, we discuss the functions of miR-133a in physiological and pathological processes and its potential effects on cancer diagnosis, prognosis and therapy.

Targeting Akt-associated microRNAs for cancer therapeutics

The uncontrolled growth and spread of abnormal cells because of activating protooncogenes and/or inactivating tumor suppressor genes are the hallmarks of cancer. The PI3K/Akt signaling is one of the most frequently activated pathways in cancer cells responsible for the regulation of cell survival and proliferation in stress and hypoxic conditions during oncogenesis. Non-coding RNAs are a large family of RNAs that are not involved in protein-coding, and microRNAs (miRNAs) are a sub-set of non-coding RNAs with a single strand of 18-25 nucleotides. miRNAs are extensively involved in the post-transcriptional regulation of gene expression and play an extensive role in the regulatory mechanisms including cell differentiation, proliferation, apoptosis, and tumorigenesis. The impact of cancer on mRNA stability and translation efficiency is extensive and therefore, cancerous tissues exhibit drastic alterations in the expression of miRNAs. miRNAs can be modulated by utilizing techniques such as miRNA mimics, miRNA antagonists, or CRISPR/Cas9. In addition to their capacity as potential targets in cancer therapy, they can be used as reliable biomarkers to diagnose the disease at the earliest stage. Recent evidence indicates that microRNA-mediated gene regulation intersects with the Akt pathway, forming an Akt-microRNA regulatory network. miRNAs and Akt in this network operate together to exert their cellular tasks. In the current review, we discuss the Akt-associated miRNAs in several cancers, their molecular regulation, and how this newly emerging knowledge may contribute greatly to revolutionize cancer therapy.

Tribbles-1 Expression and Its Function to Control Inflammatory Cytokines, Including Interleukin-8 Levels are Regulated by miRNAs in Macrophages and Prostate Cancer Cells

The pseudokinase TRIB1 controls cell function in a range of contexts, by regulating MAP kinase activation and mediating protein degradation via the COP1 ubiquitin ligase. TRIB1 regulates polarization of macrophages and dysregulated Trib1 expression in murine models has been shown to alter atherosclerosis burden and adipose homeostasis. Recently, TRIB1 has also been implicated in the pathogenesis of prostate cancer, where it is often overexpressed, even in the absence of genetic amplification. Well described TRIB1 effectors include MAP kinases and C/EBP transcription factors, both in immune cells and in carcinogenesis. However, the mechanisms that regulate TRIB1 itself remain elusive. Here, we show that the long and conserved 3’untranslated region (3’UTR) of TRIB1 is targeted by miRNAs in macrophage and prostate cancer models. By using a systematic in silico analysis, we identified multiple “high confidence” miRNAs potentially binding to the 3’UTR of TRIB1 and report that miR-101-3p and miR-132-3p are direct regulators of TRIB1 expression and function. Binding of miR-101-3p and miR-132-3p to the 3’UTR of TRIB1 mRNA leads to an increased transcription and secretion of interleukin-8. Our data demonstrate that modulation of TRIB1 by miRNAs alters the inflammatory profile of both human macrophages and prostate cancer cells.

Droplet Digital PCR Analysis of Liquid Biopsy Samples Unveils the Diagnostic Role of hsa-miR-133a-3p and hsa-miR-375-3p in Oral Cancer

Simple Summary

Despite the availability of screening programs, oral cancer is often diagnosed due to the lack of effective biomarkers. Therefore, the identification of new effective diagnostic and late prognostic biomarkers is of fundamental importance for the management of this tumor type. In our previous computational study, we have identified a set of microRNAs (miRNAs) significantly dysregulated in oral cancer and with a potential diagnostic and prognostic significance for oral cancer patients. Starting from our preliminary bioinformatics results, the aim of the present study was to validate the diagnostic potential of four selected miRNAs, hsa-miR-133a-3p, hsa-miR-375-3p, hsa-miR-503-5p and hsa-miR-196a-5p, in liquid biopsy samples obtained from oral cancer patients and healthy donors. For this purpose, the expression levels of the selected miRNAs were determined in plasma samples by using specific miRNA probes and droplet digital PCR (ddPCR). The ddPCR results showed that the hsa-miR-133a-3p and hsa-miR-375-3p were significantly down-regulated in oral cancer and their evaluation in liquid biopsy samples can predict the risk of oral cancer development with high sensitivity and specificity. Finally, the computational analysis of miRNA expression and clinical-pathological features of patients allowed us to establish the functional role and prognostic significance of the two validated miRNAs.

Abstract

Despite the availability of screening programs, oral cancer deaths are increasing due to the lack of diagnostic biomarkers leading to late diagnosis and a poor prognosis. Therefore, there is an urgent need to discover novel effective biomarkers for this tumor. On these bases, the aim of this study was to validate the diagnostic potential of microRNAs (miRNAs) through the analysis of liquid biopsy samples obtained from ten oral cancer patients and ten healthy controls. The expression of four selected miRNAs was evaluated by using droplet digital PCR (ddPCR) in a pilot cohort of ten oral cancer patients and ten healthy donors. Bioinformatics analyses were performed to assess the functional role of these miRNAs. The expression levels of the predicted down-regulated hsa-miR-133a-3p and hsa-miR-375-3p were significantly reduced in oral cancer patients compared to normal individuals while no significant results were obtained for the up-regulated hsa-miR-503-5p and hsa-miR-196a-5p. ROC analysis confirmed the high sensitivity and specificity of hsa-miR-375-3p and hsa-miR-133a-3p. Therefore, both miRNAs are significantly down-regulated in cancer patients and can be used as biomarkers for the early diagnosis of oral cancer. The analysis of circulating miRNAs in a larger series of patients is mandatory to confirm the results obtained in this pilot study.

IGF2 loss of imprinting enhances colorectal cancer stem cells pluripotency by promoting tumor autophagy

Cancer stem cells (CSCs) are believed to be the driving force behind the tumor growth. We performed this study to further explore the role of IGF2 epigenetic on CRC stem cells pluripotency which showed that IGF2 LOI CRC cells usually had a higher CD133 expression and sphere forming efficiency than MOI cells. IGF2 LOI CSCs were also found to have a higher level of autophagy than MOI CSCs. Moreover, IGF2/IR-A signal was determined to play a more important role in CSCs formation than IGF2/IGF1R. At last, by using miRNA-195 mimics, we fortunately found the increased IR-A expression might be due to the degradation of miRNA-195 in CRC. In conclusion, our results might reveal that IGF2 LOI could promote CRC stem cells pluripotency by promoting CSCs autophagy. For the degradation of miRNA-195, IGF2 showed a higher ability in interacting with overexpressed IR-A rather than IGF1R which would further activate CSCs autophagy. All these findings might provide a novel mechanistic insight into CRC diagnosis and therapy.

MiRNA-671-5p Promotes prostate cancer development and metastasis by targeting NFIA/CRYAB axis

Prostate cancer (PCa) is the second cause of death due to malignancy among men, and metastasis is the leading cause of mortality in patients with PCa. MicroRNAs (miRNAs) play important regulatory roles in tumor development and metastasis. Here, we identified 13 miRNAs related to PCa metastasis by bioinformatics analysis. Moreover, we found that miR-671-5p was increased in metastatic PCa tissues, and its high expression indicated poor prognosis of PCa. MiR-671-5p could facilitate PCa cells proliferation, migration, and invasion in vitro and vivo. We confirmed that miR-671-5p directly bound to the 3’ untranslated regions of NFIA mRNA, and NFIA directly bound to the CRYAB promoter. High expression of NFIA and CRYAB negatively correlated with the advanced clinicopathological characteristics and metastasis status of PCa patients. Our study demonstrated that miR-671-5p promoted PCa development and metastasis by suppressing NFIA/ CRYAB axis.

MiR-133a acts as a tumor suppressor in lung cancer progression by regulating the LASP1 and TGF-β/Smad3 signaling pathway

BACKGROUND

MiR-133a has been confirmed to be involved in the development of multiple cancers including non-small cell lung cancer (NSCLC). However, the precise molecular mechanism has not yet been fully elucidated. The purpose of this study was to investigate the functional role and underlying mechanism of miR-133a in the progression of NSCLC.

METHODS

Quantitative real-time PCR (qRT-PCR) was performed to measure miR-133a and LASP1 expression in NSCLC tissues and cells. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to detect cell viability. The protein levels were measured by western blot. The tumor growth was measured by xenograft tumor formation assay.

RESULTS

miR-133a was significantly decreased while LASP1 was increased in NSCLC tissues and cells compared with control groups. Moreover, overexpression of miR-133a suppressed cell viability, whereas miR-133a knockdown enhanced the viability of A549 cells. More importantly, LASP1 was verified as a direct target of miR-133a. Moreover, overexpression of miR-133a inhibited the epithelial-mesenchymal transition (EMT) and TGF-β/Smad3 pathways by regulating LASP1 in vitro. In addition, miR-133a mimic suppressed tumor growth by modulating the TGF-β/Smad3 pathway in vivo.

CONCLUSIONS

In conclusion, miR-133a acted as a tumor suppressor in lung cancer progression by regulating the LASP1 and TGF-β/Smad3 signaling pathway.

MiR-27a Facilitates Breast Cancer Progression via GSK-3β

Breast cancer remains one of the leading causes of cancer-associated death in women. MiR-27a is highly expressed in breast cancer tissue. However, the underlying mechanisms that promote breast cancer progression are unknown. In this study, we investigated the regulatory mechanisms of miR-27a and its target glycogen Synthase Kinase 3-β (GSK-3β) in breast cancer cells. We found that miR-27a was highly expressed in breast cancer tissues, which downregulated GSK-3β expression. We further identified GSK-3β as a direct target of miR-27a, and found that the miR-27a mediated suppression of GSK-3β activated Wnt/β-catenin-associated proliferative and invasive factor in breast cancer. The cell transfection assay demonstrated the overexpression of miR-27a also enhanced cell proliferation and invasion, and reduced cell apoptosis through GSK-3β. Finally, we demonstrated that the overexpression of miR-27a facilitated breast cancer progression through its ability to down-regulate the phosphorylation of GSK-3β both in vivo and vitro. These findings highlighted miR-27a as a novel therapeutic target in breast cancer.

Unique, Gender-Dependent Serum microRNA Profile in PLS3 Gene-Related Osteoporosis

Plastin 3 (PLS3), encoded by PLS3, is a newly recognized regulator of bone metabolism, and mutations in the encoding gene result in severe childhood-onset osteoporosis. Because it is an X chromosomal gene, PLS3 mutation-positive males are typically more severely affected whereas females portray normal to increased skeletal fragility. Despite the severe skeletal pathology, conventional metabolic bone markers tend to be normal and are thus insufficient for diagnosing or monitoring patients. Our study aimed to explore serum microRNA (miRNA) concentrations in subjects with defective PLS3 function to identify novel markers that could differentiate subjects according to mutation status and give insight into the molecular mechanisms by which PLS3 regulates skeletal health. We analyzed fasting serum samples for a custom-designed panel comprising 192 miRNAs in 15 mutation-positive (five males, age range 8-76 years, median 41 years) and 14 mutation-negative (six males, age range 8-69 years, median 40 years) subjects from four Finnish families with different PLS3 mutations. We identified a unique miRNA expression profile in the mutation-positive subjects with seven significantly upregulated or downregulated miRNAs (miR-93-3p, miR-532-3p, miR-133a-3p, miR-301b-3p, miR-181c-5p, miR-203a-3p, and miR-590-3p; p values, range .004-.044). Surprisingly, gender subgroup analysis revealed the difference to be even more distinct in female mutation-positive subjects (congruent p values, range .007-.086) than in males (p values, range .127-.843) in comparison to corresponding mutation-negative subjects. Although the seven identified miRNAs have all been linked to bone metabolism and two of them (miR-181c-5p and miR-203a-3p) have bioinformatically predicted targets in the PLS3 3' untranslated region (3'-UTR), none have previously been reported to associate with PLS3. Our results indicate that PLS3 mutations are reflected in altered serum miRNA levels and suggest there is crosstalk between PLS3 and these miRNAs in bone metabolism. These provide new understanding of the pathomechanisms by which mutations in PLS3 lead to skeletal disease and may provide novel avenues for exploring miRNAs as biomarkers in PLS3 osteoporosis or as target molecules in future therapeutic applications. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Human Mesenchymal Stem Cell Derived Exosomes Enhance Cell-Free Bone Regeneration by Altering Their miRNAs Profiles

Implantation of stem cells for tissue regeneration faces significant challenges such as immune rejection and teratoma formation. Cell-free tissue regeneration thus has a potential to avoid these problems. Stem cell derived exosomes do not cause immune rejection or generate malignant tumors. Here, exosomes that can induce osteogenic differentiation of human mesenchymal stem cells (hMSCs) are identified and used to decorate 3D-printed titanium alloy scaffolds to achieve cell-free bone regeneration. Specifically, the exosomes secreted by hMSCs osteogenically pre-differentiated for different times are used to induce the osteogenesis of hMSCs. It is discovered that pre-differentiation for 10 and 15 days leads to the production of osteogenic exosomes. The purified exosomes are then loaded into the scaffolds. It is found that the cell-free exosome-coated scaffolds regenerate bone tissue as efficiently as hMSC-seeded exosome-free scaffolds within 12 weeks. RNA-sequencing suggests that the osteogenic exosomes induce the osteogenic differentiation by using their cargos, including upregulated osteogenic miRNAs (Hsa-miR-146a-5p, Hsa-miR-503-5p, Hsa-miR-483-3p, and Hsa-miR-129-5p) or downregulated anti-osteogenic miRNAs (Hsa-miR-32-5p, Hsa-miR-133a-3p, and Hsa-miR-204-5p), to activate the PI3K/Akt and MAPK signaling pathways. Consequently, identification of osteogenic exosomes secreted by pre-differentiated stem cells and the use of them to replace stem cells represent a novel cell-free bone regeneration strategy.

PSMA-Targeting Reduction-Cleavable Hyperbranched Polyamide-Amine Gene Delivery System to Treat the Bone Metastases of Prostate Cancer

Objective

This study aimed to develop aptamer-anchored hyperbranched poly(amido amine) (HPAA) for the systemic delivery of miRNA-133a-3p and to evaluate its therapeutic potential against bone metastasis of prostate cancer in vivo and in vitro.

Methods

A glutathione (GSH)-responsive cationic HPAA was prepared by the Michael addition reaction. Furthermore, HPAA-PEG was produced by PEGylation, and then the aptamer targeted to prostate-specific membrane antigen (PSMA) was conjugated to the HPAA-PEG. The obtained HPAA-PEG-APT could form nanocomplexes with miRNA-133a-3p through electrostatic adsorption.

Results

The results of immunocytochemistry indicated that the complexes could target PSMA-expressing LNCaP cells. The ability of HPAA-PEG-APT to facilitate the delivery of miRNA-133a-3p into LNCaP cells was proven, and HPAA-PEG-APT/miRNA-133a-3p demonstrated enhanced antitumor activity, lower cytotoxicity and better biocompatibility in vitro. Moreover, in a mouse tibial injection tumor model, the intravenous injection of the HPAA-PEG-APT/miRNA-133a-3p complex significantly inhibited cancer growth and extended the survival time.

Conclusion

This study provided an aptamer-anchored HPAA-loaded gene system to deliver miRNA-133a-3p for better therapeutic efficacy of bone metastasis of prostate cancer.

miR-133a-3p Regulates Hepatocellular Carcinoma Progression Through Targeting CORO1C

Introduction

MicroRNAs (miRNAs) are key modulators for gene expression via inducing translational repression or target gene degradation. miR-133a-3p was reported to stimulate or inhibit cancer progression but its role in hepatocellular carcinoma (HCC) remains to be explored.

Methods

Quantitative real-time PCR (RT-qPCR) was utilized to explore miR-133a-3p expression level in HCC cells. Dual-luciferase activity reporter assay was used to validate the direct interaction between miR-133a-3p and coronin-like actin-binding protein 1C (CORO1C). In addition, we analyzed the expression levels of miR-133a-3p and CORO1C in HCC tissues and normal tissues on the UCALAN website. Functional assays including cell counting kit-8 assay, colony formation assay, flow cytometry analysis and transwell invasion assay were conducted to explore the biological functions of miR-133a-3p in HCC.

Results

miR-133a-3p was found to have downregulated expression in HCC tissues and cells. Meanwhile, we showed that low miR-133a-3p levels were correlated with poorer overall survival of HCC patients. Overexpression of miR-133a-3p suppressed HCC cell growth and invasion but promoted cell apoptosis via targeting CORO1C.

Discussion

Our results revealed a novel mechanism of miR-133a-3p in regulating HCC progression and provided evidence that miR-133a-3p functions as a tumor suppressor in HCC.

Restored microRNA-133a-3p or Depleted PSAT1 Restrains Endothelial Cell Damage-Induced Intracranial Aneurysm Via Suppressing the GSK3β/β-Catenin Pathway

It is unclear about the functional role of microRNA-133a-3p (miR-133a-3p) in intracranial aneurysm (IA). Hence, the aim of the present study was to investigate the regulatory role of miR-133a-3p on the regulation of vascular endothelial injury-induced IA through phosphoserine aminotransferase 1 (PSAT1)/glycogen synthase kinase 3β (GSK3β)/β-catenin signaling pathway. Normal intracranial arteriole tissues and IA tissues were gathered from patients with brain trauma and IA. The expression of miR-133a-3p, PSAT1, GSK3β, and β-catenin in tissues was determined by RT-qPCR and western blot analysis. The endothelial cells (ECs) of the human IA were cultured and treated with miR-133a-3p mimic and si-PSAT1 to determine their functions in endothelial cell migration, apoptosis, and proliferation. The expression of miR-133a-3p, PSAT1, GSK3β, β-catenin, Ki-67, CyclinD1, Bax, and Bcl-2 in ECs were tested by RT-qPCR or western blot analysis. Moreover, IA rat model was established to detect the pathological changes and the expression of miR-133a-3p, PSAT1, GSK3β, β-catenin, VEGF, and MMP-9 in IA tissues in vivo. Expression of miR-133a-3p was related to the number and size of IA. MiR-133a-3p expression was deceased and the PSAT1, GSK3β, and β-catenin expression was raised in IA. Restored miR-133a-3p and depleted PSAT1 alleviated the pathological change; reduced PSAT1, GSK3β, and β-catenin expression in IA; suppressed apoptosis and advanced proliferation and migration of IA ECs, as well as reduced VEGF and MMP-9 expression in IA tissues in vivo. Our study suggests that overexpression of miR-133a-3p or downregulation of PSAT1 restrains endothelial cell damage and advances endothelial cell proliferation via inhibiting the GSK3β/β-catenin pathway in IA. MiR-133a-3p might be a potential candidate marker and therapeutic target for IA.

An overview of advances in multi-omics analysis in prostate cancer

Prostate cancer (PCa) is a deadly disease for men, and studies of all types of omics data are necessary to promote precision medicine. The maturity of sequencing technology, the improvements of computer processing power, and the progress achieved in omics analysis methods have improved research efficiency and saved research costs. The occurrence and development of PCa is due to multisystem and multilevel pathological changes. Although omics research at a single level is important, this approach often has limitations. In contrast, the combined analysis of multiple types of omics data can better analyze PCa changes as a whole, thus ensuring the validity of research results to the greatest extent. This paper introduces the applications of single omics in PCa and then summarizes research progress in the combined analysis of two or more types of omics data, so as to systematically and comprehensively analyze the necessity of combined analysis of multiple omics data in PCa.

Upregulation of miR-133a-3p enhances Bufothionine-induced gastric cancer cell death by modulating IGF1R/PI3K/Akt signal pathway mediated ER stress

AIMS

Bufothionine had been used for gastric cancer (GC) treatment, and this study managed to uncover the underlying mechanisms.

MATERIALS AND METHODS

Cell proliferation was determined by CCK-8 assay and colony formation assay. Flow cytometry (FCM) and TUNEL assay were used to measure cell apoptosis ratio. Intracellular ROS was measured by DCFH-DA probes. qRT-PCR was used to determine miRNAs levels. Western Blot was performed to probe proteins. Dual-luciferase reporter gene system was employed to validate the binding sites of miR-133a-3p and 3'UTR regions of IGF1R mRNA. Immunohistochemistry (IHC) was used to determine the expressions of Ki-67 in mice tumor tissues.

KEY FINDINGS

Bufothionine inhibited cell viability, triggered ER stress and promoted ROS production in GC cells, and both ER stress inhibitor Salburinal (Sal) and ROS scavenger (NAC) abrogated Bufothionine induced GC cell death. Besides, miR-133a-3p was upregulated by Bufothionine, and Bufothionine-induced cell death was enhanced by miR-133a-3p overexpression while alleviated by miR-133a-3p knockdown. Furthermore, miR-133a-3p inactivated PI3K/Akt signal pathway by sponging IGF1R, and Bufothionine inhibited insulin-like growth factor 1 receptor (IGF1R) and inactivated PI3K/Akt cascade by upregulating miR-133a-3p. Notably, the promoting effects of overexpressed miR-133a-3p on Bufothionine-induced GC cell death were abrogated by overexpressing IGF1R, and aggravated by the PI3K/Akt cascade inhibitor (LY294002).

SIGNIFICANCE

Bufothionine promoted GC cell death by triggering miR-133a-3p/IGF1R/PI3K/Akt axis mediated ER stress and ROS production.

Snail promotes prostate cancer migration by facilitating SPOP ubiquitination and degradation

Prostate cancer (PCa) is the second leading cause of cancer-associated mortality in men. Speckle-type pox virus and zinc finger protein (SPOP), the most frequently mutated gene in PCa, functions as a tumor suppressor via degradation of cancer-promoting substrates. However, its upstream regulation in PCa metastasis remains poorly determined. Here, in a Snail-induced metastatic PCa model, we observed an accelerated degradation of SPOP protein in cells, which is crucial for the PCa migration and activation of the AKT signaling pathway. Mechanistically, we demonstrated that binding to Snail promoted SPOP ubiquitination and degradation. Moreover, the bric-a-brac/tramtrack/broad complex (BTB) domain of SPOP is turned out to be essential for Snail-mediated SPOP degradation. Thus, our findings reveal a post-translational level regulation of SPOP expression that facilitates the metastasis of PCa cells.

Validation of the four-miRNA biomarker panel MiCaP for prediction of long-term prostate cancer outcome

Improved prostate cancer prognostic biomarkers are urgently needed. We previously identified the four-miRNA prognostic biomarker panel MiCaP ((miR-23a-3p × miR-10b-5p)/(miR-133a-3p × miR-374b-5p)) for prediction of biochemical recurrence (BCR) after radical prostatectomy (RP). Here, we identified an optimal numerical cut-off for MiCaP dichotomisation using a training cohort of 475 RP patients and tested this in an independent cohort of 281 RP patients (PCA281). Kaplan–Meier, uni- and multivariate Cox regression analyses were conducted for multiple endpoints: BCR, metastatic-(mPC) and castration-resistant prostate cancer (CRPC), prostate cancer-specific (PCSS) and overall survival (OS). Functional effects of the four MiCaP miRNAs were assessed by overexpression and inhibition experiments in prostate cancer cell lines. We found the numerical value 5.709 optimal for MiCaP dichotomisation. This was independently validated in PCA281, where a high MiCaP score significantly [and independent of the Cancer of the Prostate Risk Assessment Postsurgical (CAPRA-S) score] predicted BCR, progression to mPC and CRPC, and PCSS, but not OS. Harrell’s C-index increased upon addition of MiCaP to CAPRA-S for all endpoints. Inhibition of miR-23a-3p and miR-10b-5p, and overexpression of miR-133a-3p and miR-374b-5p significantly reduced cell survival. Our results may promote future implementation of a MiCaP-based test for improved prostate cancer risk stratification.

MIR205HG acts as a ceRNA to expedite cell proliferation and progression in lung squamous cell carcinoma via targeting miR-299-3p/MAP3K2 axis

INTRODUCTION

Long noncoding RNAs (lncRNAs) have been associated with many types of cancers, but their molecular mechanisms in lung squamous cell carcinoma (LUSC) have not been fully studied. Therefore, the current study investigated the regulation role of microRNA-205 host gene (MIR205HG) in LUSC and recognized the target genes managed by this lncRNA.

METHODS

MIR205HG expression was assessed by the quantitative real-time polymerase chain reaction (qRT-PCR) analysis. The effects of silenced MIR205HG on cell biological behaviors were detected by colony formation assay, transwell assay, flow cytometry analysis and western blot analysis. Luciferase reporter assay and RNA immunoprecipitation (RIP) assay were utilized to proof the binding relationship between miR-299-3p and MIR205HG/mitogen-activated protein kinase kinase kinase 2 (MAP 3 K2).

RESULTS

The expression levels of MIR205HG in LUSC tissues and cell lines were obviously up-regulated. Down-regulation of MIR205HG expression remarkably reduced cell proliferation, migration and epithelial-to-mesenchymal transition (EMT) progression, whereas promoted cell apoptosis. MIR205HG could bind with miR-299-3p and down-regulation of MIR205HG elevated miR-299-3p expression. MAP 3 K2 acted as the target gene of miR-299-3p and was up-regulated by MIR205HG overexpression. Overexpressing MAP 3 K2 could counteract the effects of down-regulating MIR205HG on LUSC progression to some degree.

CONCLUSION

MIR205HG acts as a competing endogenous RNA (ceRNA) to expedite cell proliferation and progression via targeting miR-299-3p in LUSC.

Role of PI3K/AKT pathway in cancer: the framework of malignant behavior

Given that the PI3K/AKT pathway has manifested its compelling influence on multiple cellular process, we further review the roles of hyperactivation of PI3K/AKT pathway in various human cancers. We state the abnormalities of PI3K/AKT pathway in different cancers, which are closely related with tumorigenesis, proliferation, growth, apoptosis, invasion, metastasis, epithelial-mesenchymal transition, stem-like phenotype, immune microenvironment and drug resistance of cancer cells. In addition, we investigated the current clinical trials of inhibitors against PI3K/AKT pathway in cancers and found that the clinical efficacy of these inhibitors as monotherapy has so far been limited despite of the promising preclinical activity, which means combinations of targeted therapy may achieve better efficacies in cancers. In short, we hope to feature PI3K/AKT pathway in cancers to the clinic and bring the new promising to patients for targeted therapies.

Ras and Wnt Interaction Contribute in Prostate Cancer Bone Metastasis

Prostate cancer (PCa) is one of the most prevalent and malignant cancer types in men, which causes more than three-hundred thousand cancer death each year. At late stage of PCa progression, bone marrow is the most often metastatic site that constitutes almost 70% of metastatic cases of the PCa population. However, the characteristic for the osteo-philic property of PCa is still puzzling. Recent studies reported that the Wnt and Ras signaling pathways are pivotal in bone metastasis and that take parts in different cytological changes, but their crosstalk is not well studied. In this review, we focused on interactions between the Wnt and Ras signaling pathways during each stage of bone metastasis and present the fate of those interactions. This review contributes insights that can guide other researchers by unveiling more details with regard to bone metastasis and might also help in finding potential therapeutic regimens for preventing PCa bone metastasis.

Downregulation of the circadian rhythm regulator HLF promotes multiple-organ distant metastases in non-small cell lung cancer through PPAR/NF-κb signaling

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death due to its early recurrence and widespread metastatic potential. Accumulating studies have reported that dysregulation of circadian rhythms-associated regulators is implicated in the recurrence and metastasis of NSCLC. Therefore, identification of metastasis-associated circadian rhythm genes is clinically necessary. Here we report that the circadian gene hepatic leukemia factor (HLF), which was dramatically reduced in early-relapsed NSCLC tissues, was significantly correlated with early progression and distant metastasis in NSCLC patients. Upregulating HLF inhibited, while silencing HLF promoted lung colonization, as well as metastasis of NSCLC cells to bone, liver and brain in vivo. Importantly, downexpression of HLF promoted anaerobic metabolism to support anchorage-independent growth of NSCLC cells under low nutritional condition by activating NF-κB/p65 signaling through disrupting translocation of PPARα and PPARγ. Further investigations revealed that both genetic deletion and methylation contribute to downexpression of HLF in NSCLC tissues. In conclusion, our results shed light on a plausible mechanism by which HLF inhibits distant metastasis in NSCLC, suggesting that HLF may serve as a novel target for clinical intervention in NSCLC.

ZEB1-AS1/miR-133a-3p/LPAR3/EGFR axis promotes the progression of thyroid cancer by regulating PI3K/AKT/mTOR pathway

Background

Thyroid cancer (TC) is a member of common malignant tumors in endocrine system. To develop effective treatment, further comprehension of understanding molecular mechanism in TC is necessary. In this research, we attempted to search the underlying molecular mechanism in TC.

Methods

ZEB1-AS1 expression was analyzed via qRT-PCR analysis. CCK-8, colony formation, flow cytometry and TUNEL assays were used to evaluate TC cell growth. The interaction between miR-133a-3p and LPAR3, EGFR and ZEB1-AS1 was testified through using RNA pull down and luciferase reporter assays.

Results

LPAR3 and EGFR were expressed at high levels in TC tissues and cell lines. Besides, both LPAR3 and EGFR could promote TC cell growth. Later, miR-133a-3p was searched as an upstream gene of LPAR3 and EGFR, and LPAR3 could partially rescue the suppressive effect of miR-133a-3p overexpression on TC progression, whereas the co-transfection of LPAR3 and EGFR completely restored the inhibition. Next, ZEB1-AS1 was confirmed as a sponge of miR-133a-3p. ZEB1-AS1 has a negative correlation with miR-133a-3p and a positive association with LPAR3 and EGFR through ceRNA analysis. Importantly, ZEB1-AS1 boosted the proliferation and suppressed the apoptosis in TC cells. Through restoration assays, we discovered that ZEB1-AS1 regulated LPAR3 and EGFR expression to mediate TC cell proliferation and apoptosis by sponging miR-133a-3p. Further investigation also indicated the oncogenic role of ZEB1-AS1 by mediating PI3K/AKT/mTOR pathway.

Conclusions

ZEB1-AS1 could be an underlying biomarker in TC.

Overexpression of miR-133a-3p inhibits fibrosis and proliferation of keloid fibroblasts by regulating IRF5 to inhibit the TGF-β/Smad2 pathway

AIM

Keloid is a benign dermal tumor with excessive hyperplasia and deposition of collagen. As a common tumor suppressor gene, miR-133a-3p has not been studied in keloid. This study will delve into the specific mechanism of miR-133a-3p in keloid.

METHODS

Normal skin fibroblasts and keloid fibroblasts (KFs) were first isolated from patients' normal skin and keloid, and cells were identified by morphological observation and immunofluorescence. The expressions of miR-133a-3p and extracellular matrix (ECM)-associated markers (Collagen I, III and α smooth muscle activin) were detected by Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Cell viability and apoptosis of KFs were examined by Cell Counting Kit-8 assay, flow cytometry, and Caspase-3 colorimetry. TargetScan predicted target gene for miR-133a-3p was verified by luciferase assay, qRT-PCR and Western Blot (WB). WB was used to study protein expression of TGFBR1, phosphorylated -Smad2 (p-Smad2) and Smad2. Finally, a series of rescue experiments were performed to verify the intervention of target genes on miR-133a-3p.

RESULTS

MiR-133a-3p was lowly expressed in keloid tissue and KFs. Overexpression of miR-133a-3p inhibited the expression of ECM-associated markers, reduced KFs viability, and promoted apoptosis. It was verified that interference regulator 5 (IRF5) is miR-133a-3p target gene. The rescue experiments showed that IRF5 reversed the effect of miR-133a-3p mimic on inhibiting fibrosis, and reversed the effects on promoting apoptosis and reducing cell proliferation.

CONCLUSION

Overexpressed miR-133a-3p inhibits fibrosis by down-regulating IRF5 and thus inhibiting the TGF-β/Smad2 pathway. And it also promotes KFs apoptosis and reduces proliferation.

Oncogenic and tumor-suppressive microRNAs in prostate cancer

MicroRNAs are known to be dysregulated in prostate cancer. These small noncoding RNAs can function as biomarkers and are involved in the biology of prostate cancer. The canonical mechanism for microRNAs is post-transcription regulation of gene expression via binding to the 3' untranslated region of mRNAs, resulting in RNA degradation and/or translational repression. Thus, oncogenic microRNAs, also known as oncomiRs, often have high expression in prostate cancer and target the mRNAs of tumor suppressors. Conversely, tumor-suppressive microRNAs have reduced expression in cancer and typically target oncogenes. Some microRNAs function outside the classical mechanism and serve to stabilize their mRNA targets. Herein, we review contemporary studies that demonstrate oncogenic and tumor-suppressive activity of microRNAs in prostate cancer.

MiRNA-Based Inspired Approach in Diagnosis of Prostate Cancer

Prostate cancer is one of the most encountered cancer diseases in men worldwide and in consequence it requires the improvement of therapeutic strategies. For the clinical diagnosis, the standard approach is represented by solid biopsy. From a surgical point of view, this technique represents an invasive procedure that may imply several postoperative complications. To overcome these impediments, many trends are focusing on developing liquid biopsy assays and on implementing them in clinical practice. Liquid samples (blood, urine) are rich in analytes, especially in transcriptomic information provided by genetic markers. Additionally, molecular characterization regarding microRNAs content reveals outstanding prospects in understanding cancer progression mechanisms. Moreover, these analytes have great potential for prostate cancer early detection, more accurate prostate cancer staging and also for decision making respecting therapy schemes. However, there are still questionable topics and more research is needed to standardize liquid biopsy-based techniques.

Identification of the key genes and microRNAs in adult acute myeloid leukemia with FLT3 mutation by bioinformatics analysis

Background: Associated with poor prognosis, FMS-like tyrosine kinase 3 (FLT3) mutation appeared frequently in acute myeloid leukemia (AML). Herein, we aimed to identify the key genes and miRNAs involved in adult AML with FLT3 mutation and find possible therapeutic targets for improving treatment. Materials: Gene and miRNA expression data and survival profiles were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. EdgeR of R platform was applied to identify the differentially expressed genes and miRNAs (DEGs, DE-miRNAs). Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed by Metascape and DAVID. And protein-protein interaction network, miRNA-mRNA regulatory network and clustering modules analyses were performed by STRING database and Cytoscape software. Results: Survival analysis showed FLT3 mutation led to adverse outcome in AML. 24 DE-miRNAs (6 upregulated, 18 downregulated) and 250 DEGs (54 upregulated, 196 downregulated) were identified. Five miRNAs had prognostic value and the results matched their expression levels (miR-1-3p, miR-10a-3p, miR-10a-5p, miR-133a-3p and miR-99b-5p). GO analysis showed DEGs were enriched in skeletal system development, blood vessel development, cartilage development, tissue morphogenesis, cartilage morphogenesis, cell morphogenesis involved in differentiation, response to growth factor, cell-substrate adhesion and so on. The KEGG analysis showed DEGs were enriched in PI3K-Akt signaling pathway, ECM-receptor interaction and focal adhesion. Seven genes (LAMC1, COL3A1, APOB, COL1A2, APP, SPP1 and FSTL1) were simultaneously identified by hub gene analysis and module analysis. SLC14A1, ARHGAP5 and PIK3CA, the target genes of miR-10a-3p, resulted in poor prognosis. Conclusion: Our study successfully identified molecular markers, processes and pathways affected by FLT3 mutation in AML. Furthermore, miR-10a-3p, a novel oncogene, might involve in the development of FLT3 mutation adult AML by targeting SLC14A1, ARHGAP5 and PIK3CA.

MiR-133a-5p inhibits androgen receptor (AR)-induced proliferation in prostate cancer cells via targeting FUsed in Sarcoma (FUS) and AR

Androgens and androgen receptors are vital factors involved in prostate cancer progression, and androgen ablation therapies are commonly employed to treat advanced prostate cancer. Previously, FUsed in Sarcoma (FUS) was identified as an AR-interacting protein that enhances AR transcriptional activity. In the present study, we attempted to identify miRNAs that might target both FUS and AR to inhibit FUS and AR expression. Based on TCGA data and the online tools UALCAN, Kaplan Meier-plotter (KMplot), LncTar and miRWalk prediction, miR-133a-5p was selected. MiR-133a-5p expression was significantly downregulated in prostate cancer, and low miR-133a-5p expression was correlated with low survival probability. As predicted by LncTar and miRWalk, miR-133a-5p could bind to the 3'UTR of FUS and AR to inhibit their expression. MiR-133a-5p overexpression significantly suppressed the cell viability of the AR-positive prostate cancer cell lines VCaP and LNCaP, inhibited the expression of FUS, AR, as well as AR downstream targets IGF1R and EGFR. More importantly, miR-133a inhibition increased cancer cell proliferation as well as the expression of AR and AR downstream factors, while FUS knockdown exerted an opposite effect; the effect of miR-133a on cancer cell proliferation and AR could be significantly reversed by FUS knockdown. Moreover, IGF1R and EGFR knockdown reversed the effect of the miR-133a-5p inhibition. In summary, miR-133a-5p inhibits AR-positive prostate cancer cell proliferation by targeting FUS/AR, thus improving the resistance of prostate cancer to androgen ablation therapies, which requires further in vivo validation. We provided a novel miRNA regulation mechanism for proliferation regulation in AR-positive prostate cancer cells.

miR-424-5p Promotes Anoikis Resistance and Lung Metastasis by Inactivating Hippo Signaling in Thyroid Cancer

miR-424-5p has been widely identified to function as an oncomiR in multiple human cancer types. However, the biological function of miR-424-5p in distant metastasis of thyroid cancer, as well as the underlying mechanism, remains not clarified yet. In the current study, miR-424-5p expression was elucidated in 10 paired fresh thyroid cancer tissues and the thyroid cancer dataset from The Cancer Genome Atlas (TCGA). Lung metastasis colonization models in vivo and functional assays in vitro were used to determine the role of miR-424-5p in thyroid cancer. Bioinformatics analysis, western blot, luciferase reporter, and immunofluorescence assays were applied to identify the potential targets and underlying mechanism involved in the functional role of miR-424-5p in lung metastasis of thyroid cancer. Here, we reported that miR-424-5p was upregulated in thyroid cancer, and overexpression of miR-424-5p significantly correlated with distant metastasis of thyroid cancer. Upregulating miR-424-5p promoted, whereas silencing miR-424-5p inhibited, anoikis resistance in vitro and lung metastasis in vivo. Mechanistic investigation further revealed that miR-424-5p promoted anoikis resistance and lung metastasis by inactivating Hippo signaling via simultaneously targeting WWC1, SAV1, and LAST2. Therefore, our results support the idea that miR-424-5p may serve as a potential therapeutic target in lung metastasis of thyroid cancer.

The Effects of TGF-β Signaling on Cancer Cells and Cancer Stem Cells in the Bone Microenvironment

BACKGROUND

Transforming growth factor-β (TGF-β) plays a key role in bone metastasis formation; we hypothesized the possible involvement of TGF-β in the induction of cancer stem cells (CSCs) in the bone microenvironment (micro-E), which may be responsible for chemo-resistance.

METHODS

Mouse mammary tumor cells were implanted under the dorsal skin flap over the calvaria and into a subcutaneous (subQ) lesions in female mice, generating tumors in the bone and subQ micro-Es. After implantation of the tumor cells, mice were treated with a TGF-β R1 kinase inhibitor (R1-Ki).

RESULTS

Treatment with R1-Ki decreased tumor volume and cell proliferation in the bone micro-E, but not in the subQ micro-E. R1-Ki treatment did not affect the induction of necrosis or apoptosis in either bone or subQ micro-E. The number of cells positive for the CSC markers, SOX2, and CD166 in the bone micro-E, were significantly higher than those in the subQ micro-E. R1-Ki treatment significantly decreased the number of CSC marker positive cells in the bone micro-E but not in the subQ micro-E. TGF-β activation of the MAPK/ERK and AKT pathways was the underlying mechanism of cell proliferation in the bone micro-E. BMP signaling did not play a role in cell proliferation in either micro-E.

CONCLUSION

Our results indicated that the bone micro-E is a key niche for CSC generation, and TGF-β signaling has important roles in generating CSCs and tumor cell proliferation in the bone micro-E. Therefore, it is critically important to evaluate responses to chemotherapeutic agents on both cancer stem cells and proliferating tumor cells in different tumor microenvironments in vivo.

MiR-1827 functions as a tumor suppressor in lung adenocarcinoma by targeting MYC and FAM83F

The bioactivity of microRNA-1827 (miR-1827) in lung adenocarcinoma cells would be explored. The expression level of gene and miR-1827 in 76 pairs of lung adenocarcinoma tissues and adjacent counterparts were analyzed by a quantitative real-time polymerase chain reaction. Primary lung adenocarcinoma cells were derived from patients' tissues. These cells were treated with miR-1827 agomir to mimic the upregulation of endogenous miR-1827. The malignant degree of lung adenocarcinoma cells in vitro was evaluated by cell proliferation, colony formation, transwell invasion, and apoptosis assays. Western blot analysis was used to observe the transition of lung adenocarcinoma cells from epithelial-to-mesenchymal. Target genes of miR-1827 were predicted by bioinformatics analysis. In addition, the interaction between miR-1827 and candidate messenger RNAs was verified by dual-luciferase reporter assay and AGO2-RNA immunoprecipitation. Besides, the effect of miR-1827 on tumors was verified by in vivo experiments. Transient gene overexpression was achieved by plasmids transfection. In this study, we found that the expression of miR-1827 was downregulated in lung adenocarcinoma, and its low expression was significantly correlated with the progression of lung adenocarcinoma and poor prognosis of patients. miR-1827 overexpression remarkably reduced the malignancy of primary lung adenocarcinoma cells in vitro. MYC and FAM83F were identified as two targeted genes of miR-1827 in lung adenocarcinoma cells. The levels of these two genes were upregulated in lung adenocarcinoma, and their high expression was significantly associated with the progression of lung adenocarcinoma and poor prognosis of patients. Overexpression of MYC or FAM83F attenuated the effects of miR-1827 on primary lung adenocarcinoma cells in vitro. In addition, in vivo experiments showed that miR-1827 inhibited tumor growth by reducing the levels of MYC and FAM83F. In conclusion, miR-1827 might repress the development of lung adenocarcinoma by targeting oncogenic genes MYC and FAM83F.

Transcriptional downregulation of miR-127-3p by CTCF promotes prostate cancer bone metastasis by targeting PSMB5

Prostate cancer (PCa) is one of the most common cancers in males and particularly tends to metastasize to bone. Currently, metastatic bone disease is incurable, and new therapies need to be developed. Our study aims to determine the role of miR-127-3p in PCa metastasis to bone. The results demonstrate that miR-127-3p is markedly reduced in bone metastasis-positive PCa tissues relative to that in bone metastasis-negative PCa tissues. Furthermore, overexpressing miR-127-3p inhibits PCa cell invasion and migration in vitro by targeting the proteasome β-subunit PSMB5. Moreover, CCCTC-binding factor (CTCF) transcriptionally inhibits miR-127-3p by interacting with the miR-127-3p promoter. Collectively, this study uncovers a novel mechanism of the CTCF/miR-127-3p/PSMB5 axis in promoting PCa bone metastasis, indicating that miR-127-3p could function as a promising therapeutic target against bone metastasis.

Effect of microRNA-133a-3p/matrix metalloproteinase-9 axis on the growth of atherosclerotic vascular smooth muscle cells

Atherosclerosis (AS) is the leading cause of cardiovascular disease and poses a threat to human health. MicroRNAs (miRNAs/miRs) are a group of endogenous small non-coding RNAs that have been identified to serve important roles in AS. However, the expression and role of miR-133a-3p in AS remains unclear. The aim of the present study was to investigate miR-133a-3p in AS and to determine its underlying mechanism. The level of miR-133a-3p expression in the blood and vascular plaque tissue of patients with AS was detected via reverse transcription-quantitative PCR (RT-qPCR). The role of miR-133a-3p in human vascular smooth muscle cells (hVSMCs) was investigated, following upregulation and downregulation of this miR in hVSMCs. Cell proliferation and apoptosis were determined using a Cell Counting kit-8 assay and flow cytometry, respectively. The results demonstrated the downregulation of miR-133a-3p in the blood and vascular plaque tissue of patients with AS. Matrix metallopeptidase-9 (MMP-9) was revealed to be a direct target gene of miR-133a-3p, which was upregulated in the blood and vascular plaque tissue of patients with AS. Furthermore, MMP-9 was determined to be negatively regulated by miR-133a-3p in hVSMCs. In addition, significant inhibition of hVSMC proliferation and induction of cell apoptosis were observed following MMP-9 downregulation and following transfection with the miR-133a-3p mimic. The effects of the miR-133a-3p mimic on hVSMC proliferation and apoptosis were reversed by MMP-9 over-expression. Overall, the results indicated that miR-133a-3p was downregulated in AS, which results in the inhibition of hVSMC proliferation and the induction of cell apoptosis via MMP-9. miR-133a-3p may therefore be a promising therapeutic target for the treatment of AS.

Copy number gain of ZEB1 mediates a double-negative feedback loop with miR-33a-5p that regulates EMT and bone metastasis of prostate cancer dependent on TGF-β signaling

Background: The reciprocal repressive loop between ZEB1 and miRNAs has been extensively reported to play an important role in tumor progression and metastasis of various human tumor types. The aim of this study was to elucidate the role and the underlying mechanism of the double-negative feedback loop between ZEB1and miR-33a-5p in bone metastasis of prostate cancer (PCa).

Methods: miR-33a-5p expression was examined in 40 bone metastatic and 165 non-bone metastatic PCa tissues by real-time PCR. Statistical analysis was performed to evaluate the clinical correlation between miR-33a-5p expression and clinicopathological characteristics, and overall and bone metastasis-free survival in PCa patients. The biological roles of miR-33a-5p in bone metastasis of PCa were investigated both by EMT and the Transwell assay in vitro, and by a mouse model of left cardiac ventricle inoculation in vivo. siRNA library, real-time PCR and chromatin immunoprecipitation (ChIP) were used to identify the underlying mechanism responsible for the decreased expression of miR-33a-5p in PCa. Bioinformatics analysis, Western blotting and luciferase reporter analysis were employed to examine the relationship between miR-33a-5p and its potential targets. Clinical correlation of miR-33a-5p with its targets was examined in human PCa tissues and primary PCa cells.

Results: miR-33a-5p expression was downregulated in PCa tissues with bone metastasis and bone-derived cells, and low expression of miR-33a-5p strongly and positively correlated with advanced clinicopathological characteristics, and shorter overall and bone metastasis-free survival in PCa patients. Upregulating miR-33a-5p inhibited, while silencing miR-33a-5p promoted EMT, invasion and migration of PCa cells. Importantly, upregulating miR-33a-5p significantly repressed bone metastasis of PC-3 cells in vivo. Our results further revealed that recurrent ZEB1 upregulation induced by copy number gains transcriptionally inhibited miR-33a-5p expression, contributing to the reduced expression of miR-33a-5p in bone metastatic PCa tissues. In turn, miR-33a-5p formed a double negative feedback loop with ZEB1 in target-independent manner, which was dependent on TGF-β signaling. Finally, the clinical negative correlations of miR-33a-5p with ZEB1 expression and TGF-β signaling activity were demonstrated in PCa tissues and primary PCa cells.

Conclusion: Our findings elucidated that copy number gains of ZEB1-triggered a TGF-β signaling-dependent miR-33a-5p-mediated negative feedback loop was highly relevant to the bone metastasis of PCa.

MicroRNAs contribute to ATP-binding cassette transporter- and autophagy-mediated chemoresistance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has an elevated mortality rate, largely because of high recurrence and metastasis. Additionally, the main obstacle during treatment of HCC is that patients usually develop resistance to chemotherapy. Cancer drug resistance involves many different mechanisms, including alterations in drug metabolism and processing, impairment of the apoptotic machine, activation of cell survival signaling, decreased drug sensitivity and autophagy, among others. Nowadays, miRNAs are emerging as master regulators of normal physiology- and tumor-related gene expression. In HCC, aberrant expression of many miRNAs leads to chemoresistance. Herein, we particularly analyzed miRNA impact on HCC resistance to drug therapy. Certain miRNAs target ABC (ATP-binding cassette) transporter genes. As most of these miRNAs are downregulated in HCC, transporter levels increase and intracellular drug accumulation decrease, turning cells less sensitive to death. Others miRNAs target autophagy-related gene expression, inhibiting autophagy and acting as tumor suppressors. Nevertheless, due to its downregulation in HCC, these miRNAs do not inhibit autophagy or tumor growth and, resistance is favored. Concluding, modulation of ABC transporter and/or autophagy-related gene expression or function by miRNAs could be determinant for HCC cell survival under chemotherapeutic drug treatment. Undoubtedly, more insights on the biological processes, signaling pathways and/or molecular mechanisms regulated by miRNAs are needed. Anyway, miRNA-based therapy together with conventional chemotherapeutic drugs has a great future in cancer therapy.

Valproic acid exhibits anti-tumor activity selectively against EGFR/ErbB2/ErbB3-coexpressing pancreatic cancer via induction of ErbB family members-targeting microRNAs

Background

Deregulated ErbB signaling plays an important role in tumorigenesis of pancreatic cancer. However, patients with pancreatic cancer benefit little from current existed therapies targeting the ErbB signaling. Here, we explore the potential anti-tumor activity of Valproic acid against pancreatic cancer via targeting ErbB family members.

Methods

Cell viability assay and apoptosis evaluation were carried out to determine the efficacy of VPA on pancreatic cancer cells. Western blot analyses were performed to determine the expression and activation of proteins. Apoptosis enzyme-linked immunosorbent assay was used to quantify cytoplasmic histone associated DNA fragments. Lentiviral expression system was used to introduce overexpression of exogeneous genes or gene-targeting short hairpin RNAs (shRNAs). qRT-PCR was carried out to analyze the mRNAs and miRNAs expression levels. Tumor xenograft model was established to evaluate the in vivo anti-pancreatic cancer activity of VPA.

Results

VPA preferentially inhibited cell proliferation/survival of, and induced apoptosis in EGFR/ErbB2/ErbB3-coexpressing pancreatic cancer cells within its clinically achievable range [40~100 mg/L (0.24~0.6 mmol/L)]. Mechanistic investigations revealed that VPA treatment resulted in simultaneous significant down-regulation of EGFR, ErbB2, and ErbB3 in pancreatic cancer cells likely via induction of ErbB family members-targeting microRNAs. Moreover, the anti-pancreatic cancer activity of VPA was further validated in tumor xenograft model.

Conclusions

Our data strongly suggest that VPA may be added to the treatment regimens for pancreatic cancer patients with co-overexpression of the ErbB family members.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1160-9) contains supplementary material, which is available to authorized users.