A novel onco-miR-365 induces cutaneous squamous cell carcinoma

Micro RNA Dysregulation in Keratinocyte Carcinomas: Clinical Evidence, Functional Impact, and Future Directions

The keratinocyte carcinomas, basal cell carcinoma (BCC), and cutaneous squamous cell carcinoma (cSCC), are the most common cancers in humans. Recently, an increasing body of literature has investigated the role of miRNAs in keratinocyte carcinoma pathogenesis, progression and their use as therapeutic agents and targets, or biomarkers. However, there is very little consistency in the literature regarding the identity of and/or role of individual miRNAs in cSCC (and to a lesser extent BCC) biology. miRNA analyses that combine clinical evidence with experimental elucidation of targets and functional impact provide far more compelling evidence than studies purely based on clinical findings or bioinformatic analyses. In this study, we review the clinical evidence associated with miRNA dysregulation in KCs, assessing the quality of validation evidence provided, identify gaps, and provide recommendations for future studies based on relevant studies that investigated miRNA levels in human cSCC and BCC. Furthermore, we demonstrate how miRNAs contribute to the regulation of a diverse network of cellular functions, and that large-scale changes in tumor cell biology can be attributed to miRNA dysregulation. We highlight the need for further studies investigating the role of miRNAs as communicators between different cell types in the tumor microenvironment. Finally, we explore the clinical benefits of miRNAs as biomarkers of keratinocyte carcinoma prognosis and treatment.

Induction of RAC1 protein translation and MKK7/JNK-dependent autophagy through dicer/miR-145/SOX2/miR-365a axis contributes to isorhapontigenin (ISO) inhibition of human bladder cancer invasion

Although our previous studies have identified that isorhapontigenin (ISO) is able to initiate autophagy in human bladder cancer (BC) cells by activating JNK/C-Jun/SESN2 axis and possesses an inhibitory effect on BC cell growth, association of autophagy directly with inhibition of BC invasion has never been explored. Also, upstream cascade responsible for ISO activating JNK remains unknown. Thus, we explored both important questions in the current study and discovered that ISO treatment initiated RAC1 protein translation, and its downstream kinase MKK7/JNK phosphorylation/activation, and in turn promoted autophagic responses in human BC cells. Inhibition of autophagy abolished ISO inhibition of BC invasion, revealing that autophagy inhibition was crucial for ISO inhibition of BC invasion. Consistently, knockout of RAC1 also attenuated induction of autophagy and inhibition of BC invasion by ISO treatment. Mechanistic studies showed that upregulation of RAC1 translation was due to ISO inhibition of miR-365a transcription, which reduced miR-365a binding to the 3'-UTR of RAC1 mRNA. Further study indicated that inhibition of miR-365a transcription was caused by downregulation of its transcription factor SOX2, while ISO-promoted Dicer protein translation increased miR-145 maturation, and consequently downregulating SOX2 expression. These findings not only provide a novel insight into the understanding association of autophagy induction with BC invasion inhibition by ISO, but also identify an upstream regulatory cascade, Dicer/miR145/SOX2/miR365a/RAC1, leading to MKK7/JNKs activation and autophagy induction.

MicroRNA-365a/b-3p as a Potential Biomarker for Hypertrophic Scars

The clinical aspects of hypertrophic scarring vary according to personal constitution and body part. However, the mechanism of hypertrophic scar (HS) formation remains unclear. MicroRNAs (miRNAs) are known to contribute to HS formation, however, their detailed role remains unknown. In this study, candidate miRNAs were identified and analyzed as biomarkers of hypertrophic scarring for future clinical applications. HSfibroblasts and normal skin fibroblasts from patients were used for profiling and validation of miRNAs. An HS mouse model with xenografted human skin on nude mice was established. The miRNA expression between normal human, normal mouse, and mouse HS skin tissues was compared. Circulating miRNA expression levels in the serum of normal mice and mice with HSs were also analyzed. Ten upregulated and twenty-one downregulated miRNAs were detected. Among these, miR-365a/b-3p and miR-16-5p were identified as candidate miRNAs with statistically significant differences; miR-365a/b-3p was significantly upregulated (p = 0.0244). In mouse studies, miR-365a/b-3p expression levels in skin tissue and serum were higher in mice with HSs than in the control group. These results indicate that miRNAs contribute to hypertrophic scarring and that miR-365a/b-3p may be considered a potential biomarker for HS formation.

Molecular Mechanisms of Cutaneous Squamous Cell Carcinoma

Non-melanoma skin cancers are cutaneous malignancies representing the most common form of cancer in the United States. They are comprised predominantly of basal cell carcinomas and squamous cell carcinomas (cSCC). The incidence of cSCC is increasing, resulting in substantial morbidity and ever higher treatment costs; currently in excess of one billion dollars, per annum. Here, we review research defining the molecular basis and development of cSCC that aims to provide new insights into pathogenesis and drive the development of novel, cost and morbidity saving therapies.

CD44 Expression Intensity Marks Colorectal Cancer Cell Subpopulations with Different Extracellular Vesicle Release Capacity

Extracellular vesicles (EV) are released by virtually all cells and they transport biologically important molecules from the release site to target cells. Colorectal cancer (CRC) is a leading cause of cancer-related death cases, thus, it represents a major health issue. Although the EV cargo may reflect the molecular composition of the releasing cells and thus, EVs may hold a great promise for tumor diagnostics, the impact of intratumoral heterogeneity on the intensity of EV release is still largely unknown. By using CRC patient-derived organoids that maintain the cellular and molecular heterogeneity of the original epithelial tumor tissue, we proved that CD44^high cells produce more organoids with a higher proliferation intensity, as compared to CD44^low cells. Interestingly, we detected an increased EV release by CD44^high CRC cells. In addition, we found that the miRNA cargos of CD44^high and CD44^low cell derived EVs largely overlapped and only four miRNAs were specific for one of the above subpopulations. We observed that EVs released by CD44^high cells induced the proliferation and activation of colon fibroblasts more strongly than CD44^low cells. However, this effect was due to the higher EV number rather than to the miRNA cargo of EVs. Collectively, we identified CRC subpopulations with different EV releasing capabilities and we proved that CRC cell-released EVs have a miRNA-independent effect on fibroblast proliferation and activation.

Is miRNA Regulation the Key to Controlling Non-Melanoma Skin Cancer Evolution?

Non melanoma skin cancer (NMSC) is one of the most common types of skin cancer. It has a number of subtypes, which include basal cell carcinoma, cutaneous squamous cell carcinoma and Merkel cell carcinoma. MicroRNAs are short, non-coding RNA (ribonucleic acid) molecules, capable of regulating gene expression at a post transcriptional level. They play a pivotal role in a variety of physiologic cellular functions and pathologies, including malignant diseases. The development of miRNAs represents an important study field, which has been extensively exploited in melanoma for almost a decade with promising results, therefore we consider it a stepstone for further research projects also in non-melanoma skin cancers. The aim of our study was to explore the current literature in order to present the role of the different miRNAs in some of the most frequent types of NMSC pertaining to oncogenesis, evolution and therapy. The most relevant and accurate available data from the literature were evaluated. Our study concluded that there are almost 100 miRNAs which can be upregulated or downregulated and can play a role in oncogenesis. They can be easily identified in circulation, are stable and they can be important diagnosis/prognosis and therapy monitoring markers.

Oh, the Mutations You'll Acquire! A Systematic Overview of Cutaneous Squamous Cell Carcinoma

Nearly two million cases of cutaneous squamous cell carcinoma (cSCC) are diagnosed every year in the United States alone. cSCC is notable for both its prevalence and its propensity for invasion and metastasis. For many patients, surgery is curative. However, patients experiencing immunosuppression or recurrent, advanced, and metastatic disease still face limited therapeutic options and significant mortality. cSCC forms after decades of sun exposure and possesses the highest known mutation rate of all cancers. This mutational burden complicates efforts to identify the primary factors driving cSCC initiation and progression, which in turn hinders the development of targeted therapeutics. In this review, we summarize the mutations and alterations that have been observed in patients’ cSCC tumors, affecting signaling pathways, transcriptional regulators, and the microenvironment. We also highlight novel therapeutic opportunities in development and clinical trials.

Decreased TMEM40 expression is associated with malignant behavior of cutaneous squamous cell carcinoma and inhibits tumor progression

Cutaneous squamous cell carcinoma (CSCC) is one of the most common types of skin cancer in humans worldwide. The identification and characterization of cancer-associated transmembrane proteins are important for understanding the molecular biology of CSCC. The aim of the present study was to evaluate the expression pattern of transmembrane protein 40 (TMEM40) in CSCC and its clinical significance. The underlying mechanisms were also examined. Reverse transcription-quantitative PCR, western blot and immunohistochemistry analysis were used to determine the relative expression of TMEM40 in CSCC cell lines and clinical tissue samples. The effect of TMEM40 gene silencing on cell proliferation was also evaluated using Cell Counting Kit-8 assays. Wound healing assays, flow cytometry and Transwell assays were used to explore the migration, cell cycle distribution/apoptosis and invasion of CSCC cells following TMEM40 silencing, respectively. In the present study, increased TMEM40 expression was observed in CSCC tissue samples, compared with normal skin, and TMEM40 expression was associated with large tumor size in patients with CSCC. In vitro functional assays indicated that TMEM40 was involved in the regulation of A431 and SCL1 cell growth through its effects on the cell cycle and apoptosis. Silencing TMEM40 in A431 and SCL1 cells resulted in cell cycle arrest at the G₀/G₁ phase and promoted apoptosis. In addition, migration and invasion were significantly inhibited following silencing of TMEM40 expression in CSCC cells. Taken together, the results of the present study indicated that reduced TMEM40 expression could inhibit CSCC development and that TMEM40 may represent a therapeutic target in CSCC.

Downregulation of ARMC8 promotes tumorigenesis through activating Wnt/β-catenin pathway and EMT in cutaneous squamous cell carcinomas

BACKGROUND

Aberrant expression of Armadillo repeat containing 8 (ARMC8) plays crucial roles in tumor growth and metastasis of various cancers. The specific role of ARMC8 in cutaneous squamous cell carcinoma (cSCC) is yet to be elucidated.

OBJECTIVE

The present study aimed to investigate the molecular mechanisms of ARMC8 and epithelial-mesenchymal transition (EMT) in cSCC development and provide translational insights for future therapeutics.

METHODS

cSCC tumor specimens were used to determine the ARMC8 by immunohistochemistry. Three cSCC cell lines including HSC-1, HSC-5 and A431 as well as BALB/C mouse tumor model was utilized to study the potential mechanisms in tumorigenesis.

RESULTS

Our data identified ARMC8 as a direct downstream target of miR-664. We found that ARMC8 was remarkably low expression in cSCC patient specimens and cSCC cell lines. Knockdown of ARMC8 promotes tumorigenic behaviors such as increased cell proliferation, migration and invasion capacities in vitro and enhanced tumorigenicity in xenograft mouse model. Whereas ARMC8 over-expression inhibits tumorigenesis in cSCC. Together, it revealed ARMC8 functions as a tumor suppressor via restraining Wnt/β-catenin pathway and epithelial-mesenchymal transition in cSCC.

CONCLUSION

Our data verifies that aberrant expression of ARMC8 plays a vital role in carcinogenesis of cSCC. And overexpression of ARMC8 will facilitate future development of cSCC therapeutic interventions.

Circular RNA profiles and the potential involvement of down-expression of hsa_circ_0001360 in cutaneous squamous cell carcinogenesis

Circular RNAs (circRNAs) act as sponges of noncoding RNAs and have been implicated in many pathophysiological processes, including tumor development and progression. However, their roles in cutaneous squamous cell carcinoma (cSCC) are not yet well understood. This study aimed to identify differentially expressed circRNAs and their potential functions in cutaneous squamous cell carcinogenesis. The expression profiles of circRNAs in three paired cSCC and adjacent nontumorous tissues were detected with RNA sequencing and bioinformatics analysis. The candidate circRNAs were validated by PCR, Sanger sequencing and quantitative RT‐PCR in another five matched samples. The biological functions of circRNAs in SCL‐1 cells were assessed using circRNA silencing and overexpression, 3‐(4,5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H‐tetrazolium inner salt (MTS), flow cytometry, transwell and colony formation assays. In addition, the circRNA–miRNA–mRNA interaction networks were predicted by bioinformatics. In summary, 1115 circRNAs, including 457 up‐regulated and 658 down‐regulated circRNAs (fold change ≥ 2 and P < 0.05), were differentially expressed in cSCC compared with adjacent nontumorous tissues. Of four selected circRNAs, two circRNAs (hsa_circ_0000932 and hsa_circ_0001360) were confirmed to be significantly decreased in cSCC using PCR, Sanger sequencing and quantitative RT‐PCR. Furthermore, hsa_circ_0001360 silencing was found to result in a significant increase of the proliferation, migration and invasion but a significant decrease of apoptosis in SCL‐1 cells in vitro, whereas hsa_circ_0001360 overexpression showed the opposite regulatory effects. hsa_circ_0001360 was predicted to interact with five miRNAs and their corresponding genes. In conclusion, circRNA dysregulation may play a critical role in carcinogenesis of cSCC, and hsa_circ_0001360 may have potential as a biomarker for cSCC.

MicroRNA-365 promotes apoptosis in human melanoma cell A375 treated with hydatid cyst fluid of Echinococcus granulosus sensu stricto

Hydatid cyst fluid (HCF)-based therapeutics has experimentally targeted approaches for treating human cancer cell lines. MicroRNA-365 (miR-365) has been reported to be an important tumor suppressor miRNA in cancers. However, it remains unknown, how miR-365 plays a pivotal role in inducing apoptosis in HCF-treated cancer cells in vitro. The fertile/infertile HCF was aspirated from liver of infected sheep and in terms of molecular taxonomy was identified as G1 genotype of Echinococcus granulosus sensu stricto. A375 human melanoma cancer cells were cultured into two groups: fertile and infertile HCF-treated A375 cells. To assess the cytotoxicity of various concentrations of HCF on melanoma cells, cell viability was determined by using MTT assay. The IC50 value of HCF on A375 cells was determined 85 μg/mL. Caspase-3 enzymatic activity was evaluated by fluorometric assay in the HCF-treated melanoma cells. In addition, the mRNA expression of Bax, Bcl-2, Caspase-9 and miR-365 were determined by qRT-PCR. Findings of MTT assay showed that concentrations 85 μg/mL to 100 μg/mL of fertile HCF have the highest mortality (50%-52%) on A375 cells during 24 h. The fold change of Bax/Bcl-2 ratio, Caspase-9, miR-365 and Caspase-3 activity was higher in the fertile HCF-treated melanoma cells compared to infertile fluid treated A375 cells and human normal epithelial cell (as control cell). In conclusion, we over-expressed the miR-365 in melanoma A375 cells, via treatment of fertile HCF. Our findings suggested that inducing high expression of miR-365 might be a negative regulator of melanoma growth through activation of pro-apoptotic Bax, Caspase-9 and Caspase-3 that are essential to intrinsic apoptotic pathway. These findings provide new insights into the use of Echinococcus HCF-derived metabolites in the design of drug therapies and in vivo tumor cell vaccine to combat melanoma progression.

The Current State of Research Regarding the Role of Non-Coding RNAs in Cutaneous Squamous Cell Carcinoma

Skin cancers, including those of both both melanoma and non-melanoma subtypes, remain among the most common forms of human cancer. Non-melanoma skin cancers are typically further differentiated into the basal cell carcinoma and cutaneous squamous cell carcinoma (cSCC) categories. Current approaches to diagnosing and treating cSCC remain unsatisfactory, and the prognosis for patients with this disease is relatively poor. Recent advances in high-throughput sequencing have led to an increasingly robust understanding of the diversity of non-coding RNAs (ncRNAs) expressed in both physiological and pathological contexts. These ncRNAs include microRNAs, long ncRNAs, and circular RNAs, all of which have been found to play key functional roles and/or to have value as diagnostic biomarkers or therapeutic targets in a range of different disease contexts. The number of ncRNAs associated with cSCC continues to rise, and as such, there is clear value in comprehensively reviewing the functional roles of these molecules in this form of cancer in order to highlight future avenues for research and clinical development.

Importance of microRNAs in Skin Oncogenesis and Their Suitability as Agents and Targets for Topical Therapy

Skin cancer is the most common cancer worldwide, with rapidly increasing incidence and consistent mortality. Skin cancer encompasses melanoma and non-melanoma skin cancer, which in turn is mainly divided into cutaneous squamous cell carcinoma and basal cell carcinoma. Small noncoding micro-RNAs (miRNAs) regulate protein expression after transcription and play a role in the development and progression of skin cancer. Deregulated expression of miRNAs in skin cancer is associated with cell proliferation, angiogenesis, metastasis, apoptosis, immune response, and drug resistance. Specific patterns of miRNAs in specific skin cancer types can be used as diagnostic markers. For therapeutic purposes, both miRNA and chemically modified variants thereof as well as miRNA antagonists (antagomiRs) or RNA inhibitors may be applied topically. Due to their specific physicochemical properties, physical or chemical diffusion promoters are used with varying degrees of success. There is no question by now that such preparations have a high potential for the treatment of epithelial skin tumors in particular.

Downregulation of miR-10a inhibits cutaneous squamous cell carcinoma cell proliferation, migration, and invasion by targeting Syndecan-1

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is a malignancy of epidermal keratinocytes which accounts for approximately one-third of skin cancer-related death yearly. In this study, we aim to investigate the mechanism of miR-10a in regulating cellular function of cSCC cells and its possible role in prognosis of cSCC.

METHODS

The expression of miR-10a was detected by qRT-PCR. Target mRNA candidates were detected by bioinformatic analysis. Proliferative and migration capability of cSCC cell were examined by MTT assay, wound healing assay, and invasion assay, respectively. miR-10a expression was monitored in cSCC patients to elucidate the relationship between miR-10a expression and outcomes of cSCC.

RESULTS

In our study, we found that expression of miR-10a was significantly down-regulated in cSCC cell in vitro and in vivo. Moreover, our results revealed that SDC-1 was a likely target of miR-10a in regulating biologic function of cSCC cell. Additionally, miR-10a expression level was inversely correlated with cSCC cell differentiation and tumor progression.

CONCLUSION

These findings in this study indicate the importance of miR-10a in cSCC cell hallmarks and its use as a novel target for cSCC treatment.

miR-365 (microRNA): Potential Biomarker in Oral Squamous Cell Carcinoma Exosomes and Extracellular Vesicles

Introduction: miR-365 is a non-coding microRNA that regulates transcription and has been demonstrated to promote oncogenesis and metastasis in some cancers, while suppressing these effects in others. Many microRNAs are produced and then exported extracellularly in exosomes, which are small extracellular vesicles ranging from 30 to 100 nm that are found in eukaryotic fluids and facilitate many cellular functions. Exosomes and extracellular vesicles are produced by many cell types, including oral cancer cells—although no study to date has evaluated miR-365 and oral cancer exosomes or extracellular vesicles. Based on this information, our research question was to evaluate whether oral cancers produce exosomes or extracellular vesicles containing miR-365. Materials and Methods: Two commercially available oral cancer cell lines (SCC25 and CAL27) and a normal oral keratinocyte (OKF4) were grown in serum-free media, supplemented with exosome-depleted fetal bovine serum. Extracellular vesicles and exosomes were then isolated using the Invitrogen total exosome RNA and protein isolation kit for processing using the hsa-miR-365a-5p microRNA qPCR assay kit. Results: RNA was successfully isolated from the exosome-depleted supernatant from each cell line—SCC9, SCC15, SCC25, and CAL27 (oral squamous cell carcinomas) and OKF4 (oral epithelial cell line). Relative concentrations of RNA were similar among each cell line, which were not significantly different, p = 0.233. RNA quality was established by A260:A280 absorbance using a NanoDrop, revealing purity ranging 1.73–1.86. Expression of miR-16 was used to confirm the presence of microRNA from the extracted exosomes and extracellular vesicles. The presence of miR-365 was then confirmed and normalized to miR-16 expression, which demonstrated an increased level of miR-365 in both CAL27 and SCC25. In addition, the normalized relative quantity (RQ) for miR-365 exhibited greater variation among SCC25 (1.382–4.363) than CAL27 cells (1.248–1.536). Conclusions: These results confirm that miR-365 is not only expressed in oral cancer cell lines, but also is subsequently exported into exosomes and extracellular vesicles derived from these cultures. These data may help to contextualize the potential for this microRNA to contribute to the phenotypes and behaviors of oral cancers that express this microRNA. Future research will begin to investigate these potential mechanisms and pathways and to determine if miR-365 may be useful as an oral cancer biomarker for salivary or liquid biopsies.

Overexpressed GATA3 enhances the sensitivity of colorectal cancer cells to oxaliplatin through regulating MiR-29b

Background

GATA binding protein 3 (GATA3) and miR-29b are related to colorectal cancer (CRC). The current study explored the regulatory relationship between GATA3 and miR-29b, and the mechanism of the two in the drug resistance of CRC cells to oxaliplatin.

Method

Apoptosis of CRC cells induced by oxaliplatin at various doses was detected by flow cytometry. CRC cells were separately transfected with overexpression and knockdown of GATA3, miR-29b agomir and antagomir, and treated by oxaliplatin to detect the cell viability and apoptosis by performing Cell Couting Kit-8 (CCK-8) and flow cytometry. The expression levels of GATA3, caspase3 and cleaved caspase3 were determined by Western blot, and the expression of miR-29b was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Animal experiments were performed to examine the changes of transplanted tumors in nude mouse xenograft studies and observed by in vivo imaging. TUNEL staining was performed to detect tumor cell apoptosis.

Result

Both GATA3 and miR-29b agomir inhibited the activity of the CRC cells, promoted apoptosis and Cleaved caspase3 expression, and reduced the resistance of the cells to chemotherapy drug oxaliplatin. Although GATA3 could up-regulate miR-29b expression, the tumor-suppressive effect of GATA3 was partially reversed by miR-29b antagomir. In vivo experiments showed that down-regulating the expression of GATA3 promoted the growth rate and volume of transplanted tumors, while overexpressing GATA3 had no significant effect on tumor growth. TUNEL staining results showed that knocking down or overexpression of GATA3 did not cause significant changes to apoptotic bodies of CRC cells, while oxaliplatin treatment increased the number of apoptotic bodies.

Conclusion

GATA3 inhibits the cell viability of CRC cells, promotes apoptosis, and reduces oxaliplatin resistance of CRC cells through regulating miR-29b.

miR-27a Downregulation Promotes Cutaneous Squamous Cell Carcinoma Progression via Targeting EGFR

Cutaneous squamous cell carcinoma (cSCC) is the second common malignant cancer around the worldwide and is etiologically linked to ultraviolet radiation. miRNAs play an important role in the initiation and progression of cancers. However, the functions of miRNAs in cSCC remain to be elucidated. Here, we screened and identified miR-27a as a consistently downregulated miRNA after UVB irradiation in HaCaT cells. It was found that miR-27a expression was significantly decreased in cSCC cells and tissues. in vitro and in vivo experiments showed that miR-27a inhibited cell proliferation and invasion of cSCC cells. Mechanistically, EGFR was identified to be directly targeted by miR-27a and miR-27a suppressed the phosphorylation of EGFR and its downstream NF-κB signaling pathway. Overall, these findings suggest that downregulation of miR-27a promotes tumor growth and metastasis via targeting EGFR and its downstream NF-κB signaling pathway, reminding that miR-27a plays a vital role in the progression of cSCC and could be a new therapeutic target.

Cyclic tensile strain promotes chondrogenesis of bone marrow-derived mesenchymal stem cells by increasing miR-365 expression

AIMS

The chondrogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) is critical for cartilage regeneration. Tissues constructed from BMSCs through cartilage tissue engineering still exhibit some histological, morphological, and biomechanical differences from normal cartilage tissues. Cyclic tensile strain (CTS) can increase chondrogenic gene expression and reduce hypertrophic gene expression in chondrocytes. miR-365 has been identified as a mechanoresponsive microRNA and is an important regulator of both chondrocyte hypertrophy and differentiation. Therefore, we hypothesized that CTS may promote the chondrogenesis of BMSCs by upregulating the expression of miR-365.

METHODS

BMSCs were subjected to CTS to investigate the effects and mechanism on chondrogenesis. An Agilent miRNA microarray was used to profile miRNAs in the CTS-treated BMSCs and 3D-cultured control BMSCs. miR-365 was shown to interact with HDAC4 mRNA through a luciferase reporter assay. An animal cartilage defect model was constructed and different groups of BMSCs were implanted to investigate their in vivo effect.

KEY FINDINGS

CTS promoted BMSC chondrogenesis. miR-365 was significantly upregulated in CTS-treated cells and played an important role in CTS-mediated chondrogenesis. Luciferase assays showed that HDAC4 is a direct target of miR-365. An in vivo study showed that CTS treatment and miR-365 overexpression could promote cartilage regeneration from BMSCs.

SIGNIFICANCE

CTS can promote the expression of miR-365, a crucial mechanosensitive microRNA involved in the chondrogenesis of BMSCs, which directly inhibits the expression of HDAC4, in turn, enhancing the chondrogenesis of BMSCs.

MicroRNA Dysregulation in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans and it can be locally invasive and metastatic to distant sites. MicroRNAs (miRNAs or miRs) are endogenous, small, non-coding RNAs of 19–25 nucleotides in length, that are involved in regulating gene expression at a post-transcriptional level. MicroRNAs have been implicated in diverse biological functions and diseases. In cancer, miRNAs can proceed either as oncogenic miRNAs (onco-miRs) or as tumor suppressor miRNAs (oncosuppressor-miRs), depending on the pathway in which they are involved. Dysregulation of miRNA expression has been shown in most of the tumors evaluated. MiRNA dysregulation is known to be involved in the development of cutaneous squamous cell carcinoma (CSCC). In this review, we focus on the recent evidence about the role of miRNAs in the development of CSCC and in the prognosis of this form of skin cancer.

MicroRNA-365 targets multiple oncogenes to inhibit proliferation, invasion, and self-renewal of aggressive endometrial cancer cells

Background

MicroRNA-365 (miR-365) has been reported to be a tumor suppressor miRNA. However, the role of miR-365 in progression of endometrial cancer (EC) has not been explored, in this study, we have found that re-expression of miRNA-365 inhibits cell proliferation, causes apoptosis and senescence.

Materials and methods

Overexpression of miR-365 attenuated cell migration and invasion, inhibited sphere-forming capacity, and enhanced the chemosensitivity to paclitaxel. In silico prediction tools identified the potential targets of miR-365.

Results

We identified EZH2 and FOS as targets of miR-365 and found that downregulating these genes imitated the tumor suppressive effect of miR-365. The outcomes of the study suggested that a reverse correlation existed between low miR-365 and overexpression of FOS and EZH2 in EC tissue specimens.

Conclusion

The study concludes that miR-365 acts as an important tumor suppressor and contributes by suppressing cell invasiveness, proliferation, and self-renewal in cancer cell lines by regulating multiple oncogenes. We establish that miR-365-EZH2/FOS pathway is an important target for treating EC.

Transfer of miRNA in Macrophage-Derived Exosomes Induces Drug Resistance in Pancreatic Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is known for its resistance to gemcitabine, which acts to inhibit cell growth by termination of DNA replication. Tumor-associated macrophages (TAM) were recently shown to contribute to gemcitabine resistance; however, the exact mechanism of this process is still unclear. Using a genetic mouse model of PDAC and electron microscopy analysis, we show that TAM communicate with the tumor microenvironment via secretion of approximately 90 nm vesicles, which are selectively internalized by cancer cells. Transfection of artificial dsDNA (barcode fragment) to murine peritoneal macrophages and injection to mice bearing PDAC tumors revealed a 4-log higher concentration of the barcode fragment in primary tumors and in liver metastasis than in normal tissue. These macrophage-derived exosomes (MDE) significantly decreased the sensitivity of PDAC cells to gemcitabine, in vitro and in vivo This effect was mediated by the transfer of miR-365 in MDE. miR-365 impaired activation of gemcitabine by upregulation of the triphospho-nucleotide pool in cancer cells and the induction of the enzyme cytidine deaminase; the latter inactivates gemcitabine. Adoptive transfer of miR-365 in TAM induced gemcitabine resistance in PDAC-bearing mice, whereas immune transfer of the miR-365 antagonist recovered the sensitivity to gemcitabine. Mice deficient of Rab27 a/b genes, which lack exosomal secretion, responded significantly better to gemcitabine than did wildtype. These results identify MDE as key regulators of gemcitabine resistance in PDAC and demonstrate that blocking miR-365 can potentiate gemcitabine response.Significance: Harnessing macrophage-derived exosomes as conveyers of antagomiRs augments the effect of chemotherapy against cancer, opening new therapeutic options against malignancies where resistance to nucleotide analogs remains an obstacle to overcome. Cancer Res; 78(18); 5287-99. ©2018 AACR.

MicroRNA-365 Inhibits Cell Growth and Promotes Apoptosis in Melanoma by Targeting BCL2 and Cyclin D1 (CCND1)

BACKGROUND MicroRNA-365 (miR-365) is involved in the development of a variety of cancers. However, it remains largely unknown if and how miRNAs-365 plays a role in melanoma development. MATERIAL AND METHODS In this study, we overexpressed miR-365 in melanoma cell lines A375 and A2058, via transfection of miR-365 mimics oligos. We then investigated alterations in a series of cancer-related phenotypes, including cell viability, cell cycle, apoptosis, colony formation, and migration and invasion capacities. We also validated cyclin D1 (CCND1) and BCL2 apoptosis regulator (BCL2) as direct target genes of miR-365 by luciferase reporter assay and investigated their roles in miR-365 caused phenotypic changes. To get a more general view of miR-365's biological functions, candidate target genes of miR-365 were retrieved via searching online databases, which were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses for potential biological functions. We then analyzed The Cancer Genome Atlas (TCGA) Skin Cutaneous Melanoma (SKCM) dataset for correlation between miR-365 level and clinicopathological features of patients, and for survival of patients with high and low miR-365 levels. RESULTS We found that miR-365 was downregulated in melanoma cells. Overexpression of miR-365 remarkably suppressed cell proliferation, induced cell cycle arrest and apoptosis, and compromised the migration and invasion capacities in A375 and A2058 cell lines. We also found that the phenotypic alterations by miR-365 were partially due to downregulation of CCND1 and BCL2 oncogenes. The bioinformatics analysis revealed that predicted targets of miR-365 were widely involved in transcriptional regulation and cancer-related signaling pathways. However, analysis of SKCM dataset failed to find differences in miR-365 level among melanoma patients at different clinicopathologic stages. The Kaplan-Meier analysis also failed to discover significant differences in overall survival and disease-free survival between patients with high and low miR-365 levels. CONCLUSIONS Our findings suggested that miR-365 might be an important novel regulator for melanoma formation and development, however, the in vivo roles in melanoma developments need further investigation.

MicroRNA-365 promotes lung carcinogenesis by downregulating the USP33/SLIT2/ROBO1 signalling pathway

Background

Abnormal microRNA expression is closely related to cancer occurrence and development. miR-365a-3p plays an oncogenic role in skin cancer, but its role in lung cancer remains unclear. In this study, we aimed to investigate its role and underlying molecular mechanisms in lung cancer.

Methods

Western blot and real-time quantitative PCR (qPCR) were used to detect the expression of miR-365a-3p in lung adenocarcinoma and lung cancer cell lines. The effects of miR-365a-3p on lung cancer cell proliferation, migration, and invasion were also explored in vitro. The potential miR-365a-3p that targets USP33 was determined by dual luciferase reporter assay and verified by qPCR and western blot analysis. miR-365a-3p acts as an oncogene by promoting lung carcinogenesis via the downregulation of the miR-365a/USP33/SLIT2/ROBO1 axis based on western blot analysis. Subcutaneous tumourigenesis further demonstrated that miR-365a-3p promotes tumour formation in vivo.

Results

miR-365a-3p was upregulated in lung adenocarcinoma and lung cancer cell lines. Overexpression of miR-365a-3p promoted and inhibition of miR-365a-3p suppressed the proliferation, migration, and invasion of lung cancer cells. We identified USP33 as the downstream target of miR-365a-3p and observed a negative correlation between miR-365a-3p and USP33 expression in lung adenocarcinoma patients. The miR-365/USP33/SLIT2/ROBO1 axis, a new mechanism, was reported to inhibit the invasion and metastasis of lung cancer. A nude mouse model of lung cancer further verified these findings.

Conclusions

In summary, miR-365a-3p acts as an oncogene by promoting lung carcinogenesis via the downregulation of the USP33/SLIT2/ROBO1 signalling pathway, making the miR-365/USP33/SLIT2/ROBO1 axis a new mechanism of lung cancer promotion and a novel therapeutic target for predicting prognosis and response to gene therapy.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0563-6) contains supplementary material, which is available to authorized users.

HOXA9 inhibits HIF-1α-mediated glycolysis through interacting with CRIP2 to repress cutaneous squamous cell carcinoma development

Glycolytic reprogramming is a typical feature of many cancers; however, key regulators of glucose metabolism reengineering are poorly understood, especially in cutaneous squamous cell carcinoma (cSCC). Here, Homeobox A9 (HOXA9), a direct target of onco-miR-365, is identified to be significantly downregulated in cSCC tumors and cell lines. HOXA9 acts as a tumor suppressor and inhibits glycolysis in cSCC in vitro and in vivo by negatively regulating HIF-1α and its downstream glycolytic regulators, HK2, GLUT1 and PDK1. Mechanistic studies show that HOXA9-CRIP2 interaction at glycolytic gene promoters impeds HIF-1α binding, repressing gene expression in trans. Our results reveal a miR-365-HOXA9-HIF-1α regulatory axis that contributes to the enhanced glycolysis in cSCC development and may represent an intervention target for cSCC therapy.

Hypoxia-inducible transcription factor HIF-1α promotes glycolysis allowing cell survival under stress. Here the authors show, using both cell lines and animal models, that in cutaneous squamous cell carcinoma HOXA9 acts as a tumor suppressor and inhibits glycolysis by associating with CRIP2 to repress HIF-1α binding to target genes.

MicroRNA-365 alleviates morphine analgesic tolerance via the inactivation of the ERK/CREB signaling pathway by negatively targeting β-arrestin2

BACKGROUND

Morphine is widely used in clinical practice for a class of analgesic drugs, long-term use of morphine will cause the action of tolerance. MicroRNAs have been reported to be involved in morphine analgesic tolerance..

METHODS

Forty male SD rats were selected and randomly divided into 5 groups: the control group, morphine tolerance group, miR-365 mimic + morphine (miR-365 mimic) group, miR-365 inhibitor + morphine (miR-365 inhibitor) group and miR-365 negative control (NC) + morphine (miR-365 NC) group. After the administration of morphine at 0 d, 1 d, 3 d, 5 d and 7 d, behavioral testing was performed. A dual luciferase reporter gene assay was performed to confirm the relationship between miR-365 and β-arrestin2, RT-qPCR was used to detect miR-365, β-arrestin2, ERK and CREB mRNA expressions, western blotting was used to evaluate the protein expressions of β-arrestin2, ERK, p-ERK, CREB and p-CREB, ELISA was used to detect the contents of IL-1β, TNF-α and IL-18, while immunofluorescence staining was used to measure the GFAP expression. Intrathecal injection of mir365 significantly increased the maximal possible analgesic effect (%MPE) in morphine tolerant rats. β-arrestin2 was the target gene of miR-365.

RESULTS

The results obtained showed that when compared with the morphine tolerance group, there was an increase in miR-365 expression and a decrease in the β-arrestin2, ERK, CREB protein expressions, contents of IL-1β, TNF-α, IL-18 and GFAP expression in the miR-365 mimic group, while the miR-365 inhibitor group displayed an opposite trend.

CONCLUSIONS

The results of this experiment suggest that by targeting β-arrestin2 to reduce the contents of IL-1β, TNF-α and IL-18 and by inhibiting the activation of ERK/CREB signaling pathway, miR-365 could lower morphine analgesic tolerance.

The microRNA landscape of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is a keratinocyte-derived skin tumor. It is the second-most-common cancer affecting the Caucasian population and is responsible for >20% of all skin-cancer-related deaths. The estimated incidence of non-melanoma skin cancer in the USA is >1000000 cases per year, of which roughly 20-30% are squamous cell carcinoma. To better understand and treat this challenging cancer, current research focuses on development of novel strategies to improve the understanding of tumor biogenesis on an individual basis. microRNAs are becoming important biomarkers in the diagnosis, prognosis and treatment of cSCC. This review describes the current knowledge on miRNA expression in cSCC and its role as a biomarker for personalized medicine.

miR-365 functions as a tumor suppressor by directly targeting CYR61 in osteosarcoma

Increasing evidence indicates that microRNAs(miRNAs) are often aberrantly expressed in osteosarcoma (OS) and play critical roles in OS tumorigenesis. Therefore, the discovery of miRNAs may provide a new and powerful tool for understanding the mechanismof OS initiation and development. The aim of this study was to investigate the functional significance of miR-365 and identify its possible mechanism in OS cells. Here, wefound that the expression level of miR-365 is significantly downregulated in OS tissues and cell lines, and its expression isassociated with the clinical stage, distant metastasis, tumor grade, and poor overall survival rate. The overexpression of miR-365 is able to inhibit cell proliferation, migration, and invasion in Saos-2 and MG-63 cells. Moreover, the cysteine-rich angiogenic inducer 61 (CYR61) has been identified as a target of miR-365 in OS cells, and its expression is found to be significantly increased in OS tissues, which is negatively correlated with miR-365. Furthermore, CYR61 overexpression significantly attenuated the suppressive effects of miR-365 on the proliferation, migration, and invasion of Saos-2 and MG-63 cells. Therefore, we consider that miR-365 acts as a tumor suppressor in OS, partly, by targeting CYR61 expression.

MicroRNA-365 regulates IL-1β-induced catabolic factor expression by targeting HIF-2α in primary chondrocytes

Endothelial Per-Arnt-Sim domain protein-1/hypoxia-inducible factor-2α (EPAS-1/ HIF-2α) is a catabolic transcription factor that regulates osteoarthritis (OA)-related cartilage destruction. Here, we examined whether microRNA-365 (miR-365) affects interleukin (IL)-1β-induced expression of catabolic factors in chondrocytes via regulation of HIF-2α. MiR-365 levels were significantly decreased in human OA cartilage relative to normal cartilage. Overexpression of miR-365 significantly suppressed IL-1β-induced expression of HIF-2α in human articular chondrocytes. Pharmacological inhibition of various IL-1β-associated signaling pathways revealed mitogen-activated protein kinase and nuclear factor-κB as the primary pathways driving IL-1β-mediated decreases in miR-365 and subsequent increase in HIF-2α expression. Using a luciferase reporter assay encoding the 3′ untranslated region (UTR) of human HIF-2α mRNA, we showed that overexpression of miR-365 significantly suppressed IL-1β-induced up-regulation of HIF-2α. AGO2 RNA-immunoprecipitation (IP) assay demonstrated that miR-365 and HIF-2α mRNA were enriched in the AGO2-IP fraction in miR-365-transfected primary chondrocytes compared to miR-con-transfected cells, indicating that HIF-2α is a target of miR-365. Furthermore, miR-365 overexpression significantly suppressed IL-1β-induced expression of catabolic factors, including cyclooxygenase-2 and matrix metalloproteinase-1, -3 and -13, in chondrocytes. In pellet culture of primary chondrocytes miR-365 prevented IL-1β-stimulated extracellular matrix loss and matrix metalloproteinase-13 expression. MiR-365 regulates IL-1β-stimulated catabolic effects in human chondrocytes by modulating HIF-2α expression.

Loss of BAX by miR-365 Promotes Cutaneous Squamous Cell Carcinoma Progression by Suppressing Apoptosis

Pro-apoptotic BCL2 associated X (BAX) is traditionally thought to be regulated by anti-apoptotic BCL-2 family members, like BCL2-like 1 (BCL-XL), at the protein level. However, the posttranscriptional regulation of BAX is under explored. In this study, we identified BAX as the novel downstream target of miR-365, which is supported by gain- and loss-of-function studies of onco-miR-365. Loss of BAX by either RNA interference or highly-expressed miR-365 in cells of cutaneous squamous cell carcinoma (CSCC) enhanced the tumor resistance against apoptosis, while repressing cell proliferation, migration, and invasiveness. In vivo experiment confirmed that BAX knockdown promotes the growth of CSCC xenografts. Collectively, our results find a miR-365-BAX axis for alleviating the pro-apoptotic effects of BAX, which promotes CSCC development and may facilitate the generation of novel therapeutic regimens to the clinical treatment of CSCC.

Novel mechanism of miRNA-365-regulated trophoblast apoptosis in recurrent miscarriage

Clinical pregnancies increasingly end in recurrent miscarriage (RM) during the first trimester, with genetic factors shouldering the main responsibility. MicroRNAs (miRNAs) regulate gene expression in a wide array of important biological processes. We examined the potential role of dysregulated miRNAs in RM pathogenesis and trophoblast development as an approach to elucidate the molecular mechanism behind RM. miRNA profiles from clinical specimens of RM and induced abortion (IA) were compared, and several miRNAs were found to be aberrantly expressed in RM samples. Among the miRNAs, miR-365 was significantly differentially expressed in RM decidual tissues. Furthermore, our results demonstrate that miR-365 functions as an upstream regulator of MDM2/p53 expression, cell cycle progression and apoptosis in trophoblasts. Bioinformatic prediction and experimental validation assays identified SGK1 as a direct target of miR-365; consistently, its protein levels were low in decidual tissues. Additionally, functional studies revealed that SGK1 silencing elicits cell cycle arrest and apoptosis in trophoblasts and that SGK1 overexpression attenuates the effects of miR-365 on apoptosis and MDM2/p53 expression. Collectively, our data provide evidence that the up-regulation of miR-365 may contribute to RM by decreasing SGK1 expression, which suggests its potential utility as a prognostic biomarker and therapeutic target for RM.

miR-365 targets ADAM10 and suppresses the cell growth and metastasis of hepatocellular carcinoma

Expression of miR-365 has been reported to be downregulated in hepatocellular carcinoma (HCC). However, the biological function and underlying mechanism of miR-365 in HCC growth and metastasis remain unclear. The aim of the present study was to explore the role of miR-365 in HCC progression. We found that miR-365 expression was downregulated in HCC tissues and cell lines. Further results showed that low expression of miR-365 was significantly associated with tumor-node-metastasis (TNM) stage and lymph node metastasis. Functional assays revealed that overexpression of miR-365 significantly inhibited cell proliferation, colony formation, migration and invasion of HCC cells in vitro, and suppressed tumor growth in vivo. Mechanistic investigations demonstrated that ADAM10 (a disintegrin and metalloproteinase 10) is a target of miR-365 in HCC. In addition, knockdown of ADAM10 in HepG2 cells significantly inhibited cell proliferation, colony formation, migration and invasion, which mimicked the suppressive effects induced by miR-365 overexpression. Restoration of ADAM10 expression partially reversed the suppressive effects mediated by miR-365 overexpression. Taken together, these results indicate that miR-365 functions as a tumor-suppressor in HCC through targeting ADAM10, and may serve as a promising candidate for therapeutic applications in HCC treatment.

Association of Polymorphisms in three pri-miRNAs that Target Pepsinogen C with the Risk and Prognosis of Gastric Cancer

We aimed to explore the associations of polymorphisms in three microRNAs (miRNAs) (let-7e rs8111742, miR-365b rs121224 and miR-4795 rs1002765) that target PGC with the risk and prognosis of gastric cancer/atrophic gastritis. Sequenom’s MassArray was used to genotype the miRNA polymorphisms in 724 gastric cancer cases, 862 atrophic gastritis cases and 862 controls in a Chinese population. We found that let-7e rs8111742 and miR-4795 rs1002765 were associated with the risk of gastric cancer in the H. pylori-positive subgroup. MiR-365b rs121224 was associated with the risk of intestinal-type gastric cancer in the alcohol consumption subgroup. Intestinal-type gastric cancer patients at Borrmann stages III-IV who carry the miR-365b rs121224 GG genotype had better prognosis compared with those who carry the CG or CC genotypes. MiR-365b rs121224 was associated with Lauren typing and TNM staging, in which the distribution of GG genotype carriers in intestinal-type gastric cancer and the TNM stage I-II subgroup was higher than that of CG or CC genotypes, which contrasted with the distribution in diffuse-type gastric cancer or TNM III-IV groups. These findings suggested that the polymorphisms in these miRNAs might be biomarkers for gastric cancer risk and prognosis, especially for populations infected with Helicobacter pylori or who consume alcohol.

MicroRNA-31 functions as an oncogenic microRNA in cutaneous squamous cell carcinoma cells by targeting RhoTBT1

Cutaneous squamous cell carcinoma (cSCC) is a malignancy of epidermal keratinocytes that is responsible for ~20% of annual skin cancer-associated mortalities. Accumulating evidence demonstrates that the dysregulation of micro (mi)RNAs serves a significant role in the tumorigenesis and progression of human cSCC. MicroRNA-31 (miR-31) is upregulated in cSCC and is involved in cSCC development. However, the underlying mechanism remains unclear. The present study demonstrated that miR-31 is upregulated in the cSCC cell line, A-431, and that miR-31 expression contributes to the cell proliferation and invasion of cSCC. In addition, bioinformatics combined with dual luciferase reporter analysis was applied to determine that the tumor suppressor RhoTBT1 was a direct target of miR-31. In addition, miR-31 mimics reduced RhoBTB1 expression in A-431 cells. The results of MTT and Transwell assays demonstrated that knockdown of RhoBTB1 by short interfering RNA induced cell proliferation and invasion in A-431 cells. These results indicated that suppression of RhoBTB1 may be involved in cSCC tumorigenesis, which was directly affected by miR-31. In conclusion, the present study provides evidence that miR-31 acts as an oncogene through direct repression of RhoTBT1 expression in cSCC cancer, suggesting a potential application of miR-31 in prognosis prediction and its therapeutic application in cSCC.

MicroRNA-365 inhibits ovarian cancer progression by targeting Wnt5a

MicroRNA-365 (miR-365) has been reported to play an important role in tumorigenesis in many types of cancers; however, the role of miR-365 in the carcinogenesis of ovarian cancer remains unknown. In this study, we focused on the roles and underlying mechanisms of miR-365 in ovarian cancer. Here, we found that miR-365 expression level was significantly decreased in ovarian cancer tissues and cell lines, and that low miR-365 expression was negatively significantly associated with advanced stages as defined by the International Federation of Gynecology and Obstetrics (FIGO), histological grading, and lymph node metastasis. Further functional assays showed that transfection with a miR-365 mimic significantly decreased ovarian cancer cell proliferation, colony formation, migration, and invasion. In addition, Wnt5a was identified as a target gene of miR-365 in ovarian cancer by bioinformatic analysis, luciferase reporter assay, qPCR, and western blot. Wnt5a expression levels were upregulated and inversely correlated with miR-365 expression in ovarian cancer tissues (r = -0.638, P < 0.0001). Overexpression of Wnt5a could effectively reverse the miR-365 overexpression-induced suppression of proliferation and invasion in ovarian cancer cells. Additionally, in vivo studies utilizing a xenograft model demonstrated that overexpression of miR-365 could reduce tumor growth by repressing Wnt5a. Taken together, these findings suggest that miR-365 may be a promising candidate for therapeutic application in ovarian cancer treatment.

Exploring the intrinsic differences among breast tumor subtypes defined using immunohistochemistry markers based on the decision tree

Exploring the intrinsic differences among breast cancer subtypes is of crucial importance for precise diagnosis and therapeutic decision-making in diseases of high heterogeneity. The subtypes defined with several layers of information are related but not consistent, especially using immunohistochemistry markers and gene expression profiling. Here, we explored the intrinsic differences among the subtypes defined by the estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 based on the decision tree. We identified 30 mRNAs and 7 miRNAs differentially expressed along the tree's branches. The final signature panel contained 30 mRNAs, whose performance was validated using two public datasets based on 3 well-known classifiers. The network and pathway analysis were explored for feature genes, from which key molecules including FOXQ1 and SFRP1 were revealed to be densely connected with other molecules and participate in the validated metabolic pathways. Our study uncovered the differences among the four IHC-defined breast tumor subtypes at the mRNA and miRNA levels, presented a novel signature for breast tumor subtyping, and identified several key molecules potentially driving the heterogeneity of such tumors. The results help us further understand breast tumor heterogeneity, which could be availed in clinics.

MiR-204 silencing in intraepithelial to invasive cutaneous squamous cell carcinoma progression

Background

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer and frequently progresses from an actinic keratosis (AK), a sun-induced keratinocyte intraepithelial neoplasia (KIN). Epigenetic mechanisms involved in the phenomenon of progression from AK to cSCC remain to be elicited.

Methods

Expression of microRNAs in sun-exposed skin, AK and cSCC was analysed by Agilent microarrays. DNA methylation of miR-204 promoter was determined by bisulphite treatment and pyrosequencing. Identification of miR-204 targets and pathways was accomplished in HaCat cells. Immunofluorescence and immunohistochemistry were used to analyze STAT3 activation and PTPN11 expression in human biopsies.

Results

cSCCs display a marked downregulation of miR-204 expression when compared to AK. DNA methylation of miR-204 promoter was identified as one of the repressive mechanisms that accounts for miR-204 silencing in cSCC. In HaCaT cells miR-204 inhibits STAT3 and favours the MAPK signaling pathway, likely acting through PTPN11, a nuclear tyrosine phosphatase that is a direct miR-204 target. In non-peritumoral AK lesions, activated STAT3, as detected by pY705-STAT3 immunofluorescence, is retained in the membrane and cytoplasm compartments, whereas AK lesions adjacent to cSCCs display activated STAT3 in the nuclei.

Conclusions

Our data suggest that miR-204 may act as a “rheostat” that controls the signalling towards the MAPK pathway or the STAT3 pathway in the progression from AK to cSCC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-016-0537-z) contains supplementary material, which is available to authorized users.

miR-199a-5p induces cell invasion by suppressing E-cadherin expression in cutaneous squamous cell carcinoma

A growing quantity of evidence exists to suggest that microRNAs are significant regulators of multiple cellular processes. When expressed aberrantly in different types of cancer, including cutaneous squamous cell carcinoma (cSCC), they play key roles in tumorigenesis and progression. The aberrant expression of miR-199a-5p has been observed to contribute to carcinogenesis in various types of cancer. However, the role of miR-199a-5p in the progression of cSCC metastasis remains largely unknown. In this study, we determined that miR-199a-5p was the upstream regulator of CDH1 (E-cadherin) and that it could suppress the expression of E-cadherin in cSCC cells. In addition, miR-199a-5p mimics significantly induced cell invasion and the activity of matrix metalloproteinase (MMP)2 and MMP9 in cSCC cells. In conclusion, these results are likely to aid in elucidating the molecular mechanisms of cSCC progression. In addition, the findings provide a new theoretical basis to further investigate miR-199a-5p as a potential biomarker and a promising approach in cSCC treatment.

Profilings of MicroRNAs in the Liver of Common Carp (Cyprinus carpio) Infected with Flavobacterium columnare

MicroRNAs (miRNAs) play important roles in regulation of many biological processes in eukaryotes, including pathogen infection and host interactions. Flavobacterium columnare (FC) infection can cause great economic loss of common carp (Cyprinus carpio) which is one of the most important cultured fish in the world. However, miRNAs in response to FC infection in common carp has not been characterized. To identify specific miRNAs involved in common carp infected with FC, we performed microRNA sequencing using livers of common carp infected with and without FC. A total of 698 miRNAs were identified, including 142 which were identified and deposited in the miRbase database (Available online: http://www.mirbase.org/) and 556 had only predicted miRNAs. Among the deposited miRNAs, eight miRNAs were first identified in common carp. Thirty of the 698 miRNAs were differentially expressed miRNAs (DIE-miRNAs) between the FC infected and control samples. From the DIE-miRNAs, seven were selected randomly and their expression profiles were confirmed to be consistent with the microRNA sequencing results using RT-PCR and qRT-PCR. In addition, a total of 27,363 target genes of the 30 DIE-miRNAs were predicted. The target genes were enriched in five Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, including focal adhesion, extracellular matrix (ECM)-receptor interaction, erythroblastic leukemia viral oncogene homolog (ErbB) signaling pathway, regulation of actin cytoskeleton, and adherent junction. The miRNA expression profile of the liver of common carp infected with FC will pave the way for the development of effective strategies to fight against FC infection.

MiRNA Transcriptome Profiling of Spheroid-Enriched Cells with Cancer Stem Cell Properties in Human Breast MCF-7 Cell Line

Breast cancer is the second leading cause of cancer-related mortality worldwide as most patients often suffer cancer relapse. The reason is often attributed to the presence of cancer stem cells (CSCs). Recent studies revealed that dysregulation of microRNA (miRNA) are closely linked to breast cancer recurrence and metastasis. However, no specific study has comprehensively characterised the CSC characteristic and miRNA transcriptome in spheroid-enriched breast cells. This study described the generation of spheroid MCF-7 cell in serum-free condition and the comprehensive characterisation for their CSC properties. Subsequently, miRNA expression differences between the spheroid-enriched CSC cells and their parental cells were evaluated using next generation sequencing (NGS). Our results showed that the MCF-7 spheroid cells were enriched with CSCs properties, indicated by the ability to self-renew, increased expression of CSCs markers, and increased resistance to chemotherapeutic drugs. Additionally, spheroid-enriched CSCs possessed greater cell proliferation, migration, invasion, and wound healing ability. A total of 134 significantly (p<0.05) differentially expressed miRNAs were identified between spheroids and parental cells using miRNA-NGS. MiRNA-NGS analysis revealed 25 up-regulated and 109 down-regulated miRNAs which includes some miRNAs previously reported in the regulation of breast CSCs. A number of miRNAs (miR-4492, miR-4532, miR-381, miR-4508, miR-4448, miR-1296, and miR-365a) which have not been previously reported in breast cancer were found to show potential association with breast cancer chemoresistance and self-renewal capability. The gene ontology (GO) analysis showed that the predicted genes were enriched in the regulation of metabolic processes, gene expression, DNA binding, and hormone receptor binding. The corresponding pathway analyses inferred from the GO results were closely related to the function of signalling pathway, self-renewability, chemoresistance, tumorigenesis, cytoskeletal proteins, and metastasis in breast cancer. Based on these results, we proposed that certain miRNAs identified in this study could be used as new potential biomarkers for breast cancer stem cell diagnosis and targeted therapy.

MicroRNA-365a-3p promotes tumor growth and metastasis in laryngeal squamous cell carcinoma

MicroRNAs (miRNAs) are increasingly recognized as oncogenes or tumor suppressors in laryngeal squamous cell carcinoma (LSCC). In this study, we analyzed the roles of miR-365a-3p, miR-143-5p, and miR-494-3p in LSCC using Annexin V/propidium iodide double staining and flow cyto-metry, along with a Transwell migration and invasion assay. The results showed that miR-365a-3p inhibitor significantly facilitated cell apoptosis and suppressed cell cycle progression, migration, and invasion in Hep-2 cells. However, miR-143-5p and miR-494-3p had no such influences. We then investigated the role of miR-365a-3p in LSCC in vivo and found that miR-365a-3p inhibitor suppressed LSCC xenograft tumor growth and metastasis in xenograft mouse models. Moreover, miR-365a-3p inhibitor significantly decreased the expression of p-AKT (Ser473), which indicated that miR-365a-3p can mediate PI3K/AKT signaling pathway transduction via p-AKT (Ser473) in LSCC. The data suggest that miR-365a-3p may act as an oncomiR and may promote growth and metastasis in LSCC via the PI3K/AKT signaling pathway, and thus miR‑365a-3p may be a potential therapeutic target for treatment of LSCC.

Circulating extracellular miR-22, miR-155, and miR-365 as candidate biomarkers to assess transport-related stress in turkeys

MicroRNA (miRNA) have been identified in circulating blood and might have the potential to be used as biomarkers for several pathophysiological conditions. To identify miRNA that are altered following stress events, turkeys (Meleagris gallopavo) were subjected to 2 h of road transportation. The expression levels of five circulating miRNA, namely miR-22, miR-155-5p, miR-181a-3p, miR-204 and miR-365-3p, were detected and assessed by quantitative polymerase chain reaction using TaqMan® probes, as potential biomarkers of stress. The areas under the receiver operating characteristic curves were then used to evaluate the diagnostic performance of miRNA. A panel of three stress-responsive miRNA, miR-22, miR-155 and miR-365 were identified; their expression levels were significantly higher after road transportation and the area under the curve (AUC) were 0.763, 0.71 and 0.704, respectively. Combining the three miRNA a specificity similar to the one found for the three miRNA separately was found. The AUC of the weighted average of the three miRNA was 0.763. This preliminary study suggests that the expression levels of circulating miR-22, miR-155 and miR-365 are increased during transport-related stress and that they may have diagnostic value to discriminate between stressed- and unstressed animals.

The role of miRNAs in cutaneous squamous cell carcinoma

MicroRNAs (miRs) are small, noncoding RNAs that negatively regulate gene expressions at posttranscriptional level. Each miR can control hundreds of gene targets and play important roles in various biological and pathological processes such as hematopoiesis, organogenesis, cell apoptosis and proliferation. Aberrant miR expression contributes to initiation and cell progression of cancers. Accumulating studies have found that miRs play a significant role in cutaneous squamous cell carcinoma (cSCC). Deregulations of miRs may contribute to cSCC carcinogenesis is through acting as oncogenic or tumour suppressive miRs. In this study, we summarized the recent data available on cSCC‐associated miRs. In particular, we will discuss the contribution of miR to the initiation and progression of cSCCs. Although there are many obstacles to be overcome, clinical use of miRs as biomarkers for diagnosis, prediction of prognosis and target for therapies, will be a promising area in the future with more expression and functional role of miRs revealed.

Serum miRNA expression in patients with esophageal squamous cell carcinoma

The aim of the present study was to investigate the feasibility and value of serum microRNAs (miRNAs/miRs) as biological markers for the prediction of the behavior and prognosis of esophageal squamous cell cancer (ESCC). The differential expression of serum miRNA was detected by an miRNA microarray of 9 patients with ESCC and 9 healthy volunteers. The result of the miRNA microarray was validated in serum samples of 69 patients with ESCC and 14 healthy volunteers by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The association between serum miRNA expression and tumor-node-metastasis (TNM) stage was analyzed. A total of 10 serum-specific miRNAs were identified from the patients with ESCC. Through PCR verification, the expression levels of miR-129, miR-451 and miR-365 were consistent with the microarray results validated by RT-qPCR, and the difference was statistically significant compared with the healthy volunteers (P=0.007, P=0.007 and P<0.001, respectively). Multivariate logistic regression analysis showed that miR-365 could serve as potential diagnostic marker for ESCC; the area under the receiver operating characteristic curve was 0.831, with a sensitivity of 80.56% and a specificity of 86.7%, but its expression did not differ significantly among the different TNM stages (stage I-II vs. III, P=0.052; stage III vs. IV, P=0.069). The expression level of miRNA-129 differed significantly among the different stages (stage I-II vs. III, P=0.002; stage III vs. IV, P=0.042), while the expression level of miR-451 did not differ significantly between stage III and IV (P=0.308). In conclusion, serum microRNAs are novel biomarkers for ESCC, and miRNA-365 and miRNA-129 can be used for the early prediction of cancer and the prediction of clinical stage, respectively.

Loss of MiR-664 Expression Enhances Cutaneous Malignant Melanoma Proliferation by Upregulating PLP2

Proteolipid protein 2 (PLP2) has been shown to be upregulated in several cancers, including breast cancer, hepatocellular carcinoma, osteosarcoma, and melanoma. PLP2 specifically binds to phosphatidylinositol 3 kinase to activate the protein kinase B pathway to enhance cell proliferation, adhesion, and invasion in melanoma cells. Therefore, we speculated that PLP2 exhibits oncogenic potential. However, the regulatory mechanisms of PLP2 in cancer cells remain unclear.Herein, we found that microRNA (miR)-664 expression was significantly downregulated in cutaneous malignant melanoma (CMM) cells and tissues compared with normal human melanocytes and benign melanocytic naevi. MiR-664 expression level was significantly correlated with patient survival. Ectopic expression of miR-664 reduced CMM cell proliferation and anchorage-independent growth, whereas the inhibition of miR-664 induced these effects. Furthermore, inhibition of miR-664 in CMM cells resulted in modulation of their entry into the G1/S transitional phase, which was caused by downregulation of the cyclin-dependent kinase inhibitor P21 and upregulation of the cell-cycle regulator cyclin D1. Moreover, we demonstrated that miR-664 downregulated PLP2 expression by directly targeting the PLP2 untranslated region.Taken together, our results suggest that miR-664 may play an important role in suppressing proliferation of CMM cells and present a novel mechanism of miR-mediated direct suppression of PLP2 expression in cancer cells.

microRNA-365-targeted nuclear factor I/B transcriptionally represses cyclin-dependent kinase 6 and 4 to inhibit the progression of cutaneous squamous cell carcinoma

Cyclin-dependent kinases are either post-transcriptionally regulated by interacting with cyclins and cyclin-dependent kinase inhibitors or are transcriptionally regulated by transcription factors, but the latter mechanism has not been extensively investigated. Dysregulated transcription factors resulting from aberrantly expressed microRNAs play critical roles in tumor development and progression. Our previous work identified miR-365 as an oncogenic microRNA that promotes the development of cutaneous squamous cell carcinoma via repression of cyclin-dependent kinase 6, while miR-365 also targets nuclear factor I/B. However, the underlying mechanism(s) of the interaction between nuclear factor I/B and cyclin-dependent kinase 6 are unclear. In this work, we demonstrate that miR-365-regulated nuclear factor I/B transcriptionally inhibits cyclin-dependent kinases 6 and 4 by binding to their promoter regions. In vivo and in vitro experiments demonstrate that the loss of nuclear factor I/B after miR-365 expression or treatment with small interfering RNAs results in the upregulation of cyclin-dependent kinases 6 and 4. This upregulation, in turn, enhances the phosphorylation of retinoblastoma protein and tumor progression. Characterizing this transcriptional repression of cyclin-dependent kinases 6 and 4 by nuclear factor I/B contributes to the understanding of the transcriptional regulation of cyclin-dependent kinases by transcription factors and also facilitates the development of new therapeutic regimens to improve the clinical treatment of cutaneous squamous cell carcinoma.