miR-21-3p is a positive regulator of L1CAM in several human carcinomas

Advances in MiRNAs Involved in Endometrial Carcinoma

Endometrial carcinoma (EC) is a common malignancy worldwide. Existing evidence has revealed that EC could be associated with abnormal gene expression. Meantime, evidence supports that miRNAs act as critical regulators in gene expression through the binding to the 3'- untranslated region (3'-UTR). Accordingly, this review concludes some recent studies focusing on miRNAs that influence EC, aiming at understanding the association between miRNAs and EC more clearly and providing a reference for further studies on miRNA-related drugs treating EC.

The correlation between cancer stem cells and epithelial-mesenchymal transition: molecular mechanisms and significance in cancer theragnosis

The connections between cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT) is critical in cancer initiation, progression, metastasis, and therapy resistance, making it a focal point in cancer theragnosis. This review provides a panorama of associations and regulation pathways between CSCs and EMT, highlighting their significance in cancer. The molecular mechanisms underlined EMT are thoroughly explored, including the involvement of key transcription factors and signaling pathways. In addition, the roles of CSCs and EMT in tumor biology and therapy resistance, is further examined in this review. The clinical implications of CSCs-EMT interplay are explored, including identifying mesenchymal-state CSC subpopulations using advanced research methods and developing targeted therapies such as inhibitors and combination treatments. Overall, understanding the reciprocal relationship between EMT and CSCs holds excellent potential for informing the development of personalized therapies and ultimately improving patient outcomes.

Crosstalk between breast cancer-derived microRNAs and brain microenvironmental cells in breast cancer brain metastasis

Breast cancer is the most frequent malignancy in women, constituting 15.2% of all new cancers diagnosed in the United States. Distant breast cancer metastasis accounts for the majority of breast cancer-related deaths; brain metastasis is the third most common site for metastatic breast cancer but is associated with worst prognosis of approximately eight months of survival. Current treatment options for breast cancer brain metastasis (BCBM) are limited and ineffective. To help identify new and effective therapies for BCBM, it is important to investigate the mechanisms by which breast cancer cells metastasize to the brain and thrive in the brain microenvironment. To this end, studies have reported that primary breast tumor cells can prime brain microenvironmental cells, including, astrocytes and microglia, to promote the formation of BCBM through the release of extracellular vesicle-microRNAs (miRNAs). Breast tumor-derived miRNAs can also promote breast cancer cell invasion through the blood-brain barrier by disrupting the integrity of the brain microvascular endothelial cells. In this review, we summarize current literature on breast cancer-derived BCBM-promoting miRNAs, cover their roles in the complex steps of BCBM particularly their interactions with microenvironmental cells within the brain metastatic niche, and finally discuss their therapeutic applications in the management of BCBM.

L1CAM is required for early dissemination of fallopian tube carcinoma precursors to the ovary

Most ovarian high-grade serous carcinomas (HGSC) arise from Serous Tubal Intraepithelial Carcinoma (STIC) lesions in the distal end of the fallopian tube (FT). Formation of STIC lesions from FT secretory cells leads to seeding of the ovarian surface, with rapid tumor dissemination to other abdominal structures thereafter. It remains unclear how nascent malignant cells leave the FT to colonize the ovary. This report provides evidence that the L1 cell adhesion molecule (L1CAM) contributes to the ability of transformed FT secretory cells (FTSEC) to detach from the tube, survive under anchorage-independent conditions, and seed the ovarian surface. L1CAM was highly expressed on the apical cells of STIC lesions and contributed to ovarian colonization by upregulating integrins and fibronectin in malignant cells and activating the AKT and ERK pathways. These changes increased cell survival under ultra-low attachment conditions that mimic transit from the FT to the ovary. To study dissemination to the ovary, we developed a tumor-ovary co-culture model. We showed that L1CAM expression was important for FT cells to invade the ovary as a cohesive group. Our results indicate that in the early stages of HGSC development, transformed FTSECs disseminate from the FT to the ovary in a L1CAM-dependent manner.

Intraabdominal sporadic desmoid tumors and inflammation: an updated literature review and presentation and insights on pathogenesis of synchronous sporadic mesenteric desmoid tumors occurring after surgery for necrotizing pancreatitis

Sporadic intra-abdominal desmoid tumors are rare and known to potentially occur after trauma including previous surgery, although knowledge of the underlying pathogenetic mechanism is still limited. We reviewed the recent literature on sporadic intraabdominal desmoids and inflammation as we investigated the mutational and epigenetic makeup of a case of multiple synchronous mesenterial desmoids occurring after necrotizing pancreatitis. A 62-year-old man had four mesenteric masses up to 4.8 cm diameter detected on CT eighteen months after laparotomy for peripancreatic collections from necrotizing pancreatitis. All tumors were excised and diagnosed as mesenteric desmoids. DNA from peripheral blood was tested for a multigene panel. The tumour DNA was screened for three most frequent β-catenin gene mutations T41A, S45F and S45P. Expression levels of miR-21-3p and miR-197-3-p were compared between the desmoid tumors and other wild-type sporadic desmoids. The T41A CTNNB1 mutation was present in all four desmoid tumors. miR-21-3p and miR-197-3p were respectively upregulated and down-regulated in the mutated sporadic mesenteric desmoids, with respect to wild-type lesions. The patient is free from recurrence 34 months post-surgery. The literature review did not show similar studies. To our knowledge, this is the first study to interrogate genetic and epigenetic signature of multiple intraabdominal desmoids to investigate potential association with abdominal inflammation following surgery for necrotizing pancreatitis. We found mutational and epigenetic features that hint at potential activation of inflammation pathways within the desmoid tumor.

Exosomes on Endometrial Cancer: A Biomarkers Treasure Trove?

Endometrial cancer (EC) is one of the main causes of cancer-related death among women. In the last decade, the incidence of EC is on the rise, and the relative 5-year survival remains unchanged. This creates a dire need for new diagnostic and therapeutic approaches that can only result from a deeper understanding of the pathogenesis of the disease. In this direction, exosomes are under heavy research, with two main aims: to identify the potential diagnostic and prognostic markers and to develop technologies based on their use as therapeutic vectors targeting EC cells. Exosomes are widely available in all bodily fluids and are sources of ideal biomarkers for liquid biopsies. They are extracellular vesicles containing DNA, RNA, lipids, and proteins, which they transfer between cells, serving multiple functions and being implicated in both the physiological processes and the pathogenesis of diseases. Of all the biomolecules contained in exosomes, microRNAs (miRNAs) seem to have the most clinical utility in the diagnosis and treatment of EC. Exosomal miRNAs mediate the communication between EC cells, cancer-associated fibroblasts (CAFs), and tumor-associated macrophages (TAMs) and have a pivotal role in the tumor cells' proliferation, epithelial to mesenchymal transition (EMT), and the formation of a tumor microenvironment. They participate in many processes that are tied to carcinogenesis and cancer progression, and they are therefore considered as attractive therapeutic targets. Here, we review the functions of exosomes in EC, focusing on potential biomarkers of diagnostic and prognostic significance or potential therapeutic use.

Hsa-miR-21-3p associates with breast cancer patient survival and targets genes in tumor suppressive pathways

Breast cancer is the cancer most often diagnosed in women. MicroRNAs (MIRs) are short RNA molecules that bind mRNA resulting in their downregulation. MIR21 has been shown to be an oncomiR in most cancer types, including breast cancer. Most of the effects of miR-21 have been attributed to hsa-miR-21-5p that is transcribed from the leading strand of MIR21, but hsa-miR-21-3p (miR-21-3p), transcribed from the lagging strand, is much less studied. The aim of the study is to analyze whether expression of miR-21-3p is prognostic for breast cancer. MiR-21-3p association with survival, clinical and pathological characteristics was analyzed in a large breast cancer cohort and validated in three separate cohorts, including TCGA and METABRIC. Analytical tools were also used to infer miR-21-3p function and to identify potential target genes and functional pathways. The results showed that in the exploration cohort, high miR-21-3p levels associated with shorter survival and lymph node positivity. In the three validation cohorts, high miR-21-3p levels associated with pathological characteristics that predict worse prognosis. Specifically, in the largest validation cohort, METABRIC (n = 1174), high miR-21-3p levels associated with large tumors, a high grade, lymph node and HER2 positivity, and shorter breast-cancer-specific survival (HR = 1.38, CI 1.13–1.68). This association remained significant after adjusting for confounding factors. The genes with expression levels that correlated with miR-21-3p were enriched in particular pathways, including the epithelial-to-mesenchymal transition and proliferation. Among the most significantly downregulated targets were MAT2A and the tumor suppressive genes STARD13 and ZNF132. The results from this study emphasize that both 3p- and 5p-arms from a MIR warrant independent study. The data show that miR-21-3p overexpression in breast tumors is a marker of worse breast cancer progression and it affects genes in pathways that drive breast cancer by down-regulating tumor suppressor genes. The results suggest miR-21-3p as a potential biomarker.

Diagnostic and Prognostic Value of MicroRNAs in Metastasis and Recurrence of Head and Neck Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

MicroRNAs have been proven to make remarkable differences in the clinical behaviors of head and neck squamous cell carcinoma (HNSCC). This study aims to systematically analyze whether differential expression levels of microRNAs are related to recurrence or metastasis in patients with HNSCC. A comprehensive search of the PubMed, EMBASE, and CENTRAL was conducted up to July 24^th, 2021. Data were collected and combined from studies reporting recurrence-free survival (RFS) of HNSCC patients with high microRNA expression compared to those with low expression. Besides, studies providing necessary data for evaluating the diagnostic value of microRNAs for detecting recurrence and metastasis based on their expression levels were also included and combined. The pooled hazard ratio (HR) value for the outcomes of RFS in 1,093 HNSCC samples from 10 studies was 2.51 (95%CI: 2.13–2.96). A sensitivity of 0.79 (95% CI: 0.72–0.85) and specificity of 0.77 (95%CI: 0.68–0.83) were observed in three studies, of which 93 patients with recurrence and 82 nonrecurrence controls were included, and the area under the curve (AUC) was 0.85 (95% CI: 0.81–0.88). Additionally, high diagnostic accuracy of microRNAs in detecting lymph node metastasis (LNM) was also reported. In conclusion, two panels of microRNAs showed the potential to predict recurrence or diagnose recurrence in HNSCC patients, respectively, which could facilitate prognosis prediction and diagnosis of clinical behaviors in HNSCC patients.

MicroRNA-21: An Emerging Player in Bone Diseases

MicroRNAs (MiRNAs) are small endogenous non-coding RNAs that bind to the 3′-untranslated region of target genes and promote their degradation or inhibit translation, thereby regulating gene expression. MiRNAs are ubiquitous in biology and are involved in many biological processes, playing an important role in a variety of physiological and pathological processes. MiRNA-21 (miR-21) is one of them. In recent years, miR-21 has received a lot of attention from researchers as an emerging player in orthopedic diseases. MiR-21 is closely associated with the occurrence, development, treatment, and prevention of orthopedic diseases through a variety of mechanisms. This review summarizes its effects on osteoblasts, osteoclasts and their relationship with osteoporosis, fracture, osteoarthritis (OA), osteonecrosis, providing a new way of thinking for the diagnosis, treatment and prevention of these bone diseases.

Role of L1CAM in retinoblastoma tumorigenesis: identification of novel therapeutic targets

The study presented focuses on the role of the neuronal cell adhesion molecule L1 cell adhesion molecule (L1CAM) in retinoblastoma (RB), the most common malignant intraocular childhood tumor. L1CAM is differentially expressed in a variety of human cancers and has been suggested as a promising therapeutic target. We likewise observed differential expression patterns for L1CAM in RB cell lines and patient samples. The two proteases involved in ectodomain shedding of L1CAM (L1CAM sheddases: ADAM10 and ADAM17) were likewise differentially expressed in the RB cell lines investigated, and an involvement in L1CAM processing in RB cells could be verified. We also identified ezrin, galectin-3, and fibroblast growth factor basic as L1CAM signaling target genes in RB cells. Lentiviral L1CAM knockdown induced apoptosis and reduced cell viability, proliferation, growth, and colony formation capacity of RB cells, whereas L1CAM-overexpressing RB cells displayed the opposite effects. Chicken chorioallantoic membrane assays revealed that L1CAM depletion decreases the tumorigenic and migration potential of RB cells in vivo. Moreover, L1CAM depletion decreased viability and tumor growth of etoposide-resistant RB cell lines upon etoposide treatment in vitro and in vivo. Thus, L1CAM and its processing sheddases are potential novel targets for future therapeutic RB approaches.

LINC00461 Promoted Endometrial Carcinoma Growth and Migration by Targeting MicroRNA-219-5p/Cyclooxygenase-2 Signaling Axis

Endometrial carcinoma (EC) ranks as the most common female genital cancer in developed countries. Lately, more and more long noncoding RNAs (lncRNAs) have been identified as vital regulators in numerous physiological and pathological processes, including EC. However, the expression pattern and precise functions of different lncRNAs in EC remain unclear. In this study, we reported LINC00461 was upregulated in EC patient tissues and cell lines. In addition, LINC00461 knockdown could remarkably suppress cell proliferation, cell cycle progression, cell migration, and promote cell apoptosis in EC cells. We discovered LINC00461 could sponge microRNA-219-5p (miR-219-5p) and suppress its expression, thereby upregulating expression level of miR-219-5p's target, cyclooxygenase-2 (COX-2). In vivo animal models, LINC00461 knockdown inhibited tumor growth by increasing miR-219-5p level and reducing COX-2 expression, thus confirming LINC00461 functions as an oncogene in EC. In this study, a novel regulatory role of LINC00461/miR-219-5p/COX-2 axis was systematically investigated in context of EC, with the aim to provide promising intervention targets for EC therapy from bench to clinic. [Formula: see text].

Breast cancer organoid model allowed to reveal potentially beneficial combinations of 3,3'-diindolylmethane and chemotherapy drugs

Epigenetic alterations represent promising therapeutic targets in cancer treatment. Recently it was revealed that small molecules have the potential to act as microRNA silencers. Capacity to bind the discrete stem-looped structure of pre-miR-21 and prevent its maturation opens opportunities to utilize such compounds for the prevention of initiation, progression, and chemoresistance of cancer. Molecular simulations performed earlier identified 3,3'-diindolylmethane (DIM) as a potent microRNA-21 antagonist. However, data on DIM and microRNA-21 interplay is controversial, which may be caused by the limitations of the cell lines.

Endometrial Cancer Cells Promote M2-Like Macrophage Polarization by Delivering Exosomal miRNA-21 under Hypoxia Condition

Increasing evidence has demonstrated that hypoxia was an aggressive feature in endometrial cancer (EC), which is significantly associated with the tumor grade, lymph node metastasis, and tumor resistance to chemotherapy. However, the relationship between hypoxia and the immune microenvironment in EC is not very clear. Exosomes are small membrane vesicles secreted from a variety of cell types which mediate cell-to-cell communication through transported biomolecules. Here, we investigated whether exosomes can play an immunomodulatory role in intercellular communication between EC cells and macrophages. EC KEL cells were cultured under hypoxia or normoxic condition to collect exosomes. After identification, the exosomes derived from hypoxic or normoxic KEL cells were cultured with the monocyte cell line THP-1 to study the immunoregulation function of KEL cells. The results showed that the total number of exosomes produced by hypoxic KEL cells was significantly higher than that in normoxic condition. In addition, hypoxia markedly stimulated the increase in miRNA-21 expression in the exosomes. After coculture, we found that exosomal miRNA-21 could be horizontally transferred into THP-1 cells. And then, the notably enhanced mRNA expression levels of IL-10 and CD206 in THP-1 cells were observed, suggestive of M2 polarization. To further study the effect of miRNA-21-containing exosomes, we transfected miRNA-21 mimics or inhibitor into THP-1 cells. The results showed that miRNA-21 mimics promoted IL-10 and CD206 mRNA expression levels, and the miRNA-21 inhibitor significantly prevented the alteration induced by intake of hypoxic KEL cell-derived exosomes. In summary, we found that endometrial cancer KEL cells in hypoxic condition promoted monocyte THP-1 cell transformation to M2-like polarization macrophages through delivering exosomal miRNA-21, which may be a potential mechanism of the formation of the immune microenvironment in EC progression.

microRNAs Orchestrate Pathophysiology of Breast Cancer Brain Metastasis: Advances in Therapy

Brain metastasis (BM) predominantly occurs in triple-negative (TN) and epidermal growth factor 2 (HER2)-positive breast cancer (BC) patients, and currently, there is an unmet need for the treatment of these patients. BM is a complex process that is regulated by the formation of a metastatic niche. A better understanding of the brain metastatic processes and the crosstalk between cancer cells and brain microenvironment is essential for designing a novel therapeutic approach. In this context, the aberrant expression of miRNA has been shown to be associated with BM. These non-coding RNAs/miRNAs regulate metastasis through modulating the formation of a metastatic niche and metabolic reprogramming via regulation of their target genes. However, the role of miRNA in breast cancer brain metastasis (BCBM) is poorly explored. Thus, identification and understanding of miRNAs in the pathobiology of BCBM may identify a novel candidate miRNA for the early diagnosis and prevention of this devastating process. In this review, we focus on understanding the role of candidate miRNAs in the regulation of BC brain metastatic processes as well as designing novel miRNA-based therapeutic strategies for BCBM.

Effect of miR-21 on apoptosis in hepatoblastoma cell through activating ASPP2/p38 signaling pathway in vitro and in vivo

The objective of this study was to investigate the mechanism underlying miR-21-associated apoptosis in HB. In this study, HB and adjacent tissues were collected from patients with HB. RT-PCR, FISH, western blot, apoptosis assay, migration, invasion and wound healing assays, caspase activity assay, luciferase reporter assays, and xenografts mouse model were used to determine the effects of miR-21 on HB cell apoptosis. The results revealed that miR-21 was up-regulated in both HB cell and tissue and was associated with progression of HB. MiR-21 inhibitor enhanced the apoptosis level in HB cells. MiR-21 inhibitor showed reduced abilities of migration and invasion. ASPP2 was a target gene of miR-21. Inhibition of ASPP2 increased abilities of migration and invasion in HB cells. Furthermore, miR-21 inhibitor caused increased activity p-38 signaling. In a xenografts mouse model, miR-21 inhibitor could significantly suppress tumor growth in nude mice along with enhanced expressions of ASPP2 and p38. Taken together, the results suggest that upregulation of miR-21 is related to HB progression and miR-21-associated apoptosis in HB is mediated through ASPP2/p38 signaling pathway in vitro and in vivo. This study provides novel insight into the effects of miR-21 on HB apoptosis and clue to develop new therapies.

L1CAM Predicts Adverse Outcomes in Patients with Endometrial Cancer Undergoing Full Lymphadenectomy and Adjuvant Chemotherapy

BACKGROUND

L1 cell adhesion molecule (L1CAM) has been established as an important predictor of poor survival of early-stage endometrial cancer patients. We investigated whether L1CAM remains a significant predictor of poor survival of patients with advanced-stage endometrial cancer undergoing extensive surgical staging and adjuvant chemotherapy.

METHODS

We prepared tissue microarray (TMA) from surgical tissue specimens of 161 endometrial cancer patients who underwent full lymphadenectomy combined with adjuvant chemotherapy for patients at risk for recurrence, and evaluated expression of L1CAM using immunohistochemistry. The correlation between L1CAM positivity and clinicopathological factors and the prognostic significance of L1CAM expression was investigated.

RESULTS

Among 161 cases who had a follow-up duration of over 3 years, 48 cases (29.8%) showed positive staining for L1CAM. L1CAM positivity was significantly correlated with non-endometrioid histology (p < 0.0001), vascular invasion (p = 0.0157), and positive cytology (p = 0.005), and was a significant predictor of poor survival among advanced-stage patients, but not early-stage patients in our cohort. L1CAM-positive patients showed a higher recurrence rate and frequency of distant failure than L1CAM-negative patients. Multivariate analysis revealed that para-aortic lymph node metastasis (PANM) and L1CAM positivity were independent predictors of poor survival. Overall survival can be stratified into three groups by the combination of PANM and L1CAM positivity.

CONCLUSION

L1CAM is an independent predictor of poor survival in endometrial cancer patients undergoing full lymphadenectomy and adjuvant chemotherapy, thus indicating that L1CAM can be clinically used as a biomarker to identify those patients at increased risk of recurrence.

Three-microRNA expression signature predicts survival in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a specific type of breast cancer with poor overall survival (OS) time. Previous studies revealed that microRNAs (miRNAs/miRs) serve important roles in the pathogenesis, progression and prognosis of TNBC. The present study analyzed the miRNA expression and clinical data of patients with TNBC downloaded from The Cancer Genome Atlas. A total of 194 differentially expressed miRNAs were identified between TNBC and matched normal tissues using the cut-off criteria of P<0.05 and |log2 fold change|>2. Of these miRNAs, 65 were downregulated and 129 were upregulated. Using Kaplan-Meier survival analysis, a total of 77 miRNAs that were closely associated with OS time were identified (P<0.05). The intersection of the 77 miRNAs and 194 differentially expressed miRNAs revealed six miRNAs. Log-rank tests based on survival curves were performed and two miRNAs were eliminated. The prognostic value of the remaining four miRNAs was evaluated with a Cox proportional hazards model using multiple logistic regression with forward stepwise selection of variables. Three miRNAs (miR-21-3p, miR-659-5p and miR-200b-5p) were subsequently identified as independent risk factors associated with OS time in the model. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses revealed that the target genes of these three miRNAs were mainly involved in ‘cell protein metabolism’, ‘RNA transcriptional regulation’, ‘cell migration’, ‘MAPK signaling pathway’, ‘ErbB signaling pathway’, ‘prolactin signaling pathway’ and ‘adherens junctions’. Taken together, the results obtained in the present study suggested that the three-miRNA signature may serve as a prognostic biomarker for patients with TNBC.

Identification of lncRNA NEAT1/miR-21/RRM2 axis as a novel biomarker in breast cancer

As a major disease that threatens the health of women worldwide, breast cancer (BC) lacks effective molecular markers in the clinic at the same time. We aim at finding a new biomarker of BC. In our study, through the Gene Expression Omnibus database chip, a total of 1393 pairs of microRNA-messenger RNA (miRNA-mRNA) networks and 35754 pairs of long noncoding RNA-miRNA networks were obtained. We found out that NEAT1/miR-21/RRM2 axis may play a role in BC diagnosis and prognosis. The real-time quantitative reverse transcription-polymerase chain reaction test was used to analyze the mRNA level of NEAT1, miR-21, and RRM2. Western blot was used to detect the protein level of RRM2. Through the 5-ethynyl-2'-deoxyuridine assay, the proliferation of MDA-MB-231 cells was detected. Through wound healing and transwell assay, the migration of MDA-MB-231 cells was detected. Altogether, our data indicated that NEAT1, miR-21, and RRM2 were upregulated in several BC cell lines. Overexpressed of miR-21 in MDA-MB-231 cells promote proliferation and migration. Besides, our results demonstrated that overexpressed of miR-21 upregulated the level of RRM2. Accordingly, miR-21/RRM2 might be a new diagnosis and treatment target of BC.

Exosomes from nicotine-stimulated macrophages accelerate atherosclerosis through miR-21-3p/PTEN-mediated VSMC migration and proliferation

Rationale: During the development of atherosclerosis, macrophages secrete exosomes that regulate vascular smooth muscle cells (VSMCs); however, whether nicotine, a major constituent of cigarettes, can modulate this communication in the context of atherogenesis remains to be further studied. In this study, we hypothesized that nicotine induces macrophages to secrete atherogenic exosomes containing microRNAs (miRNAs) to mediate cell-to-cell crosstalk and encourage proatherogenic phenotypes of VSMCs.

Methods: In an in vivo study, nicotine was administered subcutaneously to 8-week-old male ApoE^-/- mice fed a high-fat diet (HFD) for 12 weeks. Oil red O and hematoxylin and eosin (HE) were used to stain atherosclerotic lesions. Lesion macrophages, VSMCs and exosomes were stained for CD68, α-smooth muscle actin (α-SMA) and CD9, and plaque exosomes were observed by transmission electron microscopy (TEM). Exosomes derived from control macrophages (M-Exos) and from nicotine-treated macrophages (NM-Exos) were isolated by ultracentrifugation, purified by sucrose density gradient centrifugation and characterized based on specific morphology and surface markers. The IVIS® Spectrum in vivo imaging system showed the biodistribution of NM-Exos and M-Exos in circulation. Chitosan hydrogel-incorporated exosomes were applied to simulate exosome secretion in situ. Scratch wound assay, transwell assay and EdU staining were conducted to assess the effects of NM-Exos on the migration and proliferation of mouse VSMCs. RNA-seq was performed to determine the miRNA profiles of M-Exos and NM-Exos. Quantitative real-time PCR (qRT-PCR) analysis was conducted to detect the expression levels of miRNAs and mRNAs. The roles of the candidate miRNA and its target gene were assessed using specific RNA inhibitors, siRNAs and miRNA mimics. Western blotting was used to detect candidate protein expression levels. A dual-luciferase reporting system was utilized to confirm the binding of a specific miRNA to its target gene.

Results: Nicotine induced atherosclerotic lesion progression and resulted in plaque exosome retention in vivo. The biodistribution of NM-Exos showed that plaque-resident exosomes might be secreted in situ. VSMCs cocultured in vitro with nicotine-stimulated macrophages presented an increased capacity for migration and proliferation, which was exosome-dependent. In addition, isolated NM-Exos helped promote VSMC migration and proliferation. miRNA profiling showed that miR-21-3p was enriched in NM-Exos, and this miRNA was shown to play a key role in regulating NM-Exos-induced effects by directly targeting phosphatase and tension homologue (PTEN).

Conclusion: Exosomal miR-21-3p from nicotine-treated macrophages may accelerate the development of atherosclerosis by increasing VSMC migration and proliferation through its target PTEN.

Identification and Validation of Circulating MicroRNA Signatures for Breast Cancer Early Detection Based on Large Scale Tissue-Derived Data

Purpose

Breast cancer is the most commonly occurring cancer among women worldwide, and therefore, improved approaches for its early detection are urgently needed. As microRNAs (miRNAs) are increasingly recognized as critical regulators in tumorigenesis and possess excellent stability in plasma, this study focused on using miRNAs to develop a method for identifying noninvasive biomarkers.

Methods

To discover critical candidates, differential expression analysis was performed on tissue-originated miRNA profiles of 409 early breast cancer patients and 87 healthy controls from The Cancer Genome Atlas database. We selected candidates from the differentially expressed miRNAs and then evaluated every possible molecular signature formed by the candidates. The best signature was validated in independent serum samples from 113 early breast cancer patients and 47 healthy controls using reverse transcription quantitative real-time polymerase chain reaction.

Results

The miRNA candidates in our method were revealed to be associated with breast cancer according to previous studies and showed potential as useful biomarkers. When validated in independent serum samples, the area under curve of the final miRNA signature (miR-21-3p, miR-21-5p, and miR-99a-5p) was 0.895. Diagnostic sensitivity and specificity were 97.9% and 73.5%, respectively.

Conclusion

The present study established a novel and effective method to identify biomarkers for early breast cancer. And the method, is also suitable for other cancer types. Furthermore, a combination of three miRNAs was identified as a prospective biomarker for breast cancer early detection.

Gender-dependent expression of leading and passenger strand of miR-21 and miR-16 in human colorectal cancer and adjacent colonic tissues

miRNAs are small regulatory RNA molecules involved in posttranscriptional gene silencing. Their biosynthesis results in the formation of duplex consisting of a leading and a passenger strand of mature miRNA. The leading strand exhibits the main activity but recent findings indicate a certain role of the passenger strand as well. Deregulated levels of miRNA were found in many types of cancers including colorectal cancer. miR-21 and miR-16 were indicated as possible markers of colorectal cancer, however, small attention to gender differences in their expression was paid so far. Therefore, the aim of our study was to investigate the expression of miR-21-5p, miR-21-3p, miR-16-5p and miR-16-3p in human colorectal cancer tissue and compare it to the adjacent tissues taken during surgery in men and women separately. Our results showed an up-regulation of all measured miRNAs in tumor tissue compared to adjacent tissues. As expected, tumors and adjacent tissues exhibited a significantly higher expression of leading miRNAs compared to passenger strand of miR-21 and miR-16. The expression of leading and passenger strand of miR-21 and miR-16 positively correlated exhibiting the highest correlation coefficient in the distal tissue. The expression pattern showed gender-dependent differences, with higher levels of miRNA in men than in women. Our findings indicate a gender-related expression pattern of miRNA, which should be considered as an important factor in generating new prognostic or diagnostic biomarkers.

Human microRNA expression in sporadic and FAP-associated desmoid tumors and correlation with beta-catenin mutations

Desmoid tumors (DT) are rare, benign, fibroblastic neoplasm with challenging histological diagnosis. DTs can occur sporadically or associated with the familial adenomatous polyposis coli (FAP). Most sporadic DTs are associated with β-catenin gene (CTNNB1) mutations, while mutated APC gene causes FAP disease. microRNAs (miRNAs) are involved in many human carcinogenesis.

The miRNA profile was analyzed by microarray in formalin-fixed, paraffin-embedded (FFPE) specimens of 12 patients (8 sporadic, 4 FAP-associated) and 4 healthy controls. One hundred and one mRNAs resulted dysregulated, of which 98 in sporadic DTs and 8 in FAP-associated DTs, 5 were shared by both tumors. Twenty-six miRNAs were then validated by RT-qPCR in 23 sporadic and 7 FAP-associated DT samples matched with healthy controls. The qPCR method was also used to evaluate the CTNNB1 mutational status in sporadic DTs. The correlation between sporadic DTs and miRNA expression showed that miR-21-3p increased in mutated versus wild-type DTs, while miR-197-3p was decreased. The mRNA expression of Tetraspanin3 and Serpin family A member 3, as miR-21-3p targets, and L1 Cell Adhesion Molecule, as miR-197-3p target, was also evaluate. CTNNB1 mutations associated to miRNA dysregulation could affect the genesis and the progression of this disease and help histological diagnosis of sporadic DTs.

Evaluating L1CAM expression in human endometrial cancer using qRT-PCR

Background

Management of endometrial carcinoma (EC) still needs improvement of risk assessment. Recently, L1CAM immunohistochemical (IHC) evaluation showed a unique value to predict the outcome of early EC. However IHC results are often conflicting for lack of inter-laboratory standardisation.

Methods

Here, as a proof of concept and to increase reproducibility we assayed eighty-two EC and 26 normal endometrium samples for L1CAM expression (L1CAM^EXP) via qRT-PCR. The IHC evaluation was performed in 50 cancer samples. Moreover, we aimed to substantiate the in-vitro findings of L1CAM regulation through its promoter methylation (L1CAM^MET), miR-34a expression and miR-34a promoter methylation. DNA methylation was assessed with MethyLight PCR technique.

Results

High overall concordant results between IHC and RT-PCR evaluations were found. L1CAM^EXP was detected in 11% of cancer specimens. These positive cancers exhibited a worse DFS (p=0.032) and OS (p=0.016) in a multivariate COX-regression model. L1CAM^EXP predicted distant failure (p=0.007) and L1CAM^MET predicted risk-reduction of lymph-node involvement (p=0.005). Inverse correlations between L1CAM^EXP and L1CAM^MET (p=0.004) and between L1CAM^EXP and miR-34a expression (p=0.002) were found.

Conclusions

In conclusion qRT-PCR analysis is a reliable approach to evaluate L1CAM status in EC and L1CAM^EXP was highly predictive for distant failure and poor outcome, confirming the large IHC-based studies. Interestingly, L1CAM^MET was able to assess the risk of pelvic lymph-node involvement. Especially the latter finding has to be confirmed in larger prospective series.

Different miR-21-3p isoforms and their different features in colorectal cancer

MiR-21, the only microRNA (miRNA) found to be overexpressed in any type of solid tumor, its guide stand, miR-21-5p, has been studied a lot in colorectal cancer (CRC); however, few researchers focused on its passenger strand, miR-21-3p. In our study, based on The Cancer Genome Atlas (TCGA) data, we found that there were more varieties and quantities of miR-21-3p isoforms in microsatellite instability (MSI)-type CRC. We further examined the role of miR-21-3p by in vitro and in vivo studies. MiR-21-3p may be an oncogene in CRC by promoting cellular mobility through epithelial-mesenchymal transition. However, different isoforms, especially miR-21-3p 0 | 2, may be a favorable prognostic marker for CRC survival, probably due to increased complementary effect of miR-21-5p and/or target genes. Further study investigating the underlying mechanism of miRNA isoforms is needed.

MicroRNAs driving invasion and metastasis in ovarian cancer: Opportunities for translational medicine (Review)

Epithelial ovarian cancer is the fifth most frequent cause of cancer death in women. In spite of the advantages in early detection and treatment options, overall survival rates have improved only slightly in the last decades. Therefore, alternative therapeutic approaches need to overcome resistance and improve the patient survival and outcome. MicroRNAs are evolutionary conserved small non-coding RNAs that function as negative regulators of gene expression by inhibiting translation or inducing degradation of messenger RNAs. In cancer, microRNAs are aberrantly expressed thus representing potential prognostic biomarkers and novel therapeutic targets. The knowledge of novel and unexpected functions of microRNAs is rapidly evolving and the advance in the elucidation of potential clinical applications deserves attention. Recently, a specific set of microRNAs dubbed as metastamiRs have been shown to initiate invasion and metastasis in diverse types of cancer. We reviewed the current status of microRNAs in development and progression of ovarian cancer with a special emphasis on tumor cells invasion and metastasis. Also, we show an update of microRNA functions in oncogenic pathways and discuss the current scenario for potential applications in clinical and translational research in ovarian cancer.

Integrated host and viral transcriptome analyses reveal pathology and inflammatory response mechanisms to ALV-J injection in SPF chickens

Avian leukosis virus (ALV) is detrimental to poultry health and causes substantial economic losses from mortality and decreased performance. Because tumorigenesis is a complex mechanism, the regulatory architecture of the immune system is likely to include the added dimensions of modulation by miRNAs and long-noncoding RNA (lncRNA). To characterize the response to ALV challenge, we developed a novel methodology that combines four datasets: mRNA expression and the associated regulatory factors of miRNA and lncRNA, and ALV gene expression. Specific Pathogen-Free (SPF) layer chickens were infected with ALV-J or maintained as non-injected controls. Spleen samples were collected at 40 days post injection (dpi), and sequenced. There were 864 genes, 7 miRNAs and 17 lncRNAs differentially expressed between infected and non-infected birds. The combined analysis of the 4 RNA expression datasets revealed that ALV infection is detected by pattern-recognition receptors (TLR9 and TLR3) leading to a type-I IFN mediated innate immune response that is modulated by IRF7 and IRF1. Co-expression network analysis of mRNA with miRNA, lncRNA and virus genes identified key elements within the complex networks utilized during ALV response. The integration of information from the host transcriptomic, epigenetic and virus response also has the potential to provide deeper insights into other host-pathogen interactions.

Visual Display of 5p-arm and 3p-arm miRNA Expression with a Mobile Application

MicroRNAs (miRNAs) play important roles in human cancers. In previous studies, we have demonstrated that both 5p-arm and 3p-arm of mature miRNAs could be expressed from the same precursor and we further interrogated the 5p-arm and 3p-arm miRNA expression with a comprehensive arm feature annotation list. To assist biologists to visualize the differential 5p-arm and 3p-arm miRNA expression patterns, we utilized a user-friendly mobile App to display. The Cancer Genome Atlas (TCGA) miRNA-Seq expression information. We have collected over 4,500 miRNA-Seq datasets from 15 TCGA cancer types and further processed them with the 5p-arm and 3p-arm annotation analysis pipeline. In order to be displayed with the RNA-Seq Viewer App, annotated 5p-arm and 3p-arm miRNA expression information and miRNA gene loci information were converted into SQLite tables. In this distinct application, for any given miRNA gene, 5p-arm miRNA is illustrated on the top of chromosome ideogram and 3p-arm miRNA is illustrated on the bottom of chromosome ideogram. Users can then easily interrogate the differentially 5p-arm/3p-arm expressed miRNAs with their mobile devices. This study demonstrates the feasibility and utility of RNA-Seq Viewer App in addition to mRNA-Seq data visualization.

Plasma-specific microRNA response induced by acute exposure to aristolochic acid I in rats

Aristolochic acid I (AAI) derived from a natural herbal alkaloid is a nephrotoxicant. AAI-induced acute kidney injury (AKI), a devastating clinical disease associated with high mortality rates, is difficult for early diagnosis. To address this issue, we identified and validated early-detection biomarkers for AAI-induced acute kidney injury via profiling microRNA expression in rats. Global miRNA expression profile analysis found that 21 miRNAs were significantly dysregulated in kidney of rats treated by 40 mg/kg AAI on day 2, day 4, or day 6, among which 5 miRNAs were upregulated at all three time points. Quantitative RT-PCR confirmed that miR-21-3p on day 4 and day 6 was obviously upregulated in kidney of rats treated by 40 mg/kg AAI. Further examination found that miR-21-3p was increased in plasma early on day 2 in 10 mg/kg AAI-treated rats, but not in non-target organs. Importantly, the elevation of plasma miR-21-3p preceded the increase in blood urea nitrogen and creatinine, and the presence of renal tubular injury, characterized by differential increase before and after the presence of renal tubular lesions. Our findings thus show that miRNA expression is upregulated in kidney and plasma of AKI rat induced by AAI, and plasma miR-21-3p may be served as a new potential biomarker for early diagnosing AAI-induced acute kidney injury in rats, and possibly in humans.

miRNA dynamics in tumor-infiltrating myeloid cells modulating tumor progression in pancreatic cancer

Myeloid cells including tumor-associated macrophages (TAM) and myeloid-derived suppressor cells (MDSC) are known as important mediators of tumor progression in solid tumors such as pancreatic cancer. Infiltrating myeloid cells have been identified not only in invasive tumors, but also in early pre-invasive pancreatic intraepithelial precursor lesions (PanIN). The functional dynamics of myeloid cells during carcinogenesis is largely unknown. We aimed to systematically elucidate phenotypic and transcriptional changes in infiltrating myeloid cells during carcinogenesis and tumor progression in a genetic mouse model of pancreatic cancer. Using murine pancreatic myeloid cells isolated from the genetic mouse model at different time points during carcinogenesis, we examined both established markers of macrophage polarization using RT-PCR and FACS as well as transcriptional changes focusing on miRNA profiling. Myeloid cells isolated during carcinogenesis showed a simultaneous increase of established markers of M1 and M2 polarization during carcinogenesis, indicating that phenotypic changes of myeloid cells during carcinogenesis do not follow the established M1/M2 classification. MiRNA profiling revealed distinct regulations of several miRNAs already present in myeloid cells infiltrating pre-invasive PanIN lesions. Among them miRNA-21 was significantly increased in myeloid cells surrounding both PanIN lesions and invasive cancers. Functionally, miRNA-21-5p and -3p altered expression of the immune-modulating cytokines CXCL-10 and CCL-3 respectively. Our data indicate that miRNAs are dynamically regulated in infiltrating myeloid cells during carcinogenesis and mediate their functional phenotype by facilitating an immune-suppressive tumor-promoting micro-milieu.

Screening miRNAs for early diagnosis of colorectal cancer by small RNA deep sequencing and evaluation in a Chinese patient population

PURPOSE

This study aims to screen microRNAs (miRNAs), for an early diagnosis of colorectal cancer, by deep sequencing and evaluation of total miRNAs using clinical samples from a Chinese patient population.

METHODS

Total small RNAs from normal colonic mucosa, colonic adenomas, and colorectal cancer tissues were prepared for miRNA analysis by deep sequencing. The sequencing data were then analyzed by bioinformatics for candidate diagnostic miRNAs, which were further validated for their up- or downregulation status.

RESULTS

Comparison of cancer tissues with normal mucosa identified 99 upregulated and 90 downregulated miRNAs. Comparison of adenomas and normal mucosa found 114 upregulated and 107 downregulated miRNAs. Comparison of cancer and adenoma tissues found 70 upregulated and 27 downregulated miRNAs. Selected up- and downregulated miRNAs were validated for their expressions in 12 cases of patients with cancer and polyps. Specifically, for the upregulated miRNAs, miR-18a-5p and miR-21-3p were significantly upregulated in adenomas and cancer tissues, compared with the normal mucosa; miR-135b-5p, miR-17-5p, miR-182-5p, miR-200a-5p, and miR-200c-3p were significantly upregulated in cancer tissues compared to the normal mucosa, but their differential expression was not significant in adenoma tissues when compared with the normal mucosa. miR-183-5p and miR-96-5p were significantly upregulated in adenoma tissues when compared with normal mucosa, but these differences were not significant in cancer tissues when compared to normal mucosa. For the downregulated miRNAs, miR-133a-3p was significantly downregulated in both adenoma and cancer tissues when compared to normal mucosa; miR-204-5p, miR-125b-5p, miR-139-5p, miR-100-5p, and miR-30a-5p were significantly downregulated in cancer tissues compared to the normal mucosa, but their differential expression was not significant in adenoma tissue compared to normal mucosa.

CONCLUSION

The findings of this study show that a number of miRNAs might be important in the diagnosis and prognosis of colorectal cancer in Chinese patients using the method of small RNA deep sequencing. Upregulation of miR-18a-5p and miR-21-3p or downregulation of miR-133a-3p in adenoma and cancer tissues may serve as an index for early screening of colorectal cancer. Other miRNAs, such as miR-135b-5p, miR-17-5p, miR-182-5p, miR-200a-5p, miR-200c-3p, miR-183-5p, and miR-96-5p, which were either up- or downregulated, in cancer tissues, but not in adenoma tissues, have limited significance in early diagnosis. Further study is needed to determine a screening index with diagnostic value.

L1 cell adhesion molecule as a therapeutic target in cancer

L1 cell adhesion molecule (L1CAM) is the prototype member of the L1-family of closely related neural adhesion molecules. L1CAM is differentially expressed in the normal nervous system as well as pathological tissues and displays a wide range of biological activities. In human malignancies, L1CAM plays a vital role in tumor growth, invasion and metastasis. Recently, increasing evidence has suggested that L1CAM exerts a variety of functions at different steps of tumor progression through a series of signaling pathways. In addition, L1CAM has been identified as a promising target for cancer therapy by using synthetic and natural inhibitors. In this review, we provide an up-to-date overview of the role of L1CAM involved in cancers and the rationale for L1CAM as a novel molecular target for cancer therapy.

L1-CAM and N-CAM: From Adhesion Proteins to Pharmacological Targets

L1 cell adhesion molecule (L1-CAM) and neural cell adhesion molecule (N-CAM), key members of the immunoglobulin-like CAM (Ig-CAM) family, were first recognized to play critical roles in surface interactions of neurons, by binding with each other and with extracellular matrix (ECM) proteins. Subsequently, adhesion was recognized to include signaling due to both activation of β-integrin, with the generation of intracellular cascades, and integration with the surface cytoskeleton. The importance of the two Ig-CAMs was revealed by their activation of the tyrosine kinase receptors of fibroblast growth factor (FGF), epidermal growth factor (EGF), and nerve growth factor (NGF). Based on these complex signaling properties, L1-CAM and N-CAM have become of great potential pharmacological interest in neurons and cancers. Treatment of neurodegenerative disorders and cognitive deficits of neurons is aimed to increase the cell Ig-CAM tone, possibly provided by synthetic/mimetic peptides. In cancer cells, where Ig-CAMs are often overexpressed, the proteins are employed for prognosis. The approaches to therapy are based on protein downregulation, antibodies, and adoptive immunotherapy.

MiR-21: an environmental driver of malignant melanoma?

Since the mid-1950’s, melanoma incidence has been rising steadily in industrialized Caucasian populations, thereby pointing to the pivotal involvement of environmental factors in melanomagenesis. Recent evidence underlines the crucial role of microRNA (miR) signaling in cancer initiation and progression. Increased miR-21 expression has been observed during the transition from a benign melanocytic lesion to malignant melanoma, exhibiting highest expression of miR-21. Notably, common BRAF and NRAS mutations in cutaneous melanoma are associated with increased miR-21 expression. MiR-21 is an oncomiR that affects critical target genes of malignant melanoma, resulting in sustained proliferation (PTEN, PI3K, Sprouty, PDCD4, FOXO1, TIPE2, p53, cyclin D1), evasion from apoptosis (FOXO1, FBXO11, APAF1, TIMP3, TIPE2), genetic instability (MSH2, FBXO11, hTERT), increased oxidative stress (FOXO1), angiogenesis (PTEN, HIF1α, TIMP3), invasion and metastasis (APAF1, PTEN, PDCD4, TIMP3). The purpose of this review is to provide translational evidence for major environmental and individual factors that increase the risk of melanoma, such as UV irradiation, chemical noxes, air pollution, smoking, chronic inflammation, Western nutrition, obesity, sedentary lifestyle and higher age, which are associated with increased miR-21 signaling. Exosomal miR-21 induced by extrinsic and intrinsic stimuli may be superimposed on mutation-induced miR-21 pathways of melanoma cells. Thus, oncogenic miR-21 signaling may be the converging point of intrinsic and extrinsic stimuli driving melanomagenesis. Future strategies of melanoma treatment and prevention should thus aim at reducing the burden of miR-21 signal transduction.