MicroRNA-137 inhibits BMP7 to enhance the epithelial-mesenchymal transition of breast cancer cells

Regulation of Inflammasome by microRNAs in Triple-Negative Breast Cancer: New Opportunities for Therapy

During the past decade, researchers have investigated the molecular mechanisms of breast cancer initiation and progression, especially triple-negative breast cancer (TNBC), in order to identify specific biomarkers that could serve as feasible targets for innovative therapeutic strategies development. TNBC is characterized by a dynamic and aggressive nature, due to the absence of estrogen, progesterone and human epidermal growth factor 2 receptors. TNBC progression is associated with the dysregulation of nucleotide-binding oligomerization domain-like receptor and pyrin domain-containing protein 3 (NLRP3) inflammasome, followed by the release of pro-inflammatory cytokines and caspase-1 dependent cell death, termed pyroptosis. The heterogeneity of the breast tumor microenvironment triggers the interest of non-coding RNAs' involvement in NLRP3 inflammasome assembly, TNBC progression and metastasis. Non-coding RNAs are paramount regulators of carcinogenesis and inflammasome pathways, which could help in the development of efficient treatments. This review aims to highlight the contribution of non-coding RNAs that support inflammasome activation and TNBC progression, pointing up their potential for clinical applications as biomarkers for diagnosis and therapy.

MicroRNAs: A Link between Mammary Gland Development and Breast Cancer

Breast cancer is among the most common cancers in women, second to skin cancer. Mammary gland development can influence breast cancer development in later life. Processes such as proliferation, invasion, and migration during mammary gland development can often mirror processes found in breast cancer. MicroRNAs (miRNAs), small, non-coding RNAs, can repress post-transcriptional RNA expression and can regulate up to 80% of all genes. Expression of miRNAs play a key role in mammary gland development, and aberrant expression can initiate or promote breast cancer. Here, we review the role of miRNAs in mammary development and breast cancer, and potential parallel roles. A total of 32 miRNAs were found to be expressed in both mammary gland development and breast cancer. These miRNAs are involved in proliferation, metastasis, invasion, and apoptosis in both processes. Some miRNAs were found to have contradictory roles, possibly due to their ability to target many genes at once. Investigation of miRNAs and their role in mammary gland development may inform about their role in breast cancer. In particular, by studying miRNA in development, mechanisms and potential targets for breast cancer treatment may be elucidated.

The expression of BMP, integrin, ZEB2 in ovarian high-grade serous carcinoma in relation with lymph node metastasis

Ovarian cancer (OC) is clinically important because it is diagnosed late and has metastasis when it is diagnosed. Mortality risk increases 2.75 times in the presence of lymph node (LN) metastasis. During metastasis, many molecules including BMPs originated from stroma, and tumor cells participate through transcription factors and integrins for cytoskeleton regulation during cell migration. We hypothesized an inverse correlation between BMP2 and BMP7 along with changes in ZEB2, and integrin α5β1 in high-grade OCs in relation to LN metastasis. The BMP2 immunoreactivity was strong along with strong ZEB2 and weak integrins' immunoreactivity in samples with LN metastasis. Strong immunoreactivity of BMP7 was accompanied by strong immunoreactivity of integrins in the samples without LN metastasis. Study results showed BMP2's strong positive immunoreactivity and weak BMP7 immunoreactivity in tumor cells with a significantly weak inverse correlation. This inverse correlation should be considered as both BMPs have different effects in the window of cancer progression and invasion.

Response to neoadjuvant chemotherapy in breast cancer: do microRNAs matter?

BACKGROUND

Conventionally, breast cancer (BC) prognosis and prediction of response to therapy are based on TNM staging, histological and molecular subtype, as well as genetic alterations. The role of various epigenetic factors has been elucidated in carcinogenesis. However, it is still unknown to what extent miRNAs affect the response to neoadjuvant chemotherapy (NACT). This pilot study is focused on evaluating the role of miR-34a, miR-124a, miR-155, miR-137 and miR-373 in response to NACT.

METHODS

That was a prospective study enrolling 34 patients with histologically confirmed BC of II-III stages. The median age of patients was 53 (47-59.8) years old, 70.6% of whom were HR-positive. MiRs levels were measured in the primary tumor before and after NACT. The response to therapy was assessed after surgery using the Miller-Payne scoring system. To establish the role of miRs in modulating response to NACT the Cox model was applied for analysis.

RESULTS

BC demonstrated a great variability of miRs expression before and after NACT with no strong links to tumor stage and molecular subtype. Only miR-124a and miR-373 demonstrated differential expression between malignant and normal breast tissues before and after therapy though these distinctions did not impact response to NACT. Besides miR-124a and miR-137 levels after NACT were found to be dependent on HR status. While miR-124a levels increased (p = 0.021) in the tumor tissue, the expression of miR-137 was downregulated (p = 0.041) after NACT in HR positive BC.

CONCLUSIONS

The study revealed differences in miR-124a and miR-373 expression after NACT in primary BC tissues. Although miRs levels did not impact the response to NACT, we found miR-124a and miR-137 levels to be related to hormonal sensitivity of BC.

MicroRNA-1298-5p inhibits the tumorigenesis of breast cancer by targeting E2F1

Studies performed in the last two decades have identified microRNA (miR)-1298-5p to display tumor-suppressive functions in several types of malignancy. In addition, the regulatory role of E2F transcription factor 1 (E2F1) has been reported in multiple types of cancer, including breast cancer (BC). However, whether miR-1298-5p participates in BC progression and whether a regulatory association exists between miR-1298-5p and E2F1 remains to be explored. The present study aimed to determine the role of miR-1298-5p and its interaction with E2F1 in BC. The expression of miR-1298-5p and E2F1 was examined by reverse transcription-quantitative PCR and western blot assays. The viability and proliferative capacity of BC cells were evaluated by Cell Counting Kit-8 and 5-bromo-2′-deoxyuridine assays, respectively. The apoptotic rate was assessed by the caspase-3 activity assay and flow cytometry; the protein expression levels of vimentin and E-cadherin were evaluated by western blotting. In addition, the adhesive and migratory abilities of BC cells were determined by conducting cell adhesion and wound healing assay, respectively. The target relationship between miR-1298-5p and E2F1 was validated by the luciferase reporter assay. The results of the present study revealed that the levels of miR-1298-5p were downregulated in BC tissues and cells compared with those in normal breast tissues and cells, respectively. In addition, miR-1298-5p was demonstrated to inhibit the proliferation, adhesion and migration of BC cells and to promote BC cell apoptosis. E2F1 was verified as a target gene of miR-1298-5p using the luciferase reporter assay. Additionally, E2F1 exhibited an opposite expression pattern compared with that of miR-1298-5p in BC tissues. Furthermore, the downregulation of miR-1298-5p in BC cells was reversed by silencing E2F1. Overall, the results of the present study suggested that miR-1298-5p repressed BC cell proliferation, adhesion and migration, and enhanced BC cell apoptosis by downregulating E2F1.

Construction and Comparison of ceRNA Regulatory Network for Different Age Female Breast Cancer

Studies have shown the difference appearing among the prognosis of patients in different age groups. However, the molecular mechanism implicated in this disparity have not been elaborated. In this study, expression profiles of female breast cancer (BRCA) associated mRNAs, lncRNAs and miRNAs were downloaded from the TCGA database. The sample were manually classified into three groups according to their age at initial pathological diagnosis: young (age ≤ 39 years), elderly (age ≥ 65 years), and intermediate (age 40-64 years). lncRNA-miRNA-mRNA competitive endogenous RNA (ceRNA) network was respectively constructed for different age BRCA. Then, the biological functions of differentially expressed mRNAs (DEmRNAs) in ceRNA network were further investigated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Finally, survival analysis was used to identify prognostic biomarkers for different age BRCA patients. We identified 13 RNAs, 38 RNAs and 40 RNAs specific to patients aged ≤ 39 years, aged 40-64 years, and aged ≥ 65 years, respectively. Furthermore, the unique pathways were mainly enriched in cytokine-cytokine receptor interaction in patients aged 40-64 years, and were mainly enriched in TGF-beta signaling pathway in patients aged ≥ 65 years. According to the survival analysis, AGAP11, has-mir-301b, and OSR1 were respectively functioned as prognostic biomarkers in young, intermediate, and elderly group. In summary, our study identified the differences in the ceRNA regulatory networks and provides an effective bioinformatics basis for further understanding of the pathogenesis and predicting outcomes for different age BRCA.

Hypoxia-Induced miR-137 Inhibition Increased Glioblastoma Multiforme Growth and Chemoresistance Through LRP6

Purpose

Glioblastoma multiforme (GBM) is one of the deadliest tumors, which is involved in numerous dysregulated microRNAs including miR-137. However, the mechanism of how miR-137 suppression associated with cancer progression and chemoresistance still remains to be elucidated.

Methods

Quantitative reverse transcriptase-PCR (qRT-PCR), DNA methylation analysis, cell proliferation assay, flow cytometric analysis, invasion assay, in situ tumor formation experiment were performed to test the expression levels and functions of miR-137 in GBM. Bioinformatics analysis, luciferase reporter assay, qRT-PCR, immunoblotting, immunofluorescence, and immunohistochemistry assay were used to identify and verify the target of miR-137.

Results

We found that miR-137 was downregulated in primary and recurrent GBM compared with normal brain tissues. Overexpression of miR-137 inhibited cell invasion and enhanced cell chemosensitivity to temozolomide (TMZ) by directly targeting low-density lipoprotein receptor-related protein 6 (LRP6) in GBM. Forced expression of LRP6 cDNA without its 3’-UTR region partly restored the effects of miR-137 in vitro and in vivo. Hypoxia-induced miR-137 methylation was responsible for the miR-137 suppression, leading to the cell chemoresistance and poor prognosis of GBM.

Conclusions

These findings demonstrated the detailed molecular mechanism of miR-137 in regulating GBM growth and chemoresistance in hypoxia microenvironment, suggesting the potentiality of miR-137 as a therapeutic target for GBM.

Bioinformatic analysis and in vitro validation of a five-microRNA signature as a prognostic biomarker of hepatocellular carcinoma

Background

Existing research has identified correlations between numerous microRNAs (miRNAs) and the prognosis of hepatocellular carcinoma (HCC). However, the role of a combination of miRNAs in predicting HCC survival requires further elucidation.

Methods

miRNA expression profiles and clinical data from HCC patients were downloaded from The Cancer Genome Atlas (TCGA). Differentially expressed (DE) miRNAs in tumor versus normal samples were identified. All HCC patients were randomly assigned to a training cohort or a validation cohort at a ratio of 1 to 1. A least absolute shrinkage and selection operator (LASSO) Cox regression model was subsequently employed to establish the miRNA signature. The constructed miRNA signature was then developed and validated.

Results

In total, 127 DE miRNAs were detected between HCC and paracancerous tissue using HCC RNA sequencing (RNA-Seq) data extracted from TCGA database. LASSO Cox regression generated a five-miRNA signature consisting of has-mir-105-2, has-mir-9-3, has-mir-137, has-mir-548f-1, and has-mir-561 in the training cohort. This risk model was significantly related to survival (P=5.682e-6). Log-rank tests and multivariate Cox regression analyses revealed the five-miRNA signature as an independent prognostic indicator [HR =3.285, 95% confidence interval (CI): 1.737–6.213], with the area under curve (AUC) of the miRNA signature being 0.728. The effects of the miRNA signature were further confirmed in the validation cohort and in the OncomiR Cancer Database and Gene Expression Omnibus (GEO) dataset. Functional enrichment analysis revealed the potential effects of the five-miRNA signature in tumor-related biological pathways and processes. Cell Counting Kit-8, Transwell, and wound healing assays, were used to evaluate the role of has-mir-137 in HCC cell proliferation and migration in vitro.

Conclusions

We established a novel five-miRNA signature which reliably predicted prognosis in HCC patients and which could be used to assist in both strategic counseling and personalized management in HCC.

BMP7 is a candidate gene for reproductive traits in Yorkshire sows

Bone morphogenetic protein 7 (BMP7) is of the BMP subfamily, and has effects on female fertility by regulating steroidogenesis, granulosa cell states, and follicular development. In the present study, there was assessment of the combined genotypes formed by the three variants within the 3'-UTR of BMP7 gene as associations with sow reproductive functions. The 3'-UTR of the BMP7 gene of pigs was identified using the 3' RACE assay, and its full-length sequence was found to be 1538 bp in length. Multiple RNA regulatory elements were detected in this region, luciferase activity assays were performed and results indicated miR-22-3p affects BMP7 by directly binding to the miRNA response element in the 3'-UTR (c.2358-2382). In addition, two novel complete linkage variants, c.2256 G > C and a 7-bp indel (c.2259-2265), were identified within the 3'-UTR of the BMP7 gene of pigs. Importantly, combined genotypes with these two novel variants and c.1569A > G, a variant previously identified in the BMP7 3'-UTR of pigs, were associated with sow reproductive traits, including the total number of piglets born, number of dead piglets at birth, and litter weight in the Yorkshire pig population studies. Results from the present study confirm that BMP7 is a candidate gene for the reproductive traits in Yorkshire sows.

Anti‑proliferative effect of honokiol on SW620 cells through upregulating BMP7 expression via the TGF‑β1/p53 signaling pathway

Honokiol (HNK), a natural pharmaceutically active component extracted from magnolia bark, has been used for clinical treatments and has anti‑inflammatory, antiviral and antioxidative effects. In recent years, anticancer research has become a major hotspot. However, the underlying molecular mechanisms of how HNK inhibits colorectal cancer have remained elusive. The present study focused on elucidating the effects of HNK on the expression of bone morphogenetic protein (BMP)7 and its downstream interaction with transforming growth factor (TGF)‑β1 and p53 in colon cancer. In in vitro assays, cell viability, cell cycle distribution and apoptosis were examined using Cell Counting Kit‑8, flow cytometry and reverse transcription‑quantitative PCR, respectively. In addition, the expression of BMP7, TGF‑β1 and relevant signaling proteins was determined by western blot analysis. In vivo, the anticancer effect of HNK was assessed in xenografts in nude mice. Furthermore, immunohistochemistry was performed to evaluate the association between BMP7 and TGF‑β1 expression in colon cancer. The results indicated that HNK inhibited the proliferation of colon cancer cell lines, with SW620 cells being more sensitive than other colon cancer cell lines. Furthermore, HNK markedly promoted the expression of BMP7 at the mRNA and protein level. Exogenous BMP7 potentiated the effect of HNK on SW620 cells, while knocking down BMP7 inhibited it. As a downstream mechanism, HNK increased the expression of TGF‑β1 and p53, which was enhanced by exogenous BMP7 in SW620 cells. In addition, immunohistochemical analysis indicated a positive association between BMP7 and TGF‑β1 expression. Hence, the present results suggested that HNK is a promising agent for the treatment of colon cancer and enhanced the expression TGF‑β1 and p53 through stimulating BMP7 activity via the non‑canonical TGF‑β signaling pathway.

MicroRNA‑137 exerts protective effects on hypoxia‑induced cell injury by inhibiting autophagy/mitophagy and maintaining mitochondrial function in breast cancer stem‑like cells

Breast cancer stem‑like cells (BCSCs) have been identified and proven to play critical roles in tumorigenesis and progression. Hypoxia is a common pathologic feature of breast cancer and potentially, at least in part, regulates the initiation, progression, and recurrence of breast cancer. However, less is known about how hypoxia regulates BCSCs. As several well‑known microRNAs respond to hypoxia, we aimed to determine how hypoxia regulates the physiological processes of BCSCs by regulating the corresponding microRNAs. As expected, microRNA‑137 (miRNA‑137 or miR‑137) was downregulated upon hypoxic exposure, indicating that it may play critical roles in BCSCs. Introduction of miR‑137 mimics promoted cell cycle entry and inhibited hypoxia‑induced cell apoptosis as determined by cell cycle assay and apoptosis assay. By detecting mitochondrial reactive oxygen species (ROS), it was found that miR‑137 inhibited ROS accumulation induced by hypoxic exposure and thus suppressed cell apoptosis. Introduction of miR‑137 mimics under hypoxia inhibited mitophagy/autophagy by targeting FUN14 domain containing 1 (Fundc1) and thus promoted mitochondrial functions, including mitochondrial mass, ATP synthesis and mitochondrial transcriptional activity, which was similar to the effects of Fundc1 knockdown by specific siRNA. Based on these observations, we hypothesized that the survival of BCSCs under hypoxia was mediated by miR‑137 by regulating mitochondrial dysfunction. We demonstrated here that the introduction of exogenous miR‑137 promoted mitochondrial function, indicating that it may be a potential therapeutic target in BCSCs.

Potential miRNAs for miRNA-Based Therapeutics in Breast Cancer

MicroRNAs (miRNAs) are small non-coding RNAs that can post-transcriptionally regulate the genes involved in critical cellular processes. The aberrant expressions of oncogenic or tumor suppressor miRNAs have been associated with cancer progression and malignancies. This resulted in the dysregulation of signaling pathways involved in cell proliferation, apoptosis and survival, metastasis, cancer recurrence and chemoresistance. In this review, we will first (i) provide an overview of the miRNA biogenesis pathways, and in vitro and in vivo models for research, (ii) summarize the most recent findings on the roles of microRNAs (miRNAs) that could potentially be used for miRNA-based therapy in the treatment of breast cancer and (iii) discuss the various therapeutic applications.

miR-137: A Novel Therapeutic Target for Human Glioma

MicroRNA (miR)-137 is highly expressed in the brain and plays a crucial role in the development and prognosis of glioma. In this review, we aim to summarize the latest findings regarding miR-137 in glioma cell apoptosis, proliferation, migration, invasion, angiogenesis, drug resistance, and cancer treatment. In addition, we focus on the identified miR-137 targets and pathways in the occurrence and development of glioma. Finally, future implications for the diagnostic and therapeutic potential of miR-137 in glioma were discussed.

The Role of NLRP3 Inflammasome Activation in the Epithelial to Mesenchymal Transition Process During the Fibrosis

Fibrosis is considered a complex form of tissue damage commonly present in the end stage of many diseases. It is also related to a high percentage of death, whose predominant characteristics are an excessive and abnormal deposition of fibroblasts and myofibroblasts -derived extracellular matrix (ECM) components. Epithelial-to-mesenchymal transition (EMT), a process in which epithelial cells gradually change to mesenchymal ones, is a major contributor in the pathogenesis of fibrosis. The key mediator of EMT is a multifunctional cytokine called transforming growth factor-β (TGF-β) that acts as the main inducer of the ECM assembly and remodeling through the phosphorylation of Smad2/3, which ultimately forms a complex with Smad4 and translocates into the nucleus. On the other hand, the bone morphogenic protein-7 (BMP-7), a member of the TGF family, reverses EMT by directly counteracting TGF-β induced Smad-dependent cell signaling. NLRP3 (NACHT, LRR, and PYD domains-containing protein 3), in turn, acts as cytosolic sensors of microbial and self-derived molecules and forms an immune complex called inflammasome in the context of inflammatory commitments. NLRP3 inflammasome assembly is triggered by extracellular ATP, reactive oxygen species (ROS), potassium efflux, calcium misbalance, and lysosome disruption. Due to its involvement in multiple diseases, NLRP3 has become one of the most studied pattern-recognition receptors (PRRs). Nevertheless, the role of NLRP3 in fibrosis development has not been completely elucidated. In this review, we described the relation of the previously mentioned fibrosis pathway with the NLRP3 inflammasome complex formation, especially EMT-related pathways. For now, it is suggested that the EMT happens independently from the oligomerization of the whole inflammasome complex, requiring just the presence of the NLRP3 receptor and the ASC protein to trigger the EMT events, and we will present different pieces of research that give controversial point of views.

TGFβ Family Signaling Pathways in Pluripotent and Teratocarcinoma Stem Cells' Fate Decisions: Balancing Between Self-Renewal, Differentiation, and Cancer

The transforming growth factor-β (TGFβ) family factors induce pleiotropic effects and are involved in the regulation of most normal and pathological cellular processes. The activity of different branches of the TGFβ family signaling pathways and their interplay with other signaling pathways govern the fine regulation of the self-renewal, differentiation onset and specialization of pluripotent stem cells in various cell derivatives. TGFβ family signaling pathways play a pivotal role in balancing basic cellular processes in pluripotent stem cells and their derivatives, although disturbances in their genome integrity induce the rearrangements of signaling pathways and lead to functional impairments and malignant transformation into cancer stem cells. Therefore, the identification of critical nodes and targets in the regulatory cascades of TGFβ family factors and other signaling pathways, and analysis of the rearrangements of the signal regulatory network during stem cell state transitions and interconversions, are key issues for understanding the fundamental mechanisms of both stem cell biology and cancer initiation and progression, as well as for clinical applications. This review summarizes recent advances in our understanding of TGFβ family functions in naїve and primed pluripotent stem cells and discusses how these pathways are involved in perturbations in the signaling network of malignant teratocarcinoma stem cells with impaired differentiation potential.

MicroRNAs in breast cancer: Roles, functions, and mechanism of actions

Breast cancer is one of the most lethal malignancies in women in the world. Various factors are involved in the development and promotion of the malignancy; most of them involve changes in the expression of certain genes, such as microRNAs (miRNAs). MiRNAs can regulate signaling pathways negatively or positively, thereby affecting tumorigenesis and various aspects of cancer progression, particularly breast cancer. Besides, accumulating data demonstrated that miRNAs are a novel tool for prognosis and diagnosis of breast cancer patients. Herein, we will review the roles of these RNA molecules in several important signaling pathways, such as transforming growth factor, Wnt, Notch, nuclear factor-κ B, phosphoinositide-3-kinase/Akt, and extracellular-signal-regulated kinase/mitogen activated protein kinase signaling pathways in breast cancer.

A set of microRNAs coordinately controls tumorigenesis, invasion, and metastasis

The capabilities for invasion and metastasis underlie the mortality and morbidity of most forms of human cancer. Currently, there are no effective therapies specifically targeting these cancer phenotypes, in part due to the paucity of dominant mutations that induce them, and indeed losses of suppressors of invasion and metastasis are increasingly recognized as determinants, posing challenges for drug development. Our results implicate epigenetic gene regulation mediated by elevated expression of distinct microRNAs in orchestrating invasion and metastasis, evidently by abrogating distinctive suppressor mechanisms. Therefore, targeting such microRNAs holds promise as a strategy to combat malignant cancers with epigenetically disrupted tumor suppressor mechanisms.

MicroRNA-mediated gene regulation has been implicated in various diseases, including cancer. This study examined the role of microRNAs (miRNAs) during tumorigenesis and malignant progression of pancreatic neuroendocrine tumors (PanNETs) in a genetically engineered mouse model. Previously, a set of miRNAs was observed to be specifically up-regulated in a highly invasive and metastatic subtype of mouse and human PanNET. Using functional assays, we now implicate different miRNAs in distinct phenotypes: miR-137 stimulates tumor growth and local invasion, whereas the miR-23b cluster enables metastasis. An algorithm, Bio-miRTa, has been developed to facilitate the identification of biologically relevant miRNA target genes and applied to these miRNAs. We show that a top-ranked miR-137 candidate gene, Sorl1, has a tumor suppressor function in primary PanNETs. Among the top targets for the miR-23b cluster, Acvr1c/ALK7 has recently been described to be a metastasis suppressor, and we establish herein that it is down-regulated by the miR-23b cluster, which is crucial for its prometastatic activity. Two other miR-23b targets, Robo2 and P2ry1, also have demonstrable antimetastatic effects. Finally, we have used the Bio-miRTa algorithm in reverse to identify candidate miRNAs that might regulate activin B, the principal ligand for ALK7, identifying thereby a third family of miRNAs—miRNA-130/301—that is congruently up-regulated concomitant with down-regulation of activin B during tumorigenesis, suggestive of functional involvement in evasion of the proapoptotic barrier. Thus, dynamic up-regulation of miRNAs during multistep tumorigenesis and malignant progression serves to down-regulate distinctive suppressor mechanisms of tumor growth, invasion, and metastasis.

Variants in BMP7 and BMP15 3'-UTRs Associated with Reproductive Traits in a Large White Pig Population

Bone morphogenetic protein 7 (BMP7) and BMP15, which encode members of the BMP family, have been identified by whole-genome resequencing as breeding-related genes that overlap with a known quantitative trait locus for reproductive traits. In this study, we investigated the effects of variants at the BMP7 and BMP15 gene loci on sow reproductive traits. We isolated 669 and 1213 bp sequences of the 3’-untranslated region (3’-UTR) of the porcine BMP7 and BMP15 genes, respectively, and detected several RNA regulatory elements, such as miRNA response elements and AU-rich elements. Pooled DNA sequencing identified two novel point mutations (viz., BMP7 c.1569A>G and BMP15 c.2366G>A) in the 3’-UTR. Association analysis showed that the c.1569A>G polymorphism was associated with the litter weight trait in a Large White pig population. Furthermore, analysis of the combined genetic effects revealed that AA/GA and AG/GG were the favorable combined genotypes for the total number of piglets born (TNB) and the total number of piglets born alive (NBA), whereas. Together, our findings confirm that BMP7 and BMP15 are candidate genes for porcine reproductive performance.

Small nucleolar RNA host gene 1 promotes development and progression of colorectal cancer through negative regulation of miR-137

Small nucleolar RNA host gene 1 (SNHG1) is critical in the progression of cancers. However, the mechanism by which SNHG1 regulates the progression of colorectal cancer (CRC) remains unclear. Expressions of SNHG1 and miR‐137 in CRC tissues and cell lines were evaluated by quantitative real‐time polymerase chain reaction. A luciferase reporter gene assay was conducted to investigate miR‐137 target. Additionally, RNA pull‐down assay was performed to explore the physical association between miR‐137, SNHG1, and RNA induced silencing complex (RISC). Cell cycling and invasion were examined by flow cytometry (FCM) and transwell assays. The in vivo carcinogenic activity of SNHG1 was examined using murine xenograft models. Expression of RICTOR, serine/threonine kinase 1 (AKT), serum and glucocorticoid‐inducible kinase 1 (SGK1), p70S6K1, and LC3II/LC3I ratio was examined by Western blot analysis. SNHG1 upregulation was observed in CRC tissues and cell lines, which was associated with the lymph node metastasis, advanced TNM stage and poorer prognosis. SNHG1 increased RICTOR level in CRC via sponging miR‐137. In addition, SNHG1 silencing inhibited CRC cell proliferation and migration in vitro and in vivo. SNHG1 regulated RICTOR expression by sponging miR‐137 and promoted tumorgenesis in CRC.

Expression of Bone Morphogenetic Protein-7 Significantly Correlates With Non-small Cell Lung Cancer Progression and Prognosis: A Retrospective Cohort Study

Background

Bone morphogenetic protein-7 (BMP-7) is a signaling molecule belonging to the transforming growth factor-β superfamily. Recent studies have demonstrated that BMP-7 is expressed in various human cancers and plays an important role in the progression of their cancers. The purpose of this study was to investigate the clinicopathologic and prognostic impact of BMP-7 expression in clinical samples of non-small cell lung cancer.

Methods

This study enrolled 160 patients with non-small cell lung cancer who underwent complete resection. Expression of BMP-7 in cancer tissue was evaluated by immunohistochemistry. Correlations between expression of BMP-7 and clinicopathologic factors and prognosis were analyzed.

Results

In non-small cell lung cancer, BMP-7 expression was identified not only in cell membranes but also in the cytoplasm of cancer cells. Expression of BMP-7 correlated with p-T (P = .047), N factor (P = .013), and p-stage (P = .046). Overall survival rate was significantly lower in the BMP-7-positive group than in the BMP-7-negative group (P = .004). Multivariate analysis indicated that BMP-7 expression was one of the independent prognosis factors of overall survival (P = .021). Furthermore, among patients with postoperative recurrence (n = 58), the BMP-7-positive group (n = 29) had a significantly poorer prognosis than the BMP-7-negative group (n = 29) (P = .012).

Conclusions

Expression of BMP-7 in non-small cell lung cancer was correlated with clinicopathologic factors and poorer prognosis. BMP-7 expression may be a useful predictor of aggressive activity of tumor behavior and postoperative outcome of patients with non-small cell lung cancer.

The transcriptome landscape of the carcinogenic treatment response in the blind mole rat: insights into cancer resistance mechanisms

Background

Spalax, the blind mole rat, developed an extraordinary cancer resistance during 40 million years of evolution in a subterranean, hypoxic, thus DNA damaging, habitat. In 50 years of Spalax research, no spontaneous cancer development has been observed. The mechanisms underlying this resistance are still not clarified. We investigated the genetic difference between Spalax and mice that might enable the Spalax relative resistance to cancer development. We compared Spalax and mice responses to a treatment with the carcinogen 3-Methylcholantrene, as a model to assess Spalax’ cancer-resistance.

Results

We compared RNA-Seq data of untreated Spalax to Spalax with a tumor and identified a high number of differentially expressed genes. We filtered these genes by their expression in tolerant Spalax that resisted the 3MCA, and in mice, and found 25 genes with a consistent expression pattern in the samples susceptible to cancer among species.

Contrasting the expressed genes in Spalax with benign granulomas to those in Spalax with malignant fibrosarcomas elucidated significant differences in several pathways, mainly related to the extracellular matrix and the immune system. We found a central cluster of ECM genes that differ greatly between conditions.

Further analysis of these genes revealed potential microRNA targets.

We also found higher levels of gene expression of some DNA repair pathways in Spalax than in other murines, like the majority of Fanconi Anemia pathway.

Conclusion

The comparison of the treated with the untreated tissue revealed a regulatory complex that might give an answer how Spalax is able to restrict the tumor growth. By remodeling the extracellular matrix, the possible growth is limited, and the proliferation of cancer cells was potentially prevented. We hypothesize that this regulatory cluster plays a major role in the cancer resistance of Spalax. Furthermore, we identified 25 additional candidate genes that showed a distinct expression pattern in untreated or tolerant Spalax compared to animals that developed a developed either a benign or malignant tumor. While further study is necessary, we believe that these genes may serve as candidate markers in cancer detection.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5417-z) contains supplementary material, which is available to authorized users.

Biological effects of BMP7 on small-cell lung cancer cells and its bone metastasis

Small-cell lung cancer (SCLC) is typically fatal if untreated. It is characterized by early and widespread metastases, and has the ability to rapidly develop resistance to chemotherapy. Bone morphogenetic protein 7 (BMP7), a member of the BMP family of signaling molecules, has been implicated in various types of cancer, particularly prostate cancer and breast cancer. However, there is little knowledge of the function of BMP7 in SCLC. The aim of the present study was to investigate the biological function of recombinant human (rh)BMP7 on SCLC cells and the underlying molecular basis for this regulatory mechanism. The effect of rhBMP7 on SCLC cell lines and associated signaling pathways was investigated. Results suggested that rhBMP7 significantly inhibited the proliferation, motility and invasion of SBC-3 and SBC-5 cells. However, rhBMP7 exhibited no effect on the apoptosis of SBC-5 cells, but promoted apoptosis of SBC-3 cells. Furthermore, cell cycle analysis revealed that rhBMP7 was able to increase the proportion of cells in G1 phase and decrease the S phase proportion. Total and membrane BMP receptor (BMPR)IA and BMPRIB were highly expressed in SBC-5 cells, whereas cytoplasmic BMPRIA and BMPRIB expression was higher in SBC-3 cells. However, activin A receptor type I expression was higher in SBC-3 cells in total and cytoplasmic proteins. Furthermore, following stimulation with rhBMP7, Smad2, Smad4 and p21 were downregulated. We hypothesized that rhBMP7 inhibited the progressiveness of SCLC cells by inducing G1 phase arrest and inhibiting S phase entry. The results of the present study indicated that BMP7 serves a key function in regulating the progression of SCLC.

The down-regulation of microRNA-137 contributes to the up-regulation of retinoblastoma cell proliferation and invasion by regulating COX-2/PGE2 signaling

MicroRNA-137 (miR-137) plays an important role in the development and progression of many types of human cancers; however, the role of miR-137 in retinoblastoma (RB) remains unclear. In this study, we aimed to investigate the functional significance and molecular mechanisms of miR-137 in RB. We reported that miR-137 was frequently down-regulated in RB tissues and cell lines. The overexpression of miR-137 inhibited RB cell proliferation and invasion, while the suppression of miR-137 promoted RB cell proliferation and invasion. Bioinformatic analysis predicted that cyclooxygenase-2 (COX-2) was a potential target gene of miR-137, which was validated by a dual-luciferase reporter assay. Moreover, our results showed that miR-137 negatively regulated the expression of COX-2 and the production of prostaglandin E2 (PGE2) in RB cells. The knockdown of COX-2 suppressed the proliferation and invasion of RB cells as well as the production of PGE2. The overexpression of COX-2 significantly reversed the inhibitory effect of miR-137 overexpression on RB cell proliferation and invasion. Taken together, these results suggest that miR-137 suppresses the proliferation and invasion of RB cells by targeting COX-2/PGE2. Our study reveals a tumor suppressive role of miR-137 in the progression of RB and suggests miR-137 as a potentially effective therapeutic target for the treatment of RB.

MiR-129 regulates growth and invasion by targeting MAL2 in papillary thyroid carcinoma

MAL2, a member of the MAL proteolipid family, is essential for raft-mediated transport. In this study, we investigated the roles and underlying mechanism of MAL2 in the development of papillary thyroid carcinoma (PTC). Up-regulation of MAL2 was found in human PTC tissues and significantly correlated with poor overall survival (OS). Knockdown of MAL2 dramatically suppressed PTC cell proliferation and invasion in vitro and inhibited tumor growth in vivo. We further found that miR-129 suppressed the expression of MLA through directly binding to the 3' untranslated region (3' UTR). While forced miR-129 expression suppressed growth and invasion of PTC cells, re-expression of MAL2 rescued these effects. Taken together, our data indicated that MAL2 acted as an oncogene and was negatively regulated by miR-129, supporting the potential therapeutic strategy against PTC by targeting miR-129-MAL2 axis.

Deregulation of Negative Controls on TGF-β1 Signaling in Tumor Progression

The multi-functional cytokine transforming growth factor-β1 (TGF-β1) has growth inhibitory and anti-inflammatory roles during homeostasis and the early stages of cancer. Aberrant TGF-β activation in the late-stages of tumorigenesis, however, promotes development of aggressive growth characteristics and metastatic spread. Given the critical importance of this growth factor in fibrotic and neoplastic disorders, the TGF-β1 network is subject to extensive, multi-level negative controls that impact receptor function, mothers against decapentaplegic homolog 2/3 (SMAD2/3) activation, intracellular signal bifurcation into canonical and non-canonical pathways and target gene promotor engagement. Such negative regulators include phosphatase and tensin homologue (PTEN), protein phosphatase magnesium 1A (PPM1A), Klotho, bone morphogenic protein 7 (BMP7), SMAD7, Sloan-Kettering Institute proto-oncogene/ Ski related novel gene (Ski/SnoN), and bone morphogenetic protein and activin membrane-bound Inhibitor (BAMBI). The progression of certain cancers is accompanied by loss of expression, overexpression, mislocalization, mutation or deletion of several endogenous repressors of the TGF-β1 cascade, further modulating signal duration/intensity and phenotypic reprogramming. This review addresses how their aberrant regulation contributes to cellular plasticity, tumor progression/metastasis and reversal of cell cycle arrest and discusses the unexplored therapeutic value of restoring the expression and/or function of these factors as a novel approach to cancer treatment.

MicroRNA Expression Analysis of In Vitro Dedifferentiated Human Pancreatic Islet Cells Reveals the Activation of the Pluripotency-Related MicroRNA Cluster miR-302s

β-cell dedifferentiation has been recently suggested as an additional mechanism contributing to type-1 and to type-2 diabetes pathogenesis. Moreover, several studies demonstrated that in vitro culture of native human pancreatic islets derived from non-diabetic donors resulted in the generation of an undifferentiated cell population. Additional evidence from in vitro human β-cell lineage tracing experiments, demonstrated that dedifferentiated cells derive from β-cells, thus representing a potential in vitro model of β-cell dedifferentiation. Here, we report the microRNA expression profiles analysis of in vitro dedifferentiated islet cells in comparison to mature human native pancreatic islets. We identified 13 microRNAs upregulated and 110 downregulated in islet cells upon in vitro dedifferentiation. Interestingly, among upregulated microRNAs, we observed the activation of microRNA miR-302s cluster, previously defined as pluripotency-associated. Bioinformatic analysis indicated that miR-302s are predicted to target several genes involved in the control of β-cell/epithelial phenotype maintenance; accordingly, such genes were downregulated upon human islet in vitro dedifferentiation. Moreover, we uncovered that cell–cell contacts are needed to maintain low/null expression levels of miR-302. In conclusion, we showed that miR-302 microRNA cluster genes are involved in in vitro dedifferentiation of human pancreatic islet cells and inhibits the expression of multiple genes involved in the maintenance of β-cell mature phenotype.

High YBX1 expression indicates poor prognosis and promotes cell migration and invasion in nasopharyngeal carcinoma

Y-box binding protein-1 (YBX1) is a multifunctional protein and often acts as an indicator of poor prognosis in cancers. Increasing evidence has shown that the levels of YBX1 protein were closely associated with multidrug resistance, relapse, metastasis and poor prognosis in cancers. However, its role in nasopharyngeal carcinoma (NPC) metastasis remains unknown. In our study, we discovered that the expression of YBX1 was increased in nasopharyngeal carcinoma tissues. YBX1 protein levels positively correlated with T stage and metastasis of NPC patients. Moreover, expression of YBX1 was negatively correlated with membrane E-cadherin levels and positively correlated with Vimentin expression. In vitro, the expression of YBX1 was closely related to the invasive and migratory ability of nasopharyngeal carcinoma cells. Knockdown of YBX1 inhibited migration and invasion in 5-8F cells, and over-expression of YBX1 promoted CNE1 cells migration and invasion. Transforming growth factor-β1 (TGF-β1) treatment led to epithelial-to-mesenchymal transition (EMT) in CNE1 cells accompanied by elevated YBX1 expression. On the contrary, knockdown of YBX1 partially inhibited the TGF-β1-induced CNE1 cell migration, together with changes of EMT-associated markers. Our study revealed that TGF-β1/YBX1 signaling might be one of novel mechanisms mediating EMT in NPC, providing a new target for the treatment of nasopharyngeal carcinoma.