MicroRNA-124 Enhances Dopamine Receptor Expression and Neuronal Proliferation in Mouse Models of Parkinson's Disease via the Hedgehog Signaling Pathway by Targeting EDN2.

Recent studies have elaborated on the concept that a number of microRNAs (miRNAs) have a potential effect on the pathogenesis and development of Parkinson's disease (PD). PD is recognized as a common progressive bradykinetic disorder that results from the death of dopaminergic neurons in the substantia nigra. The purpose of this study was to explore whether microRNA-124 (miR-124) affected dopamine receptor (DAR) expression and neuronal proliferation and apoptosis in the 1-methyl-4-pheny-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse models of PD. The targeting relationship of miR-124 and EDN2 was confirmed through bioinformatic predictions and dual-luciferase reporter assay. The expression of miR-124 and EDN2 was altered to assess their effect on the expression of DAR in the substantia nigra and isolated neurons, as well as the neuronal proliferation and apoptosis rate. The obtained results implied that the treatments of miR-124 mimic and si-EDN2 resulted in elevated expressions of Glil, SHH, PTCH1, DAT, DRD1, and DRD2. However, these treatments facilitated neuronal proliferation and suppressed neuronal apoptosis, corresponding to reduced expression of caspase-3 and Bax, as well as increased levels of Bcl-2 expression. These results were discovered to be achieved through the activation of the Hedgehog signaling pathway. With this taken into account, our study demonstrated that miR-124 overexpression promoted DAR expression and neuronal proliferation and suppressed neuronal apoptosis by downregulating EDN2 via activating the Hedgehog signaling pathway.

Chalcogen-substitution modulated supramolecular chirality and gas sensing properties in perylenediimides.

We present the modulation of van der Waals interactions to further adjust supramolecular chirality by incorporation of S and Se into the bay region. These chalcogen atom-mediated supramolecular interactions were transferred to nanostructures and affected the gas responses of devices. This study will facilitate the development of smart materials with modulated handedness in materials science.

A miRNA-based classification of renal cell carcinoma subtypes by PCR and in situ hybridization.

Renal cell carcinoma (RCC) constitutes an array of morphologically and genetically distinct tumors the most prevalent of which are clear cell, papillary, and chromophobe RCC. Accurate distinction between the typically benign-behaving renal oncocytoma and RCC subtypes is a frequent challenge for pathologists. This is critical for clinical decision making. Subtypes also have different survival outcomes and responses to therapy. We extracted RNA from ninety formalin-fixed paraffin-embedded (FFPE) tissues (27 clear cell, 29 papillary, 19 chromophobe, 4 unclassified RCC and 11 oncocytomas). We quantified the expression of six miRNAs (miR-221, miR-222, miR-126, miR-182, miR-200b and miR-200c) by qRT-PCR, and by in situ hybridization in an independent set of tumors. We developed a two-step classifier. In the first step, it uses expression of either miR-221 or miR-222 to distinguish the clear cell and papillary subtypes from chromophobe RCC and oncocytoma (miR-221 AUC: 0.96, 95% CI: 0.9132-1.014, p < 0.0001 and miR-222 AUC: 0.91, 95% CI: 0.8478-0.9772, p < 0.0001). In the second step, it uses miR-126 to discriminate clear cell from papillary RCC (AUC: 1, p < 0.0001) and miR-200b to discriminate chromophobe RCC from oncocytoma (AUC: 0.95, 95% CI: 0.8933-1.021, p < 0.0001). In situ hybridization showed a nuclear staining pattern. miR-126, miR-222 and miR-200b were significantly differentially expressed between the subtypes by in situ hybridization. miRNA expression could distinguish RCC subtypes and oncocytoma. miRNA expression assessed by either PCR or in situ hybridization can be a clinically useful diagnostic tool to complement morphologic renal tumor classification, improving diagnosis and patient management.

Stroma-derived extracellular vesicles deliver tumor-suppressive miRNAs to pancreatic cancer cells.

The biology of tumor-associated stroma (TAS) in pancreatic ductal adenocarcinoma (PDAC) is not well understood. The paradoxical observation that stroma-depletion strategies lead to progression of PDAC reinforced the need to critically evaluate the functional contribution of TAS in the initiation and progression of PDAC. PDAC and TAS cells are unique in their expression of specific miRNAs, and this specific miRNA expression pattern alters host to tumor microenvironment interactions. Using primary human pancreatic TAS cells and primary xenograft PDAC cells co-culture, we provide evidence of miRNA trafficking and exchanging between TAS and PDAC cells, in a two-way, cell-contact independent fashion, via extracellular vesicles (EVs) transportation. Selective packaging of miRNAs into EVs led to enrichment of stromal specific miR-145 in EVs secreted by TAS cells. Exosomes, but not microvesicles, derived from human TAS cells demonstrated a tumor suppressive role by inducing PDAC cell apoptosis. This effect was mitigated by anti-miR-145 sequences. Our data suggest that TAS-derived miRNAs are delivered to adjacent PDAC cells via exosomes and suppress tumor cell growth. These data highlight that TAS cells secrete exosomes carrying tumor suppressive genetic materials, a possible anti-tumor capacity. Future work of the development of patient-derived exosomes could have therapeutic implications for unresectable PDAC.

Expression analysis of microRNA as prognostic biomarkers in colorectal cancer.

microRNA (miRNA) based biomarkers have unique advantages due to their critical regulatory function, superior stability, and relatively small number compared to mRNAs. A number of miRNAs play key roles in colon cancer stem cell chemoresistance and have clinical potential as prognostic biomarkers. The purpose of this study is to systematically validate the prognostic potential of miRNAs in colorectal cancer. In this study, we validated the prognostic potential of a panel of miRNAs using 205 stage II, III, and IV colorectal cancer specimens by qRT-PCR analysis. We cross validated our results using The Cancer Genome Atlas (TCGA) database. Many of the miRNAs we investigated have been functionally validated to be important in contributing to chemoresistance to 5-fluorouracil (5-FU) based chemotherapy. We determined that miR-16 is the most consistent miRNA for expression normalization in colorectal cancer. We have validated several miRNAs (miR-15b, miR-215, miR-145, miR-192, let-7g) that are significantly associated with progression free survival (PFS) and/or overall survival (OS) of colorectal cancer patients independent of tumor stage and age at diagnosis. These 5 miRNAs are significantly associated with OS of colorectal cancer even after tumor location (left side vs. right side) is adjusted for. Furthermore, the prognostic value of let-7g for overall survival was independently validated using the RNA-Seq results from TCGA colorectal cancer database. These results, taken together, establish a solid foundation towards miRNA based precision management of colorectal cancer.

Inhibition of colorectal cancer stem cell survival and invasive potential by hsa-miR-140-5p mediated suppression of Smad2 and autophagy.

Colorectal cancer (CRC) is the third highest mortality cancer in the United States and frequently metastasizes to liver and lung. Smad2 is a key element downstream of the TGF-ß signaling pathway to regulate cancer metastasis by promoting epithelial to mesenchymal transition and maintaining the cancer stem cell (CSC) phenotype. In this study, we show that hsa-miR-140-5p directly targets Smad2 and overexpression of hsa-miR-140-5p in CRC cell lines decreases Smad2 expression levels, leading decreased cell invasion and proliferation, and increasing cell cycle arrest. Ectopic expression of hsa-miR-140-5p in colorectal CSCs inhibited CSC growth and sphere formation in vitro by disrupting autophagy. We have systematically identified targets of hsa-miR-140-5p involved in autophagy. Furthermore, overexpression of hsa-miR-140-5p in CSCs abolished tumor formation and metastasis in vivo. In addition, there is a progressive loss of hsa-miR-140-5p expression from normal colorectal mucosa to primary tumor tissues, with further reduction in liver metastatic tissues. Higher hsa-miR-140 expression is significantly correlated with better survival in stage III and IV colorectal cancer patients.The functional and clinical significance of hsa-miR-140-5p suggests that it is a key regulator in CRC progression and metastasis, and may have potential as a novel therapeutic molecule to treat CRC.

Helical supramolecular aggregates of sugar-based perylene dyes: the effect of core-substituted groups.

Here we have shown that it is possible to modulate π-π stacking, hydrogen bonds and hydrophobic and hydrophilic interactions to further adjust the supramolecular helicity by simply changing the core-substituted group. These modulated supramolecular interactions provide a new pathway to the controlled production of helical superstructures.

miR-129 as a novel therapeutic target and biomarker in gastrointestinal cancer.

In the last decade, cancer research efforts in the field of noncoding microRNA (miRNA) have been growing exponentially. miRNA-based therapeutics have been tested in both preclinical and clinical settings, and miRNA-based cancer diagnostics and prognostics have moved into clinics to help better manage cancer treatment. A growing body of evidence in recent literature suggests miRNA-129 plays important roles in gastrointestinal cancer, including gastric, colorectal, hepatocellular carcinoma, and esophageal cancer. In this review, we focus on accumulating evidence demonstrating the key roles that miRNA-129 plays in tumorigenesis, disease progression, chemoresistance, proliferation, and cell cycle control. Understanding the emerging roles and mechanisms of miRNA-129 in cancer will help us realize the therapeutic and diagnostic/prognostic potential.

Circulating microRNA testing for the early diagnosis and follow-up of colorectal cancer patients.

Early detection of colorectal cancer (CRC) is key for prevention and the ability to impact long-term survival of CRC patients. However, the compliance rate of recommended colonoscopy for the population aged from 50 to 75 years is only 50-75 % in the US. A highly sensitive and specific non-invasive test is needed to enhance CRC management. As for late-stage patients, a non-invasive prognostic biomarker is also critical for improving patient treatment protocols. The discovery that non-coding microRNAs (miRNAs) are stable in body fluids such as plasma, serum and exosomes presents the opportunity to develop novel strategies, taking advantage of circulating miRNAs as early diagnostic biomarkers of CRC. The goal of using circulating miRNA-based prognostic biomarkers for CRC patients has been pursued extensively. In this review, we will try to cover the major recent advancements at the frontier of this research area.

Keratin 17 in premalignant and malignant squamous lesions of the cervix: proteomic discovery and immunohistochemical validation as a diagnostic and prognostic biomarker.

Most previously described immunohistochemical markers of cervical high-grade squamous intraepithelial lesion (HSIL) and squamous cell carcinoma may help to improve diagnostic accuracy but have a minimal prognostic value. The goals of the current study were to identify and validate novel candidate biomarkers that could potentially improve diagnostic and prognostic accuracy for cervical HSIL and squamous cell carcinoma. Microdissected tissue sections from formalin-fixed paraffin-embedded normal ectocervical squamous mucosa, low-grade squamous intraepithelial lesion (LSIL), HSIL and squamous cell carcinoma sections were analyzed by mass spectrometry-based shotgun proteomics for biomarker discovery. The diagnostic specificity of candidate biomarkers was subsequently evaluated by immunohistochemical analysis of tissue microarrays. Among 1750 proteins identified by proteomic analyses, keratin 4 (KRT4) and keratin 17 (KRT17) showed reciprocal patterns of expression in the spectrum of cases ranging from normal ectocervical squamous mucosa to squamous cell carcinoma. Immunohistochemical studies confirmed that KRT4 expression was significantly decreased in squamous cell carcinoma compared with the other diagnostic categories. By contrast, KRT17 expression was significantly increased in HSIL and squamous cell carcinoma compared with normal ectocervical squamous mucosa and LSIL. KRT17 was also highly expressed in immature squamous metaplasia and in endocervical reserve cells but was generally not detected in mature squamous metaplasia. Furthermore, high levels of KRT17 expression were significantly associated with poor survival of squamous cell carcinoma patients (Hazard ratio=14.76, P=0.01). In summary, both KRT4 and KRT17 expressions are related to the histopathology of the cervical squamous mucosa; KRT17 is highly overexpressed in immature squamous metaplasia, in HSIL, and in squamous cell carcinoma and the level of KRT17 in squamous cell carcinoma may help to identify patients who are at greatest risk for cervical cancer mortality.

Prognostic significance of miR-194 in endometrial cancer.

Endometrial cancer (EC) is the leading malignant tumor occurring in the female genital tract and some subtypes are highly invasive and metastatic. miRNAs are small non-coding RNAs that have a broad impact on cancer progression. In particular, miR-194 regulates epithelial to mesenchymal transition (EMT) by suppressing the expression of BMI-1 in EC. In this retrospective study, the clinical significance of miR-194 was investigated in archival EC specimens. We extracted total RNA from thirty-two EC samples and quantified the expression level of miR-194. We discovered that the expression level of miR-194 was significantly (P = 0.03) lower in type I EC patients with more advanced stage. In addition, patients with higher miR-194 levels have better prognosis than those with lower miR-194 levels (P = 0.0067; Cut-off value of miR-194 = 0.3). These results indicate that miR-194 has potential to serve as prognostic biomarker for EC patients.

Clinical significance of long intergenic noncoding RNA-p21 in colorectal cancer.

BACKGROUND: Long intergenic noncoding RNAs (lincRNAs) have been shown to be novel regulators for both transcription and posttranscriptional/translation. One of them, lincRNA-p21, was regulated by p53 and contributed to apoptosis in mouse embryonic fibroblasts. However, the impact of such regulation on colorectal cancer (CRC) remains to be determined. METHODS: Total RNA was extracted from CRC cell lines and snap fresh frozen CRC samples from 2 CRC patient cohorts. The expression of lincRNA-p21 was quantified by quantitative real-time polymerase chain reaction analysis. RESULTS: We discovered that the expression level of lincRNA-p21 was increased by elevated wild-type p53 induced by nutlin-3 in HCT-116 colon cancer cells. The expression level of lincRNA-p21 was significantly (P = .0208) lower in CRC tumor tissue when compared with the paired normal tissue from the same patient. There was no significant correlation of lincRNA-p21 with p53 status (wild-type vs. mutant). Tumors in the rectum showed a higher level of lincRNA-p21 than tumors in the colon (P = .00005). In addition, lincRNA-p21 in patients with stage III tumors was significantly higher than in those with stage I tumors (P = .007). Elevated levels of lincRNA-p21 were significantly associated with higher pT (P = .037 between pT 2 and 3) and vascular invasion (P = .017). CONCLUSIONS: These results indicate that lincRNA-p21 may contribute to CRC disease progression.

MicroRNA: a third dimension in autophagy.

Autophagy is a catabolic process that allows cellular macromolecules to be broken down and recycled into metabolic precursors. It is a highly conserved, critical process, allowing cells to gain survival advantages under various stress situations due to growth and environmental changes. In the past few years, mounting evidence indicates that the post-transcriptional and translational controls mediated by non-coding miRNAs contribute significantly to autophagy in cancer. Such acute modulation of protein synthesis mediated by miRNAs provides cells with advantages in response to starvation, genotoxic stress and hypoxia. In this review, we highlight some of the important discoveries and molecular insights of miRNAs in regulating autophagy based on various cancer models.

The annexin A2/S100A10 system in health and disease: emerging paradigms.

Since its discovery as a src kinase substrate more than three decades ago, appreciation for the physiologic functions of annexin A2 and its associated proteins has increased dramatically. With its binding partner S100A10 (p11), A2 forms a cell surface complex that regulates generation of the primary fibrinolytic protease, plasmin, and is dynamically regulated in settings of hemostasis and thrombosis. In addition, the complex is transcriptionally upregulated in hypoxia and promotes pathologic neoangiogenesis in the tissues such as the retina. Dysregulation of both A2 and p11 has been reported in examples of rodent and human cancer. Intracellularly, A2 plays a critical role in endosomal repair in postarthroplastic osteolysis, and intracellular p11 regulates serotonin receptor activity in psychiatric mood disorders. In human studies, the A2 system contributes to the coagulopathy of acute promyelocytic leukemia, and is a target of high-titer autoantibodies in patients with antiphospholipid syndrome, cerebral thrombosis, and possibly preeclampsia. Polymorphisms in the human ANXA2 gene have been associated with stroke and avascular osteonecrosis of bone, two severe complications of sickle cell disease. Together, these new findings suggest that manipulation of the annexin A2/S100A10 system may offer promising new avenues for treatment of a spectrum of human disorders.

Implications of microRNAs in colorectal cancer development, diagnosis, prognosis, and therapeutics.

MicroRNAs (miRNAs) are a class of non-coding small RNAs with critical regulatory functions as post-transcriptional regulators. Due to the fundamental importance and broad impact of miRNAs on multiple genes and pathways, dysregulated miRNAs have been associated with human diseases, including cancer. Colorectal cancer (CRC) is among the most deadly diseases, and miRNAs offer a new frontier for target discovery and novel biomarkers for both diagnosis and prognosis. In this review, we summarize the recent advancement of miRNA research in CRC, in particular, the roles of miRNAs in CRC stem cells, epithelial-to-mesenchymal transition, chemoresistance, therapeutics, diagnosis, and prognosis.

Annexin A2 promotes glioma cell invasion and tumor progression.

Gliomas are highly invasive, lethal brain tumors. Tumor-associated proteases play an important role in glioma progression. Annexin A2 is overexpressed in many cancers and correlates with increased plasmin activity on the tumor cell surface, which mediates degradation of extracellular matrix and promotes neoangiogenesis to facilitate tumor growth. In this study, we used two glioma cell lines, mouse GL261-EGFP and rat C6/LacZ, as well as stable clones transfected with an annexin A2 knockdown construct. We find that the annexin A2 knockdown decreased glioma cell migration in vitro and decreased membrane-bound plasmin activity. In vivo, we injected the glioma cells into the rodent brain and followed glioma progression. Knockdown of annexin A2 in glioma cells decreased tumor size and slowed tumor progression, as evidenced by decreased invasion, angiogenesis, and proliferation, as well as increased apoptosis in the tumor tissue of the annexin A2 knockdown group. Moreover, we report that the levels of expression of annexin A2 in human glioma samples correlate with their degree of malignancy. Together, our findings demonstrate that inhibition of annexin A2 expression in glioma cells could become a new target for glioma therapy.

Microglia/macrophages promote glioma progression.

Gliomas are highly aggressive and accompanied by numerous microglia/macrophages (MG/MP) in and about the tumor. Little is known about what MG/MP do in this setting, or whether modulating MG/MP activation might affect glioma progression. Here, we used a glioma-microglia in culture system to establish the effects the tumor and microglia have on each other. We assessed glioma progression in vivo after MG/MP ablation or in the setting of exaggerated MG/MP activation. We show that glioma cells activate microglia but inhibit their phagocytic activities. Local ablation of MG/MP in vivo decreased tumor size and improved survival curves. Conversely, pharmacological activation of MG/MP increased glioma size through stimulating tumor proliferation and inhibiting apoptosis. In agreement with recent reports, expression of the chemokine CCL21 is enhanced after MG/MP activation and correlates with tumor growth. Taken together, our findings demonstrate that inhibition of MG/MP activation may constitute a new and effective contribution towards suppressing glioma proliferation.