Dynamically decreased miR-671-5p expression is associated with oncogenic transformation and radiochemoresistance in breast cancer.

BACKGROUND: Understanding the molecular alterations associated with breast cancer (BC) progression may lead to more effective strategies for both prevention and management. The current model of BC progression suggests a linear, multistep process from normal epithelial to atypical ductal hyperplasia (ADH), to ductal carcinoma in situ (DCIS), and then invasive ductal carcinoma (IDC). Up to 20% ADH and 40% DCIS lesions progress to invasive BC if left untreated. Deciphering the molecular mechanisms during BC progression is therefore crucial to prevent over- or under-treatment. Our previous work demonstrated that miR-671-5p serves as a tumor suppressor by targeting Forkhead box protein M1 (FOXM1)-mediated epithelial-to-mesenchymal transition (EMT) in BC. Here, we aim to explore the role of miR-671-5p in the progression of BC oncogenic transformation and treatment. METHODS: The 21T series cell lines, which were originally derived from the same patient with metastatic BC, including normal epithelia (H16N2), ADH (21PT), primary DCIS (21NT), and cells derived from pleural effusion of lung metastasis (21MT), and human BC specimens were used. Microdissection, miRNA transfection, dual-luciferase, radio- and chemosensitivity, and host-cell reactivation (HCR) assays were performed. RESULTS: Expression of miR-671-5p displays a gradual dynamic decrease from ADH, to DCIS, and to IDC. Interestingly, the decreased expression of miR-671-5p detected in ADH coexisted with advanced lesions, such as DCIS and/or IDC (cADH), but not in simple ADH (sADH). Ectopic transfection of miR-671-5p significantly inhibited cell proliferation in 21NT (DCIS) and 21MT (IDC), but not in H16N2 (normal) and 21PT (ADH) cell lines. At the same time, the effect exhibited in time- and dose-dependent manner. Interestingly, miR-671-5p significantly suppressed invasion in 21PT, 21NT, and 21MT cell lines. Furthermore, miR-671-5p suppressed FOXM1-mediated EMT in all 21T cell lines. In addition, miR-671-5p sensitizes these cell lines to UV and chemotherapeutic exposure by reducing the DNA repair capability. CONCLUSIONS: miR-671-5p displays a dynamic decrease expression during the oncogenic transition of BC by suppressing FOXM1-mediated EMT and DNA repair. Therefore, miR-671-5p may serve as a novel biomarker for early BC detection as well as a therapeutic target for BC management.

miR-638 mediated regulation of BRCA1 affects DNA repair and sensitivity to UV and cisplatin in triple-negative breast cancer.

INTRODUCTION: Triple-negative breast cancer (TNBC) represents 15 to 20% of all types of breast cancer; however, it accounts for a large number of metastatic cases and deaths, and there is still no effective treatment. The deregulation of microRNAs (miRNAs) in breast cancer has been widely reported. We previously identified that miR-638 was one of the most deregulated miRNAs in breast cancer progression. Bioinformatics analysis revealed that miR-638 directly targets BRCA1. The aim of this study was to investigate the role of miR-638 in breast cancer prognosis and treatment. METHODS: Formalin-fixed, paraffin-embedded (FFPE) breast cancer samples were microdissected into normal epithelial and invasive ductal carcinoma (IDC) cells, and total RNA was isolated. Several breast cancer cell lines were used for the functional analysis. miR-638 target genes were identified by TARGETSCAN-VERT 6.2 and miRanda. The expression of miR-638 and its target genes was analyzed by real-time qRT-PCR and Western blotting. Dual-luciferase reporter assay was employed to confirm the specificity of miR-638 target genes. The biological function of miR-638 was analyzed by MTT chemosensitivity, matrigel invasion and host cell reactivation assays. RESULTS: The expression of miR-638 was decreased in IDC tissue samples compared to their adjacent normal controls. The decreased miR-638 expression was more prevalent in non-TNBC compared with TNBC cases. miR-638 expression was significantly downregulated in breast cancer cell lines compared to the immortalized MCF-10A epithelial cells. BRCA1 was predicted as one of the direct targets of miR-638, which was subsequently confirmed by dual-luciferase reporter assay. Forced expression of miR-638 resulted in a significantly reduced proliferation rate as well as decreased invasive ability in TNBC cells. Furthermore, miR-638 overexpression increased sensitivity to DNA-damaging agents, ultraviolet (UV) and cisplatin, but not to 5-fluorouracil (5-FU) and epirubicin exposure in TNBC cells. Host cell reactivation assays showed that miR-638 reduced DNA repair capability in post UV/cisplatin-exposed TNBC cells. The reduced proliferation, invasive ability, and DNA repair capabilities are associated with downregulated BRCA1 expression. CONCLUSIONS: Our findings suggest that miR-638 plays an important role in TNBC progression via BRCA1 deregulation. Therefore, miR-638 might serve as a potential prognostic biomarker and therapeutic target for breast cancer.

Role of ß-catenin and TCF/LEF family members in transcriptional activity of HIV in astrocytes.

The Wnt/ß-catenin pathway is involved in diverse cell functions governing development and disease. ß-Catenin, a central mediator of this pathway, binds to members of the TCF/LEF family of transcription factors to modulate hundreds of genes. Active Wnt/ß-catenin/TCF-4 signaling plays a significant role in repression of HIV-1 replication in multiple cell targets, including astrocytes. To determine the mechanism by which active ß-catenin/TCF-4 leads to inhibition of HIV replication, we knocked down ß-catenin or TCF/LEF members in primary astrocytes and astrocytomas transiently transfected with an HIV long terminal repeat (LTR)-luciferase reporter that contained an integrated copy of the HIV LTR-luciferase construct. Knockdown of either ß-catenin or TCF-4 induced LTR activity by 2- to 3-fold under both the episomal and integrated conditions. This knockdown also increased presence of serine 2-phosphorylated RNA polymerase II (Pol II) on the HIV LTR as well as enhanced its processivity. Knockdown of ß-catenin/TCF-4 also impacted tethering of other transcription factors on the HIV promoter. Specifically, knockdown of TCF-4 enhanced binding of C/EBPß, C/EBPδ, and NF-κB to the HIV LTR, while ß-catenin knockdown increased binding of C/EBPß and C/EBPδ but had no effect on NF-κB. Approximately 150 genes in astrocytes were impacted by ß-catenin knockdown, including genes involved in inflammation/immunity, uptake/transport, vesicular transport/exocytosis, apoptosis/cellular stress, and cytoskeleton/trafficking. These findings indicate that modulation of the ß-catenin/TCF-4 axis impacts the basal level of HIV transcription in astrocytes, which may drive low level/persistent HIV in astrocytes that can contribute to ongoing neuroinflammation, and this axis also has profound effects on astrocyte biology.

Changes in GIP gene expression following bariatric surgery.

BACKGROUND: After bariatric surgery, there is a significant improvement in type 2 diabetes (T2D). T2D has been linked to incretins, including glucose-dependent insulinotropic polypeptide (GIP). Analysis of bariatric surgery patients may help to understand the link between GIP and T2D. METHODS: Twenty-three morbidly obese patients underwent Roux-en-Y gastric bypass (RYGB) or gastric banding. Overall, there were 12 RYGB (5 T2D; 7 nondiabetic) patients and 11 gastric band (7 T2D; 4 nondiabetic) patients. Preoperative and postoperative blood samples were collected. Total RNA was extracted, cDNA synthesized, and real-time quantitative PCR were used to quantify gene expression. Student's t test was used for statistical analysis. RESULTS: Postoperatively, T2D resolved or improved in 83.3 % (10/12) of the diabetic patients. Six (4 RYGB, 2 bands) patients discontinued hypoglycemic medications and four (3 RYGB, 1 band) patients discontinued the majority of their hypoglycemic agents. The remaining two diabetic patients (bands) showed no improvement. Postoperative GIP gene expression increased 4.36-fold (p = 0.02) in diabetic RYGB patients, whereas diabetic band patients increased 1.4-fold (p = 0.25). All diabetic patients with either resolution or improvement of T2D, had a 3.4-fold increase (p = 0.01) but nonresponders decreased 0.69-fold (p = 0.41). Nondiabetic RYGB patients increased 2.21-fold (p = 0.07) versus a 0.81-fold (p = 0.37) decrease of nondiabetic band patients. CONCLUSIONS: This is one of the initial studies that show a significant increase in GIP gene expression following a RYGB. This increase correlates with the clinical resolution of T2D. The anatomical changes after RYGB may account for these changes. Based on this data, GIP may be a key peptide in the "foregut hypothesis" for resolution of T2D.

Resistin expression correlates with steatohepatitis in morbidly obese patients.

BACKGROUND: Morbidly obese patients are at risk for nonalcoholic steatohepatitis (NASH) even in the absence of risk factors for liver disease. Unfortunately, NASH is usually not clinically evident, and a definitive, noninvasive test for NASH does not exist. Resistin, a cytokine originating from adipose tissue, is involved in insulin resistance and also initiates proinflammatory signaling from hepatic stellate cells. This study explores the relationship between resistin expression and liver pathology in bariatric surgery patients. METHODS: Blood samples from 30 patients undergoing bariatric surgery were collected. Total RNA was extracted and cDNA was synthesized. Quantitative RT-PCR was used to quantify relative gene expression using 18s rRNA gene as an internal control. Wedge liver biopsies from these patients were sectioned and stained. Based on a previously published scoring method, biopsies were assigned an overall NASH severity score and subscores for steatosis, inflammation, and fibrosis. Results were analyzed by using Student's t test. RESULTS: Resistin mRNA levels ranged from 0.5 to 9.7. A group of five patients with very high resistin expression (>4) was identified. These patients had a significantly higher average NASH score compared with the rest of the group (7.9 vs. 4.48, p = 0.019). Steatosis and inflammation scores were significantly higher in the high-resistin group (p < 0.05 for both comparisons). There also was a trend toward higher fibrosis score in this group, which approached statistical significance (p = 0.051). CONCLUSIONS: In morbidly obese patients, high resistin expression in serum is associated with hepatic steatosis, inflammation, and fibrosis. The development of elevated resistin expression may represent a link between obesity and the onset of steatohepatitis.

The most likely but largely ignored triggering factor for breast (or all) cancer invasion.

Breast cancer development and progression are believed to be a sequential process, from normal to hyperplastic, to in situ, and to invasive and metastatic stages. Given that over 90% of cancer deaths are caused by invasive and metastatic lesions, countless factors and multiple theories have been proposed as the triggering factor for the cascade of actions of cancer invasion. However, those factors and theories are largely based on the studies of cell lines or animal models. In addition, corresponding interventions based on these factors and theories have failed to reduce the incidence rate of invasive and metastatic lesions, suggesting that previous efforts may have failed to arm at the right target. Considering these facts and observations, we are proposing "A focal aberrant degeneration in the myoepithelial cell layer (MECL) as the most likely triggering factor for breast cancer invasion". Our hypothesis is based on our recent studies of breast and multiple other cancers. Our commentary provides the rationale, morphologic, immunohistochemical, and molecular data to support our hypotheses. As all epithelium-derived cancers share a very similar architecture, our hypothesis is likely to be applicable to invasion of all cancer types. We believe that human tissue-derived data may provide a more realistic roadmap to guide the clinic practice.

Revelation of p53-independent function of MTA1 in DNA damage response via modulation of the p21 WAF1-proliferating cell nuclear antigen pathway.

Although metastasis-associated protein 1 (MTA1), a component of the nucleosome remodeling and deacetylase (NuRD) complex, is a DNA-damage response protein and regulates p53-dependent DNA repair, it remains unknown whether MTA1 also participates in p53-independent DNA damage response. Here, we provide evidence that MTA1 is a p53-independent transcriptional corepressor of p21(WAF1), and the underlying mechanism involves recruitment of MTA1-histone deacetylase 2 (HDAC2) complexes onto two selective regions of the p21(WAF1) promoter. Accordingly, MTA1 depletion, despite its effect on p53 down-regulation, superinduces p21(WAF1), increases p21(WAF1) binding to proliferating cell nuclear antigen (PCNA), and decreases the nuclear accumulation of PCNA in response to ionizing radiation. In support of a p53-independent role of MTA1 in DNA damage response, we further demonstrate that induced expression of MTA1 in p53-null cells inhibits p21(WAF1) promoter activity and p21(WAF1) binding to PCNA. Consequently, MTA1 expression in p53-null cells results in increased induction of gamma H2AX foci and DNA double strand break repair, and decreased DNA damage sensitivity following ionizing radiation treatment. These findings uncover a new target of MTA1 and the existence of an additional p53-independent role of MTA1 in DNA damage response, at least in part, by modulating the p21(WAF1)-PCNA pathway, and thus, linking two previously unconnected NuRD complex and DNA-damage response pathways.

Downregulation of miR-375 contributes to ERBB2-mediated VEGFA overexpression in esophageal cancer.

Esophageal cancer (EC) is a lethal cancer with an extremely aggressive nature and poor survival rate. However, the molecular mechanisms driving the occurrence and progression of EC are not well understood. MicroRNAs (miRNAs) are small RNA molecules that regulate the expression of protein-coding genes. miRNA-mediated gene regulation plays an important role in EC. By cross-referencing studies from NCBI, we found that microRNA-375 (miR-375) is one of the most frequently downregulated miRNAs in EC. We assessed expression of miR-375 in EC cell lines and primary EC tissues and their matched normal tissues. We found significant downregulation of miR-375 in both cell lines and EC tissues. Forced expression of miR-375 attenuated EC cell proliferation and invasion. Human epidermal growth factor receptor 2 (HER2, ERBB2), a known proto-oncogene, was identified here as one of the potential target genes of miR-375. Ectopic expression of miR-375 significantly suppressed the expression of ERBB2 and subsequently downregulated one of its target genes, vascular endothelial growth factor A (VEGFA), which is related to cancer invasion and metastasis. These findings suggest that miR-375 acts as a tumor suppressor by blocking the ERBB2/VEGFA pathway with the potential to modulate the occurrence and/ or progression of EC.

Differentially Regulated miRNAs and Their Related Molecular Pathways in Lichen Sclerosus.

Lichen sclerosus (LS) is a chronic inflammatory skin disorder with unknown pathogenesis. The aberrant expression of microRNAs (miRNAs) is considered to exert a crucial role in LS. We used the next-generation sequencing technology (RNASeq) for miRNA profiling and Ingenuity Pathway Analysis (IPA) for molecular network analysis. We performed qRT-PCR, miRNA transfection and Matrigel assays for functional studies. We identified a total of 170 differentially expressed miRNAs between female LS and matched adjacent normal tissue using RNASeq, with 119 upregulated and 51 downregulated. Bioinformatics analysis revealed molecular networks that may shed light on the pathogenesis of LS. We verified the expression of a set of miRNAs that are related to autoimmunity, such as upregulated miR-326, miR-142-5p, miR-155 and downregulated miR-664a-3p and miR-181a-3p in LS tissue compared to the matched adjacent normal tissue. The differentially expressed miRNAs were also verified in blood samples from LS patients compared to healthy female volunteers. Functional studies demonstrated that a forced expression of miR-142-5p in human dermal fibroblast PCS-201-010 cells resulted in decreased cell proliferation and migration. These findings suggest that differentially expressed miRNAs may play an important role in LS pathogenesis; therefore, they could serve as biomarkers for LS management.

microRNA-196b promotes esophageal squamous cell carcinogenesis and chemoradioresistance by inhibiting EPHA7, thereby restoring EPHA2 activity.

Esophageal cancer (EC) is extremely aggressive and has a very poor survival rate. Esophageal squamous cell carcinoma (ESCC) accounts for 80% of all ECs worldwide, with the majority of the remaining 20% being esophageal adenocarcinoma (EAC). Due to its occult and insidious presentation, ESCC is typically diagnosed and treated in its advanced stages, thereby limiting the success of present therapeutic modalities. microRNAs (miRNAs) can function as tumor suppressors or oncogenes, playing critical roles in cancer initiation and progression by regulating target genes in oncogenic pathways. In the current study, we demonstrated that microRNA-196b (miR-196b) is one of the most upregulated miRNAs in both ESCC and EAC. miR-196b was overexpressed in ESCC and EAC cell lines, cellular exosomal RNAs, and ESCC tissue samples. Functional studies revealed that miR-196b acted as an oncomiR by directly targeting a tumor suppressor, ephrin type-A receptor 7 (EPHA7). EPHA7 abrogates the activity of ephrin type-A receptor 2 (EPHA2), a key molecule involved in the epithelial-to-mesenchymal transition (EMT) and MAPK/ERK pathways, mediating resistance to UV and chemoradiotherapy in both ESCC and EAC. Taken together, these findings suggest that miR-196b is a strong candidate molecular target for EC treatment.

Reactivation of adiponectin expression in obese patients after bariatric surgery.

BACKGROUND: Bariatric surgery can resolve type 2 diabetes in morbidly obese patients. However, the underlying mechanism is unknown. This study aimed to identify potential biomarkers or molecular pathways that are altered after bariatric surgery in diabetic and nondiabetic patients. METHODS: The study enrolled 17 morbidly obese patients undergoing bariatric surgery. Eight of the patients were diabetic, and nine were nondiabetic. In addition, a control group of four nonobese, nondiabetic volunteers was included. Patient blood samples were drawn before and after the operation. All blood samples were stabilized in Paxgene tubes (PreAnalytix). Total RNA was extracted and purified using the Paxgene Blood RNA Kit. For each sample, 100 ng of total RNA was amplified and labeled using the Ovation RNA Amplification System V2 with the Ovation Whole Blood reagent before hybridization to an Affymetrix Focus array containing more than 8,500 verified genes. Microarray results were analyzed with the GeneSpring GX 10.0 program, which uses an analysis of variance (ANOVA), and verified with real-time quantitative polymerase chain reaction (QPCR) using SYBR green (ABI). RESULTS: Microarray analysis showed that 167 genes were upregulated and 39 were downregulated in the obese diabetic patients. Preoperatively, adiponectin was downregulated 1.5-fold in diabetic versus nondiabetic patients. This was confirmed with quantitative PCR analysis. Preoperatively, morbidly obese patients showed a 3.12-fold downregulation of adiponectin expression versus the control group (p = 0.05). Interestingly, postoperative adiponectin levels were upregulated 2.79-fold (p = 0.02), which is close to the level of the normal control group. CONCLUSIONS: Adiponectin is dysregulated in obese patients and significantly dysregulated in obese diabetic patients. These findings correlate with the association between low levels of adiponectin and a predisposition to insulin resistance or diabetes. The data suggest that reactivation of adiponectin expression may play a part in the resolution of type 2 diabetes after bariatric surgery. Therefore, targeting adiponectin may help to develop alternative treatments for diabetes.

Estrogen Receptor, Progesterone Receptor, and HER2 Receptor Markers in Endometrial Cancer.

Background: Endometrial cancer (EC) is a major gynecologic adenocarcinoma that arises from the endometrium. While the incidence of EC is on the rise worldwide, survivorship and clinical advancement have considerably lagged compared to other cancers. Given the sensitive nature of the endometrium and its high expression of hormone receptors, hormonal therapy has become a favorable alternative treatment compared to highly toxic chemotherapeutics and radiation therapy. Methods: Clinical samples from patients diagnosed with EC were obtained. ER and PR staining were performed according to the S-P kit, and HER2 staining was carried out according to the UltrasensitiveTM S-P immunohistochemistry kit protocol. Chi-square analysis was conducted using the SPSS. P-values of less than 0.05 were taken as an a priori value for statistical significance. Results: Immunohistochemical (IHC) analysis showed the overall positive expression rates of ER, PR, and HER2 to be 59.8%, 75.0%, and 71.1%, respectively. Significant co-expression was found among all three receptors, suggesting a cooperative, synergistic effect. More importantly, we found that ER expression was correlated with FIGO staging and cervical invasion, whereas PR expression was associated with histologic type. No clinicopathologic features were correlated with HER2 expression, but HER2 positivity was inversely associated with the degree of HER2 overexpression. Conclusions: These results suggest that EC is a heterogeneous disease that may not conform to traditional, prototypically defined subtypes. The status of ER, PR, and HER2 receptors may have the potential to serve as prognostic indicators for EC, but further analysis is needed to ascertain their prognostic significance.

Dysregulation of gene expression within the peroxisome proliferator activated receptor pathway in morbidly obese patients.

BACKGROUND: The causes of obesity are multifactorial but may include dysregulation of a family of related genes, such as the peroxisome proliferator activated receptor gamma (PPARgamma). When activated, the PPARgamma pathway promotes lipid metabolism. This study used microarray technology to evaluate differential gene expression profiles in obese patients undergoing bariatric surgery. METHODS: The study enrolled six morbidly obese patients with a body mass index (BMI) exceeding 35 and four nonobese individuals. Blood samples were stabilized in PaxGene tubes (PreAnalytiX), and total RNA was extracted. Next, 100 ng of total RNA was amplified and labeled using the Ovation RNA Amplification System V2 with the Ovation whole-blood reagent (NuGen) before it was hybridized to an Affymetrix (Santa Clara, CA) focus array containing more than 8,500 verified genes. The data were analyzed using an analysis of variance (ANOVA) (p < 0.05) in the GeneSpring program, and potential pathways were identified with the Ingenuity program. Real-time quantitative reverse transcriptase-polymerase chain reaction was used to validate the array data. RESULTS: A total of 97 upregulated genes and 125 downregulated genes were identified. More than a 1.5-fold change was identified between the morbidly obese patients and the control subjects for a cluster of dysregulated genes involving pathways regulating cell metabolism and lipid formation. Specifically, the PPARgamma pathway showed a plethora of dysregulated genes including tumor necrosis factor-alpha (TNFalpha). In morbidly obese patients, TNFalpha expression was increased (upregulated) 1.6-fold. These findings were confirmed using quantitative polymerase chain reaction with a 2.8-fold change. CONCLUSIONS: Microarrays are a powerful tool for identifying biomarkers indicating morbid obesity by analyzing differential gene expression profiles. This study confirms the association of PPARgamma with morbid obesity. Also, these findings in blood support previous work documented in tissue (omentum, liver, and stomach). Based on these findings in blood, the authors plan to explore postoperative changes in gene expression by analyzing blood samples after bariatric surgery. Ultimately, these findings may promote the development of therapeutic agents targeted to specific dysfunctional genes.

Lichen Sclerosus: An autoimmunopathogenic and genomic enigma with emerging genetic and immune targets.

Lichen sclerosus (LS) is an inflammatory dermatosis with a predilection for anogenital skin. Developing lesions lead to vulvar pain and sexual dysfunction, with a significant loss of structural anatomical architecture, sclerosis, and increased risk of malignancy. Onset may occur at any age in both sexes, but typically affects more females than males, presenting in a bimodal fashion among pre-pubertal children and middle-aged adults. A definitive cure remains elusive as the exact pathogenesis of LS remains unknown. A general review of LS, histologic challenges, along with amounting support for LS as an autoimmune disease with preference for a Th1 immune response against a genetic background is summarized. In addition to the classically referenced ECM1 (extracellular matrix protein 1), a following discussion of other immune and genetic targets more recently implicated as causative or accelerant agents of disease, particularly miR-155, downstream targets of ECM1, galectin-7, p53, and epigenetic modifications to CDKN2A, are addressed from the viewpoint of their involvement in three different, but interconnected aspects of LS pathology. Collectively, these emerging targets serve not only as inherently potential therapeutic targets for treatment, but may also provide further insight into this debilitating and cryptic disease.

miR-34b-3p May Promote Antiplatelet Efficiency of Aspirin by Inhibiting Thromboxane Synthase Expression.

Aspirin has been widely used for the prevention of cardiovascular diseases, but its antiplatelet efficiency varies between individuals. The present study aimed to evaluate response to aspirin based on gene profiles as well as potential regulating pathways using human blood samples and cell lines. Platelet function in patients 50 years or older with coronary artery disease on 100 mg/day aspirin was measured by light transmission aggregometry (LTA) of arachidonic acid (AA)-induced platelet aggregation. The expression of eight candidate genes-PTGS1/COX1, PLA2G4A, PLA2G6, PLA2G7, TBXAS1, TBXA2R, PTGIR, and ITGA2B-and the ingredients involved in AA metabolism were analyzed. Our data showed that the expressions of thromboxane A synthase 1 (TBXAS1), thromboxane synthase (TXS), and thromboxane B2 (TXB2) were increased in the upper quartile of platelet aggregation (LTA-AA_Q4) group compared with the lower quartile of platelet aggregation (LTA-AA_Q1) group. Our bioinformatics analysis suggested that TBXAS1 was targeted by miR-34b-3p via binding to its 3'-UTR, which was subsequently verified experimentally. Although overexpression of miR-34b-3p exhibited no apparent effect on cell proliferation, inhibition of miR-34b-3p promoted megakaryocyte viability. Our data demonstrated that the expression of TBXAS1 was higher in the aspirin hyporesponsiveness group than that in the hyperresponsiveness group, suggesting that high expression of TBXAS1 may be associated with aspirin hyporesponsiveness. miR-34b-3p may regulate the platelet and aspirin response by suppressing TBXAS1 expression and megakaryocyte proliferation.

microRNA biomarkers in colorectal cancer liver metastasis.

Liver metastasis is a primary factor of prognosis and long-term survival for patients diagnosed with colorectal cancer (CRC). Colorectal cancer liver metastasis (CRCLM), is a complex biological process involving multiple factors and steps, and its mechanisms are yet to be discovered. In recent years, small noncoding RNAs, especially microRNAs (miRNAs) have been proven to play an important role in tumorigenesis, progression and metastasis in a variety of cancers, including CRC. Increasing evidence suggests that miRNAs, including those from exosomes secreted by tumor cells in circulation, could be used as promising biomarkers in early cancer detection, treatment, and prognosis. In this review, we focus on the functional roles and clinical applications of miRNAs, especially those from circulating exosomes secreted by tumor cells related to CRCLM.

BP1 transcriptionally activates bcl-2 and inhibits TNFalpha-induced cell death in MCF7 breast cancer cells.

INTRODUCTION: We have previously shown that the Beta Protein 1 (BP1) homeodomain protein is expressed in 81% of invasive ductal breast carcinomas, and that increased BP1 expression correlates with tumor progression. The purpose of our current investigation was to determine whether elevated levels of BP1 in breast cancer cells are associated with increased cell survival. METHODS: Effects on cell viability and apoptosis of MCF7 cells stably overexpressing BP1 were determined using MTT and Annexin V assays, and through examination of caspase activation. TNFalpha was used to induce apoptosis. The potential regulation of apoptosis-associated genes by BP1 was studied using real-time PCR and western blot analyses. Electrophoretic mobility shift assays, site-directed mutagenesis, and transient assays were performed to specifically characterize the interaction of BP1 with the promoter of the bcl-2 gene. RESULTS: Stable overexpression of BP1 led to inhibition of apoptosis in MCF7 breast cancer cells challenged with TNFalpha. Increased BP1 resulted in reduced processing and activation of caspase-7, caspase-8, and caspase-9, and inactivation of the caspase substrate Poly(ADP-Ribose) Polymerase (PARP). Increased levels of full-length PARP and a decrease in procaspase-8 were also associated with BP1 overexpression. The bcl-2 gene is a direct target of BP1 since: (i) BP1 protein bound to a consensus binding sequence upstream of the bcl-2 P1 promoter in vitro. (ii) MCF7 cells overexpressing BP1 showed increased levels of bcl-2 mRNA and protein. (iii) Transient assays indicated that increased bcl-2 promoter activity is due to direct binding and modulation by BP1 protein. BP1 expression also prevented TNFalpha-mediated downregulation of bcl-2 mRNA and protein. CONCLUSION: These findings suggest mechanisms by which increased BP1 may impart a survival advantage to breast cancer cells, which could lead to increased resistance to therapeutic agents in patients.

Predictors of high on-aspirin platelet reactivity in elderly patients with coronary artery disease.

OBJECTIVES: Previous studies have illustrated the link between high on-aspirin platelet reactivity (HAPR) with increasing thrombotic risks. The aim of our study was to investigate relative risk factors of HAPR in elderly patients with coronary artery disease. METHODS: Elderly, hospitalized coronary artery disease patients on regular aspirin treatment were enrolled from January 2014 to September 2016. Medical records of each patient were collected, including demographic information, cardiovascular risk factors, concomitant drugs and routine biological parameters. Arachidonic acid (AA, 0.5 mg/mL) and adenosine diphosphate (ADP, 5 µmol/L) induced platelet aggregation were measured via light transmission assay (LTA) to evaluate antiplatelet responses, referred as LTA-AA and LTA-ADP. RESULTS: A total of 275 elderly patients were included, with mean age of 77.2±8.1 years, and males accounted for 81.8%. HAPR was defined as LTA-AA in the upper quartile of the enrolled population. HAPR patients tended to have lower renal function (P=0.052). Higher serum uric acid (SUA) level, as well as lower platelet count, hemoglobin and hematocrit were observed in HAPR patients, with a higher proportion of diuretics use (P<0.05). Multivariate analysis revealed that SUA (OR: 1.004, 95% CI: 1.000-1.007, P=0.048), platelet count (OR: 0.994, 95% CI: 0.989-1.000, P=0.045), hematocrit (OR: 0.921, 95% CI: 0.864-0.981, P=0.011) and concomitant P2Y12 receptor inhibitors use (OR: 1.965, 95% CI: 1.075-3.592, P=0.028) were correlated with HAPR. Spearman's correlation analysis demonstrated an inverse association of LTA-AA with hematocrit (r=-0.234, P<0.001), hemoglobin (r=-0.209, P<0.001) and estimated glomerular filtration rate (r=-0.132, P=0.031). CONCLUSION: SUA, platelet count, hematocrit and P2Y12 receptor inhibitors use were independently correlated with HAPR. These parameters might provide novel therapeutic targets for optimizing antiplatelet therapy.

Validation of aspirin response-related transcripts in patients with coronary artery disease and preliminary investigation on CMTM5 function.

Aspirin is widely used in the prevention of cardiovascular diseases, but the antiplatelet responses vary from one patient to another. To validate aspirin response related transcripts and illustrate their roles in predicting cardiovascular events, we have quantified the relative expression of 14 transcripts previously identified as related to high on-aspirin platelet reactivity (HAPR) in 223 patients with coronary artery disease (CAD) on regular aspirin treatment. All patients were followed up regularly for cardiovascular events (CVE). The mean age of our enrolled population was 75.80±8.57years. HAPR patients showed no significant differences in terms of co-morbidities and combined drugs. Besides, the relative expression of HLA-DQA1 was significantly lower in low on-aspirin platelet reactivity (LAPR) patients, when compared with HAPR and high normal (HN) group (p=0.028). What's more, the number of arteries involved, HAPR status and the relative expression of CLU, CMTM5 and SPARC were independent risk factors for CVE during follow up (p<0.05). In addition, overexpression of CMTM5 attenuated endothelial cells (ECs) migration and proliferation, with significantly decreased phosphorylated-Akt levels, while its inhibition promoted these processes in vitro (p<0.05).Our study provides evidence that circulating transcripts might be potential biomarkers in predicting cardiovascular events. CMTM5 might exert anti-atherosclerotic effects via suppressing migration and proliferation in the vessel wall. Nevertheless, larger-scale and long-term studies are still needed.