The Expression Profiles of MicroRNA Let-7a in Peripheral Blood Mononuclear Cells from Patients of Gastric Cancer with Neoadjuvant Chemotherapy.

BACKGROUND: The microRNA let-7a contains three copies of genes and is associated with various types of cancer, including gastric cancer. In this study, we aim to investigate the differential expression patterns of microRNA let7a in PBMCs from patients of gastric cancer (GC) before and after neoadjuvant chemotherapy. METHODS: The differential expression levels of let-7a were detected in PBMCs from 22 patients with GC before and after neoadjuvant chemotherapy by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The statistical analysis was performed with t-test and one-way AVOVA. RESULTS: MicroRNA let-7a level was significantly decreased in patients with GC after neoadjuvant chemotherapy (p < 0.05). In patients with GC, microRNA let-7a has different expression patterns with different neoadjuvant chemotherapy cycles. CONCLUSIONS: Our study demonstrated that microRNA let-7a was expressed differentially in patients with GC before and after neoadjuvant chemotherapy. These data supported that microRNA let-7a may have a potential role in efficacy assessment in patients with GC with neoadjuvant chemotherapy.

Linc-ROR induces epithelial-mesenchymal transition and contributes to drug resistance and invasion of breast cancer cells.

We aimed to investigate the role of large intergenic noncoding RNA regulator of reprogramming (linc-ROR) in the chemotherapy resistance of human breast cancer (BC) cells and its mechanism. A total of 142 patients diagnosed with BC in the First Affiliated Hospital, Zhejiang University between January 2012 and January 2014 were enrolled in our study. The BC tissues and the adjacent normal tissues (5 cm away from tumor tissue) of the enrolled patients were selected, and human BC cell lines (MCF10A, SK-BR-3, MCF-7, Bcap-37, MDA-MB-231, and T47D) were also selected. Quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay, and Transwell were applied in our study. Expression level of linc-ROR messenger RNA (mRNA) in BC tissues was clearly higher than that in adjacent normal tissues, and significant difference was found between expression level of linc-ROR mRNA and lymph node metastasis (all P < 0.05). Linc-ROR was highly expressed in others BC cell lines compared with that in immortalized mammary epithelial cells (MECs) MCF10A (both P < 0.05), while MDA-MB231 cell presented the higher expression (P < 0.001). Under different concentrations of 5-FU and paclitaxel in MDA-MB231 cell, E-cadherin mRNA and protein expressions increased gradually with the increase of concentrations, and Vimentin and N-cadherin mRNA and protein expressions decreased gradually with the decrease of concentrations (all P < 0.05). Compared with shCtrl group, MDA-MB231 cell in shROR group presented higher sensibility of 5-FU and paclitaxel with increased E-cadherin expression, decreased Vimentin and N-cadherin expression and invasion ability (all P < 0.05). Compared with vector cell, overexpressed linc-ROR cell presented decreased sensibility of 5-FU and paclitaxel with decreased E-cadherin expression, increased Vimentin, N-cadherin expression, and invasion ability (all P < 0.05). Our study demonstrated that linc-ROR is an important marker for multidrug resistance of BC, and its up-regulation is important for chemotherapy tolerance and invasion of BC.

Knockdown of dual specificity phosphatase 4 enhances the chemosensitivity of MCF-7 and MCF-7/ADR breast cancer cells to doxorubicin.

BACKGROUND: Breast cancer is the major cause of cancer-related deaths in females world-wide. Doxorubicin-based therapy has limited efficacy in breast cancer due to drug resistance, which has been shown to be associated with the epithelial-to-mesenchymal transition (EMT). However, the molecular mechanisms linking the EMT and drug resistance in breast cancer cells remain unclear. Dual specificity phosphatase 4 (DUSP4), a member of the dual specificity phosphatase family, is associated with cellular proliferation and differentiation; however, its role in breast cancer progression is controversial. METHODS: We used cell viability assays, Western blotting and immunofluorescent staining, combined with siRNA interference, to evaluate chemoresistance and the EMT in MCF-7 and adriamycin-resistant MCF-7/ADR breast cancer cells, and investigate the underlying mechanisms. RESULTS: Knockdown of DUSP4 significantly increased the chemosensitivity of MCF-7 and MCF-7/ADR breast cancer cells to doxorubicin, and MCF-7/ADR cells which expressed high levels of DUSP4 had a mesenchymal phenotype. Furthermore, knockdown of DUSP4 reversed the EMT in MCF-7/ADR cells, as demonstrated by upregulation of epithelial biomarkers and downregulation of mesenchymal biomarkers, and also increased the chemosensitivity of MCF-7/ADR cells to doxorubicin. CONCLUSIONS: DUSP4 might represent a potential drug target for inhibiting drug resistance and regulating the process of the EMT during the treatment of breast cancer.

Pegylated Liposomal Doxorubicin Versus Epirubicin as Adjuvant Therapy for Stage I-III Breast Cancer.

Background: Conventional anthracyclines, like epirubicin, are cornerstone drugs for breast cancer treatment of all stages, but their cumulative toxicity could cause life-threatening side effects. Pegylated liposomal doxorubicin (PLD), an effective anti-breast cancer drug, has lower toxicity than conventional anthracyclines. This retrospective study compared the efficacy and toxicity profiles between PLD and epirubicin as adjuvant therapy for breast cancer. Patients and Methods: A total of 1,471 patients diagnosed with stage I-III breast cancer between 2000 and 2018 were included in this study, among which 661 were treated with PLD and 810 with epirubicin, with 45.9 months as the median follow-up time. Anti-breast cancer efficacy was assessed with overall survival (OS) and disease-free survival (DFS), while cardiac toxicity was assessed with left ventricular ejection fraction (LVEF) and electrocardiogram (ECG). Results: The Kaplan-Meier method and Cox proportional hazards model revealed that there was no statistical difference in OS or DFS between patients treated with PLD and epirubicin, regardless of cancer stages or molecular subtypes (all p-values > 0.05). In addition, patients had significantly better LEVF and ECG data after adjuvant therapy with PLD (both p-values < 0.05). Conclusion: Based on the large sample size and the long follow-up time of this study, we conclude that PLD has a similar anti-breast cancer efficacy as epirubicin while inducing lower level of cardiac toxicity in Han Chinese. This study suggests that PLD-based adjuvant chemotherapy could be a better option than epirubicin for breast cancer patients especially with existing cardiac disease.

Duodenal gastrointestinal stromal tumor: clinical, pathologic, immunohistochemical characteristics, and surgical prognosis.

OBJECTIVE: Gastrointestinal stromal tumors (GISTs) occur rarely in the duodenum. The characteristics of duodenal GIST have not been well clarified. The aim of this study is to clarify the characteristics and surgical prognosis of patients with primary duodenal GIST. METHODS: Data of patients with surgically treated primary duodenal GIST were retrospectively analyzed. Immunohistochemical expressions of p53, p16, and Ki-67 were evaluated to explain the prognosis. RESULTS: Compared with gastric or small intestinal GISTs in historical studies, duodenal GISTs had a relatively smaller size, lower mitotic count, lower Ki-67 LI, lower p16 loss, and similar p53 expression. The 1- and 3-year recurrence-free survival rates of patients with complete resection were 100 and 95.2%. CONCLUSION: Patients with completely resected primary duodenal GIST seem to have a more favorable prognosis. This may be related to the different expressions of some immunohistological makers compared with GISTs of other locations.

Bcl-2 promotes metastasis through the epithelial-to-mesenchymal transition in the BCap37 medullary breast cancer cell line.

Metastatic breast cancer is one of the major types of cancer in women. However, despite being the focus of considerable research efforts, its molecular mechanism remains to be fully elucidated. The B-cell lymphoma/leukemia gene-2 (Bcl-2) protein is well known for its role in inhibiting programmed cell death/apoptosis. However, little is known concerning its function in cell invasion and migration. In the present study, cell migration and invasion assays revealed that anti-apoptotic Bcl-2 protein induced migration and invasion without affecting cell proliferation in the BCap37 breast cancer cell line. In addition, it was found that the overexpression of Bcl-2 in BCap37 cells increased metastasis to the lung in a mouse model. Using western blotting and RT q-PCR analysis, it was demonstrated that the overexpression of Bcl-2 inhibited the expression of E-cadherin, an epithelial marker, whereas it increased the levels of mesenchymal markers N-cadherin and vimentin. Therefore, the results suggested that Bcl-2 may induce cellular metastasis in breast cancer via the epithelial-to-mesenchymal transition.

Large intergenic non-coding RNA-ROR reverses gemcitabine-induced autophagy and apoptosis in breast cancer cells.

The purpose of this study was to elucidate the potential role of long intergenic non-protein coding RNA, regulator of reprogramming (linc-ROR) in gemcitabine (Gem)-induced autophagy and apoptosis in breast cancer cells. MDA-MB-231 cells were treated with short hairpin RNA (shRNA) to knockdown Linc-ROR expression in the presence of Gem. Gem treatment alone decreased cell survival and increased both apoptosis and autophagy. Gem treatment also increased the expression of LC3-II, Beclin 1, NOTCH1 and Bcl-2, but decreased expression of p62 and p53. Untreated MDA-MB-231 cell lines strongly expressed linc-ROR, but linc-ROR knockdown decreased cell viability and expression of p62 and p53 while increasing apoptosis. Linc-ROR knockdown also increased LC3-II/ß-actin, Beclin 1, NOTCH1, and Bcl-2 expression, as well as the number of autophagic vesicles in MDA-MB-231 cells. Linc-ROR negatively regulated miR-34a expression by inhibiting histone H3 acetylation in the miR-34a promoter. We conclude that linc-ROR suppresses Gem-induced autophagy and apoptosis in breast cancer cells by silencing miR-34a expression.

KLF4 downregulates hTERT expression and telomerase activity to inhibit lung carcinoma growth.

Krüppel-like factor 4 (KLF4) is a transcription factor that contributes to diverse cellular processes and serves as a tumor suppressor or oncogene in various cancers. Previously, we have reported on the tumor suppressive function of KLF4 in lung cancer; however, its precise regulatory mechanism remains elusive. In this study, we found that KLF4 negatively regulated hTERT expression and telomerase activity in lung cancer cell lines and a mouse model. In addition, the KLF4 and hTERT expression levels were significantly related to the clinicopathological features of lung cancer patients. Promoter reporter analyses revealed the decreased hTERT promoter activity in cells infected with Ad-KLF4, and chromatin immunoprecipitation analysis demonstrated that endogenous KLF4 directly bound to the promoter region of hTERT. Furthermore, the MAPK signaling pathway was revealed to be involved in the KLF4/hTERT modulation pathway. Forced expression of KLF4 profoundly attenuated lung cell proliferation and cancer formation in a murine model. Moreover, hTERT overexpression can partially rescue the KLF4-mediated suppressive effect in lung cancer cells. Taken together, these results demonstrate that KLF4 suppresses lung cancer growth by inhibiting hTERT and MAPK signaling. Additionally, the KLF4/hTERT/MAPK pathway is a potential new therapeutic target for human lung cancer.

EIF5A2 is a novel chemoresistance gene in breast cancer.

BACKGROUND: The eIF5A2 gene (encoding the eukaryotic initiation factor 5A2) located at 3q26 is a putative oncogene that is overexpressed in colon and rectal carcinomas, lung cancer and hepatocellular carcinoma. EIF5A2 overexpression correlates significantly with tumor metastasis and is an adverse prognostic marker. However, eIF-5A2 overexpression in breast cancer and its effect on chemotherapy are unknown. METHODS: We measured eIF-5A2 expression and doxorubicin sensitivity in different human breast cancer cell lines (Bcap-1937, HCC1937, and MCF-7). To investigate a role for eIF-5A2 in chemoresistance, cells were treated with eIF-5A2-siRNA, exposed to various concentrations of doxorubicin, and toxicity was assayed by CCK-8 (cell counting kit). RESULTS: The eIF-5A2 expression levels varied among breast cancer cells. Higher expression levels correlated with decreased doxorubicin sensitivity. Silencing of eIF-5A2 significantly improved doxorubicin toxicity in all three breast cancer cell lines. CONCLUSION: This study shows that eIF-5A2 plays an important role in doxorubicin chemoresistance in breast cancer cells.

MicroRNA-185 inhibits proliferation by targeting c-Met in human breast cancer cells.

MicroRNAs (miRNAs) are a group of small non-coding RNA molecules that have been shown to regulate the expression of genes involved in tumorigenesis. The relevance of miRNAs in the development, progression and prognosis of human breast cancer is not fully understood. miR-185 has been demonstrated to be involved in the pathogenesis of several types of cancers; however, its role in breast cancer has not yet been elucidated. In the present study, the expression of miR-185 was analyzed by quantitative polymerase chain reaction. In addition, an MTT assay and flow cytometry were used to determine the rates of cell proliferation and apoptosis. Protein expression was analyzed by western blotting and the target gene was confirmed using a luciferase reporter assay. The expression of miR-185 was found to be downregulated in the breast cancer tissues. The MTT assay revealed that overexpression of miR-185 inhibited the proliferation of MDF7 and SKBR3 cells. Furthermore, flow cytometric analysis demonstrated that increased expression levels of miR-185 promoted the apoptosis of breast cancer cells. In addition, c-Met expression was demonstrated to be significantly upregulated in breast cancer tissues and cells, and the c-Met gene was identified to be a target of miR-185. Therefore, the results demonstrated that miR-185 inhibited the proliferation of breast cancer cells by regulating the expression of c-Met, indicating its potential as a therapeutic target for breast cancer.

Tanshinone IIA blocks epithelial-mesenchymal transition through HIF-1α downregulation, reversing hypoxia-induced chemotherapy resistance in breast cancer cell lines.

The aim of the present study was to investigate the effects of tanshinone IIA (Tan IIA), an active constituent of Salvia miltiorrhiza Bunge, on epithelial-mesenchymal transition (EMT) and hypoxia-induced chemoresistance in breast cancer cells. To induce hypoxia, MCF-7 and HCC1973 cells were treated with 100 µM deferoxamine followed by doxorubicin (DOX). Cell viability and proliferation were examined using the CCK-8 and EdU assays, respectively. Western blot and immunofluorescence analyses of the expression of two EMT markers, E-cadherin and vimentin, were also carried out. The role of HIF-1α and TWIST in mediating the effects of Tan IIA was determined through siRNA. Based on the results, hypoxia-induced DOX resistance was observed in both MCF-7 and HCC1973 cells (both P=0.001), which was reversed with Tan IIA. Specifically, in hypoxic conditions, Tan IIA significantly decreased cell viability and proliferation (all P≤0.001), but not apoptosis. Hypoxia also significantly reduced E-cadherin and increased vimentin protein levels (P≤0.005), which returned to control levels with Tan IIA. In addition, silencing both HIF-1α and TWIST expression abrogated the effects of Tan IIA on cell viability. Taken together, Tan IIA ameliorated hypoxia-induced DOX resistance and EMT in breast cancer cell lines, which may be attributed to the downregulation of HIF-1α expression. Further in vivo studies, however, are required to fully elucidate the therapeutic potential of Tan IIA in increasing the sensitivity of breast cancer cells to chemotherapy.

Prognostic value of preoperative inflammatory markers in Chinese patients with breast cancer.

Cancer-associated inflammation is a key determinant of disease progression and survival in most cancers. The aim of our study was to assess the predictive value of preoperative inflammatory markers, such as the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio, red cell distribution width (RDW), and mean platelet volume, for survival in breast cancer patients. In total, 608 breast cancer patients operated on between January 2009 and December 2011 were included in this observational study. The association between preoperative inflammatory markers and survival outcomes was analyzed. Patients with high NLR (>2.57) or high RDW (>13.45%) showed a significantly lower overall survival rate than those with lower NLR (≤2.57) or lower RDW (≤13.45%). NLR and RDW, along with node stage and molecular subtypes, were independent prognostic factors. There was a significant survival difference according to NLR in the luminal A and triple-negative subtypes (93.3% versus 99.3%, P=0.001; 68.8% versus 95.1%, P=0.000, respectively). The triple-negative subtype was the only subtype in which higher RDW patients showed significantly poor prognosis (81.3% versus 95.5%, P=0.025). Pre-operation NLR and RDW is a convenient, easily measured prognostic indicator for patients with breast cancer, especially in patients with the triple-negative subtype.

Cruciferous vegetables intake is inversely associated with risk of breast cancer: a meta-analysis.

PURPOSE: The objective of the study was to examine the associations of cruciferous vegetables intake with risk of breast cancer. METHODS: Studies were identified by searching PubMed databases and screening the references of retrieved articles and reviews. Summary odds ratios (ORs) for the highest versus lowest cruciferous vegetables consumption levels were calculated using fixed or random effects models depending on heterogeneity between studies. Heterogeneity among studies was examined using Q and I(2) statistics. Publication bias was assessed using the Egger's and Begg's tests. RESULTS: Thirteen epidemiologic studies (11 case-control and 2 cohort studies) were included in the meta-analysis. The combined results from all studies indicated that high cruciferous vegetables intake was significantly associated with reduced breast cancer risk (RR = 0.85, 95% CI = 0.77-0.94). CONCLUSION: Findings from this meta-analysis suggest that cruciferous vegetables consumption may reduce the risk of breast cancer. Because of the limited number of studies, further prospective studies are needed to explore the protective effect of cruciferous vegetables on breast cancer.

Lin28 mediates radiation resistance of breast cancer cells via regulation of caspase, H2A.X and Let-7 signaling.

Resistance to radiation therapy is a major obstacle for the effective treatment of cancers. Lin28 has been shown to contribute to breast tumorigenesis; however, the relationship between Lin28 and radioresistance remains unknown. In this study, we investigated the association of Lin28 with radiation resistance and identified the underlying mechanisms of action of Lin28 in human breast cancer cell lines. The results showed that the expression level of Lin28 was closely associated with resistance to radiation treatment. The T47D cancer cell line, which highly expresses Lin28, is more resistant to radiation than MCF7, Bcap-37 or SK-BR-3 cancer cell lines, which have low-level Lin28 expression. Transfection with Lin28 siRNA significantly led to an increase of sensitivity to radiation. By contrast, stable expression of Lin28 in breast cancer cells effectively attenuated the sensitivity to radiation treatment. Stable expression of Lin28 also significantly inhibited radiation-induced apoptosis. Moreover, further studies have shown that caspases, H2A.X and Let-7 miRNA were the molecular targets of Lin28. Stable expression of Lin28 and treatment with radiation induced H2AX expression, while inhibited p21 and γ-H2A.X. Overexpression of Let-7 enhanced the sensitivities to radiation in breast cancer cells. Taken together, these results indicate that Lin28 might be one mechanism underlying radiation resistance, and Lin28 could be a potential target for overcoming radiation resistance in breast cancer.

Lin28 mediates paclitaxel resistance by modulating p21, Rb and Let-7a miRNA in breast cancer cells.

Resistance to chemotherapy is a major obstacle for the effective treatment of cancers. Lin28 has been shown to contribute to tumor relapse after chemotherapy; however, the relationship between Lin28 and chemoresistance remained unknown. In this study, we investigated the association of Lin28 with paclitaxel resistance and identified the underlying mechanisms of action of Lin28 in human breast cancer cell lines and tumor tissues. We found that the expression level of Lin28 was closely associated with the resistance to paclitaxel treatment. The T47D cancer cell line, which highly expresses Lin28, is more resistant to paclitaxel than the MCF7, Bcap-37 or SK-BR-3 cancer cell lines, which had low-level expression of Lin28. Knocking down of Lin28 in Lin28 high expression T47D cells increased the sensitivity to paclitaxel treatment, while stable expression of Lin28 in breast cancer cells effectively attenuated the sensitivity to paclitaxel treatment, resulting in a significant increase of IC50 values of paclitaxel. Transfection with Lin28 also significantly inhibited paclitaxel-induced apoptosis. We also found that Lin28 expression was dramatically increased in tumor tissues after neoadjuvant chemotherapy or in local relapse or metastatic breast cancer tissues. Moreover, further studies showed that p21, Rb and Let-7 miRNA were the molecular targets of Lin28. Overexpression of Lin28 in breast cancer cells considerably induced p21 and Rb expression and inhibited Let-7 miRNA levels. Our results indicate that Lin28 expression might be one mechanism underlying paclitaxel resistance in breast cancer, and Lin28 could be a potential target for overcoming paclitaxel resistance in breast cancer.

Synthesis and photo-degradation application of WO3/TiO2 hollow spheres.

A WO(3)/TiO(2) composite, hollow-sphere photocatalyst with average diameter of 320 nm and shell thickness of 50 nm was successfully prepared using a template method. UV-vis diffuse reflectance spectra illustrated that the main absorption edges of the WO(3)/TiO(2) hollow spheres were red-shifted compared to the TiO(2) hollow spheres, indicating an extension of light absorption into the visible region of the composite photocatalyst. The WO(3) and TiO(2) phases were confirmed by X-ray diffraction analysis. BET isotherms revealed that the specific surface area and average pore diameter of the hollow spheres were 40.95 m(2)/g and 19 nm, respectively. Photocatalytic experiments indicate that 78% MB was degraded by WO(3)/TiO(2) hollow spheres under visible light within 80 min. Under the same conditions, only 24% MB can be photodegraded by TiO(2). The photocatalytic mineralization of MB, catalyzed by TiO(2) and WO(3)/TiO(2), proceeded at a significantly higher rate under UV irradiation than that under visible light, and more significant was the increase in the apparent rate constant with the WO(3)/TiO(2) composite semiconductor material which was 3.2- and 3.5-fold higher than with the TiO(2) material under both UV and visible light irradiation. The increased photocatalytic activity of the coupled nanocomposites was attributed to photoelectron/hole separation efficiency and the extension of the wavelength range of photoexcitation.